An electronic apparatus and a communication control method

Electronic equipment and communication control method

Cross-reference related applications The document of the present invention is based on the Japanese patent document JP 2003-298741 filed at the Japanese Patent Office on August 22, 2003, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic devices suitable for searching for connection target devices through wireless communication lines, providing wireless connections to the discovered devices to send and receive data, and communication in such electronic devices The control method is particularly suitable for electronic devices and communication control methods that use near-field wireless communication lines such as Bluetooth to communicate.

2. Description of related technologies Recently, Bluetooth has attracted attention as a near-field wireless data communication standard. In Bluetooth, Bluetooth-compatible wireless modules are already small in size, low in price, and low in power consumption, and can be easily embedded in portable devices such as digital still cameras and mobile phones. This makes it possible to simply wirelessly transmit and receive data such as images or voices between these devices or information devices such as PCs (Personal Computers). For example, there has been an idea that the image data captured by a digital still camera can be directly transmitted to a printer to print out the image without the intervention of a PC or recording medium.

If you use Bluetooth to perform file transfer or similar actions after connecting between a device and another device, the connection source device (master) must specify a target device (slave) to connect. In particular, the usual process is to search for surrounding Bluetooth devices on an initial connection, and select the target slave device for connection.

Because it is not always the first time to find the target slave device, according to this kind of search of the connected target device, in the traditional general method, the number of devices to be searched is approximately set to 5 to 10. However, if a large number of devices are discovered in such a situation, it is necessary to select a target slave device from them, for example, through user input. This may spoil the user experience.

On the other hand, a technique has been proposed in which the wireless power from the wireless module is reduced during the search to be lower than usual, making the searchable physical area narrower, causing the user to move the master device closer to the slave device to find The slave device. This technology increases the possibility of connecting to the target slave device at an early stage and provides users with an intuitive communication operation.

In addition, for example, if a large number of slave devices are found, there is a method to filter these devices based on whether a used application can be manipulated by slave devices, a type of slave device, or similar devices, and connect them automatically The slave devices that are considered to be available or only devices that are considered to be available are listed and displayed to the user to select one.

In addition, when the device address of the found slave device is registered and the device address is used to send to a connection operation, the operation load on the user and the cost of the device have generally been reduced. As such a wireless transmission device, there is a place where a registration switch is provided. In the wireless transmission device, when it is pressed, it starts the operation of finding the device on the slave side. If the device is found, the device address of the slave side is obtained, and then it is judged whether the registration switch is pressed. In the case of being pressed, it is determined that the registration is accepted, the device address obtained from the device on the slave side is stored in the memory, and the registration operation is terminated. (For example, refer to Patent Document 1) [Patent Document 1] Japanese Patent Application Publication No. 2003-037603 ([Figure

[0027] to

[0031], FIG. 2]) Here, in order to reliably connect to the target slave device within a short period of time, if there is no different Bluetooth device around the target slave device, the number of devices to be found is set to 1. However, in reality, there may be a large number of Bluetooth devices nearby. As a case, for example, there is a wireless communication mouse of a PC nearby a printer. As mentioned above, for this situation, it is feasible to make the wireless transmission power from this wireless lower than the wireless communication power from the wireless module during the search. Therefore, for example, there may be a situation where a different slave device that is found is connected, and despite further searching, the same slave device is found again. Therefore, it takes a long time to obtain the correct connection, which may make the user's operation feel worse.

In addition, when the number of devices searched is greater than 1, multiple slave devices are found, making it possible to mistakenly connect to a different slave device under the user's selection operation, or only slave devices other than the target device are found , Making the user try to choose one of them, and the result is a lot of time wasted.

In addition, if the found slave devices are filtered on the basis of the ability to execute the application program or the type of the device, it is possible that a large number of slave devices remain as selection targets after filtering. Therefore, letting users make choices is a difficult task. As mentioned above, it is not easy to improve the operating experience by providing a reliable connection to the target slave device as quickly as possible.

The present invention was developed in consideration of this problem, and an object of the present invention is to provide an electronic device that improves the operation experience of the slave device required by the user through wireless communication connection.

In addition, another object of the present invention is to provide a communication method that can improve the operating experience of a slave device required for a user's wireless communication connection.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, in an electronic device that searches for a connection target device through a wireless communication line and provides a wireless connection to the searched device to send and receive signals, an electronic device is provided, which features include: A wireless communication device for transmitting and receiving signals on a wireless communication line, a communication control device for controlling a communication program through the wireless communication device, and an attribute information storage device for storing in advance the attribute information of the connected target device. They are characterized by communication control The device determines the number of devices to be searched, and then sends an inquiry signal to obtain attribute information about the device that responds to the inquiry signal from the information received from the responding device, and compares it with the attribute information stored in the attribute information storage device, and in the case of consistency , The link to the responding device is established. In the case of inconsistency or no responding device, the number of search devices is increased to resend the interrogation signal.

Here, the wireless communication device transmits and receives signals through the wireless communication line, and the communication process is controlled by the communication control device. In addition, in the attribute information storage device, the attribute information of the connection target device is stored in advance before the establishment of the device connection. The communication control device determines the number of devices to be found, and operates the wireless communication device to send an interrogation signal indicating the determined number of devices to be found. In addition, the attribute information about the equipment in response to the inquiry signal is obtained from the reception information of the equipment responding to it, and compared with the attribute information stored in the attribute information device to determine whether the acquired attribute information is likely to come from the required equipment. high. When the compared information is consistent with each other, the wireless communication device is caused to establish and respond to the connection link of the device. In the case where the compared information is inconsistent with each other, or in the case where there is no device that responds to the interrogation signal, the number of devices to be searched increases to make the conditions for finding the required device better, and the interrogation signal is retransmitted.

In addition, in the above-mentioned electronic equipment, it is desirable to further provide a transmission power control device for reducing the transmission power during the first transmission of the interrogation signal to be lower than the power after the connection link is established.

In addition, in the above-mentioned equipment, it is desirable to further provide an identification information storage device for storing identification information indicating the equipment responding to the interrogation signal. The attribute information about the equipment responding to the first interrogation signal is stored in the attribute information storage device. When the attribute information of the device is inconsistent, the identification information of the device is stored in the identification information storage device to perform the retransmission of the query signal, so that only the identification information about the device that responds after the retransmission is stored in the identification information storage device When the information stored in the identification information of the device is inconsistent, the attribute information about this device is compared with the information stored in the attribute information storage device. If the former information is consistent with the latter in the attribute information storage device, the communication The control device establishes a connection link to the device.

In addition, in a communication control method suitable for searching for a connection target device through a wireless communication line to perform transmission and reception of signals by a wireless connection to the searched device, the present invention provides a method having the following characteristics, wherein The attribute information is stored in advance, and the number of devices to be searched is determined, the query signal is sent on the wireless communication line, the attribute information of the device responding to the query signal is obtained from the receiving information of the responding device, the attribute information and the pre-stored attributes The information is compared, in the case of agreement, a connection with the responding device is established, in the case of inconsistency, or in the case of no responding device, the number of searched devices is increased, and then the interrogation signal is retransmitted.

In this communication control method, the number of devices to be searched is determined, and then an inquiry signal is sent on the wireless communication line. The attribute information of the device responding to the inquiry is obtained from the information received by the responding device, and compared with the pre-stored attribute information to determine whether the possibility of the device being the required device is high. If the compared information is consistent with each other, a connection link with the responding device is established. If the compared information is inconsistent with each other, or there is no device that responds to the interrogation signal, increase the number of devices to be searched, and re-send the interrogation signal to provide conditions that can more easily find the desired device.

In addition, it is desirable that the transmission power at the first transmission of the interrogation signal is reduced lower than the power after the connection is established.

In addition, it is expected that if the attribute information about the device responding to the first interrogation signal is inconsistent with the pre-stored attribute information, the identification information of the device is stored in the memory, and the interrogation signal is retransmitted. Only when the identification information about the device after the response is retransmitted is inconsistent with the identification information stored in the memory, the identification information about the responding device is compared with the pre-stored identification information. The former information is compared with the pre-stored latter information. If they are consistent, a connection to the responding device is established.

BRIEF DESCRIPTION OF THE DRAWINGS With the accompanying drawings, the above and other objectives, features and advantages of the present invention will become more apparent through the detailed description of the presently best exemplary embodiments of the present invention given below. Among them: FIG. 1 is a diagram illustrating an example of the system structure of a wireless communication system according to an embodiment of the present invention; FIG. 2 is a block diagram illustrating an example of the internal structure of a DSC; FIG. 3 is a diagram illustrating an example of the internal structure of a Bluetooth module Figure 4 is a block diagram illustrating an example of the internal structure of the printer; Figure 5 is a flowchart describing the first control example during a wireless connection; Figure 6 is a flowchart describing the second control example during a wireless connection; 7 is a flowchart describing the third control example during wireless connection.

Detailed description of preferred embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating an example of the system structure of a wireless communication system according to an embodiment of the present invention.

The present invention is applicable to devices that perform wireless communication in a relatively short distance. This embodiment assumes a wireless communication system that uses Bluetooth as a wireless communication standard for communication. The wireless communication system includes, as shown in FIG. 1, a digital still camera (hereinafter referred to as a DSC) 1 and a printer 2. The DSC1 records the captured still image on the recording medium as digital system image data, and wirelessly transmits the recorded image data in accordance with the Bluetooth method. The printer 2 prints on a sheet of preset paper based on the image data received wirelessly.

In addition, the embodiment of the present invention assumes that the image data captured and recorded on the recording medium in the DSC1 is sent to the printer 2. However, it is assumed that in the current wireless communication system, there may be other devices that can communicate wirelessly according to the Bluetooth method around these devices, which are not shown here. In this embodiment, such a device as a wireless communication mouse, PC, mobile phone, PDA (Personal Digital Assistant) or the like is given. In the present invention, under such conditions, if the wireless connection from the DSC1 operating as the master device to the printer 2 as the slave device is used to perform communication, erroneous connections with different devices are prevented, so for the user DSC1 The operating ability can be improved.

FIG. 2 is a block diagram illustrating an example of the internal structure of the DSC1.

As shown in Figure 2, the DSC1 includes a camera module 11 with image capture function connected via a bus, a signal processing LSI for analog-to-digital conversion, data format conversion processing or similar processing for captured image signals, including temporary storage A VRAM (Video Random Access Memory) or a memory-like memory 13 of image data or similar data, read/write (R/W) for writing to or reading from a memory card 14a as a detachable semiconductor memory 14. A monitor 15 for displaying images, an input part for inputting user operations, and a control microcomputer 17 for controlling the entire device. In addition, a Bluetooth module 18 that wirelessly communicates with an external device is connected to the control microcomputer 17.

The camera module 11 includes an optical system including a lens, an aperture, a shutter, and an imaging element or the like to convert incident light from an object, such as a CCD (Charge Coupled Device).

The signal processing LSI12 realizes the conversion process from the output signal of the imaging element to the digital signal, the noise removal process, the image quality correction process, the conversion process into the luminance signal and the color difference signal, and the standard such as JPEG (Joint Photographic Experts Group) or similar The encoding process of the preset data format. In addition, it performs a decoding process, data formatting and result conversion process or the like on the image data read from the memory card 14a.

The memory 13 stores various application programs suitable for capturing images, image recording and playback operations, and wireless communication and necessary data, and temporarily storing data such as images during the execution of these processes.

R/W 14 writes image data converted into a preset data format in the signal processing LSI 12 on the memory card 14a, and reads the image data stored in the memory card 14a to send it to the control microcomputer 17 or signal processing LSI12.

The monitor 15 includes, for example, an LCD (Liquid Crystal Display) or the like, capable of displaying an image captured by the camera module 11, a so-called image through the camera, and further displaying an image read from the memory card 14a.

The input section 16 includes, for example, a shutter release button that operates the shutter of the camera module 11, a selection switch that selects an operation mode, or the like to provide an instruction input signal corresponding to the control microcomputer 17 operated by the user.

The control microcomputer 17 is adapted to control each circuit module of the DSC1, and when it is necessary to control each circuit module based on an instruction input signal from the input section 16, it executes the control processing section of the application program stored in the memory 13.

The Bluetooth module 18 includes, for example, an antenna and a transceiver suitable for signal transmission and reception of RF (Radio Frequency) according to the frequency hopping type of the frequency extension method, a processor or similar processor for implementing baseband processing, and a control micro The processor 17 has a processing interface to perform wireless communication with an external device such as the printer 2 in accordance with a communication process controlled by the control microcomputer 17.

In such a DSC 1, the signal processing LSI 12 displays the image signal captured by the camera module 11 on the monitor 15 under the control of the control microcomputer 17. In addition, when the shutter of the camera module 11 is ejected in response to an instruction input signal input from the input section 16, in the signal processing LSI 12, the captured image signal is converted into digital data in a preset data format and sent to the R/W14 And record it on the storage card 14a. In addition, the image data recorded on the memory card 14a is read out and decoded by the signal processing LSI 12, and the reproduced image can be displayed on the monitor 15. In addition, the read-out image data can be wirelessly transmitted to an external device including the printer 2 through the Bluetooth module 18.

Here, FIG. 3 is a diagram illustrating an example of the internal structure of the Bluetooth module 18.

As shown in FIG. 3, the Bluetooth module 18 includes a baseband circuit 181, an RF transmitting and receiving circuit, a control part 183, and an RF oscillator 184.

The baseband circuit 181 includes, for example, a memory suitable for temporarily storing data received from the control microcomputer 17 and the RF transmission and reception circuit 182, and a signal processing circuit suitable for physical (RF) layer control or the like, so as to provide data from the control microcomputer. The data of the computer 17 provides a communication link, and performs a data packet retransmission process, an error check process and similar processes.

The RF transmission and reception circuit 182 includes a transmission circuit and a reception circuit suitable for wireless communication. More specifically, for example, a digital-to-analog converter (DAC) 182a, a low-pass filter 182b, an IQ modulator 182c, a transmitting amplifier 182d, a radio frequency switch circuit 182e, a receiving amplifier 182f, an IQ demodulator 182g, a band-pass filter 182h, The frequency discriminator 182i, the FM demodulator 182j, the analog-to-digital converter (ADC) 182k and the antenna 1821.

The signal provided from the baseband circuit 181 is converted into an analog signal by the DAC 182a, and its high-frequency component is removed by the low-pass filter 182b, and then modulated by the IQ modulator 182c. The IQ modulator 182c performs spectrum expansion of the frequency hopping method on the basis of the reference waveform from the RF oscillator 814. The modulated signal is amplified by the transmission amplifier 182d, and is supplied to the antenna 1821 through the RF switch circuit 182e for wireless transmission. In addition, the gain of the transmission amplifier 182d is controlled by a control signal from the control section 183.

On the other hand, the signal received by the antenna 1821 is supplied to the receiving amplifier 182f through the RF switch circuit 182e, amplified there, and then demodulated by the IQ demodulator 182g based on the reference waveform from the RF oscillator 814. In addition, its bandwidth is limited by the band-pass filter 182h, and then the signal is down-converted to an intermediate frequency by the frequency discriminator 182i by the FM demodulator 182h or ADC 182k, and then provided to the baseband circuit 181.

The control section 183 controls the corresponding modules in the Bluetooth module 18 based on the information input from the control microcomputer 17 through the baseband circuit 181. Here, during the transmission of the interrogation signal to the slave device responding to the control signal from the control microcomputer 17, the control section 183 can reduce the transmission power by reducing the gain of the transmission amplifier 182d, which is lower than the transmission power after the communication connection is established. In addition, it is also possible to gradually control the transmission power.

The RF oscillator 184 includes an oscillator and a PLL (Phase Locked Loop) or the like to provide a reference waveform for frequency hopping to the IQ modulator 182c and the IQ demodulator 182g.

Next, FIG. 4 is a block diagram illustrating an example of the external structure of the printer 2.

As shown in FIG. 4, the printer 2 includes a Bluetooth module 21 having the same functions as the Bluetooth module 18 included in the DSC1, which are all connected via a bus, a control microcomputer 22 for controlling the entire device, and a memory 23 for temporarily storing data. , A signal processing LSI 24 for performing a demodulation process or the like of received image data, a printing module 25 for printing an image on a page of printing paper, a display portion 26 for displaying the operating status or the like, and a The input part 27 manually operated by the user.

The Bluetooth module 21 performs wireless communication between external devices including the DSC1 under the control microcomputer 22. The control microcomputer 22 is a control processing part that controls each circuit unit of the printer 2, and based on the instruction input signal from the input part 16 or the data received through the Bluetooth module 21, controls the receiving circuit unit, and at the same time executes the The application program of the memory 23.

The memory 23 includes ROM, RAM, or the like for storing application programs or data used for printing operations and wireless communication or the like. In addition, it temporarily saves the data during the receiving and printing operations of image data. The signal processing LSI 24 performs a decoding program and a result conversion process on the image data or the like.

The printing module 25 includes a paper insertion part, a paper supply device, a printing device or the like, and prints an image on a set of paper based on the input image data. The display section 26 includes, for example, LEDs (Light Emitting Diodes) or the like to display the operation status of the printer 2 including the printing operation and the data receiving operation, and the operation mode and the like. The input section 27 includes button switches operated by the user to perform paper supply, operation mode setting, and the like.

In such a printer 2, through the Bluetooth module 21 under the control of the control microcomputer 22, wireless communication with an external device such as the DSC1 is performed to receive image data. The received image data is subject to the decoding process or the like in the signal processing LSI 24, and then sent to the printing module 25 that performs the printing operation.

Here, in Bluetooth, in order for the master device to obtain a connection to the target slave device, it is necessary for the master device to broadcast an inquiry message on the wireless communication line and find the responding device. However, if there are a large number of Bluetooth devices around the main device, the main device receives responses from these devices, so it is necessary to select the target device.

Here, the signal transmission area of the Bluetooth signal is about 10 meters. Reducing the power during the sending of the inquiry message narrows the area that the message can reach, so only the slave devices adjacent to the master device respond. This makes it easy to find the target device. For example, if the master device or the slave device as the connection target is of a portable type, then on connection, this portable device can be exposed to the partner device after approaching the partner device. As a result, the user is provided with a similar connection operation, and the connection to the target device is provided more reliably.

However, with the increase in the number of Bluetooth devices, although the response message is sent with a lower transmission power, the target slave device does not always exist in the area where the signal can be reached, so even with the above-mentioned method, it is possible to receive To the response from a large number of slave devices.

On the other hand, set the number of devices searched by the master device as small as possible to limit the devices that respond. However, if there are a large number of slave devices in the signal reachable area, it is possible that the responding device does not include the target device in the early stage. This cannot prevent incorrect connections.

Therefore, it is necessary to perform filtering based on the information of the responding device, and automatically determine whether the responding device is the target device or which device is the target device out of multiple responding devices. The use of such filtering reduces the possibility that the user must select an operation from the response device.

In the case of Bluetooth, in the above-mentioned interrogation procedure, the interrogation frequency hopping system is defined as two separate carriers, where each carrier is interrogated at least 256 times in a period of 10 milliseconds. Therefore, the inquiry status of each carrier lasts for 2.56 seconds, so it takes 10 seconds or more to establish the connection link. Therefore, the judgment made about whether the connection is wrong through filtering after the connection link is established may greatly destroy the user's operating experience.

On the other hand, in response to the inquiry message, the master device is notified about the device address of the slave device. At this point, the master device requests the responding slave device to obtain information on the service type (service level), device type (device level), and device name (device name) corresponding to the slave device. Therefore, in the present invention, the execution of filtering based on the information obtained before the establishment of the connection link, without the user's selection operation, can provide the connection in a short time interval, and reduce the possibility of erroneous connection, fully Increase the user's operational capabilities during the connection.

Next, in connection with the assumption that the image data recorded on the memory card 14a of the DSC1 is wirelessly transferred to the printer 2, three control examples regarding the communication program on the wireless connection of the control microcomputer 17 of the DSC1 are given.

The first control instance is described as the first control instance when the number of devices to be found in the initial condition is set to 1. In this control example, a device found for the first time is filtered. If it is an available device, the process proceeds to the connection operation. If the device is not available, increase the number of devices to be searched, and perform the search again. In addition, in addition to the devices that respond to this re-search, the devices that respond to the first search are excluded, and the remaining devices are filtered, which reduces the possibility of incorrect connections.

Fig. 5 is a flowchart illustrating a first example of control during a wireless connection.

In step S501, in response to the user's operation, the image transfer application is activated. During this period, the application information to be used is determined as the initial setting. Here, it is assumed that filtering is performed on the basis of the service level of the device that responds to the inquiry, and therefore all service levels that can transfer images are set to the memory 13. In addition, the number of discovered devices is set to 1.

In step S502, a control command to reduce the transmission power is issued, so that the gain of the amplifier 182d in the Bluetooth module 18 is lower than the gain in the usual case. Then, make the Bluetooth module send an inquiry message to perform device search.

In step S503, a response message in response to the inquiry is obtained from the Bluetooth module 18. In the case where the number of responding devices is 1, the process proceeds to step S504, and in the case where there is no responding device, the process proceeds to step S507.

In step S504, the information of the application program operable by the responding device is obtained and compared with the information of the used application program determined in step S501. More specifically, the service levels are compared.

In step S505, as a result of the comparison, if the responding device is capable of operating the target application (here, the device has a service level capable of transferring images), the process proceeds to step S512. If not, the process proceeds to step S506.

In step S506, the identification information about the responding device is temporarily stored in the memory 13. Here, for example, the device address obtained during the response is stored.

In step S507, the gain of the transmit amplifier 182d of the Bluetooth module 18 is increased to increase the transmit power higher than the power found in the first search. In addition, the number of devices being searched is set to 2, and the inquiry message is sent to continue the search.

In step S508, if the number of responding devices is 1 or more, the process proceeds to step S509. If there is no responding device, the process proceeds to step S513. In step S509, other than the responding device, devices having the same device addresses as those stored in step S506 are excluded. Here, the use of the device address inherent in the Bluetooth module of the device as a comparison target is definitely excluded from the first query response and is judged to be an unusable device, thereby avoiding the connection to these excluded devices.

In step S510, the device information (here, the service level) retained as the comparison result of step S509 is compared with the information of the application program used in advance.

In step S511, if one or more devices can transfer images, the process proceeds to step S512. If not, the process proceeds to step S513.

In step S512, it is determined that a device capable of transferring images is discovered. Here, if it is determined in step S505 that it is an available device (that is, a device that can operate an application program and transfer images), and if there is only one available device, for example, the device name of this device is displayed on the monitor 15. When the user performs an input operation after confirming that it is the target device, a connection link to the device is established. In addition, the connection link can be automatically established without user's operation. The establishment of the connection link realizes the image transfer. On the other hand, if there are 2 available devices in step S511, for example, the device names of these devices or the like are displayed on the monitor 15, and then a connection link to the device selected by the user's operation is established.

In step S513, it is determined that no usable device is found, for example, the user is notified about this through the identification on the monitor 15.

In addition, in the inquiry scan state, the slave device side (for example, printer 2) waits for an inquiry message from another Bluetooth device. When a message is received, the slave device sends a response message to the master device, and then changes to the slave response state. The slave response state allows to respond to the request from the master device and send the master device including device address, service level, device level, device name, or similar information. When the synchronization confirmation packet is sent from the master device, the state changes to the connected state. If this data packet cannot be received within the preset time interval, the state returns to the inquiry scan state.

In the above process of the flowchart, when the response from the slave device (here, the printer 2) that can operate and use the application program is received through the first search in step S502, the connection link can be established within a short period of time. .

In addition, in the case of a slave device that is not the target device (such as a wireless communication mouse), in the case of responding to the first search, it is filtered by comparison in the used application to avoid wrong connection. Therefore, the second time in step S507 The search, for example, is performed automatically again. Here, if only the same device is found in the second search, it is judged that the available device is not found, so that the wrong connection can be avoided. This also prevents the user from being asked to disconnect the wrong connection.

In addition, in the second search, expand the search area to increase the number of search target devices to increase the possibility of discovering target slave devices. This can lead to the possibility of two devices responding. However, in the process of step S509, devices that overlap with the device searched for the first time are found and excluded, so that other devices are filtered. Then, if the filtered one is judged to be an available device, the user is notified about this. In other words, when two devices respond, the user is only notified that one device has a high probability of becoming a target device, so that the user can continue the connection operation without interference.

In addition, if the device cannot be found in the first search, and two are found in the second search, the comparison in the application in use can select the device with a high probability of being the target device. In addition, in the second search, set the number of search devices to 2, to avoid many devices being discovered and users hesitating in selection.

As mentioned above, although the number of devices to be searched is set to 1 in the first search, at the end of the above process, the possibility of discovering the target device increases, so that the establishment of the connection link can be provided in a short time interval. In addition, if the target device is not found, before the connection link is established, the user is notified about this, so that the user can perform, for example, as the location of the master device or the slave device changes, quickly re-search operations, where the pressure in the operation Is reduced.

The second control example will next describe the case where the number of devices found in the original condition is set to 2. The second control paradigm makes use of the fact that if there is only one responding device despite the number of devices being found is set to 2, then this device is highly likely to be the target device. In other words, if there is only one response search, there is no need to doubt that the responding device is a usable device. If there are 2 responding devices, the available devices are judged after filtering.

Fig. 6 is a flowchart describing a second example of controlling wireless communication.

In step S601, the application program of the image transfer is activated to determine the information of using the application program (here, the service level), and the number of searched devices is also set to 2.

In step S602, the transmission power is reduced, and then the Bluetooth module 18 is caused to send an inquiry message to find the device.

In step S603, if a device responds to the inquiry, the process proceeds to step S612. If two devices respond, the process proceeds to step S604. In addition, if there is no response from the device, the step proceeds to step S607.

In step S604, the information of the application that can be operated by the responding device (here, the service level) is obtained and compared with the predetermined information of the used application.

In step S605, if the comparison result indicates that the responding device can process the target application, the process proceeds to step S612. If there is no available device (ie, a device capable of operating the application program), the process proceeds to step S606.

In step S606, information (device addresses) about all responding devices is temporarily stored in the memory 13.

In step S607, the transmission power from the first search is increased, the number of searched devices is set to 3, and then an inquiry message is sent to perform the search.

In step S608, during the search, the device address of the responding device is compared with the device address stored in step S606 to perform device overlap.

In step S609, if a response device reservation is overlapped by the excluded device, the process proceeds to step S612. If 2 devices are reserved, the process proceeds to step S610. In addition, if there is no reserved device, the process proceeds to step S613.

In step S610, the information about the reserved 2 devices is compared with the information of the preset used application program.

In step S611, if one or more devices capable of transferring images exist, the process proceeds to step S612. If no device exists, the process proceeds to step S613.

In step S612, it is determined that a device capable of transferring an image is found. Here, if it is determined in steps S603 and S609 that the device is an available device, and there is an available device in step S611, for example, notify the user about the device name of the device, and respond to the user's input operation, or automatically establish a connection link. In addition, if there are 2 available devices in step S611, for example, the device names of these devices or the like are displayed on the monitor 15, and then a connection link to the device selected by the user's operation is established.

In step 6513, it is determined that no corresponding available device is found, and then, for example, the identifier is used on the monitor 15 to notify the user about this message.

In the above process, if only one slave device responds in the first search, this device is judged to be an available device. If the number of devices being searched is plural, and only one device responds, the device has a high probability of being the target device, so it can provide a connection to the target device in a short time interval. In the second search, after performing device overlap, the number of devices is also plural, and the number of devices searched is also 2. Therefore, if the number of reserved devices is 1, it is determined that the available device has a high probability of being the target device.

In addition, in the case of multiple devices responding, filtering based on service level increases the possibility of discovering the target device. Here, in the above process, a large number of devices with matching service levels may be found and users are notified about this. In addition, it may also be found that there is no target device with the same service level. However, when the searchable area is limited in the first search, the number of devices to be searched is as small as possible (ie, 2), and the number of devices is not too large in the second search, which can be avoided Such a possibility. Therefore, the possibility of requiring the user to select an operation or establish a connection to a non-target device becomes very low, so the user's operating pressure can be reduced.

Third Control Example FIG. 7 is a flowchart illustrating a third control example during a wireless connection.

In the flowchart of FIG. 7, what is different from FIG. 6 is that in FIG. 7, if one or more responses are received in the judgment of step S703, the comparison based on the application program used in step S704 is always performed, Then determine the available equipment. In addition, also in the second search, when one or more responses are received in step S708, a comparison based on the used application is always performed to reserve the device after the device overlap is performed in step S709. In other words, in the third control paradigm, performing filtering on all responding devices increases the likelihood of discovering the target device. In addition, the second example of similar control restricts the number of searched devices to prevent interference with the user's choice of connection target due to a large number of device responses.

In addition, in the above example, the service level is used to filter response devices. However, in addition, for example, equipment class or equipment name can be used for filtering. In addition, the mixed use of these pieces of information can increase the possibility of discovering the target slave device.

Furthermore, in the case of the present invention, the above-mentioned embodiment is applied to the DSC to wirelessly communicate with the printer device. However, the present invention can also be applied to other devices. For example, the present invention is applied to another device such as a digital video camera, a portable telephone device, a PDA, a remote control device, a still video replay device and a video recording and replay device, a PC, a printer device, and the like. Here, it is desirable that at least the master device or the slave device that becomes the connection target to which the present invention is applied is a small-sized portable device. This reduces the transmission power on the inquiry transmission sent by the master device, which causes one device to approach another device to provide wireless communication. This provides the user with a natural operating feeling.

For example, the present invention can be applied to a case where an imaging device as a master device is wirelessly connected to a portable telephone device used as an access point to a wide network such as the Internet, and data transmission and reception from the imaging system are performed to the wide area network .

The present invention is also applied to a portable telephone device or a special remote control device as a master device, which is wirelessly connected to a device such as a video device or an imaging device to remotely control a slave device. The present invention is further applied to provide a wireless connection by bringing them close to the PC as the host device, which is recognized as a wireless communication mouse, portable external storage device, or the like, so that input operations to the PC are performed through the mouse or between the PC and the external Exchange stored data between storage devices.

In the electronic device according to the present invention, when the required device is found in the first inquiry, the judgment on whether to establish a connection by comparing the attribute information increases the possibility of correctly connecting the required device in a short period of time. In addition, if a non-target device is found during the first query, and if there is no responding device, a re-search is performed again. By increasing the number of devices to be searched, the conditions for searching for the selected device become better, eliminating the need for users Continue to search for the required equipment. Therefore, in a short period of time, it is possible to more reliably provide the connection to the desired device with an improved user's operating feeling.

In addition, in the first transmission of the inquiry signal, a transmission power control device suitable for reducing the transmission power lower than the transmission power after the connection link is established is provided, so that, for example, the transmission of the first inquiry can increase the need for discovery. Possibility of equipment.

In addition, for example, there is provided an identification information storage device for storing identification information that identifies a device responding to an interrogation signal. In the case where the attribute information about the device responding to the first inquiry signal is inconsistent with the attribute information stored in the attribute information storage device, the identification information is stored in the identification information storage device, and then the retransmission of the inquiry signal is performed. Only when the identification information about the responding device is inconsistent with the information stored in the identification information storage device after the retransmission, the attribute information about the responding device is compared with the information stored in the attribute information storage device, if the former information is compared with the latter Are consistent with each other, the communication control device is set to establish a connection link to the target device, so that the non-target device can be found through the second query. Therefore, the user is not forced to select an invalid operation from the found device, so the operation feeling is further improved.

In addition, in the communication control method according to the present invention, if the required device is found through the first inquiry, it is judged whether to establish a connection by comparing the attribute information. This increases the possibility of correctly connecting the required equipment in a short period of time. In addition, in the first query, when a non-target device or a non-responsive device is found, the number of devices to be searched is increased to improve the conditions for finding the required device, and to perform the query again, so that no user's request is required. The operation continues to find the required equipment. Therefore, the connection to the desired device with an improved user's operating feeling is more surely provided in a short period of time.

In addition, for example, in the transmission of the first interrogation signal, the transmission power is reduced to be lower than the power provided after the establishment of the connection link, so the possibility of finding the required equipment can be increased compared to the first interrogation. The possibility is great.

In addition, for example, in a case where the attribute information about the device that responded to the first interrogation signal is inconsistent with the attribute information pre-stored in the attribute information storage device, the identification information about the responding device is stored in the memory, and the interrogation signal is executed. Retransmission. Only when the identification information about the responding device after retransmission is inconsistent with the identification information stored in the memory, the attribute information about the responding device is compared with the pre-stored attribute information. If the former's information is consistent with the latter's pre-stored information, a connection to the target device is established. Thus, the user is not forced to select an operation invalidly from the searched device, so the operation feeling is further improved.