Navigation device

0001The present invention relates to a navigation device for indicating the order of priority of goals on a map picture.

0002In conventional navigation devices, a user inputs the goals before departure. Therefore, a route is set from a point of departure to the goals, and the route is guided. The goals input before departure are a final goal and passing places to the final goal.

0003The user may drop in e.g. a restaurant or a shop in his route to the final goal. In this case, the user inputs the places to drop in. Therefore, the navigation device interrupts the guidance operation up to the final goal. And then, the route to the place where the user drops in is guided. When the places to drop in are inputted, first, the user inputs the genre. The navigation device searches the places that conform the genre. Then, the places that conform the genre are indicated on the map picture.

0004According to the conventional navigation devices, however, a predetermined marks are simply indicated on places that conform the designated genre. When a plurality of marks are indicated, therefore, it is difficult for the user to select quickly a place that conforms his desire. Therefore, the user is forced to select a place out of the marked places whether it conforms his desire or not. Or, the user must once stop his car. Then, the user calls descriptive images related to the marked places, and must to determine his desired place while looking at the descriptive images.

0005When places that conform the designated genre are indicated on the conventional navigation device, furthermore, the reduced scale of a map picture is that of the initial picture or that of the map picture that had been displayed till then. Many marks are indicated when the map picture has a large scale. Therefore, the user finds it difficult to select a goal out of them. When the map picture has a small scale, on the other hand, there are often no places that conform the designated genre in this map picture. The user therefore must change the scale of the map picture by hand so that fit number of marks could be indicated for being easily recognized.

0006From the post-published EP-A-0 672 890 (a document falling under Article 54(3) EPC) a sight-seeing tour guide system is known. The guide system comprises: guide data storage means stored with guide data for guiding an object along a road or an object on a street or in an area; guidance output means for outputting a guidance of the object to be guided; present position detecting means for detecting and tracing a present position; guide output means including first search means for searching the guidance object on the basis of the present position obtained by the present position detecting means, and second search means for searching the guidance object within a range different from that of the first search means, for reading out and outputting the object, which is searched by the search means, from the guide data storage means; and a manual key for instructing the search of the second search means. The guide output means searches the guidance object by the second search means in place of the first search means, when the manual key is operated, so that the guidance object is extracted and outputted for the guidance to the guide output means.

0007The object of the present invention is to easily and quickly select the goal that conforms the desire of the user, and to automatically adjust the scale of the map picture on which the goals are indicated.

0008The object is achieved by the features of the claims. According to the present invention, the order of priority of goals is determined from a relationship between the data related to goals and the data related to a reference position, and is indicated. Thus, the order of priority of objective places is indicated depending upon the desire of the user, such as distance, kind of business, etc. The user is then allowed to select the goals that conform his desire within short periods of time. A navigation system according to the invention is defined in claim 1.

0009According to the present invention, furthermore The scale of the map picture indicating the goals may be automatically adjusted so that it can be easily watched by the user. Therefore, the user is not required to adjust the scale by his hand. <ul id="ul0001" list-style="none" compact="compact"><li>Fig. 1 is a diagram illustrating the whole circuit of a navigation device;</li><li>Fig. 2 is a diagram illustrating data files stored in an external storage medium;</li><li>Fig. 3 is a diagram illustrating a data file F16 of objective places;</li><li>Fig. 4 is a diagram illustrating data stored in a RAM 4;</li><li>Fig. 5 is a flow chart illustrating the whole processing;</li><li>Fig. 6 is a flow chart illustrating the processing for setting objective places executed according to a first embodiment;</li><li>Fig. 7 is a flow chart illustrating the processing for determining a reference for search executed according to the first embodiment;</li><li>Fig. 8 is a flow chart illustrating the processing for determining a reference position executed according to the first embodiment;</li><li>Fig. 9 is a flow chart illustrating the processing for automatic setting executed according to the first embodiment;</li><li>Fig. 10 is a flow chart illustrating the processing for correcting the reference position executed according to the first embodiment;</li><li>Fig. 11 is a flow chart illustrating the processing for searching objective places executed according to the first embodiment;</li><li>Fig. 12 is a flow chart illustrating the processing for determining the order of priority executed according to the first embodiment;</li><li>Fig. 13 shows a part of a flow chart illustrating the processing for changing the distance to the objective place executed according to the first embodiment;</li><li>Fig. 14 shows the rest of the flow chart illustrating the processing for changing the distance to the objective place executed according to the first embodiment;</li><li>Fig. 15 is a flow chart illustrating the processing for determining the order of priority executed according to the first embodiment;</li><li>Fig. 16 is a flow chart illustrating the processing for indicating the objective place executed according to the first embodiment;</li><li>Fig. 17 illustrates a picture of display 33 indicating objective places;</li><li>Fig. 18 illustrates a picture of display 33 showing a list of objective places;</li><li>Fig. 19 illustrates a picture of setting the objective places indicated on the display 33;</li><li>Fig. 20 illustrates a picture of display 33 of when the objective place is changed;</li><li>Fig. 21 is a flow chart illustrating the processing for storing objective places executed according to the first embodiment;</li><li>Fig. 22 is a flow chart illustrating the processing for setting objective places executed according to a second embodiment;</li><li>Fig. 23 is a flow chart illustrating the processing for determining a reference for search executed according to the second embodiment;</li><li>Fig. 24 is a flow chart illustrating the processing for searching objective places executed according to the second embodiment;</li><li>Fig. 25 is a flow chart illustrating the processing for indicating objective places executed according to the second embodiment;</li><li>Fig. 26 is a flow chart illustrating the processing for adjusting the scale executed according to the second embodiment;</li><li>Fig. 27 is a diagram illustrating coordinates of a present position and an objective place indicated on the display 33;</li><li>Fig. 28 is a picture of the display 33 on which objective places are indicated;</li><li>Fig. 29 is a flow chart illustrating the processing for storing objective places executed according to the second embodiment;</li><li>Fig. 30 is a flow chart illustrating the processing for adjusting the scale executed according to a third embodiment;</li><li>Fig. 31 is a flow chart illustrating the processing for adjusting the scale executed according to a fourth embodiment;</li><li>Fig. 32 illustrates a picture of the display 33 on which a small area 90 is shown;</li><li>Fig. 33 is a flow chart illustrating'the processing for adjusting the scale executed according to a fifth embodiment;</li><li>Fig. 34 illustrates a data table used for adjusting the scale;</li><li>Fig. 35 shows a part of a flow chart illustrating the processing for searching objective places executed according to a sixth embodiment;</li><li>Fig. 36 is a flow chart illustrating the processing for setting objective places executed according to a seventh embodiment; and</li><li>Fig. 37 is a flow chart illustrating the processing for adjusting the scale executed according to a ninth embodiment.</li></ul><ul id="ul0002" list-style="none" compact="compact"><li>POS: POSITION, PRO: PROCESSING, COM: COMMUNICATION,</li><li>TRANS: TRANSMISSION, REC: RECEPTION, OBJ: OBJECTIV,</li><li>REF: REFERENCE, DET: DETERMINE, No: NUMBER,</li><li>DIST: DISTANCE.</li></ul>

0010An user inputs the genre of objective places, range to be searched and any other references of search (step 102 in Fig. 6). Then, a reference position that is set by the user or is automatically set becomes the center of search area (step 104 in Fig. 6). Objective places are searched from the search area (step 106 in Fig. 6). Those places that conform the reference for search are selected out of the searched objective places, and are weighted depending upon the reference of search (steps 230, 234, 238, 254, 258, 262 in Figs. 13 and 14). Thus, the order of priority is given to the objective places (step 108 in Fig. 6). The searched objective places are indicated together with the order of priority (step 110 in Fig. 6). The user selects a desired objective place with reference to the order of priority that is indicated (step 112 in Fig. 6). Selected objective place is stored (step 112 in Fig. 6). Then, the route is navigated up to the objective places that are stored (Fig. 5).

0011The user inputs the genre of objective places (step 402 in Fig. 22). The data related to the objective places are searched depending upon the designated genre (step 404 in Fig. 22). The searched objective places are indicated on a display 33 (step 406 in Fig. 22). At this moment, the reduced scale of the map is automatically adjusted, and searched objective places of a number greater than Z are indicated on the map picture (steps 454 and 456 in Fig. 26).

0012Here, the goals include a final goal, passing places and objective places. The final goal is a place at which the user will finally arrive relying upon the navigation device. A passing place or an objective place may often be the final goal. The passing places are those points where the user will pass in his course to the final goal. The user passes through the passing places in his course to the final goal. The final goal and the passing places are input through the operation for setting the goals before the departure. The objective places have not been scheduled before the departure, and are places where the user suddenly wish to drop in while driving through the route to his final goal.

1. Whole Circuit.

0013Fig. 1 is a diagram illustrating the whole circuit of the navigation device. A central processing unit 1 includes a CPU 2 which controls the operation of the navigation device and executes the arithmetic operation. ROMs 3 and 5 store system programs executed by the CPU 2, a variety of parameters (data), and data for indication control, voice guidance control, route guidance control and map indication control. A RAM 4 stores the data input from external units, a variety of parameters (data) used for arithmetic operation and the results of operation. A time-keeping device generates data related to the time. A sensor input interface 7 receives the detection data from an absolute direction sensor 21, a relative direction sensor 22, a distance sensor 23 and an acceleration sensor 24 in a present position detection device 20, and sends the data to the CPU 2. A communication interface 8 transmits and receives various data to and from the units connected thereto via a data bus 28.

0014An image processor 9 reads the image data stored in an image memory 10 and sends them to a display 33. The display 33 is a device capable of displaying image and may be a CRT, a liquid crystal display or a plasma display, etc.. The image memory 10 stores image data displayed on the display 33, and transmits and receives image data to and from the image processor 9. In response to an instruction from the CPU 2, the image processor 9 converts the data related to goals and data related to roads into data for display, and forms image data to be displayed on the display 33. At this moment, surrounding images of the picture on the display 33 are also formed and are stored in the image memory 10. Therefore, it is enabled to scroll the picture. A voice processor 11 receives data related to waveforms of synthesized voice read out by the CPU 2 from the ROMs 3 and 5, forms analog voice waveforms, and sends them to a speaker 13.

0015The present position detection device 20 detects the present position of the car, and obtains the data related to longitude and latitude. The absolute direction sensor 21 is for example a terrestrial magnetism sensor. And this sensor 21 detects for example terrestrial magnetism, and outputs data that represents south-north direction which serves as an absolute direction. The relative direction sensor 22 is for example an angle-of-steering sensor which detects the angle of steering, or a gyroscopic device such as a piezoelectric oscillation gyroscope. And this sensor 22 outputs data representing a difference in the direction of progress of the car from the absolute direction detected by the absolute direction sensor 21. The distance sensor 23 is for example a digital counter which is interlocked to an odometer, and outputs data related to a distance traveled by the car. The acceleration sensor 24 is for example a semiconductor acceleration sensor, and detects the acceleration of the car.

0016A GPS reception device 25 receives signals from the GPS (global positioning system), and outputs data related to the position. A beacon reception device 26' receives correction data from the GPS and beacon waves from an information offering system such as VICS (vehicle information and communication system), and outputs the received data. A data transmission/reception device 27 transmits and receives data related to the present position to and from a bidirectional system for offering data related to the present position.

0017A data communication device 30 transmits and receives signals to and from VICS and ATIS (advanced traffic information system). A data transmission/reception unit 31 is, for example, a transmitter/receiver of VICS, and a telephone originating unit 32 is, for example, a communication unit of ATIS.

0018A transparent touch panel 34 is provided on the display 33. The touch panel has transparent touch switches that are arranged on a plane in the form of a matrix. A printer 35 prints various data such as map and guide to facilities that are received through the communication interface 8. A record card reader 36 reads a recording medium of the shape of a card such as IC card, ROM card, memory card and the like cards. A CD-ROM driver 37 is a device for reading CD-ROM which is a recording medium of the form of CD (compact disk). The CR-ROM driver 37 may be replaced by a reader for reading a recording medium such as an optical disk or a magnetic disk other than the CD-ROM.

0019An audio recognition unit 38 converts the voice picked up by a microphone 39 into digital signals, and discriminates whether a voice that is in agreement with a predetermined command is input or not. When the voice that is in agreement with the command is input, the audio recognition unit 38 sends command data to the CPU 2. The audio recognition unit 38 may be either of a system for recognizing specified talkers or of a system for recognizing unspecified talkers.

0020An operation switch 40 is a wired remotely controlled switch, a wireless remotely controlled switch or a manual switch arranged to surround the display 33. The operation switch 40 is used for instructing operations other than the contents operated on the touch panel 34 such as menu display, picture quality adjustment, starting of operation for setting the goals, etc.

2. External Storage Medium

0021The external storage medium such as the above-mentioned card-type storage medium or the CD-ROM stores various data files that are shown in Fig. 2. A map data file F1 stores map data such as road map of the whole of a country. An intersection data file F2 stores data related to intersections such as positions and names of intersections. A node data file F3 stores data related to nodes set on the roads. A road data file F4 stores data related to the roads such as positions and kinds of the roads, number of lanes, connection among the roads, etc. A photographic data file F5 stores picture data of photographs of various facilities, sight-seeing resorts, principal intersections, etc..

0022The goal data file F6 stores the data related to goals, names of goals, and data representing goals such as marks and figures. The data related to the goals include places of principal sight-seeing resorts, buildings, companies and sites of businesses listed in a telephone book, kinds of facilities and businesses, etc. In a processing for setting the goals (step 51) that will be described later, the final goals or the passing places are searched from the goal data file F6. A guide point data file F7 stores the data such as the contents of guide boards installed along the road and guide data related to branching points, etc.. A detailed goal data file F8 stores detailed data related to the goals that are stored in the goal data file F6. A road name data file F9 stores the data related to the names of principal roads in the road data stored in the road data file F4. A branching point name data file F10 stores the data related to the names of principal branching points. An address data file F11 stores the address data for searching the goal data stored in the goal data file F6 based upon addresses.

0023A toll number/local office number list file F12 stores the data related to toll number and local office number of the goals stored in the goal data file F6. A private phone number data file F13 stores the data related to private phone numbers of clients, etc. The phone number data are input by the user through manual operation. A mark data file F14 stores the data of positions and names related to marked points or points which the user desires storing to the RAM 4. These data are input by the user through manual operation. A point data file F15 stores detailed data of marked points stored in the mark data file F14.

0024An objective place data file F16 stores the data related to positions of objective places such as gas stations, convenience stores, parking zones, etc. and their descriptions. A processing for setting the objective places (step 100) that will be described later determines the places to drop in out of the objective places stored in the objective place data file F16. The objective place data file F16 stores the data related to points or facilities that are not stored in the goal data file F6. The data stored in the objective place data file F16 may often be partly or entirely overlapping on the data of goals stored in the goal data file F6.

0025The map data file F1 stores map data on a plurality of different scales for the same area. For instance, the map data file F1 stores map data of seven different scales, e.g., a scale of 1 to 10,000, a scale of 1 to 20,000, a scale of 1 to 40,000, a scale of 1 to 80,000, a scale of 1 to 160,000, a scale of 1 to 320,000 and a scale of 1 to 640,000. The greater the scale, the finer the map; i.e., the map contains data of narrow roads and local points.

0026The coordinates of road data and goal data stored in the data files are those of longitude and latitude as well as those that are determined on the coordinate system depending upon the maps of different scales. Therefore, there are stored, for each goal, the data related to coordinates of longitude and latitude as well as a plurality of coordinate data for each scale. The coordinate systems of the maps are determined using predetermined reference points in the maps that are stored as origins. The reference point remains the same irrespective of the scales of the maps. An x-y coordinate system is set on the image of a frame on the display 33. The coordinates of points are determined based on the x-y coordinate system. The picture of a frame on the display 33 has a predetermined size. When the map has different scales, therefore, the point on the same coordinate could become a different point. For example, a point on a coordinate (Xt, Yt) on the map drawn on a scale of 1 to 20,000 could become (2Xt, 2Yt) on a map drawn on a scale of 1 to 10,000.

3. Objective Place Data File

0027Fig. 3 illustrates detailed contents stored in the objective place data file F16. The objective places are classified into a plurality of genres. The data related to the number of genres JN represent the number of classifications. The genres stand for kinds of facilities or places where the user may drop in while driving. The genres are concerned to, for example, gas stations, convenience stores, parking zones, motels, hotels, restaurants, hamburger shops, coffee shops, railway stations, entrances to subway stations, hospitals, parks, police stations, post offices, pools, tennis courts, golf courses, golf practice ranges, temples and shrines, drug stores, pharmacies, etc. The genres J1 to Jn store genre code number data JC, data m related to the number of objective places, and data L1 to Lm related to the list of objective places, that are determined for each of the genres.

0028The data L1 to Lm related to the list of objective places store the data MM related to the names of objective places, the data MT related to the phone numbers of objective places, the data MZ related to coordinates of objective places on the map, and detailed data MD of objective places for each of the objective places of a number m. The data MM related to the names of objective places store the data such as characters, figures and marks representing the objective places. The data MD related to the objective places include detailed data related to objective places that are classified into a plurality of items. These items serve as conditions for selection, and include fees of objective places, capacities of facilities (number of cars that can be parked, number of persons that can be accommodated, width, height, length of a car that can be parked, etc.), brands (names of companies supplying petroleum to the gas stations, names of chain stores, etc.), addresses, contents of services, whether a parking lot is available or not, business time, kinds of dishes served in restaurants, data related to restaurants (whether they are of high grades or not, whether they are chain shops or not, whether famous cooks are employed or not), names of convenience stores, etc.

4. Data Groups

0029Fig. 4 illustrates groups of data stored in the RAM 4. Onto the external data GD are copied whole or part of the data stored in the external storage medium. The external data GD are read out by the above-mentioned record card reader 36 or the CD-ROM driver 37. The data MP related to the present position are the one representing the present position of the car and are detected by the present position detection device 20. The data ZD related to the absolute direction are those indicating the south-and-north direction, and are found based upon the data from the absolute direction sensor 21. The data θ 1 related to the angle of relative direction represent the angle of direction of progress of the car relative to the absolute direction, and are found based upon the data from the relative direction sensor 22. The data ML related to the distance traveled represent the distance traveled by the car and are found based upon the data from the distance sensor 23. The data ma related to acceleration represent acceleration of the car, and are detected by the acceleration sensor 24. The data PI related to the present position are input from the beacon reception device 26 or the data transmission/reception device 27. The VICS data VD are those of VICS input from the data transmission/reception unit 31. The ATIS data are those of ATIS input from the telephone originating unit 32. The goal data TP are those related to the goals such as positions and names of the goals, and are input by the user.

0030The data SP related to objective places are those related to the objective places such as positions and names of the objective places, and are input by the user. The guide route data MW are those of a route which is most desired, shortest or is recommended to arrive at the goal or the objective place. The genre code number JC is input through a processing for selecting the objective places that will be described later. The area designation data AS designate the area to be searched, and are input through the processing for selecting the objective places. The sub-reference data KS are for searching the objective places. The sub-reference data KS may often be stored in a plural number.

0031The reference position data KP represent a reference position for searching the objective places. The data RD related to roads represent whether the road on which the car is running is an expressway or a highway. The running speed data V represent the running speed of the car. The data KA related to the area to be searched are coordinate data of the area of the objective place to be searched. The data KM related to the objective place to be searched are those of the objective place searched from the external data GD.

0032The data TK related to the distance to the objective place represent a distance to the objective place to be searched. The data UN related to the order of priority denote the order of priority given to the objective places to be searched. The data θ 2 related to the angle of objective place represent the angle of the objective place to be searched relative to the absolute direction. The data θ related to the direction of objective place represent the angle of objective place to be searched relative to the direction of progress of the car. The keep the goal data MK are keeping data of the goal data TP, and are preserved prior to inputting the objective places.

0033The data (Xna, Yna) related to a coordinate difference represent a difference between the coordinates of the present position and the coordinates of the objective place. The data (Xka, Yka) related to a maximum coordinate difference represent a maximum value among the data related to coordinate differences. The distance data L is one of the data TK related to the distances to the objective places. In addition to the above, the RAM 4 stores the data for executing a variety of processings as well as data of variables (not shown).

5. Whole Processing

0034Fig. 5 is a flow chart illustrating the whole processing executed by the CPU 2. This processing starts upon making the power source circuit and terminates upon breaking the power source circuit. Upon starting the program, the CPU 2, RAM 4 and image memory 9, etc. are initialized. Then, a processing for obtaining the present position (step 50), a processing for setting the goal (step 51), a processing for searching the route (step 52) and a processing for indicating the guide (step 53) are executed repetitively.

0035In the processing for obtaining the present position (step 50), the present position of the car is calculated based upon the data sent from the present position detection device 20. In this processing (step 50), the latitude and longitude are calculated based on the data input from the GPS reception device 25. Based upon the latitude and longitude, the data (X, Y) related to the coordinates of longitude and latitude of the present position are formed. The data related to the coordinates of longitude and latitude are converted into orthogonal coordinate data (X0, Y0) of a coordinate system for each of the reduced scales. The data related to the coordinates of longitude and latitude and the data related to the orthogonal coordinates are stored in the RAM 4 as the data MP related to the present position. The data MP related to the present position are corrected by the data related to the present position from the beacon reception device 26 or the data transmission/reception device 27.

0036Operation is further carried out to discriminate the present position (position of the car) that has moved based upon the data ZD related to the absolute direction, data SD related to the relative direction and the data ML related to the distance of travel. The present position (position of the car) found through this operation is collated with the map data in the external data GD and is corrected; i.e., the present position is correctly indicted on the map picture. Owing to this processing, the present position of the car is correctly found even when GPS signals cannot be received as in running through a tunnel. The data ML related to the distance of travel is corrected by the acceleration data ma, therefore, error due generated by for example slip of the tires is eliminated.

0037In the processing for setting the goal (step 51), the input image of the goal is shown on the display 33 upon manipulation by the user. The user designates any one of the address, phone number or name to thereby designate the goal. Moreover, when a genre is selected from a menu of genres related to sight-seeing resorts, facilities, etc., a list of a plurality of goals stored in the selected genre is shown on the display 33. Through another manipulation, furthermore, there are shown detailed contents of the goals. After the goal is selected, the operation is carried out to determine the goal, whereby the data related to the determined goal are stored in the RAM 4 as the goal data TP. A final goal and at least a passing place may be registered as goals. In the processing for setting the goal (step 51), further, a processing for setting the objective places (step 100) is executed.

0038The goals and objective places are set by touch operation using the touch panel 34 or by operating the switch 40 by hand, or are set by voice using the audio recognition unit 38. The operation switch 40 is provided with change-over switches 41 and 42. The manual operation and the voice operation are changed over by using the change-over switch 41. The operation for setting the goals and the operation for setting the objective places are changed over by the change-over switch 42. The processing for setting the goals (step 51) is jumped over when neither the operation for setting new goals nor the operation for setting new objective places is executed.

0039In the process for searching the route (step 52), a guide route is formed from the point of departure to the final goal or a guide route is formed from the present position to the objective place. The road number data of roads constituting the guide route are arranged in order, and the thus arranged road number data are stored in the RAM 4 as the guide route data MW. The processing for searching the route (step 52) is jumped over when there is no change in the guide route.

0040In the processing for indicating the guide (step 53), a guide route found by the processing for searching the route (step 52) is indicated by a thick red line on the map picture shown on the display 33. Then, the guide for driving the car along the guide route is produced in the form of voice from the speaker 13 or is indicated on the map picture. In the following embodiments, the map picture shown by the processing for indicating the guide (step 53) is automatically scrolled such that the present position is at the center of the picture at all times.

0041Through the repetition of the above-mentioned processings, the guide route to the goals or to the object places input by the user, the present position of the car and the running direction are indicated on the map picture shown on the display 33. The present position is corrected as the car continues to run. As the car approaches an intersection or a branching point, furthermore, the guide is offered in the form of voice or indication.

6. First Embodiment

0042In a first embodiment, the objective places are searched in compliance with a reference for search, and the order of priority is imparted to the object places that are searched. The first embodiment executes the following processing in the whole processing.

7. Processing for Setting Objective Places (First Embodiment)

0043Fig. 6 is a flow chart of the processing for setting the objective places (step 100) executed in the processing for setting the goals (step 51). As described earlier, the objective places are goals that were not scheduled before the departure but are places where the user may happen to drop in while running along the route to the final goal. Therefore, the objective places are set through another operation after the final goal and the passing places are set.

0044This processing is commenced when it is requested to execute the operation for setting the objective places by manipulating the change-over switch 42. The operation for setting the objective places is often carried out while driving the car. When it is instructed to start this processing, therefore, the voice operation mode is automatically set. When the change-over switch 41 is operated to request the manual operation mode, the operation for setting the objective places is carried out by manipulating the switch 40 by hand. This processing may be executed in response to an instruction by voice. This makes the operations of the change-over switches 41, 42 unnecessary.

0045The processing for setting the objective places (step 100) is repetitively executed together with the processing for obtaining the present position (step 50), processing for searching the route (step 52), and processing for indicating the guide (step 53). When the car has approached the intersection or the branching point while executing the operation for setting the objective places, the operation for setting the objective places is interrupted for several seconds. During this period, the guide related to the intersection or the like may be offered by voice and indication.

0046In the processing for setting the objective plades (step 100), a processing for determining a reference for searching the objective places (step 102), a processing for determining a reference position in a range in which the objective places are searched (step 104), a processing for searching the objective places according to the reference for search (step 106), a processing for determining the order of priority for the objective places that are searched (step 108), a processing for indicating the objective places to which the order of priority is given (step 110), and a processing for storing an objective place selected by the user (step 112) are sequentially executed.

8. Processing for Determining Reference for Search (First Embodiment)

0047Fig. 7 is a flow chart illustrating the processing for determining the reference for search (step 102). In a processing for inputting the genre (step 120), an command signal is sent from the CPU 2 to the voice processor 11, and an inquiry is sounded from the speaker 13 saying, for example, "which genre is it?". When a voice signal is input to the CPU 2 from the audio recognition unit 38 during a predetermined standby period, the voice data that are input are converted into code data. The code data are collated with the genre code number data JC in the objective place data file F16. The genre code number data JC in agreement with the voice that is input are stored in the RAM 4. When, for instance, the user pronounces "gas station", the genre code number data JC of a gas station is stored in the RAM 4.

0048When the voice operation is not carried out, the user manipulates the keys of the touch panel 34. Then, a menu of genres is shown on the display 33. The user then selects a genre out of the genres in the menu.

0049In a processing for inputting the area (step 122), a command signal is sent from the CPU 2 to the voice processor 11, and the voice is sounded from the speaker 13 saying, for example, "Designate the area to be searched, please". When a voice signal is input to the CPU 2 from the audio recognition unit 38 during a predetermined standby period, the voice data that are input are converted into data AS for designating the area, and then the data AS is stored in the RAM 4. It is also allowable to search the objective places from all of the data instead of designating the area. With the area being set first, however, the processing speed can be increased.

0050The area to be searched is designated by a reduced scale of the map, by a circular range or by a square range. When the area to be searched is to be designated by the reduced scale of the map, the predetermined words for selecting the reduced scales are used. When the user pronounces the words, the data of a corresponding reduced scale are stored in the RAM 4 as the data AS for designating the area. Or, the scale is stepwisely decreased every time when the user pronounces "wide", and is stepwisely increased every time when the user pronounces "details".

0051When the area to be searched is designated by a circular range or by a square range, the area is searched over a circular range or a square range with the reference position KP that will be described later as a center. In this case, the user inputs the numerical values by voice saying, for example, "a radius of 10 kilometers" or a square of a side of 10 kilometers". Then, the data of the radius or the data of the length of the side input by voice are stored in the RAM 4 as the data AS for designating the area.

0052It is further allowable that the user inputs the name of a particular city, town or village by voice, so that the area of the city, town or village is searched. The reduced scales of the map may be in two kinds of "wide" and "details". In this case, a wide area of the map picture is searched when the user pronounces "wide". Then, the data designating the wide area are stored in the RAM 4 as the data AS for designating the area. When the user pronounces "details", the detailed area of the map picture is searched. Then, the data designating the detailed area are stored in the RAM 4 as the data AS for designating the area.

0053The above-mentioned genre of objective places and the area to be searched serve as a main reference for search. At a next step 124, a sub-reference specific to each genre of objective places is input. In this processing, a command signal is sent from the CPU 2 to the voice processor 11. Then, the speaker 13 generates the voice requesting a sub-reference that corresponds to the genre code number JC that is designated above. When the designated genre pertains to "gas stations", the voice is sounded saying, for example, "What is the name?" When the designated genre pertains to "restaurants", the voice is sounded saying, for example, "What kind of dish will you have?"

0054When a predetermined voice signal is input during a predetermined standby period, the voice data that are input are converted into sub-reference data KS by the CPU 2 and are stored in the RAM 4. When it is not needed to be selected the sub-reference by the user, the CPU 2 automatically stores the sub-reference data KS that have been determined in advance in the RAM 4. When the genre pertains to parking zones, the sub-reference data KS representing "parking zones" are stored. The items of the sub-reference are the same as the items included in the objective place data MD stored in the objective place data file F16.

0055When the operation by voice is not carried out, the user manipulates the keys on the touch panel 34. Then, a menu of the areas to be searched is shown on the display 33. The user selects an area to be searched out of the menu. Then, a menu of sub-references is shown on the display 33. The user selects at least one sub-reference out of the menu.

9. Processing for Determining Reference Position (First Embodiment)

0056Fig. 8 is a flow chart illustrating a processing for determining a reference position (step 104). First, a command signal is sent from the CPU 2 to the voice processor 11, and the speaker 13 sounds the voice saying, for example, " Designate a reference position, please". Then, the user inputs by voice a reference point before the predetermined standby period elapses. The reference position may be the present position, final goal, passing place, center of the map picture shown on the display 33, intersection on the guide route or a position of a building.

0057When the voice is input by the user, the CPU 2 analyzes the content of the voice input data. When the reference position is remote from the present position, the designated point is stored in the RAM 4 as the reference position data KP (step 148). For instance, when the final goal is the reference position (step 134), the goal data TP is read out and is stored as reference position data KP.

0058When a passing point or a point on the route is designated (steps 136, 140), the user inputs by voice the name of that point. Then, the CPU 2 searches a point of the same name as the one that is input by voice from the intersection data file F2 and the goal data file F6. The position data of the point that is found is stored as the reference position data KP. When the center of the map is designated (step 138), the position data of coordinates at the center of the map picture shown on the display 33 are stored as the reference position data KP. The points other than those mentioned above may be designated as reference positions.

0059When the present position is designated (step 132) or when no voice is input within the above-mentioned predetermined standby period (step 130), a processing of a step 142 is executed. In step 142, a reference position is automatically set based upon the data related to the roads. When the reference position that is automatically set is the present position (step 144), the reference position is corrected depending upon the running speed (step 146). The above-mentioned inputs may be introduced by using keys on the touch panel instead of using voice.

10. Processing for Automatic Setting (First Embodiment)

0060Fig. 9 is a flow chart illustrating a processing for automatically setting the reference position (step 142). First, the CPU 2 reads the data MP related to the present position from the RAM 4 (step 150). Based upon the data MP related to the present position, the road data file F4 is searched and the data related to the road on which the car is running is obtained (step 152). The data related to the roads may also be obtained from the data PI related to the present position stored in the RAM 4. The obtained data RD related to the roads are stored in the RAM 4. The data RD related to the roads is "01" when the road on which the car is running is an expressway, is "10" when the road on which the car is running is an elevated road or a tunnel, and is "00" when the road on which the car is running pertains to none of the above.

0061When the car is running on the expressway, for example, the user is not allowed to reach the objective places other than service areas unless he gets off to a highway. Therefore, when the present position is designated by the user as a reference position while the car is running on the expressway, a point at which the car gets off to a highway is set to be a reference position. In this case, an interchange at where the car is to get off is searched from the map data file F1, and the position of this interchange is stored in the RAM 4 as a reference position data KP (step 156).

0062When the road on which the car is running is an elevated road or a tunnel, the car is allowed to turn neither to the right nor to the left at the present position. Therefore, an intersection that appears first is searched from the intersection data file F2, and the position of this intersection is stored as a reference position data KP (step 160). When the car is running on a highway and this highway is neither an elevated road nor a tunnel, the present position data MP is regarded to be a reference position data KP. The present position data MP is corrected by a processing for correcting the reference position (step 146).

11. Processing for Correcting the Reference Position (First Embodiment)

0063Fig. 10 is a flow chart illustrating the processing for correcting the reference position (step 146). It is not possible to suddenly turn the car to the right or to the left at the present position. When the present position is a reference position, therefore, the reference position is corrected to be ahead of the present position depending upon the running speed data V. The CPU 2 detects the running speed data V based upon the clock signals from the timekeeping device 6 and the data ML related to the traveled distance from the distance sensor 23 (step 170). The running speed may be obtained from the running speed data output from a speedometer (not shown).

0064The CPU 2 determines the correction distance data AL depending upon the running speed data V that is detected (step 172). The correction distance data AL is determined by executing a predetermined operation or by being read out from a memory table in which correction distance data AL corresponding to running speed data V are stored. The correction distance data AL increases with an increase in the running speed data V. Next, the CPU 2 reads the data MP related to the present position from the RAM 4 (step 174), and a position which is ahead of the present position by the correction distance data AL is regarded to be a reference position (step 176). The corrected position is stored in the RAM 4 as data KP related to the reference position.

12. Processing for Searching Objective Places (First Embodiment)

0065Fig. 11 is a flow chart of a processing for searching the objective places (step 106). When the radius or the length of the side of the area to be searched is designated by the user (step 180) in the processing for determining the reference for search (step 102), the CPU 2 reads the reference position data KP and the area designation data AS (step 182). Then, a circle of the radius input by the user or a square having a side of the length input by the user is set with the reference position as a center, and the area surrounded by the circle or the square is regarded to be a area to be searched (step 184). The area data KA to be searched is stored in the RAM 4 as the coordinate data of a circle or a square with the reference position KP as a center.

0066When a "wide", "details" or a reduced scale is designated by the user in the processing for determining the reference for search (step 102), the CPU 2 discriminates the content of the area designation data AS (step 186) and, then, reads the data KP related to the reference position (step 188). Then, the center of a map picture of the designated scale is brought into agreement with the reference position KP. The area of the map picture is stored in the RAM 4 as the area data KA to be searched (step 190).

0067When the area data KA to be searched is set, the CPU 2, then, reads the genre code number data JC (step 192). Then, objective place data of a genre in agreement with the genre code number data JC are read out from the objective place data file F16. The coordinate data in the objective place data that are read out are searched and, hence, the objective places are searched in the area KA to be searched (step 194). The name data MM of the searched objective places, phone number data MT, coordinate data MZ, and information data MD are read out and are stored in the RAM 4 as data KM related to objective places to be searched. Thus, the objective places are searched from the objective place data file F16. On the other hand, the final goal and the passing places are searched from the goal data file F6.

13. Processing for Determining the Order of Priority (First Embodiment)

0068Fig. 12 is a flow chart illustrating a processing for determining the order of priority (step 108). First, the CPU 2 reads the data MP related to the present position (step 200). Furthermore, coordinate data MZ related to the objective places to be searched are read out from the data KM related to objective places to be searched (step 202). The distances are then calculated from the present position to the objective places to be searched (step 204). The distances found through this calculation are stored in the RAM 4 as data TK related to the distances to the objective places (step 204). The distances TK to the objective places are straight distances found according to Pythagorean theorem or full lengths of the routes to the objective places being searched which are found from the map data file F1. The routes may be the shortest ones or those determined depending upon the data related to the roads.

0069Next, the CPU 2 reads the sub-reference data KS (step 206). The distances TK to the objective places are weighted or unnecessary data in the data KM related to the objective places to be searched are erased depending upon the sub-reference data KS (step 208). The order of priority is determined depending upon the weighted distances TK to the objective places or depending upon the data KM related to the remaining objective places to be searched (step 210). The data UN related to the order of priority are stored in the RAM 4.

14. Processing for Changing Distances to Objective Places (First Embodiment)

0070Figs. 13 and 14 illustrate a flow chart of a processing for weighting the distances TK to the objective places and for erasing undesired data KM related to objective places to be searched (step 208). First, the CPU 2 discriminates the contents of sub-reference data KS (steps 220, 250, 260, ---).

0071When, for instance, the data indicating the "direction" are included in the sub-reference data KS, it is discriminated whether the reference position data KP represent the present position or not (step 222). When the reference position is the present position, angles are calculated between the direction of progress of the car and the objective places to be searched (step 224). These angles are stored in the RAM 4 as data θ related to the directions of objective places. The directions θ of objective places are calculated as described below. First, the CPU 2 reads the data θ 1 related to the angle of relative direction from the RAM 4.

0072The angle θ 1 of the relative direction is the one subtended by the direction of progress of the car with respect to the north direction, and is expressed by a value of 0 to 180 degrees in the counterclockwise direction from the north direction and by a value of 0 to -180 degrees in the clockwise direction from the north. The CPU 2 further reads the present position data MP and the coordinate data MZ related to objective places to be searched from the RAM 4. Then, tanθ 2 is calculated from the coordinate data MZ and the present position data MP. From the tanθ 2, the CPU 2 further calculates an angle θ 2 of relative direction of the objective place to be searched with respect to the north direction. The angle θ 2 of relative direction of the objective place to be searched is stored in the RAM 4 as data θ 2 related to angles of objective places.

0073The direction θ of the objective place is calculated according to θ = θ 2 - θ 1. The direction θ of the objective place is further calculated depending upon,<maths id="math0001" num=""><math display="block"><mrow><mtext>when θ > 180 degrees: θ = θ - 360 degrees,</mtext></mrow></math><img file="EP0720003B1_D0001.tif" /></maths> and<maths id="math0002" num=""><math display="block"><mrow><mtext>when θ < -180 degrees: θ = 360 degrees + θ .</mtext></mrow></math><img file="EP0720003B1_D0002.tif" /></maths>

0074Due to this calculation, the direction of the car is discriminated with respect to the objective places to be searched. The direction is discriminated on the following basis:<maths id="math0003" num=""><math display="block"><mrow><mtext>Front left direction when 0 ≦ θ ≦ 90,</mtext></mrow></math><img file="EP0720003B1_D0003.tif" /></maths><maths id="math0004" num=""><math display="block"><mrow><mtext>Front right direction when -90 ≦ θ &lt; 0,</mtext></mrow></math><img file="EP0720003B1_D0004.tif" /></maths><maths id="math0005" num=""><math display="block"><mrow><mtext>Back left direction when 90 &lt; θ ≦ 180,</mtext></mrow></math><img file="EP0720003B1_D0005.tif" /></maths> and<maths id="math0006" num=""><math display="block"><mrow><mtext>Back right direction when -180 ≦ θ &lt; -90.</mtext></mrow></math><img file="EP0720003B1_D0006.tif" /></maths>

0075The result of discrimination is added as a flag to the data KM related to the objective places to be searched. When the direction of the objective place is, for instance, "front left direction", the flag is "01". When the direction of the objective place is "front right direction", the flag is "10". When the direction of the objective place is "back left direction" or "back right direction", the flag is "11".

0076Next, when the direction of the objective place is "front left direction", the distance TK to the objective place is multiplied by "1". The distance TK to the objective place that is multiplied is stored in the RAM 4 as a new distance TK to the objective place (step 230). When the direction of the objective place is "front right direction", the distance TK to the objective place is multiplied by "1.5". The distance TK to the objective place that is multiplied is stored in the RAM 4 as a new distance TK to the objective place (step 234). When the direction of the objective place is "back left direction" or "back right direction", the distance TK to the object place is multiplied by "2". The distance TK to the objective place that is multiplied is stored in the RAM 4 as a new distance TK to the objective place (step 238).

0077In a country where the rule is keep to the left, easiness to drive the car decreases in the order of toward the "front left direction", front right direction" and "back direction". Therefore, the weighting is so effected that the distance to the objective place is shortened in a direction in which the car can be driven most easily. The above-mentioned calculation of direction and weighting (steps 222 to 238) are executed for all of the objective places KM to be searched (step 240).

0078When the reference position is not the present position, the reference position data KP are used instead of the present position to execute the above-mentioned processing. Thus, the direction of the objective place is found with respect to the car at the reference position. The distance TK to the objective place is weighted depending upon the direction of the objective place. The angle θ 1 of direction of the car at the reference position is an angle of the direction of progress of a guide route at the reference position with respect to the north direction. This angle is calculated using the data in the road data file F3.

0079When the designated genre pertains to "parking", the data representing "parking" are included in the sub-reference data KS. When the sub-reference data KS read by the CPU 2 includes the data of "parking", the " data related to no vacancy" are read out as shown in Fig. 14 (step 252). The data related to no vacancy are picked up from the data related to the roads such as VICS data VD or the ATIS data AD, etc. The data related to no vacancy are added as a flag to the data KM related to objective places to be searched. The CPU 2 erases the data KM related to objective places to be searched to which is added the flag of "data of no vacancy". Thus, the parking zones without vacancy are excluded from the objective places.

0080Next, the data related to the number of cars that can be accommodated are read out from the data KM related to remaining objective places to be searched. The distances TK to the objective places to be searched are weighted depending upon the numbers of cars that can be accommodated. For instance, when the number of cars that can be accommodated is smaller than 50, the distance TK to the objective place is multiplied by "2". When the number of cars that can be accommodated is from 50 to 99, the distances TK to the objective places is multiplied by "1.5". When the number of cars that can be accommodated is not smaller than 100, the distances TK to the objective places is multiplied by "1". Thus, the weighting is effected in a manner that the larger the number of cars that can be accommodated, the smaller the distances TK to the objective places.

0081When the designated genre pertains to "gas stations", "convenience stores" and the like, the sub-reference data KS includes the "name" data related to the supplier companies, chain stores, etc. In this case, the CPU 2 discriminates whether the name codes in the data KM related to the remaining objective places to be searched are in agreement with the name codes of the sub-reference KS. The data KM related to objective places of names different from the names of the sub-reference KS are erased (step 262). Thus, the objective places of names other than those designated by the user are excluded.

0082Though neither diagrammed nor described, the sub-references KS may further include, for example, "upper limits and lower limits" such as of direction, distance, fees, etc., "designated ranges" such as urban areas, rural areas, numbers of cars that can be accommodated, business times, etc., "selective designations" of specific objective places, "exceptional designations" of specific objective places, "fees", "positions" such as near a pond, close to a port, etc., "altitudes" such as on the mountains or on the rooftop, "depths" such as under the sea level or under the ground, "size", "attribute", "features", "contents", "natures", etc. The distances TK to the objective places are weighted and undesired data KM related to objective places to be searched are erased depending upon these sub-references KS.

0083In addition to the above-mentioned information data related to the roads, the distances TK to the objective places are weighted or undesired data KM related to the objective places to be searched are erased based upon information of the routes to the objective places such as information of-the area where objective places exist, construction that is taking place, controlled traffic, steep slopes, etc.

15. Processing for Determining the Order of Priority (First Embodiment)

0084Fig. 15 is a flow chart illustrating a processing for determining the order of priority (step 210). First, the CPU 2 reads the data KM related to the remaining objective places to be searched, and reads the data TK related to the distances to the remaining objective places KM to be searched (step 270). The data TK related to the distances to the objective places that are read out are arranged in an increasing order (step 272). The order of priority is determined in the order of increasing distances TK to the objective places (step 274). The data UN related to the order of priority are stored in the RAM 4 being corresponded to the data KM related to the objective places to be searched.

16. Processing for Indicating Objective Places (First Embodiment)

0085Fig. 16 is a flow chart illustrating the processing for indicating objective places (step 110). First, the CPU 2 reads the data KM related to the remaining objective places to be searched and the data UN related to the order of priority (step 280). A command is sent from the CPU 2 to the image processor 9, and the image data of a map with the reference position KP as a center are read out from the image memory 10. The map picture has a reduced scale as designated by the user.

0086To the image data that are read out are added marks of objective places to be searched, their names and the order of priority. The image data are sent to the display 33, and a map picture is shown (step 282). As shown in, for example, Fig. 17, the names of objective places and numerals 63 to 65 representing the order of priority are indicated on the map picture together with marks 60 to 62 of objective places. In an example shown in Fig. 17, the names and the order of priority are given to only those objective places of which the orders of priority are from first to third places.

0087When a character "LIST" on the picture is touched by a finger by the user, as shown in Fig. 18, the display 33 shows a list of contents such as names, phone numbers, ranks of the shops, etc. of objective places KM to be searched together with the order of priority (steps 284, 286). When the characters "RETURN" 67 on the picture is touched by the finger, the map picture of Fig. 17 is shown. This list can be printed by using a printer 35.

0088The user selects one of the objective places and touches by finger any one of the objective place marks 60 to 62 in Fig. 17, the order of priority of Fig. 18 (numeral at the left end) or the name (step 288). Then, the position of the selected objective place comes to the center of the picture (step 290). The map picture is hereinafter referred to as a picture for setting objective places. If, for example, "AAA" is selected in Fig. 17 or 18, a mark 60 of "AAA" is moved to the center of the picture as shown in Fig. 19, and the name 68 is indicated at an upper portion of the picture. When the character "RETURN" 67 is touched, the picture of Fig. 17 is shown. When the character "SET" 72 is touched (step 292), the place "AAA" is stored in the RAM 4 as the objective place (step 112 of Fig. 6).

0089When the character "CHANGE THE POSITION" 71 is touched (step 294), a cursor 69 and arrows 70 are indicated on the display 33 as shown in Fig. 19 (step 296). The cursor 69 is a small circle surrounding the center of the picture, and the arrows 70 are arranged to indicate eight directions surrounding the cursor 69. On this picture, the objective place indicated at the center of the picture can be changed into a different objective place. When the user touches any arrow 70, the picture is scrolled in the direction of the arrow 70 that is touched (step 296).

0090The user scrolls the screen and brings the mark of any desired objective place into the cursor.69. For instance, when the user wishes a mark 73 in Fig. 19, the picture is scrolled by the user as shown in Fig. 20, and the user brings the mark 73 into the cursor 69. A new objective place is not limited by the genre designated by the user but can be freely selected from the points shown on the display 33.

0091When the any arrow 70 is not touched within a standby period, the arrows 70 are erased. Then, the picture for setting objective places indicates the character "CHANGE THE POSITION" 71 and the character "SET" 72. When the character "CHANGE THE POSITION" 72 on the picture is touched, the arrows 70 are indicated again, so that the picture can be scrolled (step 292).

17. Processing for Storing Objective Places (First Embodiment)

0092Fig. 21 is a flow chart illustrating a processing for storing objective places (step 112). When the character "SET" 72 is touched on the picture for setting objective places, the CPU 2 transfers the initial goal data TP set by the processing for setting the goals to a keeping area MK in the RAM 4 (step 300). Thus, the data related to the initial goal are preserved. The initial goal data TP are those of the final goal and passing places, and have been set by the processing for setting the goal (step 51 of Fig. 5) before the departure.

0093Next, the CPU 2 reads the coordinate at the center of the picture (step 302). The data related to objective place on the coordinate is searched from the objective place data file F16 (step 304). The data of objective place is stored in the RAM 4 as new goal data TP (step 306). Thus, the objective place turn into new goal. The center of the picture on the display 33 is returned back to the present position. Then, the processing for searching the route to the objective places (step 52) and the processing for indicating the guide (step 53) are executed. Thus, the guide route is indicated to the objective places, and the navigation to the objective place that is designated by him is carried out. As the car arrives at the objective place, the initial goal data that had been kept are returned back again to the goal data TP. Thus, the navigation to the initial goal is carried out again.

0094The initial goal data that had been kept may be set to the goal data TP when the operation is executed by the user to restore the goal. Furthermore, the objective places may be set as passing places in a way to the initial goal, and the route to the initial goal via these objective places may be used as a new guide route.

0095According to the navigation device of this embodiment as described above, the objective places can be selected through a simple operation when the user suddenly wish to drop in a place in his way to the initially set goal. When a plurality of objective places are selected, furthermore, the objective places that conform the desire of the user are automatically determined in the order of priority based upon the references designated by the user or upon the references that are automatically set. The order of priority is indicated in a form that can be easily discerned by the user. Therefore, the user is allowed to determine the objective places within short periods of time.

0096The data related to the reference positions or to the reference for search are input through an input means such as voice, touch panel or switches. Therefore, the objective places conforming the desire of the user can be limited depending upon the positions or the contents. It is further possible to execute the operation by the voice input. Therefore, it is possible to execute the operation while driving the car.

0097The reference position is changed depending upon the running condition of the car (steps 104, 142, 146). For example, when the car is running fast, the reference position is set to be well ahead. When the car is running on an expressway, an interchange where the car is going to get off serves as the reference position. Moreover, the reference position is set at the present position or at a position remote from the present position (step 104), so that objective places at positions conforming the desire of the user can be searched.

0098Further, the reference for search is not fixed. Therefore, it is possible to change the reference for search depending upon the genre of objective places. Depending upon the desire of the user, furthermore, the reference for search can be changed (step 102). Thus, the data of objective places that conform the desire of the user are offered. The order of priority is determined depending upon the geographical data of the objective places and the data related to the contents of the objective places.

0099Moreover, the objective place data file F16 stores data of a variety of items. Thus, a variety of references for search are set depending upon a wide variety of demand of the user. Moreover, external data such as VICS or ATIS are received, and the order of priority of objective places is determined based upon the external data (steps 208, 252). Accordingly, the data related to no vacancy of the parking zone, traffic jam of the roads, etc. can be received on time.

18. Second Embodiment

0100According to the second embodiment, the objective places are searched depending upon the reference for search. Then, the reduced scale of the map is automatically adjusted when the searched objective places are indicated on the display 33. In the second embodiment, the following processings are carried out in the aforementioned whole processing.

19. Processing for Setting Objective Places (Second Embodiment)

0101Fig. 22 is a flow chart of a processing for setting objective places (step 400) executed in the processing for setting the goals (step 51). After the final goal and passing places are set, the objective places are set by another operation.

0102This processing starts when the operation for setting the objective places is requested by the operation of the change-over switch 42. Moreover, the operation for setting the objective places is often carried out while driving the car. When an instruction is issued to start this processing, therefore, the voice operation mode is automatically set. When the change-over switch 41 is operated to request the manual operation mode, the operation for setting the objective places is manually carried out by using the operation switch 40. This processing may be executed in response to an instruction by voice. This eliminates the need to operate the change-over switches 41, 42.

0103The processing for setting objective places (step 400) is repetitively executed together with the processing for obtaining the present position (step 50), processing for searching the route (step 52) and processing for indicating the guide (step 53). When the car has approached an intersection or a branching point while the operation is being carried out to set the objective places, the operation for setting the objective places is interrupted for several seconds. During this period, the intersection or the like may be guided by voice and indication.

0104In the processing for setting the objective places (step 400), a processing for determining a reference for searching objective places (step 402), a processing for searching the objective places depending upon the reference for search (step 404), a processing for indicating the objective places that are searched (step 406), and a processing for storing one of the objective places selected by the user (step 408) are successively executed.

20. Processing for Determining Reference for Search (Second Embodiment)

0105Fig. 23 is a flow chart of a processing for determining reference for search (step 402). At a step 420, an command signal is sent to the voice processor 11 from the CPU 2, and the speaker 13 sounds an inquiry saying, for example, "Which genre is it ?" The genre defines a range of content and serves as a first reference for search.

0106At a next step 422, it is discriminated whether a voice signal is input to the audio recognition unit 38 from the CPU 2 or not during a predetermined standby period. The voice signal that is input is converted into code data. The code data is collated with the genre code numbers JC in the objective place data file F16 (step 424). The genre code number data JC in agreement with the voice input are stored in the RAM 4. When the user pronounces, for example, a "gas station", the genre code number data JC of gas stations is stored in the RAM 4.

0107When the operation by voice is not carried out, the user operates keys on the touch panel 34, so that a genre menu is indicated on the display 33. The user then selects a genre out of the genre menu. 21. Processing for Searching Objective Places (Second Embodiment)

0108Fig. 24 is a flow chart of the processing for searching objective places (step 404). First, the CPU 2 reads the data MP related to the present position (step 430). The area to be searched is then set (step 432). The center of the area to be searched is the present position. The area to be searched defines a geographical range and serves as a second reference for search. The area to be searched is a range of predetermined coordinates of longitude and latitude. For instance, the present position is at the center in a square range having a side of a predetermined distance 2a. When the coordinates of longitude and latitude of the present position are (X, Y), the area to be searched covers a range of from X-a to X+a and from Y-a to Y+a. The distance 2a has been determined in advance. Therefore, the range of the area to be searched is equal to, or slightly narrower than, the range of the picture when a map having the smallest scale of 1 to 640,000 is shown on the display 33. The coordinates of the area to be searched are stored in the RAM 4 as area data KA to be searched.

0109Next, the genre code number data JC is read (step 434). Then, the data of objective places of a genre in agreement with the genre code number JC are read from the objective place data file F16. It is then discriminated whether the coordinate data MZ in the data of objective places that are read out lie within the above-mentioned area KA to be searched or not (step 436). When the coordinates of longitude and latitude of objective places are (Xp, Yp), it is discriminated at the step 436 whether there hold relations X-a &lt; Xp &lt; X+a and Y-a &lt; Yp &lt; Y+a. Not only the objective places present along the guide route is searched but also the objective places at points other than along the guide route is searched.

0110It is then discriminated whether a number of the objective places that are searched is larger than a predetermined number Z or not (step 437). When the number of the objective places is larger than the predetermined number Z, the name data MM of objective places in the area to be searched, phone number data MT of them, coordinate data MZ of them, and information data MD of them are read out and are stored in the RAM 4 as data KM related to the objective places to be searched (step 438). Symbol n represents a number of objective places in the area to be searched. When the number of objective places in the area to be searched is smaller than the predetermined number Z, this fact is informed by error indication and voice (step 439). In this case, the area KA to be searched may be expanded, and then the objective places are searched again from the expanded area KA. The area KA to be searched is stepwisely expanded until the number of objective places in the area KA to be searched becomes greater than the predetermined number Z.

22. Processing for Indicating Objective Places (Second Embodiment)

0111Fig. 25 is a flow chart of the processing for indicating the objective places (step 406). First, the CPU 2 reads the data MP related to the present position from the RAM 4 or the image memory 10 (step 440). The data MP related to the present position are coordinates (X0, Y0) of the present position in the map picture shown on the display 33 when this processing (step 406) is started. Next, the coordinate data (Xn, Yn) corresponding to the scale of the map are read out (step 442) from the coordinate data of n object places KM to be searched stored in the RAM 4 at the above-mentioned step 438.

0112The coordinate data are those of coordinates on the scale of map shown on the display 33 when the processing (step 406) is started. Coordinate differences (Xna, Yna) are then calculated between the coordinates (X0, Y0) of the present position and the coordinates (Xn, Yn) of the objective places (step 444). This calculation complies with Xna = | Xn - X0|, Yna = | Yn - Y0|, and is executed for all coordinates (X1, Y1), ---, (Xn, Yn) of n objective places to be searched. The coordinate differences vary in proportion to straight distances between the present position and the objective places to be searched. The data of coordinate differences (Xna, Yna) are stored in the RAM 4.

0113Next, a processing (step 446) for adjusting the reduced scale adjusts the scale of the map picture on which the objective places to be searched are indicated based on the coordinate differences (Xna, Yna). For example, a reduced scale is selected for indicating the predetermined number Z of objective places to be searched in the order of increasing distance from the present position. Then, marks, figures or characters representing the objective places to be searched are indicated on the display 33.

23. Processing for Adjusting the Reduced Scale (Second Embodiment)

0114Fig. 26 is a flow chart of a processing for adjusting the reduced scale (step 446). In this processing, the scale is stepwisely reduced from the most detailed map, i.e., from the greatest scale. A reduced scale is selected to indicate more number of the objective places to be searched than the predetermined number Z. In the following description, Z is 3. The value Z has been stored in the ROM 3 or 5 in advance. The value Z is not limited to 3, as a matter of course.

0115In the processing shown in Fig. 26, the CPU 2, first, reads the map data of the most detailed scale of 1 to 10,000 (step 450). The data (Xna, Yna) of the above-mentioned n coordinate differences are converted into coordinates on the coordinate system of the map data (step 452). The data (Xna, Yna) of coordinate differences are those of coordinate differences on the map that had been indicated when the processing for indicating the objective places (step 406) was started. Therefore, the data of coordinate differences must be. converted according to the reduced scale of 1 to 10,000. When the scale of the map is K times, the data (Xnr, Ynr) of coordinate differences after the conversion become (Xna, Yna)/K. The conversion processing is executed for all data of coordinate differences (X1a, Y1a), ---, (Xna, Yna) of n objective places to be searched.

0116Next, a map picture of the reduced scale of 1 to 10,000 is set with the present position as a center. It is then discriminated whether there are not less than three data (Xna, Yna) of coordinate differences (step 454). Referring to Fig. 27, the picture of a frame is shown on the display 33, the center of the picture being the present position (X0, Y0). The length of coordinates in the X-direction from the center of the picture to an end of the picture is denoted by XMAX, and the length of coordinates in the Y-direction from the center of the picture to an end of the picture is denoted by YMAX. XMAX and YMAX have been calculated in advance for the map of each scale and have been stored in the ROM 3 or 5. It is discriminated whether the relations Xnr ≦ XMAX and Ynr ≦ YMAX hold or not for the data (X1r, Y1r), ---, (Xnr, Ynr) of coordinate differences. The objective places satisfying these conditions are indicated on the picture. It is further discriminated whether there are not less than three objective places satisfying these conditions.

0117When the result of discrimination at the step 454 is no, the CPU 2 reads the map data of a scale of 1 to 20,000 which is wider by one step (step 456). The data (X1r, Y1r), ---, (Xnr, Ynr) of coordinate differences are converted into coordinate differences on the map of the scale of 1 to 20,000 (step 452). It is then discriminated whether the relations Xnr ≦ XMAX and Ynr ≦ YMAX hold or not for the data (X1r, Y1r), ---, (Xnr, Ynr) of all coordinate differences. It is further discriminated whether there are not less than three objective places satisfying these conditions (step 454). Similarly, hereinafter, the reduced scale of the map is shifted toward the wider side step by step until not less than three objective places are included in the picture on the display 33. When there are not less than three objective places on the picture, the result of discrimination at the step 454 becomes yes. Then, the objective places satisfying the conditions Xnr ≦ XMAX and Ynr ≦ YMAX are indicated on the display 33 as the objective places to be searched (step 448 of Fig. 25).

0118When the result of the step 454 becomes yes, the map of a reduced scale at this moment is shown on the display 33. The center of picture at this moment is the present position (X0, Y0). The objective places to be searched are indicated on the picture. Referring, for example, to Fig. 28, marks 80 to 82 representing not less than three objective places are indicated on the display 33. Near the marks 80 to 82 representing the objective places, names 83 to 85 of the objective places are indicated. The names 83 to 85 are further attached the numerals in an increasing order of distance from the present position (X0, Y0).

0119The above-mentioned area to be searched is within a range of picture of the smallest scale (step 432 of Fig. 24), and not less than three objective places have been confirmed at the step 437 of Fig. 24. Therefore, the steps 452, 454 and 456 are repeated and when the map of the smallest scale is finally shown, not less than three objective places are necessarily indicated.

24. Processing for Storing Objective Places (Second Embodiment)

0120Fig. 29 is a flow chart of a processing for storing the objective places (step 408). After the objective places to be searched are indicated on the display 33, the processing for storing the objective places (step 408) is started. Referring to Fig. 28, for instance, the user touches one of the marks 80 to 82 of the objective places (step 460), or the user inputs by voice one of the numerals attached to the names 83 to 85 of the objective places (step 462). Thus, a place to drop in is determined.

0121When there is a touch input or a voice input within a predetermined standby period, the data SP of the selected objective place are stored in the RAM 4 (step 464). The CPU 2 transfers the data TP of the initial goals <i>set</i> by the processing for setting the goals to a keeping area MK in the RAM 4 (step 466). Thus, the data related to the initial goals are preserved. The data TP of the initial goals are those of the final goal and the passing places, and have been set by the processing for setting the goals (step 51 of Fig. 5) before the departure. Then, the data SP related to the objective place is stored in the RAM 4 as the data TP of a new goal (step 468). Thus, the objective places turn into new goals. The center of picture of the display 33 is returned back to the present position.

0122Then, the processing for searching routes to the goals (step 52) and the processing for indicating the guide (step 53) are executed. Thus, the guide route is indicated up to the objective place, and the navigation to the objective place that is designated by user is carried out. When the car arrives at the objective place, the data of the initial goals that had been kept are returned back again to the data TP of the goals. Then, the navigation is executed again up to the goals.

0123When the present position is moved by more than a predetermined distance during the standby period for input at the step 460 or 462, or when a predetermined period of time has lapsed, the processing 446 is executed to adjust the reduced scale. Therefore, when the number of objective places indicated on the display 33 decreases accompanying the motion of the car, the reduced scale is adjusted so that there are indicated not less than three objective places.

0124The data of the initial goals that had been kept may be set to the data TP of the goals when the user executes the operation to restore the goals. Moreover, the objective places may be set as passing places in the way to the initial goal, and the route that leads to the initial goal via this objective place may be used as a new guide route.

25. Third Embodiment

0125According to a third embodiment, a processing (step 446) shown in Fig. 30 is executed instead of the processing for adjusting the reduced scale (step 446) of the second embodiment. The constitution and processings of the third embodiment, except the above processing, are the same as those of the second embodiment. Fig. 30 illustrates a flow chart of the processing for adjusting the reduced scale (step 446) according to the third embodiment. In Fig. 30, the same steps as those of the processings of Fig. 26 are denoted by the same reference numerals.

0126In this processing, a step 470 is executed instead of the step 450 of Fig. 26. At step 470, the map data shown on the display 33 are read out. The map is the one that is shown when the processing for indicating the objective places (step 406) is started. Therefore, the scale of the map picture shown on the display 33 is stepwisely decreased until not less than three objective places are indicated.

0127In the processing of Fig. 26, the map is stepwisely shifted from the greatest scale toward the smaller scales. Therefore, the scale of the map that is shown often becomes greater than the scale of before the processing for setting the objective places is started. According to the processing shown in Fig. 30, on the other hand, the scale of the map that is shown does not become larger than the scale of before the processing for setting the objective places is started.

26. Fourth Embodiment

0128According to a fourth embodiment, a processing (step 446) shown in Fig. 31 is executed instead of the processing for adjusting the reduced scale (step 446) of the second embodiment. The constitution and processings of the fourth embodiment, except the above processing, are the same as those of the second embodiment. Fig. 31 illustrates a flow chart of the processing for adjusting the reduced scale (step 446) according to the fourth embodiment. In Fig. 31, the same steps as those of the processings of Figs. 26 and 30 are denoted by the same reference numerals.

0129In this processing, a step 472 is inserted before the step 454 of Fig. 30. The step 472 discriminates whether there are coordinate data (Xna, Yna) of not smaller than three objective places in a small area 90 shown in Fig. 32. The CPU 2 reads the map data at the steps 470, 474 and 456. Then, the map is shown on the display 33, and the present position is brought to the center. The small area 90 is shown on the picture.

0130The length of coordinates in the X-direction from the center of the picture to an end of the small area 90 is denoted by XMIN, and the length of coordinates in the Y-direction from the center of the picture to an end of the small area 90 is denoted by YMIN. XMIN and YMIN have been calculated in advance for each of the reduced scales, and have been stored in the ROM 3 or 5. Here, however, the small area 90 is not provided in the map of the largest scale of 1 to 10,000. When the reduced scale is increased by one step, an area 91 shown in Fig. 32 is indicated on the picture. The small area 90 is equal to, or is slightly narrower than, the area 91.

0131The step 472 then discriminates whether the relations Xnr ≦ XMIN and Ynr ≦ YMIN hold or not for the data (X1r, Y1r), ---, (Xnr, Ynr) of all coordinate differences. It is further discriminated whether there are not smaller than three objective places satisfying these conditions. When the discriminated result of this step 472 is no, the CPU 2 reads the map data of a scale which is increased by one step (step 474). The scale of the map is stepwisely increased until the result of the step 472 becomes yes (step 474). Here, however, the small area 90 is not provided for the map of the smallest scale of 1 to 10,000. When the step 472 consecutively produces the discriminated result which is yes, therefore, the map of a reduced scale of 1 to 10,000 is finally shown.

0132When the discriminated result at the step 472 is no, on the other hand, the processings of steps 454 and 456 are executed. Therefore, the scale of the map is stepwisely decreased until there are indicated not smaller than three objective places to be searched. As described above, the small area 90 is equal to, or is slightly narrower than, the area 91. Therefore, the processings of the steps 472 → 474 → 452 → 472 → 454 → 456 → 452 → 472 → 474 → --- are not repeated.

0133When, for example, not smaller than three objective places to be searched are indicated, it often happens that not smaller than three objective places to be searched are densely located surrounding the present position. In this case, the map is enlarged so that the user is allowed to easily search the nearest objective place. When there are not smaller than three objective places to be searched within the small area 90, the objective places to be searched outside the small area 90 are not indicated. Usually, however, a place on where the user drop in is close to the present position. This embodiment therefore is reasonable.

27. Fifth Embodiment

0134According to a fifth embodiment, a processing (step 446) shown in Fig. 33 is executed instead of the processing for adjusting the reduced scale (step 446) of the second embodiment. The constitution and processings of the fifth embodiment, other than the above processing, are the same as those of the second embodiment. Fig. 33 illustrates a flow chart of the processing for adjusting the reduced scale (step 446) according to the fifth embodiment.

0135In this processing, the amounts of data (Xla, Yla), ---, (Xna, Yna) of n coordinate differences calculated at the above-mentioned step 444 are compared with each other. The greatest coordinate difference (Xka, Yka) is found among them and is stored in the RAM 4 (step 480). Based upon the maximum coordinate difference (Xka, Yka), an optimum reduced scale is selected from the memory table (step 482).

0136The maximum coordinate difference (Xka, Yka) is a value that corresponds to the reduced scale of when the processing for indicating the objective places to be searched (step 406) is started. At the step 482, the maximum coordinate difference is converted into a practical distance L between the present position and the objective place to be searched. The data of coordinate difference are converted into the length of a straight line according to Pythagorean theorem, and are divided by a reduced scale of the map that is shown. Thus, the distance L is found. The distance data L are stored in the RAM 4.

0137The ROM 3 or 5 stores a data table that is shown in Fig. 34. The data table contains the distances L between the present position and the objective place having a maximum coordinate difference, as well as a reduced scale of the map in a manner being corresponded to each other. Then, the step 482 determines the reduced scale relying upon the distance L found from the data table. The map data of this reduced scale are read by the CPU 2 and are sent to the image processor 9. As described earlier, the area KA to be searched defines the range of the map picture having the greatest scale (steps 432, 436). Therefore, the objective place having the maximum coordinate difference is indicated on the picture of at least the maximum scale.

0138According to this embodiment as described above, the reduced scale is not stepwisely adjusted but is determined by one time of selection based on the maximum coordinate difference. Therefore, the objective places to be searched are indicated within a short period of time after the start of the processing for setting objective places to be searched.

28. Sixth Embodiment

0139In the above-mentioned second to fifth embodiments, not less than three objective places to be searched are indicated on the display 33. The user, therefore, is allowed to compare the distances from the present position to the objective places to be searched. The user, however, is unable to obtain data related to the contents of the objective places. The contents of the objective places may not often meet the desire of the user. According to the sixth embodiment, therefore, the order of priority is imparted depending upon the contents of the objective places. The sixth embodiment.is a combination of the first embodiment with the second to fifth embodiments.

0140The whole circuit, data file, objective place data file, register and whole processing of the sixth embodiment are the same as those shown in Figs. 1 to 5. The sixth embodiment executes the processing for setting objective places (step 100) shown in Fig. 6, processing for determining the reference for search (step 102) shown in Fig. 7, processing for determining the reference position (step 104) shown in Fig. 8, processing for automatic setting (step 142) shown in Fig. 9, processing for correcting the reference position (step 146) shown in Fig. 10, processing for determining the order of priority (step 108) shown in Fig. 12, processing for changing the distances to the objective places (step 208) shown in Figs. 13 and 14, processing for determining the order of priority (step 210) shown in Fig. 15, and processing for storing objective places (step 112) shown in Fig. 21.

0141In this embodiment, steps 490, 492 and 494 shown in Fig. 35 are inserted after the step 194 of the processing for searching objective places (step 106) shown in Fig. 11. At the steps 180 to 190 of Fig. 11, the area KA to be searched that is designated by the user is stored in the RAM 4. Then, the genre code number data JC are read at the step 192. At the step 194, the objective places are searched that conforms the genre designated by the user.

0142At the step 490 shown in Fig. 35, it is discriminated whether there are not less than Z objective places to be searched. When there are not less than Z objective places to be searched, then, the name data MM of objective places in the area to be searched, phone number data MT, coordinate data MZ and information data MD are read out and are stored in the RAM 4 as data KM related to the objective places to be searched (step 492). When not less than Z objective places to be searched do not exist in the area to be searched, this fact is informed by error indication and voice (step 494).

0143According to this embodiment, the processing for indicating the objective places (step 406) of the second to fifth embodiments is executed in the processing for indicating the objective places (step 110 of Fig. 6), and in which is further executed any one of the processings for adjusting the reduced scale (step 446 of Figs. 26, 30, 31, 33) of the above-mentioned embodiments.

0144Accordingly, the reduced scale of the map is so adjusted as to indicate not less than three objective places to be searched. On the map picture, marks representing the objective places to be searched are indicated. Near the marks of the objective places, further, names of the objective places are indicated. Moreover, the order of priority is attached to the names of the objective places. By making reference to the order of priority, the user determines a place to drop in out of the objective places being searched. The user then performs the operation to set the objective places (step 112). Thus, the user is allowed to determine within a short period of time the objective place that conform the requirements desired by the user.

29. Seventh Embodiment

0145According to the above-mentioned sixth embodiment, the objective places having higher priorities but are remote from the reference position are not often indicated, but, instead, objective places having lower priorities and close to the reference position are often indicated. According to a seventh embodiment, therefore, objective places of a number of Z having higher priorities are picked up. The seventh embodiment executes a processing shown in Fig. 36 instead of the processing shown in Fig. 6. In this processing, steps 500 to 506 are inserted between the step 108 and the step 110 in the processing of Fig. 6.

0146At the step 108, the order of priority is determined. Then, the data UN related to the order of priority are read out from the RAM 4, and the amounts of the data UN related to the order of priority are compared. The objective places of a number of Z are searched in the order of decreasing priority (step 500). Distances are calculated up to Z objective places from the reference position (step 502). An objective place which is the remotest from the reference position is selected out of Z objective places (step 504). The distance to the remotest objective place is stored in the RAM 4 as the distance data L. A reduced scale of the map corresponding to the distance data L is found from the data table shown in Fig. 34 (step 506).

0147Next, the objective places of the number of Z are indicated on the map picture of the selected scale (step 110). The user selects an objective place by making reference to the order of priority (step 112). According to this embodiment as described above, the objective places of a number of Z are picked up in the order of decreasing priority, and the scale of the map is adjusted. Thus, the Z objective places that are picked up are indicated. Therefore, the objective places which have higher priorities but are remote from the reference position are even indicated.

30. Eighth Embodiment

0148According to the fifth embodiment, the range of the area to be searched is the one in which the map of the largest scale is shown on the display 33 (step 432 of Fig. 24). According to an eighth embodiment, on the other hand, the range of the area to be searched is not determined but the objective places that correspond to a designated genre are all searched. However, an objective place which is the remotest from the present position may not often be indicated in the map picture of the largest scale. When the distance L to the objective place remotest from the present position exceeds the range of the map picture of the largest scale of 1 to 640,000, therefore, a predetermined reduced scale is selected (lowermost column in Fig. 34). When the distance L is not less than 20000 meters, therefore, the reduced scale of the map is selected to be 1 to 80,000, and only those objective places included in the map picture of this scale are indicated.

31. Ninth Embodiment

0149A ninth embodiment executes a processing shown in Fig. 37 instead of the processing shown in Fig. 33. At a step 480, first, an objective place which is the remotest from the present position is selected. It is then discriminated whether the distance L to the remotest objective place is greater than the predetermined distance LMAX or not (step 510). When the table shown in Fig. 34 is used, the predetermined distance LMAX is 20000 meters. When the distance L is smaller than LMAX, a reduced scale corresponding to the distance L is found from the table of Fig. 34 (step 512). When the distance L is greater than LMAX, an objective place which is the second remotest from the present position is selected (step 514). It is then discriminated whether the distance L to the second remotest objective place is smaller than LMAX or not (step 510).

0150When the distance L to the second remotest objective place is greater than LMAX, then, the objective places which are the third, fourth, ---, remotest, are selected until there appears an objective place having a distance L smaller than LMAX. It is then discriminated whether the distance L to the selected objective place is greater than LMAX or not (steps 510, 514). When the distances to the objective places searched by the processing for searching objective places (step 404) are all greater than LMAX, an error message is informed (step 518).

32. Other Modified Embodiments

0151The present invention is in no way limited to the above-mentioned embodiments only but can be modified in a variety of other ways without departing from the scope of the invention as defined by the appended claims. For example, the processings of the steps 470, 452, 472, 454, 456 and 474 shown in Fig. 31 may be executed after the step 454 of Fig. 26 or after the step 454 of Fig. 30. There are thus indicated objective places to be searched in a number of not less than Z in the map picture. And the objective places to be searched are not densely located.

0152The processings of the steps 480 and 482 shown in Fig. 33 may be replaced by the step 456 or 474 of Fig. 26, 30 or 31. This makes it possible to indicate an objective place which is the remotest from the present position and to reduce the time for adjusting the reduced scale. In this case, the routine may be advanced to the processing next of the step 454 but not next of the step 452 after the processings of the steps 480 and 482.

0153The predetermined number Z may be any number other than 3 or may be 1. When Z = 1, only one objective place to be searched may be indicated on the display 33. When the result at the step 454 does not become yes even on the map of the smallest scale due to large number Z, an error message may be informed. Furthermore, when the result at the step 454 does not become yes even on the map of the smallest scale, the number Z may be decreased by a predetermined number until the result at the step 454 becomes yes. In this case, an error message is informed when Z becomes 0.

0154In the processing for searching the objective places (step 404) in the above-mentioned embodiments, furthermore, the Z objective places may be selected in the order of increasing distance from the present position or the reference position at a moment when the objective places are searched in the area being searched. Then, the Z objective places to be searched are indicated. A long period of time is consumed when the user selects an objective place out of many objective places to be searched of a number not less than Z. On the other hand, a short period of time is consumed when the user selects an objective place out of the Z objective places to be searched.

0155In the above-mentioned embodiments, furthermore, the area to be searched may not be set. In this case, when the objective places to be searched of a number not less than Z are not indicated on the map picture of the largest scale, an error message is informed. The area to be searched may be narrower than the range of the map picture of the largest scale. For example, the range of a predetermined distance from the present position or the reference position may be the area to be searched. Then, the range including the objective places to be searched is limited to the one which is close to the present position or the reference position. The range for selecting the reduced scales, however, becomes narrow. Moreover, the area to be searched may be set by the user.

0156The processing for determining the order of priority (step 108) may be executed after the processing for adjusting the reduced scale (step 446). Furthermore, the data related to coordinates (X0, Y0) of the present position, coordinates (Xn, Yn) of the objective place, XMAX, YMAX, etc. may be indicated on the coordinates of longitude and latitude. Further, the coordinate differences (Xna, Yna) and the distance L may be calculated using the coordinates of longitude and latitude.

0157When the sub-reference is not designated, the data MD related to the objective places may not be used. The map data file F1 may store map data of a plurality of reduced scales of not smaller than 7 or not larger than 7. Moreover, the map data may be expanded or contracted by the proportional calculation so as to obtain map data of different reduced scales. The map data may be thinned out when they are contracted. The proportional calculation or the thinning out of data is executed by the steps 456, 474 and 482. The reduced scale of the map may be varied continuously.

0158Moreover, a variety of data files shown in Fig. 2 may be stored in a programmable external storage medium such as floppy disk or the like. The sub-reference data KS is not limited to those items only that are stored in the objective place data MD in the objective place data file F16. For example, a desired item may be set in advance by the user, and the thus set item may be a sub-reference KS.

0159In the above-mentioned embodiments, the objective places are set. Here, however, the processing for adjusting the reduced scale may be executed and the processing for determining the order of priority may be executed even when the final goal and the passing places are set. In this case, when the goal is indicated on the map picture in the processing for setting the goal (step 51), the processing similar to the above-mentioned processing for setting the objective places (step 100) is executed.

0160After the step 404 or 406 of Fig. 22, furthermore, the processing for determining the order of priority (step 108) shown in Fig. 12 may be executed. In the second to fifth embodiment, therefore, the order of priority is imparted to the objective places to be searched.

0161When the objective places to be searched and the order of priority are indicated in the processing for indicating the objective places (step 110), furthermore, a picture of list shown in Fig. 18 may be displayed prior to the map picture of Fig. 17. The picture of list may be changed over to the map picture through a predetermined operation. The order of priority should be indicated in a manner of being easily recognized by the user when the map picture of Fig. 17 or the picture of list of Fig. 18 is being shown. For instance, color, brightness, luminous intensity, size and shape of the marks or names of the objective places are changed depending upon the order of priority, or the indications of them are flashed. This enables the user to visually obtain the data more easily; i.e., the user is able to easily operate the device while driving the car. The order of priority may be pronounced by voice.

0162The reference position KP may be fixed to the present position or to any predetermined objective place.

0163In this case, it may not be selected the reference position KP by the user. This makes it possible to decrease the amount of control processing and, hence, to provide a navigation device at a reduced price. The present invention can be applied to the navigation devices designed for use in vehicles other than automobiles, as well as in ships, aircraft, helicopters, and the like. The maps used for the navigation may be marine charts, submarine charts or the like charts other than road maps.