Navigation apparatus and method for providing guidance to a vehicle user using a touch screen

0001The present invention relates to a navigation apparatus and method for providing guidance to a vehicle user using a touch screen.

0002The use of touch screens is widely known in display technology.

0003<patcit id="pcit0001" dnum="US6690387B2"><text>US 6,690,387 B2</text></patcit> discloses a touch screen control, wherein a scroll operation continues even after the finger has been taken off the screen and the scroll speed gradually decreases thereafter. A user can stop the scroll operation by touching the screen with the finger again.

0004<patcit id="pcit0002" dnum="JP5027744A"><text>JP 5-27744 A</text></patcit> discloses a touch screen control, wherein the sliding track of a finger is detected as a vector and used for controlling the scroll operation. The scroll operation stops when the finger is taken off the screen.

0005<patcit id="pcit0003" dnum="JP2006090962A"><text>JP 2006-90962 A</text></patcit> discloses a navigation system comprising a touch screen with a scroll operation control similar to the scroll control operation of <patcit id="pcit0004" dnum="US6690387B2"><text>US 6,690,387 B2</text></patcit> mentioned above.

0006<patcit id="pcit0005" dnum="JP2002213989A"><text>JP 2002-213989 A</text></patcit> discloses a navigation system comprising a touch screen with a scroll operation control, which uses a pressing force detection in that either the scroll operation is stopped, when no touching of the screen is detected anymore, or the scroll rate is reduced with increasing touch pressure.

0007In the application of touch screens in vehicle navigation systems, in particular with respect to scroll operations, it is an important aspect of the application that the user's attention is not distracted and the user is able to concentrate on the traffic. Therefore, the scroll operation should be as user-friendly as possible, in particular in terms of requiring the shortest possible attention to the touch screen when performing scroll operation.

0008It is an object of the present invention to provide an improved navigation apparatus and method for providing guidance to a vehicle user using a touch screen.

0009This object is achieved by an apparatus according to claim 1 or 2 or 6 or 13 and a method according to claim 11, respectively.

0010Further developments of the invention are given in the dependent claims.

0011The scroll operation control uses the measurement of the vector of a movement of a finger on a touch screen and the measurement of a pressing force of the finger on the touch screen.

0012If the movement speed exceeds a certain threshold i.e. if the absolute value of the vector exceeds a threshold value, it is assumed that the user wishes to change the scroll direction of the scroll operation.

0013If the pressing force does not exceed a force threshold, it is assumed that the user wishes to initiate a slight change of the scroll operation, which is accomplished by calculating a new combined control vector calculated from the measured movement vector and the previous control vector of scrolling.

0014If, on the other hand, the pressing force exceeds the force threshold, it is assumed that the user wishes to have a strong (abrupt) change of the scroll direction, such that the new control vector for the scroll operation is calculated based on the measured movement vector only without consideration of the previous control vector.

0015The consideration depending on exceeding or not exceeding the pressing force could also be made to the opposite, i.e. slight change with strong force and vice versa, but the above described dependency, i.e., combining the vectors when the pressing force does not exceed the force threshold, is preferred.

0016It is also possible to always use a combined control vector independent of the pressing force of the finger, but it is advantageous to make the above selection.

0017The use of the measured movement vector and of the measured pressing force is also advantageous in controlling the stopping of a scroll operation. If the absolute value of the movement vector is below a certain threshold, preferably if it equals zero, it can be assumed that the user wants to stop the scroll operation. Depending on the pressing force, the scroll operation can be stopped immediately, if the pressing force exceeds a force threshold indicating the user's wish to have a strong change of the scroll operation or the scroll speed can be gradually decreased, if the pressing force does not exceed the force threshold.

0018Again, the selection depending on the pressing force threshold can be opposite, but the above described manner is preferred.

0019Further features and advantages follow from the detailed description of embodiments referring to the figures. The figures show: <dl id="dl0001" compact="compact"><dt>Fig. 1</dt><dd>a navigation apparatus according to an embodiment of the present invention; and</dd><dt>Fig. 2</dt><dd>a flow chart of a method according to an embodiment of the present invention.</dd></dl>

0020A navigation apparatus for providing guidance to a vehicle user according to an embodiment of the present invention is shown in Fig. 1 and comprises a memory 10 for storing map/road data, a sensor unit 20 comprising a satellite positioning system (SPS) receiver 21 (such as a GPS receiver), a direction sensor 22, a magnetic sensor 23, a communication unit 24 such as a cellular telephone unit and other sensors, an input/output unit 30 comprising a speaker 31 and a touch screen display 32, and a control unit 40 connected to the memory 10, the sensor unit 20 and the input/output unit 30 and adapted to control the navigation apparatus and to generate information to be output to the user. The navigation apparatus may comprise other usual units/devices such as turn buttons, jog dials, microphone, keyboard, drives and so on. For the sake of brevity, such additional functional elements are not shown and discussed here, as the present invention relates to the operation of the touch screen in a navigation apparatus.

0021The control unit 40 is adapted to control the scroll operation of the touch screen 32 based on the measured vector of a movement of a finger on the touch screen. Additionally, a pressing force of the finger of the touch screen is measured i.e. the touch screen display 32 is adapted to measure such a pressing force.

0022The control unit 40 is adapted to control the scroll operation of the touch screen according to a process, an embodiment of which is shown in the flow chart of Fig. 2.

0023After start of the process, it is determined in step S 1 whether a touching of the screen was detected. If no touch was detected (N in step S1), a new control vector V₀ for the scroll operation is calculated in step S2 in that the previous control vector V₀ is multiplied with a value &lt;1, in the present example 0.8. It is obvious that, if the previous control vector V₀ = 0, the new control vector also equals 0.

0024After step S2, the process continues to step S2a, where it is determined whether the control vector V₀ exceeds a threshold G. The threshold G is set to a very low value such as 0.1mm/s. The threshold G serves to prevent an asymptotic calculation of the scroll vector V₀. If the scroll vector V₀ does not exceed the threshold G (N in step S2a), scroll vector V₀ is set to zero in step S2b to prevent such an asymptotic approach of the absolute value of V₀ to zero.

0025The process continues from steps S2a, S2b to step S3, where a scroll operation of the displayed map or of other display items such as street lists and so on is controlled using the new control vector V₀ calculated in steps S2, S11-S14, S16, S 17 and S2a, S2b.

0026If a touching of the touch screen was detected in step S1 (Y in step S1), a movement vector calculation for calculating a measured vector V₁ of a movement of a finger on the touch screen 32 is started in step S4. At first, in step S5, the X-Y coordinates of the touch position on the touch screen are stored (X1, Y1) in step S5. Then, after waiting a predetermined period of time ΔT (for example 100ms), the X-Y coordinates of the touch position on the touch screen are stored again (X2, Y2) in step S6.

0027It should be noted that the waiting time ΔT can be any reasonable value for measuring the movement of a finger on the touch screen, which also depends on the size of the touch screen. Accordingly, any value between 5ms and 1000ms could be set. Preferred values are in the range from 20ms to 300ms. For the sake of clarity, any intermediate value in the indicated range, i.e. 5ms, 6ms, 7ms, 8ms, ..., 33ms, 34, ms, 35ms, ..., 99ms, 100ms, 101ms, ..., 213ms, 214ms, ..., 998ms, 999ms, 1000ms can be selected for ΔT and also as an upper or lower range limit for ΔT values.

0028In step S7 a vector V₁ of the finger movement (=measured vector) is calculated according to the following formula <maths id="math0001" num="(1)."><math display="block"><msub><mi mathvariant="normal">V</mi><mn mathvariant="normal">1</mn></msub><mo mathvariant="normal">=</mo><mfenced separators=""><mi mathvariant="normal">X</mi><mo>⁢</mo><mn mathvariant="normal">2</mn><mo mathvariant="normal">-</mo><mi mathvariant="normal">X</mi><mo>⁢</mo><mn mathvariant="normal">1</mn><mo mathvariant="normal">,</mo><mi mathvariant="normal">Y</mi><mo>⁢</mo><mn mathvariant="normal">2</mn><mo mathvariant="normal">-</mo><mi mathvariant="normal">Y</mi><mo>⁢</mo><mn mathvariant="normal">1</mn></mfenced></math><img file="EP1882902A1_D0001.tif" /></maths>

0029In step S8, the pressing force F of the finger is stored. This pressing force F can be either the pressing force at position (X1, Y1) or at position (X2, Y2) or the average pressing force during the movement from position (X1, Y1) to position (X2, Y2) or another representative pressing force value. In the embodiment shown in Fig. 2, the average pressing force is stored.

0030After calculating the movement vector and storing the pressing force, it is determined in step S9, whether the absolute value of the movement vector V₁ exceeds a first threshold V_T. In the embodiment shown in Fig. 2, the first threshold V_T = 0. However, V_T could also be a low value such as 0.1 or 1 or 5mm/s or any intermediate value. The value of V_T=0 is preferred.

0031If the absolute value of the movement vector exceeds the first threshold V_T (Y in step S9), it is determined in step S10, whether the pressing force F of the finger exceeds a second threshold F_T.

0032If the pressing force of the finger exceeds the second threshold F_T (Y in step S10), it is assumed that the user wishes a strong change of the scroll operation and a new control vector V₀=V₁ is determined in step S11.

0033If, on the other hand, the pressing force does not exceed the second threshold F_T (N in step S10), a new scroll control vector V₀=V₀+V₁ is calculated in step S12 and determined to be the new scroll control vector V₀.

0034In step S13, it is determined whether the absolute value of the new scroll control vector determined in step S11 or S12 exceeds a maximum value V_max for the control vector. If not (N in step S13), the vector calculation is finished. Otherwise (Y in step S13) the absolute value of the new control vector V₀ is set to be the maximum value V_max in step S14 (with the same direction) and then the vector calculation is finished.

0035After the end of the vector calculation, the process proceeds to step S3 (via step S2a, S2b), where the scroll operation of the map or other display items is performed with the new control vector V₀.

0036If the movement vector V₁ does not exceed the first threshold V_T in step S9 (N in step S9), it is assumed that the user stopped his finger touching the touch screen, i.e. that the user wants to stop the scroll operation. In step S15, it is determined whether the pressing force exceeds a third threshold F_TS. If so (Y in step S15), the scroll operation is stopped immediately by setting the new control vector V₀ to zero in step S16.

0037Otherwise (N in step S15), the speed of the scroll operation is gradually decreased in step S17 (with preferably a stronger decrease rate than in step S2).

0038After step S16 or step S17, the process of calculating the control vector V₀ is finished and the process continues again to step S2a.

0039It is obvious to the skilled person, that the advantages of the calculation of a new combined control vector or of a new control vector without considering the previous control vector (steps S11, S12) are independent of the advantages of controlling the stop operation (steps S16, S17). Of course, both approaches use the measurement of the pressing force and of the movement vector, and, if combined, even enhance the effects.

0040It is also obvious, that the calculation of the new combined control vector from the measured movement vector and the previous control vector (step S12) can be used without the normal control vector calculation (step S11) and, consequently, without determining the pressure force. However, it is preferred to use the selection of the calculation methods in steps S11 and S12 based on the pressing force in step S10.

0041The teachings could also be applied to other touch screen display applications than navigations systems.

0042It is explicitly stated that all features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure as well as for the purpose of restricting the claimed invention independent of the composition of the features in the embodiments and/or the claims. It is explicitly stated that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure as well as for the purpose of restricting the claimed invention, in particular as limits of value ranges.