JP2015232601A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which: since a touch panel of an in-cell system includes an electrode that serves as both a common electrode for display and a scanning electrode for a touch panel, the electrode needs to be used in a time-division manner.SOLUTION: A display device includes an opposing electrode that serves as both a common electrode for display and a scanning electrode for touch detection, a first scanning circuit that scans gate lines, and a second scanning circuit that scans the opposing electrode. The display device has a second mode having, within one frame period, a writing period to continuously scan one screen and a touch detection period between the writing period and a writing period in the subsequent frame, and a first mode having writing periods and touch detection periods appearing alternately a plurality of times.

Description

  The present disclosure relates to a display device, and can be applied to a display device having an in-cell touch panel, for example.

  Japanese Unexamined Patent Publication No. 2012-230657 (Patent Document 1) and US Patent Application Publication No. 2012/262387 (Patent Document 2) corresponding thereto disclose the following. In the embodiment, in each horizontal period (1H), a touch detection period (Pt) for performing the touch detection operation and a writing period (Pw) for writing the pixel signal (Vpix) in the display operation are provided. It is done. In the modification, 20 touch detection periods (Pt) and 20 display periods (Pd) are alternately arranged in one frame period (1F).

JP 2012-230657 A US Patent Application Publication No. 2012/262387

In the in-cell type touch panel of Patent Document 1 or Patent Document 2, since the common electrode for display and the scan electrode for the touch panel are also used, the electrodes that are also used are used in a time-sharing manner. That is, pixel writing and touch detection cannot be performed simultaneously. Therefore, it is necessary to adjust the writing period (gate line scanning period) and the touch detection period (common line scanning period).
Other problems and novel features will become apparent from the description of the present disclosure and the accompanying drawings.

The outline of a representative one of the present disclosure will be briefly described as follows.
That is, the display device includes a common electrode for display and a scan electrode for touch detection, a counter electrode that is shared, a first scan circuit that scans the gate line, and a second scan that scans the counter electrode. A circuit. The display device includes a second mode having a writing period for continuously scanning one screen within one frame period, and a touch detection period between the writing period and a writing period for the next frame, and within one frame period. And a first mode in which a writing period and a touch detection period appear alternately a plurality of times. The first scanning circuit has a first shift register unit. The second scanning circuit includes a second shift register unit and a switch unit. The first scanning circuit is disposed between the second shift register unit and the switch unit in plan view. Each of the first scanning circuit and the second scanning circuit is composed of a single channel thin film transistor.

It is a figure for demonstrating the writing period and touch detection period which concern on the system of a comparative example. It is a figure for demonstrating the writing period and touch detection period which concern on the system of a comparative example. It is a figure for demonstrating the writing period and touch detection period which concern on a 1st system. It is a figure for demonstrating the writing period and touch detection period which concern on a 1st system. It is a figure for demonstrating the writing period and touch detection period which concern on a 2nd system. It is sectional drawing of the display apparatus which concerns on an Example. It is a top view of the opposing board | substrate of the display apparatus which concerns on an Example. It is a top view of the array substrate of the display apparatus which concerns on an Example. It is the figure which represented typically the example of mounting of the display apparatus which concerns on an Example. It is a block diagram of the part formed on the array substrate of the display apparatus which concerns on an Example. It is a block diagram of a touch detection part. It is a block diagram of the touch detection part of the display apparatus which concerns on an Example. It is a block of the two-line simultaneous scanning circuit of the display device according to the example. It is a timing chart at the time of line sequential drive. It is a timing chart at the time of 2-line simultaneous drive. It is a circuit diagram of the shift register part of the gate scan circuit of the display apparatus which concerns on an Example. It is a timing chart of the shift register part of the gate scan circuit in a 2nd system. It is a circuit diagram of the shift register part of the gate scan circuit which concerns on a modification. It is a circuit diagram of the division part of the gate scan circuit of the display apparatus which concerns on an Example. It is a block diagram of the common scan circuit of the display apparatus which concerns on an Example. It is a circuit diagram of the shift register part of the common scan circuit of the display apparatus which concerns on an Example. It is a timing chart of the shift register part in the 2nd system. It is a circuit diagram of the switch part of the common scan circuit of the display apparatus which concerns on an Example. It is a timing chart of the switch part of the common scan circuit of the display apparatus which concerns on an Example.

  Hereinafter, examples will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.

  As described above, since the in-cell type touch panel serves as the common electrode for display and the scan electrode for the touch panel, pixel writing and touch detection cannot be performed at the same time. The shared electrode must be used in a time-sharing manner. That is, it is necessary to adjust the writing period (gate line scanning period) and the touch detection period (common line scanning period). It is also necessary to avoid wide frequency band noise. Hereinafter, a method for adjusting the writing period and the touch detection period will be described.

<Method of comparative example>
First, a technique (hereinafter referred to as a comparative example) studied prior to the present disclosure will be described with reference to FIGS. 1 and 2.
1 and 2 are diagrams for explaining a writing period and a touch detection period according to the method of the comparative example.
In the gate scan (LCD Gate scan) operation A, pixels from the first display line to the 1280 display line are written in the pixel writing period (T4) of one frame. In the common scan (VCOM scan) operation B, for example, touch panel detection is performed on the common electrode of each block divided into 20 blocks. In FIG. 1, T3 is a blanking period, Vsync is a vertical synchronization signal, and Hsync is a horizontal synchronization signal.
As shown in FIG. 1, a common scan operation (touch detection operation) B at the time of touch detection is a gate scan operation (display operation) in which pixel writing is performed by causing a common electrode of an arbitrary display line to function as a scan electrode for a touch panel. It is performed at a location different from A. Since the common electrode is also operated as a scanning electrode for the touch panel, the display operation A using the same common electrode and the touch position detection operation B are completely time-divisionally controlled synchronously.
As shown in FIG. 2, in the method of the comparative example, the display operation (pixel writing) A and the touch detection operation (drive of the touch panel scanning voltage (V _TX )) B are executed in one horizontal period (1H). Although the gate scan operation A and the common scan operation B are performed on different display lines, there is a parasitic capacitance between the video line and the common electrode and between the gate line and the common electrode. The detection sensitivity at the time of touch detection decreases due to fluctuations in the video voltage (V _DL ) or noise generated at the rise or fall of the scanning voltage (V _GL ) on the gate line. Note that since the method according to the comparative example employs column inversion as the alternating drive method, the common voltage (Vcom) supplied to the common electrode is a constant potential.
Therefore, in the method according to the comparative example, the touch detection operation B is performed during a period in which there is no fluctuation in the video voltage (V _DL ) or rise or fall of the scanning voltage (V _GL ) (first period ( TA) and second period (TB)).
Further, in the method according to the comparative example, as a countermeasure against external noise such as noise generated from a charger, so-called AC charger noise, the touch panel scanning voltage (V _TX ) is applied to the same scanning electrode a plurality of times over a plurality of horizontal scanning periods ( For example, the timing for supplying the touch panel scanning voltage (V _TX ) to the scanning electrode is stored in the register with reference to the touch panel scanning start waiting period (Txs) every horizontal scanning period. The unit delay time is delayed. The touch panel scanning start waiting period (Txs) based on the falling edge of the horizontal synchronization signal (Hsync) is set with a margin in order to avoid fluctuations in the video voltage (V _DL ) on the video line.
However, in the method according to the comparative example, the touch panel is between the end of the first period (TA) and the start of the second period (TB) and between the end of the second period (TB) and the start of the first period (TA). The scanning voltage (V _TX ) cannot be supplied. Thus, at the beginning and end of the first period (TA), and with respect to the end with the second start period (TB), it is necessary to supply a touch panel scanning voltage _{(V TX)} with a margin, the touch panel scanning voltage _{(V TX} ) Is difficult to control.

<First method>
The writing period and the touch detection period according to the first method will be described with reference to FIGS.
3 and 4 are diagrams for explaining the writing period and the touch detection period according to the first method.
In the first method, one vertical period (1 V period) or one frame display period includes a period for driving a video signal and a scanning signal (Sig) (writing period (PIX)) and a touch panel scanning voltage (V _TX ). It is divided into driving periods (touch detection period (TP)) and driven alternately. This is called divided V blank drive. The display period of one frame has N writing periods (PIX) and N touch detection periods (TP). In one writing period (PIX), for example, 1280 / N lines are scanned, and in one touch detection period (TP), 20 / M scanning electrodes (common electrodes) are scanned. For example, when N = 20 and M = 20, 64 lines are scanned in one writing period (PIX), and one scanning electrode is scanned in one touch detection period (TP). A touch panel scanning voltage (V _TX ) of 20 to 40 times is applied to one scanning electrode. Here, M is a natural number and may be larger, the same or smaller than N. To increase the number of touch detections in one vertical period (for example, 4 times), if N = 20 and M = 5, four touch detections in one vertical period can be performed on all the common electrodes. , Detection accuracy goes up. If it is desired to reduce the number of touch detections in one vertical period (for example, 1/2 in one vertical period, that is, once in 2 vertical periods), if N = 20 and M = 40, then once in 2 vertical periods The touch detection is performed on all the common electrodes, and the power consumption in the touch detection is reduced. The values of N and M are determined by setting values from a host controller in a storage circuit such as a register of a driver IC described later.
Since the display common electrode functions as a scan electrode for touch detection, as shown in FIGS. 3 and 4, the common scan operation at the time of touch panel detection is a period in which the gate scan operation for pixel writing is not performed. To do. That is, since the writing period (PIX) and the touch detection period (TP) are separated, the touch detection operation can be performed by changing the voltage (V _DL ) on the video signal line or the voltage (V _GL ) on the scanning signal line. It is easy to execute during a period when there is no rise or fall. Further, except for the beginning and end of the touch detection period (TP), it is possible to supply the touch panel scanning voltage (V _TX), as external noise countermeasure such as an AC charger noise, scan electrode touch panel scanning voltage (V _TX) It is easier to shift the timing of supplying the signal than the method of the comparative example.

<Second method>
A writing period and a touch detection period according to the second method will be described with reference to FIG.
FIG. 5 is a diagram for explaining a writing period and a touch detection period according to the second method. 5A shows a writing period and a touch detection period according to the first method, and FIG. 5B shows a writing period and a touch detection period according to the second method.
In the second method, one vertical period or one frame display period (1 flame period) drives a video signal or a scanning signal (writing period (PSP)) and a touch panel scanning voltage (V _TX ). It is divided into a period (touch detection period (TSP)). In other words, in one frame period, the period during which the video signal and the scanning signal are driven (PSP) is set only once, and the period during which the touch panel scanning voltage (V _TX ) is driven is set only once (TSP). Yes. In other words, the writing period (PSP) has consecutive N writing periods (PIX), and the touch detection period (TSP) has continuous M touch detecting periods (TP). . Similar to the first method, for example, 1280 / N lines are scanned in one writing period (PIX), and 20 / M scanning electrodes (common electrodes) are scanned in one touch detection period (TP). For example, when N = 20 and M = 20, 64 lines are scanned in one writing period (PIX), and one scanning electrode is scanned in one touch detection period (TP). Accordingly, 1280 lines are scanned in the writing period (PSP), and 20 scan electrodes are scanned in the touch detection period (TSP). A touch panel scanning voltage (V _TX ) of 20 to 40 times is applied to one scanning electrode. Here, M is a natural number and may be larger, the same or smaller than N. To increase the number of touch detections in one vertical period (for example, 4 times), if N = 20 and M = 5, four touch detections in one vertical period can be performed on all the common electrodes. , Detection accuracy goes up. When it is desired to reduce the number of touch detections in one vertical period (for example, 1/2 times and once in 2 vertical periods), if N = 20 and M = 40, all touch detections are performed once in 2 vertical periods. Since this is performed by the common electrode, power consumption in touch detection is reduced. The values of N and M are determined by setting values from a host controller in a storage circuit such as a register of a driver IC described later.
In the second method, since the writing period (PSP) and the touch detection period (TSP) are completely separated, the touch position detection operation can be performed by changing the voltage (V _DL ) on the video signal line or on the scanning signal line. It is easy to execute in the period when the voltage (V _GL ) rises or does not fall. Further, since the continuous touch detection period (TSP) is longer than the touch detection period (TP) of the first method, a touch panel scanning voltage (V _TX ) is supplied to the scanning electrodes as a countermeasure against external noise such as AC charger noise. It is easier to shift the timing to perform than the first method.

<Embodiment>
The display device according to the embodiment can be operated by both the first method (first mode) and the second method (second mode). As a countermeasure against external noise such as AC charger noise, it is possible to easily shift the timing of supplying the touch panel scanning voltage (V _TX ) to the scanning electrodes. The designation of the first method and the second method is determined by setting a value from the host controller in a storage circuit such as a register of the driver IC.

The time between the writing period of the second method and the next writing period and the time between the touch detection period and the next touch detection period are longer than those of the first method. This long time may adversely affect a dynamic circuit using a single channel thin film transistor. A dynamic circuit performs circuit operation by charging and discharging a signal node using a periodically generated clock signal. However, if this clock signal is not generated for a long time, a leak occurs in the signal node. Leakage can be prevented by adding a large capacitance to the signal node, but the circuit scale becomes large.
Therefore, in a display device according to another embodiment, in a circuit including a single channel transistor, a clock signal or a touch period that is also output between the writing period and the next writing period (touch detection period) or the next touch is displayed. The signal node is charged using the output clock signal during the period (writing period) to prevent leakage. Here, the single channel transistor is, for example, an n-channel thin film transistor. Since a large storage capacitor is not added to the signal node, the storage capacitor area can be reduced, the circuit width can be reduced, and the display panel can be narrowed. In addition, since a circuit can be formed using a single channel transistor, it is not necessary to use a complementary transistor (CMOS), and the manufacturing process can be reduced and the cost can be reduced.

  In the following embodiments, a so-called lateral electric field type liquid crystal display device in which a common electrode is formed on an array substrate will be described, but the present invention is not limited to this. The present invention can also be applied to a so-called vertical electric field type liquid crystal display device in which a common electrode is formed on a counter substrate. Further, the scanning electrode for touch detection is not limited to the common electrode for the liquid crystal display device, and the scanning electrode for the touch detection may be a display electrode.

The display device according to the embodiment is an in-cell display device in which a touch panel is built in a display panel. The structure of the display device according to the example will be described with reference to FIGS.
FIG. 6 is a cross-sectional view for explaining the display device according to the example. FIG. 7 is a plan view for explaining the counter substrate of the display device according to the example. FIG. 8 is a plan view for explaining the array substrate of the display device according to the example.
As illustrated in FIG. 6, the display device 100 according to the embodiment includes a display panel 1, a driver IC 5, a flexible wiring board 6, a flexible wiring board 7, and a backlight 2. The display panel 1 includes a sealing material (not shown) provided in a frame shape in the vicinity of the peripheral edge between the array substrate 10 and the counter substrate 20 by overlapping the array substrate 10 and the counter substrate 20 with a predetermined gap therebetween. Thus, the array substrate 10 and the counter substrate 20 are bonded together, and the liquid crystal composition 30 is sealed and sealed inside the sealing material, and the polarizing plates 40 and 50 are disposed outside the array substrate 10 and the counter substrate 20. It is configured by pasting.
As shown in FIG. 7, the back-side transparent conductive film on the counter substrate 20 is divided into strip-like (striped) patterns, and the touch panel detection electrodes (Rx1, Rx2,..., Rxj-1, Rxj) 21. The detection electrode 21 extends in the Y direction. The detection electrode 21 of the touch panel is connected to the connection unit 8. As shown in FIG. 8, the common electrode (counter electrode) 11 formed inside the array substrate 10 is divided into strip-shaped patterns, that is, divided into a plurality of blocks, which are also used as scanning electrodes for the touch panel. By these, the touch panel board | substrate used with a normal touch panel is reduced.
In the display device 100, touch panel driving and detection circuits are provided inside the driver IC 5. The driver IC 5 is formed on one semiconductor substrate by a CMOS process, and is mounted on the array substrate 2 by COG (Chip on Glass) in the form of a semiconductor chip.

As shown in FIG. 8, n (for example, 20) common electrodes (COM 1, COM 2,... COMM−1, COMn) 11 are provided on the array substrate 10. The common electrode 11 is connected to the common scan circuit (Tx) 13 at both ends. In the display device 100, the strip-shaped common electrode 11 also serves as a scanning electrode. Accordingly, the common scan circuit (Tx) 13 includes a common voltage (Vcom, a direct current drive signal described later) used for image display, and a touch panel scan voltage (V _TX , an alternating current drive signal described later) used for detecting the touch position. Is supplied to the common electrode 11. In addition to the common scan circuit (Tx) 13, the array substrate 10 includes a gate scan circuit (GIP) 12, a scan signal line (a gate line described later), a video signal line (a drain line described later), and a flexible wiring substrate 6. Various circuits such as the input terminal 14 for the driver IC 5, which is a connection terminal, wiring, terminals, and the like are formed. In FIG. 8, a selector circuit for selecting an RGB video signal is omitted in order to avoid complication of the drawing.

The array substrate 10 is provided with a pixel portion 15, and the common electrode 11 and a pixel electrode (not shown) are used for image display as part of the pixel. One common electrode 11 is commonly used for a plurality of pixels (for example, pixels of 64 lines). The detection electrode 21 provided on the counter substrate 20 and the common electrode 11 provided on the array substrate 10 form a capacitance. When a touch panel scanning voltage (V _TX ) is applied to the common electrode 11, The voltage changes. At this time, when a conductor such as a finger approaches or comes in contact, the capacitance changes, and the voltage generated in the detection electrode 21 changes compared to the case where there is no proximity / contact. This change is taken out as a detection signal to the driver IC 5 through the connection portion 8, the flexible wiring board 7, the connector 9, and the flexible wiring board 6, as shown in FIG. Thus, by detecting a change in capacitance generated between the common electrode 11 and the detection electrode 21 formed on the display panel, the display panel can be provided with a touch panel function.
The display device 100 can operate in any of the first method and the second method described above regarding the writing period and the touch detection period. It is determined by setting a value in the register of the driver IC 5 from the host controller. The register or the like includes a storage circuit such as a register, a volatile memory such as a RAM, an electrically rewritable nonvolatile memory such as an EEPROM or a flash memory.

A detailed configuration of the display device according to the embodiment will be described with reference to FIGS. 9 to 11.
FIG. 9 is a plan view for explaining the array substrate of the display device according to the example. FIG. 9 shows FIG. 8 in more detail. 10 and 11 are block diagrams of the display device according to the embodiment. FIG. 10 is a configuration diagram of a portion formed on the array substrate. FIG. 11 is a configuration diagram of the touch detection portion.
The driver IC 5 sends a video signal to pixels (a thin film transistor TRmk and a pixel electrode PTmk, which will be described later) arranged in a matrix in the pixel unit 15 via a wiring (a drain line DLm which will be described later) on the array substrate 10. The gate scan circuit (GIP) 12 is formed in the vicinity of the pixel portion (display area) 15 on the array substrate 10 using a TFT (Thin Film Transistor) element. In this example, the gate scan circuit 12 is disposed on the right side and the left side of the array substrate 10 in FIG. 7, and receives supply of a power supply voltage, a control signal, and the like from the driver IC 5 via wiring. The pixels arranged in a matrix in the pixel unit 15 can be driven from both sides. In addition, it is not limited to a both-side drive, You may make it drive every gate line alternately from right and left (one side drive).
The common scan circuit 13 is divided into a shift register unit (Tx (S / R)) 13SR and a switch unit (Tx (SW)) 13SW, and is arranged with the gate scan circuit 12 interposed therebetween. The common scan circuit 13 (13SR, 13SW) is formed on the array substrate 10 using TFT elements. In this example, the common scan circuit 13 is arranged on the right side and the left side of the array substrate 10 in FIG. 9, and supplies an AC drive signal (VCOMAC), a DC drive signal (VCOMDC), and the like to be described later from the driver IC 5 via wiring. Receive. The common scan circuit 13 can drive each of a plurality of common electrodes (COM1, COM2,... COMM-1, COMn) 11 arranged in parallel from both sides. In addition, it is not limited to a both-side drive, You may make it drive every one common electrode from right and left alternately (one side drive). As will be described later, when the common scan circuit 13 is configured by a single channel transistor, it is necessary to form a storage capacitor or the like. For this reason, due to layout constraints (with the relationship that a storage capacitor with a large layout area is arranged near the edge of the display panel where there is room and a switch circuit for driving a common electrode with a large load is arranged close to the pixel portion 15) The shift register unit 13SR, the gate scan circuit 12, and the switch unit (Tx (SW)) 13SW are preferably arranged in this order from the end of the display panel.

As shown in FIG. 10, the array substrate 10 is provided with n sets of k gate lines GL1 to GLk extending in the X direction, n common lines CL1 to CLn, and m drain lines DL1 extending in the Y direction. ~ DLm are provided.
A region surrounded by adjacent gate lines and drain lines including the gate line GLk and the drain line DLm is a pixel region Pmk, and a thin film transistor TRmk and a pixel electrode PTmk are provided in the pixel region Pmk. The drain electrode of the thin film transistor TRmk is connected to the drain line DLm, the gate electrode of the thin film transistor TRmk is connected to the gate line GLk, and the source electrode of the thin film transistor TRmk is connected to the pixel electrode PTmk. A common electrode (COM1) 11 is provided to face the pixel electrode PTmk, and the common electrode (COM1) 11 is connected to the common electrode signal line CL1. The pixel region is not limited to the pixel region Pmk but is in a region surrounded by adjacent gate lines and drain lines. Therefore, there are m × n × k pixel electrodes. Each of the common electrodes (COM1, COM2,... COMn-1, COMn) 11 is commonly used for m × k pixels.
Common scan circuits 13 are provided at the left and right edges of the array substrate 10, and common electrode signals (C 1 to Cn) are applied to the common lines CL 1 to CLn extending in the X direction parallel to each other by the common scan circuit 13 SW. It is driven from. Gate scan circuits 12 are also provided on the left and right edges of the array substrate 10, and gate signals (G 1,...) Are supplied to the gate lines GL 1 to GLnk extending in the X direction in parallel with each other by these gate scan circuits 12. Gk,... Gnk) are driven from the left and right ends. Further, a driver IC 5 is provided on the lower frame portion of the array substrate 10, and the drain lines DL <b> 1 to DLm extending in the Y direction parallel to each other are driven from the lower end by the driver IC 5.

  As shown in FIG. 11, j detection electrodes (Rx1 to Rxj) 21 extending in the Y direction are provided on the counter substrate 20. Signals (TD1 to TDj) from the detection electrodes (Rx1 to Rxj) 21 are input to the driver IC 5 through the detection electrode signal lines TDL1 to TDLj. The driver IC 5 includes a detection circuit (not shown) that detects a touch, and the detection circuit includes an integration circuit, a sample hold circuit, an A / D conversion circuit, a memory, a CPU, and the like. Note that the detection circuit may be configured as an IC (integrated circuit) different from the driver IC 5.

  Hereinafter, the gate scan circuit (first scan circuit) and the common scan circuit (second scan circuit) will be described. Note that the transistors used for the gate scan circuit and the common scan circuit are both n-channel thin film transistors (single channel thin film transistors), and are formed of, for example, low-temperature polysilicon. It is needless to say that the transistors constituting the gate scan circuit and the common scan circuit are not limited to n-channel thin film transistors, and can be composed of p-channel thin film transistors (single channel thin film transistors).

<Gate scan circuit>
A gate scan circuit of the display device according to the example will be described with reference to FIGS.
In the following embodiments, the gate scan circuit will be described as having both two-line simultaneous drive and line-sequential drive functions, but the present invention is not limited to this. There may be only a line-sequential drive function without a 2-line simultaneous drive function. A power supply voltage, a clock signal, a control signal, and the like used in the gate scan circuit are generated by a voltage generation circuit, a control circuit, and the like of the driver IC 5. The power supply voltages used for the gate scan circuit are an intermediate voltage (DDVDH) and a low voltage (VGPL). The intermediate voltage (DDVDH) makes the transistor conductive, but is a voltage lower than a high voltage (high voltage (VGH)) of a gate signal described later in the common scan circuit. The low voltage (VGPL) is a low voltage of the gate signal, and cuts off the transistor with a voltage lower than the intermediate voltage (DDVDH).

(overall structure)
FIG. 12 is a block diagram of the gate scan circuit of the display device according to the embodiment. FIG. 13 is a timing chart during line sequential driving. FIG. 14 is a timing chart when two lines are simultaneously driven.
The gate scanning circuit 12 includes a shift register unit (first shift register unit) 12S having a transfer function and a dividing unit 12D having a function of outputting to each gate line. The shift register unit 12S has a shift register circuit SRn and a shift register circuit SRn + 1 connected in cascade, and sequentially operates in accordance with a first shift clock signal (SCK1) and a second shift clock signal (SCK2) having different phases. Dividing unit 12D distributes the output of shift register circuit SRn to two dividing circuits DVn-1 and dividing circuit DVn. The divider circuit DVn-1 outputs a gate signal (Gn-1) to the gate line GLn-1 by the first gate clock signal (GCK1), and the divider circuit DVn gates to the gate line GLn by the second gate clock signal (GCK2). A signal (Gn) is output. Similarly, the dividing unit 12D distributes the output of the shift register circuit SRn + 1 to the two dividing circuits DVn + 1 and the dividing circuit DVn + 2. The dividing circuit DVn + 1 outputs a gate signal (Gn + 1) to the gate line GLn + 1 by the first gate clock signal (GCK1), and the dividing circuit DVn + 2 outputs the gate signal (Gn + 2) to the gate line GLn + 2 by the second gate clock signal (GCK2). To do. In FIG. 12, some of the signal lines and the like described in FIG. 15 are omitted.
As shown in FIG. 13, during line sequential driving, the dividing unit 12D includes a first gate clock signal (GCK1) having a phase that is different in the High period of the first shift clock signal (SCK1) or the second shift clock signal (SCK2), Alternatively, the scanning signals (Gn−1, Gn, Gn + 1...) Are sequentially output in synchronization with the second gate clock signal (GCK2).
As shown in FIG. 14, when two lines are driven simultaneously, the dividing unit 12D has the first gate clock signal (GCK1) having the same phase during the High period of the first shift clock signal (SCK1) or the second shift clock signal (SCK2). In synchronization with the second gate clock signal (GCK2), the scanning signals (Gn−1, Gn) are simultaneously output for every two lines.
The display device 100 can operate by either line-sequential driving or 2-line simultaneous driving. It is determined by setting a value in the register of the driver IC 5 from the host controller. In the case where the two-line simultaneous drive function is not provided in the gate scan circuit, the dividing unit 12D only needs to be one of the dividing circuit DVn-1 and the dividing circuit DVn.

(Shift register part)
FIG. 15 is a circuit diagram of the shift register portion of the gate scan circuit of the display device according to the example. FIG. 16 is a timing chart of the shift register portion of the gate scan circuit in the second method. FIG. 17 is a circuit diagram of a shift register section of a gate scan circuit according to a modification.
As shown in FIG. 15, the shift register circuit SRn of the shift register unit 12S includes an input node in1 to which the output of the previous shift register circuit SRn-1 is input, and an input node to which the first shift clock signal (SCK1) is input. ck1, an input node ck2 to which a second shift clock signal (SCK2) is input, an input node rs1 to which a start signal (VST) is input, and an input node rs2 to which a first control signal (VRST) is input. Furthermore, the shift register circuit SRn includes a power supply node vdd to which an intermediate voltage (DDVDH) is input and a power supply node vss to which a low voltage (VGPL) is input. Furthermore, the shift register circuit SRn outputs to the input node in1 of the dividing circuit DVn-1 and the input node in1 of the dividing circuit DVn of the dividing unit 12D, and to the input node in1 of the next-stage shift register circuit SRn + 1. The node o2, the input node in2 of the dividing circuit DVn-1, and the output node o3 output to the input node in2 of the dividing circuit DVn are provided.
The shift register circuit SRn includes a diode transistor T1 that serves as an input circuit for the output of the preceding shift register circuit SRn-1, a transistor T2 that fixes a gate electrode of a transistor T5 described later to a low voltage (VGPL), and a holding node ( The first holding node N3 includes a transistor T3 for charging, and a resetting transistor T4 for the holding node N3. Further, the shift register circuit SRn outputs a low voltage to the dividing circuits DVn-1 and DVn by the holding node N3 and a transistor T5 for outputting a high voltage to the dividing circuits DVn-1 and DVn of the dividing unit 12D. It comprises a transistor (third thin film transistor) T6, a transistor T7 that resets the holding node N3 by the output of the previous shift register circuit SRn-1, an initial reset transistor T8, and a gate electrode reset transistor T9 of the transistor T5. Yes. Further, the shift register circuit SRn includes a voltage relaxing transistor T10 that limits boosting by the transistor T5 with an intermediate voltage (DDVDH), and a transistor T11 that steps down the voltage charged by the transistor T3 with the intermediate voltage (DDVDH). Yes. Further, the shift register circuit SRn includes a transistor (third thin film transistor) T14 for outputting a High voltage to the next stage shift register circuit SRn + 1, and a transistor for outputting a Low voltage to the next stage shift register circuit SRn + 1 by the holding node N3. T15 and a transistor (first thin film transistor) T18 that charges the holding node N3 by the first control signal (VRST).
Note that the diode transistor T12 serving as an input circuit for the output of the next-stage shift register circuit SRn + 1 and the transistor T13 for resetting the holding node N3 by the output of the next-stage shift register circuit SRn + 1 are used when realizing the bidirectional scan function. . The bidirectional scanning function means that the driving order can be performed both in the forward direction and in the reverse direction so that the gate scan circuit can display even when the screen is inverted upside down. When the bidirectional scanning function is not used, the transistor T12 and the transistor T13 are unnecessary.

  The shift register circuit SRn + 1 is basically the same circuit as the shift register circuit SRn, but the input signal is partially different. The signal of the output node o2 of the previous stage shift register circuit SRn-1 is input to the input node in1 of the shift register circuit SRn. The signal of the output node o2 of the shift register circuit SRn is input to the input node in1 of the shift register circuit SRn + 1. Entered. The first shift clock signal (SCK1) is input to the input node ck1 of the shift register circuit SRn, while the second shift clock signal (SCK2) is input to the input node ck1 of the shift register circuit SRn + 1. The second shift clock signal (SCK2) is input to the input node ck2 of the shift register circuit SRn, while the first shift clock signal (SCK1) is input to the input node ck2 of the shift register circuit SRn + 1.

First, as a reset operation, the shift register circuit SRn of the shift register unit 12S inputs the high voltage of the start signal (VST) to the input node rs1, and sets the voltage of the holding node N3 to high by the transistor T8. Next, when the high voltage of the output node o2 of the pre-stage shift register circuit SRn-1 is input to the input node in1, first, the transistor T7 is turned on, and the holding node N3 is a power supply node to which a low voltage (VGPL) is input. The transistor whose gate electrode is connected to the power supply node vdd to which the intermediate voltage (DDVDH) is applied because the transistor T1 is turned on and the node N1 is maintained as the high voltage. The node N2 becomes a high voltage via T10, and the transistor T5 and the transistor T14 are turned on.
Subsequently, when the first shift clock signal (SCK1) input to the input node ck1 becomes a high voltage, the voltage of the node N2 that is the gate of the transistor T5 and the transistor T14 is further boosted by a so-called bootstrap effect, and the output node o1. After the High voltage is output, the Low voltage is output following the operation of the first shift clock signal (SCKn).
Next, since the second shift clock signal (SCK2) input to the input node ck2 becomes the high voltage, the transistor T3 is turned on, the holding node N3 is raised to the high voltage, and the transistor T9 is turned on. N1 is lowered to the Low voltage.
The node N1 lowers the node N2 to the low voltage via the transistor T10, reduces the voltage applied between the source and drain of the transistor T2, and the transistor T6 is turned on by the high voltage of the holding node N3, whereby the output node o1 The low voltage (VGPL) is connected to the power supply node vss to which the low voltage (VGPL) is input and is fixed to the low voltage.
Here, the transistor T10 has a high withstand voltage as a double gate structure in which two transistors are arranged so as to withstand a boosted voltage when the first shift clock signal (SCK1) becomes a high voltage. Similarly, the other transistors have a double gate configuration.

  As shown in FIG. 16, since the first shift clock signal (SCK1) and the second shift clock signal (SCK2) are not input in the touch detection period (Tx circuit operation period (TSP)), the first shift clock signal (SCK2) is input in the touch detection period (TSP). The holding node N3 is charged by the transistor T18 by setting the 1 control signal (VRST) to the high voltage. Thereby, the transistor T6 and the transistor T16 can be kept conductive during the touch detection period (TSP), and the output node o1 can be fixed to the Low voltage. The signal (CMCK) is a general term for a first shift clock signal (CMCK1) and a second shift clock signal (CMCK2) of a shift register unit 13SR of the common scan circuit 13 described later. When operating in the first method, the first control signal (VRST) may be fixed at a low voltage by setting a value in the register of the driver IC 5 from the host controller.

  FIG. 17 is a circuit diagram of a shift register unit of a gate scan circuit according to a modification. The shift register circuit SRAn according to the modified example deletes the transistor T14, the transistor T15, and the output node o2 from the shift register circuit SRn according to the embodiment shown in FIG. 13, and outputs to the dividing unit 12D and to the next stage shift register circuit SRn + 1. It is the structure which makes an output common. That is, the output node o1 of the shift register circuit SRAn is connected to the input node in1 of the dividing circuit DVn-1, the input node in1 of the dividing circuit DVn, and the input node in1 of the next-stage shift register circuit SRAn + 1.

(Division part)
FIG. 18 is a circuit diagram of a dividing unit of the gate scan circuit of the display device according to the example. The dividing circuit DVDn of the dividing unit 12D in FIG. 18 is a combination of the dividing circuit DVn-1 and the dividing circuit DVn in FIG. The divided circuit DVn-1 and the divided circuit DVn are basically the same circuit.
The division circuit DVDn receives an input node in1 to which a signal from the output node o1 of the shift register circuit SRn is input, an input node in2 to which a signal from the output node o3 of the shift register circuit SRn is input, and an intermediate voltage (DDVDH). Power supply node vdd, and a power supply node vss to which a low voltage (VGPL) is input. Further, the dividing circuit DVDn has an input node ck1 to which the first gate clock signal (GCK1) is input, an input node ck2 to which the second gate clock signal (GCK2) is input, and a gate signal (Gn−) to the gate line GLn−1. 1) and an output node o2 for outputting a gate signal (Gn) to the gate line GLn. The dividing circuit DVDn includes transistors T21 and T22 to which an output from the output node o1 of the shift register circuit SRn is input, and a transistor that outputs a low voltage (VGPL) as a low voltage of the gate signals (Gn−1, Gn). (Sixth thin film transistor) T23, T25, and a transistor (fifth thin film transistor) T24 that outputs the first gate clock signal (GCK1) and the second gate clock signal (GCK2) as High of the gate signals (Gn-1, Gn). And T26.
An intermediate voltage (DDVDH) is applied to the gate electrodes of the transistors T21 and T22. The transistors T21 and T22 have a role of relaxing the source-drain voltage of the transistor T6 of the shift register circuit SRn when the gate electrodes of the transistors T24 and T26 are boosted by bootstrap.
The gate electrodes of the transistors T23 and T25 are connected to the output node o3 of the shift register circuit SRn. Since the input node in2 of the dividing circuit DVDn is connected to the holding node N3 of the shift register circuit SRn charged by the second shift clock signal (SCK2) and the first control signal (VRST), the gates of the transistors T23 and T25 The electrode does not require a storage capacitor.

  The signal node (holding node N3) is charged using the first control signal (VRST) that is also output during the writing period and the next writing period (touch detection period (TSP)) to prevent leakage. Since a large storage capacitor is not added to the signal node, the storage capacitor area can be reduced, the circuit width can be reduced, and the display panel can be narrowed. In addition, since the gate scan circuit can be formed using a single channel thin film transistor, it is not necessary to use a complementary thin film transistor (CMOS), and the manufacturing process can be reduced and the cost can be reduced.

  Even when driving with a 120 Hz signal by two-line simultaneous driving, the same operation as driving with a normal 60 Hz signal can be performed. When a display device different from the present display device is driven with a 120 Hz signal, the present display device can also be line-sequentially driven with the same frequency signal. For example, a finder display of a peeping window for photographing in a high-end model such as a single-lens reflex camera is driven by a 120 Hz signal, and this display device is used for a liquid crystal display monitor and is line-sequentially driven by a 120 Hz signal. Since the liquid crystal refresh rate is improved by line-sequential driving with a 120 Hz signal, the moving image characteristics of the liquid crystal display can be improved. In addition, the time lag at the time of shutter can be reduced.

<Common scan circuit>
A common scan circuit of the display device according to the example will be described with reference to FIGS.
A power supply voltage, a clock signal, a control signal, and the like used in the common scan circuit are generated by a voltage generation circuit, a control circuit, and the like of the driver IC 5. The power supply voltage used for the common scan circuit is a high voltage (VGH) and a low voltage (VGPL). The high voltage (VGH) is the high voltage of the gate signal, and makes the transistor conductive. The low voltage (VGPL) is a low voltage of the gate signal, and shuts off the transistor.

(overall structure)
FIG. 19 is a block diagram of a common scan circuit of the display device according to the example.
As shown in FIG. 19, the common scan circuit 13 includes a shift register unit (second shift register unit) 13SR and a switch unit 13SW. The shift register unit 13SR sequentially transfers outputs in accordance with the first shift clock signal (CMCK1) and the second shift clock signal (CMCK2). The switches SW3 and SW4 of the switch unit 13SW are sequentially turned on by the transfer output. The switches SW1 and SW2 of the switch unit 13SW switch between the AC drive signal (VCOMAC) and the DC drive signal (VCOMDC) according to the first selection signal (VCOMSEL1) and the second selection signal (VCOMSEL2) to switch the common electrode signal (Cn, Cn + 1). ) Is output. In the touch sense period (TP), a DC drive signal (VCOMDC) is supplied to the common electrode to which no AC drive signal (VCOMAC) is supplied. In the writing period (PSP), the first shift clock signal (CMCK1) and the second shift clock signal (CMCK2) are not input and the shift register unit 13SR does not operate, but the DC drive signal ( VCOMDC). In FIG. 19, some of the signal lines and the like described in FIG. 20 are omitted. The gate scan circuit 12 may be arranged between the switch unit 13SW1 and the switch unit 13SW2, and the shift register 13SR, the switch unit 13SW2, the gate scan circuit 12, and the switch unit 13SW1 may be arranged in this order from the end of the display panel.

(Shift register part)
FIG. 20 is a circuit diagram of the shift register unit of the common scan circuit of the display device according to the example. FIG. 21 is a timing chart of the shift register unit of the display device according to the example.
As shown in FIG. 20, the shift register circuit CSRn of the shift register unit 13SR includes an input node in1 to which the output of the previous shift register circuit CSRn-1 is input, and an input node to which the first shift clock signal (CMCK1) is input. ck1, an input node ck2 to which a second shift clock signal (CMCK2) is input, an input node rs1 to which a start signal (CM_RST) is input, and an input node rs2 to which a second control signal (CM_RST2) is input. Further, the shift register circuit CSRn includes a power supply node vdd to which a high voltage (VGH) is input and a power supply node vss to which a low voltage (VGPL) is input. Furthermore, the shift register circuit CSRn includes an output node o1 that outputs to the input node in1 of the switch circuit CSWn of the switch unit 13SW, and an output node o2 that outputs to the input node in1 of the next-stage shift register circuit CSRn + 1.
The shift register circuit CSRn includes a diode transistor T31 serving as an input circuit from the output of the preceding stage shift register circuit CSRn-1, a transistor T32 that fixes a gate electrode of a transistor T35 described later to a low voltage (VGPL), and a node N11. And a reset transistor T34 of the holding node (second holding node) N13. Further, the shift register circuit CSRn includes a transistor T35 for outputting a high voltage to the switch circuit CSWn, a transistor (fourth thin film transistor) T36 for outputting a low voltage to the switch circuit CSW by the holding node N13, and a preceding shift register. The transistor T37 resets the holding node N3 by an input signal from the output of the circuit CSR, and an initial reset transistor T38. Further, the shift register circuit CSRn includes a voltage relaxation transistor T40 that limits boosting by the transistor T35 with a high voltage (VGH), and a transistor T42 that resets the holding node N13 by an input signal from the output of the next-stage shift register circuit CSRn + 1. It is composed of Further, the shift register circuit CSRn includes a transistor T39 for outputting a High voltage to the next stage shift register circuit CSRn + 1, a capacitor C1, and a transistor for outputting a Low voltage to the next stage shift register circuit CSRn + 1 by the holding node N13 ( (Fourth thin film transistor) T41, a capacitor C2, and a transistor (second thin film transistor) T43 that charges the holding node N13 by the second control signal (CM_RST2).
The shift register circuit CSRn + 1 is basically the same circuit as the shift register circuit CSRn, but the input signals are partially different. The signal (SROUT_n−1) of the output node o2 of the previous stage shift register circuit CSRn−1 is input to the input node in1 of the shift register circuit CSRn, but the output of the shift register circuit CSRn is input to the input node in1 of the shift register circuit CSRn + 1. A signal (SROUT_n) of the node o2 is input. The first shift clock signal (CMCK1) is input to the input node ck1 of the shift register circuit CSRn, while the second shift clock signal (CMCK2) is input to the input node ck1 of the shift register circuit CSRn + 1. The second shift clock signal (CMCK2) is input to the input node ck2 of the shift register circuit CSRn, while the first shift clock signal (CMCK1) is input to the input node ck2 of the shift register circuit CSRn + 1.

  First, as a reset operation, the shift register unit 13SR inputs the high voltage of the signal of the start signal (CM_RST) to the input node rs1, and sets the holding node N13 to the high voltage. Next, the high voltage of the output node o2 of the pre-stage shift register circuit CSRn-1 is input to the input node in1, whereby the transistor T37 and the transistor T34 are first turned on, and the node N13 is connected to the low voltage (VGPL). At the same time, the transistor T31 becomes conductive and the node N11 becomes a high voltage and is maintained, so that the node N12 becomes the high voltage via the transistor T40 to which the high voltage (VGH) is applied to the gate, and the transistor T35. Is conducted.

  Subsequently, when the first shift clock signal (CMCK1) input to the input node ck1 becomes a High voltage, the voltage of the node N12 that is the gate of the transistor T35 and the transistor T39 is further boosted by a so-called bootstrap effect, and the switch circuit CSWn. After the High voltage is output to the input node in1 and the input node in1 of the next-stage shift register circuit CSRn + 1, the Low voltage is output following the operation of the first shift clock signal (CMCK1).

  Next, when the second shift clock signal (CMCK2) becomes the high voltage, the high voltage is input to the gate of the transistor T33 from the output node o2 of the next-stage shift register circuit CSRn + 1 via the input node in2, and the transistor T33 is Conduction is performed, and the node N11 is lowered to the low voltage, and is input to the gate of the transistor T42. The transistor T42 is conducted, and the node N13 is raised to the high voltage. The node N11 lowers the node N12 to the low voltage via the transistor T40, and the transistor T36 and the transistor T41 are turned on by the high voltage of the node N13, so that the output to the output node o1 and the output node o2 is a low voltage (VGPL). And is fixed at a low voltage.

  Here, the transistor T40 has a high breakdown voltage as a double gate configuration in which two transistors are stacked so as to withstand the boosted voltage when the first shift clock signal (CMCK1) becomes a high voltage. Similarly, the other transistors have a double gate configuration.

  As shown in FIG. 21, since the first shift clock signal (CMCK1) and the second shift clock signal (CMCK2) are not input in the writing period (gate circuit operation period (PSP)), the second control signal (CM_RST2) is input during that period. ) Is set to High, the node T13 is charged by the transistor T43. As a result, the transistor T36 and the transistor T41 can be kept conductive during the writing period (PSP), and the output node o1 can be fixed to Low. The signal (SCK) is a general term for the first shift clock signal (SCK1) and the second shift clock signal (SCK2) of the shift register unit 13SR of the common scan circuit 13. In the case of operating in the first method, the second control signal (CM_RST2) may be fixed to the low voltage. It is determined by setting a value in the register of the driver IC 5 from the host controller.

(Switch part)
FIG. 22 is a circuit diagram of a switch portion of the common scan circuit of the display device according to the example. FIG. 23 is a timing chart of the switch portion of the common can circuit of the display device according to the example.
As shown in FIG. 22, the switch circuit CSWn of the switch unit 13SW includes an input node in1 to which the output of the shift register circuit CSRn is input, an input node in2 to which the first selection signal (VCOMSEL1) is input, and a second selection signal ( VCOMSEL2) is provided as an input node in3. Further, the switch circuit CSWn includes an input node rs1 to which a start signal (CM_RST) is input, an input node rs2 to which a second shift clock signal (CMCK2) is input, and an input node rs3 to which a second control signal (CM_RST2) is input. Is provided. Further, the switch circuit CSWn includes an input node in4 to which an AC drive signal (VCOMAC) is input, an input node in5 to which a DC drive signal (VCOMDC) is input, and an input node in6 to which a boost control signal (VCOMSELBST) is input. . Further, the switch circuit CSWn includes a power supply node vdd to which a high voltage (VGH) is input, a power supply node vss to which a low voltage (VGPL) is input, and an output node that outputs a common electrode signal (Cn) to the common electrode signal line CLn. out.
The switch circuit CSWn includes transistors T53 and T54 to which the output of the shift register circuit CSRn of the shift register unit 13SR is input, and transistors to which the first selection signal (VCOMSEL1) and the second selection signal (VCOMSEL2) are input. (Tenth thin film transistor) T59, a transistor T60, and boost capacitors C13 and C14. The switch circuit CSWn includes a transistor T61 that charges the holding node (third holding node) N23 to a high voltage (VGH), an initialization charging transistor T62 that holds the holding node N23, and a transistor T63 that resets the holding node N23. The node N23 includes a transistor (ninth thin film transistor) T72 and a storage capacitor C12. The switch circuit CSWn includes a transistor T64 that resets the node N21, a transistor T65 that resets the node (first node) N22, a diode transistor T66 that charges the node N22, a voltage relaxation transistor T67, and a transistor that boosts the node N22. (Eleventh thin film transistor) T71 and a boosting capacitor C15. The switch circuit CSWn includes a transistor (eighth thin film transistor) T68 that outputs an AC drive signal (VCOMAC) input to the input node in4 and a transistor (seventh transistor) that outputs a DC drive signal (VCOMDC) input to the input node in5. Thin film transistor) T69. The transistors T53 and T54 have a role of relaxing the source-drain voltage of the transistor T36 of the shift register portion 13SR when the gate electrodes of the transistors T59 and T60 are boosted by bootstrap.
The switch circuit CSWn + 1 is basically the same circuit as the switch circuit CSWn, but the input signal is partially different. The signal of the output node o1 of the shift register circuit CSRn is input to the input node in1 of the switch circuit CSWn, while the signal of the output node o1 of the shift register circuit CSRn + 1 is input to the input node in1 of the switch circuit CSWn + 1. The second shift clock signal (CMCK2) is input to the input node rs2 of the switch circuit CSWn, while the first shift clock signal (CMCK1) is input to the input node rs2 of the switch circuit CSWn + 1.
Of the switch circuit CSWn, the transistor T68, the transistor T69, the input node in4, the input node in5, and the output node out are included in the switch unit 13SW1, and the remaining transistors, capacitors, and input nodes are included in the switch unit 13SW2.

An operation in the touch detection period (TSP) will be described.
First, as a reset operation, the switch unit 13SW inputs the high voltage of the start signal (CM_RST) from the input node rs1 to the transistor T62, sets the holding node N23 to the high voltage, and resets the node N21 by the transistor T64. The node N22 is reset by the transistor T65.
Next, when the high voltage of the output node o1 of the shift register unit 13SR is input to the input node in1, the transistor T59 and the transistor T60 are turned on, and the first selection signal (VCOMSEL1) input to the input node in2 is high. When the voltage is reached, the voltage at the node N24, which is the gate of the transistor T59, is further boosted by the so-called bootstrap effect of the capacitor C13, the High voltage is output to the node N21, the node N22 is boosted as will be described later, and the transistor T68. Becomes conductive and an AC drive signal (VCOMAC) is output to the output node out. A high voltage is output to the node N21, the holding node N23 is reset by the transistor T63, and the transistor T69 is cut off.
As shown in FIG. 23, when the first selection signal (VCOMSEL1) first becomes a high voltage, the node N22 becomes a high voltage. Next, when the step-up control signal (VCOMSELBST) of the phase difference (1) input to the input node in6 becomes a high voltage, the node N22 is boosted by the transistor T71 and the capacitor C15 to a higher high voltage (one step boost). . Next, when the AC drive signal (VCOMAC) having the phase difference (3) input to the input node in4 becomes a high voltage, the node N22 is boosted by the bootstrap effect to a higher voltage (two-stage boost), and the AC drive is performed. The signal (VCOMAC) is output to the output node out. Since the switch circuit CSWn can perform two-step voltage boosting, it can cope with the lower voltage of the display panel.
When the AC drive signal (VCOMACK) becomes Low and the boost control signal (VCOMSELBST) becomes Low voltage after the phase difference (4), the node N22 is stepped down and lowered to the one-step boost level. Further, after the phase difference (4), when the first selection signal (VCOMSEL1) becomes the low voltage, the node N22 becomes the low voltage, and the transistor T68 is cut off. When the low voltage of the output node o1 of the shift register unit 13SR is input to the input node in1, the transistor T59 and the transistor T60 are cut off.
Next, when the low voltage of the output node o1 of the shift register unit 13SR is input to the input node in1, the second shift clock signal (CMCK2) input to the input node rs2 becomes a high voltage, so that the transistor T61 holds the holding node. N23 is charged to the high voltage, the node N21 is reset by the transistor T64, and the node N22 is reset by the transistor T65. The transistor T69 is turned on by the high voltage of the holding node N23, and the DC drive signal (VCOMDC) is output to the output node out. On the other hand, since the node N22 is reset, the shutoff of the transistor T68 is maintained.

The operation in the writing period (PSP) will be described.
First, as a reset operation, the switch unit 13SW inputs the high voltage of the signal of the start signal (CM_RST) to the input node rs1, sets the holding node N23 to the high voltage, resets the node N21 by the transistor T64, and The node N22 is reset by the transistor T65.
Next, when the high voltage of the output node o1 of the shift register unit 13SR is input to the input node in1, the transistor T59 and the transistor T60 are turned on, and the second selection signal (VCOMSEL2) input to the input node in3 is high. When the voltage is reached, the voltage at the node N25, which is the gate of the transistor T60, is further boosted by the so-called bootstrap effect of the capacitor C14, the High voltage is output to the node N23, and the transistor T69 is turned on and input to the input node in5. A direct current drive signal (VCOMDC) is output to the output node out. Since the High voltage is output to the node N23, the node N21 is reset by the transistor T64, and the node N22 is reset by the transistor T65. Since node N22 has been reset, transistor T68 is cut off.
Next, when the Low voltage of the output node o1 of the shift register unit 13SR is input to the input node in1, the second shift clock signal (CMCK2) becomes the High voltage, so that the holding node N23 is charged to the High voltage by the transistor T61. The conduction of the transistor T69 and the cutoff of the transistor T68 are maintained, and the DC drive signal (VCOMDC) is output to the output node out.
However, as shown in FIG. 21, since the first shift clock signal (CMCK1) and the second shift clock signal (CMCK2) are not input during the writing period (gate circuit operation period (PSP)), the input node rs3 is input during that period. By setting the input second control signal (CM_RST2) to the High voltage, the transistor T72 charges the holding node N23 to the High voltage. The transistor T69 is turned on by the high voltage of the holding node N23, and the DC drive signal (VCOMDC) is output to the common electrode. In the case of operating in the first method, the second control signal (CM_RST2) may be fixed to the low voltage by setting a value in the register of the driver IC 5 from the host controller. Note that the transistor T62 may not be provided depending on a circuit configuration.

  The signal node is charged using the clock signal that is also output between the touch detection period and the next touch detection period (writing period (PSP)) to prevent leakage. Since a large storage capacitor is not added to the signal node, the storage capacitor area can be reduced, the circuit width can be reduced, and the display panel can be narrowed. In addition, since a common scan circuit can be formed using a single channel thin film transistor, it is not necessary to use a complementary thin film transistor (CMOS), the manufacturing process can be reduced, and the cost can be reduced.

DESCRIPTION OF SYMBOLS 1 ... Display panel 2 ... Backlight 5 ... Driver IC
6 ... Flexible wiring board 7 ... Flexible wiring board 8 ... Connection portion 9 ... Connector 10 ... Array substrate 11 ... Common electrode 12 ... Gate scan circuit (GIP)
13 ... Common scan circuit (Tx)
13SR: Shift register section (Tx (S / R))
13SW ・ ・ ・ Switch part (Tx (SW))
DESCRIPTION OF SYMBOLS 14 ... Input terminal 15 ... Pixel part 20 ... Counter substrate 21 ... Detection electrode 30 ... Liquid crystal layer 40 ... Polarizing plate 50 ... Polarizing plate 100 ... Display device CL1, CLn ... common lines DL1, DLm ... drain lines GL1, GLk ... gate lines Pmk ... pixel regions PT11, PTm1, PT1k, PTmk ... pixel electrodes TR11, TRm1, TR1k, TRmk ... Thin film transistors TDL1, TDLj..., Detection electrode signal lines SRn, SRn... Shift register circuit SR1A... Shift register circuits DVn-1, DVn, DVn + 1, DVn + 2 ... division circuit DVDn ... division circuits CSRn, CSRn + 1 ... Shift register circuits CSWn, CSWn + 1 ... Switch circuit

Claims (19)

The display device
A counter electrode in which a common electrode for display and a scanning electrode for touch detection are shared,
A first scanning circuit for scanning a gate line;
A second scanning circuit for scanning the counter electrode;
With
The display device
A second mode having a writing period for continuously scanning one screen within one frame period, and a touch detection period between the writing period and the writing period of the next frame;
A first mode in which a writing period and a touch detection period alternately appear multiple times within one frame period;
Have
The first scanning circuit has a first shift register unit;
The second scanning circuit includes a second shift register unit and a switch unit,
The first scanning circuit is disposed between the second shift register unit and the switch unit in plan view,
Each of the first scanning circuit and the second scanning circuit is composed of a single channel thin film transistor. The display device according to claim 1.
During the write period of the second mode, a first control signal for fixing the output node of the first shift register unit is input. The display device according to claim 2.
The first shift register unit includes a thin film transistor for charging an internal node according to the first control signal. The display device according to claim 1.
During the touch detection period of the second mode, a second control signal for fixing the output node of the second shift register unit is input. The display device according to claim 4.
The second shift register unit includes a thin film transistor for charging an internal node according to the second control signal. The display device according to claim 1.
The counter substrate has detection electrodes for touch detection. The display device
An array substrate;
A counter substrate;
A control circuit;
With
The array substrate is
A counter electrode in which the common electrode for display and the scan electrode for touch detection are shared, and
A first scanning circuit for scanning a gate line;
A second scanning circuit for scanning the counter electrode;
With
The display device has a writing period for continuously scanning one screen within one frame period, and a touch detection period between the writing period and a writing period of the next frame,
The first scanning circuit includes a first shift register unit, and scans the gate line during the writing period.
The second scanning circuit includes a second shift register unit, and scans the touch detection scanning electrode during the touch detection period.
The first scanning circuit and the second scanning circuit are each composed of a single channel thin film transistor,
The control circuit outputs a first control signal for fixing a first output node of the first shift register unit during the touch detection period,
The control circuit outputs a second control signal for fixing the second output node of the second shift register unit during the writing period. The display device according to claim 7.
The first shift register unit includes a first thin film transistor for charging a first holding node according to the first control signal.
The second shift register unit includes a second thin film transistor for charging a second holding node according to the second control signal. The display device according to claim 8.
The output node of the first shift register unit is fixed to Low by the charged first holding node,
The output node of the second shift register unit is fixed to Low by the charged second holding node. The display device according to claim 9.
The first shift register unit includes a third thin film transistor that outputs a low voltage to an output node of the first shift register unit, and the first holding node is connected to a gate electrode of the third thin film transistor;
The second shift register unit includes a fourth thin film transistor that outputs a low voltage to an output node of the second shift register unit, and the second holding node is connected to a gate electrode of the fourth thin film transistor. The display device according to claim 7.
The first scanning circuit has a function of simultaneously driving a plurality of gate lines and a function of line-sequential driving. The display device according to claim 11.
The first scanning circuit has a dividing circuit unit having a function of outputting to the gate line. The display device of claim 12,
The shift register unit sequentially operates according to a first shift clock signal and a second shift clock signal having different phases. The display device according to claim 13,
At the time of line sequential driving, the dividing unit sequentially outputs to the gate lines in synchronization with the first gate clock signal or the second gate clock signal having different phases in the High period of the first shift clock signal or the second shift clock signal. The display device according to claim 14, wherein
The dividing unit includes a fifth thin film transistor that outputs High to the gate line and a sixth thin film transistor that outputs Low to the gate line, and the gate electrode of the sixth thin film transistor is charged by the second shift clock signal. Is done. The display device according to claim 13,
At the time of simultaneous driving, the dividing unit simultaneously outputs to the two gate lines in synchronization with the first gate clock signal or the second gate clock signal having the same phase during the High period of the first shift clock signal or the second shift clock signal. . The display device according to claim 16, wherein
The dividing unit includes a fifth thin film transistor that outputs High to the gate line and a sixth thin film transistor that outputs Low to the gate line, and the gate electrode of the sixth thin film transistor is charged by the second shift clock signal. Is done. The display device according to claim 7.
It is possible to operate in a mode in which the writing period and the touch detection period alternately appear a plurality of times within one frame period. The display device according to claim 7.
The second scanning circuit has a switch part,
The first scanning circuit is disposed between the second shift register unit and the switch unit in plan view.

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