JP5710449B2 - Display device, driving circuit, driving method, and electronic apparatus - Google Patents

Description

  The present disclosure relates to a display panel having a function of detecting a touch by an external proximity object, a driving circuit and a driving method used for such a display panel, and an electronic apparatus including such a display panel.

  In recent years, a touch detection device called a touch panel is mounted on a display panel such as a liquid crystal display panel, or the touch panel and the display panel are integrated to display various button images on the display panel. A display panel that can input information as a substitute for a formula button has attracted attention. A display panel having such a touch detection function does not require an input device such as a keyboard, a mouse, or a keypad, and therefore, the use of the display panel tends to expand in addition to computers and portable information terminals such as mobile phones. is there.

  There are several types of touch panel methods such as an optical type, a resistance type, and a capacitance type. For example, Patent Document 1 proposes a capacitive touch panel in which a plurality of electrodes extending in one direction are arranged so as to intersect each other. In this touch panel, each electrode is connected to a control circuit, and an external proximity object is detected by supplying an excitation current from the control circuit.

  Further, for example, in Patent Document 2, a display common electrode originally provided in a display panel is used as one of a pair of touch sensor electrodes, and the other electrode (touch detection electrode) is used in common. There has been proposed a so-called in-cell type display panel arranged so as to intersect with an electrode. Some so-called on-cell type display panels in which a touch panel is formed on the display surface of the display panel have been proposed.

JP-T-2006-511879 JP 2009-258182 A

  By the way, in recent years, display panels have been increased in definition and size. For example, when the display panel and the touch panel are operated in synchronization, the proportion of the writing period of the pixel signal in one frame period increases with the increase in horizontal lines. Time will be shortened. Therefore, it is desired that touch panels perform touch detection in a short time while maintaining the original touch detection accuracy.

  The present disclosure has been made in view of such problems, and an object thereof is to provide a display panel, a driving circuit, a driving method, and an electronic apparatus that can perform touch detection in a short time while suppressing reduction in touch detection accuracy. It is to provide.

A display device according to the present disclosure includes a display panel in which a plurality of display elements are formed , a plurality of drive electrodes, one or a plurality of touch detection electrodes, and a plurality of frames formed along at least one side of a frame portion of the display panel. DC signal supply wiring, a signal generation part, and the drive part formed in at least one side of the frame part of a display panel are provided. One or a plurality of touch detection electrodes form a capacitance between each drive electrode. The signal generator generates a plurality of DC signals having different voltages and outputs the signals to a plurality of DC signal supply lines . The drive unit selectively applies a plurality of DC signals supplied from the plurality of DC signal supply wirings to each drive electrode.

The drive circuit of the present disclosure includes a plurality of DC signal supply wirings formed along at least one side of the frame portion of the display panel, a signal generation unit, and a drive unit formed on at least one side of the frame portion of the display panel. I have. The signal generator generates a plurality of DC signals having different voltages and outputs the signals to a plurality of DC signal supply lines . The drive unit selectively applies a plurality of DC signals supplied from a plurality of DC signal supply wirings to each of a plurality of drive electrodes forming an electrostatic capacitance with one or a plurality of touch detection electrodes. To do.

The driving method according to the present disclosure generates a plurality of DC signals having different voltages and outputs the DC signals to a plurality of DC signal supply wirings formed along at least one side of the frame portion of the display panel. A plurality of DC signals supplied from a plurality of DC signal supply wirings are selectively applied to each of a plurality of drive electrodes that form a capacitance between them.

An electronic apparatus according to the present disclosure includes the display device, and includes, for example, a television device, a digital camera, a personal computer, a video camera, or a mobile terminal device such as a mobile phone.

In the display device , the drive circuit, the drive method, and the electronic apparatus according to the present disclosure, a drive signal is applied to the plurality of drive electrodes, and the drive signal is transmitted to the touch detection electrode via the capacitance. At that time, a drive signal is applied by selectively applying a plurality of DC signals.

According to the display device , the drive circuit, the drive method, and the electronic apparatus of the present disclosure, a plurality of direct current signals are selectively applied to the drive electrodes, so that the touch detection accuracy is reduced and reduced. Touch detection can be performed in time.

It is a figure for demonstrating the basic principle of the touch detection system in the display panel of this indication, and is a figure showing the state which the finger | toe does not touch or adjoin. It is a figure for demonstrating the basic principle of the touch detection system in the display panel of this indication, and is a figure showing the state which the finger contacted or adjoined. It is a figure for demonstrating the basic principle of the touch detection system in the display panel of this indication, and is a figure showing an example of the waveform of a drive signal and a touch detection signal. 3 is a block diagram illustrating a configuration example of a display panel according to an embodiment of the present disclosure. FIG. FIG. 5 is a block diagram illustrating a configuration example of a selection switch unit illustrated in FIG. 4. FIG. 5 is a cross-sectional view illustrating a schematic cross-sectional structure of the display device with a touch detection function illustrated in FIG. 4. FIG. 5 is a circuit diagram illustrating a pixel arrangement in the liquid crystal display device illustrated in FIG. 4. FIG. 5 is a perspective view illustrating a configuration example of a drive electrode and a touch detection electrode in the touch detection device illustrated in FIG. 4. FIG. 5 is a schematic diagram illustrating an operation example of touch detection scanning in the display panel illustrated in FIG. 4. FIG. 5 is a schematic diagram illustrating an operation example of display scanning and touch detection scanning in the display panel illustrated in FIG. 4. It is a block diagram showing the example of 1 structure of the drive electrode driver which concerns on 1st Embodiment. FIG. 5 is a schematic diagram illustrating a mounting example of the display panel illustrated in FIG. 4. 6 is a timing waveform chart illustrating an operation example of the display panel according to the first embodiment. FIG. FIG. 6 is a timing waveform diagram illustrating an example of a touch detection operation in the display panel according to the first embodiment. It is a schematic diagram showing the example of mounting of the display panel concerning a comparative example. It is a block diagram showing the example of 1 structure of the display panel which concerns on another comparative example. FIG. 17 is a schematic diagram illustrating a mounting example of the display panel illustrated in FIG. 16. FIG. 17 is a timing waveform chart illustrating an operation example of the display panel illustrated in FIG. 16. FIG. 5 is a characteristic diagram illustrating a characteristic example of the display panel illustrated in FIG. 4. FIG. 11 is a schematic diagram illustrating an operation example of a display panel according to a modification example of the first embodiment. FIG. 10 is a timing waveform diagram illustrating an operation example of a touch detection operation of a display panel according to a modification of the first embodiment. FIG. 16 is a timing waveform chart illustrating an operation example of a touch detection operation of a display panel according to another modification of the first embodiment. It is a block diagram showing the example of 1 structure of the drive electrode driver which concerns on the other modification of 1st Embodiment. FIG. 24 is a truth table illustrating an operation example of the drive electrode driver illustrated in FIG. 23. It is a block diagram showing the example of 1 structure of the drive electrode driver which concerns on the other modification of 1st Embodiment. It is a block diagram showing the example of 1 structure of the drive electrode driver which concerns on the other modification of 1st Embodiment. 27 is a truth table illustrating an operation example of the drive electrode driver illustrated in FIG. 26. It is a block diagram showing the example of 1 structure of the drive part which concerns on 2nd Embodiment. FIG. 10 is a timing waveform diagram illustrating an operation example of a display panel according to a second embodiment. It is a characteristic view showing the example of a characteristic of the display panel which concerns on 2nd Embodiment. It is a block diagram showing the example of 1 structure of the display panel which concerns on the modification of 2nd Embodiment. FIG. 32 is a timing waveform chart illustrating an operation example of the display panel illustrated in FIG. 31. FIG. 14 is a characteristic diagram illustrating another characteristic example of the display panel according to the second embodiment. 1 is a perspective view illustrating an appearance configuration of a television device to which a display panel according to an embodiment is applied. It is sectional drawing showing the schematic sectional structure of the display device with a touch detection function which concerns on a modification.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.
1. 1. Basic principle of capacitive touch detection First Embodiment 3. FIG. Second embodiment 4. Application examples

<1. Basic Principle of Capacitive Touch Detection>
First, the basic principle of touch detection in the display panel of the present disclosure will be described with reference to FIGS. This touch detection method is embodied as a capacitive touch sensor. For example, as shown in FIG. 1A, a pair of electrodes (drives) arranged opposite to each other with a dielectric D interposed therebetween. A capacitive element is configured using the electrode E1 and the touch detection electrode E2). This structure is expressed as an equivalent circuit shown in FIG. The drive element E1, the touch detection electrode E2, and the dielectric D constitute a capacitive element C1. One end of the capacitive element C1 is connected to an AC signal source (drive signal source) S, and the other end P is grounded via a resistor R and also connected to a voltage detector (touch detection circuit) DET. When an AC rectangular wave Sg (FIG. 3B) having a predetermined frequency (for example, about several kHz to several tens of kHz) is applied from the AC signal source S to the drive electrode E1 (one end of the capacitive element C1), the touch detection electrode E2 ( An output waveform (touch detection signal Vdet) as shown in FIG. 3A appears at the other end P) of the capacitive element C1.

  In a state where the finger is not in contact (or close proximity), as shown in FIG. 1, a current I0 corresponding to the capacitance value of the capacitive element C1 flows along with charging / discharging of the capacitive element C1. The potential waveform at the other end P of the capacitive element C1 at this time is, for example, a waveform V0 in FIG. 3A, which is detected by the voltage detector DET.

  On the other hand, when the finger is in contact (or close proximity), the capacitive element C2 formed by the finger is added in series to the capacitive element C1, as shown in FIG. In this state, currents I1 and I2 flow in accordance with charging and discharging of the capacitive elements C1 and C2, respectively. The potential waveform at the other end P of the capacitive element C1 at this time is, for example, a waveform V1 in FIG. 3A, and this is detected by the voltage detector DET. At this time, the potential at the point P is a divided potential determined by the values of the currents I1 and I2 flowing through the capacitive elements C1 and C2. For this reason, the waveform V1 is smaller than the waveform V0 in the non-contact state. The voltage detector DET compares the detected voltage with a predetermined threshold voltage Vth, and determines that it is in a non-contact state if it is equal to or higher than this threshold voltage, and determines that it is in a contact state if it is less than the threshold voltage. To do. In this way, touch detection is possible.

<2. First Embodiment>
[Configuration example]
(Overall configuration example)
FIG. 4 illustrates a configuration example of the display panel according to the first embodiment. The display panel 1 is a so-called in-cell type display panel in which a liquid crystal display device and a capacitive touch detection device are integrated.

  The display panel 1 includes a control unit 11, a gate driver 12, a source driver 13, a selection switch unit 14, a drive signal generation unit 15, a drive electrode driver 16, a display device 10 with a touch detection function, and a touch. And a detection unit 40.

  Based on the video signal Vdisp, the control unit 11 supplies control signals to the gate driver 12, the source driver 13, the drive electrode driver 16, and the touch detection unit 40 so that these operate in synchronization with each other. It is a circuit to control.

  The gate driver 12 has a function of sequentially selecting one horizontal line as a display driving target of the display device 10 with a touch detection function based on a control signal supplied from the control unit 11. Specifically, the gate driver 12 generates a scanning signal Vscan based on the control signal supplied from the control unit 11, and the scanning signal Vscan is transmitted to the TFT element Tr of the pixel Pix via the scanning signal line GCL. By applying to the gate, one row (one horizontal line) of the pixels Pix formed in a matrix on the liquid crystal display device 20 of the display device with a touch detection function 10 is sequentially selected as a display drive target.

  The source driver 13 generates and outputs a pixel signal Vsig based on the video signal and the source driver control signal supplied from the control unit 11. Specifically, as will be described later, the source driver 13 uses a plurality of (three in this example) subpixels SPix of the liquid crystal display device 20 of the display device 10 with a touch detection function from a video signal for one horizontal line. A pixel signal Vsig obtained by time-division multiplexing the pixel signal Vpix is generated and supplied to the selection switch unit 14. The source driver 13 generates a switch control signal Vsel (VselR, VselG, VselB) necessary for separating the pixel signal Vpix multiplexed on the pixel signal Vsig, and supplies the switch control signal Vsel to the selection switch unit 14 together with the pixel signal Vsig. It also has a function to do. This multiplexing is performed in order to reduce the number of wires between the source driver 13 and the selection switch unit 14.

  The selection switch unit 14 separates the pixel signal Vpix time-division multiplexed on the pixel signal Vsig based on the pixel signal Vsig and the switch control signal Vsel supplied from the source driver 13, and the liquid crystal of the display device 10 with a touch detection function. This is supplied to the display device 20.

  FIG. 5 illustrates a configuration example of the selection switch unit 14. The selection switch unit 14 includes a plurality of switch groups 17. In this example, each switch group 17 has three switches SWR, SWG, and SWB, one ends of which are connected to each other and the pixel signal Vsig is supplied from the source driver 13, and the other end is a display with a touch detection function. The pixel 10 is connected to three subpixels SPix (R, G, B) related to the pixel Pix via the pixel signal line SGL of the liquid crystal display device 20 of the device 10. The three switches SWR, SWG, SWB are controlled to be turned on / off by a switch control signal Vsel (VselR, VselG, VselB) supplied from the source driver 13, respectively. With this configuration, the selection switch unit 14 switches the three switches SWR, SWG, SWB sequentially in a time division manner according to the switch control signal Vsel to turn them on so that the pixel signal Vsig is multiplexed. It functions to separate the signals Vpix (VpixR, VpixG, VpixB). The selection switch unit 14 supplies these pixel signals Vpix to the three subpixels SPix.

  The drive signal generator 15 generates two DC drive signals VcomDC and VcomH and supplies them to the drive electrode driver 16. In this example, the DC drive signal VcomDC is a DC signal having a voltage of 0V, and the DC drive signal VcomH is a DC signal having a voltage VH higher than 0V.

  The drive electrode driver 16 is a circuit that supplies a drive signal Vcom to drive electrodes COML (described later) of the display device with a touch detection function 10 based on a control signal supplied from the control unit 11. Specifically, the drive electrode driver 16 applies the DC drive signal VcomDC to the drive electrode COML in the display operation. In the touch detection operation, the drive electrode driver 16 generates a pulse signal from the DC drive signals VcomDC and VcomH, applies the pulse signal to the drive electrode COML related to the touch detection operation, and applies to the other drive electrodes COML. The DC drive signal VcomDC is applied. At this time, as will be described later, the drive electrode driver 16 drives the drive electrode COML for each block (drive electrode block B described later) including a predetermined number of drive electrodes COML.

  The display device 10 with a touch detection function is a display device with a built-in touch detection function. The display device with a touch detection function 10 includes a liquid crystal display device 20 and a touch detection device 30. As will be described later, the liquid crystal display device 20 is a device that performs scanning by sequentially scanning one horizontal line at a time in accordance with a scanning signal Vscan supplied from the gate driver 12. The touch detection device 30 operates based on the basic principle of the capacitive touch detection described above, and outputs a touch detection signal Vdet. As will be described later, the touch detection device 30 performs touch detection by sequentially scanning in accordance with the drive signal Vcom supplied from the drive electrode driver 16.

  The touch detection unit 40 detects the touch of the touch detection device 30 based on the touch detection control signal supplied from the control unit 11 and the touch detection signal Vdet supplied from the touch detection device 30 of the display device 10 with a touch detection function. This is a circuit that detects presence / absence and obtains the coordinates in the touch detection area when there is a touch. The touch detection unit 40 includes an LPF (Low Pass Filter) unit 42, an A / D conversion unit 43, a signal processing unit 44, a coordinate extraction unit 45, and a detection timing control unit 46. The LPF unit 42 is a low-pass analog filter that removes a high frequency component (noise component) included in the touch detection signal Vdet supplied from the touch detection device 30, extracts the touch component, and outputs it. A resistor R for applying a DC potential (for example, 0 V) is connected between each of the input terminals of the LPF unit 42 and the ground. In place of the resistor R, for example, a switch may be provided, and a DC potential (0 V) may be applied by turning on the switch at a predetermined time. The A / D converter 43 is a circuit that samples each analog signal output from the LPF unit 42 and converts it into a digital signal at a timing synchronized with the pulse signal of the drive signal Vcom. The signal processing unit 44 is a logic circuit that detects the presence or absence of a touch on the touch detection device 30 based on the output signal of the A / D conversion unit 43. The coordinate extraction unit 45 is a logic circuit that calculates touch panel coordinates when touch detection is performed in the signal processing unit 44. The detection timing control unit 46 controls these circuits to operate in synchronization.

(Display device with touch detection function 10)
Next, a configuration example of the display device 10 with a touch detection function will be described in detail.

  FIG. 6 illustrates an example of a cross-sectional structure of a main part of the display device 10 with a touch detection function. The display device with a touch detection function 10 includes a pixel substrate 2, a counter substrate 3 disposed opposite to the pixel substrate 2, and a liquid crystal layer 6 interposed between the pixel substrate 2 and the counter substrate 3. It has.

  The pixel substrate 2 includes a TFT substrate 21 as a circuit substrate, a drive electrode COML, and a pixel electrode 22. The TFT substrate 21 functions as a circuit substrate on which various electrodes and wirings (pixel signal lines SGL and scanning signal lines GCL described later), thin film transistors (TFTs), and the like are formed. The TFT substrate 21 is made of, for example, glass. A drive electrode COML is formed on the TFT substrate 21. The drive electrode COML is an electrode for supplying a common voltage to a plurality of pixels Pix (described later). The drive electrode COML functions as a common drive electrode for a liquid crystal display operation and also functions as a drive electrode for a touch detection operation. An insulating layer 23 is formed on the drive electrode COML, and a pixel electrode 22 is formed thereon. The pixel electrode 22 is an electrode for supplying a pixel signal for display and has translucency. The drive electrode COML and the pixel electrode 22 are made of, for example, ITO (Indium Tin Oxide).

  The counter substrate 3 includes a glass substrate 31, a color filter 32, and a touch detection electrode TDL. The color filter 32 is formed on one surface of the glass substrate 31. The color filter 32 is configured by periodically arranging, for example, three color filter layers of red (R), green (G), and blue (B), and each display pixel has R, G, and B color filters. Three colors are associated as one set. A touch detection electrode TDL is formed on the other surface of the glass substrate 31. The touch detection electrode TDL is an electrode made of, for example, ITO and having translucency. A polarizing plate 35 is disposed on the touch detection electrode TDL.

  The liquid crystal layer 6 functions as a display function layer, and modulates the light passing therethrough according to the state of the electric field. This electric field is formed by a potential difference between the voltage of the drive electrode COML and the voltage of the pixel electrode 22. For the liquid crystal layer 6, a liquid crystal in a transverse electric field mode such as FFS (fringe field switching) or IPS (in-plane switching) is used.

  An alignment film is provided between the liquid crystal layer 6 and the pixel substrate 2 and between the liquid crystal layer 6 and the counter substrate 3, and an incident side polarizing plate is provided on the lower surface side of the pixel substrate 2. Although not shown, the illustration is omitted here.

  FIG. 7 illustrates a configuration example of a pixel structure in the liquid crystal display device 20. The liquid crystal display device 20 has a plurality of pixels Pix arranged in a matrix. Each pixel Pix includes three subpixels SPix. These three subpixels SPix are arranged so as to correspond to the three colors (RGB) of the color filter 32 shown in FIG. The sub-pixel SPix has a TFT element Tr and a liquid crystal element LC. The TFT element Tr is composed of a thin film transistor. In this example, the TFT element Tr is composed of an n-channel MOS (Metal Oxide Semiconductor) TFT. The source of the TFT element Tr is connected to the pixel signal line SGL, the gate is connected to the scanning signal line GCL, and the drain is connected to one end of the liquid crystal element LC. The liquid crystal element LC has one end connected to the drain of the TFT element Tr and the other end connected to the drive electrode COML.

  The sub-pixel SPix is connected to another sub-pixel SPix belonging to the same row of the liquid crystal display device 20 by the scanning signal line GCL. The scanning signal line GCL is connected to the gate driver 12, and the scanning signal Vscan is supplied from the gate driver 12. The subpixel SPix is connected to another subpixel SPix belonging to the same column of the liquid crystal display device 20 by the pixel signal line SGL. The pixel signal line SGL is connected to the selection switch unit 14, and the pixel signal Vpix is supplied from the selection switch unit 14.

  Further, the sub-pixel SPix is connected to another sub-pixel SPix belonging to the same row of the liquid crystal display device 20 by the drive electrode COML. The drive electrode COML is connected to the drive electrode driver 16, and a drive signal Vcom is supplied from the drive electrode driver 16.

  With this configuration, in the liquid crystal display device 20, the gate driver 12 drives the scanning signal lines GCL so as to perform line sequential scanning in a time division manner, whereby one horizontal line is sequentially selected, and the pixels Pix belonging to the one horizontal line are selected. On the other hand, when the source driver 13 and the selection switch unit 14 supply the pixel signal Vpix, display is performed for each horizontal line.

  FIG. 8 is a perspective view illustrating a configuration example of the touch detection device 30. The touch detection device 30 includes a drive electrode COML provided on the pixel substrate 2 and a touch detection electrode TDL provided on the counter substrate 3. The drive electrode COML has a strip-like electrode pattern extending in the left-right direction in the figure. When performing the touch detection operation, as will be described later, a pulse signal of the drive signal Vcom is sequentially supplied to each electrode pattern for each block (drive electrode block B described later) including a predetermined number of drive electrodes COML. Sequential scanning driving is performed in a time division manner. The touch detection electrode TDL has a strip-like electrode pattern extending in a direction orthogonal to the extending direction of the electrode pattern of the drive electrode COML. Each electrode pattern of the touch detection electrode TDL is connected to an input of the LPF unit 42 of the touch detection unit 40. The electrode patterns intersecting with each other by the drive electrode COML and the touch detection electrode TDL form a capacitance at the intersection.

  With this configuration, in the touch detection device 30, when the drive electrode driver 16 applies the drive signal Vcom to the drive electrode COML, the touch detection signal Vdet is output from the touch detection electrode TDL so that touch detection is performed. It has become. That is, the drive electrode COML corresponds to the drive electrode E1 in the basic principle of touch detection shown in FIGS. 1 to 3, the touch detection electrode TDL corresponds to the touch detection electrode E2, and the touch detection device 30 is Touch is detected according to this basic principle. As shown in FIG. 8, the electrode patterns intersecting each other constitute a capacitive touch sensor in a matrix. Therefore, by scanning the entire touch detection surface of the touch detection device 30, it is possible to detect the position where the contact or proximity of the external proximity object has occurred.

  The drive electrode driver 16 drives the drive electrode COML for each block (drive electrode block B) including a predetermined number of drive electrodes COML to perform touch detection scanning.

  FIG. 9 schematically shows the touch detection scanning. FIG. 9 shows an operation of supplying the drive signal Vcom to each of the drive electrode blocks B1 to B20 when the touch detection surface is composed of 20 drive electrode blocks B1 to B20. In FIG. 9, the drive electrode block B indicated by hatching indicates that a pulse signal generated from the DC drive signals VcomDC and VcomH is supplied, and the other drive electrode block B is supplied with the DC drive signal VcomDC. Indicates that

  The drive electrode driver 16 applies a drive signal Vcom for each drive electrode block B to the drive electrode COML. The drive electrode block B is set to a width (for example, about 5 mm) corresponding to the size of the user's finger, for example. As shown in FIG. 9, the drive electrode driver 16 sequentially selects the drive electrode block B that is the target of the touch detection operation, and applies a pulse signal to the drive electrode COML that belongs to the drive electrode block B. Scan over all drive electrode blocks B. In this example, for convenience of explanation, the number of drive electrode blocks B is set to 20. However, the present invention is not limited to this.

  FIG. 10 schematically shows display scanning and touch detection scanning. In the display panel 1, the gate driver 12 drives the scanning signal lines GCL so as to scan the signal lines GCL in a time-division manner, thereby performing display scanning Scan, and the drive electrode driver 16 sequentially selects the drive electrode block B. By driving, touch detection scanning Scan is performed. In this example, the touch detection scan Scant is performed at a scanning speed twice that of the display scan Scand. As described above, in the display panel 1, by making the scanning speed of touch detection faster than the display scanning, it is possible to immediately respond to the touch by the external proximity object, and to improve the response characteristic to the touch detection. It has become. However, the present invention is not limited to this. For example, the touch detection scanning Scan may be performed at a scanning speed that is twice or more that of the display scanning Scan, or at a scanning speed that is twice or less that of the display scanning Scan. It may be performed.

(Drive electrode driver 16)
FIG. 11 shows a configuration example of the drive electrode driver 16. The drive electrode driver 16 includes a scanning control unit 51, a touch detection scanning unit 52, and a driving unit 530. The drive unit 530 has 20 drive units 53 (1) to 53 (20). Hereinafter, when referring to any one of the 20 drive units 53 (2) to 53 (20), the drive unit 53 is simply used.

  The scanning control unit 51 supplies a control signal to the touch detection scanning unit 52 based on the control signal supplied from the control unit 11. The scan control unit 51 also has a function of supplying the drive unit 530 with a Vcom selection signal VCOMSEL for instructing which of the DC drive signal VcomDC and the DC drive signal VcomH is supplied to the drive electrode COML. Have.

  The touch detection scanning unit 52 includes a shift register, and generates a scanning signal St for selecting the driving electrode COML to which the DC driving signal VcomH is applied. Specifically, the touch detection scanning unit 52 generates a plurality of scanning signals St each corresponding to each drive electrode block B based on the control signal supplied from the scanning control unit 51 as described later. For example, when the touch detection scanning unit 52 supplies a high level signal to the kth driving unit 53 (k) as the kth scanning signal St (k), the driving unit 53 (k) The DC drive signal VcomH is applied to the plurality of drive electrodes COML belonging to the second drive electrode block B (k).

  Based on the scanning signal St supplied from the touch detection scanning unit 52 and the Vcom selection signal VCOMSEL supplied from the scanning driving unit 51, the driving unit 530 receives the direct current driving signal VcomDC or direct current supplied from the driving signal generation unit 15. The drive signal VcomH is applied to the drive electrode COML. The drive units 53 are provided one by one corresponding to the output signal of the touch detection scanning unit 52, and apply the drive signal Vcom to the corresponding drive electrode block B.

  The drive unit 53 includes an AND circuit 54, an inverter 55, buffers 56 and 57, and switches SW1 and SW2. The AND circuit 54 generates and outputs a logical product (AND) of the scanning signal St supplied from the touch detection scanning unit 52 and the Vcom selection signal VCOMSEL supplied from the scanning control unit 51. The inverter 55 generates and outputs an inverted logic of the output signal of the AND circuit 54. The buffer 56 has a function of amplifying the signal supplied from the AND circuit 54 to an amplitude level at which the switch SW1 can be turned on / off. The switch SW1 is controlled to be turned on / off based on a signal supplied from the buffer 56. The DC drive signal VcomH is supplied to one end and the other end is connected to a plurality of drive electrodes COML constituting the drive electrode block B. Has been. The buffer 57 has a function of amplifying the signal supplied from the inverter 55 to an amplitude level at which the switch SW2 can be controlled on and off. The switch SW2 is ON / OFF controlled based on a signal supplied from the buffer 57, and a DC drive signal VcomDC is supplied to one end and the other end is connected to the other end of the switch SW1.

  With this configuration, when the scanning signal St is at a high level, the driving unit 53 outputs the DC driving signal VcomH as the driving signal Vcom when the Vcom selection signal VCOMSEL is at a high level, and the Vcom selection signal VCOMSEL is at a low level. At this time, the DC drive signal VcomDC is output as the drive signal Vcom. The drive unit 53 outputs the DC drive signal VcomDC as the drive signal Vcom when the scanning signal St is at a low level. The drive unit 53 supplies the drive signal Vcom output in this way to a plurality of drive electrodes COML constituting the drive electrode block B corresponding to the drive unit 53.

(Example of mounting display panel 1)
FIG. 12 schematically shows a mounting example of the display panel 1. The control unit 11, the source driver 13, and the drive signal generation unit 15 are mounted on the pixel substrate 2 as COG (Chip On Glass). The selection switch section 14 is formed using a TFT element in the vicinity of the display area Ad on the TFT substrate 21.

  The gate driver 12 (12A, 12B) is formed on the TFT substrate 21 using a TFT element. In this example, the gate driver 12 is arranged on the upper side (12A) and the lower side (12B) of the pixel substrate 2 in FIG. 12, and drives the pixels Pix (not shown) arranged in a matrix in the display area Ad from both sides. Can be done.

  The drive electrode driver 16 (16A, 16B) is formed on the TFT substrate 21 using a TFT element. In this example, the drive electrode driver 16 is disposed on the upper side (16A) and the lower side (16B) of the pixel substrate 2 in FIG. 12, and is driven by the direct current from the drive signal generation unit 15 via the wiring LDC having a thick pattern. The signal VcomDC is supplied, and the DC drive signal VcomH is also supplied through the wiring LH having a thick pattern. The drive electrode drivers 16A and 16B can drive each of the plurality of drive electrode blocks B arranged in parallel from both sides.

  Further, the touch detection unit 40 is mounted on the flexible printed circuit board T and connected to each of the plurality of touch detection electrodes TDL arranged in parallel.

  Here, the drive signal generation unit 15 corresponds to a specific example of “signal generation unit” in the present disclosure. The DC drive signals VcomDC and VcomH correspond to a specific example of “DC signal” in the present disclosure. The drive electrode driver 16 corresponds to a specific example of a “drive unit” in the present disclosure. The DC drive signal VcomDC corresponds to a specific example of “first DC signal” in the present disclosure, and the DC drive signal VcomH corresponds to a specific example of “second DC signal” in the present disclosure. The source driver 13 and the selection switch unit 14 correspond to a specific example of “pixel signal generation unit” in the present disclosure. The pixel signal line SGL corresponds to a specific example of “signal line” in the present disclosure.

[Operation and Action]
Next, the operation and action of the display panel 1 of the present embodiment will be described.

(Overview of overall operation)
First, with reference to FIG. 4, an overview of the overall operation of the display panel 1 will be described. Based on the video signal Vdisp, the control unit 11 supplies control signals to the gate driver 12, the source driver 13, the drive electrode driver 16, and the touch detection unit 40 so that these operate in synchronization with each other. To control.

  The gate driver 12 supplies the scanning signal Vscan to the liquid crystal display device 20, and sequentially selects one horizontal line that is a display driving target. The source driver 13 generates a pixel signal Vsig obtained by multiplexing the pixel signal Vpix and a switch control signal Vsel corresponding to the pixel signal Vsig, and supplies the generated signal to the selection switch unit 14. The selection switch unit 14 separates and generates the pixel signal Vpix based on the pixel signal Vsig and the switch control signal Vsel, and supplies the pixel signal Vpix to each sub-pixel SPix constituting one horizontal line. The drive signal generator 15 generates DC drive signals VcomDC and VcomHC. The drive electrode driver 16 applies the drive signal Vcom for each drive electrode block B. Specifically, the drive electrode driver 16 applies the DC drive signal VcomDC to the drive electrode COML in the display operation. In the touch detection operation, a pulse signal is generated and applied from the DC drive signals VcomDC and VcomH to the drive electrode COML related to the touch detection operation, and the DC drive signal VcomDC is applied to the other drive electrodes COML. Apply. The display device with a touch detection function 10 performs a display operation and a touch detection operation, and outputs a touch detection signal Vdet from the touch detection electrode TDL.

  The touch detection unit 40 detects a touch based on the touch detection signal Vdet. Specifically, the LPF unit 42 removes a high frequency component (noise component) included in the touch detection signal Vdet, extracts the touch component, and outputs it. The A / D converter 43 converts the analog signal output from the LPF unit 42 into a digital signal. The signal processing unit 44 detects the presence / absence of a touch on the display device 10 with a touch detection function based on the output signal of the A / D conversion unit 43. The coordinate extraction unit 45 obtains the touch panel coordinates when touch detection is performed in the signal processing unit 44. The detection timing control unit 46 controls the LPF unit 42, the A / D conversion unit 43, the signal processing unit 44, and the coordinate extraction unit 45 to operate in synchronization.

(Detailed operation)
Next, detailed operation of the display panel 1 will be described.

  13A and 13B show examples of timing waveforms of the display panel 1. FIG. 13A shows the waveform of the scanning signal Vscan, FIG. 13B shows the waveform of the pixel signal Vsig, and FIG. 13C shows the switch control signal Vsel. (D) shows the waveform of the pixel signal Vpix, (E) shows the waveform of the Vcom selection signal VCOMSEL, (F) shows the waveform of the drive signal Vcom, and (G) shows the touch detection signal Vdet. Waveform is shown.

  In the display panel 1, in each horizontal period (1H), a touch detection period Pt in which the touch detection operation is performed and a writing period Pw in which the pixel signal Vpix is written in the display operation are provided. In the touch detection operation, the drive electrode driver 16 sequentially applies a pulse signal generated from the DC drive signals VcomDC and VcomH to the drive electrode COML related to the touch detection operation for each drive electrode block B by touch detection. Scanning is performed, and the touch detection unit 40 detects a touch based on the touch detection signal Vdet output from the touch detection electrode TDL. In the display operation, the gate driver 12 sequentially applies the scanning signal Vscan to the scanning signal line GCL, and the source driver 13 and the selection switch unit 14 apply pixels to each sub-pixel SPix constituting the selected horizontal line. Write signal Vpix. Details will be described below.

  First, at timing t1, one horizontal period (1H) starts and a touch detection period Pt starts.

  First, the scanning control unit 51 of the drive electrode driver 16 changes the voltage of the Vcom selection signal VCOMSEL from the low level to the high level at the timing t1 (FIG. 13E). Thereby, in the drive electrode driver 16, in the k-th drive unit 53 (k) related to the touch detection operation, the switch SW1 is turned on and the switch SW2 is turned off, and the DC drive signal VcomH changes the switch SW1. Then, it is applied as the drive signal Vcom (B (k)) to the drive electrode COML constituting the corresponding kth drive electrode block B (k) (FIG. 13F). As a result, the drive signal Vcom (B (k)) changes from the low level (0 V) to the high level (voltage VH). This drive signal Vcom (B (k)) is transmitted to the touch detection electrode TDL via the electrostatic capacitance, and the touch detection signal Vdet changes (FIG. 13G).

  Next, the A / D conversion unit 43 of the touch detection unit 40 A / D converts the output signal of the LPF unit 42 to which the touch detection signal Vdet is input at the sampling timing ts (FIG. 13G). As will be described later, the signal processing unit 44 of the touch detection unit 40 performs touch detection based on the A / D conversion results collected in a plurality of horizontal periods.

  In the drive units 53 other than the drive unit 53 (k), the switch SW1 is turned off and the switch SW2 is turned on during the period from the timing t1 to the timing t2, and the DC drive signal VcomDC is switched to the switch SW1. The voltage is applied to the drive electrode COML constituting the corresponding drive electrode block B via SW2 (FIG. 13F). Thereby, for example, the drive signals Vcom (B (k-1)) and Vcom (B (k + 1)) are maintained at a low level (VcomDC).

  Next, the scanning control unit 51 of the drive electrode driver 16 changes the voltage of the Vcom selection signal VCOMSEL from the high level to the low level at the timing t2 (FIG. 13E). As a result, in the drive electrode driver 16, in the drive unit 53 (k), the switch SW1 is turned off and the switch SW2 is turned on, and the DC drive signal VcomDC is passed through the switch SW2 to the corresponding drive electrode block. A drive signal Vcom (B (k)) is applied to the drive electrode COML constituting B (k) (FIG. 13F).

  At this time, the charge charged in the drive electrode COML of the drive electrode block B (k) moves to another drive electrode block B via the switch SW2 of the drive unit 53 (k) after the timing t2. As shown in FIG. 13F, the drive signal Vcom (Vcom (B (k-1)), Vcom (B (k)), Vcom (B (k + 1)), etc.) slightly increases ( Waveform portion W1). Then, the drive signal generator 15 sinks this electric charge, so that these drive signals Vcom converge to the voltage level (0 V) of the DC drive signal VcomDC.

  Next, at the timing t3, the touch detection period Pt ends and the writing period Pw starts.

  First, at timing t3, the gate driver 12 applies the scanning signal Vscan to the scanning signal line GCL (n) of the nth row related to the display operation, and the scanning signal Vscan (n) is changed from the low level to the high level. It changes (FIG. 13 (A)). As a result, the gate driver 12 selects one horizontal line that is the target of the display operation.

  Then, the source driver 13 supplies the pixel voltage VR for the red sub-pixel SPix to the selection switch unit 14 as the pixel signal Vsig (FIG. 13B), and the period during which the pixel voltage VR is supplied A switch control signal VselR that is at a high level is generated at (FIG. 13C). Then, the selection switch unit 14 separates the pixel voltage VR supplied from the source driver 13 from the pixel signal Vsig by turning on the switch SWR during a period when the switch control signal VselR is at a high level. VpixR is supplied to the red sub-pixel SPix through the pixel signal line SGL (FIG. 13D). Since the pixel signal line SGL is in a floating state after the switch SWR is turned off, the voltage of the pixel signal line SGL is held (FIG. 13D).

  Similarly, the source driver 13 supplies the pixel voltage VG for the green sub-pixel Spix to the selection switch unit 14 together with the corresponding switch control signal VselG (FIGS. 13B and 13C), and the selection switch unit 14 separates the pixel voltage VG from the pixel signal Vsig based on the switch control signal VselG, and supplies it as the pixel signal VpixG to the green sub-pixel SPix via the pixel signal line SGL (FIG. 13D )).

  Thereafter, similarly, the source driver 13 supplies the pixel voltage VB for the blue sub-pixel Spix to the selection switch unit 14 together with the corresponding switch control signal VselB (FIGS. 13B and 13C) and selects the pixel voltage VB. Based on the switch control signal VselB, the switch unit 14 separates the pixel voltage VB from the pixel signal Vsig, and supplies it as the pixel signal VpixB to the blue subpixel SPix via the pixel signal line SGL (FIG. 13). (D)).

  Next, the gate driver 12 changes the scanning signal Vscan (n) of the scanning signal line GCL in the nth row from the high level to the low level at timing t4 (FIG. 13A). Thereby, the sub-pixel Spix of one horizontal line related to the display operation is electrically disconnected from the pixel signal line SGL. Thus, the writing period Pw ends.

  At timing t5, one horizontal period (1H) ends and a new one horizontal period (1H) starts.

  Thereafter, by repeating the above-described operation, the display panel 1 performs a display operation on the entire display surface by line-sequential scanning, and scans each drive electrode block B as shown below, thereby detecting the touch detection surface. The entire touch detection operation is performed.

  14A and 14B show an example of the operation of touch detection scanning. FIG. 14A shows the waveform of the Vcom selection signal VCOMSEL, FIG. 14B shows the waveform of the scanning signal St, and FIG. 14C shows the waveform of the drive signal Vcom. (D) shows the waveform of the touch detection signal Vdet. In this figure, for convenience of explanation, the transient behavior (rise time tr, fall time tf, etc.) when the signal voltage transitions is omitted.

  As shown in FIG. 14, the drive electrode driver 16 sequentially applies the DC drive signal VcomH to the corresponding drive electrode block B based on the scanning signal St (FIG. 14B) generated by the touch detection scanning unit 52. By doing so (FIG. 14C), touch detection scanning is performed. At this time, the drive electrode driver 16 applies a pulse signal generated from the DC drive signals VcomDC and VcomH to the drive electrode block B that is the target of the touch detection operation over a predetermined plurality of horizontal periods (FIG. 14). (C)). The touch detection unit 40 samples the touch detection signal Vdet based on the pulse signal in each one horizontal period, and after the sampling in the last horizontal period of the predetermined plurality of horizontal periods is finished, the signal processing unit 44. However, based on the plurality of sampling results, the presence / absence of a touch on the region corresponding to the drive electrode block B is detected. As described above, since touch detection is performed based on a plurality of sampling results, it is possible to statistically analyze the sampling results, and to suppress deterioration of the S / N ratio due to variations in the sampling results. And the accuracy of touch detection can be increased.

  In the display panel 1, the drive signal generation unit 15 supplies the DC drive signals VcomDC and VcomH to the drive electrode driver 16 via the wirings LDC and LH, and the drive electrode driver 16 uses the drive signal Vcom based on these signals. Is generated. Therefore, for example, when the drive electrode driver 16 applies the DC drive signal VcomH (pulse signal) to the drive electrode block B that is the target of the touch detection operation, the drive signal generation unit 15 has already applied the voltage VH to the wiring LH. Therefore, only the drive electrode block B needs to be driven. Thereby, in the display panel 1, the transition time (for example, rise time tr) of the drive signal Vcom can be shortened as will be described below in comparison with some comparative examples.

  In addition, by shortening the transition time of the drive signal Vcom in this way, it becomes possible to cope with higher definition and larger size of the display panel 1. Specifically, for example, when the display panel 1 has a high definition, the proportion of the writing period of the pixel signal in one frame period increases with the increase in the number of horizontal lines. It becomes difficult to secure the width touch detection time Pt. In the display panel 1, as described above, since the transition time of the drive signal Vcom (pulse signal) can be shortened, the touch detection time Pt can be shortened. It will be possible to respond to.

  Next, the operation of the present embodiment will be described in comparison with some comparative examples.

(Comparative Example 1)
First, the display panel 1Q according to Comparative Example 1 will be described. The display panel 1Q is different from the case of the present embodiment (FIG. 12) in that the drive electrode driver 16 is mounted as a COG together with the control unit 11 and the like.

  FIG. 15 schematically shows a mounting example of the display panel 1Q. As shown in FIG. 15, the drive electrode driver 16 is mounted as a COG together with the control unit 11, the source driver 13, and the drive signal generation unit 15, and a plurality of drive electrode blocks B arranged in parallel with each other and a long wiring Connected via L. The drive electrode driver 16 supplies, for example, a drive signal Vcom as shown in FIG. 14C to each drive electrode block B through the wiring L.

  In the display panel 1Q according to the first comparative example, the drive electrode driver 16 mounted as a COG directly drives each drive electrode block B via the long wiring L. As shown in FIG. 15, the number of wirings L is the same as the number of drive electrode blocks B. Therefore, the width of each wiring L becomes narrow and the wiring resistance increases. Thereby, when the drive electrode driver 16 supplies the drive signal Vcom (pulse signal) as shown in FIG. 14C to each drive electrode block B, the time constant of the wiring L is large. The signal rise time tr and fall time tf increase, and the pulse waveform may be crushed. In this case, since the crushed pulse signal is transmitted to the touch detection electrode TDL and is output as the touch detection signal Vdet, the accuracy of touch detection may be reduced.

  On the other hand, in the display panel 1 according to the present embodiment, as shown in FIG. 12, the drive electrode driver 16 (16A, 16B) is formed on the TFT substrate 21 in the vicinity of the display area Ad using a TFT element. Has been. The drive signal generator 15 supplies the drive electrode driver 16 with the DC drive signal VcomDC through the thick wiring LDC and the DC drive signal VcomH through the thick wiring LH. Generates a drive signal Vcom (pulse signal) as shown in FIG. 14C based on the DC drive signals VcomDC and VcomH supplied in this way, and supplies the drive signal to the drive electrode block B. That is, since the wirings LDC and LH are formed thick and transmit a direct current signal, the display panel 1 can reduce the possibility that the pulse waveform of the drive signal Vcom is crushed by the time constant of the wirings LDC and LH. it can.

(Comparative Example 2)
Next, a display panel 1R according to Comparative Example 2 will be described. In the display panel 1R, unlike the case of the present embodiment (FIG. 12), the drive signal generator generates an AC drive signal.

  FIG. 16 illustrates a configuration example of the display panel 1R. The display panel 1R includes a drive signal generation unit 15R and a control unit 11R. The drive signal generation unit 15R generates a DC drive signal VcomDC and an AC drive signal VcomAC and supplies them to the drive electrode driver 16. The drive electrode driver 16 supplies the drive signal Vcom to the drive electrode block B based on the DC drive signal VcomDC and the AC drive signal VcomAC as in the case of the above embodiment. In addition to the function of the control unit 11, the control unit 11R has a function of supplying a control signal for instructing the transition timing of the AC drive signal VcomAC to the drive signal control unit 15R.

  FIG. 17 schematically illustrates a mounting example of the display panel 1R. As illustrated in FIG. 17, the drive signal generation unit 15 </ b> R is mounted as a COG on the pixel substrate 2 together with the control unit 11 and the source driver 13. The drive electrode driver 16 is supplied with the direct current drive signal VcomDC from the drive signal generator 15R through the wiring LDC having a thick pattern, and is also supplied with the alternating current drive signal VcomAC through the wiring LAC having a thick pattern. That is, in the display panel 1R, the wiring time constant is reduced by forming the wiring LAC thick.

  18A and 18B show examples of timing waveforms of the display panel 1R, where FIG. 18A shows the waveform of the AC drive signal VcomAC, FIG. 18B shows the waveform of the DC drive signal VcomDC, and FIG. 18C shows the scan signal Vscan. (D) shows the waveform of the pixel signal Vsig, (E) shows the waveform of the switch control signal Vsel, (F) shows the waveform of the pixel signal Vpix, and (G) shows the Vcom selection signal VCOMSEL. (H) shows the waveform of the drive signal Vcom, and (I) shows the waveform of the touch detection signal Vdet.

  In the drive electrode driver 16 according to the second comparative example, as illustrated in FIG. 18, the scanning control unit 51 has a pulse width (timing t11 to t14) wider than the pulse width of the AC driving signal VcomAC (time t12 to t13). The Vcom selection signal VCOMSEL having the time (1) is generated. Then, each drive unit 53 applies the pulse waveform portion of the AC drive signal VcomAC to the drive electrode block B that is the target of the touch detection drive during the period in which the Vcom selection signal VCOMSEL is at a high level (FIG. 18H). ).

  In the display panel 1R according to the second comparative example, as illustrated in FIG. 17, the drive signal generation unit 15R mounted as a COG sends an AC drive signal VcomAC to the drive electrode driver 16 via the long wiring LAC. Supply. Unlike the display panel 1Q according to the comparative example 1 (FIG. 15), the wiring LAC is formed thick, so that the wiring resistance can be reduced. However, since the wiring LAC transmits the AC drive signal VcomAC, the transition time of the pulse signal may be increased due to the wiring capacitance of the wiring LAC.

  FIG. 19 shows characteristic examples of the rise time tr and the fall time tf of the drive signal Vcom in the display panel 1R according to the comparative example 2 and the display panel 1 according to the present embodiment.

  Thus, in the display panel 1R according to the comparative example 2, when the drive signal generation unit 15R applies the AC drive signal VcomAC to the drive electrode block B that is the target of the touch detection operation, the drive signal block 15R applies to the drive electrode block B. In addition, since it is necessary to drive the wiring LAC, the rise time tr and the fall time tf may be long.

  On the other hand, in the display panel 1, the drive signal generation unit 15 supplies the DC drive signals VcomDC and VcomH to the drive electrode driver 16 via the wirings LDC and LH, and the drive electrode driver 16 performs a pulse based on these signals. The signal is generated. Therefore, for example, when the drive signal generation unit 15 applies the DC drive signal VcomH to the drive electrode block B that is the target of the touch detection operation, the voltage VH is already applied to the wiring LH. Only the electrode block B needs to be driven, and the rise time tr can be shortened.

  In the display panel 1R, since the signal in the thickly formed wiring LAC is an AC signal (AC drive signal VcomAC), the AC component is one of the touch detection electrodes TDL provided in parallel in the display area Ad. There is a risk that it will be transmitted to the outermost touch detection electrode TDL as noise N1 through parasitic capacitance or the like (FIG. 17). This parasitic capacitance becomes larger when the wiring LAC for reducing the wiring resistance is formed thick. When noise is transmitted to the touch detection electrode TDL in this way, touch detection is performed based on the touch detection signal Vdet on which the noise is superimposed, and thus the accuracy of touch detection may be reduced.

  On the other hand, in the display panel 1 according to the present embodiment, as shown in FIG. 12, the signals in the two thickly formed wirings LDC and LH are both DC signals (DC drive signals VcomDC and VcomH). The possibility that the signals of the wirings LDC and LH are transmitted as noise to the touch detection electrodes TDL via parasitic capacitance or the like can be reduced. Thereby, in the display panel 1, a possibility that the precision of touch detection may fall can be reduced.

[effect]
As described above, in the present embodiment, the drive signal generation unit generates two DC drive signals, and the drive electrode driver arranged in the vicinity of the drive electrode block generates a drive signal based on them. The drive signal transition time can be shortened, and each drive electrode block can be driven in a shorter time.

  In this embodiment, since the transition time of the drive signal is shortened, the possibility that the pulse waveform of the drive signal is crushed can be reduced, and the decrease in the accuracy of touch detection can be suppressed.

  In this embodiment, since the drive signal generation unit supplies a DC drive signal to the drive electrode driver via the wiring, the signal of these wirings is generated as noise to the touch detection electrode. The risk of transmission can be reduced, and a decrease in accuracy of touch detection can be suppressed.

[Modification 1-1]
In the above embodiment, touch detection is performed every time each horizontal line is displayed. However, the present invention is not limited to this, and instead, for example, touch detection is performed every time a plurality of horizontal lines are displayed. May be. Specifically, for example, the display surface may be divided into a plurality of regions (partial display regions) similarly to the touch detection surface, and the touch detection operation may be performed for each display operation in each partial display region. Hereinafter, an example in which the display surface is divided into 20 partial display areas A1 to A20 will be described in detail.

  FIG. 20 schematically shows the operation of the display panel 1B according to the present modification, where (A) shows the touch detection operation and (B) shows the display operation. In this example, 20 touch detection periods Pt and 20 display periods Pd are alternately arranged in one frame period (1F).

  First, in the first touch detection period Pt, the touch detection operation for the drive electrode blocks B1 and B2 is performed, and in the subsequent display period Pd, the display operation (write operation) for a plurality of horizontal lines in the partial display area A1 is performed. . In the next touch detection period Pt, the touch detection operation for the drive electrode blocks B3 and B4 is performed, and in the subsequent display period Pd, the display operation (writing operation) for the plurality of horizontal lines in the partial display area A2 is performed. . Thereafter, similarly, the touch detection operation and the display operation are alternately performed.

  FIG. 21 illustrates a touch detection operation in the touch detection period Pt of the display panel 1B. In the touch detection period Pt, the drive electrode driver 16 first applies the DC drive signals VcomDC and VcomH alternately for a predetermined number of times to the drive electrode block B (k) (FIG. 21A). This drive signal Vcom is transmitted to the touch detection electrode TDL via the electrostatic capacitance, and the touch detection signal Vdet changes (FIG. 21B). The A / D conversion unit 43 of the touch detection unit 40 performs A / D conversion on the output signal of the analog LPF unit 42 to which the touch detection signal Vdet is input at the sampling timing ts synchronized with these pulse signals (FIG. 21 ( B)). Then, the signal processing unit 44 performs touch detection in the drive electrode block B (k) based on these A / D conversion results.

  Thereafter, the drive electrode driver 16 applies the DC drive signals VcomDC and VcomH alternately to the drive electrode block B (k + 1) a predetermined number of times in the same manner (FIG. 21A), and the touch detection unit 40 Based on the touch detection signal Vdet, touch detection in the drive electrode block B (k + 1) is performed.

  In the example shown in FIG. 21, in the final predetermined period of the touch detection period Pt, the drive electrode driver 16 applies the DC drive signal VcomDC to the drive signal blocks B (k) and B (k + 1). Is applied. As a result, even when a phenomenon such as the waveform portion W1 shown in FIG. 13 occurs, it is possible to secure time until the drive signal Vcom converges to the voltage level (0 V) of the DC drive signal VcomDC.

  In the above embodiment, the drive signal generator 15 generates two DC drive signals VcomDC and VcomH, and the drive electrode driver 16 selectively applies them to the drive electrode block B. For example, the drive signal generation unit generates three DC drive signals VcomDC, VcomH, and VcomL, and the drive electrode driver selectively selects them for the drive electrode block B. You may apply. Here, the DC drive signal VcomL is a DC signal having a voltage VL lower than 0V. In this case, the display panel according to the present modification can perform a touch detection operation as shown in FIG. 22, for example.

[Modification 1-2]
In the above embodiment, the touch detection scanning unit 52 of the drive electrode driver 16 is configured using a shift register. However, the present invention is not limited to this. For example, the touch detection scanning unit 52 may be configured using a decoder. Also good. This will be described in detail below.

  FIG. 23 illustrates a configuration example of a main part of the drive electrode driver 16C according to the present modification. The drive electrode driver 16C includes a decoder 62 and a scanning control unit 61. The decoder 62 is a 5-bit decoder and, as shown by using the truth table in FIG. 24, 20 drives based on the 5-bit input code DI (DI4 (MSB) to DI0 (LSB)). One of the electrode blocks B1 to B20 can be selected. Based on the control signal supplied from the control unit 11, the scanning control unit 61 supplies a 5-bit code DI to the decoder 62 and supplies a Vcom selection signal VCOMSEL to the drive unit 530. is there.

  Thus, by configuring the drive electrode driver 16C using the decoder 62, the drive electrode block B can be sequentially driven in an arbitrary order during the touch detection scanning. Specifically, for example, it is also possible to perform touch detection scanning by driving while skipping like drive electrode blocks B1, B3, B5,.

  Note that the drive electrode driver according to the present modification is not limited to the configuration shown in FIG. 23. Instead, the drive electrode driver may be configured as shown in FIG. That is, the final stage circuit 64 of the decoder 62 shown in FIG. 23 and the logical product circuit 54 of the drive unit 53 may be combined to make a simpler configuration. In this example, by providing the inverter 67 and the AND circuits 68 and 69, all the final stage circuits 64 can be eliminated, and the circuit scale can be reduced.

  In the above description, one of the 20 drive electrode blocks B1 to B20 is selected based on the input code DI. However, the present invention is not limited to this. For example, a plurality of drive electrode blocks You may comprise so that it may also have the function to select B simultaneously. The example in this case will be described in detail below.

  FIG. 26 illustrates a configuration example of the drive electrode driver 16E according to this modification. The drive electrode driver 16E has two operation modes: an operation mode M1 for selecting one of the 20 drive electrode blocks B1 to B20, and an operation mode M2 for selecting two simultaneously.

  The drive electrode driver 16E includes a scan control unit 71 and OR circuits 78 and 79. The scanning control unit 71 has a function of outputting a mode selection signal EN in addition to the function of the scanning control unit 61. When the mode selection signal EN is at the L level, the drive electrode driver 16E operates in the operation mode M1. That is, in this case, the OR circuits 78 and 79 in which the L level is input to one terminal do not make sense from the viewpoint of the logic operation. Therefore, the configuration of the drive electrode driver 16E is shown in FIG. This is equivalent to the configuration of the drive electrode driver 16D. When the mode selection signal EN is at the H level, the outputs of the OR circuits 78 and 79 are forcibly set to the high level, and the setting of the bit DI0 that is the LSB bit of the input code DI is ignored. As shown in the truth table in FIG. 27, two drive electrode blocks B can be selected using the upper 4 bits (DI4 to DI1) of the 5-bit input code DI.

<3. Second Embodiment>
Next, the display panel 7 according to the second embodiment will be described. In the present embodiment, in the touch detection period Pt, the drive electrode block B that is not subject to the touch detection operation is floated. That is, the display panel 7 is configured using the drive electrode driver 18 having the drive unit 73 that can float the drive electrode block B. Other configurations are the same as those of the first embodiment (FIG. 4). In addition, the same code | symbol is attached | subjected to the component substantially the same as the display panel 1 concerning the said 1st Embodiment, and description is abbreviate | omitted suitably.

  FIG. 28 illustrates a configuration example of the drive unit 73 according to the present embodiment. Here, the k-th drive unit 73 (k) will be described, but the other drive units have the same configuration.

  The drive unit 73 includes an OR circuit 72 and AND circuits 73 and 74. The OR circuit 72 generates and outputs a logical product of the scanning signal St supplied from the touch detection scanning unit 52 and the impedance control signal ZSEL. Here, as will be described later, the impedance control signal ZSEL is a logic signal that becomes L level only during the touch detection period Pt and becomes H level during other periods. The impedance control signal ZSEL may be generated by, for example, the scanning control unit 51 or may be generated by another circuit. The logical product circuit 73 generates a logical product of the output signal of the logical product circuit 54 and the output signal of the logical sum circuit 72 and supplies the logical product to the buffer 56. The logical product circuit 74 generates a logical product of the output signal of the inverter 55 and the output signal of the logical sum circuit 72 and supplies the logical product to the buffer 57.

  With this configuration, when the scanning signal St and the impedance control signal ZSEL are both at the L level, the driving unit 73 turns off both the switches SW1 and SW2 to thereby connect the driving unit 73 to the driving unit 73. The electrode block B is brought into a floating state. Further, when at least one of the scanning signal St and the impedance control signal ZSEL is at the H level, the driving unit 73 performs an operation equivalent to that of the driving unit 53 according to the first embodiment.

  FIG. 29 shows an example of the timing waveform of the display panel 7, (A) shows the waveform of the scanning signal Vscan, (B) shows the waveform of the pixel signal Vsig, and (C) shows the switch control signal Vsel. (D) shows the waveform of the pixel signal Vpix, (E) shows the waveform of the Vcom selection signal VCOMSEL, (F) shows the waveform of the impedance control signal ZSEL, and (G) shows the drive signal Vcom. (H) shows the waveform of the touch detection signal Vdet.

  As shown in FIG. 29, the impedance control signal ZSEL is at a low level during the period from the timing t21 to t22 (touch detection period Pt) (FIG. 29F). At this time, a pulse signal generated from the DC drive signals VcomDC and VcomH is applied to the drive electrode block B (k) subject to the touch detection operation, as in the case of the first embodiment (FIG. 29 (G)). On the other hand, the drive electrode blocks B (k−1) and B (k + 1) that are not subject to the touch detection operation are driven by the drive units 73 (k−1) and 73 (k + 1) connected to these drive electrode blocks. Since the switches SW1 and SW2 in the parentheses are in the off state, the switches SW1 and SW2 are in the floating state (waveform portion W2).

  Thus, in the display panel 7, unlike the display panel 1 according to the first embodiment (the waveform portion W1 in FIG. 13), the drive electrode COML of the drive electrode block B (k) is charged. Since the charge does not move to another drive electrode block B after timing t22, the drive signal Vcom converges to 0V in a short time. Thus, in the display panel 7, the voltage of the drive signal Vcom immediately converges to 0 V in the writing period Pw, so that the possibility of affecting the display image quality can be reduced.

  In the display panel 7, the drive electrode driver 18 puts the drive electrode block B that is not subject to the touch detection operation into a floating state in the touch detection period Pt. That is, the load of the drive signal generation unit 15 is only the drive electrode block B that is the target of the touch detection operation among the 20 drive electrode blocks B1 to B20. Thereby, in the display panel 7, the transition time of the drive signal Vcom can be shortened.

  FIG. 30 shows a characteristic example of the rise time tr and the fall time tf of the drive signal Vcom in the display panel 1R according to the comparative example 2 and the display panel 7 according to the present embodiment. As shown in FIG. 30, in the display panel 7, since the drive electrode block B that is not subject to the touch detection operation is in a floating state, the load on the drive signal generation unit 15 can be reduced, and the drive signal Vcom transitions Time (rise time tr, fall time tf) can be shortened.

  In the display panel 7, the switch control signal Vsel is set to a low level (FIG. 29C) during the touch detection period Pt, and all the switches SWR, SWG, SWB of the selection switch unit 14 are turned off. That is, the pixel signal line SGL is in a floating state in the touch detection period Pt. Thereby, compared with the case where the voltage is applied to the pixel signal line SGL (modified example 2-1 described later), the capacitance of the drive electrode COML and the capacitance of the touch detection electrode TDL can be reduced. It is possible to shorten the time ttotal required for.

  As described above, in the present embodiment, the drive electrode block that is not subject to the touch detection operation is set in the floating state, so that the possibility of affecting the display image quality can be reduced.

  In this embodiment, since only the drive electrode block that is the target of the touch detection operation is used as the load of the drive signal generation unit in the touch detection period, the load of the drive signal generation unit is reduced. Can be shortened.

  In this embodiment, since the pixel signal line is floated in the touch detection period, the time required for touch detection can be shortened.

  Other effects are the same as in the case of the first embodiment.

[Modification 2-1]
In the above-described embodiment, the selection switch unit 14 is provided. However, the present invention is not limited to this, and the source driver may directly generate the pixel signal Vpix instead. Details of this modification will be described below.

  FIG. 31 illustrates a configuration example of the display panel 7B according to the present modification. 32A and 32B show examples of timing waveforms of the display panel 7B. FIG. 32A shows the waveform of the scanning signal Vscan, FIG. 32B shows the waveform of the pixel signal Vpix, and FIG. 32C shows the Vcom selection signal VCOMSEL. (D) shows the waveform of the impedance control signal ZSEL, (E) shows the waveform of the drive signal Vcom, and (F) shows the waveform of the touch detection signal Vdet.

  The display panel 7B includes a source driver 13B as shown in FIG. The source driver 13B generates and outputs a pixel signal Vpix (VpixR, VpixG, VpixB) based on the video signal and the source driver control signal supplied from the control unit 11. That is, unlike the source driver 13 according to the above embodiment, the source driver 13B does not generate the pixel signal Vsig, but directly generates the pixel signal Vpix, and uses the pixel signal Vpix as a display device with a touch detection function. 10 liquid crystal display devices 20. At that time, as shown in FIG. 32, the source driver 13B always applies the pixel signal Vpix to the pixel signal line SGL without floating the pixel signal line SGL.

  Even in this case, similarly to the display panel 7 according to the above-described embodiment, only the drive electrode block that is the target of the touch detection operation becomes a load of the drive signal generation unit, so that the transition time of the drive signal can be shortened.

  In the display panel 7 according to the above-described embodiment, unlike the display panel 7B according to the present modification, the pixel signal line SGL is floated in the touch detection period Pt. Thereby, the capacitance of the touch detection electrode TDL can be reduced. Specifically, when the drive electrode COML is in a floating state, the capacitance of the touch detection electrode TDL is disposed between the touch detection electrode TDL and the drive electrode COML, the drive electrode COML, and the lower side thereof. It becomes a serial capacitance with the capacitance between the pixel signal lines SGL. That is, the capacitance of the touch detection electrode TDL can be reduced by connecting the capacitors in series.

  As described above, in the display panel 7, since the time constant of the touch detection electrode TDL is reduced, the transition time (rise time tr and fall time tf) of the touch detection signal Vdet can be reduced, and the entire display panel can be reduced. The time ttotal required for touch detection can be shortened.

  FIG. 33 shows the time ttotal required for touch detection in the display panels 7B and 7. The time ttx indicates the time attributed to the drive electrode COML among the time ttotal required for touch detection, and the time trx indicates the time attributed to the touch detection electrode TDL.

  As described above, in the display panel 7, the time constant of the touch detection electrode TDL can be reduced. Therefore, the time trx caused by the touch detection electrode TDL can be shortened, and the time required for touch detection in the entire display panel. ttotal can be shortened.

[Modification 2-2]
Modifications 1-1 and 1-2 of the first embodiment may be applied to the display panel 7 according to the above-described embodiment.

<4. Application example>
Next, application examples of the display panel described in the above embodiment and modifications will be described.

  FIG. 34 illustrates an appearance of a television device to which the display panel of the above-described embodiment or the like is applied. The television apparatus has, for example, a video display screen unit 510 including a front panel 511 and a filter glass 512, and the video display screen unit 510 is configured by the display panel according to the above-described embodiment and the like. .

  The display panel of the above embodiment is an electronic device in various fields such as a digital camera, a notebook personal computer, a portable terminal device such as a mobile phone, a portable game machine, or a video camera in addition to such a television device. It is possible to apply to. In other words, the display panel of the above embodiment and the like can be applied to electronic devices in all fields that display video.

  The present technology has been described above with some embodiments and modifications, and application examples to electronic devices. However, the present technology is not limited to these embodiments and the like, and various modifications are possible. is there.

  For example, in the above embodiment and the like, as shown in FIG. 6, the drive electrode COML is formed on the TFT substrate 21, and the pixel electrode 22 is formed thereon via the insulating film 23. However, the present invention is not limited to this. Instead, for example, the pixel electrode 22 may be formed on the TFT substrate 21, and the drive electrode COML may be formed thereon via the insulating film 23.

  Further, for example, in the above-described embodiment, a liquid crystal display device using a liquid crystal in a horizontal electric field mode such as FFS and IPS and a touch detection device are integrated, but instead of this, TN (twisted nematic), VA A liquid crystal display device using a liquid crystal of various modes such as (vertical alignment) and ECB (electric field control birefringence) may be integrated with a touch detection device. When such a liquid crystal is used, a display device with a touch detection function can be configured as shown in FIG. FIG. 35 illustrates an example of a cross-sectional structure of a main part of a display device with a touch detection function 10D according to this modification, and illustrates a state in which the liquid crystal layer 6B is sandwiched between the pixel substrate 2B and the counter substrate 3B. ing. The names and functions of the other parts are the same as those in FIG. In this example, unlike the case of FIG. 6, the drive electrode COML that is used for both display and touch detection is formed on the counter substrate 3B.

  Further, for example, in each of the above embodiments, a so-called in-cell type in which a liquid crystal display device and a capacitive touch detection device are integrated is not limited to this, and instead of this, for example, A so-called on-cell type in which a capacitive touch detection device is formed on the surface of the liquid crystal display device may be used. In the on-cell type, for example, when display drive noise propagates from a liquid crystal display device to a touch detection device, the noise can be reduced by driving as in the above embodiment. A decrease in detection accuracy can be suppressed.

  Further, for example, in each of the above embodiments, the display element is a liquid crystal element. However, the display element is not limited to this, and instead, for example, an EL (Electro Luminescence) element may be used.

  In addition, this technique can be set as the following structures.

(1) a plurality of display elements;
A plurality of drive electrodes;
One or more touch detection electrodes that form capacitance between each drive electrode;
A signal generator for generating a plurality of DC signals having different voltages from each other;
And a drive unit that selectively applies the plurality of DC signals to each drive electrode.

(2) The plurality of DC signals are a first DC signal and a second DC signal,
The driving unit applies the first DC signal to the plurality of driving electrodes in a writing period in which a pixel signal is written to the display element, and includes a touch detection period different from the writing period. The display panel according to (1), wherein, in at least a part of the period, the second DC signal is applied to one or a plurality of driving target electrodes that are targets of touch detection among the plurality of driving electrodes. .

(3) The display panel according to (2), wherein the driving unit is disposed in the vicinity of the plurality of driving electrodes.

(4) The drive unit described above in (2) or (3), in which the drive electrode other than the drive target electrode among the plurality of drive electrodes is in an electrically floating state in the touch detection period. Display panel.

(5) In the touch detection period, the drive unit applies the first DC signal to drive electrodes other than the drive target electrode among the plurality of drive electrodes. ) Display panel.

(6) A pixel signal generation unit that generates the pixel signal, and a plurality of signal lines that transmit the pixel signal,
The pixel signal generation unit applies the pixel signal to the plurality of signal lines in the writing period, and sets the plurality of signal lines in a floating state in the touch detection period. The display panel according to any one of 5).

(7) A pixel signal generation unit that generates the pixel signal, and a plurality of signal lines that transmit the pixel signal,
The display panel according to any one of (2) to (5), wherein the pixel signal generation unit applies the pixel signal to the plurality of signal lines in the writing period and the touch detection period.

(8) The writing period of 1 exists in one horizontal period,
The display panel according to any one of (2) to (7), wherein the touch detection period is provided at a ratio of one to a plurality of writing periods.

(9) The writing period of 1 exists in one horizontal period,
The display panel according to any one of (2) to (7), wherein the touch detection period is provided at a rate of one writing period.

(10) The display panel according to any one of (1) to (9), wherein the driving unit drives the plurality of driving electrodes in units of electrode blocks including a predetermined number of driving electrodes.

(11) The display element
A liquid crystal layer;
Any one of (1) to (10), comprising: a pixel electrode formed between the liquid crystal layer and the drive electrode, or arranged to face the liquid crystal layer with the drive electrode interposed therebetween A display panel according to Crab.

(12) The display element is:
A liquid crystal layer;
The display panel according to any one of (1) to (10), including: a pixel electrode disposed so as to face the drive electrode with the liquid crystal layer interposed therebetween.

(13) a signal generator that generates a plurality of DC signals having different voltages from each other;
A drive circuit comprising: a drive unit that selectively applies the plurality of DC signals to each of a plurality of drive electrodes that form capacitance between one or a plurality of touch detection electrodes.

(14) Generate a plurality of DC signals having different voltages from each other, and selectively select the plurality of DC signals for each of the plurality of drive electrodes forming a capacitance with one or a plurality of touch detection electrodes. Applied to the driving method.

(15) a display panel;
A control unit that performs operation control using the display panel,
The display panel is
A plurality of display elements;
A plurality of drive electrodes;
One or more touch detection electrodes that form capacitance between each drive electrode;
A signal generator for generating a plurality of DC signals having different voltages from each other;
And a drive unit that selectively applies the plurality of DC signals to each drive electrode.

  DESCRIPTION OF SYMBOLS 1, 7, 7B ... Display panel, 2, 2B ... Pixel substrate, 3, 3B ... Opposite substrate, 6, 6B ... Liquid crystal layer, 10 ... Display device with a touch detection function, 11 ... Control part, 12, 12A, 12B ... Gate driver, 13 ... source driver, 14 ... selection switch, 15 ... drive signal generator, 16, 16A, 16B, 16C, 16D, 18 ... drive electrode driver, 17 ... switch group, 20 ... liquid crystal display device, 21 ... TFT substrate, 22 ... pixel electrode, 23 ... insulating layer, 30 ... touch detection device, 31 ... glass substrate, 32 ... color filter, 35 ... polarizing plate, 40 ... touch detection unit, 42 ... LPF unit, 43 ... A / D Conversion unit 44 ... Signal processing unit 45 ... Coordinate extraction unit 46 ... Detection timing control unit 51,61,71 ... Scan control unit 52 ... Touch detection scan unit 53,530, DESCRIPTION OF SYMBOLS 3 ... Drive part, 54, 68, 69, 73, 74 ... AND circuit, 55, 67 ... Inverter, 56, 57 ... Buffer, 62 ... Decoder, 63 ... 4-bit decoder, 72, 78, 79 ... OR circuit, A, A1 to A20: Partial display area, B, B1 to B20 ... Drive electrode block, COML ... Drive electrode, DI ... Input code, GCL ... Scanning signal line, LC ... Liquid crystal element, LDC, LH ... Wiring, Out ... Output Signal, Pd ... Display period, Pix ... Pixel, Pt ... Touch detection period, Pw ... Write period, Spix ... Sub-pixel, Scan ... Display scan, Scan ... Touch detection scan, SGL ... Pixel signal line, St ... Scan signal, SWR, SRG, SWB, SW1, SW2 ... switch, T ... flexible printed circuit board, TDL ... touch detection electrode, Tr ... TFT element, tr ... rise time, tf ... fall Ts ... sampling timing, ttotal ... time, Vcom ... drive signal, VcomDC, VcomH ... DC drive signal, VCOMSEL ... Vcom selection signal, Vdet ... touch detection signal, VH ... voltage, Vscan ... scan signal, Vsel, VselR, VselG , VselB: switch control signal, Vsig, Vpix, VpixR, VpixG, VpixB: pixel signal, ZSEL: impedance control signal.

Claims (16)

A display panel in which a plurality of display elements are formed ;
A plurality of drive electrodes;
One or more touch detection electrodes that form capacitance between each drive electrode;
A plurality of DC signal supply lines formed along at least one side of the frame portion of the display panel;
A signal generator that generates a plurality of DC signals having different voltages and outputs the signals to the plurality of DC signal supply wirings ;
A display that is formed on the at least one side of the frame portion of the display panel and that selectively applies the plurality of DC signals supplied from the plurality of DC signal supply wirings to each drive electrode. Equipment . Each of the plurality of DC signal supply wirings is formed along two opposite sides of the frame portion of the display panel,
The drive unit includes a first drive unit formed along one of two opposing sides of the frame portion of the display panel, and the other of the two opposing sides of the frame portion of the display panel. A second drive unit formed along the side.
The display device according to claim 1. The plurality of DC signals are a first DC signal and a second DC signal,
The driving unit applies the first DC signal to the plurality of driving electrodes in a writing period in which a pixel signal is written to the display element, and includes a touch detection period different from the writing period. 3. The display according to claim 1, wherein the second DC signal is applied to one or a plurality of drive target electrodes that are targets of touch detection among the plurality of drive electrodes in at least a part of the period. Equipment . The display device according to claim 3 , wherein the drive unit is disposed in the vicinity of the plurality of drive electrodes. The display device according to claim 3 , wherein the drive unit electrically drives drive electrodes other than the drive target electrode among the plurality of drive electrodes in the touch detection period. The display device according to claim 3 , wherein the drive unit applies the first DC signal to drive electrodes other than the drive target electrode among the plurality of drive electrodes in the touch detection period. A pixel signal generation unit that generates the pixel signal; and a plurality of signal lines that transmit the pixel signal;
The pixel signal generation unit, in the writing period, the pixel signal is applied to the plurality of signal lines, in the touch detection period, according to claim 3, said plurality of signal lines to a floating state Display device . A pixel signal generation unit that generates the pixel signal; and a plurality of signal lines that transmit the pixel signal;
The display device according to claim 3 , wherein the pixel signal generation unit applies the pixel signal to the plurality of signal lines in the writing period and the touch detection period. One writing period exists in one horizontal period;
The display device according to claim 3 , wherein the touch detection period is provided at a ratio of one to a plurality of writing periods. One writing period exists in one horizontal period;
The display device according to claim 3 , wherein the touch detection period is provided at a rate of one for one writing period. The drive unit, a display device according to the plurality of drive electrodes, to claim 1 or 2 for driving a unit of electrode block of the drive electrodes of the predetermined number. The display element is
A liquid crystal layer;
Wherein formed between the liquid crystal layer and the drive electrode, or the display device according to claim 1 or 2 configured to include a pixel electrodes arranged to face the liquid crystal layer across the driving electrodes . The display element is
A liquid crystal layer;
The display device according to claim 1 or 2 configured to include a pixel electrodes arranged so as to face the drive electrodes sandwiching the liquid crystal layer. A plurality of DC signal supply wirings formed along at least one side of the frame portion of the display panel;
A signal generator that generates a plurality of DC signals having different voltages and outputs the signals to the plurality of DC signal supply wirings ;
Supplied from the plurality of DC signal supply lines to each of a plurality of drive electrodes formed on the at least one side of the frame portion of the display panel and forming a capacitance with one or a plurality of touch detection electrodes. drive circuit and a drive unit for selectively applying said plurality of DC signals. A plurality of DC signals having different voltages are generated and output to a plurality of DC signal supply wirings formed along at least one side of the frame portion of the display panel, and electrostatic capacitance is provided between one or a plurality of touch detection electrodes. A driving method in which the plurality of DC signals supplied from the plurality of DC signal supply wirings are selectively applied to each of a plurality of driving electrodes that form the electrode. A display device ;
A control unit that performs operation control using the display device ,
The display device
A display panel in which a plurality of display elements are formed ;
A plurality of drive electrodes;
One or more touch detection electrodes that form capacitance between each drive electrode;
A plurality of DC signal supply lines formed along at least one side of the frame portion of the display panel;
A signal generator that generates a plurality of DC signals having different voltages and outputs the signals to the plurality of DC signal supply wirings ;
A drive unit that is formed on the at least one side of the frame portion of the display panel and selectively applies the plurality of DC signals supplied from the plurality of DC signal supply wirings to each drive electrode. .

Images