Display device with touch panel and control method thereof

Abstract

Provided are a display device with a touch panel and a control method for a display device with a touch panel, which can detect touches by fingers or pens, etc., even when controlled by a variable frame rate. The display device (100) comprises: a touch panel (1), a panel control unit (2), and a storage unit (52) for storing video signals. The panel control unit (2) causes touch detection processing and writing processing to be performed alternately during video input, and causes touch detection processing to be performed at equal time intervals during a pause period. Furthermore, the panel control unit (2) causes writing processing to be performed after the touch detection processing being performed or the touch detection processing to be performed next is completed at the beginning of the video input period.

Description

Technical Field

[0001] The present disclosure relates to a display device with a touch panel and a control method of the display device with a touch panel. Background Art

[0002] Conventionally, there are known display devices with touch panels having video display functions and touch detection functions, and methods for controlling such display devices with touch panels. Such display devices with touch panels and methods for controlling such display devices with touch panels are disclosed in Patent Document 1, for example.

[0003] In the display device with a touch panel of the above-mentioned Patent Document 1, the display operation of updating the display content for one frame of image information and the touch detection operation of detecting the touch of a finger on the touch panel are performed in time division. In addition, in the display device, the detection surface touch detection period until the detection of one detection surface as a whole is completed is set to be longer than the frame display period for performing the display operation.

[0004] Furthermore, conventionally, there is known a display device that performs control by a variable frame rate in which the length of a period per one frame is changed.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2017-130040 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] Here, it is also desirable for the display device that performs control by a variable frame rate to have a function of detecting a touch by a finger, a pen, or the like.

[0010] Therefore, the present disclosure is completed to solve the above-mentioned problems, and its purpose is to provide a display device with a touch panel and a control method for the display device with a touch panel, which can detect touch by a finger or a pen even when controlled by a variable frame rate.

[0011] Solutions for solving problems

[0012] In order to solve the above-mentioned problems, a display device with a touch panel according to the first aspect of the present disclosure is a display device with a touch panel that operates at a variable frame rate. The variable frame rate is achieved by changing the length of the pause period between a video input period and a pause period that constitute one frame. During the video input period, a video signal is supplied to the display device with a touch panel, and during the pause period, a video signal is not supplied to the display device with a touch panel. The display device with a touch panel comprises: a touch panel including pixel electrodes; a control unit that controls display and touch detection performed by the touch panel; and a storage unit that stores the video signal. The control unit comprises: a touch detection control unit that During the video input period and the pause period, touch detection processing is performed by the touch panel; a display control unit performs a write process during the video input period, the write process outputs the video signal stored in the storage unit to the touch panel, and writes a data signal based on the video signal to the pixel electrode; and a timing control unit alternately performs the touch detection process and the write process during the video input period, and performs the touch detection process at least at equal time intervals during the pause period, and the timing control unit performs the write process at the beginning of the video input period after the touch detection process being executed or the touch detection process to be executed next is completed.

[0013] The control method of a display device with a touch panel according to the second aspect is a control method of a display device with a touch panel that operates at a variable frame rate, the touch panel includes pixel electrodes, the variable frame rate is achieved by changing the length of the pause period between a video input period and a pause period that constitute one frame, a video signal is supplied to the display device with the touch panel during the video input period, and a video signal is not supplied to the display device with the touch panel during the pause period, and the control method of the display device with the touch panel comprises the following steps: storing the video signal in a storage unit; during the video input period, alternately executing touch detection processing and writing processing, the touch detection processing being performed by the touch panel, the writing processing outputting the video signal stored in the storage unit to the touch panel, and writing a data signal based on the video signal to the pixel electrode; during the pause period, executing the touch detection processing at least at equal time intervals; and executing the writing processing after the touch detection processing being executed or the touch detection processing to be executed next is completed at the beginning of the video input period.

[0014] Effects of the Invention

[0015] In the display device with a touch panel and the control method of the display device with a touch panel constructed as described above, since the write processing is performed after the touch detection processing in progress or the touch detection processing to be performed next is completed at the beginning of the video input period, the touch of a finger, a pen, etc. can be detected even when controlled by a variable frame rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a block diagram showing the configuration of a display device according to one embodiment.

[0017] Figure 2 It is a schematic plan view for explaining the arrangement of touch detection electrodes in a touch panel.

[0018] Figure 3 This is a circuit diagram for explaining the connection relationship between thin film transistors in a touch panel.

[0019] Figure 4 This is a timing chart for explaining the touch detection process and the writing process in the normal driving state.

[0020] Figure 5 A diagram for explaining a finger touch mode and a pen touch mode.

[0021] Figure 6 It is a timing chart for explaining the touch detection process and the writing process in the variable frame rate driving state and the pause driving state.

[0022] Figure 7 This is a timing diagram for explaining the occurrence of delay time.

[0023] Figure 8 This is a timing chart for explaining how to eliminate the delay time.

[0024] Description of Reference Numerals

[0025] 1…touch panel, 2…panel control unit, 3…host control unit, 4…active pen, 11…touch detection electrode, 21…timing control unit, 22…touch detection control unit, 31…host touch control unit, 32…host display control unit, 51…receiving unit, 52…storage unit, 53…write timing control unit, 54…sending unit, 55…drive status acquisition unit, 56…timing signal generating unit, 100…display device with touch panel, B…beacon signal, D…tilt and pressure signal, P…coordinate detection signal, Ts…timing signal. DETAILED DESCRIPTION

[0026] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same or equivalent parts in the drawings, and the description thereof will not be repeated. In addition, in order to make the description easier to understand, the configuration is simplified or schematically shown, or a part of the components is omitted in the accompanying drawings referred to below. In addition, the size ratios between the components shown in the drawings do not necessarily show the actual size ratios.

[0027] [Configuration of a display device with a touch panel]

[0028] Figure 1 The configuration of a display device 100 with a touch panel (hereinafter referred to as “display device 100 ”) according to the present embodiment will be described. Figure 1 It is a block diagram showing the functional configuration of the display device 100 according to the present embodiment.

[0029] like Figure 1 As shown, the display device 100 includes a touch panel 1, a panel control unit 2, and a host control unit 3. The touch panel 1 has a touch detection function of detecting a touch of an indicator such as a finger or an active pen 4 and detecting a touched position, and has a display function of displaying a video or an image. The touch panel 1 is configured as an in-cell type touch panel having a liquid crystal layer, for example. The panel control unit 2 performs control processing related to touch detection of the touch panel 1 and control processing related to display of the touch panel 1. The host control unit 3 performs control processing for the entire display device 100. The active pen 4 (stylus pen) transmits the user's touch operation to the touch panel 1 when held by the user.

[0030] like Figure 1 As shown, the touch panel 1 includes a plurality of touch detection electrodes 11, a drive circuit 12, a thin film transistor 13 and a plurality of pixel electrodes 14. Figure 1 In FIG. 1 , for ease of description, one touch detection electrode 11 and one pixel electrode 14 are described. The drive circuit 12 includes, for example, one or a plurality of integrated circuits.

[0031] Figure 2 FIG. 1 is a top view schematically showing the structure of the touch panel 1. Figure 2 As shown, the plurality of touch detection electrodes 11 are arranged in a matrix, for example. The drive circuit 12 includes a touch detection driver. The plurality of touch detection electrodes 11 and the drive circuit 12 (touch detection driver) are connected via touch signal lines 15 .

[0032] Figure 3 1 is a circuit diagram for explaining the connection relationship between the thin film transistor 13 and the pixel electrode 14. Figure 1) also includes a gate driver and a source driver. In addition, the gate driver of the driving circuit 12 is connected to the gate line 16. The source driver of the driving circuit 12 is connected to the source line 17. The gate electrode of the thin film transistor 13 is connected to the gate line 16, and the source electrode of the thin film transistor 13 is connected to the source line 17. In addition, the drain electrode of the thin film transistor 13 is connected to the pixel electrode 14. In addition, an electrostatic capacitor is formed between the pixel electrode 14 and the touch detection electrode 11. The touch detection electrode 11 is configured to be shared by a plurality of pixel electrodes 14 and function as a common electrode.

[0033] The gate driver of the drive circuit 12 sequentially supplies a gate signal (scanning signal) to each of the plurality of gate lines 16. In addition, the source driver of the drive circuit 12 supplies a source signal based on a video signal to each of the plurality of source lines 17. As a result, the thin film transistor 13 supplied with the gate signal is turned on, and the source signal is written to the pixel electrode 14. In addition, in the touch panel 1, a liquid crystal layer (not shown) is driven by an electric field generated by the pixel electrode 14 and the touch detection electrode 11 (common electrode), and a video is displayed.

[0034] like Figure 1 As shown, the host control unit 3 includes a host touch control unit 31 and a host display control unit 32. The host touch control unit 31 and the host display control unit 32 each include a processor that performs control processing. The host touch control unit 31 communicates with the panel control unit 2 and receives touch detection information from the panel control unit 2. The "touch detection information" includes, for example, information on the touch position of a finger or an active pen 4, and the inclination and pen pressure (pressure) of the active pen 4. In addition, the host display control unit 32 supplies (sends) a broadcast signal or a video signal obtained from a storage medium not shown in the figure to the panel control unit 2.

[0035] Here, the display device 100 is a display device that operates at a variable frame rate. The "variable frame rate" is achieved by changing the length of the pause period between the video input period and the pause period that constitute one frame. The "video input period" refers to the period during which a video signal is supplied from the host control unit 3 to the panel control unit 2, and the "pause period" refers to the period during which a video signal is not supplied from the host control unit 3 to the panel control unit 2. In addition, the host display control unit 32 (drive state determination unit) changes from a normal drive state (refer to the drive state determination unit) in which a pause period of a first predetermined length L1 is provided within one frame according to a setting operation of the user or the content of the video. Figure 4 ), a pause driving state in which a pause period of a second predetermined length L2 longer than the length L1 is provided within one frame (refer to Figure 6 ), and a variable frame rate driving state in which a pause period of varying length is set within one frame, and is determined as any one of the driving states. Figure 41 is a diagram for explaining an example of processing of the display device 100 in a normal driving state. Figure 5 2 is a diagram for explaining the contents of the writing process and the touch detection process. Figure 6 1 is a diagram for explaining an example of processing of the display device 100 in the suspended driving state. Figure 6 In FIG. 1 , the length of the pause period in the variable frame rate driving state is shown as L2, but the length of the pause period varies for each frame. Then, the host display control unit 32 sends information on the determined driving state to the panel control unit 2 .

[0036] like Figure 1 As shown, the active pen 4 is an indicator body that is touched by the touch panel 1 and is a pen having a function of communicating with the panel control unit 2. The active pen 4 includes a control unit 41, a sensor unit 42, and a communication unit 43. The communication unit 43 includes a communication interface that transmits and receives signals (communicates) with the panel control unit 2 via the touch detection electrode 11 of the touch panel 1. The sensor unit 42 includes a sensor that detects the pressure (pen pressure) of the active pen 4 on the touch panel 1, and a sensor that detects the inclination of the active pen 4. The control unit 41 includes a processor that performs control processing related to the communication with the active pen 4.

[0037] The control unit 41 communicates with the communication unit 43 at a predetermined timing ( Figure 4 The control unit 41 obtains the beacon signal B sent from the touch panel 1 during the period when the coordinate detection signal P ( Figure 4 4, 7, 10, and 13) and the inclination and pressure signal D ( Figure 4 In addition, the beacon signal B may also include identification information inherent to the touch panel 1. In this case, the control unit 41 identifies the touch panel 1 based on the obtained identification information, and sends the coordinate detection signal P and the inclination and pressure signal D at a prescribed timing corresponding to the identified touch panel 1. Then, the panel control unit 2 obtains the position where the active pen 4 detects the touch by detecting the position of the touch detection electrode 11 that receives the coordinate detection signal P. In addition, the panel control unit 2 obtains the information on the inclination of the active pen 4 and the information on the pressure (pen pressure) based on the inclination and pressure signal D.

[0038] (Composition of the panel control section)

[0039] like Figure 1As shown, the panel control unit 2 includes a timing control unit 21 and a touch detection control unit 22. The timing control unit 21 includes a processor that performs control processing related to the timing of the write processing in the touch panel 1 and the timing of the touch detection processing performed by the touch panel 1. In addition, the timing control unit 21 includes a receiving unit 51, a storage unit 52, a write timing control unit 53, a sending unit 54, a drive state acquisition unit 55, and a timing signal generation unit 56. In addition, the "write processing" refers to the processing of sending the video signal stored in the storage unit 52 to the touch panel 1, supplying the source signal (data signal) based on the video signal to the thin film transistor 13, and writing to the pixel electrode 14. In addition, as Figure 5 As shown, the “touch detection process” includes “finger touch detection process”, “sending beacon signal”, “receiving coordinate detection signal” and “receiving inclination and pressure signal”. The “finger touch detection process” is a process of detecting the electrostatic capacitance between the touch detection electrode 11 and the pixel electrode 14 that changes when an indicator such as a finger contacts or approaches the touch panel 1. The “sending beacon signal” is a process of sending a beacon signal B from the panel control unit 2 to the active pen 4. The “receiving coordinate detection signal” is a process of the panel control unit 2 receiving the coordinate detection signal P sent from the active pen 4 via the touch panel 1. The “receiving inclination and pressure signal” is a process of the panel control unit 2 receiving the inclination and pressure signal D sent from the active pen 4 via the touch panel 1.

[0040] In addition, if Figure 4 and Figure 5 As shown, in this embodiment, the timing control unit 21 divides the "write process" into 13 periods for execution per frame in the normal driving state, and divides the "touch detection process" into 13 periods for execution. That is, the timing control unit 21 performs the write process in 13 periods based on the video signal obtained from the host control unit 3 during the video input period.

[0041] like Figure 1 As shown, the receiving unit 51 includes a communication interface for receiving a video signal from the host control unit 3. The storage unit 52 includes a frame buffer for storing the video signal received by the receiving unit 51. The write timing control unit 53 (display control unit) includes a processor for determining the timing of writing processing. The sending unit 54 (display control unit) supplies the video signal stored in the storage unit 52 to the drive circuit 12 of the touch panel 1 according to the instruction from the write timing control unit 53. The drive status acquisition unit 55 obtains the information of the drive status from the host control unit 3. The timing signal generation unit 56 generates a timing signal (TSYNC; hereinafter referred to as "Ts") and supplies the timing signal Ts to the touch detection control unit 22. And, as Figure 4 As shown, the writing timing control unit 53 performs writing processing in the touch panel 1 at equal time intervals in synchronization with the timing signal Ts.

[0042] The touch detection control unit 22 includes a processor that performs touch detection processing through the touch panel 1. Figure 1 In the embodiment of the present invention, although the timing control unit 21 and the touch detection control unit 22 are described separately, it is not necessary to form the timing control unit 21 and the touch detection control unit 22 by separate hardware. That is, the functions of both the timing control unit 21 and the touch detection control unit 22 can be realized by one hardware. Figure 4 As shown, the touch detection control unit 22 obtains the timing signal Ts from the timing control unit 21 and performs touch detection processing at equal time intervals in synchronization with the timing signal Ts.

[0043] like Figure 5 As shown, the touch detection control unit 22 switches according to the instruction from the host touch control unit 31: the finger touch mode for detecting the touch of a pointer such as a finger without communicating with the active pen 4, and the pen touch mode for detecting the touch of the active pen 4 by communicating with the active pen 4 in addition to detecting the touch of the finger. Figure 5 , the contents of the processing in the finger touch mode and the contents of the processing in the pen touch mode executed every frame in the normal drive state are shown. Figure 5 The "periods T1 to T13" are respectively Figure 4 Corresponding to "1" to "13".

[0044] <Processing in Finger Touch Mode>

[0045] like Figure 5As shown, during period T2, "finger touch detection processing" is performed. Specifically, the following processing is performed: a driving signal is supplied to a part (for example, half) of the multiple touch detection electrodes 11 of the touch panel 1, and a detection signal is received from the touch detection electrode 11 supplied with the driving signal, and a touch of a finger or the like is detected based on the detection signal. In addition, during period T3, the following processing is performed: a driving signal is supplied to another part (for example, the remaining half) of the touch detection electrodes 11 of the touch panel 1, and a detection signal is received from the touch detection electrode 11 supplied with the driving signal, and a touch of a finger or the like is detected based on the detection signal. That is, during periods T2 and T3, touch detection is performed on all touch detection electrodes 11 of the touch panel 1. Then, at the end of period T3, a touch detection report is sent from the touch detection control unit 22 to the host control unit 3. During each of periods T4 and T5, T8 and T9, and T10 and T11, the same touch detection processing and sending of touch detection reports as during periods T2 and T3 are performed. That is, when the frame rate is 60 Hz, the touch detection report is sent at 240 Hz. In addition, during periods T1, T6, T7, T12, and T13, touch detection is not performed but writing is performed. As a result, the number of periods in the finger touch mode (the number of times the processing is performed) can be made consistent with the number of periods in the pen touch mode (the number of times the processing is performed). In addition, writing is also performed during periods T2 to T5 and T8 to T11.

[0046] <Processing in pen touch mode>

[0047] During the period T1, the touch detection control unit 22 transmits the beacon signal B to the active pen 4. During the periods T4, T7, T10, and T13, the coordinate detection signal P is transmitted from the active pen 4, and the coordinate detection signal P is obtained by the touch detection control unit 22 via the touch detection electrode 11. Thus, the touch detection control unit 22 obtains the touch position of the active pen 4 based on the position of the touch detection electrode 11 that detects the coordinate detection signal P. Then, the touch detection control unit 22 transmits the information of the touch position of the active pen 4 to the host control unit 3 as a touch detection report. In addition, during the periods T5, T6, T11, and T12, the inclination and pressure signal D is transmitted from the active pen 4, and the inclination and pressure signal D is obtained by the touch detection control unit 22 via the touch detection electrode 11. Thus, the touch detection control unit 22 obtains the information of the inclination of the active pen 4 and the information of the writing pressure (pressure). Then, the touch detection control unit 22 transmits the information of the inclination of the active pen 4 and the information of the writing pressure (pressure) to the host control unit 3 as a touch detection report. In the pen touch mode, the finger touch detection process is performed in the same manner as in the above-mentioned finger touch mode during the periods T2, T3, T8, and T9. That is, in the pen touch mode, not only the touch detection of the active pen 4 but also the touch detection of the finger etc. is performed. In addition, the writing process is performed in the periods T1 to T13.

[0048] <Processing in normal driving state>

[0049] Reference Figure 4 The processing in the normal driving state of the display device 100 is described. Figure 4 As shown, the writing process and the touch detection process are alternately performed in synchronization with the timing signal Ts. For example, the writing process is performed when the timing signal Ts becomes high (High), and the touch detection process is performed when the timing signal Ts becomes low (Low).

[0050] In detail, Figure 4 As shown, at time point t0, the video input period starts, and the writing process is performed. Then, at time point t1, the touch detection process is performed. Thereafter, after the suspension period starts at time point t2, the writing process and the touch detection process are also alternately performed in synchronization with the timing signal Ts. Then, at time point t3, a new video input period starts, and thereafter, the writing process and the touch detection process are also alternately performed.

[0051] <Processing in variable frame rate drive state and pause drive state>

[0052] Reference Figure 6 , the processing in the variable frame rate driving state and the suspended driving state of the display device 100 is described. Figure 6As shown, by setting the pause period L2 which is longer than the length L1, the frame rate is reduced in the variable frame rate driving state and the pause driving state compared with the normal driving state.

[0053] In addition, if Figure 6 As shown, during the video input period, the writing process and the touch detection process are performed alternately in synchronization with the timing signal Ts. In addition, during the period of length L1 in the pause period, the writing process and the touch detection process are performed alternately in synchronization with the timing signal Ts. Then, after the period of length L1 in the pause period, the touch detection process is performed at equal time intervals. As a result, even if the frame rate of the display is reduced, the frame rate related to touch detection will not be reduced.

[0054] Here, in this embodiment, when a new video signal is supplied during the pause period and a new video input period starts, the touch detection process being executed or the touch detection process to be executed next ( Figure 6 After the touch detection process (in which the touch detection process of period T7 is completed) is completed, the new video signal stored in the storage unit 52 is output to the drive circuit 12 in the display device 100, and the writing process of the touch panel 1 is performed by the data signal based on the new video signal. Specifically, when the new video input period starts, the timing control unit 21 detects the time point (the time point) at which the touch detection process being executed or the touch detection process to be executed next is completed based on the timing signal Ts. Figure 6 Then, the timing control unit 21 starts the touch detection process after the touch detection process ends ( Figure 6 According to this configuration, even when the frame rate changes, the new video signal stored in the storage unit 52 can be output to the drive circuit 12 in the display device 100 at the time point t14 when the touch detection process being executed or the touch detection process to be executed next ends, not in the middle of the touch detection process, and the write process of the touch panel 1 can be executed by the data signal based on the new video signal. As a result, the timing of the touch detection process can be matched with the timing of the write process.

[0055] In addition, in the present embodiment, when a new video input period starts, the timing control unit 21 performs a touch detection process in any one of the periods T1 to T13 ( Figure 6After the touch detection of the period T7 is completed, the writing process of the touch panel 1 is performed. In particular, in the case of the pen touch mode, when a new video input period starts, the timing control unit 21 performs any one of the following operations: sending of the beacon signal B being executed or sending of the beacon signal B to be executed next, receiving of the coordinate detection signal P being executed or receiving of the coordinate detection signal P to be executed next, or obtaining of the inclination and pressure signal D being executed or obtaining of the inclination and pressure signal D to be executed next ( Figure 6 After the coordinate detection signal P is acquired during period T7, the touch panel 1 is written. According to this configuration, the timing of writing can be advanced (the delay time can be prevented from being prolonged) compared to the case where the writing is performed after the touch detection process is performed in all periods T1 to T13.

[0056] In detail, Figure 6 In the example shown, at time point t10, the video input period starts and the write process is performed. Then, at time point t11, the touch detection process is performed. Thereafter, from the start of the pause period to time point t12 (a period of length L1), the write process and the touch detection process are performed alternately in synchronization with the timing signal Ts. Then, during the pause period (after time point t12 to time point t13), the write process is not performed, but the touch detection process is performed at equal time intervals. Thus, for example, within 1 frame period, in addition to the touch detection process during periods T1 to T13, the touch detection process during periods T1 to T6 is also performed.

[0057] Here, when the write process is performed at time point t13 in the touch detection process of period T7, the write process will be performed in the middle of the touch detection process, and the signals of the write process and the touch detection process in the touch panel (touch detection electrode) interfere with each other and cannot perform normal operations. For example, accurate touch detection cannot be performed, and the touch panel cannot be correctly displayed. In contrast, in the present embodiment, at time point t13, the write process is not performed, but the touch detection process of period T7 is completed. Then, at time point t14 after the time point of the touch detection process of period T7, the write process is performed by a data signal based on the video signal stored in the storage unit 52. Thereafter, at time point t15, the touch detection of the next period T8 of period T7 is performed. Thereafter, the write process and the touch detection process are performed alternately. As a result, the signals of the write process and the touch detection process do not interfere with each other, and the timing of the touch detection process can be matched with the timing of the write process.

[0058] <Processing related to elimination of delay time>

[0059] Next, refer to Figure 7 and Figure 8 The process related to eliminating the delay time of the display device 100 is described. Figure 7 It is a diagram for explaining the occurrence of delay time in the variable frame rate driving state. Figure 8 1 is a diagram for explaining elimination of the delay time in the pause drive state. The “delay time” refers to the period from the start time point of the video input period to the time point when the first writing process is performed based on the video signal stored in the storage unit 52 .

[0060] like Figure 7 As shown, in this embodiment, when a new video input period starts at the time point t21 of the pause period, the touch detection process being executed or the touch detection process to be executed next ( Figure 7 At time t22 when the touch detection process (in which the touch detection process of period T8) ends, the new video signal stored in the storage unit 52 is output to the drive circuit 12 in the display device 100 for writing. In this case, the period from time t21 to time t22 is the delay time, and the timing control unit 21 obtains the information of the delay time. Figure 8 The example shown shows that in the generated Figure 7 The state of changing from the variable frame rate driving state to the pause driving state under the state of the delay time shown. In addition, a period of control in the normal driving state may be set during the period of changing from the variable frame rate driving state to the pause driving state.

[0061] like Figure 8 As shown in FIG. 1 , when the information on the driving state obtained from the host control unit 3 (the driving state determined by the host control unit 3) is "suspended driving state", the timing control unit 21 suspends the touch detection process during the suspension period. Then, the timing control unit 21 makes the timing of the timing signal Ts coincide with the start time point ( Figure 8 Then, the timing control unit 21 performs the touch detection process and the writing process alternately based on the timing signal Ts synchronized with the start time point.

[0062] In detail, Figure 8As shown, the time point t31 when the video input period starts is offset from the time point t30 when the timing signal Ts becomes high (High). Furthermore, in the case of a suspension period and from the time point t32 when the last period T13 in the touch detection process ends to the time point t33 when a new video signal is supplied (the time point when the new video input period starts), the timing control unit 21 stops (suspends) the touch detection process. Then, after the time point t33 when the new video input period starts, the write process and the touch detection process are restarted. For example, at the time point t33, the timing signal Ts becomes high (High), and the write process is performed. In addition, at the time point t34 when the timing signal Ts becomes low (Low), the touch detection process is restarted. Thus, the period from the time point t32 to the time point t33 functions as a period for eliminating the delay time (delay elimination period), and the delay time is eliminated.

[0063] According to the above configuration, even if Figure 7 As shown in FIG. 1 , in the case where a delay time occurs from the start time point t21 of the video input period to the time point t22 at which the writing process is first performed during the video input period, as shown in FIG. Figure 8 As shown, the delay time can also be eliminated. In addition, in the variable frame rate driving state, since the length of the suspension period is not fixed, even if the touch detection is suspended in the variable frame rate driving state, the delay time may not be eliminated. On the other hand, according to the above-mentioned configuration, since the touch detection is suspended in the suspension driving state with a fixed length of the suspension period, the delay time can be eliminated more reliably. In addition, since the touch detection process is restarted after the delay time is eliminated, the period during which the touch detection is not performed can be shortened compared to the case where the touch detection process is continuously suspended in order to eliminate the delay time.

[0064] [Deformation, etc.]

[0065] The above-described embodiments are merely examples for implementing the present disclosure. Therefore, the present disclosure is not limited to the above-described embodiments, and the above-described embodiments can be appropriately modified and implemented within the scope of the present disclosure.

[0066] (1) In the above embodiment, an example is shown in which the display device is configured to perform two types of touch detection processing: touch detection processing by a finger or the like and touch detection processing using an active pen capable of communication, but the present disclosure is not limited thereto. That is, the display device may be configured to perform only touch detection processing by a finger or the like, or only touch detection processing using an active pen capable of communication.

[0067] (2) In the above embodiment, an example of performing touch detection processing 13 times per frame in a normal driving state is shown, but the present disclosure is not limited to this. That is, the touch detection processing may be performed less than 13 times per frame, or more than 14 times per frame. In addition, the number of times the finger touch detection processing, beacon signal transmission, coordinate detection signal reception, and inclination and pressure signal reception are performed per frame is not limited to the number of times shown in the example.

[0068] (3) In the above embodiment, in order to eliminate the delay time, the touch detection is performed during the pause period until the period T13 and then the touch detection process is suspended, but the present disclosure is not limited to this. That is, in order to eliminate the delay time, the touch detection process may be suspended before the touch detection process in the period T13 is performed during the pause period.

[0069] The above-mentioned display device with a touch panel and the method for controlling the display device with a touch panel can be described as follows.

[0070] The display device with a touch panel of the first structure is a display device with a touch panel that operates at a variable frame rate. The variable frame rate is achieved by changing the length of a pause period in a video input period and a pause period that constitute one frame. During the video input period, a video signal is supplied to the display device with the touch panel, and during the pause period, no video signal is supplied to the display device with the touch panel. The display device with the touch panel comprises: a touch panel including pixel electrodes; a control unit that controls display and touch detection performed by the touch panel; and a storage unit that stores the video signal. The control unit comprises: a touch detection control unit that controls the touch panel during the video input period. During and during the pause period, touch detection processing is performed by the touch panel; a display control unit, which performs a write process during the video input period, and the above-mentioned write process outputs the video signal stored in the storage unit to the touch panel, and writes a data signal based on the video signal to the pixel electrode; and a timing control unit, which causes the touch detection process and the write process to be performed alternately during the video input period, and during the pause period, the touch detection process is performed at least at equal time intervals, and the timing control unit starts at the video input period and performs the write process after the touch detection process being executed or the touch detection process to be executed next is completed (the first configuration).

[0071] Here, in the case where the frame rate drops, it is considered that not only the write process but also the touch detection process is suspended during the suspension period. However, in this case, since the number of touch detection processes per time will decrease, the responsiveness of the touch detection will decrease. Therefore, in the case where the frame rate drops, it is considered that the touch detection process is also performed during the suspension period, but when the time point (the starting time point during the video input period) when the new video signal is supplied is in the middle of the touch detection process, the touch detection process and the write process will be performed simultaneously in the touch panel. In this case, the signal related to the touch detection process and the signal related to the write process will interfere, and the touch detection process and the write process cannot be properly performed. In contrast, according to the above-mentioned first configuration, even in the case of a change in the frame rate, the video signal stored in the storage unit can be output to the touch panel and the write process of the touch panel can be performed after the touch detection process in execution or the touch detection process to be executed next is completed, not in the middle of the touch detection process. As a result, the timing of the touch detection process can be matched with the timing of the write process. According to this, even when control is performed using a variable frame rate, it is possible to detect a touch by a finger, a pen, or the like.

[0072] In the first configuration, the timing control unit may generate a timing signal for synchronizing the timing of executing the touch detection processing with the timing of executing the write processing. The touch detection control unit may execute the touch detection processing synchronized with the timing signal. The timing control unit may detect the time point when the touch detection processing being executed or the touch detection processing to be executed next ends based on the timing signal at the beginning of the video input period, and execute the write processing after this time point (the second configuration).

[0073] According to the second configuration, the time point at which the touch detection process being executed or the touch detection process to be executed next is completed can be easily detected based on the timing signal.

[0074] In the first or second configuration, it can also be configured to further include a driving state determining unit, which determines any one driving state from a normal driving state in which a pause period of a first specified length is provided within one frame, a pause driving state in which a pause period of a second specified length longer than the first specified length is provided within one frame, and a variable frame rate driving state in which a pause period of varying length is provided within one frame. It can also be configured that, when a delay time is generated from the time point when the video input period starts to the time point when the write processing is first performed and the driving state determined by the driving state determining unit is the pause driving state, the timing control unit pauses the touch detection processing during the pause period, and restarts the touch detection processing after the start time point of a new video input period after the touch detection processing is paused (third configuration).

[0075] According to the third configuration, even if a delay time occurs from the start time point of the video input period to the time point when the write process is first performed during the video input period, the delay time can be eliminated. In addition, in the variable frame rate driving state, since the length of the pause period is not fixed, even if the touch detection process is paused in the variable frame rate driving state, the delay time may not be eliminated. On the other hand, according to the third configuration, the touch detection process is paused in the pause driving state in which the length of the pause period is fixed, so the delay time can be eliminated more reliably. In addition, since the touch detection process is restarted after the delay time is eliminated, the period during which the touch detection process is not performed can be shortened compared to the case where the touch detection process is continuously paused in order to eliminate the delay time.

[0076] In any one of the first to third configurations, the touch detection control unit may obtain the touch position after executing the touch detection process a specified number of times, and the timing control unit may execute the write process after any one of the touch detection processes of the specified number of times being executed or any one of the touch detection processes of the specified number of times to be executed next is completed when the video input period starts (the fourth configuration).

[0077] According to the fourth configuration, compared with the case where the touch detection process is executed a predetermined number of times and then the write process to the touch panel is performed, the timing of performing the write process can be advanced (the delay time can be prevented from being prolonged).

[0078] In any one of the first to fourth configurations, it may be that there is also a communication unit that communicates with the active pen, or it may be configured that the touch detection control unit executes a sending process of sending a beacon signal to the active pen and executes an acquisition process of obtaining a coordinate detection signal from the active pen. It may also be configured that the timing control unit, at the beginning of the video input period, causes the write process to be executed after any one of the beacon signal sending processes being executed or the beacon signal sending processes to be executed next, or any one of the coordinate detection signal acquisition processes being executed or the coordinate detection signal acquisition processes to be executed next is completed (the fifth configuration).

[0079] According to the fifth configuration, compared with the case where the touch panel write process is performed after both the transmission of the beacon signal and the acquisition of the coordinate detection signal are executed, the timing of performing the write process can be advanced (the delay time can be prevented from being prolonged).

[0080] The sixth configuration is a method for controlling a display device with a touch panel that operates at a variable frame rate, the touch panel including pixel electrodes, the variable frame rate being achieved by varying the length of a pause period in a video input period and a pause period that constitute one frame, the video signal being supplied to the display device with the touch panel during the video input period, and not being supplied to the display device with the touch panel during the pause period, the method for controlling a display device with a touch panel comprising the following steps: storing the video signal in a storage unit; alternatingly executing touch detection processing and writing processing during the video input period, the touch detection processing being performed by the touch panel, the writing processing outputting the video signal stored in the storage unit to the touch panel, and writing a data signal based on the video signal to the pixel electrode; executing the touch detection processing at least at equal time intervals during the pause period; and executing the write processing at the beginning of the video input period after the touch detection processing being executed or the touch detection processing to be executed next is completed (the sixth configuration).

[0081] According to the sixth configuration, similarly to the above-described first configuration, even when control is performed using a variable frame rate, it is possible to detect a touch by a finger, a pen, or the like.

Claims

1. A display device with a touch panel, operating at a variable frame rate, characterized in that: The variable frame rate is achieved by changing the length of the idle period between the video input period and the idle period constituting one frame. During the video input period, a video signal is supplied to the display device with a touch panel, and during the pause period, a video signal is not supplied to the display device with a touch panel. The above-mentioned display device with a touch panel comprises: A touch panel comprising pixel electrodes; a control unit that controls display and touch detection performed by the touch panel; as well as a storage unit storing the video signal, The control unit includes: a touch detection control unit that performs touch detection processing via the touch panel during the video input period and the pause period; a display control unit that performs a write process during the video input period, wherein the write process outputs the video signal stored in the storage unit to the touch panel and writes a data signal based on the video signal to the pixel electrode; and a timing control unit that causes the touch detection process and the writing process to be performed alternately during the video input period, and causes the touch detection process to be performed at least at equal time intervals during the pause period, The timing control unit causes the writing process to be executed after the touch detection process being executed or the touch detection process to be executed next is completed when the video input period starts. The display device with a touch panel further includes a driving state determination unit, and the driving state determination unit determines any one of the driving states from a normal driving state in which the pause period of the first prescribed length is provided within one frame, a pause driving state in which the pause period of the second prescribed length longer than the first prescribed length is provided within one frame, and a variable frame rate driving state in which the pause period of a variable length is provided within one frame. The timing control unit When a delay time occurs from the time point when the video input period starts to the time point when the write process is first executed and the drive state determined by the drive state determination unit is the suspended drive state, the touch detection process is suspended during the suspended period. After the touch detection process is stopped, the touch detection process is restarted at a start time of a new video input period.

2. The display device with a touch panel according to claim 1, wherein: The timing control unit generates a timing signal for synchronizing the timing of executing the touch detection process with the timing of executing the writing process. The touch detection control unit performs touch detection processing in synchronization with the timing signal. The timing control unit detects a time point at which the touch detection process being executed or the touch detection process to be executed next ends based on the timing signal when the video input period starts, and executes the writing process after the time point.

3. The display device with a touch panel according to claim 1 or 2, wherein: The touch detection control unit obtains the touch position after executing the touch detection process for a predetermined number of times. The timing control unit causes the writing process to be executed when a video input period starts, after any one of the predetermined number of touch detection processes being executed or any one of the predetermined number of touch detection processes to be executed next is completed.

4. The display device with a touch panel according to claim 1 or 2, wherein: It also includes a communication unit for communicating with the active pen. The touch detection control unit performs a transmission process of transmitting a beacon signal to the active pen, and performs an acquisition process of acquiring a coordinate detection signal from the active pen. The timing control unit executes the write processing after the execution of the beacon signal sending processing or any one of the beacon signal sending processing to be executed next, or the execution of the coordinate detection signal acquisition processing or any one of the coordinate detection signal acquisition processing to be executed next is completed when the video input period starts.

5. A method for controlling a display device with a touch panel, wherein the display device with a touch panel operates at a variable frame rate, the touch panel includes pixel electrodes, and the method for controlling a display device with a touch panel is characterized in that: The variable frame rate is achieved by changing the length of the idle period between the video input period and the idle period constituting one frame. During the video input period, a video signal is supplied to the display device with a touch panel, and during the pause period, a video signal is not supplied to the display device with a touch panel. The control method of the display device with a touch panel comprises the following steps: storing the video signal in a storage unit; During the video input period, touch detection processing and writing processing are alternately performed, wherein the touch detection processing is performed by a touch panel, and the writing processing outputs the video signal stored in the storage unit to the touch panel, and writes a data signal based on the video signal to the pixel electrode; During the suspension period, the touch detection process is executed at least at equal time intervals; as well as At the beginning of the video input period, the above-mentioned writing process is executed after the touch detection process being executed or the touch detection process to be executed next is completed. The control method of the display device with a touch panel further comprises: A step of determining any one of the driving states from among a normal driving state in which the pause period of a first predetermined length is provided within one frame, a pause driving state in which the pause period of a second predetermined length longer than the first predetermined length is provided within one frame, and a variable frame rate driving state in which the pause period of a variable length is provided within one frame; When a delay time occurs from the time point when the video input period starts to the time point when the write process is first executed and the drive state determined by the determination step is the stop drive state, a step of stopping the touch detection process during the stop period; as well as A step of restarting the touch detection process after the touch detection process is stopped and after a start time point of a new video input period.

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