Patent ID: 12242148

DETAILED DESCRIPTION

The following describes embodiments in detail with reference to the drawings. The present invention is not limited to the embodiments described below. Components described below include a component that is easily conceivable by those skilled in the art and substantially the same component. The components described below can be appropriately combined. The disclosure is merely an example, and the present invention naturally encompasses an appropriate modification maintaining the gist of the invention that is easily conceivable by those skilled in the art. To further clarify the description, the width, the thickness, the shape, and the like of each component may be schematically illustrated in the drawings as compared with an actual aspect. However, the drawings merely provide examples, and are not intended to limit interpretation of the invention. The same element as that described in the drawing already discussed is denoted by the same reference numeral throughout the description and the drawings, and detailed description thereof will not be repeated in some cases.

First Embodiment

FIG.1is a block diagram illustrating a configuration example of a display device with a touch detection function according to a first embodiment. As illustrated inFIG.1, a display device1with a touch detection function includes a display unit10with a touch detection function, a control unit11, a gate driver12, a source driver13, a drive electrode driver14, and a touch detection unit40. In the display device1with a touch detection function, a touch detection function is incorporated in the display unit10with a touch detection function. The display unit10with a touch detection function is a device integrating a display panel20including a liquid crystal display element as a display element with a touch panel30serving as a touch detection device for detecting a touch input. The display unit10with a touch detection function may be what is called an on-cell device in which the touch panel30is mounted on the display panel20. The display panel20may be, for example, an organic EL display panel.

As described later, the display panel20is an element that sequentially performs scanning for each horizontal line to perform display in accordance with a scanning signal Vscan supplied from the gate driver12. The control unit11is a circuit that supplies a control signal to each of the gate driver12, the source driver13, the drive electrode driver14, and the touch detection unit40based on a video signal Vdisp supplied from the outside to control these components to operate in synchronization with each other.

The gate driver12has a function of sequentially selecting one horizontal line to be a display driving target of the display unit10with a touch detection function based on the control signal supplied from the control unit11.

The source driver13is a circuit that supplies a pixel signal Vpix to each sub-pixel SPix (described later) in the display unit10with a touch detection function based on the control signal supplied from the control unit11.

The drive electrode driver14is a circuit that supplies a drive signal Vcom to a drive electrode COML (described later) in the display unit10with a touch detection function based on the control signal supplied from the control unit11.

The touch panel30operates based on a basic principle of capacitance touch detection, and performs a touch detection operation using a mutual capacitance system to detect contact or proximity of an external conductor to a display region. The touch panel30may perform a touch detection operation using a self capacitance system.

The touch detection unit40is a circuit that detects whether there is a touch on the touch panel30based on the control signal supplied from the control unit11and a touch detection signal Vdet1supplied from the touch panel30. The touch detection unit40obtains coordinates at which a touch input is performed when there is a touch. The touch detection unit40includes a touch detection signal amplification unit42, an A/D conversion unit43, a signal processing unit44, and a coordinate extracting unit45. A detection timing control unit46controls the A/D conversion unit43, the signal processing unit44, and the coordinate extracting unit45to operate in synchronization with each other based on the control signal supplied from the control unit11.

As described above, the touch panel30operates based on the basic principle of capacitance touch detection. With reference toFIGS.2to6, the following describes the basic principle of mutual capacitance touch detection performed by the display device1with a touch detection function according to the present embodiment.FIG.2is an explanatory diagram representing a state in which a finger is in a non-contact state or a non-proximate state for explaining the basic principle of mutual capacitance touch detection.FIG.3is an explanatory diagram illustrating an example of an equivalent circuit of the state in which the finger is in a non-contact state or a non-proximate state as illustrated inFIG.2.FIG.4is an explanatory diagram representing a state in which the finger is in a contact state or a proximate state for explaining the basic principle of mutual capacitance touch detection.FIG.5is an explanatory diagram illustrating an example of an equivalent circuit of the state in which the finger is in a contact state or a proximate state as illustrated inFIG.4.FIG.6is a diagram representing an example of waveforms of the drive signal and the touch detection signal. The following describes a case in which the finger is brought into contact with or proximate to the touch panel. Alternatively, for example, an object including a conductor such as a stylus pen may be replaced with the finger.

For example, as illustrated inFIG.2, a capacitive element C1includes a pair of electrodes arranged to be opposed to each other with a dielectric D interposed therebetween, that is, a drive electrode E1and a touch detection electrode E2. As illustrated inFIG.3, one end of the capacitive element C1is coupled to an AC signal source (drive signal source) S, and the other end thereof is coupled to a voltage detector DET. The voltage detector DET is, for example, an integrating circuit included in the touch detection signal amplification unit42illustrated inFIG.1.

When an AC rectangular wave Sg having a predetermined frequency (for example, about several kHz to several hundreds kHz) is applied to the drive electrode E1(one end of the capacitive element C1) from the AC signal source S, an output waveform (touch detection signal Vdet1) as illustrated inFIG.6appears via the voltage detector DET coupled to the touch detection electrode E2(the other end of the capacitive element C1). The AC rectangular wave Sg corresponds to the drive signal Vcom input from the drive electrode driver14.

In a state in which the finger is not in contact with or proximate to the touch panel (non-contact state), as illustrated inFIGS.2and3, a current I0corresponding to a capacitance value of the capacitive element C1flows in accordance with charge and discharge of the capacitive element C1. The voltage detector DET illustrated inFIG.3converts variation in the current I0corresponding to the AC rectangular wave Sg into variation in a voltage (a waveform V0of a solid line (refer toFIG.6)).

In a state in which the finger is in contact with or proximate to the touch panel (contact state), as illustrated inFIG.4, capacitance C2generated by the finger is in contact with or proximate to the touch detection electrode E2, so that capacitance corresponding to a fringe between the drive electrode E1and the touch detection electrode E2is shielded. Due to this, as illustrated inFIG.5, the capacitive element C1functions as a capacitive element C1′ having a capacitance value smaller than the capacitance value in a non-contact state. With reference to the equivalent circuit illustrated inFIG.5, a current I1flows through the capacitive element C1′. As illustrated inFIG.6, the voltage detector DET converts variation in the current I1corresponding to the AC rectangular wave Sg into variation in the voltage (a waveform V1of a dotted line). In this case, amplitude of the waveform V1is smaller than that of the waveform V0described above. Accordingly, an absolute value |ΔV| of a voltage difference between the waveform V0and the waveform V1varies depending on influence of a conductor such as a finger that is brought into contact with or proximate to the touch panel from the outside. To accurately detect the absolute value |ΔV| of the voltage difference between the waveform V0and the waveform V1, it is more preferable to provide, to an operation of the voltage detector DET, a period Reset for resetting charge and discharge of a capacitor in accordance with a frequency of the AC rectangular wave Sg through switching in the circuit.

The touch panel30illustrated inFIG.1sequentially performs scanning for each detection block in accordance with the drive signal Vcom supplied from the drive electrode driver14to perform mutual capacitance touch detection.

The touch panel30outputs the touch detection signal Vdet1for each detection block via the voltage detector DET illustrated inFIG.3orFIG.5from a plurality of touch detection electrodes TDL described later. The touch detection signal Vdet1is supplied to the touch detection signal amplification unit42of the touch detection unit40.

The touch detection signal amplification unit42amplifies the touch detection signal Vdet1supplied from the touch panel30. The touch detection signal amplification unit42may include an analog low pass filter (LPF) serving as a low-pass analog filter that removes a high frequency component (noise component) included in the touch detection signal Vdet1and outputs the result.

The A/D conversion unit43samples each analog signal output from the touch detection signal amplification unit42at a timing synchronized with the drive signal Vcom, and converts the analog signal into a digital signal.

The signal processing unit44includes a digital filter that reduces a frequency component (noise component) included in the output signal of the A/D conversion unit43, other than a frequency at which the drive signal Vcom is sampled. The signal processing unit44is a logic circuit that detects whether there is a touch on the touch panel30based on the output signal of the A/D conversion unit43. The signal processing unit44performs processing of extracting only a difference of the detection signal caused by the finger. The signal of the difference caused by the finger has the absolute value |ΔV| of the difference between the waveform V0and the waveform V1described above. The signal processing unit44may perform an arithmetic operation for averaging the absolute value |ΔV| for each detection block to obtain an average value of the absolute value |ΔV|. Due to this, the signal processing unit44can suppress influence of the noise. The signal processing unit44compares the detected signal of the difference caused by the finger with a predetermined threshold voltage. If the signal of the difference is smaller than the threshold voltage, the signal processing unit44determines that an external proximity object is in a non-contact state. On the other hand, the signal processing unit44compares the detected signal of the difference caused by the finger with the predetermined threshold voltage. If the signal of the difference is equal to or larger than the threshold voltage, the signal processing unit44determines that the external proximity object is in a contact state. In this way, the touch detection unit40can perform touch detection.

The coordinate extracting unit45is a logic circuit that obtains, when a touch is detected by the signal processing unit44, touch panel coordinates at which the touch is detected. The coordinate extracting unit45outputs the touch panel coordinates as a detection signal output Vout. As described above, the display device1with a touch detection function according to the present embodiment can perform the touch detection operation based on the basic principle of mutual capacitance touch detection.

Next, the following describes a basic principle of self capacitance touch detection with reference toFIGS.7to10.FIG.7is an explanatory diagram representing the state in which the finger is in a non-contact state or a non-proximate state for explaining the basic principle of self capacitance touch detection.FIG.8is an explanatory diagram representing the state in which the finger is in a contact state or a proximate state for explaining the basic principle of self capacitance touch detection.FIG.9is an explanatory diagram illustrating an example of an equivalent circuit of self capacitance touch detection.FIG.10is a diagram representing an example of waveforms of a drive signal and a touch detection signal in self capacitance touch detection.

In the state in which the finger is in a non-contact state or a non-proximate state, the left figure ofFIG.7illustrates a state in which a power source Vdd is coupled to the touch detection electrode E2via a switch SW1and the touch detection electrode E2is not coupled to a capacitor Ccr via a switch SW2. In this state, capacitance Cx1included in the touch detection electrode E2is charged. The right figure ofFIG.7illustrates a state in which the power source Vdd is disconnected from the touch detection electrode E2via the switch SW1and the touch detection electrode E2is coupled to the capacitor Ccr via the switch SW2. In this state, an electric charge of the capacitance Cx1is discharged via the capacitor Ccr.

In the state in which the finger is in a contact state or a proximate state, the left figure ofFIG.8illustrates a state in which the power source Vdd is coupled to the touch detection electrode E2via the switch SW1and the touch detection electrode E2is not coupled to the capacitor Ccr via the switch SW2. In this state, capacitance Cx2caused by the finger that is proximate to the touch detection electrode E2is charged in addition to the capacitance Cx1included in the touch detection electrode E2. The right figure ofFIG.8illustrates a state in which the power source Vdd is disconnected from the touch detection electrode E2via the switch SW1and the touch detection electrode E2is coupled to the capacitor Ccr via the switch SW2. In this state, the electric charge of the capacitance Cx1and an electric charge of the capacitance Cx2are discharged via the capacitor Ccr.

A voltage change characteristic of the capacitor Ccr during discharge (in the state in which the finger is in a contact state or a proximate state) illustrated in the right figure ofFIG.8is obviously different from the voltage change characteristic of the capacitor Ccr during discharge (in the state in which the finger is in a non-contact state or a non-proximate state) illustrated in the right figure ofFIG.7due to presence of the capacitance Cx2. Thus, in a self capacitance system, whether there is an operation input by a finger and the like is determined by utilizing the fact that the voltage change characteristic of the capacitor Ccr varies depending on the presence or absence of the capacitance Cx2.

Specifically, AC rectangular wave Sg (refer toFIG.10) having a predetermined frequency (for example, about several kHz to several hundreds kHz) is applied to the touch detection electrode E2. The voltage detector DET illustrated inFIG.9converts variation in a current corresponding to the AC rectangular wave Sg into variation in a voltage (waveforms V4and V5).

As described above, the touch detection electrode E2is configured to be disconnectable with the switch SW1and the switch SW2. InFIG.10, at a timing of time T01, the AC rectangular wave Sg raises a voltage level corresponding to a voltage V0. At this point, the switch SW1is in an ON state and the switch SW2is in an OFF state. Due to this, the voltage of the touch detection electrode E2is raised to be the voltage V0. Next, the switch SW1is turned OFF before a timing of time T11. Although the touch detection electrode E2is in a floating state at this point, the electric potential of the touch detection electrode E2is kept at V0with the capacitance Cx1(refer toFIG.7) of the touch detection electrode E2or the capacitance (Cx1+Cx2, refer toFIG.8) obtained by adding the capacitance Cx2generated by contact or proximity of a finger and the like to the capacitance Cx1of the touch detection electrode E2. The switch SW3is turned ON before the timing of time T11, and turned OFF after a predetermined time has elapsed to reset the voltage detector DET. Through this reset operation, the output voltage becomes substantially the same voltage as Vref.

Subsequently, when the switch SW2is turned ON at the timing of time T11, a reverse input unit of the voltage detector DET has the voltage V0of the touch detection electrode E2. Thereafter, the voltage of the reverse input unit of the voltage detector DET is lowered to a reference voltage Vref in accordance with a time constant of the capacitance Cx1(or Cx1+Cx2) of the touch detection electrode E2and capacitance C5in the voltage detector DET. At this point, an electric charge accumulated in the capacitance Cx1(or Cx1+Cx2) of the touch detection electrode E2moves to the capacitance C5in the voltage detector DET, so that the output of the voltage detector DET is increased (Vdet2). The output (Vdet2) of the voltage detector DET is represented as the waveform V4of a solid line when a finger and the like are not proximate to the touch detection electrode E2, and Vdet2=Cx1×V0/C5is satisfied. When capacitance caused by a finger and the like is added, the output (Vdet2) is represented as the waveform V5of a dotted line, and Vdet2=(Cx1+Cx2)×V0/C5is satisfied.

Thereafter, at a timing of time T31after the electric charge of the capacitance Cx1(or Cx1+Cx2) of the touch detection electrode E2sufficiently moves to the capacitance C5, the switch SW2is turned OFF and the switch SW1and the switch SW3are turned ON, and thus the electric potential of the touch detection electrode E2is caused to be at a low level that is the same as the electric potential of the AC rectangular wave Sg, and the voltage detector DET is reset. In this case, a timing for turning ON the switch SW1may be any timing after the switch SW2is turned OFF and before time T02. A timing for resetting the voltage detector DET may be any timing after the switch SW2is turned OFF and before time112. The above operation is repeated at a predetermined frequency (for example, about several kHz to several hundreds kHz). It can be measured whether there is an external proximity object (whether there is a touch) based on an absolute value |ΔV| of a difference between the waveform V4and the waveform V5. As illustrated inFIG.10, the electric potential of the touch detection electrode E2is represented as the waveform V2when a finger and the like are in a non-proximate state, and represented as the waveform V3when the capacitance Cx2caused by a finger and the like is added. As a detection method, for example, it can be measured whether there is an external proximity object (whether there is a touch) by measuring a time until each of the waveform V2and the waveform V3is lowered to a predetermined voltage VTH.

Next, the following describes a configuration example of the display device1with a touch detection function in detail.FIG.11is a cross-sectional view representing a schematic cross-sectional structure of the display device with a touch detection function.FIG.12is a plan view schematically illustrating a TFT substrate configuring the display device with a touch detection function.FIG.13is a plan view schematically illustrating a glass substrate configuring the display device with a touch detection function.

As illustrated inFIG.11, the display device1with a touch detection function includes a pixel substrate2, a counter substrate3arranged to be opposed to a surface of the pixel substrate2in a perpendicular direction, and a liquid crystal layer6interposed between the pixel substrate2and the counter substrate3.

As illustrated inFIG.11, the pixel substrate2includes a thin film transistor (TFT) substrate21serving as a circuit board, a plurality of pixel electrodes22arranged in a matrix above the TFT substrate21, a plurality of drive electrodes COML arranged between the TFT substrate21and the pixel electrodes22, and an insulating layer24that insulates the pixel electrode22from the drive electrode COML. A polarizing plate35B may be arranged under the TFT substrate21with a bonding layer interposed therebetween (not illustrated).

As illustrated inFIG.12, the TFT substrate21includes a display region10afor displaying an image and a frame region10barranged around the display region10a. The display region10ahas a rectangular shape having a pair of long sides and a pair of short sides. The frame region10bhas a frame shape surrounding four sides of the display region10a.

The drive electrodes COML are arranged in the display region10aof the TFT substrate21, and arrayed in a matrix in a direction along the long side of the display region10aand a direction along the short side thereof. Each of the drive electrodes COML has a rectangular shape or a square shape. The drive electrode COML is made of, for example, a translucent conductive material such as indium tin oxide (ITO). A plurality of pixel electrodes22are arranged in a matrix at a position corresponding to one drive electrode COML. An area of the pixel electrode22is smaller than that of the drive electrode COML. AlthoughFIG.12illustrates part of the drive electrodes COML and the pixel electrodes22, the drive electrodes COML and the pixel electrodes22are arranged over the entire display region10a. In the present embodiment, a plurality of drive electrodes COML arranged in a row direction may be driven at the same time, serving as one drive electrode block COMLA.

The drive electrode driver14and a display control IC19are arranged on the short side of the frame region10bof the TFT substrate21. A flexible substrate (not illustrated) is coupled to the short side of the frame region10b, and is coupled to the display control IC19and/or the drive electrode driver14. Wires37are coupled to the respective drive electrodes COML, and are drawn out to the short side of the frame region10b. The drive electrode driver14is coupled to each of the drive electrodes COML via the wires37arranged in the display region10a. Due to this, the drive electrode driver14is not required to be arranged on the long side of the frame region10b, so that the width of the frame region10bon the long side can be reduced.

The display control IC19is a chip mounted on the TFT substrate21using a chip on glass (COG) system, and incorporates the control unit11described above. The display control IC19outputs a control signal to a gate line GCL for display, a data line SGL for display (described later), and the like based on the video signal Vdisp (refer toFIG.1) supplied from an external host IC (not illustrated).

As illustrated inFIG.11, the counter substrate3includes a glass substrate31and a color filter32formed on one face of the glass substrate31. The touch detection electrode TDL serving as a detection electrode of the touch panel30is arranged on the other face of the glass substrate31. A polarizing plate35A is arranged above the touch detection electrode TDL with a bonding layer interposed therebetween (not illustrated). A flexible substrate (not illustrated) is coupled to the glass substrate31. The flexible substrate is coupled to the touch detection electrode TDL via the frame wire.

As illustrated inFIG.13, a plurality of touch detection electrodes TDL are arranged in the display region10aof the glass substrate31. The touch detection electrodes TDL each extend in a direction along the long side of the display region10a, and are arrayed in a direction along the short side of the display region10a. Each touch detection electrode TDL includes two detection electrodes TDLa and TDLb, and coupling parts TDLc and TDLc that couple the detection electrode TDLa to the detection electrode TDLb. The two detection electrodes TDLa and TDLb extend in the direction along the long side of the display region10aand parallel with each other. The coupling parts TDLc are arranged on both ends of the detection electrodes TDLa and TDLb.

As illustrated inFIG.11, the TFT substrate21and the glass substrate31are arranged to be opposed to each other with a predetermined gap therebetween. The liquid crystal layer6is arranged in a space between the TFT substrate21and the glass substrate31. The liquid crystal layer6modulates light passing therethrough depending on a state of an electric field. For example, used are liquid crystals of lateral electric-field mode such as in-plane switching (IPS) including fringe field switching (FFS). An orientation film may be arranged between the liquid crystal layer6and the pixel substrate2, and between the liquid crystal layer6and the counter substrate3illustrated inFIG.11.

Next, the following describes a display operation of the display panel20.FIG.14is a circuit diagram representing a pixel array of the display unit with a touch detection function according to the first embodiment. In the TFT substrate21illustrated inFIG.11, formed are a switching element TrD for display of each sub-pixel SPix illustrated inFIG.14, and wires such as the data line SGL for display for supplying the pixel signal Vpix to each pixel electrode22and the gate line GCL for display for supplying a drive signal for driving each switching element TrD for display. The data line SGL for display and the gate line GCL for display extend along a plane parallel with the surface of the TFT substrate21.

The display panel20illustrated inFIG.14includes a plurality of sub-pixels SPix arranged in a matrix. Each sub-pixel SPix includes the switching element TrD for display and a liquid crystal element LC. The switching element TrD for display is constituted of a thin film transistor. In this example, the switching element TrD for display is constituted of an n-channel metal oxide semiconductor (MOS) TFT. A source of the switching element TrD for display is coupled to the data line SGL for display, a gate thereof is coupled to the gate line GCL for display, and a drain thereof is coupled to one end of the liquid crystal element LC. In the equivalent circuit, one end of the liquid crystal element LC including the liquid crystal layer6is coupled to the drain of the switching element TrD for display, and the other end thereof is coupled to each drive electrode COML included in the drive electrode block COMLA. The insulating layer24is arranged between the pixel electrode22and the common electrode (drive electrode COML), which forms holding capacitance Cs illustrated inFIG.14.

The sub-pixel SPix is mutually coupled to the other sub-pixel SPix belonging to the same row in the display panel20via the gate line GCL for display. The gate line GCL for display is coupled to the gate driver12(refer toFIG.1), and receives the scanning signal Vscan supplied from the gate driver12. The sub-pixel SPix is mutually coupled to the other sub-pixel SPix belonging to the same column in the display panel20via the data line SGL for display. The data line SGL for display is coupled to the source driver13(refer toFIG.1), and receives the pixel signal Vpix supplied from the source driver13. Each drive electrode COML included in the drive electrode block COMLA is coupled to the drive electrode driver14(refer toFIG.1), and receives the drive signal Vcom supplied from the drive electrode driver14.

The gate driver12illustrated inFIG.1drives the gate line GCL for display to sequentially perform scanning. The gate driver12applies the scanning signal Vscan (refer toFIG.1) to a gate of a TFT element Tr of the sub-pixel SPix via the gate line GCL for display. Accordingly, one line (one horizontal line) of the sub-pixels SPix is sequentially selected as a display driving target. The source driver13supplies the pixel signal Vpix to the sub-pixels SPix belonging to the selected one horizontal line via the data line SGL for display illustrated inFIG.14. In performing the display operation for each horizontal line as described above, the drive electrode driver14applies the drive signal Vcom (display drive signal Vcomdc) to the drive electrode COML. Due to this, each drive electrode COML functions as a common electrode for the pixel electrode22at the time of display.

In the color filter32illustrated inFIG.11, for example, color regions of the color filter colored in three colors of red (R), green (G), and blue (B) may be periodically arranged. Color regions32R,32G, and32B of three colors R, G, and B are associated, as one set, with each of the sub-pixels SPix illustrated inFIG.14, and a pixel Pix is constituted of a set of sub-pixels SPix corresponding to the color regions32R,32G, and32B of three colors. As illustrated inFIG.11, the color filter32is opposed to the liquid crystal layer6in a direction perpendicular to the TFT substrate21. Another combination of colors may be used for the color filter32so long as the colors are different from each other. The combination of colors for the color filter32is not limited to three colors. Alternatively, four or more colors may be combined.

As illustrated inFIG.14, in the present embodiment, the drive electrode block COMLA including a plurality of drive electrodes COML is arranged along the gate line GCL for display. Alternatively, the drive electrode block COMLA is arranged to intersect with the data line SGL for display. The arrangement of the drive electrode block COMLA is not limited thereto. The drive electrode block COMLA may be arranged along the data line SGL for display, for example.

The drive electrode COML illustrated inFIGS.11and12functions as a common electrode that gives a common potential (reference potential) to the pixel electrodes22of the display panel20. The drive electrode COML also functions as a drive electrode for performing mutual capacitance touch detection of the touch panel30. The drive electrode COML may also function as a detection electrode for performing self capacitance touch detection of the touch panel30.FIG.15is a perspective view representing a configuration example of the drive electrode and the touch detection electrode of the display unit with a touch detection function according to the first embodiment. The touch panel30is constituted of the drive electrode COML arranged in the pixel substrate2and the touch detection electrode TDL arranged in the counter substrate3.

The drive electrode block COMLA including a plurality of drive electrodes COML functions as a plurality of stripe electrode patterns extending in a horizontal direction ofFIG.15. The touch detection electrode TDL includes a plurality of electrode patterns intersecting with a plurality of drive electrode blocks COMLA. The touch detection electrode TDL is opposed to the drive electrode block COMLA in a direction perpendicular to the surface of the TFT substrate21(refer toFIG.11). Each electrode pattern of the touch detection electrode TDL is coupled to an input of the touch detection signal amplification unit42(refer toFIG.1). Capacitance is generated at each intersecting portion between each drive electrode COML of the drive electrode block COMLA and each electrode pattern of the touch detection electrode TDL.

The shape of the touch detection electrode TDL and the drive electrode COML (drive electrode block COMLA) is not limited to a plurality of stripes. For example, the touch detection electrode TDL may have a comb-teeth shape and the like. Alternatively, it is sufficient that the touch detection electrode TDL is divided into a plurality of parts, and a slit that divides the drive electrode COML may have a linear shape or a curved shape.

When the touch panel30performs a mutual capacitance touch detection operation, the drive electrode block COMLA is sequentially scanned one by one in a time division manner by the drive electrode driver14. Accordingly, the drive electrode COML of the drive electrode block COMLA is sequentially selected. The touch detection signal Vdet1is output to the selected drive electrode block COMLA from the touch detection electrode TDL. The drive electrode block COMLA corresponds to the drive electrode E1in the basic principle of mutual capacitance touch detection described above, and the touch detection electrode TDL corresponds to the touch detection electrode E2. The touch panel30detects a touch input in accordance with the basic principle. As illustrated inFIG.15, in the touch panel30, the touch detection electrode TDL and the drive electrode block COMLA intersecting with each other constitute a capacitance touch sensor in a matrix. Thus, by sequentially driving each drive electrode block COMLA, a position where an external conductor is brought into contact with or proximate to the touch panel30can be detected.

As an example of an operating method of the display device1with a touch detection function, the display device1with a touch detection function performs a touch detection operation (touch period) and a display operation (display period) in a time division manner. The touch detection operation and the display operation may be separately performed in any manner. The following describes a method of performing the touch detection operation and the display operation while dividing each operation into a plurality of parts within one frame period (1F period) of the display panel20, that is, within time required for displaying video information corresponding to one screen.

FIG.16is a schematic diagram representing an example of arrangement of the display period and the touch period within one frame period. One frame period (1F) includes two display periods Pd1and Pd2, and two touch periods Pt1and Pt2. These periods are arranged so that the display period and the touch period are alternately set on a time axis as follows: the display period Pd1, the touch period Pt1, the display period Pd2, and the touch period Pt2.

The control unit11(refer toFIG.1) supplies pixel signals Vpix to a plurality of rows of pixels Pix (refer toFIG.14) selected in each of the display periods Pd1and Pd2via the gate driver12and the source driver13.

The control unit11(refer toFIG.1) supplies a drive signal Vcom for touch detection (touch drive signal Vcomac) to the drive electrode COML (drive electrode block COMLA) (refer toFIG.15) selected in each of the touch periods Pt1and Pt2via the drive electrode driver14. Based on the touch detection signal Vdet1supplied from the touch detection electrode TDL, the touch detection unit40detects whether there is a touch input and performs an arithmetic operation of coordinates of an input position.

In the present embodiment, the drive electrode COML also functions as a common electrode of the display panel20. Thus, the control unit11supplies the display drive signal Vcomdc having a common electrode potential for display to the drive electrode COML in the display periods Pd1and Pd2.

When touch detection is performed based on a change in self capacitance of the drive electrode COML without using the touch detection electrode TDL for the touch detection operation, the drive electrode driver14supplies the touch drive signal Vcomac to each drive electrode COML, and based on the touch detection signal Vdet2supplied from each drive electrode COML, the touch detection unit40detects whether there is a touch input and performs an arithmetic operation of coordinates of the input position.

InFIG.16, video display for one screen is assumed to be performed while being divided into two parts within one frame period (1F). Alternatively, the display period within one frame period (1F) may be divided into a larger number of parts. The touch period may also be divided into a larger number of parts within one frame period (1F).

In each of the touch periods Pt1and Pt2, touch detection for a half of one screen may be performed, or touch detection for one screen may be performed. Thinning-out detection and the like may be performed as needed. Each of the display operation and the touch detection operation may be performed once within one frame period (1F) without being divided into a plurality of parts.

In the touch periods Pt1and Pt2, the gate line GCL for display and the data line SGL for display (refer toFIG.14) may be in a floating state in which a voltage signal is not supplied and electric potential is not fixed. As described later, signals having the same waveform and being synchronized with the touch drive signal Vcomac may be supplied to the gate line GCL for display and the data line SGL for display.

Next, the following describes a detailed configuration of the display panel20according to the present embodiment.FIG.17is a plan view for explaining a configuration of the pixel electrode and the switching element for the display panel according to the first embodiment.

As illustrated inFIG.17, a plurality of pixel electrodes22are arranged in a matrix at a position overlapped with one drive electrode COML. The switching element TrD for display is arranged at a position corresponding to each of the pixel electrodes22. A plurality of gate lines GCL for display each extend in a row direction, and are arranged in a column direction. A plurality of data lines SGL for display each extend in the column direction intersecting with an extending direction of the gate line GCL for display, and are arranged in the row direction. The switching element TrD for display is arranged at an intersecting part of the gate line GCL for display and the data line SGL for display. A region surrounded by the gate line GCL for display and the data line SGL for display is the sub-pixel SPix. The sub-pixel SPix is arranged to include a region where the pixel electrode22overlaps with the drive electrode COML.

In the present embodiment, a conductive wire51is arranged at a position overlapped with the data line SGL for display. A plurality of conductive wires51each extend in the column direction that is the same as the extending direction of the data line SGL for display, and are arranged in the row direction. The conductive wire51is formed at a position that is overlapped with the drive electrode COML and not overlapped with the pixel electrode22. The conductive wire51includes a tab part51aprojecting toward a position overlapping with the gate line GCL for display. At a position overlapped with the tab part51a, the gate line GCL for display is electrically coupled to the conductive wire51via a contact hole H4. A gate line for display in the m-th row is assumed to be a gate line GCL(m) for display, a data line for display in the n-th column is assumed to be a data line SGL(n) for display, and a conductive wire in the n-th column is represented as a conductive wire51(n). The conductive wire51(n) is coupled to the gate line GCL(m) for display, the conductive wire51(n+1) is coupled to a gate line GCL(m+1) for display, and the conductive wire51(n+2) is coupled to a gate line GCL(m+2) for display. In this way, the conductive wires51are coupled to different gate lines GCL for display, respectively.

The conductive wire51is coupled to the gate driver12arranged in the frame region10b. The gate driver12includes shift registers SR<n>, SR<n+1>, SR<n+2>, SR<n+3>, and SR<n+4>. The conductive wires51(n),51(n+1),51(n+2),51(n+3), and51(n+4) are coupled to the shift registers SR<n>, SR<n+1>, SR<n+2>, SR<n+3>, and SR<n+4>, respectively. The gate driver12sequentially scans the conductive wires51, and supplies the scanning signal Vscan to a selected conductive wire51. The scanning signal Vscan is transmitted to the gate line GCL for display via the conductive wire51, and supplied to a plurality of switching elements TrD for display coupled to the gate line GCL for display. The switching element TrD for display is switched between ON and OFF with the scanning signal Vscan.

In the present embodiment, the conductive wire51is coupled to the gate line GCL for display, extends in a direction intersecting with the gate line GCL for display, and is drawn out to the short side of the frame region10b. Thus, the gate driver12can be arranged on the short side of the frame region10b. The present embodiment employs a configuration in which the gate driver12is arranged at a position on the same side as the display control IC19of one pair of short side portions of the frame region10b. Alternatively, a configuration can be employed in which the gate driver12is arranged on a short side portion opposite to a side on which the display control IC19is arranged. This configuration can further reduce the width on the long side of the frame region10b.

The conductive wire51is made of a metallic material that is at least one of aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), and alloy thereof. The conductive wire51may be a laminate obtained by laminating a plurality of metallic materials using one or more of these metallic materials.

Next, with reference toFIGS.18and19, the following describes a coupling structure between the conductive wire51and the switching element TrD for display.FIG.18is a plan view of the TFT substrate for explaining a configuration of the sub-pixel.FIG.19is a cross-sectional view along the line XIX-XIX′ inFIG.18.

As illustrated inFIG.18, a longitudinal direction of the pixel electrode22corresponds to the extending direction of the data line SGL for display. The pixel electrode22includes a plurality of strip electrodes22aand a connecting part22b. The strip electrodes22aeach extend in the extending direction of the data line SGL for display, and are arranged in the extending direction of the gate line GCL for display. The connecting part22bconnects ends of the strip electrode22awith each other. The pixel electrode22is coupled to a drain electrode63of the switching element TrD for display via a contact hole H1.

As illustrated inFIGS.18and19, the switching element TrD for display includes a semiconductor layer61, a source electrode62, the drain electrode63, and a gate electrode64. A light shielding layer54is arranged below the semiconductor layer61.

As illustrated inFIG.19, an insulating layer58ais arranged on the TFT substrate21while covering the light shielding layer54. The semiconductor layer61is arranged on the insulating layer58a. An insulating layer58bis arranged on the semiconductor layer61, and the gate line GCL for display is arranged on the insulating layer58b. An insulating layer58cis arranged on the gate line GCL for display, and the drain electrode63and the data line SGL for display are arranged on the insulating layer58c. An insulating layer58dis arranged on the drain electrode63and the data line SGL for display, and the conductive wire51is arranged on the insulating layer58d. An insulating layer58eis arranged on the conductive wire51, and the drive electrode COML is arranged on the insulating layer58e. As described above, the insulating layer24is arranged on the drive electrode COML, and the pixel electrode22is arranged on the insulating layer24.

The semiconductor layer61is coupled to the drain electrode63via a contact hole H2. The semiconductor layer61is bent to intersect with the gate line GCL for display multiple times in a plan view. A portion of the gate line GCL for display overlapped with the semiconductor layer61functions as the gate electrode64. The semiconductor layer61extends to a position overlapped with the data line SGL for display, and is electrically coupled to the data line SGL for display via a contact hole H3. A portion of the data line SGL for display overlapped with the semiconductor layer61functions as the source electrode62.

As a material for the semiconductor layer61, a known material such as polysilicon and an oxide semiconductor can be used. For example, a transparent amorphous oxide semiconductor (TAOS) is used to improve a capability for retaining a voltage for video display for a long time (retaining rate), thereby improving display quality.

A channel part is arranged at a portion of the semiconductor layer61overlapped with the gate electrode64. It is preferred that the light shielding layer54is arranged at a position overlapping with the channel part, and has a larger area than that of the channel part. Due to the light shielding layer54, for example, light incident on the semiconductor layer61from a backlight is shielded.

As illustrated inFIG.18, the conductive wire51is arranged to be overlapped with the data line SGL for display. The tab part51ais arranged at the intersecting part of the data line SGL for display and the gate line GCL for display, and projects in a direction intersecting with an extending direction of the conductive wire51. The tab part51ais arranged at a position that is overlapped with the gate line GCL for display and not overlapped with the data line SGL for display. The tab part51ais electrically coupled to the gate line GCL for display via the contact hole H4. In this way, the conductive wire51is electrically coupled to the switching element TrD for display.

As described above, the conductive wire51is arranged in a layer different from that of the drive electrode COML via the insulating layer58e, and is coupled to the switching element TrD for display via the gate line GCL for display. The conductive wire51is used as a gate line for supplying the scanning signal Vscan to the switching element TrD for display, so that a degree of freedom of wiring arranged within the display region10acan be improved. Accordingly, a degree of freedom of design of a circuit and the like arranged in the frame region10bis improved. For example, as illustrated inFIG.17, the gate driver12on the short side of the frame region10bis arranged so that the long side of the frame region10bcan be narrowed.

In the present embodiment, the width of the conductive wire51is larger than that of the data line SGL for display, so that the data line SGL for display can be prevented from being visually recognized. The embodiment is not limited thereto. The width of the conductive wire51may be the same as that of the data line SGL for display, or smaller than that of the data line SGL for display. The configuration is not limited to the conductive wire51being arranged to be overlapped with all the data lines SGL for display. A configuration may be employed in which the conductive wire51is not overlapped with some of the data lines SGL for display.

The pixel electrode22illustrated inFIG.18is patterned in a strip shape, but the embodiment is not limited thereto. The pixel electrode22may be formed in a flat plate shape. In this case, the drive electrode COML includes one or a plurality of strip electrodes, for example. Although the pixel electrode22is arranged on an upper layer side (a side closer to the liquid crystal layer) than the drive electrode COML, the drive electrode COML may be arranged on an upper layer side than the pixel electrode22. The drive electrode COML and the pixel electrode22may be arranged adjacent to each other on the same layer. For example, each of the drive electrode COML and the pixel electrode22is formed as a strip electrode, and the drive electrode COML and the pixel electrode22may be arranged apart from each other without being overlapped with each other in a plan view.

Second Embodiment

FIG.20is a plan view illustrating a pixel substrate according to a second embodiment. As illustrated inFIG.20, the drive electrodes COML are arranged in a matrix in the display region10aof the TFT substrate21, and the pixel electrodes22are arranged in a matrix overlapping with the drive electrodes COML. In the present embodiment, the display region10ais divided into a first display region10cand a second display region10dfor driving control. The first display region10cis a region closer to the display control IC19, and the second display region10dis a region that is adjacent to the first display region10cand is distant from the display control IC19as compared with the first display region10c. A first gate driver12A and a second gate driver12B are arranged in the frame region10bof the TFT substrate21. The first gate driver12A and the second gate driver12B are arranged on the long side of the frame region10b. Two first gate drivers12A are arranged with the first display region10cinterposed therebetween, and two second gate drivers12B are arranged with the second display region10dinterposed therebetween.

The first gate driver12A sequentially selects one line (one horizontal line) of the sub-pixels SPix (refer toFIG.14) in the first display region10cas a display driving target. The second gate driver12B sequentially selects one line (one horizontal line) of the sub-pixels SPix in the second display region10das a display driving target. The first gate driver12A and the second gate driver12B can be driven for scanning at the same time, so that the screen size of the display region10acan be increased and definition of the sub-pixels SPix can be improved.

FIG.21is a plan view for explaining a configuration of the pixel electrode and the switching element for display according to the second embodiment.FIG.22is a plan view of the TFT substrate for explaining a configuration of the sub-pixel in the first display region according to the second embodiment.FIG.23is a cross-sectional view along the line XXIII-XXIII′ inFIG.22.FIG.24is a plan view of the TFT substrate for explaining a configuration of the sub-pixel in the second display region according to the second embodiment.FIG.25is a cross-sectional view along the line XXV-XXV′ inFIG.24.

As illustrated inFIG.21, the first gate driver12A is coupled to the switching element TrD for display via a first gate line GCL1for display. The second gate driver12B is coupled to the switching element TrD for display via a second gate line GCL2for display. In the first display region10c, a first data line SGL1for display extends in a direction intersecting with an extending direction of the first gate line GCL1for display, and the switching element TrD for display is coupled to the first data line SGL1for display. The conductive wire51is arranged at a position overlapping with the first data line SGL1for display. The conductive wire51extends over the first display region10cand the second display region10d. The switching element TrD for display in the second display region10dis coupled to the conductive wire51via a second data line SGL2for display.

As illustrated inFIGS.22and23, the configuration of the switching element TrD for display and the pixel electrode22according to the present embodiment is similar to that in the first embodiment. The switching element TrD for display in the first display region10cis arranged so that the semiconductor layer61intersects with the first gate line GCL1for display in a plan view. As illustrated inFIG.23, the semiconductor layer61is coupled to the first data line SGL1for display via the contact hole H3. The conductive wire51is arranged to be overlapped with the first data line SGL1for display, and is not coupled to the first gate line GCL1for display and the first data line SGL1for display. That is, the conductive wire51is not coupled to the switching element TrD for display in the first display region10c.

As illustrated inFIGS.24and25, the switching element TrD for display in the second display region10dis arranged so that the semiconductor layer61intersects with the second gate line GCL2for display in a plan view. The semiconductor layer61is coupled to the second data line SGL2for display via the contact hole H3. The second data line SGL2for display is electrically coupled to the conductive wire51via a contact hole H5. In this way, the conductive wire51is coupled to the switching element TrD for display in the second display region10d. The second data line SGL2for display is arranged apart from the first data line SGL1for display in the same layer as that of the first data line SGL1for display illustrated inFIG.23. As illustrated inFIG.21, the second data line SGL2for display is arranged in each of the switching elements TrD for display in the second display region10d, and the switching elements TrD for display arranged in the column direction are coupled to one conductive wire51via the second data line SGL2for display.

FIG.26is a plan view for explaining a coupling structure between the display control IC and wires. As illustrated inFIG.26, the first data line SGL1for display is coupled to the switching element TrD for display in the first display region10c, and drawn out to the frame region10bin which the display control IC19is arranged. The first data line SGL1for display is coupled to the display control IC19via a coupling wire37a. The conductive wire51is coupled to the switching element TrD for display in the second display region10d, extends to be overlapped with the first data line SGL1for display in the first display region10c, and is drawn out to the frame region10bin which the display control IC19is arranged. The conductive wire51is coupled to coupling wire37bvia a contact hole H6in the frame region10b. The conductive wire51is coupled to the display control IC19via the coupling wire37b. In this way, the switching element TrD for display in the first display region10cand the switching element TrD for display in the second display region10dare coupled to the one display control IC19.

As described above, the conductive wire51according to the present embodiment is used as a data line for display for supplying the pixel signal Vpix to the switching element TrD for display in the second display region10d. Thus, when the display control IC19scans the first data line SGL1for display and the conductive wire51at the same time while supplying the pixel signal Vpix to each of the selected first data line SGL1for display and a selected conductive wire51, a display operation in the first display region10cand the second display region10dcan be performed at the same time. When the conductive wire51is used as the data line for display, a degree of freedom of wiring within the display region10ais improved, so that display driving suitable for increasing the screen size of the display region10aand improving definition of the sub-pixels SPix can be implemented.

The conductive wire51is overlapped with the first data line SGL1for display and the second data line SGL2for display, and is longer than the first data line SGL1for display and the second data line SGL2for display. Due to this, the first data line SGL1for display and the second data line SGL2for display can be made invisible.

In the present embodiment, the display region10ais divided into the first display region10cand the second display region10d, and the conductive wire51is coupled to the switching element TrD for display on the second display region10dside. However, the embodiment is not limited thereto. For example, the data line SGL for display may be coupled to the switching element TrD for display in an odd number column, and the conductive wire51may be coupled to the switching element TrD for display in an even number column. In this case, the data line SGL for display and the conductive wire51may be coupled to different scanning driving units, and a display operation may be performed for every two lines including one data line SGL for display and one conductive wire51at the same time.

Third Embodiment

FIG.27is a plan view for explaining a coupling structure between the drive electrode and a switching element for touch according to a third embodiment. As illustrated inFIG.27, in the touch panel30according to the present embodiment, a gate line GCLT for touch is arranged to be overlapped with the drive electrode block COMLA including the drive electrodes COML arranged in the row direction. The gate line GCLT for touch is arranged corresponding to each of a plurality of drive electrode blocks COMLA arranged in the column direction. An end of the gate line GCLT for touch is coupled to the gate driver12(a gate driver12C for touch).

Two conductive wires52A and52B are arranged corresponding to one drive electrode COML. The conductive wires52A and52B extend in parallel with each other in a direction intersecting with the gate line GCLT for touch, that is, the column direction while being overlapped with the drive electrodes COML arranged in the column direction. Ends of the conductive wires52A and52B are coupled to the drive electrode driver14.

A first switching element TrT1for touch is arranged at a portion where the gate line GCLT for touch intersects with the conductive wire52A, and a second switching element TrT2for touch is arranged at a portion where the gate line GCLT for touch intersects with the conductive wire52B. Two TFT elements (the first switching element TrT1for touch and the second switching element TrT2for touch) are arranged corresponding to one drive electrode COML, and one gate line GCLT for touch is coupled to the first switching element TrT1for touch and the second switching element TrT2for touch corresponding to one drive electrode COML.

The first switching element TrT1for touch and the second switching element TrT2for touch perform switching operations reverse to each other. When the same scanning signal is supplied to the first switching element TrT1for touch and the second switching element TrT2for touch, and the scanning signal is at a high level, for example, the first switching element TrT1for touch is turned ON (opened), and the second switching element TrT2for touch is turned OFF (closed). When the scanning signal is at a low level, the first switching element TrT1for touch is turned OFF (closed), and the second switching element TrT2for touch is turned ON (opened). For example, the first switching element TrT1for touch is an n-type TFT element, and the second switching element TrT2for touch is a p-type TFT element.

As illustrated inFIG.27, the drive electrode driver14includes a drive signal generation unit14A that generates the drive signal, and wires LAC and LDC. The drive signal generation unit14A generates the touch drive signal Vcomac for touch detection, and the display drive signal Vcomdc having a common potential for the display operation. The drive signal generation unit14A outputs the touch drive signal Vcomac to the wire LAC, and outputs the display drive signal Vcomdc to the wire LDC.

The wire LAC is coupled to the conductive wire52A. The touch drive signal Vcomac is supplied to the first switching element TrT1for touch via the conductive wire52A. The wire LDC is coupled to the conductive wire52B. The display drive signal Vcomdc is supplied to the second switching element TrT2for touch via the conductive wire52B.

The gate driver12includes shift registers SR, and the gate lines GCLT (n), GCLT(n+1), and GCLT(n+2) for touch are coupled to the shift registers SR<n>, SR<n+1>, and SR<n+2>, respectively. The gate driver12scans the gate line GCLT for touch, and a scanning drive signal is supplied to a selected gate line GCLT for touch. The first switching element TrT1for touch coupled to the selected gate line GCLT for touch is turned ON, and the second switching element TrT2for touch coupled thereto is turned OFF. Accordingly, the touch drive signal Vcomac is supplied to the drive electrode COML (drive electrode block COMLA) overlapped with the selected gate line GCLT for touch via the conductive wire52A.

The first switching element TrT1for touch coupled to a non-selected gate line GCLT for touch is turned OFF, and the second switching element TrT2for touch coupled thereto is turned ON. Accordingly, the touch drive signal Vcomac is not supplied to the drive electrode COML (drive electrode block COMLA) overlapped with the non-selected gate line GCLT for touch, and the display drive signal Vcomdc is supplied thereto via the conductive wire52B.

When the gate driver12sequentially selects the gate line GCLT for touch, and the drive electrode driver14supplies the touch drive signal Vcomac to the drive electrode COML (drive electrode block COMLA) coupled to the selected gate line GCLT for touch, contact or proximity of an external conductor can be detected based on the principle of mutual capacitance touch detection described above.

Next, the following describes a coupling structure between the drive electrode COML and the conductive wires52A and52B.FIG.28is a plan view for explaining a configuration of the drive electrode and the pixel electrode according to the third embodiment.FIG.29is a cross-sectional view along the line XXIX-XXIX′ inFIG.28.

As illustrated inFIG.28, a plurality of pixel electrodes22are arranged to be overlapped with one drive electrode COML. The pixel electrodes22are coupled to the gate line GCL for display and the data line SGL for display via the switching element TrD for display. InFIG.28, five columns of pixel electrodes22are arranged for one drive electrode COML, but the embodiment is not limited thereto. Six or more columns of pixel electrodes22may be arranged, or four or less columns of pixel electrodes22may be arranged. The configuration of the switching element TrD for display according to the present embodiment is similar to that of the first embodiment and the second embodiment, except that the conductive wires52A and52B are not coupled to the gate line GCL for display, and the conductive wires52A and52B are not coupled to the data line SGL for display.

As illustrated inFIG.28, the gate line GCLT for touch is arranged along one gate line GCL for display. The gate line GCLT for touch extends in the row direction, and is arranged at a position not overlapped with the pixel electrode22between the pixel electrodes22adjacent to each other in the column direction. The conductive wire52A is arranged to be overlapped with one data line SGL for display. The conductive wiring52A extends in the column direction while intersecting with the gate line GCLT for touch. The conductive wire52B is arranged to be overlapped with the data line SGL for display at a position different from that of the conductive wire52A. The conductive wire52B extends in the column direction while intersecting with the gate line GCLT for touch. The conductive wire52A and the conductive wire52B are formed at a position that is overlapped with the drive electrode COML and not overlapped with the pixel electrode22.

The conductive wire52A includes a tab part52aprojecting toward a position not overlapped with the data line SGL for display. The conductive wire52A is coupled to the first switching element TrT1for touch via the tab part52a. Similarly, the conductive wire52B includes a tab part52bprojecting toward a position not overlapped with the data line SGL for display. The conductive wire52B is coupled to the second switching element TrT2for touch via the tab part52b.

As illustrated inFIG.29, the first switching element TrT1for touch includes a semiconductor layer71, a source electrode72, a drain electrode73, and a gate electrode74. The second switching element TrT2for touch includes a semiconductor layer81, a source electrode82, a drain electrode83, and a gate electrode84.

An end of the semiconductor layer71in the first switching element TrT1for touch is coupled to the source electrode72via a contact hole HT2. The source electrode72is coupled to the conductive wire52A via a contact hole HT1. The other end of the semiconductor layer71is coupled to the drain electrode73via a contact hole HT3. The drain electrode73is coupled to the drive electrode COML via a contact hole HT4. The gate line GCLT for touch at a portion overlapped with the semiconductor layer71functions as the gate electrode74. In this way, the conductive wire52A is coupled to the drive electrode COML via the first switching element TrT1for touch.

An end of the semiconductor layer81in the second switching element TrT2for touch is coupled to the source electrode82via a contact hole HT6. The source electrode82is coupled to the conductive wire52B via a contact hole HT5. The other end of the semiconductor layer81is coupled to the drain electrode83via a contact hole HT7. The drain electrode83is coupled to the drive electrode COML via a contact hole HT8. The gate line GCLT for touch at a portion overlapped with the semiconductor layer81functions as the gate electrode84. In this way, the conductive wire52B is coupled to the drive electrode COML via the second switching element TrT2for touch.

The semiconductor layer71and the semiconductor layer81are arranged in the same layer as the semiconductor layer61of the switching element TrD for display, and on the insulating layer58a. The insulating layer58bis arranged on the semiconductor layer61, the semiconductor layer71, and the semiconductor layer81. The gate electrode74and the gate electrode84(gate lines GCLT for touch) are arranged in the same layer as the gate electrode64(gate line GCL for display) of the switching element TrD for display, and on the insulating layer58b. The insulating layer58cis arranged on the gate electrode64, the gate electrode74, and the gate electrode84. The source electrode72, the drain electrode73, the source electrode82, and the drain electrode83are arranged in the same layer as the source electrode62and the drain electrode63of the switching element TrD for display, and on the insulating layer58c. The insulating layer58dis arranged on the source electrode62, the drain electrode63, the source electrode72, the drain electrode73, the source electrode82, and the drain electrode83.

The conductive wire52A and the conductive wire52B are arranged on the insulating layer58d, and the insulating layer58eis arranged on the conductive wire52A and the conductive wire52B. The drive electrode COML is arranged on the insulating layer58e. That is, the conductive wire52A and the conductive wire52B are arranged in a layer different from that of the drive electrode COML via the insulating layer58e. The conductive wire52A and the conductive wire52B are arranged in the same layer, but the embodiment is not limited thereto. The conductive wire52A and the conductive wire52B may be arranged in different layers. The first switching element TrT1for touch and the second switching element TrT2for touch are arranged in the same layer as the switching element TrD for display, but the embodiment is not limited thereto. The first switching element TrT1for touch and the second switching element TrT2for touch may be arranged in a layer different from that of the switching element TrD for display. In view of visibility, the first switching element TrT1for touch and the second switching element TrT2for touch are preferably arranged in the sub-pixel SPix corresponding to the color region32B of blue described above.

Next, the following describes an example of a driving method according to the present embodiment.FIG.30is a timing waveform chart illustrating an operation example of the display device with a touch detection function according to the third embodiment. As illustrated inFIG.30, the display periods Pd1, Pd2, Pd3. . . and the touch periods Pt1, Pt2, Pt3. . . are alternately arranged in a time division manner. In the display periods Pd1, Pd2, Pd3. . . , the scanning signal Vscan is OFF (at a low level), the first switching element TrT1for touch in each drive electrode COML illustrated inFIG.27is turned OFF (closed), and the second switching element TrT2for touch therein is turned ON (opened). Due to this, the display drive signal Vcomdc is supplied to each drive electrode COML via the conductive wire52B.

In the touch period Pt1, the gate line GCLT(n) for touch in the n-th row is selected, and the scanning signal Vscan(n) is turned ON (high level). The first switching element TrT1for touch of a drive electrode block COMLA(n) in the n-th row is turned ON (opened), and the second switching element TrT2for touch thereof is turned OFF (closed). Due to this, the touch drive signal Vcomac is supplied to each drive electrode COML in the drive electrode block COMLA(n) via the conductive wire52A. Based on the principle of mutual capacitance touch detection, the touch detection signal Vdet1is output from the touch detection electrode TDL (refer toFIG.13) to the touch detection unit40(refer toFIG.1). In the touch period Pt1, the scanning signal Vscan is OFF (low level) in the gate lines GCLT for touch other than the gate line GCLT(n) for touch, and the display drive signal Vcomdc is supplied to each drive electrode COML via the conductive wire52B.

In the touch period Pt2, a gate line GCLT(n+1) for touch in the (n+1)-th row is selected, and a scanning signal Vscan(n+1) is turned ON (high level). The first switching element TrT1for touch of a drive electrode block COMLA(n+1) in the (n+1)-th row is turned ON (opened), and the second switching element TrT2for touch thereof is turned OFF (closed). Due to this, the touch drive signal Vcomac is supplied to each drive electrode COML in the drive electrode block COMLA(n+1) via the conductive wire52A.

In the touch period Pt3, a gate line GCLT(n+2) for touch in the (n+2)-th row is selected, and a scanning signal Vscan(n+2) is turned ON (high level). The first switching element TrT1for touch of a drive electrode block COMLA(n+2) in the (n+2)-th row is turned ON (opened), and the second switching element TrT2for touch thereof is turned OFF (closed). Due to this, the touch drive signal Vcomac is supplied to each drive electrode COML in the drive electrode block COMLA(n+2) via the conductive wire52A. These processes are sequentially repeated to perform a touch detection operation of the entire touch detection surface.

As described above, in the present embodiment, the touch drive signal Vcomac as a drive signal for touch detection is supplied to the drive electrode COML via the conductive wire52A. The display drive signal Vcomdc having a common potential for the pixel electrode22is supplied to the drive electrode COML via the conductive wire52B. Accordingly, by sequentially scanning the drive electrodes COML arranged in a matrix, contact or proximity of an external conductor can be detected based on the basic principle of mutual capacitance touch detection.

Each of the conductive wire52A and the conductive wire52B is arranged to be overlapped with the data line SGL for display, so that an opening area of the sub-pixel SPix can be prevented from being reduced as compared with a case in which each of the conductive wire52A and the conductive wire52B is arranged in the same layer as the data line SGL for display, or a case in which each of the conductive wire52A and the conductive wire52B is arranged at a position different from that of the data line SGL for display. InFIGS.27and28, employed is a configuration in which two wires including the conductive wire52A and the conductive wire52B are arranged for the drive electrode COML in each column. Alternatively, a configuration in which three or more conductive wires are arranged along the pixel electrode22in each column may be employed. In this case, conductive wires other than the conductive wire52A and the conductive wire52B are arranged as dummy wires that are overlapped with the data line SGL for display and are not electrically coupled to the drive electrode COML. When the conductive wires are arranged along the pixel electrode22in each column, variation in arrangement pitch of the conductive wires can be suppressed, so that visibility can be improved.

The first switching element TrT1for touch and the second switching element TrT2for touch are switched to be coupled to or disconnected from the drive electrode COML in opposite phases for the same scanning signal. Due to this, the touch drive signal Vcomac and the display drive signal Vcomdc can be securely supplied. A switch unit for switching between supply of the touch drive signal Vcomac and supply of the display drive signal Vcomdc is not required to be arranged in the frame region10b, so that the frame can be narrowed.

FIG.31is a plan view illustrating a configuration example of the gate driver according to the third embodiment. As illustrated inFIG.31, the gate driver12includes the gate driver12C for touch and a gate driver12D for display. The gate driver12C for touch scans the gate line GCLT for touch and supplies the scanning signal to a selected gate line GCLT for touch. The gate driver12D for display scans the gate line GCL for display and supplies the scanning signal to a selected gate line GCL for display. In this way, a configuration in which the gate driver12C for touch and the gate driver12D for display are arranged can also be employed.

FIG.32is a plan view illustrating another configuration example of the gate driver according to the third embodiment. As illustrated inFIG.32, the gate line GCLT for touch and the gate line GCL for display are coupled to one gate driver12. The gate lines GCL for display are coupled to the shift registers SR<n>, SR<n+1>, SR<n+3>, SR<n+4>, and SR<n+5> of the gate driver12, and the gate line GCLT for touch is coupled to the shift register SR<n+2>. In addition to the conductive wire52A and the conductive wire52B, a conductive wire52C is arranged to be overlapped with the data line SGL for display. A clock signal CLK generated in a clock signal generation unit18is supplied to the gate driver12via the conductive wire52C.

The gate driver12sequentially scans the gate line GCLT for touch and the gate line GCL for display based on the clock signal CLK. The gate driver12supplies the scanning signal Vscan to the gate line GCLT for touch or the gate line GCL for display that is selected based on the clock signal CLK. The clock signal generation unit18is included in the control unit11(refer toFIG.1), and mounted on the display control IC19.

In this way, the conductive wire52C is arranged in the display region10aand used as a wire for supplying the clock signal CLK, so that the number of wires arranged in the frame region10bcan be reduced and the frame can be narrowed.

FIG.33is a plan view illustrating a light shielding part of the display device with a touch detection function according to a modification of the third embodiment.FIG.34is a cross-sectional view along the line XXXIV-XXXIV′ inFIG.33.

In the present modification, a light shielding part38is arranged above the gate line GCL for display and the data line SGL for display (refer toFIG.31). As illustrated inFIG.33, the light shielding part38includes a first light shielding part38aextending in the row direction and a second light shielding part38bextending in a direction intersecting with an extending direction of the first light shielding part38a, and the first light shielding part38aand the second light shielding part38bare arranged in a gridlike fashion. The first light shielding part38aoverlaps with the gate line GCL for display, and the second light shielding part38boverlaps with the data line SGL for display. A region surrounded by the first light shielding part38aand the second light shielding part38bis an opening region39.

As illustrated inFIG.34, the light shielding part38is arranged on a surface of the TFT substrate21side of the glass substrate31. The light shielding part38is arranged in the same layer as the color filter32. The color filter32is arranged at a position corresponding to the opening region39illustrated inFIG.33while being overlapped with the pixel electrode22. With the light shielding part38, the gate line GCL for display, the data line SGL for display, the switching element TrD for display, the first switching element TrT1for touch, and the second switching element TrT2for touch can be prevented from being visually recognized.

As illustrated inFIG.34, an orientation film33is arranged between the liquid crystal layer6, and the light shielding part38and the color filter32. An orientation film34is arranged between the pixel electrode22on the TFT substrate21side and the liquid crystal layer6. A spacer26is arranged between the TFT substrate21and the glass substrate31to keep a gap between the TFT substrate21and the glass substrate31. As illustrated inFIG.33, the spacer26is arranged in the vicinity of an intersecting part38X of the first light shielding part38aand the second light shielding part38bin a plan view.

In the present modification, the intersecting part38X overlapped with the spacer26has, for example, a circular shape in a plan view, and has a larger area than that of an intersecting part not overlapped with the spacer26between the first light shielding part38aand the second light shielding part38b. The first switching element TrT1for touch and the second switching element TrT2for touch are arranged to be overlapped with the spacers26and26, respectively, in a plan view. Thus, the first switching element TrT1for touch and the second switching element TrT2for touch are arranged to be overlapped with the intersecting part38X, so that the first switching element TrT1for touch and the second switching element TrT2for touch can be prevented from being visually recognized from the outside. The first switching element TrT1for touch and the second switching element TrT2for touch are arranged by utilizing a region in which the spacers26and26are arranged, so that an area of the opening region39can be prevented from being reduced.

Fourth Embodiment

FIG.35is a plan view illustrating a configuration example of the drive electrode and the drive electrode driver according to a fourth embodiment.FIG.36is a cross-sectional view illustrating a coupling point between the drive electrode and the conductive wire.

The present embodiment is different from the third embodiment in that the first switching element TrT1for touch and the second switching element TrT2for touch are not arranged in the drive electrode COML. As illustrated inFIG.35, a conductive wire53A is coupled to each drive electrode COML in the drive electrode block COMLA(n) in the n-th row. A conductive wire53B is coupled to each drive electrode COML in the drive electrode block COMLA(n+1) in the (n+1)-th row. A conductive wire53C is coupled to each drive electrode COML in the drive electrode block COMLA(n+2) in the (n+2)-th row.

As illustrated inFIG.36, the insulating layer58eis arranged between the conductive wire53A and the drive electrode COML. The conductive wire53A is electrically coupled to the drive electrode COML via a contact hole H7arranged in the insulating layer58e. The conductive wires53B and53C (not illustrated inFIG.36) are also electrically coupled to the drive electrode COML. The switching element TrD for display has the same configuration as that described above, but is not electrically coupled to the conductive wires53A,53B, and53C.

Each of the conductive wires53A,53B, and53C extends while overlapping with the data line SGL for display (refer toFIG.31), and is coupled to the drive electrode driver14. The drive electrode driver14includes the drive signal generation unit14A, a drive electrode scanning unit14B, the wires LAC and LDC, and switches SW1and xSW1. A plurality of conductive wires53A are coupled to one set of the switches SW1and xSW1, and a plurality of conductive wires53B and a plurality of conductive wires53C are also coupled to the different switches SW1and xSW1.

As illustrated inFIG.35, the switch SW1and the switch xSW1are switched to be ON and OFF in opposite phases. The switches SW1and xSW1are sequentially selected by the drive electrode scanning unit14B, and the scanning signal is supplied to the selected set of switches SW1and xSW1. When the scanning signal is supplied to the switches SW1and xSW1from the drive electrode scanning unit14B, the switch SW1is turned OFF and the switch xSW1is turned ON. When the scanning signal is not supplied, the switch SW1is turned ON, and the switch xSW1is turned OFF.

Each of the switches SW1is coupled to the wire LDC, and receives the display drive signal Vcomdc supplied from the drive signal generation unit14A. Each of the switches xSW1is coupled to the wire LAC, and receives the touch drive signal Vcomac supplied from the drive signal generation unit14A. When the scanning signal is supplied to one set of switches SW1and xSW1coupled to the conductive wire53A, the switch xSW1is turned ON, and the touch drive signal Vcomac is supplied to the drive electrode COML in the drive electrode block COMLA(n) via the conductive wire53A. When the drive electrode scanning unit14B sequentially scans the switches SW1and xSW1, the touch drive signal Vcomac is sequentially supplied to the drive electrode blocks COMLA(n+1) and COMLA(n+2) via the conductive wires53B and53C. Thus, touch detection is performed based on the principle of mutual capacitance touch detection described above.

When the switches SW1and xSW1are not selected by the drive electrode scanning unit14B, the switch SW1is turned ON, and the display drive signal Vcomdc is supplied to each drive electrode COML via the conductive wires53A,53B, and53C.

With such a configuration, by sequentially scanning the drive electrodes COML arranged in a matrix, contact or proximity of an external conductor can be detected based on the basic principle of mutual capacitance touch detection. In the present embodiment, each of the conductive wires53A,53B, and53C is coupled to each drive electrode COML, so that the number of wires within the display region10acan be reduced as compared with the third embodiment.

Fifth Embodiment

FIG.37is a plan view of the drive electrode and a drive circuit according to a fifth embodiment. The configuration of the drive electrode COML, the gate line GCLT for touch, the conductive wires52A and52B, the first switching element TrT1for touch, the second switching element TrT2for touch, and the gate driver12according to the present embodiment is similar to the configuration illustrated inFIG.27. The display device with a touch detection function according to the present embodiment detects contact or proximity of an external conductor based on self capacitance of the drive electrode COML.

As illustrated inFIG.37, the drive signal generation unit14A supplies the touch drive signal Vcomac to the conductive wire52A. The touch drive signal Vcomac is supplied to the drive electrode COML via the conductive wire52A and the first switching element TrT1for touch. Accordingly, based on the principle of self capacitance touch detection described above, a detection signal corresponding to the self capacitance of the drive electrode COML is output to the touch detection unit40via the conductive wire52A, and the touch detection signal Vdet2is output.

The drive signal generation unit14A supplies the display drive signal Vcomdc to the wire LDC, and supplies a signal Vsg1to wire LGC. The conductive wire52B is coupled to the wire LDC via the switch SW1, and coupled to the wire LGC via the switch xSW1. The switch SW1is coupled to a wire LS1, and the switch xSW1is coupled to a wire LS2. The switch SW1and the switch xSW1are switched between ON and OFF based on switch signals supplied from the wire LS1and the wire LS2, respectively. The switch signals supplied from the wire LS1and the wire LS2are in opposite phases, controlling the switch SW1and the switch xSW1to be ON and OFF in an opposite manner.

When the second switching element TrT2for touch is in an ON state and the switch SW1is turned ON, the display drive signal Vcomdc is supplied to the drive electrode COML via the conductive wire52B. When the second switching element TrT2for touch is in the ON state and the switch xSW1is turned ON, the signal Vsg1is supplied to the drive electrode COML via the conductive wire52B. The signal Vsg1preferably has the same waveform synchronized with the touch drive signal Vcomac.

With such a configuration, the display drive signal Vcomdc is supplied to the drive electrode COML in a display operation. When touch detection is performed, the touch drive signal Vcomac is supplied to the drive electrode COML selected as a detection target, and the signal Vsg1is supplied to the drive electrode COML that is not selected. When the signal Vsg1is supplied, parasitic capacitance between the drive electrode COML selected as a detection target and the non-selected drive electrode COML is reduced, so that a detection error and deterioration in detection sensitivity can be prevented.

FIG.38is a timing waveform chart illustrating an operation example of the display device with a touch detection function according to the fifth embodiment. As described above, in the display periods Pt1, Pt2. . . , the scanning signal Vscan is not supplied to the gate line GCLT for touch illustrated inFIG.37, the first switching element TrT1for touch is turned OFF, and the second switching element TrT2for touch is turned ON. Then the switch SW1is turned ON, and the switch xSW1is turned OFF. Accordingly, in each of the display periods Pt1, Pt2. . . , the display drive signal Vcomdc is supplied to the drive electrode COML.

In the touch period Pt1, the gate line GCLT(n) for touch in the n-th row is selected by the gate driver12, and the scanning signal Vscan(n) is supplied thereto. The first switching element TrT1for touch coupled to the gate line GCLT(n) for touch is turned ON, and the second switching element TrT2for touch is turned OFF. The touch drive signal Vcomac is supplied to each of the drive electrodes COML in the drive electrode block COMLA(n) in the n-th row via the conductive wire52A. Each drive electrode COML in the drive electrode block COMLA(n) outputs a detection signal corresponding to self capacitance thereof to the touch detection unit40via the conductive wire52A.

In the touch period Pt1, the first switching element TrT1for touch coupled to the non-selected gate lines GCLT(n+1) and GCLT(n+2) for touch is turned OFF, and the second switching element TrT2for touch coupled thereto is turned ON. Operations of the switches SW1and xSW1are reversed from the state in the display period Pt1, that is, the switch SW1is turned OFF and the switch xSW1is turned ON. Accordingly, the signal Vsg1is supplied to the drive electrode blocks COMLA(n+1) and COMLA(n+2) that are not selected as a detection target.

In the touch period Pt2, the gate line GCLT(n+1) for touch in the (n+1)-th row is selected by the gate driver12, and the touch drive signal Vcomac is supplied to each of the drive electrodes COML in the drive electrode block COMLA(n+1) in the (n+1)-th row via the conductive wire52A. The signal Vsg1is supplied to the drive electrode blocks COMLA(n) and COMLA(n+2) that are not selected as a detection target.

In the touch period Pt3, the gate line GCLT(n+2) for touch in the (n+2)-th row is selected by the gate driver12, and the touch drive signal Vcomac is supplied to each of the drive electrodes COML in the drive electrode block COMLA(n+2) in the (n+2)-th row via the conductive wire52A. The signal Vsg1is supplied to the drive electrode blocks COMLA(n) and COMLA(n+1) that are not selected as a detection target.

In this way, by sequentially selecting the drive electrode block COMLA to be a detection target in the touch periods Pt1and Pt2. . . , a self capacitance touch detection operation is performed on the entire touch detection surface.

According to the present embodiment, by arranging the conductive wires52A and52B coupled to the switching element for touch, the touch drive signal Vcomac, the display drive signal Vcomdc, and the signal Vsg1can be supplied to the drive electrode COML. The number of wires can be reduced as compared with a case in which each of wire is coupled to each of the drive electrodes COML.

In the touch periods Pt1and Pt2. . . using a self capacitance system, the signal Vsg1may be supplied to the gate line GCL for display and the data line SGL for display (not illustrated inFIG.37). The gate line GCL for display and the data line SGL for display may be in a floating state in which a fixed electric potential is not supplied. Accordingly, parasitic capacitance between the drive electrode COML and the gate line GCL for display, and parasitic capacitance between the drive electrode COML and the data line SGL for display can be reduced.

FIG.39is a plan view illustrating a configuration example of the drive electrode and the conductive wire according to a modification of the fifth embodiment. The drive electrode block COMLA inFIG.37includes a row of drive electrodes COML arranged in the row direction, but the embodiment is not limited thereto. As illustrated inFIG.39, the gate line GCLT for touch coupled to the gate driver12extends while being overlapped with a row of drive electrodes COML. The gate line GCLT for touch is bent on an opposite side of the gate driver12with the drive electrode COML interposed therebetween, and extends while being overlapped with the next row of drive electrodes COML. In this way, two rows of drive electrodes COML may be coupled to one gate line GCLT for touch, and the drive electrode block COMLA may include two rows of drive electrodes COML.

Two conductive wires52A and52A and two conductive wires52B and52B are coupled to a plurality of drive electrodes COML arranged in the column direction. The conductive wire52A is coupled to one drive electrode COML for one drive electrode block COMLA. The conductive wire52B is coupled to one drive electrode COML for one drive electrode block COMLA. That is, the drive electrodes COML and COML adjacent to each other in the column direction within the drive electrode block COMLA are coupled to different conductive wires52A and52A and conductive wires52B and52B.

The touch drive signal Vcomac is supplied to each drive electrode COML from the drive signal generation unit14A via the conductive wire52A. The drive electrode COML then supplies the output signal to the touch detection unit40via the conductive wire52A. The wire LDC is coupled to each conductive wire52B via the switch SW1, and the wire LGC is coupled thereto via the switch xSW1. Accordingly, the display drive signal Vcomdc and the signal Vsg1are supplied to the conductive wire52B. Thus, similarly to the operation example illustrated inFIG.38, in the touch periods Pt1and Pt2. . . , self capacitance touch detection can be performed by sequentially scanning the drive electrode blocks COMLA(n), COMLA(n+1), and COMLA(n+2).

In the present embodiment, touch detection can be performed for the detection electrode block COMLA including two rows of drive electrodes COML in one touch period, so that detection time for the entire touch detection surface can be reduced. In the present embodiment, the drive electrode COML has a rectangular shape obtained by dividing the drive electrode COML having a square shape illustrated inFIG.37, for example, into two parts including an upper part and a lower part. Alternatively, the drive electrode COML having a square shape illustrated inFIG.37, for example, can naturally be employed.

Sixth Embodiment

FIG.40is a block diagram illustrating a configuration example of the display device with a touch detection function according to a sixth embodiment. A display device1A with a touch detection function according to the present embodiment can switch between mutual capacitance touch detection and self capacitance touch detection to be performed. As illustrated inFIG.40, the touch detection unit40includes a touch detection signal amplification unit42A to which the touch detection signal Vdet1using a mutual capacitance system is supplied, an A/D conversion unit43A, a signal processing unit44A, and a coordinate extracting unit45A. The touch detection unit40further includes a touch detection signal amplification unit42B to which the touch detection signal Vdet2using a self capacitance system is supplied, an A/D conversion unit43B, a signal processing unit44B, and a coordinate extracting unit45B. The mutual capacitance touch detection and the self capacitance touch detection can be switched based on the control signal of the control unit11.

FIG.41is a plan view of the drive electrode and the drive circuit according to the sixth embodiment.FIG.42is a timing waveform chart illustrating an operation example of the display device with a touch detection function according to the sixth embodiment. The configuration of the drive electrode COML, the gate line GCLT for touch, the conductive wires52A and52B, the first switching element TrT1for touch, the second switching element TrT2for touch, and the gate driver12according to the present embodiment is similar to that illustrated inFIG.27.

As illustrated inFIG.41, the touch drive signal Vcomac is supplied to the conductive wire52A via the wire LAC. The switch SW2is coupled to the conductive wire52A, and the switch SW2is switched between ON and OFF based on a switch signal supplied from wire LS3. In a state in which the switch SW2is ON, self capacitance touch detection is performed, and the touch detection signal Vdet2is output to the touch detection unit40via the conductive wire52A and the switch SW2. The wire LDC is coupled to the conductive wire52B via the switch SW1, and the wire LGC is coupled thereto via the switch xSW1. In a state in which the switch SW1is ON and the switch xSW1is OFF, the display drive signal Vcomdc is supplied to the conductive wire52B. In a state in which the switch SW1is OFF and the switch xSW1is ON, the signal Vsg1is supplied to the conductive wire52B.

The left figure ofFIG.42is a timing waveform chart of self capacitance touch detection, and the right figure ofFIG.42is a timing waveform chart of mutual capacitance touch detection. As illustrated in the left figure ofFIG.42, a self capacitance touch detection operation is performed similarly toFIG.38. The touch drive signal Vcomac is sequentially supplied to the selected drive electrode block COMLA. In the touch periods Pt1and Pt2. . . and display periods Pd1and Pd2. . . using a self capacitance system, the switch SW2is in the ON state, and the touch detection signal Vdet2is output to the touch detection unit40via the conductive wire52A.

The switches SW1and xSW1are switched to be ON and OFF between the touch periods Pt1and Pt2. . . and the display periods Pd1and Pd2. . . using a self capacitance system. In the display periods Pd1and Pd2. . . , the switch SW1is turned ON, the switch xSW1is turned OFF, and the display drive signal Vcomdc is supplied to the drive electrode blocks COMLA(n), COMLA(n+1), and COMLA(n+2). In the touch periods Pt1and Pt2. . . , the switch SW1is turned OFF, the switch xSW1is turned ON, and the signal Vsg1is supplied to the drive electrode block COMLA that is not selected by the gate driver12.

Next, when the control unit11(refer toFIG.40) switches self capacitance touch detection to mutual capacitance touch detection, an operation illustrated in the right figure ofFIG.42is performed. As illustrated in the right figure ofFIG.42, a mutual capacitance touch detection operation according to the present embodiment is performed similarly toFIG.30. That is, in touch periods Ptm1, Ptm2. . . using a mutual capacitance system, the touch drive signal Vcomac is sequentially supplied to the selected drive electrode block COMLA. In the mutual capacitance touch detection operation, the switch SW2is turned OFF, the touch detection signal Vdet2is not output from the conductive wire52A, and the touch detection signal Vdet1is output from the touch detection electrode TDL.

In the touch periods Ptm1, Ptm2. . . and the display periods Pd1and Pd2. . . using a mutual capacitance system, the switch SW1is turned ON, and the switch xSW1is turned OFF. Due to this, the signal Vsg1is not supplied to the conductive wire52B, and the display drive signal Vcomdc is supplied to the non-selected drive electrode block COMLA.

As described above, the display device1A with a touch detection function according to the present embodiment can switch between self capacitance touch detection and mutual capacitance touch detection with a configuration in which the conductive wires52A and52B are coupled to the drive electrode COML. Due to this, a detection system can be appropriately switched to improve detection accuracy in accordance with different input operation methods and the external environment.

In the present embodiment, the same touch drive signal Vcomac is supplied to the conductive wire52A in both of self capacitance touch detection and mutual capacitance touch detection. Alternatively, a touch drive signal having different amplitude and a different frequency may be supplied. In the touch periods Ptm1, Ptm2. . . using a mutual capacitance system, the display drive signal Vcomdc is supplied to the non-selected drive electrode block COMLA. Alternatively, a floating state may be caused in which the voltage signal is not supplied to the non-selected drive electrode block COMLA and electric potential is not fixed. In this case, a configuration may be employed in which the display drive signal Vcomdc is not supplied to the wire LDC in the touch periods Ptm1, Ptm2. . . , or a configuration may be employed in which a switch is added between the wire LDC and the conductive wire52B to disconnect the wire LDC from the conductive wire52B in the touch periods Ptm1, Ptm2. . . .

The preferred embodiments of the present invention have been described above. However, the present invention is not limited thereto. Content disclosed in the embodiments is merely an example, and various modifications can be made without departing from the gist of the invention. The present invention naturally encompasses an appropriate modification maintaining the gist of the invention.

For example, the shapes of the drive electrode COML, the touch detection electrode TDL, and the pixel electrode22are merely an example, and may be variously modified. The number of conductive wires, the arrangement thereof, the shape thereof, and the like may be appropriately modified. The embodiments may be appropriately combined. For example, the conductive wire may be coupled to the gate line GCLT for touch illustrated inFIG.27similarly to the first embodiment to supply the scanning signal via the conductive wire.