KR20070062691A - Display device - Google Patents

Abstract

A display device is provided to increase aperture ratio and suppress distortion of a sensing data signal by transmitting a sensing signal through an image data line and thereby not requiring an additional sensing data line. A plurality of image data lines(D1~Dm) transmits image data signals to corresponding pixels and a plurality of image scan lines transmits image scan signals to corresponding pixels. A plurality of sensing data lines(SY1~SYN) is connected to a plurality of first sensing units(SU) and transmits a first sensing data signal. A plurality of first sensing signal output units(SOUT) is connected to the sensing data lines. The second sensing units are connected to at least one of the image data lines to transmit a second sensing data signal. At least one of second sensing signal output units generates one output signal on the basis of the second sensing data signal.

Description

Display device {DISPLAY DEVICE}

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention, which is a block diagram of the liquid crystal display shown in terms of a pixel.

2 is an equivalent circuit diagram of one pixel of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention, and is a block diagram of the liquid crystal display shown in terms of a sensing unit.

4 is an equivalent circuit diagram of a sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention.

5 is a circuit diagram of a sensing signal output unit connected to one sensing data line in a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 6 is a driving timing diagram for driving the sense signal output unit and the reset transistor shown in FIG. 5.

7 is a block diagram of a liquid crystal display according to another exemplary embodiment of the present invention, and is a block diagram of the liquid crystal display shown in terms of a detector.

8 is an equivalent circuit diagram of one sensing unit of a liquid crystal display according to another exemplary embodiment of the present invention.

9 is a circuit diagram of an example of a sensing signal output unit connected to one image data line in a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 10 is a driving timing diagram of the sensing signal output unit shown in FIG. 9.

FIG. 11 is a circuit diagram of another example of a sensing signal output unit connected to one image data line in a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 12 is a driving timing diagram of the sensing signal output unit illustrated in FIG. 11.

The present invention relates to a display device.

Typical liquid crystal displays (LCDs) among display devices include two display panels provided with pixel electrodes and a common electrode, and a liquid crystal layer having dielectric anisotropy interposed therebetween. The pixel electrodes are arranged in a matrix and connected to switching elements such as thin film transistors (TFTs) to receive data voltages one by one in sequence. The common electrode is formed over the entire surface of the display panel and receives a common voltage. The pixel electrode, the common electrode, and the liquid crystal layer therebetween form a liquid crystal capacitor, and the liquid crystal capacitor becomes a basic unit that forms a pixel together with a switching element connected thereto.

In such a liquid crystal display, a voltage is applied to two electrodes to generate an electric field in the liquid crystal layer, and the intensity of the electric field is adjusted to control the transmittance of light passing through the liquid crystal layer to obtain a desired image.

A touch screen panel is a device that touches a finger or a touch pen (stylus) on the screen to write and draw letters or pictures, or execute icons to perform a desired command on a machine such as a computer. . A liquid crystal display with a touch screen panel may find out whether a user's finger or a touch pen touches the screen and contact position information. However, such a liquid crystal display device has problems such as a cost increase due to a touch screen panel, a decrease in yield due to a process of adhering the touch screen panel to a liquid crystal display panel, a decrease in luminance of the liquid crystal panel, and an increase in product thickness.

Therefore, in order to solve these problems, a technology for embedding a sensing element made of a thin film transistor instead of a touch screen panel inside a pixel displaying an image in a liquid crystal display device has been developed. The sensing element detects a change in light applied to the screen by a user's finger or the like so that the liquid crystal display may determine whether the user's finger or the like has touched the screen and the contact position information.

However, since the sensing element and the wiring for the same occupy a large area, the aperture ratio of the liquid crystal display is reduced, and the structure and manufacturing cost are increased.

Accordingly, the technical problem to be achieved by the present invention is to simplify the structure of the display device due to the sensing element and to reduce the aperture ratio.

Another technical problem to be achieved by the present invention is to reduce the manufacturing cost caused by the wiring for the sensing element.

According to an embodiment of the present invention, a display device includes a plurality of pixels, a plurality of image data lines for transmitting the image data signals to the pixels, and a plurality of images for transmitting image scanning signals to the pixels. A plurality of sensing data lines connected to a scan line, a plurality of first sensing units, a plurality of second sensing units, and a plurality of first sensing units, for transmitting a first sensing data signal, and connected to the sensing data lines And a plurality of first sensing signal output units generating one output signal based on the first sensing data signal, wherein the plurality of second sensing units are connected to at least one of the plurality of image data lines, The at least one image data line transmits a second sensed data signal, and generates one output signal based on the second sensed data signal. Even further it includes a second sensing signal output parts.

And a common electrode facing the image data line and to which a constant voltage is applied, wherein each of the first sensing units includes a reference capacitor having a constant capacitance and a variable capacitor formed between the at least one image data line and the common electrode. Good to do.

The reference capacitor may be a parasitic capacitor formed in a pixel connected to the at least one image data line.

And a reference voltage line formed on a layer different from the image data line and receiving a constant voltage, wherein the reference capacitor may be a capacitor formed between the reference voltage line and the at least one data line.

The reference voltage line may be formed of the same material as the image scan line.

The image data line may transfer a voltage of a predetermined level in the porch section.

The first sensing signal output unit may include a first transistor connected to an input terminal, a first control signal connected to a control terminal, and an output terminal connected to an output terminal of the sensing signal output unit, to an output terminal of the first transistor. A second transistor having an input terminal connected, an output terminal connected to a second driving voltage, a sensing signal data line connected to a control terminal, an input terminal connected to the second driving voltage, and a second control signal connected to a control terminal; The third transistor may include an output terminal connected to the sensing signal data line.

The second sensing signal output unit may include a first transistor connected to an input terminal, a first control signal connected to a control terminal, and an output terminal connected to the sensing signal output unit, an output terminal of the first transistor. A second transistor having an input terminal connected, an output terminal connected to a second driving voltage, and at least one image data line connected to a control terminal; and an input terminal connected to the second driving voltage and a second control signal connected to a control terminal. And a third transistor having an output terminal connected to the at least one image data line.

The second sensing signal output unit may include: a first transistor connected to an input terminal, a first control signal connected to a control terminal, and an output terminal connected to the sensing signal output unit; an output terminal of the first transistor A second transistor having an input terminal connected thereto and an output terminal connected to a second driving voltage; a third transistor having an input terminal connected to the second driving voltage and a second control signal connected to a control terminal; And a fourth transistor having an input terminal connected thereto, a control terminal connected to the third control signal, and an output terminal connected to the control terminal of the second transistor and the output terminal of the third transistor.

The fourth transistor is preferably turned on during the porch period.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

A liquid crystal display, which is one embodiment of the display device of the present invention, will now be described in detail with reference to FIGS. 1 to 4.

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention, which is a block diagram of a liquid crystal display according to a pixel, and FIG. 2 is a pixel of the liquid crystal display according to the exemplary embodiment of the present invention. Equivalent circuit diagram. 3 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention, which is a block diagram of the liquid crystal display according to a sensing unit, and FIG. 4 is a sensing diagram of the liquid crystal display according to the exemplary embodiment of the present invention. Equivalent circuit diagram for negative.

1 and 3, a liquid crystal display according to an exemplary embodiment of the present invention may include a liquid crystal panel assembly 300, an image scanning unit 400, an image data driver 500, and a liquid crystal panel assembly 300 connected thereto. A sensing signal processor 800, a gray voltage generator 550 connected to the image data driver 500, a contact determiner 700 connected to the sensing signal processor 800, and a signal controller 600 for controlling them. .

1 to 4, the liquid crystal panel assembly 300 includes a plurality of display signal lines G ₁ -G _n , D ₁ -D _m and a plurality of pixels PX connected thereto and arranged in a substantially matrix form. ), and a plurality of sensing signal lines _{(SY 1 -SY N, SX 1} -SX M, RL) and is connected thereto, and a plurality are arranged in the form of a substantially matrix sensor (SU), a plurality of reset transistors (Qr), each of the sensing signal _{(SY 1 -SY N, SX 1} -SX M) a plurality of sensing signal output (SOUT), and each of the sensing signal output part output a plurality of data lines (OY ₁ -OY _N connected to the (SOUT) are connected to , OX ₁ -OX _M ).

2, the liquid crystal panel assembly 300 includes a thin film transistor array panel 100 and a common electrode panel 200 facing each other, a liquid crystal layer 3 interposed therebetween, and two display panels 100 and 200. Gaps (not shown) that form a gap between them and are somewhat deformed.

The display signal lines G ₁ -G _n and D ₁ -D _m are a plurality of image scanning lines G ₁ -G _n for transmitting an image scanning signal and an image data line D ₁ -D _m for transmitting an image data signal. sensing a signal line, comprising a _{(SY 1 -SY N, SX 1} -SX M, RL) includes a plurality of horizontal sensing data lines for transmitting the detected data signal (SY ₁ -SY _N) and a plurality of vertical sensing data line (SX ₁ -SX _M ) and a plurality of reference voltage lines RL for transmitting a reference voltage. The reference voltage line RL may be omitted as necessary.

The image scanning lines G ₁ -G _n and the horizontal sensing data lines SY ₁ -SY _N extend substantially in the row direction and are substantially parallel to each other, and the image data lines D ₁ -D _m and the vertical sensing data lines ( SX ₁ -SX _M ) extend in approximately the column direction and are substantially parallel to each other. The reference voltage line RL extends in the row or column direction.

Each pixel PX includes a switching element Q connected to the display signal lines G ₁ -G _n , D ₁ -D _m , a liquid crystal capacitor Clc, and a storage capacitor Cst connected thereto. ). Holding capacitor Cst can be omitted as needed.

The switching element Q is a three-terminal element such as a thin film transistor provided in the thin film transistor array panel 100, the control terminal of which is connected to the image scanning line G ₁ -G _n , and the input terminal of the thin film transistor display panel 100. D ₁ -D _m ), and the output terminal is connected to the liquid crystal capacitor Clc and the storage capacitor Cst. In this case, the thin film transistor includes amorphous silicon or poly crystalline silicon.

The liquid crystal capacitor Clc has two terminals, the pixel electrode 191 of the thin film transistor array panel 100 and the common electrode 270 of the common electrode display panel 200, and the liquid crystal layer 3 between the two electrodes 191 and 270. Functions as a dielectric. The pixel electrode 191 is connected to the switching element Q, and the common electrode 270 is formed on the entire surface of the common electrode display panel 200 and receives the common voltage Vcom. Unlike in FIG. 2, the common electrode 270 may be provided in the thin film transistor array panel 100. In this case, at least one of the two electrodes 191 and 270 may be linear or rod-shaped.

The storage capacitor Cst, which serves as an auxiliary role of the liquid crystal capacitor Clc, is formed by overlapping a separate signal line (not shown) and the pixel electrode 191 provided in the thin film transistor array panel 100 with an insulator interposed therebetween. A predetermined voltage such as the common voltage Vcom is applied to this separate signal line. However, the storage capacitor Cst may be formed such that the pixel electrode 191 overlaps the front end image scanning line directly above the insulator.

On the other hand, in order to implement color display, each pixel PX uniquely displays one of the primary colors (spatial division) or each pixel PX alternately displays the primary colors over time (time division). The desired color is recognized by the spatial and temporal sum of these primary colors. Examples of the primary colors include three primary colors such as red, green, and blue. FIG. 2 shows that each pixel PX includes a color filter 230 representing one of the primary colors in an area of the common electrode display panel 200 corresponding to the pixel electrode 191 as an example of spatial division. . Unlike FIG. 2, the color filter 230 may be formed above or below the pixel electrode 191 of the thin film transistor array panel 100.

At least one polarizer (not shown) for polarizing light is attached to an outer surface of the liquid crystal panel assembly 300.

The sensing unit SU may have a structure shown in FIG. 4.

The sensing unit SU shown in FIG. 4 is provided between the variable capacitor Cv, the sensing data line SL, and the reference voltage line RL connected to the sensing data line (hereinafter, referred to as sensing data line) indicated by the reference numeral SL. It includes a reference capacitor (Cp) connected to.

The reference capacitor Cp is formed by overlapping the reference voltage line RL and the sensing data line SL of the thin film transistor array panel 100 with an insulator interposed therebetween.

The variable capacitor Cv has the sensing data line SL of the thin film transistor array panel 100 and the common electrode 270 of the common electrode display panel 200 as two terminals, and the liquid crystal layer 3 between the two terminals functions as a dielectric. do. The capacitance of the variable capacitor Cv is changed by an external stimulus such as a user's touch applied to the liquid crystal panel assembly 300. For example, pressure may be used as the external stimulus. When pressure is applied to the common electrode display panel 200, the distance between the two terminals is changed to change the capacitance of the variable capacitor Cv. When the capacitance changes, the magnitude of the contact voltage Vn between the reference capacitor Cp and the variable capacitor Cv changes, which depends on the magnitude of the capacitance. The contact voltage Vn flows on the sensing data line SL as a sensing data signal, and based on the contact voltage Vn, the contact voltage Vn may be determined. In this case, the reference capacitor Cp has a fixed capacitance, and the reference voltage applied to the reference capacitor Cp has a constant voltage value, so that the contact voltage Vn varies in a certain range. Therefore, the sensing data signal may always have a voltage range within a certain range, thereby easily determining whether or not the contact is made.

The sensing unit SU is disposed between two adjacent pixels PX. As illustrated in FIG. 3, the entire liquid crystal panel assembly 300 is arranged in a substantially matrix form, and is connected to horizontal and vertical sensing data lines SY ₁ -SY _N and SX ₁ -SX _M , respectively. The density of the pair of sensing units SU disposed adjacent to the area may be, for example, about 1/4 of the dot density. Here, one dot includes, for example, three pixels PX arranged side by side and displaying three primary colors such as red, green, and blue, displaying one color, and a basic unit representing the resolution of the liquid crystal display device. do. However, one dot may consist of four or more pixels PX, and in this case, each pixel PX may display one of three primary colors and white.

An example in which the density of the pair of sensing units SU is 1/4 of the dot density is one in which the horizontal and vertical resolutions of the pair of sensing units SU are 1/2 of the horizontal and vertical resolutions of the liquid crystal display device, respectively. Can be. In this case, there may be a pixel row and a pixel column without the sensing unit SU.

By matching the detection unit SU density and the dot density to such an extent, the liquid crystal display device may be applied to high precision applications such as character recognition. Of course, the resolution of the sensing unit SU may be higher or lower as necessary.

The reset transistor Qr1 is a three-terminal element such as a thin film transistor, the control terminal of which is connected to the reset control signal Vsw1, the input terminal of which is connected to the reset voltage Vst1, and the output terminal of the sensing data line. It is connected to (SL). The reset transistor Qr1 is positioned at an edge of the liquid crystal panel assembly 300 in which no pixel is disposed and supplies the reset voltage Vst1 to the sensing data line SL according to the reset control signal Vsw1.

The plurality of sensing signal output units SOUT have the same structure, and as illustrated in FIG. 5, each of the sensing signal output units SOUT includes the first and second output transistors Qs1 and Qs2 and the reset transistor Qr2. ). These transistors Qs1, Qs2, and Qr2 are also three-terminal elements such as thin film transistors.

The input terminal of the first output transistor Qs1 is connected to the input voltage Vst2, the control terminal is connected to the control signal Vsw2, and the output terminal is the corresponding output data line OX of the sensing signal processor 800. ₁ -OX _M ). The input terminal of the second output transistor Qs2 is connected to the output terminal of the first output transistor Qs1 and is connected to the corresponding output data line OX ₁ -OX _M of the sensing signal processing unit 800, and the control terminal is It is connected to the sense data line SL and the output terminal is connected to the driving voltage Vss. The input terminal of the reset transistor Qr2 is connected to the driving voltage Vss, the control terminal is connected to the reset control signal Vsw3, and the output terminal is connected to the sensing data line SL.

The sensing signal output unit SOUT is also positioned at the edge of the liquid crystal panel assembly 300 and generates an output signal based on the sensing data signal flowing through the sensing data line SL. An output current is mentioned as an output signal. Alternatively, the output transistors Qs1 and Qs2 may generate a voltage as an output signal.

The output data lines OY ₁ -OY _N and OX ₁ -OX _M are connected to the horizontal and vertical sensing data lines SY ₁ -SY _N and SX ₁ -SX _M , respectively, through corresponding sensing signal outputs SOUT. a plurality of horizontal and vertical output data lines, which comprises _{(OY 1 -OY N, OX 1} -OX M). The output data lines OY ₁ -OY _N and OX ₁ -OX _M are connected to the sensing signal processing unit 800 and transmit an output signal from the sensing signal output unit SOUT to the sensing signal processing unit 800. The horizontal and vertical output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) extend approximately in the column direction and are nearly parallel to each other.

Referring back to FIGS. 1 and 3, the gray voltage generator 550 generates two sets of gray voltage sets (or reference gray voltage sets) related to the transmittance of the pixel. One of the two sets has a positive value for the common voltage Vcom and the other set has a negative value.

The image scanning unit 400 is connected to the image scanning lines G ₁ -G _n of the liquid crystal panel assembly 300 to gate-on voltage Von for turning on the switching element Q, and gate-off voltage Voff for turning off. ) Is applied to the image scanning lines G ₁ -G _n .

The image data driver 500 is connected to the image data lines D ₁ -D _m of the liquid crystal panel assembly 300, and selects a gray voltage from the gray voltage generator 550 and uses the image data as the image data signal. Applies to lines D ₁ -D _m . However, when the gray voltage generator 550 provides only a predetermined number of reference gray voltages instead of providing all voltages for all grays, the image data driver 500 divides the reference gray voltages so that the grays for all grays are divided. Generates a voltage and selects an image data signal among them.

Detection signal processing section 800 is connected to the sensing of the liquid crystal panel assembly 300, a data line _{(SY 1 -SY N, SX 1} -SX M) detects the data line _{(SY 1 -SY N, SX 1} -SX M) to After receiving the sensed data signal output through the signal processing such as amplification, filtering and the like to analog-to-digital conversion to generate a digital sense signal (DSN).

The touch determining unit 700 receives the digital sensing signal DSN from the sensing signal processing unit 800, performs a predetermined calculation process, determines whether the contact is made, and the contact position, and then sends the contact information INF to the external device. The touch determination unit 700 may monitor an operation state of the sensing unit SU based on the digital sensing signal DSN and control signals applied to the sensing unit SU.

The signal controller 600 controls operations of the image scanning unit 400, the image data driver 500, the gray voltage generator 550, and the detection signal processor 800.

Each of the driving devices 400, 500, 550, 600, 700, and 800 may be mounted directly on the liquid crystal panel assembly 300 in the form of at least one integrated circuit chip, or may be a flexible printed circuit film. It may be mounted on the liquid crystal panel assembly 300 in the form of a tape carrier package (TCP) or mounted on a separate printed circuit board (not shown). Alternatively, these driving devices 400, 500, 550, 600, 700, and 800 are connected to signal lines G ₁ -G _n , D ₁ -D _m , SY ₁ -SY _N , SX ₁ -SX _M and thin film transistors ( Q) together with the liquid crystal panel assembly 300 may be integrated.

Next, the display operation and the detection operation of the liquid crystal display will be described in more detail.

Next, the display operation and the detection operation of the liquid crystal display will be described in more detail.

The signal controller 600 receives input image signals R, G, and B and an input control signal for controlling the display thereof from an external device (not shown). The input video signals R, G, and B contain luminance information of each pixel PX, and the luminance is a predetermined number, for example, 1024 (= 2 ¹⁰ ), 256 (= 2 ⁸ ), or 64 (= 2 ⁶ ) It has gray. Examples of the input control signal include a vertical sync signal Vsync, a horizontal sync signal Hsync, a main clock MCLK, and a data enable signal DE.

The signal controller 600 receives the input image signals R, G, and B based on the input image signals R, G, and B and the input control signal, and generates operating conditions of the liquid crystal panel assembly 300 and the image data driver 500. Process the image scan control signal CONT1, the image data control signal CONT2, the sensing data control signal CONT3, and the like, and then output the image scan control signal CONT1 to the image scan unit 400. The image data control signal CONT2 and the processed image signal DAT are sent to the image data driver 500, and the sensing data control signal CONT3 is sent to the detection signal processor 800.

The image scan control signal CONT1 includes a scan start signal STV indicating the start of scanning and at least one clock signal controlling the output of the gate-on voltage Von. The image scan control signal CONT1 may further include an output enable signal OE that defines a duration of the gate-on voltage Von.

The image data control signal CONT2 is a load signal for applying the image data signal to the horizontal synchronization start signal STH indicating the start of transmission of the image data DAT in one pixel row and the image data lines D ₁ -D _m . LOAD) and data clock signal HCLK. The image data control signal CONT2 is also an inversion signal for inverting the voltage polarity of the image data signal with respect to the common voltage Vcom (hereinafter referred to as the polarity of the image data signal by reducing the voltage polarity of the image data signal with respect to the common voltage). RVS) may be further included.

In response to the image data control signal CONT2 from the signal controller 600, the image data driver 500 receives the digital image signal DAT for the pixel PX of one pixel row, and each digital image signal DAT. ) by selecting a gray voltage corresponding to the converted digital video signal (DAT) to the analog image data signals, and then applies them to the corresponding image data lines (D ₁ -D _m).

The image scanning unit 400 applies the gate-on voltage Von to the image scanning line G ₁ -G _n in response to the image scanning control signal CONT1 from the signal controller 600, thereby applying the image scanning line G ₁ -G. _n ) turns on the switching element Q connected. Then, the image data signal applied to the image data lines D ₁ -D _m is applied to the pixel PX through the turned-on switching element Q.

The difference between the voltage of the image data signal applied to the pixel PX and the common voltage Vcom is shown as the charging voltage of the liquid crystal capacitor Clc, that is, the pixel voltage. The arrangement of the liquid crystal molecules varies according to the magnitude of the pixel voltage, thereby changing the polarization of light passing through the liquid crystal layer 3. The change in polarization is represented as a change in the transmittance of light by the polarizer attached to the liquid crystal panel assembly 300, and thus a desired image may be displayed.

This process is repeated in units of one horizontal period (also referred to as 1H "and equal to one period of the horizontal sync signal Hsync and the data enable signal DE), thereby repeating all image scanning lines G ₁ -G _n . The image data signal is applied to all the pixels PX by sequentially applying the gate-on voltage Von to display an image of one frame.

When one frame ends, the next frame starts and the state of the inversion signal RVS applied to the image data driver 500 is controlled so that the polarity of the image data signal applied to each pixel PX is opposite to that of the previous frame. ("Frame inversion"). In this case, the polarity of the image data signal flowing through one image data line is changed (eg, inversion of a row, inversion of a point) according to the characteristics of the inversion signal RVS within one frame, or the polarity of the image data signal applied to one pixel row. May differ from one another (eg, nirvana, point inversion).

The sensing signal processing unit 800 performs a porch section between a frame and a frame once per frame according to the sensing data control signal CONT3, more specifically, in a porch section between a display section of one frame and a display section of an adjacent frame. Read sense data signal applied through output data line (OY ₁ -OY _N , OX ₁ -OX _M ). In the porch section, since the sensing data signal is less affected by the driving signals from the image scanning unit 400, the image data driver 500, and the like, the reliability of the sensing data signal is increased. However, such a read operation is not necessarily performed every frame, but may be performed once every plurality of frames as necessary. In addition, more than one read operation may be performed in the porch section.

When the sensing signal processing unit 800 reads the sensing data signal, the sensing signal output unit SOUT outputs the sensing data signal from the sensing signal lines SY ₁ -SY _N and SX ₁ -SX _M. OY ₁ -OY _N , OX ₁ -OX _M ). The operation of the sensing signal output unit SOUT will be described with reference to FIG. 6.

FIG. 6 is a driving timing diagram for driving the sense signal output unit and the reset transistor shown in FIG. 5.

As illustrated in FIG. 6, the liquid crystal display according to the present exemplary embodiment performs a sensing operation in a porch section between a display section and a display section of a frame to which the data voltage Vd for image display is applied as described above. In the porch period, the image data lines D ₁ -D _m may maintain a high impedance state.

The control signals Vsw1 and Vsw3 have a turn-on voltage Ton for turning on the transistors Qr1, Qs1, and Qr2, respectively, and a turn-off voltage Toff for turning off the transistors. The turn-on voltage Ton may use the gate-on voltage Von and the turn-off voltage Toff may use the gate-off voltage Voff. The levels of the turn on voltage Ton and the turn off voltage Toff applied to each of the control signals Vsw1-Vsw3 may be the same or different from each other. The turn-on voltage Ton of the reset control signal Vsw1 has a high level and a low level, and may be applied when the common voltage Vcom swinging the high level and the low level every 1H is at the high level.

When the read operation of the sensing signal flowing through each sensing signal line SL is started, the turn-on voltage Ton is applied to the reset control signal Vsw1 to turn on the reset transistor Qr1. For this reason, the reset voltage Vst1 applied to the input terminal of the reset transistor Qr1 is applied to the sense data line SL to initialize the sense data line SL with the reset voltage Vst1.

As such, when the initialization operation of the sensing data line SL is completed, the sensing signal output unit SOUT outputs a sensing data signal output from the corresponding sensing line SL.

Therefore, the reset control signal Vsw1 changes from the turn-on voltage Ton to the turn-off voltage Toff, and the state of the control signal Vsw2 changes from the turn-off voltage Toff to the turn-on voltage Ton. As a result, the first output transistor Qs1 is turned on and the sensing data line SL is in a floating state so that the capacitance of the variable capacitor Cv and the common voltage (V) depending on whether the sensing unit SU is in contact with each other. The voltage applied to the control terminal of the output transistor Qs2 changes based on the variation in Vcom). As a result of the voltage change, an operating state of the second output transistor Qs2 is changed to change the current of the input voltage Vst2 flowing through the turned-on first output transistor Qs1 to output the data lines OY ₁ -OY _N and OX. _1- OX _M ) is output as the sense data signal.

Therefore, the sensing signal processor 800 reads a sensing signal applied through each sensing line SL. In this case, it is preferable to set the detection signal reading time within 1H after the reset control signal Vsw1 becomes the turn-off voltage Toff. That is, it is preferable to read the sensing signal before the common voltage Vcom becomes high again. This is because the sensing signal also changes as the level of the common voltage Vcom changes.

Since the sensing data signal is changed based on the reset voltage Vst1, the sensing data signal may always have a voltage range within a predetermined range, thereby easily determining whether or not the contact is made.

After the sensing signal processor 800 reads the sensing signal, the reset control signal Vsw3 becomes the turn-on voltage Ton to turn on the reset transistor Qr2. Then, the driving voltage Vss, which may be the ground voltage, is applied to the sensing data line SL to reset the sensing data line SL to the ground voltage. The driving voltage Vss is maintained until the reset voltage Vst1 is applied to the sensing data line SL. As a result, the second output transistor Qs2 is turned off until the next second reset voltage Vst2 is applied, thereby reducing power consumption due to unnecessary operation.

The turn-on voltage Ton of the reset control signal Vsw1 may be applied when the common voltage Vcom is at a low level. In this case, the sensing signal is read before the common voltage Vcom is changed to a high level and again becomes low. In addition, the reset control signal Vsw1 may be synchronized with an image scan signal applied to the last image scan line G _n .

The reset control signal Vsw2 may be the turn-on voltage Ton in the 1H section immediately after the sensing signal is read, or may be the turn-on voltage Ton in the 1H section thereafter.

As described above, the sensing signal processor 800 which reads the analog sensing data signal performs signal processing such as amplification using the amplifying unit (not shown), etc., and then converts the sensing data signal into a digital sensing signal DSN to make contact. Export to the determination unit 700.

The touch determination unit 700 receives a digital sensing signal DSN, performs appropriate arithmetic processing to find out whether a contact is made and a contact position, and transmits the same to an external device, and the external device transmits the image signals R, G, and B based thereon. Transfer to the liquid crystal display device.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described with reference to FIGS. 7 and 8.

FIG. 7 is a block diagram of a liquid crystal display according to another exemplary embodiment of the present invention, which is a block diagram of the liquid crystal display shown in terms of a sensing unit, and FIG. Equivalent circuit diagram for negative.

As illustrated in FIG. 7, the liquid crystal display according to another exemplary embodiment of the present invention includes separate vertical sensing data lines SX _{1 to} SX _M to which the plurality of sensing units SU are connected, as compared with FIG. 3. The reset transistors Qr1 connected to the and vertical sensing data lines SX _{1 to} SX _M are not formed, and the plurality of vertical sensing units SU ′ and the sensing signal output are output to the image data lines D _{1 to} D _m . SOUT is connected. Except this, the liquid crystal display according to another exemplary embodiment of the present invention is the same as the components illustrated in FIGS. 1 to 4, and thus, the same reference numerals are assigned to components having the same structure and functioning the same. Detailed description will be omitted.

In FIG. 7, the sensing signal output unit SOUT is formed on all of the image data lines D ₁ -D _m , but image data in which the sensing signal output unit SOUT is formed according to the resolution of the sensing unit SU ′. The number of lines D ₁ -D _m may vary. That is, the lower the resolution of the sensing unit, the smaller the number of image data lines D ₁ -D _{m on} which the sensing signal output unit SOUT is formed. As described above with reference to FIG. 3, the sensing signal output unit SOUT is formed in the edge region of the liquid crystal panel assembly 300 as described above.

As illustrated in FIG. 8, the vertical sensing unit SU ′ is disposed between the variable capacitor Cv ′ connected to any one image data line DL, the image data line DL, and the reference voltage Vref. It includes a reference capacitor Cp 'which is connected.

The reference capacitor Cp 'may be parasitic capacitors generated in the pixel PX connected to the image data line DL. In addition, the reference capacitor Cp 'is formed on a different layer from the image data line D ₁ -D _m , and a separate reference voltage line to which a constant voltage is applied and the image data line DL may overlap each other with an insulator interposed therebetween. have. In this case, the reference voltage line may be formed using the same material as the image scan line.

The variable capacitor Cv 'uses the image data line DL and the common electrode 270 of the common electrode display panel 200 as two terminals, and the liquid crystal layer 3 between the two terminals functions as a dielectric. The capacitance of the variable capacitor Cv 'is changed by an external stimulus such as a user's touch applied to the liquid crystal panel assembly 300.

 For example, the external stimulus may be a pressure. When pressure is applied to the common electrode display panel 200, the spacer is compressed and deformed so that the distance between the two terminals is changed to change the capacitance of the variable capacitor Cv, and the reference capacitor Cp. The magnitude of the contact voltage Vn 'between') and the variable capacitor Cv 'varies. This contact voltage Vn 'flows through the image data line DL as a sensing data signal. At this time, the reference capacitor Cp 'has a fixed capacitance, and the reference voltage Vref applied to the reference capacitor Cp' has a constant voltage value, so that the contact voltage Vn 'varies in a certain range. Therefore, as described above with reference to FIG. 4, the sensing data signal may always have a voltage range within a predetermined range, thereby easily determining whether or not the contact is made.

Next, referring to FIGS. 9 and 10, the sensing data line signal output from the sensing unit SU ′ connected to the image data line DL is output to the sensing signal processing unit 800 through the sensing signal output unit SOUT. The operation to be described will be described.

FIG. 9 is a circuit diagram of an example of a sensing signal output unit connected to one image data line in a liquid crystal display according to another exemplary embodiment. FIG. 10 is a driving timing diagram of the sensing signal output unit illustrated in FIG. 9. to be.

As illustrated in FIG. 10, during the display period of one frame, the data driver normally outputs the data voltage Vd ′ corresponding to the pixels of each row, thereby charging the pixels connected to each image scanning line G ₁ -G _n . This can be done normally. After the data voltage Vd 'corresponding to all pixels connected from the first image scanning line G ₁ to the last image scanning line G _n is applied, the sensing operation is performed through the sensing signal output unit SOUT when the porch section is reached. Do this.

As described above with reference to FIG. 5, the control signals Vsw2 and Vsw3 have a turn-on voltage Ton for turning on corresponding transistors Qs1 and Qr2 and a turn-off voltage Toff for turning off. The turn-on voltage Ton may use the gate-on voltage Von and the turn-off voltage Toff may use the gate-off voltage Voff.

When the operation of reading the detection signal flowing through each image data line DL starts, the data driver applies a DC voltage of a predetermined level to each image data line DL in the porch section, thereby applying each image data line DL. Reset to the voltage of that level. At this time, a stabilization period is provided before and after the porch section for stabilization of the data driver, and the DC voltage is applied to avoid the stabilization section, but these stabilization sections are not necessarily required. In the stabilization period, the image data lines D ₁ -D _m may be in a high impedance state.

As such, when the initialization operation of the image data line DL is completed, the sensing signal output unit SOUT outputs a sensing data signal output from the corresponding image data line DL according to the state of the control signals Vsw2 and Vsw3 applied. .

Therefore, the control signal Vsw2 outputs the turn-on voltage Ton to the control terminal of the first output transistor Qs to turn on the first output transistor Qs1, and thus the operation may be performed depending on whether the sensing unit SU 'is in contact. through varying the second output transistor (Qs2) operation to the output data line current based on the _{(OY 1 -OY N, OX 1} -OX M) is output as the detected signal data. Even in this case, the turn-on voltage Ton of the control signal Vsw2 may be applied when the common voltage Vcom swinging the high level and the low level every 1H is at the high level.

Therefore, the sensing signal processor 800 reads a sensing signal applied through each image data line DL. As described above, since the sensing signal changes according to the level change of the common voltage Vcom, the reading time of the sensing signal is preferably read before the common voltage Vcom changes to the low level.

Since the sensing data signal is changed based on the DC voltage applied to the image data line DL, the sensing data signal may always have a voltage range within a predetermined range, thereby easily determining whether or not the contact is made.

After the sensing signal processor 800 reads the sensing signal, the reset control signal Vsw3 becomes the turn-on voltage Ton to turn on the reset transistor Qr2. Then, the driving voltage Vss, which may be the ground voltage, is applied to the sensing data line SL to reset the sensing data line SL to the ground voltage. The reset control signal Vsw3 outputs the turn-on voltage Ton until the display section of the next frame is reached, and the second output transistor Qs2 is turned off until the display section of the next frame is reached, thereby unnecessary operation. Reduces power consumption.

The turn-on voltage Ton of the control signal Vsw2 may be applied when the common voltage Vcom is at a low level. At this time, the sensing signal is read before the common voltage Vcom is changed to the high level.

The image data line DL, in which the sensing signal output unit SOUT is not formed, maintains the DC voltage applied in the porch section until the display section of the next frame starts.

As such, since a detection signal for detecting whether a finger or the like is touched is transmitted using the image data line DL, there is no need to form a separate vertical sensing data line. As a result, the aperture ratio of the liquid crystal display is increased, and the distortion of the sensing data signal Vn ′ caused by the change of the image data signal can be reduced due to the narrow gap between the image data line and the vertical sensing data line. In addition, image quality deterioration due to the unbalance of the arrangement of the portion where the vertical sensing data line is formed and the portion that is not is reduced is also reduced. Moreover, since there is no need to form the vertical sensing data line, the structure of the manufacturing process and the liquid crystal panel assembly is simplified and the manufacturing cost is also reduced.

Next, another example of the sensing signal output unit of the liquid crystal display according to the exemplary embodiment of the present invention will be described with reference to FIGS. 11 and 12.

FIG. 11 is a circuit diagram of another example of a sensing signal output unit connected to one image data line in a liquid crystal display according to another exemplary embodiment. FIG. 12 is a driving timing diagram of the sensing signal output unit illustrated in FIG. 11.

As illustrated in FIG. 11, the sense signal output unit SOUT ′ is the same except that the selection transistor Qt is further included in comparison with FIG. 10, and therefore the same reference numerals are assigned to the same components. The detailed description thereof is omitted.

The selection transistor Qt is also a three-terminal element like a thin film transistor, the input terminal of which is connected to the image data line DL and the output terminal of which is connected to the control terminal of the output transistor Qs2 and the output terminal of the reset transistor Qr2. The control terminal is connected to the selection signal Vsel.

In this case, the sensing signal output unit SOUT ′ may be integrated into one integrated circuit (IC) chip, and may be mounted in an edge region or an exposed region of the liquid crystal panel assembly.

As described above with reference to FIG. 10, during the display period of one frame, the data driver normally outputs a data voltage Vd 'corresponding to each pixel of the row, and is connected to each image scanning line G ₁ -G _n . The charging operation of the can be made normally. After the data voltage Vd 'corresponding to all pixels connected from the first image scanning line G ₁ to the last image scanning line G _n is applied, when the porch section is reached, the sensing signal output unit SOUT' detects the data voltage. Perform the action.

The control signals Vsw2 and Vsw3 have a turn-on voltage Ton for turning on the transistors Qr2 and Qs1 and a turn-off voltage Toff for turning off, respectively, and the selection signal Vsel is also a selection transistor Qt. Has a turn-on voltage (Ton) to turn on and a turn-off voltage (Toff) to turn off. The levels of the turn-on voltage Ton and the turn-off voltage Toff applied to each of the signals Vsw2, Vsw3, and Vsel may be the same or different from each other.

Next, when the display period elapses and the data voltage Vd 'corresponding to the pixels connected to all the image scanning lines G ₁ -G _n is applied, and the porch section is applied, the detection signal flowing through each image data line DL is applied. A read operation of the < RTI ID = 0.0 > is started, as shown in FIG. Therefore, a signal flowing through the image data DL is applied to the detection signal output unit SOUT '.

Next, the data driver applies a DC voltage of a predetermined level to each image data line DL as the data voltage Vd 'in the porch section, and initializes each image data line DL to the voltage of the corresponding level. At this time, the stabilization section located before and after the porch section is also not necessary.

As such, when the initialization operation of the image data line DL is completed, the sensing signal output unit SOUT outputs a sensing data signal output from the corresponding image data line DL.

Therefore, after turning on the first output transistor Qs1 by outputting the turn-on voltage Ton to the control signal Vsw2, the operation of the second output transistor Qs2 whose state changes depending on whether or not the sensing unit SU 'is contacted. the data is output as the detection signal via the corresponding current output data line _{(OY 1 -OY N, OX 1} -OX M) based on. Therefore, the sensing signal processor 800 reads a sensing signal applied through each image data line DL.

After the sensing signal processor 800 reads the sensing signal, the reset control signal Vsw3 outputs the turn-on voltage Ton to turn on the reset transistor Qr2 to reach the display section of the next frame. The image data line DL to which (SOUT ') is connected is initialized to the driving voltage Vss.

As a result, as described above with reference to FIGS. 9 and 10, the aperture ratio of the liquid crystal display is increased, and the distortion of the sensing data signal Vn ′ due to the change of the image data signal can be reduced, The deterioration of image quality due to the unbalance of the arrangement depending on the formation is reduced. In addition, the manufacturing process and the structure of the liquid crystal panel assembly are simplified and manufacturing costs are also reduced. In addition, since the signal of the image data line DL is transmitted to the sensing signal output unit SOUT 'only in the read section of the sensing signal, the lifespan of the sensing signal output unit SOUT' is extended and reliability is improved. Since the signal output unit SOUT 'is implemented as one integrated circuit, it is easy to install and design.

In an exemplary embodiment of the present invention, the data driver applies a DC voltage to the image data lines D ₁ -D _m during the entire porch section or the entire porch section except the stabilization section, but the image only at a predetermined time after the porch section starts. After applying a DC voltage to the data lines D ₁ -D _m , the floating state can be maintained.

In the embodiment of the present invention, a variable capacitor and a reference capacitor are taken as examples, but the present invention is not limited thereto, and other types of sensing elements may be used. In addition, in the exemplary embodiment of the present invention, the liquid crystal display device is described as a display device, but the present invention is not limited thereto. In addition, the flat panel display device such as a plasma display device and an organic light emitting display device may be used. The same can be applied.

According to the present invention, since the sensing signal for detecting the touch of the finger or the like is transmitted using the image data line, there is no need to form a separate vertical sensing data line. As a result, the aperture ratio of the display device is increased and the distortion of the sensing data signal due to the change of the image data signal can be reduced due to the narrow gap between the image data line and the vertical sensing data line. In addition, image quality deterioration due to the unbalance of the arrangement of the portion where the vertical sensing data line is formed and the portion that is not is reduced is also reduced. Moreover, since there is no need to form the vertical sensing data line, the structure of the manufacturing process and the liquid crystal panel assembly is simplified and the manufacturing cost is also reduced.

 In addition, since the signal of the image data line is transmitted to the sensing signal output part only in the reading section of the sensing signal, the life of the sensing signal output part is extended and reliability is improved, and the sensing signal output part is implemented as one integrated circuit. Easy to design

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (10)

A plurality of pixels, A plurality of image data lines for transmitting the image data signal to the pixel; A plurality of image scanning lines for transmitting an image scanning signal to the pixels; A plurality of first sensing units, A plurality of second sensing units, A plurality of sensing data lines connected to the plurality of first sensing units and transferring a first sensing data signal; and A plurality of first sensing signal output parts connected to the sensing data lines and generating one output signal based on the first sensing data signal Including, The plurality of second sensing units are connected to at least one of the plurality of image data lines, and the at least one image data line transmits a second sensing data signal. At least one second sensing signal output unit generating one output signal based on the second sensing data signal; Display device. In claim 1, A common electrode facing the image data line and to which a constant voltage is applied; Each of the first sensing units includes a reference capacitor having a constant capacitance and a variable capacitor formed between the at least one image data line and the common electrode. In claim 2, And the reference capacitor is a parasitic capacitor formed in a pixel connected to the at least one image data line. In claim 2, A reference voltage line formed on a layer different from the image data line and receiving a constant voltage; And the reference capacitor is a capacitor formed between the reference voltage line and the at least one data line. In claim 4, And the reference voltage line is formed of the same material as the image scan line. In claim 1, The image data line transmits a voltage of a predetermined level in a porch section. In claim 1, The first detection signal output unit, A first transistor connected to an input terminal with a first driving voltage, a first control signal connected to a control terminal, and an output terminal connected to the sensing signal output unit; A second transistor having an input terminal connected to an output terminal of the first transistor, an output terminal connected to a second driving voltage, and a sensing signal data line connected to a control terminal; and And a third transistor having an input terminal connected to the second driving voltage, a second control signal connected to a control terminal, and an output terminal connected to a sense signal data line. In claim 1, The second detection signal output unit, A first transistor connected to an input terminal with a first driving voltage, a first control signal connected to a control terminal, and an output terminal connected to the sensing signal output unit; A second transistor having an input terminal connected to an output terminal of the first transistor, an output terminal connected to a second driving voltage, and the at least one image data line connected to a control terminal; and A third transistor connected to the second driving voltage, a second control signal connected to a control terminal, and an output terminal connected to the at least one image data line; Display device. In claim 1, The second detection signal output unit, A first transistor connected to an input terminal with a first driving voltage, a first control signal connected to a control terminal, and an output terminal connected to the sensing signal output unit; A second transistor having an input terminal connected to an output terminal of the first transistor and an output terminal connected to a second driving voltage; A third transistor having an input terminal connected to the second driving voltage and a second control signal connected to a control terminal; An input terminal connected to the at least one image data line, a control terminal connected to the third control signal, and an output terminal connected to a control terminal of the second transistor and an output terminal of the third transistor; Containing 4 transistors Display device. In claim 9, The fourth transistor is turned on during the porch period.

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