JP2021157772A - Display system, control device, and control method - Google Patents

Abstract

To provide a technique of achieving further improvement in a display system.SOLUTION: A first display device 22a includes a plurality of first sensor electrodes. A second display device 22b is disposed adjacent to the first display device 22a, and includes a plurality of second sensor electrodes. A first driving circuit 74a supplies a first touch driving signal to the first sensor electrodes. A second driving circuit 74b supplies a second touch driving signal having the same frequency as the first touch driving signal and having the phase aligned with that of the first touch driving signal to the second sensor electrodes.SELECTED DRAWING: Figure 1

Description

The present invention relates to a display system, a control device, and a control method having a touch detection function.

In recent years, a display input device equipped with a touch display that displays a GUI on a display screen and inputs instructions by directly touching the display screen with a user's finger or the like has become widespread (see, for example, Patent Documents 1 and 2). .. This type of display input device is widely used in mobile terminals and terminals with limited installation space because the configuration can be simplified compared to a display input device that has a separate input unit such as a button or keyboard for the display device. ing.

Japanese Unexamined Patent Publication No. 2014-132445 Japanese Unexamined Patent Publication No. 2016-200886

Further improvements are needed in display systems with touch displays.

In order to solve the above problems, the display system of an embodiment of the present invention has a first display device having a plurality of first sensor electrodes and a plurality of second sensor electrodes arranged adjacent to the first display device. The second display device, the first drive circuit that supplies the first touch drive signal to the plurality of first sensor electrodes, and the frequency that is the same as the frequency of the first touch drive signal and with respect to the first touch drive signal. An object to the first display device based on the second drive circuit that supplies the second touch drive signal having the same phase to the plurality of second sensor electrodes and the touch detection signals received from each of the plurality of first sensor electrodes. A first touch detection circuit for detecting the touch of the object and a second touch detection circuit for detecting the touch of an object to the second display device based on the touch detection signals received from each of the plurality of second sensor electrodes. ..

Another aspect of the invention is also a display system. This display system displays a first display device having a plurality of first sensor electrodes, a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes, and a first touch drive signal. A first drive circuit that supplies a plurality of first sensor electrodes, a second drive circuit that supplies a second touch drive signal having the same frequency as the frequency of the first touch drive signal to the plurality of second sensor electrodes, and a plurality of second drives. A first touch detection circuit that integrates the touch detection signals received from each of the one sensor electrodes during the first period and detects the touch of an object on the first display device based on the integrated value, and a plurality of second sensor electrodes. It is provided with a second touch detection circuit that integrates the touch detection signals received from each of the above for the second period and detects the touch of the object to the second display device based on the integrated value. The first touch drive signal and the second touch drive signal change between the first voltage and the second voltage, respectively, and the first period and the second period, respectively, are the first touch drive signal and the second touch drive. Of the signals, the one whose phase is advanced includes the period from the first timing to the second timing when the first voltage changes to the second voltage. In the second timing, the phase of the first touch drive signal and the second touch drive signal, which is delayed in phase, changes from the first voltage to the second voltage, so that the first sensor electrode and the first sensor electrode of the adjacent first display device and the second timing are used. 2 This is the timing when the current flowing between the display device and the second sensor electrode becomes zero. The timing at which the second touch drive signal changes from the first voltage to the second voltage and the second timing are between the first timing and the timing at which the first touch drive signal changes from the second voltage to the first voltage. To position.

Yet another aspect of the present invention is a control device. This device is a control device that controls a first display device having a plurality of first sensor electrodes and a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes. , The first drive circuit that supplies the first touch drive signal to the plurality of first sensor electrodes, and the first that has the same frequency as the frequency of the first touch drive signal and is in phase with the first touch drive signal. A second drive circuit that supplies a two-touch drive signal to a plurality of second sensor electrodes, and a second that detects a touch of an object on the first display device based on touch detection signals received from each of the plurality of first sensor electrodes. It includes a one-touch detection circuit and a second touch detection circuit that detects a touch of an object on a second display device based on touch detection signals received from each of a plurality of second sensor electrodes.

Yet another aspect of the present invention is a control method. This method is a control method for controlling a first display device having a plurality of first sensor electrodes and a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes. , The step of supplying the first touch drive signal to the plurality of first sensor electrodes, and the second touch drive having the same frequency as the frequency of the first touch drive signal and having the same phase as the first touch drive signal. A step of supplying a signal to a plurality of second sensor electrodes, a step of detecting a touch of an object on the first display device based on a touch detection signal received from each of the plurality of first sensor electrodes, and a plurality of second steps. It includes a step of detecting the touch of an object on the second display device based on the touch detection signals received from each of the sensor electrodes.

Further improvement can be realized by the above aspect.

It is a block diagram of the display system which concerns on 1st Embodiment. It is a figure which shows schematic the circuit structure of the display device of FIG. It is a top view which shows the arrangement of the common electrode of FIG. It is a vertical sectional view of the display device of FIG. It is a figure which shows the timing of the 1st frame period in the 1st display device, and the timing of the 2nd frame period in a 2nd display device. FIG. 6A is a diagram for explaining the operation of the display device in the first touch detection period T1a of FIG. 5, and FIG. 5B is a diagram for explaining the operation of the display device in the first touch detection period T2a. Is. FIG. 7A is a diagram for explaining the operation of the display device in the first touch detection period T3a, and FIG. 7B is a diagram for explaining the operation of the display device in the first touch detection period T4a. It is an equivalent circuit diagram of the common electrode of the 1st display device and the common electrode of the 2nd display device adjacent to each other. It is a figure which shows an example of the waveform of the 1st touch drive signal TX1, the 2nd touch drive signal TX2, the voltage VCp and the current ICp of FIG. It is a figure which shows an example of the waveform of the 1st touch drive signal TX1, the 2nd touch drive signal TX2, the voltage VCp and the current ICp of the display system of the comparative example. It is a block diagram of the display system which concerns on 2nd Embodiment. It is a figure which shows an example of the waveform of the timing signal ST and the 1st touch drive signal TX1 of the display system of FIG. It is a block diagram of the display system which concerns on 3rd Embodiment. It is a figure which shows an example of the waveform of the 1st touch drive signal TX1, the 2nd touch drive signal TX2, and the current ICp which concerns on 3rd Embodiment. It is a flowchart which shows the activation process of the display system of FIG. It is a block diagram of the display system which concerns on 4th Embodiment. It is a flowchart which shows the activation process of the display system which concerns on the 2nd modification of 4th Embodiment. It is a flowchart which shows the output process of the synchronization signal SY of the 1st display control apparatus which concerns on 6th Embodiment. It is a block diagram of the display system which concerns on 7th Embodiment.

(Knowledge on which this disclosure was based)
Before concretely explaining the embodiment, the basic findings will be explained. In some cases, two touch displays that detect the touch position by the self-capacity method are arranged side by side to form a large-screen touch display. The two touch displays are placed in contact with each other so that the boundary is inconspicuous. In this case, the present inventor has found a problem that there is a possibility that a touch is erroneously detected near the boundary between two touch displays even if there is no touch. In order to solve this problem, the display system according to the present disclosure is configured as follows.

Hereinafter, the same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and redundant description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are shown enlarged or reduced as appropriate for easy understanding.

(First Embodiment)
FIG. 1 is a block diagram of the display system 1 according to the first embodiment. The display system 1 will be described as an example of an in-vehicle display system 1 mounted on a vehicle such as an automobile, but the application is not particularly limited and may be used for a mobile device or the like.

The display system 1 includes a host 10, a first display module 20a, and a second display module 20b. Hereinafter, when the first display module 20a and the second display module 20b are not distinguished, they are referred to as a display module 20. The display module 20 is also called a display panel.

The host 10 executes various functions such as radio, car navigation, and Bluetooth (registered trademark) communication, and controls two display modules 20. The host 10 includes a control device 12. The host 10 is arranged on a substrate different from the first display module 20a and the second display module 20b, for example.

The control device 12 is, for example, a CPU, and is also called a host CPU. The control device 12 supplies the image data DD and the control data CD to the two display modules 20, and controls the two display modules 20 based on these data.

The first display module 20a includes a first display device 22a and a first display control device 24a. The second display module 20b includes a second display device 22b and a second display control device 24b. Hereinafter, when the first display device 22a and the second display device 22b are not distinguished, they are referred to as a display device 22, and when the first display control device 24a and the second display control device 24b are not distinguished, they are referred to as a display control device 24. ..

The two display devices 22 are used, for example, as a center display in a vehicle interior on which a car navigation screen or the like is displayed, and are arranged adjacent to each other in the horizontal direction or the vertical direction. The two display devices 22 are arranged side by side with almost no gap. The two display devices 22 may each display a part of one screen such as a car navigation screen to form one screen with two screens, or one of them may display a first screen such as a car navigation screen. A second screen, such as a television screen, which is displayed and the other screen is different from the first screen, may be displayed.

The display device 22 is an in-cell type IPS (In Plane Switching) type liquid crystal display device, which is configured as a touch display and can detect a touch position. The configuration of the display device 22 is, for example, a well-known configuration described below.

FIG. 2 schematically shows a circuit configuration of the display device 22 of FIG. FIG. 2 also shows the schematic arrangement of each component. The display device 22 includes a plurality of gate lines G1, G2, ... Extending in the row direction, a plurality of source lines S1, S2, ... Extending in the column direction, a plurality of pixel switching elements 30, and a plurality of pixels. The electrode 32 and a plurality of common electrodes 34 are provided. Each pixel switching element 30 is a thin film transistor and is provided in the vicinity of the intersection of the gate line and the source line corresponding to the pixels. In each pixel switching element 30, a gate wire is connected to the gate, a source wire is connected to the source, and a pixel electrode 32 is connected to the drain. A plurality of pixel switching elements 30 and a plurality of pixel electrodes 32 are arranged with respect to one common electrode 34. The liquid crystal layer is controlled by the electric field between the pixel electrode 32 and the common electrode 34. The common electrode 34 is shared for image display and touch detection. Therefore, the number of layers of the electrodes can be reduced to make the display device 22 thinner. The common electrode 34 of the first display device 22a can also be called a first sensor electrode. The common electrode 34 of the second display device 22b can also be called a second sensor electrode.

FIG. 3 is a top view showing the arrangement of the common electrodes 34 of FIG. The plurality of common electrodes 34 are arranged in a matrix. Each common electrode 34 of the first display device 22a is connected to the first display control device 24a by a signal line 36, and each common electrode 34 of the second display device 22b is connected to the second display control device 24b by a signal line 36. Will be done.

The display device 22 detects the touch position by the self-capacity method. When a finger approaches the display surface of the display device 22, a capacitance is generated between the common electrode 34 and the finger. When the capacitance is generated, the parasitic capacitance in the common electrode 34 increases, and the current for supplying the touch drive signal to the common electrode 34 increases. The touch position is detected based on the amount of fluctuation of this current.

FIG. 4 is a vertical cross-sectional view of the display device 22 of FIG. The display device 22 includes a backlight unit 40, a lower polarizing plate 42, a thin film transistor substrate (hereinafter referred to as a TFT substrate) 44, a liquid crystal layer 52, a color filter substrate 54, and upper polarized light, which are arranged in order along the thickness direction. A plate 56, a bonding layer 58, and a protective layer 60 are provided.

In the following description, in the thickness direction of the display device 22, the side where the protective layer 60 is located with respect to the TFT substrate 44 is the front side, and the opposite is the back side.

The display device 22 uses the light emitted from the backlight unit 40 to emit the image light to the front side, that is, to the observer side.

The TFT substrate 44 has a glass substrate 46, a plurality of gate electrodes 48 arranged on the front side of the glass substrate 46, a plurality of source electrodes 50, and a plurality of common electrodes 34. Although not shown, the TFT substrate 44 includes a plurality of gate lines G1, G2, ..., a plurality of source lines S1, S2, ..., a plurality of pixel electrodes 32, and a plurality of pixel switching elements 30 in FIG. Also has. The liquid crystal layer 52 arranged on the front surface side of the TFT substrate 44 is controlled by a lateral electric field generated between the pixel electrode 32 and the common electrode 34.

The bonding layer 58 has translucency and bonds the upper polarizing plate 56 and the protective layer 60. The bonding layer 58 is, for example, a cured liquid transparent resin such as OCR (Optically Clear Resin) or a transparent adhesive sheet such as OCA (Optically Clear Adhesive).

The protective layer 60 is a light-transmitting layer for protecting the display device 22, and is composed of a glass substrate, a plastic substrate, or the like. The protective layer 60 is also called a cover lens or the like.

Return to FIG. The first display control device 24a is configured as, for example, an IC, and controls the first display device 22a according to the control data CD and the image data DD from the host 10. The first display control device 24a includes a first control circuit 70a, a third drive circuit 72a, a first drive circuit 74a, a first touch detection circuit 76a, and a first clock generation circuit 78a.

The first control circuit 70a is composed of, for example, a microcomputer, and controls signal generation of the first clock generation circuit 78a, the third drive circuit 72a, the first drive circuit 74a, the operation timing of the first touch detection circuit 76a, and the like.

In the first control circuit 70a, the third drive circuit 72a, so that one frame of the display image is drawn on the first display device 22a and the touch detection of one screen is executed at least once during the first frame period. It controls the first drive circuit 74a and the first touch detection circuit 76a. The first frame period can also be called the first vertical synchronization period. The details of the first frame period will be described later.

The first clock generation circuit 78a generates the first reference clock signal CK1 according to the control of the first control circuit 70a. The third drive circuit 72a generates a source signal SS based on the image data DD from the host 10 and the generated first reference clock signal CK1 according to the control of the first control circuit 70a. The third drive circuit 72a generates a gate signal GS based on the generated first reference clock signal CK1 according to the control of the first control circuit 70a.

The third drive circuit 72a sequentially supplies the source signal SS to the plurality of source lines of the first display device 22a, and sequentially supplies the gate signal GS to the plurality of gate lines of the first display device 22a.

The first drive circuit 74a generates a reference voltage VCOM which is a predetermined fixed voltage according to the control of the first control circuit 70a, and is a first touch drive synchronized with the generated first reference clock signal CK1. Generate signal TX1. The phase of the first touch drive signal TX1 is aligned with the phase of the first reference clock signal CK1. The first touch drive signal TX1 may be a rectangular wave or a sine wave. The first drive circuit 74a supplies the reference voltage VCOM or the first touch drive signal TX1 to the entire plurality of common electrodes 34 of the first display device 22a via the signal line 36 of FIG.

The first touch detection circuit 76a detects the touch of an object on the first display device 22a. The first touch detection circuit 76a follows the control of the first control circuit 70a, and is based on the touch detection signal RX received from the common electrode 34 when the first touch drive signal TX1 is supplied to each common electrode 34. The touch of the object to the position corresponding to the common electrode 34 is detected.

The first touch detection circuit 76a integrates the touch detection signal RX received from each common electrode 34 for a predetermined reference time from the rise of the pulse for each pulse of the first touch drive signal TX1, and integrates the integrated value and the reference value. Derivation of the difference value with. The first touch detection circuit 76a integrates the touch detection signal RX received from each common electrode 34 from the fall of the pulse to the reference time for each pulse of the touch drive signal TX, and the difference between the integrated value and the reference value. Derived the value. A difference value may be derived for either the rising edge or the falling edge of the pulse. With respect to the touch detection signal RX received from one common electrode 34 in one touch detection period, a difference value of a number proportional to the number of pulses of the first touch drive signal TX1 in one touch detection period is obtained. Each value represents a difference value between the capacitance of the common electrode 34 and the reference capacitance. The first touch detection circuit 76a calculates a value obtained by averaging these difference values as a detection value for each common electrode 34. The larger the amount of change in the capacitance of the common electrode 34 due to the touch of an object, the larger the detected value. If there is no touch and the amount of change in the capacitance of the common electrode 34 is zero, the detected value is zero.

The first touch detection circuit 76a compares the detection value based on the touch detection signal RX received from each common electrode 34 with a predetermined touch detection threshold value, and when the detection value is equal to or greater than the touch detection threshold value, the position of the common electrode 34 is reached. It is determined that there is a touch on. This corresponds to the detection of a touch. The first touch detection circuit 76a detects the touch position in the screen based on the position of the common electrode 34 determined to have touch. The first touch detection circuit 76a outputs the detected touch position information to the first control circuit 70a.

The first control circuit 70a derives the coordinate data TD of the touch position based on the information of the touch position from the first touch detection circuit 76a, and outputs the coordinate data TD to the control device 12 of the host 10. The control device 12 executes various processes according to the coordinate data TD.

The first clock generation circuit 78a generates a synchronization signal SY synchronized with the first reference clock signal CK1, and outputs the synchronization signal SY to the second display control device 24b at each start timing of the first frame period, for example. For example, the synchronization signal SY is a pulse that rises at the start timing of the first frame period, and its phase is aligned with the phase of the first reference clock signal CK1. The output timing of the synchronization signal SY is not particularly limited as long as the signal can be synchronized between the first display control device 24a and the second display control device 24b. The wiring for transmitting the synchronization signal SY is connected from the first display control device 24a to the second display control device 24b via the substrate on which the host 10 is arranged.

The second display control device 24b is configured as, for example, an IC, and controls the second display device 22b according to the control data CD and the image data DD from the host 10 and the synchronization signal SY from the first display control device 24a. The basic operation of the second display control device 24b is common to the operation of the first display control device 24a. The second display control device 24b includes a second control circuit 70b, a fourth drive circuit 72b, a second drive circuit 74b, a second touch detection circuit 76b, and a second clock generation circuit 78b.

The second control circuit 70b is composed of, for example, a microcomputer, and based on the synchronization signal SY, the signal generation of the second clock generation circuit 78b, the fourth drive circuit 72b, and the second drive circuit 74b, and the operation of the second touch detection circuit 76b. Control the timing and so on. The second control circuit 70b and the above-mentioned first control circuit 70a can be collectively called a control circuit.

In the second control circuit 70b, the fourth drive circuit 72b, so that one frame of the display image is drawn on the second display device 22b and the touch detection on one screen is executed at least once during the second frame period. It controls the second drive circuit 74b and the second touch detection circuit 76b. The second control circuit 70b controls so that the start timing of the second frame period coincides with the start timing of the first frame period based on the synchronization signal SY. The second frame period can also be called the second vertical synchronization period. The details of the second frame period will be described later.

The second clock generation circuit 78b generates a second reference clock signal CK2 having the same frequency as the frequency of the first reference clock signal CK1 synchronized with the first reference clock signal CK1 according to the control of the second control circuit 70b. The phase of the second reference clock signal CK2 is aligned with the phase of the first reference clock signal CK1. The fourth drive circuit 72b generates a source signal SS based on the image data DD from the host 10 and the generated second reference clock signal CK2 according to the control of the second control circuit 70b. The fourth drive circuit 72b generates a gate signal GS based on the generated second reference clock signal CK2 according to the control of the second control circuit 70b.

The fourth drive circuit 72b sequentially supplies the source signal SS to the plurality of source lines of the second display device 22b, and sequentially supplies the gate signal GS to the plurality of gate lines of the second display device 22b.

The second drive circuit 74b generates a reference voltage VCOM according to the control of the second control circuit 70b, and generates a second touch drive signal TX2 synchronized with the generated second reference clock signal CK2. The second touch drive signal TX2 and the first touch drive signal TX1 have the same amplitude and the same frequency. The phase of the second touch drive signal TX2 is aligned with the phase of the second reference clock signal CK2. Therefore, the second touch drive signal TX2 is in phase with the first touch drive signal TX1. The second touch drive signal TX2 may be a rectangular wave or a sine wave. The second drive circuit 74b supplies the reference voltage VCOM or the second touch drive signal TX2 to the entire plurality of common electrodes 34 of the second display device 22b via the signal line 36 of FIG.

The second touch detection circuit 76b detects the touch of an object on the second display device 22b. The second touch detection circuit 76b follows the control of the second control circuit 70b, and is based on the touch detection signal RX received from the common electrode 34 when the second touch drive signal TX2 is supplied to each common electrode 34. The touch of the object to the position corresponding to the common electrode 34 is detected. The specific operation is the same as that of the first touch detection circuit 76a. The second touch detection circuit 76b outputs the detected touch position information to the second control circuit 70b.

The second control circuit 70b derives the coordinate data TD of the touch position based on the information of the touch position from the second touch detection circuit 76b, and outputs the coordinate data TD to the control device 12.

The configuration of the control device 12, the first control circuit 70a, and the second control circuit 70b can be realized by the cooperation of the hardware resource and the software resource, or only by the hardware resource. Analog devices, microcomputers, DSPs, ROMs, RAMs, FPGAs, and other LSIs can be used as hardware resources. Programs such as firmware can be used as software resources.

FIG. 5 shows the timing of the first frame period Fa in the first display device 22a and the second frame period Fb in the second display device 22b.

The first frame period Fa includes four first display periods Da and four first touch detection periods T1a, T2a, T3a, and T4a. The first display period Da and the first touch detection period are arranged alternately. In the first frame period Fa, the first display period Da, the first touch detection period T1a, the first display period Da, the first touch detection period T2a, the first display period Da, the first touch detection period T3a, the first display period. Da and the first touch detection period T4a are arranged in this order.

The second frame period Fb includes four second display periods Db and four second touch detection periods T1b, T2b, T3b, and T4b. The second display period Db and the second touch detection period are arranged alternately. In the second frame period Fb, the second display period Db, the second touch detection period T1b, the second display period Db, the second touch detection period T2b, the second display period Db, the second touch detection period T3b, and the second display period. Db and the second touch detection period T4b are arranged in this order.

The length of the first display period Da is equal to the length of the second display period Db. The lengths of the first touch detection periods T1a to T4a and the lengths of the second touch detection periods T1b to T4b are equal. The length of the first frame period Fa is equal to the length of the second frame period Fb. The start timing (time t0) of the first frame period Fa coincides with the start timing of the second frame period Fb. In the first touch detection period and the second touch detection period corresponding to one-to-one, the start timings and the end timings match.

The number of the first display period Da and the number of the first touch detection period of the first frame period Fa, the number of the second display period Db and the number of the second touch detection period of the second frame period Fb are set to "4", respectively. Not limited.

The first display device 22a displays 1/4 of one frame for each first display period Da. One frame is displayed by the four first display periods Da of the first frame period Fa. Specifically, during the first display period Da, the third drive circuit 72a supplies the source signal SS to the plurality of source lines, supplies the gate signal GS to the target gate line, and the first drive circuit 74a has a plurality of. The reference voltage VCOM is supplied to the common electrode 34 of the above. The first drive circuit 74a stops the supply of the first touch drive signal TX1 during the first display period Da.

The second display device 22b displays 1/4 of one frame for each second display period Db. One frame is displayed by the four second display periods Db of the second frame period Fb. Specifically, during the second display period Db, the fourth drive circuit 72b supplies the source signal SS to the plurality of source lines, supplies the gate signal GS to the target gate line, and the second drive circuit 74b has a plurality of. The reference voltage VCOM is supplied to the common electrode 34 of the above. The second drive circuit 74b stops the supply of the second touch drive signal TX2 during the second display period Db.

FIG. 6A is a diagram illustrating the operation of the display device 22 during the first touch detection period T1a of FIG. The first display device 22a and the second display device 22b are arranged adjacent to each other in the horizontal direction when viewed from the observer.

The first display device 22a includes first touch detection areas R4a, R3a, R2a, and R1a arranged in order toward the second display device 22b. That is, the first touch detection regions R1a, R2a, R3a, and R4a are arranged in the horizontal direction, which is the direction along the arrangement direction of the first display device 22a and the second display device 22b. The rightmost first touch detection area R1a is adjacent to the second display device 22b. A plurality of common electrodes 34 of the first display device 22a are arranged in each of the first touch detection regions R1a to R4a.

The second display device 22b includes second touch detection areas R1b, R2b, R3b, and R4b arranged in order away from the first display device 22a. That is, the second touch detection regions R1b, R2b, R3b, and R4b are arranged in the horizontal direction. The leftmost second touch detection area R1b is adjacent to the first display device 22a. A plurality of the plurality of common electrodes 34 of the second display device 22b are arranged in each of the second touch detection regions R1b to R4b. The number of touch detection areas of one display device 22 is not limited to "4".

The first drive circuit 74a supplies the first touch drive signal TX1 to the entire plurality of common electrodes 34 of the first display device 22a during the first touch detection period T1a. The first touch detection circuit 76a shifts to the first touch detection region R4a based on the touch detection signals RX received from the plurality of common electrodes 34 of the first touch detection region R4a to be detected during the first touch detection period T1a. Detects the touch of an object.

The second drive circuit 74b supplies the second touch drive signal TX2 to the entire plurality of common electrodes 34 of the second display device 22b during the second touch detection period T1b. The second touch detection circuit 76b shifts to the second touch detection region R1b based on the touch detection signals RX received from the plurality of common electrodes 34 of the second touch detection region R1b to be detected during the second touch detection period T1b. Detects the touch of an object.

FIG. 6B is a diagram illustrating the operation of the display device 22 during the first touch detection period T2a. Since the operations of the first drive circuit 74a and the second drive circuit 74b during each touch detection period are common, the description thereof will be omitted below. The first touch detection circuit 76a is located in the first touch detection region R3a based on the touch detection signals RX received from the plurality of common electrodes 34 of the first touch detection region R3a to be detected during the first touch detection period T2a. Detect touch.

The second touch detection circuit 76b is in the second touch detection region R2b based on the touch detection signals RX received from the plurality of common electrodes 34 of the second touch detection region R2b to be detected during the second touch detection period T2b. Detect touch.

FIG. 7A is a diagram illustrating the operation of the display device 22 during the first touch detection period T3a. The first touch detection circuit 76a is located in the first touch detection region R2a based on the touch detection signals RX received from the plurality of common electrodes 34 of the first touch detection region R2a to be detected during the first touch detection period T3a. Detect touch.

The second touch detection circuit 76b is in the second touch detection region R3b based on the touch detection signals RX received from the plurality of common electrodes 34 of the second touch detection region R3b to be detected during the second touch detection period T3b. Detect touch.

FIG. 7B is a diagram illustrating the operation of the display device 22 during the first touch detection period T4a. The first touch detection circuit 76a is in the first touch detection region R1a based on the touch detection signals RX received from the plurality of common electrodes 34 of the first touch detection region R1a to be detected during the first touch detection period T4a. Detect touch.

The second touch detection circuit 76b is in the second touch detection region R4b based on the touch detection signals RX received from the plurality of common electrodes 34 of the second touch detection region R4b to be detected during the second touch detection period T4b. Detect touch.

In this way, the first touch detection circuit 76a detects touches in different first touch detection regions for each first touch detection period. The touch detection on one screen is executed once by the four first touch detection periods of the first frame period Fa.

The second touch detection circuit 76b detects touches in a second touch detection region that is different for each second touch detection period. The touch detection on one screen is executed once by the four second touch detection periods of the second frame period Fb.

FIG. 8 is an equivalent circuit diagram of the common electrode 34 of the adjacent first display device 22a and the common electrode 34 of the second display device 22b. The resistor Ra is a wiring resistance of the signal line 36 connected to the common electrode 34 of the first display device 22a. The capacitance C1a is a parasitic capacitance with respect to the ground potential of the common electrode 34 of the first display device 22a, and corresponds to the reference capacitance described above.

The resistor Rb is a wiring resistance of the signal line 36 connected to the common electrode 34 of the second display device 22b. The capacitance C1b is a parasitic capacitance with respect to the ground potential of the common electrode 34 of the second display device 22b, and corresponds to a reference capacitance.

The capacitance Cp is a parasitic capacitance between the common electrode 34 of the adjacent first display device 22a and the common electrode 34 of the second display device 22b. Since the two display devices 22 are arranged with almost no gap so that the boundary is inconspicuous as described above, a parasitic capacitance is generated between these common electrodes 34.

The first touch drive signal TX1 is supplied to one end of the capacitance Cp via the resistor Ra. The second touch drive signal TX2 is supplied to the other end of the capacitance Cp via the resistor Rb. The voltage VCp is the voltage between both ends of the capacitance Cp, and the current ICp is the current flowing through the capacitance Cp.

FIG. 9 shows an example of the waveforms of the first touch drive signal TX1, the second touch drive signal TX2, the voltage VCp, and the current ICp of FIG.

The first touch drive signal TX1 and the second touch drive signal TX2 have the same phase, the same frequency, and the same amplitude. The rising timing and the falling timing match between the first touch drive signal TX1 and the second touch drive signal TX2. Therefore, no potential difference is generated between both ends of the capacitance Cp, and the voltage Vcp is substantially maintained at 0V. Therefore, the current ICp is substantially 0A.

Here, a comparative example will be described. FIG. 10 shows an example of waveforms of the first touch drive signal TX1, the second touch drive signal TX2, the voltage VCp, and the current ICp of the display system of the comparative example.

In the comparative example, the first touch drive signal TX1 and the second touch drive signal TX2 are different in phase from the present embodiment. That is, in the comparative example, the rising timing is different and the falling timing is different between the first touch drive signal TX1 and the second touch drive signal TX2. Therefore, there is a period in which a potential difference is generated between both ends of the capacitance Cp, and the voltage VCp changes periodically between positive and negative. Therefore, the current ICp that charges and discharges the parasitic capacitance Cp flows periodically. In the first display device, the current ICp is added to the current that charges the parasitic capacitance with respect to the ground potential of the common electrode adjacent to the second display device, resulting in a touch compared to the common electrode not adjacent to the second display device. The integrated value of the current without touch increases, and even if there is no touch at the positions of the plurality of common electrodes adjacent to the second display device, it may be erroneously detected as having touch. Similarly, the positions of a plurality of common electrodes adjacent to the first display device in the second display device may be erroneously detected as having a touch.

In contrast to this comparative example, in the present embodiment, since the phase of the first touch drive signal TX1 and the phase of the second touch drive signal TX2 are aligned as described above, the common electrode of the adjacent first display device 22a is aligned. The potential difference between the 34 and the common electrode 34 of the second display device 22b can be substantially eliminated. As a result, charging / discharging of the parasitic capacitance Cp between these common electrodes 34 can be suppressed, and the integrated value of the current when there is no touch in each of these common electrodes 34 is the current when there is no touch in the other common electrodes 34. Can be equal to the integral value of. Therefore, it is possible to suppress erroneous touch detection near the boundary between the first display device 22a and the second display device 22b.

Note that "the phase of the first touch drive signal TX1 and the phase of the second touch drive signal TX2 are aligned" means that there may be a small phase difference such that touch is not erroneously detected. This phase difference is smaller than the phase difference corresponding to the period during which the current ICp is flowing. For example, when the first touch drive signal TX1 rises and a positive current ICp flows, and then the second touch drive signal TX2 rises and a negative current ICp flows while the current ICp decreases, the negative current ICp The integrated value is smaller than the comparative example. Even in this case, erroneous touch detection can be suppressed with respect to the comparative example.

(Second Embodiment)
In the first embodiment, the drive capabilities of the first drive circuit 74a and the second drive circuit 74b may differ due to variations in electrical characteristics and temperature differences between the first drive circuit 74a and the second drive circuit 74b. Similarly, the drive capabilities of the elements constituting the first clock generation circuit 78a and the second clock generation circuit 78b may be different. In this case, the phase difference between the first reference clock signal CK1 and the second reference clock signal CK2 and the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2 become large, and the first display device 22a and the second display device 22a and the second display device 22a and the second. Touches are likely to be erroneously detected near the boundary of the display device 22b. In particular, in the in-vehicle display system 1, there is a possibility that the temperature difference between the two display modules 20 becomes large due to the temperature difference in the configuration of the vehicle on the rear side of the two display modules 20.

Therefore, in the second embodiment, the phase difference is controlled by acquiring the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2, which is different from the first embodiment. Hereinafter, the differences from the first embodiment will be mainly described.

FIG. 11 is a block diagram of the display system 1 according to the second embodiment. The second display control device 24b supplies the timing signal ST to the first display control device 24a. The timing signal ST is, for example, the second touch drive signal TX2. The timing signal ST is not particularly limited as long as it is a signal capable of specifying the rise timing of the second touch drive signal TX2, and may be a pulse indicating the rise timing of the second touch drive signal TX2, or the start of the touch detection period. It may be a pulse indicating timing. The pulse indicating the start timing of the touch detection period can be generated based on the horizontal synchronization signal, and indicates that the second touch drive signal TX2 rises after a predetermined waiting time from the rising timing of this pulse.

The first control circuit 70a has an acquisition unit 90 and a control unit 92. The acquisition unit 90 has a first touch drive signal TX1 and a second touch drive based on the timing signal ST supplied from the second display control device 24b and the first touch drive signal TX1 generated by the first drive circuit 74a. Acquires the phase difference of the signal TX2.

The control unit 92 controls the phase of the first touch drive signal TX1 so that the phase difference acquired by the acquisition unit 90 approaches zero. For example, the control unit 92 controls the first drive circuit 74a to provide a phase difference between the first reference clock signal CK1 and the first touch drive signal TX1.

The control unit 92 may control the phase of the second touch drive signal TX2 instead of the phase of the first touch drive signal TX1. In this case, the control unit 92 may control the first clock generation circuit 78a to provide a phase difference between the first reference clock signal CK1 and the synchronization signal SY. Based on the phase-controlled synchronization signal SY, the second drive circuit 74b generates the second touch drive signal TX2 whose phase difference with respect to the first touch drive signal TX1 approaches zero. Alternatively, the control unit 92 supplies data indicating the phase difference to the second display control device 24b, and based on the data indicating the phase difference, the second drive circuit 74b has zero phase difference with respect to the first touch drive signal TX1. The second touch drive signal TX2 approaching to may be generated. The acquisition unit 90 and the control unit 92 periodically execute the above-mentioned processing at a predetermined frequency.

FIG. 12 shows an example of the waveforms of the timing signal ST and the first touch drive signal TX1 of the display system 1 of FIG. Although there is a phase difference at time t1 such as immediately after the display system 1 is started, the phase difference is corrected to almost zero at time t2.

According to the present embodiment, there is a case where a phase difference occurs between the first touch drive signal TX1 and the second touch drive signal TX2 due to a difference in electrical characteristics between the first drive circuit 74a and the second drive circuit 74b. However, the phase difference can be made smaller. Therefore, even in such a case, erroneous detection near the boundary between the first display device 22a and the second display device 22b can be suppressed. Since there may be a temperature difference on the back side of the two display modules 20, restrictions on the arrangement position of the display modules 20 can be reduced.

In the above description, it is assumed that the wiring delay of the timing signal ST is small enough not to substantially affect the phase difference, but when the wiring delay of the timing signal ST is relatively large, it is preliminarily based on the wiring length. The delay time may be calculated and the acquisition unit 90 may hold the delay time. The acquisition unit 90 corrects the phase of the timing signal ST supplied from the second display control device 24b with the delay time, and acquires the phase difference excluding the wiring delay. In this case, there is a wiring delay of the synchronization signal SY, but since the phase of the timing signal ST also includes the wiring delay of the synchronization signal SY, the influence of the wiring delay of the synchronization signal SY can be corrected.

(Third Embodiment)
Similarly to the second embodiment, the third embodiment also deals with the situation where the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2 becomes large. In the third embodiment, increasing the integration period of the touch detection signal RX is different from the first embodiment. Hereinafter, the differences from the first embodiment will be mainly described.

FIG. 13 is a block diagram of the display system 1 according to the third embodiment. The second display control device 24b supplies the timing signal ST to the first display control device 24a as in the second embodiment.

The first control circuit 70a includes an acquisition unit 90 and a first setting unit 96a. The acquisition unit 90 acquires the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2 as in the second embodiment. The phase difference also indicates which phase of the first touch drive signal TX1 or the second touch drive signal TX2 is advanced. The acquisition unit 90 notifies the second display control device 24b of the phase difference by the phase difference data PD.

The first setting unit 96a sets the first period and the third period, which are integration periods, based on the phase difference acquired by the acquisition unit 90, and detects the first touch based on the set first period and third period. It controls the circuit 76a.

The first setting unit 96a derives the integration time obtained by adding the reference time to the time corresponding to the phase difference. The reference time is the time for the touch detection circuit 76 to perform one integration in the first embodiment. The reference time is a predetermined time longer than the time from the rising timing of the first touch drive signal TX1 to the timing when the charging current flowing through the parasitic capacitance with respect to the ground potential of the common electrode 34 becomes zero. The predetermined time can be appropriately set by experiments or simulations so that the desired touch detection performance can be obtained.

When the phase of the first touch drive signal TX1 is advanced, the first setting unit 96a sets the first period from the rising timing of the first touch drive signal TX1 to the timing when the integration time has elapsed, and sets the first touch drive. A third period is set from the falling timing of the signal TX1 to the timing when the integration time has elapsed.

When the phase of the second touch drive signal TX2 is advanced, the first setting unit 96a is from a timing earlier than the rising timing of the first touch drive signal TX1 by a time corresponding to the phase difference to the timing when the integration time has elapsed. The first period is set, and the third period is set from the timing corresponding to the phase difference earlier than the falling timing of the first touch drive signal TX1 to the timing when the integration time has elapsed.

The first touch detection circuit 76a integrates the touch detection signal RX and acquires the integrated value during the first period, and integrates the touch detection signal RX and acquires the integrated value during the third period. Repeat the process. The first touch detection circuit 76a may integrate in either the first period or the third period.

The second control circuit 70b has a second setting unit 96b. The second setting unit 96b sets the second period and the fourth period, which are integration periods, based on the phase difference notified from the acquisition unit 90, and detects the second touch based on the set second period and fourth period. Controls circuit 76b.

The second setting unit 96b derives the integration time obtained by adding the reference time to the time corresponding to the phase difference. Since this integration time is equal to the integration time derived by the first setting unit 96a, it may be notified from the first setting unit 96a.

When the phase of the first touch drive signal TX1 is advanced, the second setting unit 96b is from a timing earlier than the rising timing of the second touch drive signal TX2 by a time corresponding to the phase difference to the timing when the integration time has elapsed. The second period is set, and the fourth period is set from the timing corresponding to the phase difference earlier than the falling timing of the second touch drive signal TX2 to the timing when the integration time has elapsed.

When the phase of the second touch drive signal TX2 is advanced, the second setting unit 96b sets the second period from the rising timing of the second touch drive signal TX2 to the timing when the integration time has elapsed, and sets the second touch drive. The fourth period from the falling timing of the signal TX2 to the timing when the integration time has elapsed is set.

The second touch detection circuit 76b integrates the touch detection signal RX and acquires the integrated value during the second period, and integrates the touch detection signal RX and acquires the integrated value during the fourth period. Repeat the process. The second touch detection circuit 76b may integrate in either the second period or the fourth period.

The acquisition unit 90, the first setting unit 96a, and the second setting unit 96b periodically execute the above-mentioned processing at a predetermined frequency. As a result, even if the phase difference changes due to a temperature change or the like, the integration period can be set according to the phase difference. Since the integration period can be prevented from becoming longer than necessary, fluctuations in the integrated value due to external noise can be suppressed.

FIG. 14 shows an example of the waveforms of the first touch drive signal TX1, the second touch drive signal TX2, and the current ICp according to the third embodiment. A phase difference is generated between the first touch drive signal TX1 and the second touch drive signal TX2 due to the difference in electrical characteristics between the first drive circuit 74a and the second drive circuit 74b, wiring delay, and the like. In this example, the first touch drive signal TX1 is ahead of the second touch drive signal TX2 in phase.

Each of the first touch drive signal TX1 and the second touch drive signal TX2 changes between the first voltage V1 and the second voltage V2. Here, the first voltage V1 is at a low level and the second voltage V2 is at a higher level than the first voltage V1, but vice versa.

The first period TC1 is a period from the rising timing A1 of the first touch drive signal TX1 to the timing A2 when the integration time has elapsed. The length of the first period TC1 is the sum of the time TP corresponding to the phase difference and the reference time TCx. That is, it can be said that the integration period of the first embodiment is extended backward by the time TP corresponding to the phase difference. The minimum first period TC1 is from the timing A1 until the reference time TCx elapses, and the maximum first period TC1 is from the timing A1 to immediately before the timing A3.

The third period TC3 is a period from the fall timing A3 of the first touch drive signal TX1 to the timing A4 when the integration time has elapsed. The length of the third period TC3 is also the sum of the time TP corresponding to the phase difference and the reference time TCx. The minimum third period TC3 is from the timing A3 to the elapse of the reference time TCx, and the maximum third period TC3 is from the timing A3 to immediately before the timing A7. The first period TC1 and the third period TC3 do not overlap.

The second period TC2 is a period from the timing A1 which is earlier than the rising timing A5 of the second touch drive signal TX2 by the time TP corresponding to the phase difference to the timing A2 when the integration time has elapsed. That is, it can be said that the integration period of the first embodiment is extended forward by the time TP corresponding to the phase difference. The minimum second period TC2 is from timing A5 to timing A2, and the maximum second period TC2 is from immediately after the end timing (not shown) of the immediately preceding fourth period TC4 to timing A2. In this example, the first period TC1 and the second period TC2 are equal.

The fourth period TC4 is a period from the timing A3, which is earlier than the fall timing A6 of the second touch drive signal TX2 by the time TP corresponding to the phase difference, to the timing A4 when the integration time has elapsed. The minimum fourth period TC4 is from timing A6 to timing A4, and the maximum fourth period TC4 is from immediately after timing A2 to timing A4. In this example, the third period TC3 and the fourth period TC4 are equal. The second period TC2 and the fourth period TC4 do not overlap.

Each of the first period TC1 and the second period TC2 includes a period from the first timing A1 to the second timing A10. Each of the third period TC3 and the fourth period TC4 includes a period from the third timing A3 to the fourth timing A11. If these conditions are satisfied, the first period TC1 and the second period TC2 may be different, and the third period TC3 and the fourth period TC4 may be different.

The first timing A1 is a timing at which one of the first touch drive signal TX1 and the second touch drive signal TX2 whose phase is advanced changes from the first voltage V1 to the second voltage V2.

In the second timing A10, of the first touch drive signal TX1 and the second touch drive signal TX2, the one whose phase is delayed changes from the first voltage V1 to the second voltage V2, so that the adjacent first display device 22a This is the timing at which the current ICp flowing between the common electrode 34 and the common electrode 34 of the second display device 22b becomes zero. The time from the timing A5 to the second timing A10 is called the current convergence time of the current ICp.

The third timing A3 is a timing at which the one of the first touch drive signal TX1 and the second touch drive signal TX2 whose phase is advanced changes from the second voltage V2 to the first voltage V1.

In the fourth timing A11, of the first touch drive signal TX1 and the second touch drive signal TX2, the one whose phase is delayed changes from the second voltage V2 to the first voltage V1 so that the adjacent first display device 22a This is the timing at which the current ICp flowing between the common electrode 34 and the common electrode 34 of the second display device 22b becomes zero.

Both charging and discharging for the parasitic capacitance Cp between the common electrode 34 of the adjacent first display device 22a and the common electrode 34 of the second display device 22b are the first period TC1, the second period TC2, the third period TC3, The fourth period is performed in each of TC4. Thereby, in the integrated value, the effects of charging and discharging on the parasitic capacitance Cp can be offset. This is because the charge amount and the discharge amount with respect to the parasitic capacitance Cp are almost equal. Therefore, even if there is a phase difference, erroneous touch detection can be suppressed near the boundary between the first display device 22a and the second display device 22b.

Of the first touch drive signal TX1 and the second touch drive signal TX2, the timing A5 in which the phase is delayed changes from the first voltage V1 to the second voltage V2, and the second timing A10 is the first timing A1. Of the first touch drive signal TX1 and the second touch drive signal TX2, the one whose phase is advanced is located between the timing A3 at which the second voltage V2 changes to the first voltage V1.

Of the first touch drive signal TX1 and the second touch drive signal TX2, the timing A6 in which the phase is delayed changes from the second voltage V2 to the first voltage V1, and the fourth timing A11 is the third timing A3. Of the first touch drive signal TX1 and the second touch drive signal TX2, the one whose phase is advanced is located between the timing A7 where the first voltage V1 changes to the second voltage V2.

Therefore, of the first touch drive signal TX1 and the second touch drive signal TX2, the one whose phase is advanced changes from the second voltage V2 to the first voltage V1, so that the current ICp flowing through the parasitic capacitance Cp is the first period. It does not affect the integrated values of TC1 and TC2 in the second period. Further, of the first touch drive signal TX1 and the second touch drive signal TX2, the one whose phase is advanced changes from the first voltage V1 to the second voltage V2, so that the current ICp flowing through the parasitic capacitance Cp is in the third period. It does not affect the integrated values of TC3 and TC4 in the 4th period. Therefore, in the integrated value, the effects of charging and discharging on the parasitic capacitance Cp can be more reliably offset.

Next, the overall operation of the display system 1 with the above configuration will be described. FIG. 15 is a flowchart showing the activation process of the display system 1 of FIG. The host 10 activates the first display control device 24a and the second display control device 24b (S10), and the first display control device 24a transmits a synchronization signal SY to the second display control device 24b (S12). The second display control device 24b drives the second display device 22b with the second touch drive signal TX2 synchronized with the received synchronization signal SY, and supplies the second touch drive signal TX2 to the first display control device 24a (S14). ). The first display control device 24a derives the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2, and notifies the second display control device 24b of the phase difference (S16). Each of the display control devices 24 sets the integration period based on the phase difference (S18), and ends the process.

According to the present embodiment, even when a phase difference occurs between the first touch drive signal TX1 and the second touch drive signal TX2, the touch is performed near the boundary between the first display device 22a and the second display device 22b. False detection can be suppressed. Further, since the integration period may be changed in the first embodiment, the design is easy.

(First variant example of the third embodiment)
In the first modification, the first period TC1 and the second period TC2 are different, and the third period TC3 and the fourth period TC4 are different. When the phase of the first touch drive signal TX1 is advanced, the operation of the second setting unit 96b is as described above, but if the sum of the time TP corresponding to the phase difference and the current convergence time is equal to or greater than the reference time TCx, the second setting unit 96b operates. The 1 setting unit 96a derives the integration time obtained by adding the current convergence time of the current ICp to the time TP corresponding to the phase difference. When the phase difference is small and the sum of the time TP corresponding to the phase difference and the current convergence time is shorter than the reference time TCx, the first setting unit 96a sets the reference time TCx as the integration time. Since the current convergence time is shorter than the reference time TCx, when the sum of the time TP corresponding to the phase difference and the current convergence time is longer than the reference time TCx, the first period TC1 is shorter than the second period TC2 and the third period TC3 is the third. It will be shorter than TC4 for 4 periods. In this case, since the integration period in the first touch detection circuit 76a can be shortened, fluctuations in the integrated value due to external noise can be suppressed.

Similarly, when the phase of the second touch drive signal TX2 is advanced, the operation of the first setting unit 96a is as described above, but the sum of the time TP corresponding to the phase difference and the current convergence time is equal to or more than the reference time TCx. For example, the second setting unit 96b derives the integration time obtained by adding the current convergence time to the time TP corresponding to the phase difference. When the sum of the time TP corresponding to the phase difference and the current convergence time is shorter than the reference time TCx, the reference time TCx is set as the integration time. When the sum of the time TP corresponding to the phase difference and the current convergence time is longer than the reference time TCx, the second period TC2 is shorter than the first period TC1 and the fourth period TC4 is shorter than the third period TC3. In this case, since the integration period in the second touch detection circuit 76b can be shortened, fluctuations in the integrated value due to external noise can be suppressed.

(Second variant of the third embodiment)
Only in the first touch detection period T4a in which the first touch detection circuit 76a detects a touch in the first touch detection area R1a adjacent to the second display device 22b, the first setting unit 96a sets the first period based on the phase difference. TC1 and the third period TC3 may be set. In the other first touch detection periods T1a to T3a, the first setting unit 96a sets the first period TC1 from the rising timing A1 of the first touch drive signal TX1 to the timing when the reference time TCx has elapsed, and the first touch. The third period TC3 from the fall timing A3 of the drive signal TX1 to the timing at which the reference time TCx has elapsed may be set. That is, in the first touch detection periods T1a to T3a, the integration is performed for the same period as in the first embodiment.

Similarly, only in the second touch detection period T1b in which the second touch detection circuit 76b detects a touch in the second touch detection area R1b adjacent to the first display device 22a, the second setting unit 96b is based on the phase difference. The second period TC2 and the fourth period TC4 may be set. In the other second touch detection periods T2b to T4b, the second setting unit 96b sets the second period TC2 from the rising timing A5 of the second touch drive signal TX2 to the timing A2 when the reference time TCx has elapsed, and the second The fourth period TC4 from the fall timing A6 of the touch drive signal TX2 to the timing A4 where the reference time TCx has elapsed may be set. That is, in the second touch detection period T2b to T4b, the same integration processing as in the first embodiment is performed.

In this modification, since the integration period can be shortened except for the touch detection region adjacent to the adjacent display device 22, fluctuation of the integrated value due to external noise can be suppressed.

(Third variant example of the third embodiment)
When the maximum value of the phase difference due to a temperature change or the like can be obtained in advance by an experiment or a simulation, the first setting unit 96a may set the first period TC1 and the third period TC3 based on the maximum value of the phase difference. The same applies to the second setting unit 96b. The first period TC1 to the fourth period TC4 are fixed values. In this modification, it is not necessary to periodically acquire the phase difference and set the first period TC1 and the like, so that the processing can be simplified. The wiring that transmits the timing signal ST and the phase difference data PD can also be eliminated.

Further, when the maximum value of the phase difference is unknown, each of the first period TC1 to the fourth period TC4 may be set to the maximum in advance if the touch drive signal in which the phase is advanced is known. In this case, the design is easy.

(Fourth Embodiment)
In the fourth embodiment, the control device 12 of the host 10 transmits the synchronization signal SY to the first display device 22a and the second display device 22b, which is different from the first embodiment. Hereinafter, the differences from the first embodiment will be mainly described.

FIG. 16 is a block diagram of the display system 1 according to the fourth embodiment. The control device 12 transmits, for example, a common synchronization signal SY to the first display control device 24a and the second display control device 24b at each start timing of the first frame period. The first display control device 24a does not transmit a synchronization signal to the second display control device 24b.

The first clock generation circuit 78a generates the first reference clock signal CK1 synchronized with the synchronization signal SY based on the synchronization signal SY supplied from the control device 12. The second clock generation circuit 78b generates the second reference clock signal CK2 synchronized with the synchronization signal SY based on the synchronization signal SY supplied from the control device 12. Even in this way, the first touch drive signal TX1 and the second touch drive signal TX2 having the same phase can be generated.
According to this embodiment, the degree of freedom in the configuration of the display system 1 can be improved.

(First variant example of the fourth embodiment)
The second embodiment may be combined with the fourth embodiment. In this case, the first display control device 24a supplies the first timing signal to the control device 12. The second display control device 24b supplies the second timing signal to the control device 12. Instead of the first control circuit 70a, the control device 12 has an acquisition unit 90 and a control unit 92.

The acquisition unit 90 acquires the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2 based on the supplied first timing signal and second timing signal.

The control unit 92 controls the phase of the first touch drive signal TX1 so that the phase difference acquired by the acquisition unit 90 approaches zero. For example, the control unit 92 supplies the phase difference to the first display control device 24a, and based on the phase difference, the first drive circuit 74a outputs the first touch drive signal TX1 whose phase is aligned with the second touch drive signal TX2. Generate. The control unit 92 may control the phase of the second touch drive signal TX2.

Alternatively, the control unit 92 generates a first synchronization signal and a second synchronization signal having the acquired phase difference, supplies the first synchronization signal to the first display control device 24a, and supplies the second synchronization signal. May be supplied to the second display control device 24b.
This modification has the effects of each of the second and fourth embodiments.

(Second variant example of the fourth embodiment)
The third embodiment may be combined with the fourth embodiment. In this case, the first display control device 24a supplies the first timing signal to the control device 12. The second display control device 24b supplies the second timing signal to the control device 12. The control device 12 has an acquisition unit 90 instead of the first control circuit 70a.

The acquisition unit 90 acquires the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2 based on the supplied first timing signal and second timing signal, and controls the acquired phase difference for the first display. It is supplied to the device 24a and the second display control device 24b. In the first setting unit 96a and the second setting unit 96b, the same processing as in the third embodiment is executed.

FIG. 17 is a flowchart showing a start-up process of the display system 1 according to the second modified example of the fourth embodiment. The host 10 activates the first display control device 24a and the second display control device 24b (S30), and transmits a synchronization signal SY to the first display control device 24a and the second display control device 24b (S32). Each of the display control devices 24 drives the display device 22 with a touch drive signal synchronized with the received synchronization signal SY, and supplies the touch drive signal to the host 10 (S34). The host 10 derives the phase difference between the first touch drive signal TX1 and the second touch drive signal TX2, and notifies the respective display control devices 24 of the phase difference (S36). The display control device 24 sets the integration period based on the notified phase difference (S38), and ends the process.
This modification has the effects of each of the third and fourth embodiments.

(Fifth Embodiment)
In the fifth embodiment, a method of changing the frequency of the touch drive signal TX in order to make it less susceptible to the influence of external noise will be described. Hereinafter, the points that overlap with the contents described in the first embodiment will be omitted.

If the frequency of the external noise radiated from the electronic devices around the display system 1 is equal to the frequency of the touch drive signal TX, the accuracy and sensitivity of the touch detection may decrease. Therefore, the display system 1 controls to change the frequency of the touch drive signal TX according to the amount of external noise (so-called frequency hopping control). Well-known techniques can be used for frequency hopping.

The first control circuit 70a of the first display control device 24a controls the first drive circuit 74a so as to change the frequency of the first touch drive signal TX1. Then, the first control circuit 70a outputs a frequency change instruction including the frequency information of the change destination first touch drive signal TX1 to the second control circuit 70b of the second display control device 24b.
The second control circuit 70b controls the second drive circuit 74b so as to change the frequency of the second touch drive signal TX2 based on the frequency change instruction acquired from the first control circuit 70a. Specifically, the second control circuit 70b causes the second drive circuit 74b to change the frequency of the second touch drive signal TX2 to the same frequency as the frequency of the change destination first touch drive signal TX1.

The second control circuit 70b of the second display control device 24b controls the second drive circuit 74b so as to change the frequency of the second touch drive signal TX2. Then, a frequency change instruction including frequency information of the change destination second touch drive signal TX2 is output to the first control circuit 70a of the first display control device 24a.
The first control circuit 70a controls the first drive circuit 74a so as to change the frequency of the first touch drive signal TX1 based on the frequency change instruction acquired from the second control circuit 70b. Specifically, the first control circuit 70a changes the frequency of the first touch drive signal TX1 to the same frequency as the frequency of the change destination second touch drive signal TX2 with respect to the first control circuit 70a.

(First modification of the fifth embodiment)
The first control circuit 70a and the second control circuit 70b may each transmit frequency change instructions to each other via the host 10.

The first control circuit 70a transmits a frequency change instruction including frequency information of the first touch drive signal TX1 to be changed to the host 10. The host 10 transmits the frequency change instruction acquired from the first control circuit 70a to the second control circuit 70b. The second control circuit 70b controls the second drive circuit 74b so as to change the frequency of the second touch drive signal TX2 based on the frequency change instruction acquired from the host 10.

The second control circuit 70b transmits a frequency change instruction including frequency information of the second touch drive signal TX2 to be changed to the host 10. The host 10 transmits the frequency change instruction acquired from the second control circuit 70b to the first control circuit 70a. The first control circuit 70a controls the first drive circuit 74a so as to change the frequency of the first touch drive signal TX1 based on the frequency change instruction acquired from the host 10.

(Second variant of the fifth embodiment)
The host 10 may generate a frequency change instruction and transmit it to each of the first control circuit 70a and the second control circuit 70b.

(Sixth Embodiment)
In the sixth embodiment, synchronization control when the start timings of the first display module 20a and the second display module 20b are different will be described. Hereinafter, the points that overlap with the contents described in the first embodiment will be omitted.

FIG. 18 is a flowchart showing an output process of the synchronization signal SY in the first display control device 24a. The first display control device 24a outputs the synchronization signal SY to the second display control device 24b (S52) in the activated state of the second display module 20b (S50: YES). On the other hand, if the second display module 20b is not in the activated state (S50: NO), the first display control device 24a repeats the determination process in step S50. The first display control device 24a may acquire information regarding the activation state of the second display module 20b from the second display module 20b or from the host 10.

The second display control device 24b has a configuration having a function of generating a synchronization signal SY in the second clock generation circuit 78b, similarly to the first display control device 24a, and the second display control device 24b is shown in FIG. The processing may be performed.

(7th Embodiment)
In a seventh embodiment, the display system 1 includes a host 10a and a host 10b, and the host 10a and the host 10b control each of the first display module 20a and the second display module 20b, respectively. Different from the embodiment. Hereinafter, the differences from the fourth embodiment will be mainly described.

FIG. 19 is a block diagram of the display system 100 according to the seventh embodiment. The display system 100 includes a host 10a, a host 10b, a first display module 20a, and a second display module 20b.

The host 10a includes a control device 12a and controls the first display module 20a. The host 10a is arranged on a substrate different from the first display module 20a, for example.
The host 10b includes a control device 12b and controls the second display module 20b. The host 10b is arranged on a substrate different from the second display module 20b, for example.

The control device 12a is, for example, a CPU, and is also called a host CPU. The control device 12a supplies the image data DD and the control data CD to the first display module 20a, and controls the first display module 20a based on these data.
The control device 12b is, for example, a CPU, and is also called a host CPU. The control device 12b supplies the image data DD and the control data CD to the second display module 20b, and controls the second display module 20b based on these data.

The control device 12a transmits a synchronization signal SY to the first display control device 24a, for example, at each start timing of the first frame period. The control device 12a further transmits a synchronization signal SY to the control device 12b at a predetermined timing. The control device 12b transmits the received synchronization signal SY to the second display control device 24b.

The first clock generation circuit 78a generates the first reference clock signal CK1 synchronized with the synchronization signal SY based on the synchronization signal SY supplied from the control device 12a. The second clock generation circuit 78b generates the second reference clock signal CK2 synchronized with the synchronization signal SY based on the synchronization signal SY supplied from the control device 12b. According to this embodiment, the degree of freedom in the configuration of the display system 100 can be improved.

The display system 1 of the first to third embodiments includes a host 10a and a host 10b like the display system 100 of the seventh embodiment, and each of the host 10a and the host 10b is a first display module. 20a and the second display module 20b may be controlled respectively.

The display system 1 of the fifth embodiment includes the host 10a and the host 10b as in the display system 100 of the seventh embodiment, and the host 10a and the host 10b have the first display module 20a and the first display module 20a and the host 10b, respectively. 2 Each of the display modules 20b may be controlled. Then, one of the host 10a and the host 10b transmits a frequency change instruction of the touch drive signal TX to the other, and the host 10a and the host 10b send the frequency change instruction to the first display control device 24a and the second, respectively. It may be transmitted to the display control device 24b respectively.

The display system 1 of the sixth embodiment includes the host 10a and the host 10b as in the display system 100 of the seventh embodiment, and the host 10a and the host 10b have the first display module 20a and the first display module 20a and the host 10b, respectively. 2 Each of the display modules 20b may be controlled. Then, the host 10a may transmit the information regarding the activation state of the first display module 20a to the host 10b, and the host 10b may transmit the information to the second display module 20b. The host 10b may transmit information regarding the activation state of the second display module 20b to the host 10a, and the host 10a may transmit the information to the first display module 20a.

The present invention has been described above based on the embodiments. This embodiment is an example, and it will be understood by those skilled in the art that various modifications are possible for each of these components or combinations of each processing process, and that such modifications are also within the scope of the present invention. By the way.

For example, in the first to third embodiments, the synchronization signal SY output from the first display control device 24a is input to the control device 12 of the host 10, and the buffer circuit (not shown) of the control device 12 is input. The sync signal SY may be buffered and the buffered sync signal SY may be supplied to the second display control device 24b. In this modification, the amplitude of the synchronization signal SY can be maintained even when the wiring of the synchronization signal SY is relatively long.

Further, three or more display devices 22 may be arranged adjacent to each other. In the embodiment, the display control device 24 is included in the display module 20, but the display control device 24 may be included in the host 10. The frame period may include a touch detection period that is twice or more the number of touch detection areas of the display device 22. In these modified examples, the degree of freedom in the configuration of the display system 1 can be improved.

Although the in-cell type display device 22 has been described, the display device 22 may be an out-cell type. In this case, the display device 22 includes a sensor electrode dedicated to touch detection, and detects the touch by a self-capacitating method using the sensor electrode in parallel with the image display. Even in the case of the out-cell type display device 22, erroneous detection of touch near the boundary between the two display devices 22 can be suppressed.

The display system according to one aspect of the present disclosure is
A first display device having a plurality of first sensor electrodes,
A second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes, and a second display device.
A first drive circuit that supplies a first touch drive signal to the plurality of first sensor electrodes,
With the second drive circuit that supplies the second touch drive signal having the same frequency as the frequency of the first touch drive signal and having the same phase as the first touch drive signal to the plurality of second sensor electrodes. ,
A first touch detection circuit that detects the touch of an object on the first display device based on touch detection signals received from each of the plurality of first sensor electrodes.
A second touch detection circuit that detects the touch of an object on the second display device based on the touch detection signals received from each of the plurality of second sensor electrodes.
To be equipped.
According to this aspect, erroneous detection of touch near the boundary between the first display device and the second display device can be suppressed.

In the display system according to one aspect of the present disclosure, for example,
A first clock generation circuit that generates a first reference clock signal and a synchronization signal synchronized with the first reference clock signal.
A second clock generation circuit that generates a second reference clock signal synchronized with the synchronization signal generated by the first clock generation circuit, and a second clock generation circuit.
With
The first drive circuit generates the first touch drive signal synchronized with the first reference clock signal.
The second drive circuit may generate the second touch drive signal synchronized with the second reference clock signal.
In this case, the phases of the first touch drive signal and the second touch drive signal can be aligned.

In the display system according to one aspect of the present disclosure, for example,
A control device that outputs a synchronization signal and
A first clock generation circuit that generates a first reference clock signal synchronized with the synchronization signal output from the control device, and a first clock generation circuit.
A second clock generation circuit that generates a second reference clock signal synchronized with the synchronization signal output from the control device, and a second clock generation circuit.
With
The first drive circuit generates the first touch drive signal synchronized with the first reference clock signal.
The second drive circuit may generate the second touch drive signal synchronized with the second reference clock signal.
In this case, the phases of the first touch drive signal and the second touch drive signal can be aligned.

In the display system according to one aspect of the present disclosure, for example,
An acquisition unit that acquires the phase difference between the first touch drive signal and the second touch drive signal, and
A control unit that controls the phase of the first touch drive signal or the second touch drive signal so that the phase difference acquired by the acquisition unit approaches zero.
May be provided.
In this case, even when a phase difference occurs between the first touch drive signal and the second touch drive signal due to a difference in electrical characteristics between the first drive circuit and the second drive circuit, the phase difference can be made smaller. Therefore, erroneous detection near the boundary between the first display device and the second display device can be suppressed.

In the display system according to one aspect of the present disclosure, for example,
Each of the first touch drive signal and the second touch drive signal changes between the first voltage and the second voltage.
The first touch detection circuit integrates the touch detection signals received from each of the plurality of first sensor electrodes during the first period, and detects the touch of an object on the first display device based on the integrated value. ,
The second touch detection circuit integrates the touch detection signals received from each of the plurality of second sensor electrodes during the second period, and detects the touch of an object on the second display device based on the integrated value. ,
In each of the first period and the second period, the first timing in which the one in which the phase of the first touch drive signal and the second touch drive signal is advanced changes from the first voltage to the second voltage. Including the period from to the second timing
The second timing is such that the phase of the first touch drive signal and the second touch drive signal whose phase is delayed changes from the first voltage to the second voltage, so that the adjacent first display device has the second timing. It may be the timing when the current flowing between the first sensor electrode and the second sensor electrode of the second display device becomes zero.
In this case, even if a phase difference occurs between the first touch drive signal and the second touch drive signal due to a difference in characteristics between the first drive circuit and the second drive circuit, the first display device and the second display device False positives can be suppressed near the boundary of.

In the display system according to one aspect of the present disclosure, for example,
An acquisition unit that acquires the phase difference between the first touch drive signal and the second touch drive signal, and
A first setting unit that sets the first period based on the phase difference acquired by the acquisition unit, and
A second setting unit that sets the second period based on the phase difference acquired by the acquisition unit, and
May be provided.
In this case, the first period and the second period can be set according to the phase difference.

In the display system according to one aspect of the present disclosure, for example,
Of the first touch drive signal and the second touch drive signal, the timing in which the phase is delayed changes from the first voltage to the second voltage, and the second timing is the first timing and the above. Of the first touch drive signal and the second touch drive signal, the one whose phase is advanced may be located between the timing of changing from the second voltage to the first voltage.
In this case, of the first touch drive signal and the second touch drive signal, the one whose phase is advanced changes from the second voltage to the first voltage, so that the common electrode of the adjacent first display device and the second display device The current flowing through the parasitic capacitance between the common electrode and the common electrode does not affect the integrated value. Therefore, in the integrated value, the effects of charging and discharging on this parasitic capacitance can be more reliably offset.

The display system according to one aspect of the present disclosure is
A first display device having a plurality of first sensor electrodes,
A second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes, and a second display device.
A first drive circuit that supplies a first touch drive signal to the plurality of first sensor electrodes,
A second drive circuit that supplies a second touch drive signal having the same frequency as the frequency of the first touch drive signal to the plurality of second sensor electrodes.
A first touch detection circuit that integrates touch detection signals received from each of the plurality of first sensor electrodes during the first period and detects a touch of an object on the first display device based on the integrated value.
A second touch detection circuit that integrates the touch detection signals received from each of the plurality of second sensor electrodes during the second period and detects the touch of an object on the second display device based on the integrated value.
With
Each of the first touch drive signal and the second touch drive signal changes between the first voltage and the second voltage.
In each of the first period and the second period, the first timing in which the one in which the phase of the first touch drive signal and the second touch drive signal is advanced changes from the first voltage to the second voltage. Including the period from to the second timing
The second timing is such that the phase of the first touch drive signal and the second touch drive signal whose phase is delayed changes from the first voltage to the second voltage, so that the adjacent first display device has the second timing. This is the timing when the current flowing between the first sensor electrode and the second sensor electrode of the second display device becomes zero.
The timing at which the second touch drive signal changes from the first voltage to the second voltage, the second timing is the first timing, and the first touch drive signal is from the second voltage to the first voltage. It is located between the timing when it changes to.
According to this aspect, erroneous detection of touch near the boundary between the first display device and the second display device can be suppressed.

In the display system according to one aspect of the present disclosure, for example,
The first sensor electrode and the second sensor electrode are common electrodes shared for image display and touch detection.
In the first frame period of the first display device, the first display period in which the first display device displays an image and the first touch detection period in which the first touch detection circuit detects a touch are alternately arranged. ,
In the second frame period of the second display device, the second display period in which the second display device displays an image and the second touch detection period in which the second touch detection circuit detects a touch are alternately arranged. ,
In the first touch detection period and the second touch detection period, the start timing may be the same and the end timing may be the same.
In this case, it is possible to suppress erroneous touch detection near the boundary between the in-cell type first display device and the second display device.

The control device according to one aspect of the present disclosure is
A control device that controls a first display device having a plurality of first sensor electrodes and a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes.
A first drive circuit that supplies a first touch drive signal to the plurality of first sensor electrodes,
With the second drive circuit that supplies the second touch drive signal having the same frequency as the frequency of the first touch drive signal and having the same phase as the first touch drive signal to the plurality of second sensor electrodes. ,
A first touch detection circuit that detects the touch of an object on the first display device based on touch detection signals received from each of the plurality of first sensor electrodes.
A second touch detection circuit that detects the touch of an object on the second display device based on the touch detection signals received from each of the plurality of second sensor electrodes.
To be equipped.
According to this aspect, erroneous detection of touch near the boundary between the first display device and the second display device can be suppressed.

The control method according to one aspect of the present disclosure is
A control method for controlling a first display device having a plurality of first sensor electrodes and a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes.
A step of supplying the first touch drive signal to the plurality of first sensor electrodes, and
A step of supplying a second touch drive signal having the same frequency as the frequency of the first touch drive signal and having a phase aligned with that of the first touch drive signal to the plurality of second sensor electrodes.
A step of detecting a touch of an object on the first display device based on a touch detection signal received from each of the plurality of first sensor electrodes.
A step of detecting a touch of an object on the second display device based on a touch detection signal received from each of the plurality of second sensor electrodes.
To be equipped.
According to this aspect, erroneous detection of touch near the boundary between the first display device and the second display device can be suppressed.

1 ... Display system, 12, 12a, 12b ... Control device, 22 ... Display device, 22a ... First display device, 22b ... Second display device, 34 ... Common electrode, 74a ... First drive circuit, 74b ... Second drive Circuit, 76 ... touch detection circuit, 76a ... first touch detection circuit, 76b ... second touch detection circuit, 78a ... first clock generation circuit, 78b ... second clock generation circuit, 90 ... acquisition unit, 92 ... control unit, 96a ... 1st setting unit, 96b ... 2nd setting unit.

Claims (11)

A first display device having a plurality of first sensor electrodes,
A second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes, and a second display device.
A first drive circuit that supplies a first touch drive signal to the plurality of first sensor electrodes,
With the second drive circuit that supplies the second touch drive signal having the same frequency as the frequency of the first touch drive signal and having the same phase as the first touch drive signal to the plurality of second sensor electrodes. ,
A first touch detection circuit that detects the touch of an object on the first display device based on touch detection signals received from each of the plurality of first sensor electrodes.
A second touch detection circuit that detects the touch of an object on the second display device based on the touch detection signals received from each of the plurality of second sensor electrodes.
A display system characterized by being equipped with. A first clock generation circuit that generates a first reference clock signal and a synchronization signal synchronized with the first reference clock signal.
A second clock generation circuit that generates a second reference clock signal synchronized with the synchronization signal generated by the first clock generation circuit, and a second clock generation circuit.
With
The first drive circuit generates the first touch drive signal synchronized with the first reference clock signal.
The second drive circuit generates the second touch drive signal synchronized with the second reference clock signal.
The display system according to claim 1. A control device that outputs a synchronization signal and
A first clock generation circuit that generates a first reference clock signal synchronized with the synchronization signal output from the control device, and a first clock generation circuit.
A second clock generation circuit that generates a second reference clock signal synchronized with the synchronization signal output from the control device, and a second clock generation circuit.
With
The first drive circuit generates the first touch drive signal synchronized with the first reference clock signal.
The second drive circuit generates the second touch drive signal synchronized with the second reference clock signal.
The display system according to claim 1. An acquisition unit that acquires the phase difference between the first touch drive signal and the second touch drive signal, and
A control unit that controls the phase of the first touch drive signal or the second touch drive signal so that the phase difference acquired by the acquisition unit approaches zero.
The display system according to any one of claims 1 to 3, wherein the display system comprises. Each of the first touch drive signal and the second touch drive signal changes between the first voltage and the second voltage.
The first touch detection circuit integrates the touch detection signals received from each of the plurality of first sensor electrodes during the first period, and detects the touch of an object on the first display device based on the integrated value. ,
The second touch detection circuit integrates the touch detection signals received from each of the plurality of second sensor electrodes during the second period, and detects the touch of an object on the second display device based on the integrated value. ,
In each of the first period and the second period, the first timing in which the one in which the phase of the first touch drive signal and the second touch drive signal is advanced changes from the first voltage to the second voltage. Including the period from to the second timing
The second timing is such that the phase of the first touch drive signal and the second touch drive signal whose phase is delayed changes from the first voltage to the second voltage, so that the adjacent first display device has the second timing. This is the timing when the current flowing between the first sensor electrode and the second sensor electrode of the second display device becomes zero.
The display system according to any one of claims 1 to 3, wherein the display system is characterized in that. An acquisition unit that acquires the phase difference between the first touch drive signal and the second touch drive signal, and
A first setting unit that sets the first period based on the phase difference acquired by the acquisition unit, and
A second setting unit that sets the second period based on the phase difference acquired by the acquisition unit, and
The display system according to claim 5, wherein the display system comprises. Of the first touch drive signal and the second touch drive signal, the timing in which the phase is delayed changes from the first voltage to the second voltage, and the second timing is the first timing and the above. Of the first touch drive signal and the second touch drive signal, the one whose phase is advanced is located between the timing of changing from the second voltage to the first voltage.
The display system according to claim 5 or 6. A first display device having a plurality of first sensor electrodes,
A second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes, and a second display device.
A first drive circuit that supplies a first touch drive signal to the plurality of first sensor electrodes,
A second drive circuit that supplies a second touch drive signal having the same frequency as the frequency of the first touch drive signal to the plurality of second sensor electrodes.
A first touch detection circuit that integrates touch detection signals received from each of the plurality of first sensor electrodes during the first period and detects a touch of an object on the first display device based on the integrated value.
A second touch detection circuit that integrates the touch detection signals received from each of the plurality of second sensor electrodes during the second period and detects the touch of an object on the second display device based on the integrated value.
With
Each of the first touch drive signal and the second touch drive signal changes between the first voltage and the second voltage.
In each of the first period and the second period, the first timing in which the one in which the phase of the first touch drive signal and the second touch drive signal is advanced changes from the first voltage to the second voltage. Including the period from to the second timing
The second timing is such that the phase of the first touch drive signal and the second touch drive signal whose phase is delayed changes from the first voltage to the second voltage, so that the adjacent first display device has the second timing. This is the timing when the current flowing between the first sensor electrode and the second sensor electrode of the second display device becomes zero.
The timing at which the second touch drive signal changes from the first voltage to the second voltage, the second timing is the first timing, and the first touch drive signal is from the second voltage to the first voltage. Located between the timing of the change to,
A display system characterized by that. The first sensor electrode and the second sensor electrode are common electrodes shared for image display and touch detection.
In the first frame period of the first display device, the first display period in which the first display device displays an image and the first touch detection period in which the first touch detection circuit detects a touch are alternately arranged. ,
In the second frame period of the second display device, the second display period in which the second display device displays an image and the second touch detection period in which the second touch detection circuit detects a touch are alternately arranged. ,
In the first touch detection period and the second touch detection period, the start timing and the end timing match.
The display system according to any one of claims 1 to 7. A control device that controls a first display device having a plurality of first sensor electrodes and a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes.
A first drive circuit that supplies a first touch drive signal to the plurality of first sensor electrodes,
With the second drive circuit that supplies the second touch drive signal having the same frequency as the frequency of the first touch drive signal and having the same phase as the first touch drive signal to the plurality of second sensor electrodes. ,
A first touch detection circuit that detects the touch of an object on the first display device based on touch detection signals received from each of the plurality of first sensor electrodes.
A second touch detection circuit that detects the touch of an object on the second display device based on the touch detection signals received from each of the plurality of second sensor electrodes.
A control device comprising. A control method for controlling a first display device having a plurality of first sensor electrodes and a second display device arranged adjacent to the first display device and having a plurality of second sensor electrodes.
A step of supplying the first touch drive signal to the plurality of first sensor electrodes, and
A step of supplying a second touch drive signal having the same frequency as the frequency of the first touch drive signal and having a phase aligned with that of the first touch drive signal to the plurality of second sensor electrodes.
A step of detecting a touch of an object on the first display device based on a touch detection signal received from each of the plurality of first sensor electrodes.
A step of detecting a touch of an object on the second display device based on a touch detection signal received from each of the plurality of second sensor electrodes.
A control method characterized by comprising.

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