Touch panel device and display device using the same

Abstract

To provide a touch panel device capable of identifying a touch such as a long press.SOLUTION: A touch panel device 100 of the present invention includes a touch panel 110 and a controller 120 that scans the touch panel 110 and detects a touch based on sensing signals obtained by the scanning. The controller 120 calculates a change amount ▵T between the sensing signal of the previous frame and the sensing signal of the current frame, performs this calculation over a plurality of frame intervals, calculates an integrated value ▵c (▵c=▵T1+▵T2+▵T3, ..., ▵Tn-1) of the obtained plurality of change amounts (▵T1, ▵T2, ▵T3, ..., ▵Tn-1), and identifies the sensing signals as a long press touch when the integrated value ▵c is equal to or greater than a long press detection threshold Th_U.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a touch panel device that detects a touch operation, and more particularly to detection of a long press. [Background technology]

[0002] Touch panels are used as input interfaces that receive touch operations from users and are integrated into display units such as liquid crystal displays. Resistive and capacitive touch panels are widely used. Capacitive touch panels also come in surface capacitive and projected capacitive types.

[0003] Fig. 1 shows a schematic plan view of a projected capacitive touch panel (Patent Document 1). The touch panel 6 includes a touch sensor 11. The touch sensor 11 includes an X-side line sensor 12 aligned along the X direction and a Y-side line sensor 13 aligned along the Y direction. The X-side line sensor 12 has electrodes 14 aligned along the X direction arranged in parallel in the Y direction at intervals, and the Y-side line sensor 13 has electrodes 15 aligned along the Y direction arranged in parallel in the X direction at intervals. In the mutual capacitance method, for example, the X-side line sensors 12 are scanned sequentially, and the Y-side line sensor 13 senses the capacitance of the intersection between the electrodes 14 and 15.

[0004] In addition, the touch panel device of Patent Document 2 determines whether a contacting object is a foreign object based on a comparison between the actual measured value of the relative acceleration of the contacting object and the theoretical value of the relative acceleration of the foreign object, and the touch panel device of Patent Document 3, when it detects a change in capacitance but does not detect the proximity of an object using a proximity sensor, determines that the change in capacitance is due to a foreign object and not due to user operation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-77755 A [Patent Document 2] JP 2014-857717 A [Patent Document 3] JP 2012-138026 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a capacitive touch panel device, as shown in Fig. 2(A), a controller 20 scans / senses the touch panel 10 and detects an operation such as a touch at a position where a change in capacitance occurs, but this detection method has a problem in that it is difficult to distinguish whether the change in capacitance is caused by a long press by a person's finger U as in Fig. 2(A) or by the placement of an object 30 as in Fig. 2(B). The same problem exists with resistive film type touch panels.

[0007] 3, the conventional detection algorithm scans the touch panel 30, measures the sensing signal obtained by scanning (S100), and if the sensing signal is equal to or greater than the touch detection threshold Th (S110), then determines whether the sensing signal is a continuing signal (S120), and if the continuing signal is within a timeout period (S130), the sensing signal is deemed valid and the coordinates of the touch position detected by the sensing signal are notified to the user. On the other hand, if the continuing signal exceeds the timeout period, the sensing signal is deemed invalid, the data (sensing signal) is discarded, and the touch position is not notified to the user.

[0008] However, when such timeout processing is performed, for example, when a long press is performed for a long period of time to perform a fast-forward operation or a scroll operation, the touch operation is no longer detected due to the timeout processing in the middle of the operation, and as a result, the fast-forward or scroll movement stops and the user is required to perform the fast-forward or other operation again, reducing user convenience.

[0009] The present invention aims to solve the above-mentioned problems in the conventional art and to provide a touch panel device and a display device that can identify touches such as long presses. [Means for solving the problem]

[0010] The touch panel device of the present invention includes a touch panel and a control means for scanning the touch panel and detecting a touch based on a sensing signal obtained by scanning, wherein the control means calculates an amount of change between the sensing signal of a previous frame and the sensing signal of a current frame between multiple frames, calculates an integrated value of the multiple calculated amounts of change, and identifies whether or not a touch has occurred based on the calculated integrated value.

[0011] In one aspect, the control means calculates a plurality of integrated values ​​between a plurality of frames, and identifies whether or not there is a touch based on an average value of the plurality of integrated values. In one aspect, the control means further calculates a movement of a detection position based on the sensing signals of the plurality of frames, and identifies whether or not there is a touch based on the calculated movement of the detection position and the integrated value. In one aspect, the control means identifies whether or not there is a long press touch. In one aspect, the control means ends calculation of the integrated value when touch detection is released from the touch panel. In one aspect, the touch panel is a capacitive type or a resistive film type. Effect of the Invention

[0012] According to the present invention, since the touch is identified based on the integrated value of the change amount of the sensing signal between multiple frames, touch such as long press can be accurately detected without using the timeout process as in the conventional case. This enables the user to perform continuous operations (long press operation) such as fast forward and scroll movement, improving user convenience. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic plan view of a capacitive touch panel. [Diagram 2]1A and 1B are diagrams illustrating problems with a conventional touch panel device. [Diagram 3] FIG. 13 is a diagram showing an operation flow of a detection algorithm of a conventional touch panel device. [Figure 4] 1 is a diagram showing a configuration of a touch panel device according to an embodiment of the present invention; [Diagram 5] FIG. 5A shows an example of a waveform of a sensing signal when a long press is performed, and FIG. 5B shows an example of a waveform of a sensing signal when an object is placed on the touch panel. [Figure 6] FIG. 6(A) is a graph comparing the detection signal when there is a long press and the detection signal when an object is placed, and FIG. 6(B) is a graph comparing the integrated value when there is a long press and the integrated value when an object is placed. [Figure 7] FIG. 4 is a diagram showing an example of an operation flow of a detection algorithm of the touch panel device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, an embodiment of the present invention will be described. The touch panel device according to the present invention includes a touch panel and detects a touch of an operation target (for example, a user's finger). The touch includes contact with or proximity to the touch panel. The touch panel device according to the present invention may be either a capacitive touch panel or a resistive touch panel. The touch panel device according to the present invention provides a display device or a display unit mounted on a display such as a liquid crystal panel and equipped with a user interface function. Such a display device is used, for example, in an in-vehicle device, a multi-function mobile phone (smartphone), a portable information terminal (tablet computer, laptop computer, notebook computer), etc. EXAMPLES

[0015] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 5 is a block diagram showing the configuration of a touch panel device according to this embodiment. The touch panel device 100 includes, for example, a capacitive touch panel 110 and a controller 120 that performs touch detection on the touch panel 110.

[0016] 1, the touch panel 110 has a substrate such as glass or plastic on which transparent electrodes 14, 16 arranged in a matrix in the X and Y directions are disposed below an insulating film or the like. When a finger touches the touch panel 110, the electrostatic capacitance between the electrodes in the vicinity changes, and the touch position is detected by identifying this change in electrostatic capacitance as a row in the X direction and a row in the Y direction. The touch panel 110 is mounted, for example, on a liquid crystal panel (not shown), and provides a user input interface related to images displayed on the liquid crystal panel.

[0017] The controller 120 controls the overall operation of the touch panel 110. The controller 120 includes a drive circuit for sequentially scanning each electrode 14 of the X-side line sensor 12 shown in FIG. 1, and a sense circuit for sequentially sensing each electrode 15 of the Y-side line sensor 13, and the sense circuit measures a sense signal corresponding to the electrostatic capacitance generated at a position where the electrodes 14 and 15 intersect (hereinafter, a sensing area). The controller 120 or the sense circuit may include an amplifier circuit for amplifying an analog sense signal corresponding to the electrostatic capacitance of the sensing area, and an A / D converter for converting the amplified analog sense signal into a digital sense signal. The Y-side line sensor 13 may be the scan side, and the X-side line sensor 12 may be the sense side.

[0018] The controller 120 scans / senses the entire sensing area of ​​the touch panel 110 via the drive circuit / sense circuit, for example, every 2 to 3 milliseconds. Here, a group of sensing signals that are the measurement results of the entire sensing area of ​​the touch panel 110 is called a frame. Therefore, one frame is generated every 2 to 3 milliseconds. Usually, the time that a finger touches the touch panel 110 is at least several tens of milliseconds. If it takes 3 milliseconds to generate one frame and the finger touch time is 30 milliseconds, then 10 frames will be generated during the time that the finger touches. In addition, if the touch is long, the touch time may be several seconds to several tens of seconds.

[0019] The controller 120 detects a touch based on the sensed signal of each frame. In one embodiment, the controller 120 includes a microprocessor or microcontroller with a ROM / RAM or the like, and executes a program stored in the ROM / RAM to execute a touch detection algorithm.

[0020] Next, a method for identifying a long press in the touch panel device of this embodiment will be described. In a capacitive touch panel or a resistive touch panel, human operation (e.g., a finger) causes slight fluctuations in the capacitance or resistance value. In contrast, when an object is placed on the touch panel, the slight fluctuations in the capacitance or resistance value are very small. In this embodiment, it is possible to identify whether the operation is human (particularly a long press) or something else, based on the difference in behavior of the sensing signal when the operation is performed by a person and when an object is left standing.

[0021] 5(A) shows the waveform of a sensing signal when a capacitive touch panel 110 is touched by a human finger U, and FIG. 5(B) shows the waveform of a sensing signal when an object B is placed on the capacitive touch panel 110, the waveform lasting for about 10 seconds. When the finger U touches at time t1, the level of the sensing signal exceeds the touch detection threshold Th in response, and thereafter, the level of the sensing signal remains roughly constant but slight movement occurs. On the other hand, when the object B is touched at time t1, the level of the sensing signal exceeds the touch detection threshold Th in response, but there is almost no slight movement at this level. FIG. 6(A) is a graph that shows a schematic diagram of the actual waveform of a sensing signal when a finger is pressed and held (solid line) and an object is left (dashed line).

[0022] The controller 120 calculates the amount of change between the level of the sensing signal of the previous frame and the level of the sensing signal of the current frame for the sensing signal exceeding the touch detection threshold Th, calculates such amount of change between a plurality of frames, and integrates the amount of change. That is, when the levels of the sensing signals of the frames F1, F2, ..., Fn are T1, T2, ..., Tn, the controller 120 calculates T1-T2=ΔT1, T2-T3=ΔT2, T3-T4=ΔT3, ..., Tn-1-Tn=ΔTn-1. Then, it calculates an integrated value Δc=ΔT1+ΔT2+ΔT3, ...+ΔTn-1.

[0023] Fig. 6(B) is a graph showing a comparison between the integrated value Δc_U when a finger is pressed and held down and the integrated value Δc_B when an object is left standing. It can be seen that the integrated value Δc_U when a finger is pressed and held down becomes larger than the integrated value Δc_B when an object is left standing as time passes (i.e., the integrated number of changes between frames), and the difference between the two gradually increases.

[0024] Therefore, the controller 120 sets an appropriate long press detection threshold Th_U based on the relationship shown in FIG. 6B, and judges whether the integrated value Δc is equal to or greater than the long press detection threshold Th_U. If the integrated value Δc≧the long press detection threshold Th_U, the detection signal is identified as being caused by a long press by a finger, and if the integrated value Δc<the long press detection threshold Th_U, the detection signal is identified as being caused by something other than a long press by a finger (for example, an object being left behind). In one embodiment, the controller 120 may determine whether the integrated value Δc≧the long press detection threshold Th_U at a time corresponding to the time when the conventional detection algorithm times out (step 130 in FIG. 3). That is, the controller 120 calculates an integrated value Δc of the amount of change between frames for a plurality of frames buffered until the timeout occurs, and compares this integrated value Δc with the long press detection threshold Th_U. In one embodiment, the controller 120 may determine whether the integrated value Δc≧the long press detection threshold Th_U at a predetermined time or number of frames, regardless of the timeout time. In one embodiment, the determination of whether the integrated value Δc≧the long press detection threshold Th_U is performed continuously until the sensing signal becomes less than the touch detection threshold th, that is, until the touch is released. The integration of the change amount between frames may be terminated when the touch is released, or when a long press is identified by determining whether the integrated value Δc≧the long press detection threshold Th_U is satisfied.

[0025] Thus, according to this embodiment, it is possible to identify whether a long press has been performed by a human finger or an object has been placed on the touch panel without using a timeout process as in the past, which allows the user to perform continuous operations (long press operations) such as fast forwarding and scrolling, thereby improving user convenience. In addition, by accurately identifying a long press by a finger, it is possible to prevent malfunctions (unintended calibration operations, etc.).

[0026] Fig. 7 is a flow chart showing an example of the detection algorithm of this embodiment. The controller 120 scans the touch panel 30, measures a sensing signal obtained by scanning (S100), and judges whether the sensing signal is equal to or greater than the touch detection threshold Th (S110). For example, as shown in Fig. 5(A), when a finger U touches the touch panel 110, the capacitance of the touched sensing area changes, and a sensing signal exceeding the touch detection threshold Th is measured. The controller 120 identifies the touched sensing area from the columns in the X direction and the columns in the Y direction.

[0027] When the sensing signal is equal to or greater than the touch detection threshold Th, the controller 120 determines whether the sensing signal is a continuing signal (S120), and if it is a continuing signal, the controller 120 performs the above-described integration of the inter-frame change amount of the sensing signal for a plurality of frames and determines whether the integration value Δc≧the long press detection threshold Th_U (S200). In one aspect, when the controller 120 determines that the sensing signal is equal to or greater than the touch detection threshold th, it buffers the frame following the frame in a FIFO memory or the like, and determines whether the sensing signal is a continuing signal or not based on the buffered frame and calculates the integration value Δc.

[0028] The controller 120 calculates an integrated value Δc for a predetermined number of frames or a predetermined time period from touch detection, and if the calculated integrated value Δc is equal to or greater than the long press detection threshold Th_U (S200), the change in capacitance is identified as a long press by a finger (S210) and the coordinate position of the detected touch is notified to the user (e.g., a controller of a display device, etc.).On the other hand, if the calculated integrated value Δc is less than the long press detection threshold Th_U (S200), the change in capacitance is identified as an object being left behind, etc. (S220), the data (sensing signal) is discarded, and the coordinate position is not notified to the user.

[0029] Next, a modified example of this embodiment will be described. In the above embodiment, the integrated value Δc is compared with the long press detection threshold Th_U, but the controller 120 may calculate multiple integrated values ​​between multiple frames and compare the average value of the multiple integrated values ​​with the long press detection threshold Th_U. For example, the integrated value Δc_1 of each change amount from frame 1 to frame 3, the integrated value Δc_2 of each change amount from frame 4 to frame 6, and the integrated value Δc_3 of each change amount from frame 7 to frame 9 are calculated, and the average value Δc_AV=(Δc_1+Δc_2+Δc_3) / 3 is calculated, and it is determined whether Δc_AV is equal to or greater than the long press detection threshold Th_U. By such processing, it is sufficient for the buffer memory to store data for three frames, and the required memory capacity can be reduced.

[0030] As another modification, the controller 120 may use the movement of the detection position during the calculation of the integrated value. When an object is left on the touch panel, no change occurs in the detection position, but when a finger touches the touch panel, movement may occur in the detection position. If a swipe operation such as scrolling occurs, movement occurs in the detection position. Therefore, the controller 120 detects the touch position (the sensing area that generates a detection signal equal to or greater than the touch detection threshold Th) based on the detection signal of each frame, and calculates the movement or change amount ΔM of the detected touch position. The period (number of frames) for calculating the change amount of the touch position may be the same as the period (number of frames) for calculating the integrated value, or may be shorter than that.

[0031] The controller 120 makes it easy to identify a long press by weighting the accumulated value Δc by the movement ΔM, for example, such that (accumulated value Δc + movement ΔM) ≧ long press detection threshold Th_U, or (accumulated value Δc × movement ΔM) ≧ long press detection threshold Th_U.

[0032] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the gist of the invention described in the claims. [Explanation of symbols]

[0033] 12: X-side line sensor 13: Y-side line sensor 14, 15: Electrodes 100: Touch panel device 110: Touch panel 120: Controller U: Finger B: Object

Claims

1. A touch panel device including a touch panel and a control means for scanning the touch panel and detecting a touch based on a sensing signal obtained by scanning the touch panel, The control means calculates the amount of change between the level of the sensing signal in the previous frame and the level of the sensing signal in the current frame between multiple frames, calculates an integrated value of the amount of change in the multiple levels obtained by the calculation, and identifies whether or not there is a touch based on the calculated integrated value.

2. The touch panel device according to claim 1 , wherein the control means calculates a plurality of integrated values ​​over a plurality of frames and identifies whether or not there is a touch based on an average value of the plurality of integrated values.

3. 3. The touch panel device according to claim 1, wherein the control means further calculates a movement of the detection position based on the sensing signals of the plurality of frames, and identifies whether or not there is a touch based on the calculated movement of the detection position and the integrated value.

4. The touch panel device according to claim 1 , wherein the control means identifies whether or not the touch is a long press.

5. The touch panel device according to claim 1 , wherein the control means terminates the calculation of the integrated value when touch detection is released from the touch panel.

6. The touch panel device according to claim 1 , wherein the touch panel is a capacitive touch panel or a resistive touch panel.

7. A display device comprising the touch panel device according to claim 1 and a display.

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