KR20050117464A - Display device and driving method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a driving method thereof, the display device comprising: a display panel, a backlight for irradiating light to the display panel, a first optical sensor for receiving a first light and an external light and a backlight light, and blocking the external light from the external light. And a third optical sensor configured to receive a backlight light and generate a second sensed signal, and a third optical sensor configured to receive external light and backlight light and generate a third sensed signal according to a user's contact. And a signal reading unit for receiving predetermined signal processing, and a signal controller for adjusting the third sensing signal based on the processed first and second sensing signals. According to the present invention, by adjusting the detection signal of the third optical sensor by using the detection signal of the first and second optical sensor, even if the external environment changes, the third optical sensor can accurately determine the contact information according to the user's contact The detection signal of can be obtained.

Description

Display device and driving method thereof {DISPLAY DEVICE AND DRIVING METHOD THEREOF}

The present invention relates to a display device and a driving method thereof.

A typical liquid crystal display (LCD) includes 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 adjust the transmittance of light passing through the liquid crystal layer to obtain a desired image. In this case, in order to prevent degradation caused by an electric field applied to the liquid crystal layer for a long time, the polarity of the data voltage with respect to the common voltage is inverted frame by frame, row by pixel, or pixel by pixel.

Recently, a product having an optical sensor in such a liquid crystal display has been developed. When the user's hand or touch pen touches the screen of the liquid crystal display, the optical sensor detects a change in light and provides the same to the liquid crystal display. The liquid crystal display determines contact information such as whether there is a contact and a contact position and transmits the contact information to the external device, and the external device transmits an image signal based on the contact information to the liquid crystal display device. The optical sensor may be formed by attaching a separate touch panel to the liquid crystal display, but the liquid crystal display may increase in thickness and weight, and may not accurately display letters or pictures.

Therefore, a technology for forming an optical sensor including a thin film transistor inside a pixel displaying an image in a liquid crystal display has been developed. However, since the output characteristics of the optical sensor change according to the external environment, that is, the intensity of the external light, the brightness of the backlight, the temperature, and the like, the optical sensor may cause a large error in the optical sensing according to the user's contact. Accordingly, the liquid crystal display may determine that the user does not touch the screen even when the user touches the screen, and may determine that the user touches the touch screen without touching the screen.

Accordingly, a technical object of the present invention is to provide a display device and a driving method thereof capable of generating a stable output signal of an optical sensor so as to accurately determine contact information according to a user's contact even when the external environment changes.

According to an aspect of the present invention, there is provided a display device including: a display panel, a backlight for irradiating light to the display panel, an external light, and a first optical sensor receiving the backlight light to generate a first sensing signal; A second optical sensor which is blocked from external light and receives the backlight light to generate a second sensing signal, and a signal reading unit which receives the first and second sensing signals from the first and second optical sensors and processes a predetermined signal; And a signal controller configured to determine a sensing state according to the intensity of the external light based on the processed first and second sensing signals from the signal reading unit, and to perform a predetermined control operation according to the sensing state.

The signal controller generates at least one state determination signal based on the processed first and second detection signals, determines the detection state based on the at least one state determination signal, and determines the at least one state. The signal may include a first determination signal that is a difference between the processed first sensing signal and the processed second sensing signal.

The signal controller may adjust the magnitude of the first detection signal by adjusting the gain of the signal reader.

The signal controller may adjust the brightness of the backlight according to the sensing state.

The first optical sensor may include a sensing element, and the signal controller may adjust the sensitivity of the first optical sensor by adjusting a control voltage of the sensing element.

The signal reader may amplify the first and second sensed signals and convert the amplified first and second sensed signals into digital signals.

The at least one state determination signal is a difference between a second determination signal that is a difference between an input maximum allowed signal of the signal reader and the processed first sensing signal and a difference between an input allowed minimum signal of the signal reader and the processed second detection signal. 3 may further include a determination signal.

The sensing state includes a first state and a second state, and the signal controller may be configured such that the first determination signal is greater than a first setting value and the second determination signal is greater than the first predetermined value in the initial state of the detection state. If less than a second set value, the detection state is changed from the first state to the second state, and if the first determination signal is less than or equal to the first predetermined value or the second determination signal is greater than or equal to the second predetermined value. Maintaining the first state, and in the second state, when the first determination signal is less than a third set value and the third determination signal is less than a fourth set value, the sensing state is set in the second state. The second state may be maintained when the first determination signal is greater than or equal to the third predetermined value or when the third determination signal is greater than or equal to the fourth predetermined value.

The sensing state may include first to third states, and the signal controller may be configured such that the first determination signal is greater than or equal to a first predetermined value and the second determination signal is in the first state, which is an initial state of the sensing state. When the detection state is greater than or equal to a second set value, the detection state is changed from the first state to the second state, and when the first determination signal is greater than or equal to the first setting value and the second determination signal is smaller than the second setting value. The detection state is changed from the first state to the third state, and when the first determination signal is smaller than the first set value, the first state is maintained, and in the second state, the first determination signal Is less than a third set value, the detection state is changed from the second state to the first state, and the first determination signal is greater than or equal to the third set value and the second determination signal is greater than or equal to a fourth set value. Remind the detection state The detection state is changed from the second state to the first state when the first determination signal is greater than or equal to the third set value and the second determination signal is smaller than the fourth set value. Change to a third state, and in the third state, when the first determination signal is smaller than a fifth set value, change the sensing state from the third state to the first state, and the first determination signal is set to the third state. If the value is equal to or greater than 5, the third state can be maintained.

The first and second photosensors may include sensing elements made of amorphous silicon or polycrystalline silicon thin film transistors.

The first optical sensor may be located in a display area of the display panel, and the second optical sensor may be located outside the display area.

The electronic device may further include a temperature sensor which is blocked from the external light and the backlight light and generates a third sensing signal, and further performs the predetermined control operation based on the third sensing signal.

According to another exemplary embodiment of the present disclosure, a method of driving a display device including a backlight for irradiating light may include receiving external light and the backlight light to generate a first sensing signal, blocking the external light, and blocking the backlight light. Receiving and generating a second detection signal, generating at least one state determination signal based on the first and second detection signals, and depending on the intensity of the external light based on the at least one state determination signal And determining a detection state, wherein the at least one state determination signal is a difference signal between the first detection signal and the second detection signal.

The method may further include adjusting the magnitude of the first sensing signal according to the sensing state.

The method may further include adjusting the brightness of the backlight according to the sensing state.

According to another exemplary embodiment of the present invention, a display device includes a display panel, a backlight for irradiating light to the display panel, an external light, and a first optical sensor that receives the backlight light and generates a first detection signal, and is blocked from the external light. A second optical sensor that receives the backlight light and generates a second sensing signal; a third optical sensor that receives the external light and the backlight light and generates a third sensing signal according to a user's contact; and the first to third lights A signal reading unit which receives the first to third sensing signals from a sensor, respectively, and performs a predetermined signal processing; and the first of the third optical sensors based on the processed first and second sensing signals from the signal reading unit. And a signal controller for adjusting the sensed signal.

The signal controller may adjust the third sensing signal such that a difference between the processed first and second sensing signals falls between a first set value and a second set value.

The signal controller may adjust the third detection signal by adjusting a control voltage input to the third optical sensor.

The signal controller may adjust the third detection signal by adjusting the gain of the signal reader.

The signal controller may adjust the third detection signal by adjusting the brightness of the backlight.

The signal controller may adjust a control voltage input to the third optical sensor such that the processed first sensing signal is between a third set value and a fourth set value.

When the processed first sensing signal is less than or equal to the third set value, a voltage variation value may be added to the control voltage, and when the processed first sensing signal is greater than or equal to the fourth set value, the voltage variation value may be subtracted from the control voltage. .

If the difference is less than or equal to the first set value, a gain variation value may be added to the gain of the signal reading unit, and if the difference is greater than or equal to the second set value, the gain variation value may be subtracted from the gain.

When the gain is an upper limit of gain and the difference is less than or equal to the first set value, the backlight brightness may be increased by a predetermined variation unit.

If the backlight brightness is an upper limit of variation, the gain may be changed to a gain center value and the backlight brightness may be changed to a lower limit of variation.

The first and second optical sensors may include a plurality of first and second sensing elements, respectively, and the processed first and second sensing signals may be average values of output signals of the first and second sensing elements, respectively. have.

The first and third optical sensors may be located in a display area of the display panel, and the second optical sensor may be located outside the display area.

The light blocking member may further include a light blocking member that blocks the second optical sensor from the external light.

The light blocking member may be a black matrix that prevents light leakage of the display panel.

The light blocking member may be a reflector reflecting the external light.

The signal reading unit and the signal control unit may be mounted on a single chip.

According to another aspect of the present invention, there is provided a method of driving a display device including a backlight for irradiating light, the method comprising: receiving external light and the backlight light to generate a first sensing signal, blocking the external light and blocking the backlight light; Receiving and generating a second detection signal, receiving the external light and the backlight light, generating a third detection signal according to a user's contact, and generating the third detection signal based on the first and second detection signals. Adjusting the.

The adjusting may include adjusting the third sensing signal such that a difference between the first and second sensing signals falls between a first set value and a second set value.

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 and a driving method thereof according to an embodiment of the present invention will now be described in detail with reference to the drawings.

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

As shown in FIG. 1, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel assembly 300, an image scanning unit 400, a data driver 500, and a sensing scan connected thereto. The unit 700, the signal reader 800, the backlight 900 for irradiating light to the liquid crystal panel assembly 300, the driving voltage generator 950 for supplying the necessary voltages thereof, and a signal controller for controlling them 600).

The liquid crystal panel assembly 300 is connected to a plurality of signal lines G ₁ -G _n , D ₁ -D _m , S ₁ -S _N , P ₁ -P _M , P _SG , and P _SD in an equivalent circuit. It includes a plurality of pixels arranged in a substantially matrix form.

The signal lines G ₁ -G _n and D ₁ -D _m include a plurality of image scanning lines G ₁ -G _n for transmitting an image scanning signal and data lines D ₁ -D _m for transmitting an image data signal. do. The image scanning lines G ₁ -G _n extend substantially in the row direction and are substantially parallel to each other, and the data lines D ₁ -D _m extend substantially in the column direction and are substantially parallel to each other.

The signal lines S ₁ -S _N and P ₁ -P _M include a plurality of sensing scan lines S ₁ -S _N for transmitting a sensing scan signal and sensing signal lines P ₁ -P _M for transmitting a sensing signal. . The sensing scan lines S ₁ -S _N extend approximately in the row direction and are substantially parallel to each other, and the sensing signal lines P ₁ -P _M extend substantially in the column direction and are substantially parallel to each other.

The signal lines P _SG and P _SD include a control voltage line P _SG for transmitting the control voltage V _SG and an input voltage line P _SD for transferring the input voltage V _SD , and extend in the row or column direction. have.

Each pixel includes a switching element Q _S1 connected to a signal line G ₁ -G _n , D ₁ -D _m , and a liquid crystal capacitor C _LC and a storage capacitor C _ST connected thereto. It includes. The holding capacitor C _ST can be omitted as necessary.

The switching element Q _S1 , such as a thin film transistor, is a three-terminal element whose control terminal and input terminal are connected to the image scanning line G ₁ -G _n and the data line D ₁ -D _m, respectively, and the output terminal is a liquid crystal. It is connected to a capacitor (C _LC ) and a holding capacitor (C _ST ).

The pixel also includes an optical sensor, which includes a sensing element Q _P connected to the signal lines P _SG and P _SD , and a switching element Q _S2 connected to the signal lines S ₁ -S _N and P ₁ -P _M. And a sense signal capacitor C _P connected thereto. However, not all pixels need to include such optical sensors, for example, one pixel of the plurality of pixels may include an optical sensor, or may include an optical sensor for each pixel placed at intervals of 1 to 2 mm. That is, the formation density of the photosensor may be adjusted as needed, and accordingly, the number of the sensing scan lines S ₁ -S _N and the sensing signal lines P ₁ -P _M may be adjusted.

The sensing element Q _P is a three-terminal element whose control terminal and input terminal are connected to the control voltage line P _SG and the input voltage line P _SD, respectively, and the output terminal is a sensing signal capacitor C _P and a switching element. Is connected to (Q _S2 ). In the sensing element Q _P , when the channel semiconductor is irradiated with light, the channel semiconductor consisting of amorphous silicon or polycrystalline silicon forms a photo current, and the photo current is generated by the input voltage V _SD applied to the input voltage line P _SD . Flows in the direction of the sense signal capacitor C _P and the switching element Q _S2 .

The sensing signal capacitor C _{P is} connected between the sensing element Q _P and the control voltage line P _SG , and accumulates charges according to the photocurrent from the sensing element Q _P to maintain a predetermined voltage. The sensing signal capacitor C _P may be omitted as necessary.

The switching element Q _S2 is also a three-terminal element whose control terminal, output terminal and input terminal are connected to the sensing scan lines S ₁ -S _N , the sensing signal lines P ₁ -P _M and the sensing elements Q _P, respectively. It is. The switching element Q _S2 is a voltage stored in the sensing signal capacitor C _P or the sensing element Q _P when a voltage for turning on the switching element Q _S2 is applied to the sensing scan lines S ₁ -S _N. The photocurrent from is output to the sensing signal lines P ₁ -P _M as the sensing signals V _P1 -V _PM .

The switching elements Q _S1 and Q _S2 and the sensing element Q _P may be formed of amorphous silicon or poly crystalline silicon thin film transistors.

The driving voltage generator 950 may input various voltages necessary for the liquid crystal display, that is, a gate on voltage V _on and a gate off voltage V _off for turning on / off the switching elements Q _S1 and Q _S2 . The voltage V _SD and the control voltage V _SG are generated.

The image scanning unit 400 is connected to the image scanning lines G ₁ -G _n of the liquid crystal panel assembly 300 so that the gate on voltage V _on and the gate off voltage V _off from the driving voltage generator 950 are provided. An image scanning signal consisting of a combination of the two is applied to the image scanning lines G ₁ -G _n .

The data driver 500 is connected to the data lines D ₁ -D _m of the liquid crystal panel assembly 300 to apply a data voltage corresponding to the image data signal to the pixel.

The sensing scan unit 700 is connected to the sensing scan lines S ₁ -S _N of the liquid crystal panel assembly 300 so that the gate-on voltage V _on and the gate-off voltage V _off from the driving voltage generator 950 can be obtained. A sensing scan signal consisting of a combination of is applied to the sensing scan lines S ₁ -S _N.

Signal reading unit 800 is input a sense signal (V _P1 -P _PM) output is connected to the detection signal of the liquid crystal panel assembly _{(300) (P 1 -P M} ) via the detected signal line (P ₁ -P _M) Receive and perform predetermined signal processing.

The backlight 900 is positioned at the rear of the liquid crystal panel assembly 300 to irradiate light to the liquid crystal panel assembly 300, and typically includes a plurality of lamps.

The signal controller 600 controls operations of the image scanner 400, the data driver 500, the sensing scanner 700, the signal reader 800, the backlight 900, and the driving voltage generator 950. do.

The image scanning unit 400, the data driving unit 500, the sensing scanning unit 700, or the signal reading unit 800 may be mounted directly on the liquid crystal panel assembly 300 in the form of a plurality of driving integrated circuit chips, or may be flexible printed. It may be mounted on a flexible printed circuit film (not shown) and attached to the liquid crystal panel assembly 300 in the form of a tape carrier package (TCP). Alternatively, the image scanning unit 400, the data driver 500, the sensing scanning unit 700, or the signal reading unit 800 may be integrated in the liquid crystal panel assembly 300.

Alternatively, the image scanning unit 400, the data driver 500, the sensing scanning unit 700, the signal reading unit 800, and the signal control unit 600 may be a single chip (not shown), also called a one-chip. Can be done. By integrating the processing units 400, 500, 600, 700, and 800 driving the liquid crystal display in a single chip, the mounting area may be reduced and power consumption may be reduced. Of course, if necessary, the circuit elements used in each processing unit or each processing unit may be placed outside a single chip.

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

The signal controller 600 may control the input image signals R, G, and B and their display from an external graphic controller (not shown), for example, a vertical sync signal V _sync and a horizontal sync signal. (H _sync ), a main clock (MCLK), a data enable signal (DE) is provided. The signal controller 600 properly processes the image signals R, G, and B according to operating conditions of the liquid crystal panel assembly 300 based on the input image signals R, G, and B and the input control signal, and controls image scanning. After generating the signal CONT1 and the data control signal CONT2, the image scan control signal CONT1 is sent to the image scanning unit 400, and the data control signal CONT2 and the processed image signal DAT are the data driver. Export to 500. In addition, the signal controller 600 generates a sensing scan control signal CONT3 based on the input control signal and sends it to the sensing scan unit 700.

Image scan control signal (CONT1) includes at least one clock signal and the like to control the output of the start scan indicating the scanning start of a gate-on voltage (V _on) signal (STV) and the gate-on voltage (V _on).

The data control signal CONT2 is a horizontal synchronization start signal STH for transmitting data of one pixel row, a load signal LOAD for applying a corresponding data voltage to the data lines D ₁ -D _m , and a common voltage V _com. ), The inversion signal RVS, the data clock signal HCLK, and the like, which inverts the polarity of the data voltage (hereinafter, referred to as "polarity of the data voltage" by reducing the "polarity of the data voltage" with respect to the common voltage)).

After the data driver 500 receives the image data (DAT) for the pixels of one line according to the data control signal (CONT2) from the signal controller 600 is converted to the corresponding data voltage it the data lines (D ₁ - D _m ).

The image scanning unit 400 applies the gate-on voltage V _on 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- . The switching element Q _S1 connected to G _n is turned on, and accordingly, a data voltage applied to the data lines D ₁ -D _m is applied to the corresponding pixel through the turned on switching element Q _S1 .

The difference between the data voltage applied to the pixel and the common voltage V _com is shown as the charging voltage of the liquid crystal capacitor C _LC , that is, the pixel voltage. The transmittance of light passing through the pixel changes according to the magnitude of the pixel voltage, thereby displaying a desired image.

After one horizontal period (or "1H") (one period of the horizontal sync signal H _sync and the data enable signal DE) has passed, the data driver 500 and the image scanning unit 400 may perform the pixel processing on the next row of pixels. Repeat the same operation. In this manner, the gate-on voltage V _on is sequentially applied to all the image scanning lines G ₁ -G _n during one frame to apply the data voltage to all the pixels. At the end of one frame, the next frame starts and the state of the inversion signal RVS applied to the data driver 500 is controlled so that the polarity of the data voltage applied to each pixel is opposite to that of the previous frame ("frame inversion). "). In this case, the polarities of the data voltages flowing through one data line are changed according to the characteristics of the inversion signal RVS even in one frame (eg, inverted rows and inverted dots) or the polarities of the data voltages applied to one pixel row are also different from each other. (Eg: nirvana, point inversion).

The sensing scan unit 700 sequentially applies the gate-on voltage V _on to the sensing scan lines S ₁ -S _N according to the sensing control signal CONT3 from the signal control unit 600, and the signal reading unit 800. Reads the sensing signals V _P1 -V _PM applied to the sensing signal lines P ₁ -P _M. The signal reader 800 amplifies and filters the read sensing signals V _P1 -V _PM and converts them into digital signals for transmission to the signal controller 600. The signal controller 600 performs appropriate arithmetic processing on the digital signal to find out whether or not it is touched and the position of the touch, and transmits the information to the external device, and the external device transmits an image signal based on the information to the liquid crystal display device. .

Next, the structure of the liquid crystal display according to the exemplary embodiment of the present invention will be described in detail with reference to FIGS. 3 to 5.

3 is an example of a layout view of a liquid crystal display according to an exemplary embodiment of the present invention, and FIGS. 4 and 5 are cross-sectional views of the liquid crystal display of FIG. 3 taken along lines IV-IV 'and VV', respectively. to be.

The liquid crystal display according to the exemplary embodiment of the present invention includes a thin film transistor array panel 100 and a common electrode panel 200 facing each other, and a liquid crystal layer interposed between the thin film transistor array panel 100 and the common electrode panel 200. It consists of (3).

First, as illustrated in FIGS. 3 to 5, the thin film transistor array panel 100 includes a plurality of image scanning lines 121, a plurality of storage electrode lines 131, and a plurality of sensing on the insulating substrate 110. A scanning scanning line 127 and a plurality of control voltage lines 129 are formed.

The scan lines 121 and 127 and the control voltage line 129 mainly extend in the horizontal direction and are separated from each other, and transmit the image scan signal, the sense scan signal, and the control voltage V _SG , respectively, and each of the plurality of control terminal electrodes ( control electrodes 124, 128, 126. The control voltage line 129 includes a control voltage line 129 and an extension 123 extending from the control terminal electrode 126.

The storage electrode line 131 mainly extends in the horizontal direction and includes a plurality of protrusions constituting the storage electrode 133. The storage electrode line 131 receives a predetermined voltage such as a common voltage applied to the common electrode 270 of the common electrode display panel 200.

The scan lines 121 and 127, the sustain electrode line 131, and the control voltage line 129 are made of aluminum-based metals such as aluminum and aluminum alloys, silver-based metals such as silver and silver alloys, copper-based metals such as copper and copper alloys, and molybdenum And a molybdenum-based metal such as molybdenum alloy, chromium, titanium, and tantalum are preferable. The scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129 may include two layers having different physical properties, that is, a lower layer (not shown) and an upper layer (not shown) thereon. have. The upper layer is made of a low resistivity metal such as aluminum (Al) or aluminum alloy to reduce signal delay or voltage drop of the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129. It is made of a series of metals. In contrast, the lower layer is made of a material having excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum (Mo), molybdenum alloy, chromium (Cr), and the like. An example of the combination of the lower layer and the upper layer is chromium / aluminum-neodymium (Nd) alloy.

The scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129 may have a single layer structure or may include three or more layers.

In addition, the scanning lines 121 and 127, the sustain electrode line 131, and the control voltage line 129 are inclined with respect to the surface of the substrate 110, and the inclination angle thereof is about 30-80 ° with respect to the surface of the substrate 110. .

An insulating layer 140 made of silicon nitride (SiNx) is formed on the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129.

A plurality of linear semiconductors 151 and a plurality of island-like semiconductors 156, 158, and 159 made of hydrogenated amorphous silicon (amorphous silicon is abbreviated a-Si) and the like are formed on the insulating layer 140. have. The linear semiconductor 151 extends mainly in the longitudinal direction, from which a plurality of projections 154 extend toward the control terminal electrode 124, from which the plurality of extensions 157 extend. In addition, the linear semiconductor 151 increases in width near the point where the scan lines 121 and 127, the sustain electrode line 131, and the control voltage line 129 meet, and thus the scan lines 121 and 127, the sustain electrode line 131, and the control voltage line 129. Covers a large area).

A plurality of linear and island ohmic contacts 161, 162, 164, and 165 made of a material such as n + hydrogenated amorphous silicon doped with high concentration of silicide or n-type impurities on top of the semiconductor 151. 166 and 168 are formed. The linear contact member 161 has a plurality of protrusions 163, and the protrusions 163 and the island contact members 165 are paired and positioned on the protrusions 154 of the semiconductor 151. In addition, the island contact members 162 and 164 and the island contact members 166 and 168 are also paired and positioned on the island semiconductors 156 and 158, respectively.

Side surfaces of the semiconductors 151, 156, 158, and 159 and the ohmic contacts 161, 162, 164, 165, 166, and 168 are also inclined with respect to the surface of the substrate 110, and the inclination angle is 30-80 °.

On the ohmic contact 161, 162, 164, 165, 166, 168 and the insulating layer 140, a plurality of data lines 171, a plurality of input voltage lines 179a, a plurality of sensing signal lines 179b, A plurality of output terminal electrodes 174 and 175 and a plurality of input electrode 176 are formed.

The data line 171, the input voltage line 179a, and the sensing signal line 179b mainly extend in the vertical direction and intersect the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129, respectively. Pass the sense input voltage and sense signal.

Each output terminal electrode 175 includes an extension 177 overlapping one storage electrode 133. Each vertical portion of the data line 171 includes a plurality of protrusions, and the vertical portion including the protrusions forms an input terminal electrode 173 partially surrounding one end of the output terminal electrode 175. One control terminal electrode 124, one input terminal electrode 173, and one output terminal electrode 175, together with the protrusion 154 of the semiconductor 151, form one thin film transistor (TFT). The channel of the thin film transistor is formed in the protrusion 154 between the input terminal electrode 173 and the output terminal electrode 175. This thin film transistor functions as a switching element Q _S1 .

Each input voltage line 179a includes a plurality of horizontal portions and a plurality of vertical portions, and a part of the horizontal portions of the input voltage line 179a includes a plurality of protrusions, and the horizontal portion including the protrusions includes the output terminal electrode 174. An input terminal electrode 172 is formed to partially surround one end of the. One control terminal electrode 126, one input terminal electrode 172, and one output terminal electrode 174 together with the semiconductor 156 constitute one thin film transistor (TFT), and the channel of the thin film transistor is an input terminal. Is formed in the semiconductor 156 between the electrode 172 and the output terminal electrode 174. This thin film transistor functions as a sensing element Q _P.

The output terminal electrode 174 and the input terminal electrode 176 are connected to each other. A branch extending from the sensing signal line 179b toward the input terminal electrode 176 forms the output terminal electrode 178. The pair of input terminal electrodes 176 and output terminal electrodes 178 are each separated from each other and positioned opposite to each other with respect to the control terminal electrode 128. One control terminal electrode 128, one input terminal electrode 176 and one output terminal electrode 178 together with the semiconductor 158 constitute one thin film transistor (TFT), and the channel of the thin film transistor is an input terminal. Is formed in the semiconductor 158 between the electrode 176 and the output terminal electrode 178. This thin film transistor functions as a switching element Q _S2 .

Each output terminal electrode 174 includes an extension 174a that overlaps the extension 123 of one control voltage line 129, and the sense signal capacitor C _P is the two extension 123, 174a. Is created by nesting.

The data line 171, the input voltage line 179a, the sensing signal line 179b, the output terminal electrodes 174 and 175, and the input terminal electrode 176 are made of a refractory metal such as chromium or molybdenum-based metal, tantalum and titanium. Preferably, the film may have a multilayer structure including a lower film (not shown) such as molybdenum (Mo), molybdenum alloy, chromium (Cr) and an upper film (not shown) which is an aluminum-based metal disposed thereon.

The data line 171, the input voltage line 179a, the sensing signal line 179b, the output terminal electrodes 174 and 175, and the input terminal electrode 176 also scan lines 121 and 127, sustain electrode line 131, and control voltage line ( Like 129, the sides are inclined at an angle of about 30-80 degrees, respectively.

The ohmic contacts 161, 162, 164, 165, 166, and 168 may have semiconductors 151, 156, 158, and 159 thereunder, data lines 171, input voltage lines 179a, and sensing signal lines 179b thereon. ), Which exists only between the output terminal electrodes 174 and 175 and the input terminal electrode 176, serves to lower the contact resistance. The linear semiconductor 151 has an exposed portion between the input terminal electrode 173 and the output terminal electrode 175, and is not covered by the data line 171 and the output terminal electrode 175, and in most places, the linear semiconductor 151 is provided. Although the width of the 151 is smaller than the width of the data line 171, the width becomes larger at the portion where the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129 meet, so that the scan lines 121 and 127 and the storage electrode line ( 131 and the insulation between the control voltage line 129 and the data line 171 is strengthened.

Silicon nitride or oxide, which is an inorganic material, is disposed on the data line 171, the input voltage line 179a, the sensing signal line 179b, the output terminal electrodes 174 and 175, and the portion of the input terminal electrode 176 and the exposed semiconductor 151. A passivation layer 180 made of silicon is formed, and an organic insulating layer 187 made of an organic material having excellent planarization characteristics and photosensitivity is formed on the passivation layer 180. In this case, the surface of the organic insulating layer 187 has a concave-convex pattern, and the concave-convex pattern is induced to the reflective electrode 194 formed on the organic insulating layer 187 to maximize the reflection efficiency of the reflecting electrode 194.

In the passivation layer 180 and the organic insulating layer 187, contact holes 185 exposing the extension 177 of the output terminal electrode 175 are formed. The contact hole 185 may be made in various shapes such as polygon or circle shape. The sidewalls of the contact holes 185 are inclined or stepped at an angle of 30-85 °.

A plurality of pixel electrodes 190 are formed on the organic insulating layer 187.

The pixel electrode 190 includes a transparent electrode 192 and a reflective electrode 194 formed on the transparent electrode 192. The transparent electrode 192 is made of ITO or IZO, which is a transparent conductive material, and the reflective electrode 194 may be made of aluminum or an aluminum alloy, silver or silver alloy, which are opaque and have reflectivity. The pixel electrode 190 may further include a contact auxiliary layer (not shown) made of molybdenum or molybdenum alloy, chromium, titanium, or tantalum. The contact auxiliary layer secures contact characteristics between the transparent electrode 192 and the reflective electrode 194 and prevents the transparent electrode 192 from oxidizing the reflective electrode 194.

One pixel is largely divided into a transmission area TA and a reflection area RA. The transmission area TA 195 is an area where the reflection electrode 194 is removed, and the reflection area RA is a reflection electrode ( 194) exists. The organic insulating layer 187 is removed from the transmission area TA 195 so that a cell gap of the transmission area TA 195 and a cell gap of the reflection area RA are different from each other.

An opening 199 is formed on the semiconductor 156 to expose the semiconductor 156 to external light by removing the organic insulating layer 187 and the pixel electrode 190.

The pixel electrode 190 is physically and electrically connected to the extension 177 of the output terminal electrode 175 through the contact hole 185 to receive a data voltage from the output terminal electrode 175. The pixel electrode 190 to which the data voltage is applied rearranges the liquid crystal molecules of the liquid crystal layer 3 between the two by generating an electric field together with the common electrode 270.

In addition, as described above, the pixel electrode 190 and the common electrode 270 form a liquid crystal capacitor C _LC to maintain an applied voltage even after the thin film transistor is turned off. _LC holding capacitor (C _ST ) in parallel. In the storage capacitor C _ST , the extension 177 of the output terminal electrode 175 and the storage electrode 133 are made to overlap each other. The storage capacitor C _ST may be formed by overlapping the pixel electrode 190 and the adjacent image scanning line 121, and the storage electrode line 131 may be omitted.

The pixel electrode 190 overlaps the scan lines 121 and 127 and the neighboring data line 171 to increase the aperture ratio, but may not overlap.

A transparent conductive polymer or the like may be used as the material of the pixel electrode 190, and in the case of a reflective liquid crystal display, an opaque reflective metal may be used.

The light blocking member 220, which is referred to as a black matrix, is formed on the common electrode display panel 200 facing the thin film transistor array panel 100 on a substrate 210 made of an insulating material such as transparent glass. The light blocking member 220 prevents light leakage between the pixel electrodes 190 and defines an opening area facing the pixel electrode 190.

The plurality of color filters 230 are formed on the substrate 210 and the light blocking member 220, and are disposed to substantially enter the opening region defined by the light blocking member 220. The color filters 230 disposed between two neighboring data lines 171 and arranged in the vertical direction may be connected to each other to form a band. Each color filter 230 may represent one of three primary colors such as red, green, and blue.

An overcoat 250 made of an organic material is formed on the color filter 230 and the light blocking member 220 to protect the color filter 230 and to flatten the surface.

The common electrode 270 made of a transparent conductive material such as ITO or IZO is formed on the overcoat 250.

A polarizer (not shown) for polarizing light is attached to an outer surface of at least one of the two display panels 100 and 200 of the liquid crystal panel assembly 300.

Meanwhile, the liquid crystal display according to an exemplary embodiment of the present invention uses at least one reference light sensor (PSA, PSB) for sensing external light and / or backlight light in order to adjust the detection signal of the display light sensor inside the pixel. The reference photosensors PSA and PSB will be described in detail with reference to FIGS. 6A to 8.

6A and 6B are schematic views illustrating a reference light sensor of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 7 is a position in which the reference light sensor shown in FIGS. 6A and 6B is mounted on the liquid crystal panel assembly. 8 is a schematic block diagram illustrating a signal reader and a signal controller of a liquid crystal display according to an exemplary embodiment of the present invention.

The reference photo sensor PSA illustrated in FIG. 6A is a display photo sensor connected to the sensing scan line S ₁ , and includes a sensing element Q _P , a switching element Q _S2 , and a sensing signal capacitor C _P. do. Therefore, the reference photosensor PSA is located at the top of the display area DA displaying an image in the liquid crystal panel assembly 300 as shown in FIG. 7. However, if necessary, the reference light sensor PSA may be located outside the display area DA, and may be formed separately from the display light sensor. When the reference light sensor PSA is positioned at the top of the liquid crystal panel assembly 300, the reference light sensor PSA may be affected by the shadow of the user as much as possible.

The reference optical sensor PSB shown in FIG. 6B also includes a sensing element Q _P , a switching element Q _S2 , and a sensing signal capacitor C _P like the display unit optical sensor. As shown in FIG. 7, the reference light sensor PSB is located outside the display area DA on the reference light sensor PSA, unlike the reference light sensor PSA, and the sensing scan lines S ₁ -S _N. It is connected to another sensing scan line S ₀ .

Meanwhile, if necessary, the reference light sensors PSA and PSB may be positioned at the bottom of the liquid crystal panel assembly 300. In this case, the reference light sensors PSA are connected to the sensing scan line S _N , and the reference light sensors ( The PSB is positioned outside the display area DA under the reference light sensor PSA.

The reference light sensor PSA receives the external light through the light blocking member 220 and the reflective electrode 194 on the sensing element Q _P , and receives an external light through the opening of the lower or periphery of the reference light sensor PSA. Receives backlight light. In addition, the reference light sensor PSA may receive backlight light guided by a layer constituting the layer or a layer existing together and inside and outside the reference light sensor PSA. The reference light sensor PSA generates a sensing signal depending on the external light and the backlight light when they are irradiated.

In contrast, the reference light sensor PSB blocks the sensing element Q _P from external light by closing the upper portion of the sensing element Q _P by the light blocking member 220 and / or the reflective electrode 194. The backlight may receive backlight light through an opening below or around the optical sensor PSB or guided backlight light as described above. Also, unlike the reference light sensor PSA, the reference light sensor PSB further receives backlight light reflected by the reflective electrode 194. The reference light sensor PSB generates a detection signal depending on the backlight light when it is irradiated.

The liquid crystal display according to the exemplary embodiment of the present invention may include a plurality of such reference light sensors PSA and PSB, and the reference light sensors PSA and PSB, like the light sensor of the display unit, sense signal lines P _1- . P _M) sends out a detection signal (P ₁ -P _M) a sense signal (V _P1 -V _PM) according to the detected scan signal is linked to.

Next, a liquid crystal display according to an exemplary embodiment of the present invention for processing the detection signal by the reference light sensors PSA and PSB will be described with reference to FIGS. 8 and 9.

8 is a block diagram illustrating a signal reader and a signal controller of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 9 is a diagram illustrating a detection signal of a reference light sensor illustrated in FIGS. 6A and 6B. to be.

As shown in FIG. 8, the liquid crystal display includes a signal reader 800, a signal controller 600, a backlight 900, and a driving voltage generator 950.

The signal reader 800 receives a detection signal V _P1 -V _PM from the reference light sensors PSA and PSB through the detection signal lines P ₁ -P _M , and amplifies and / or filters them. 810 and an analog-to-digital converter 820 for converting the adjusted sense signal V _P1 '-V _PM ' from the sense signal adjuster 810 to digital.

The signal controller 600 includes a signal inputter 610, a calculator 620, and a control signal outputter 630, which are sequentially connected. The signal input unit 610, the calculator 620, and the control signal output unit 630 may be formed of digital logic.

The signal input unit 610 receives the sensed signals DV _P1 -DV _PM digitally converted from the analog-digital converter 820 and performs appropriate signal processing. That is, the signal input unit 610 obtains an average from the detection signals DV _P1 -DV _PM of the reference light sensor PSA to generate the detection signal V _SA , and generates the detection signal DV _P1 -of the reference light sensor PSB. DV _PM ) is averaged to generate a sense signal V _SB . In addition, the signal input unit 610 may perform digital filtering. As described above, using the detection signals V _SA and V _SB averaging the output signals of the plurality of reference light sensors PSA and PSB, the detection signals of the single reference light sensors PSA and PSB are compared with those of the single reference light sensors PSA and PSB. Nonuniformity can be prevented.

The calculation unit 620 generates the state determination signals V1, V2, and V3 based on the detection signals V _SA and V _SB from the signal input unit 610. As shown in FIG. 9, the state determination signal V1 is a value obtained by subtracting the detection signal V _SA from the maximum signal Vmax, and the state determination signal V2 is a detection signal V _SA and a detection signal V _SB . The difference value and the state determination signal V3 are defined as the value obtained by subtracting the minimum signal Vmin from the detection signal V _SB . Here, the maximum signal Vmax and the minimum signal Vmin are determined by the sensing signal adjusting unit 810 and the analog-to-digital converter 820, for example, the maximum and minimum values for which they allow input.

The state determination signal V1 is a signal that depends on the intensity of the external light and the luminance of the backlight. The state determination signal V1 is mainly smaller as the intensity of the external light increases. The state determination signal V2 is a signal that depends on the intensity of the external light and the luminance of the backlight. The state determination signal V2 is mainly larger as the intensity of the external light increases. The state determination signal V3 is a signal that depends on the brightness of the backlight. The higher the brightness of the backlight is, the larger the value is.

The calculator 620 determines the sensing state SM depending on the intensity of external light of the liquid crystal display based on the state determination signals V1, V2, and V3. That is, the operation unit 620 compares the state determination signals V1, V2, and V3 with predetermined set values to determine whether the current liquid crystal display is outdoors, indoors, in a bright room, or in a dark room. Etc. can be judged. The sensing state SM may be set to two or more states as necessary. An example of such state determination will be described with reference to FIGS. 10 and 11.

10 is an example of a flowchart of determining a sensing state of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 11 is another example of a flowchart of determining a sensing state of a liquid crystal display according to an exemplary embodiment of the present invention. to be.

In the flowchart shown in FIG. 10, the calculation unit 620 determines the detection state SM by setting the detection state SM to "0" and "1".

First, the calculating unit 620 initializes the sensing state SM to "1" (S10). Then, the state determination signal V1 and the set value Vth1 are compared, and the state determination signal V2 and the set value Vth2 are compared (S20). As a result of the comparison, when the state determination signal V1 is smaller than the set value Vth1 and the state determination signal V2 is larger than the set value Vth2, the detection state SM is changed to "0" (S30), otherwise, detection is performed. Keep the state SM at " 1 ".

When the detected state SM is "0", the state determination signal V2 is compared with the set value Vth3 and the state determination signal V3 is compared with the set value Vth4 (S40). As a result of the comparison, when the state determination signal V2 is smaller than the set value Vth3 and the state determination signal V3 is smaller than the set value Vth4, the detection state SM is changed to "1" (S10), otherwise The sensing state SM is kept at "0".

In this case, when the sensing state SM is "1", the intensity of the external light is small or the difference between the intensity of the external light and the backlight is small, which may correspond to the interior. When the sensing state SM is "0", the intensity of the external light is large. When the difference between the intensity of the external light and the backlight light is large, it may correspond to the outdoors.

The calculating unit 620 transmits the result of determining the sensing state SM to the control signal output unit 630. The control signal output unit 630 controls the backlight 900, the driving voltage generator 950, and the sensing signal adjuster 810 according to the sensing state SM.

That is, the control signal output unit 630 transmits the backlight control signal BLC to the backlight 900 to adjust the brightness of the backlight. For example, when the detection state SM is "0", the backlight 900 may be turned off, and when the detection state SM is "1", the backlight on / off control may be performed to turn on the backlight 900.

In addition, the control signal output unit 630 transmits the gain control signal AG to the sensing signal adjusting unit 810 to adjust the gain of the sensing signal adjusting unit 810. Accordingly, the sensing signals V _P1 -V _PM from the reference light sensors PSA and PSB and the display part light sensors are adjusted in size and transmitted to the analog-digital converter 820.

The control signal output unit 630 transmits the voltage control signal SG to the driving voltage generator 950 to change the level of the control voltage V _SG . When the control voltage V _SG is changed, the levels of the detection signals V _P1 -V _{PM of} the reference photosensors PSA and PSB and the display photosensor change.

By controlling the backlight 900, the driving voltage generator 950, and the sensing signal adjusting unit 810 according to the sensing state SM, the sensing signal V _P1 -V _PM of the appropriate size is received from the optical sensor of the display unit. The contact information according to the contact can be determined accurately.

Meanwhile, in the flowchart shown in FIG. 11, the calculation unit 620 determines three detection states SM by "0", "1", and "2".

First, the calculating unit 620 initializes the sensing state SM to "2" (S50). Then, the state determination signal V2 is compared with the set value Vthi1 (S55), and if the state determination signal V2 is smaller than the set value Vthi1, the sensing state SM is kept at " 2 " The determination signal V2 is compared with the set value Vthi2 (S60). As a result of the comparison in step S60, if the state determination signal V2 is smaller than the set value Vthi2, the sensing state SM is kept at " 2 ", otherwise the state determination signal V1 and the set value Vthi3 Is compared (S65). As a result of the comparison in step S65, if the state determination signal V1 is smaller than the set value Vthi3, the detection state SM is changed to "0" (S70), otherwise the detection state SM is changed to "1". Change to (S80).

When the detection state SM is "0", the state determination signal V2 is compared with the set value Vths1 (S75), and when the state determination signal V2 is smaller than the set value Vths1, the detection state SM Is changed to "2" otherwise the detection status (SM) is kept at "0".

When the detection state SM is "1", the state determination signal V2 is compared with the set value Vthw1 (S85), and when the state determination signal V2 is smaller than the set value Vthw1, the detection state SM Is changed to "2", otherwise, the state determination signal V1 is compared with the set value Vthw2 (S90). As a result of the comparison in step S90, if the state determination signal V1 is smaller than the set value Vthw2, the detection state SM is changed to "0", otherwise the detection state SM is changed to "2".

In this example, when the sensing state SM is "0", it may correspond to the outdoor, "1" may correspond to a bright room, and "2" may correspond to a dark room or dark room.

As in the previous example, the control signal output unit 630 controls the backlight 900, the driving voltage generator 950, and the sensing signal adjusting unit 810 according to the sensing state SM. For example, when there is much external light, the control voltage V _SG is lowered or the gain value of the sensing signal adjusting unit 810 is lowered. In particular, in this case, unlike the previous example, dimming control for adjusting the brightness of the backlight 900 may be performed, and the control voltage V _SG and the detection signal adjusting unit 810 of the driving voltage generator 950 may be performed. Gain can be adjusted more precisely.

The calculator 620 may set four or more detection states SM and may determine the detection state SM according to the state determination signals V1, V2, and V3.

The liquid crystal display according to the exemplary embodiment of the present invention may further include a sensor (not shown) having the same structure as that of the display unit optical sensor and blocked from both external light and backlight light. The sensor outputs a detection signal that is not dependent on light but solely on temperature. The sensor further includes the detection signal to determine a detection state (SM), so that the display optical sensor can perform a more stable light detection considering temperature effects. To be.

Then, FIGS. 12 and 13 illustrate a liquid crystal display according to another exemplary embodiment of the present invention, in which a detection signal of an optimal display unit optical sensor corresponding to a change in external light may be obtained using the reference optical sensors PSA and PSB. It demonstrates in detail with FIG.

FIG. 12 is a waveform diagram illustrating a detection signal of a display unit optical sensor according to a sensing mode in a liquid crystal display according to another exemplary embodiment. FIG. 13 is a display unit optical sensor in a liquid crystal display according to another exemplary embodiment. Is an example of a flow chart for adjusting the detection signal.

In the liquid crystal display according to the present exemplary embodiment, the signal reader 800, the signal controller 600, the backlight 900, and the driving voltage generator 950 are similar to those of the previous exemplary embodiment illustrated in FIG. 8. Include.

The signal reading unit 800 includes a sensing signal adjusting unit 810 and an analog-to-digital converter 820, and the signal controller 600 controls the signal input unit 610, the calculation unit 620, and the control signal output unit 630. Include. Since the operation of the signal reading unit 800 and the signal input unit 610 is substantially the same as in the previous embodiment, a detailed description thereof will be omitted.

First, the detection signal waveform of the display optical sensor according to the user's contact will be described with reference to FIG. 12.

12, the horizontal axis represents X coordinates of the sensing signal lines P ₁ -P _M of the liquid crystal panel assembly 300, and the vertical axis represents voltage levels of the sensing signals V _P1 -V _PM at each X coordinate. The detection signal (V _P1 -V _PM) is detected and the output signal of the scanning line (S _i) display a light sensor connected to the sensing scan line (S _i) and the sense signal (P _T) contact the user at which a cross- Assume that there is. In addition, for convenience of description, the detection signal V _PT of the display unit optical sensor at the contacted position X (P _T ) is referred to as a touch voltage and the detection of the display unit optical sensor at the non-contacted position Let signals V _B1 and V _B2 be background voltages.

Waveform 1 of FIG. 12 is a sense signal waveform in a sensing mode called a shadow mode where the contact voltage V _PT is lower than the background voltage V _B1 , and waveform 2 of FIG. It is a sense signal waveform in a sensing mode called a backlight mode, in which the contact voltage V _PT is higher than the background voltage V _B2 . The shadow mode appears when the intensity of the external light is relatively large (bright). In this case, since the external light is larger than the backlight light reflected by the user's touch, the contact voltage is smaller than the background voltage. The backlight mode appears when the intensity of the external light is small (dark). In this case, since the backlight light reflected by the user's touch is larger than the external light, the contact voltage is larger than the background voltage. The background voltage is mainly determined by the intensity of the external light, and the contact voltage is determined by the brightness of the backlight.

The signal controller 600 receives a sensing signal corresponding to the waveform 1 or the waveform 2 of FIG. 12, compares the magnitude of the sensing signal, and determines whether or not the contact is made. That is, the signal controller 600 determines that a contact is made when there is a voltage level out of a predetermined range from the background voltage level, and extracts a contact position.

However, when the liquid crystal display is at the boundary between the shadow mode and the backlight mode, that is, when the difference between the background voltage and the contact voltage (ΔV _S1 , ΔV _S2 ) is small, the two voltages are not distinguished. it's difficult. Therefore, it is necessary to keep the difference between the background voltage and the contact voltage at a constant magnitude.

Then, the operation unit 620 and the control signal output unit 630 of the liquid crystal display according to another embodiment of the present invention for adjusting the detection signal of the display unit optical sensor to maintain the difference will be described in detail with reference to FIG. 13. Explain.

On the other hand, the display optical sensor at the contact position (X (P _T )) is substantially the same state as the reference optical sensor (PSB) is blocked from the external light because it is blocked from the external light according to the user's contact and receives only the backlight light. Will be placed in. Therefore, the sensing signals of the contact voltage V _PT and the reference light sensor PSB have substantially the same voltage level. In addition, since the display optical sensor in the non-contact position receives external light and backlight light, the display optical sensor is substantially in the same state as the reference optical sensor PSA. Therefore, the background voltage and the detection signal of the reference light sensor PSA have substantially the same voltage level. As a result, the difference between the background voltage and the contact voltage is substantially the same as the difference ΔV _S between the detection signals of the reference light sensor PSA and the reference light sensor PSB, and in this embodiment, the reference light sensors PSA and PSB are By controlling the magnitude of the control voltage of the light sensor of the display unit, the gain of the detection signal adjusting unit 810, the brightness of the backlight is adjusted to control the difference (ΔV _S ) to be within a predetermined range.

In the present embodiment, for convenience of description, the backlight control signal BLC, the backlight control variable for calculating the same, the gain control signal AG and the gain control variable, and the voltage control signal SG and the voltage control variable have the same reference signs. The control signal output unit 630 transmits the calculated values of the control variables BLC, AG, and SG to the backlight 900, the detection signal adjusting unit 810, and the driving voltage generator 950 as control signals, respectively. I shall do it.

First, when the operation is started (S100), the calculator 620 and the control signal output unit 630 initialize the backlight 900 and the detection signal adjuster 810 (S105). The control signal output unit 630 substitutes the backlight lower limit value BLC _L to the backlight control variable BLC and transmits it to the backlight 900, and substitutes the gain intermediate value AG _MID to the gain control variable AG to detect the detection signal. The controller 810 transmits the result. The backlight 900 then drives at a standard constant current, for example 15 mA, in accordance with the backlight lower limit BLC _L.

In operation S110, the calculator 620 compares the sensing signal V _SA with the set values V _BL and V _BH .

As a result of the comparison in step S110, when the sensing signal V _SA is less than or equal to the set value V _BL and greater than or equal to the set value V _BH , the sensing signal V _SA is again compared with the set value V _BL (S120). ).

As a result of the comparison in step S120, when the sensing signal V _SA is less than or equal to the set value V _BL , the voltage variation ΔSG is added to the voltage control variable SG (S125), and the sensing signal V _SA is set to the set value. If greater than V _BL , the detection signal V _SA is compared with the set value V _BH (S130).

As a result of the comparison in step S130, if the sensing signal V _SA is equal to or greater than the set value V _BH , the voltage variation ΔSG is subtracted from the voltage control variable SG (S135), and the sensing signal V _SA is set. If it is smaller than the value V _BL , step S110 is performed again.

In steps S110 to S135, the control signal V _SG of the display light sensor and the reference light sensors PSA and PSB is adjusted to adjust the detection signal V _SA of the reference light sensor PSA to the set value V. FIG. _{Make sure to fall} between _BL ) and the set value (V _BH ). In this case, since the background voltage and the contact voltage are within a predetermined range, the detection signal of the display unit optical sensor is input to the signal controller 600 without being distorted.

On the other hand, instead of the control voltage V _SG of the display light sensor and the reference light sensors PSA and PSB, the input voltage V _SD is adjusted so that the detection signal V _SA of the reference light sensor PSA is set to V _BL . You can also enter between and the setpoint (V _BH ).

As a result of the comparison in step S110, if the detection signal V _SA is between the set value V _BL and the set value V _BH , the difference ΔV _S of the detected signal is set to the set value ΔV _SL , ΔV _SH . Compare (S140).

As a result of the comparison in step S140, if the difference ΔV _S is between the set value ΔV _SL and the set value ΔV _SH , step S110 is performed again, and the difference ΔV _S is the set value ΔV _SL. ) Or less than or equal to the set value (ΔV _SH ), the gain control variable AG is compared with the upper limit of the gain AG _MAX , and the difference ΔV _S is compared with the set value ΔV _SL (S150).

As a result of the comparison in step S150, if the gain control variable AG is different from the upper limit of gain AG _MAX or the difference ΔV _S is greater than the set value ΔV _SL , the difference ΔV _S and the set value ΔV _SL . To compare (S160).

As a result of the comparison in step S160, if the difference ΔV _S is less than or equal to the set value ΔV _SL , the gain change value ΔAG is added to the gain control variable AG (S165), and the difference ΔV _S is the set value (ΔV _S ). _If greater than _SL ), the difference ΔV _S is compared with the set value ΔV _SH (S170).

As a result of the comparison in step S170, if the difference ΔV _S is greater than or equal to the set value ΔV _SH , the gain variation ΔAG is subtracted from the gain control variable AG (S175), and the difference ΔV _S is set to the set value ( If smaller than ΔV _SH , step S110 is performed again.

In steps S140 to S175, the difference of the detection signal difference ΔV _S of the reference light sensors PSA and PSB is adjusted by adjusting the gain of the detection signal adjusting unit 810 so that the setting value ΔV _SL and the setting value ΔV _{SH are obtained.} In between). That is, when the difference ΔV _S is small, the gain of the sensing signal adjusting unit 810 is increased, and when the difference ΔV _S is large, the gain of the sensing signal adjusting unit 810 is reduced. As such, when the difference ΔV _S is in a certain range, the background voltage and the contact voltage are clearly distinguished, and thus it is easy to determine whether the user is in contact.

Again, if the gain control variable AG is the upper limit gain AG _MAX and the difference ΔV _S is equal to or less than the set value ΔV _{SL as a} result of the comparison in step S150, the backlight variation ΔBLC is applied to the backlight control variable BLC. Add (S180), and compare the backlight control variable (BLC) and the backlight upper limit (BLC _H ) (S185).

As a result of the comparison in step S185, if the backlight control variable BLC is less than or equal to the backlight upper limit value BLC _H , step S110 is performed again. If the backlight control variable BLC is greater than the backlight upper limit value BLC _H , the gain control variable is performed. The lower limit gain AG _MIN is substituted for AG (S190), the lower backlight value BLC _L is substituted for the backlight control variable BLC (S195), and then step S110 is performed again.

If the difference ΔV _S is not larger than the set value ΔV _SL even when the gain of the detection signal adjusting unit 810 is adjusted to the maximum in steps S150 and S165, the steps S150 and S180 are performed. The brightness of the backlight 900 is adjusted to increase the difference ΔV _S. That is, even when the external light is dark and no matter how much the gain of the detection signal adjusting unit 810 is adjusted, if the background voltage and the contact voltage are not distinguished, the brightness of the backlight 900 is increased to detect the detection signal V _SB of the reference light sensor PSB and Increase the contact voltage of the light sensor. Then, the sensing mode of the liquid crystal display is switched from the shadow mode to the backlight mode, and the background voltage and the contact voltage are distinguished.

If the difference ΔV _S is not greater than the set value ΔV _SL even when the backlight control variable BLC becomes larger than the upper backlight BLC _H in steps S180 and S185, the intensity of external light is increased again. In operation S190 and S195, the gain of the sensing signal adjusting unit 810 is minimized and the luminance of the backlight 900 is set to the lower limit. Then, the sensing mode of the liquid crystal display is switched from the backlight mode to the shadow mode, and the background voltage and the contact voltage are distinguished.

As described above, the control voltage V _SG and the detection signal adjusting unit 810 of the display unit optical sensor are detected by using the detection signals V _SA and V _{SB of the} reference optical sensors PSA and PSB and the difference ΔV _S. By adjusting the gain and the brightness of the backlight 900, the background voltage and the contact voltage of the display optical sensor can be distinguished. Accordingly, it is possible to easily determine whether the contact and the contact position by receiving the detection signal of the display optical sensor.

In the exemplary embodiment of the present invention, the signal input unit 610, the operation unit 620, and the control signal output unit 630 may be implemented by digital logic. The signal input unit 610, the operation unit 620, and the control signal output unit 630 may be programmed using a microprocessor or implemented as an ASIC. chip, or a chip that makes up a signal reader.

Although the liquid crystal display device having the backlight has been described above, the present invention is not limited thereto, and the same may be applied to the light receiving display device including the backlight.

According to the present invention, the liquid crystal display includes a reference optical sensor that depends on the external light and the backlight light and a reference optical sensor that depends only on the backlight light to determine the intensity of the external light from the detection signal of the reference optical sensor. It can accurately sense light and adjust the brightness of the backlight.

In addition, the detection signal of the display unit optical sensor may be obtained by adjusting the detection signal of the display unit optical sensor using the detection signals of the reference optical sensor to obtain the detection signal of the display unit optical sensor that can accurately determine the contact information according to the user's contact even if the external environment changes.

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.

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

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 an example of layout view of a liquid crystal display according to an exemplary embodiment of the present invention.

4 and 5 are cross-sectional views of the liquid crystal display of FIG. 3 taken along lines IV-IV 'and V-V', respectively.

6A and 6B are schematic views illustrating a reference optical sensor of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a position where the reference light sensor illustrated in FIGS. 6A and 6B is mounted on the liquid crystal panel assembly.

8 is a block diagram illustrating a signal reader and a signal controller of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 9 is a diagram illustrating a detection signal of the reference light sensor illustrated in FIGS. 6A and 6B.

10 is an example of a flowchart of determining a sensing state of a liquid crystal display according to an exemplary embodiment of the present invention.

11 is another example of a flowchart of determining a sensing state of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 12 is a waveform diagram illustrating a sensing signal of an optical sensor of a display unit according to a sensing mode in a liquid crystal display according to another exemplary embodiment of the present disclosure.

FIG. 13 is an example of a flowchart of adjusting a detection signal of an optical sensor of a display unit in a liquid crystal display according to another exemplary embodiment of the present invention.

Claims (33)

Display, A backlight for irradiating light onto the display panel, A first optical sensor configured to receive external light and the backlight light and generate a first detection signal; A second optical sensor which is blocked from the external light and receives the backlight light to generate a second detection signal; A signal reading unit which receives the first and second sensing signals from the first and second optical sensors and performs predetermined signal processing; and A signal controller which determines a sensing state according to the intensity of the external light based on the processed first and second sensing signals from the signal reading unit, and performs a predetermined control operation according to the sensing state Display device comprising a. In claim 1, The signal controller generates at least one state determination signal based on the processed first and second detection signals, determines the detection state based on the at least one state determination signal, The at least one state determination signal includes a first determination signal that is a difference between the processed first sensing signal and the processed second sensing signal. Display device. In claim 2, And the signal controller adjusts the gain of the signal reader to adjust the magnitude of the first sensing signal. In claim 2, And the signal controller adjusts the brightness of the backlight according to the sensing state. In claim 2, The first optical sensor includes a sensing element, The signal controller adjusts the control voltage of the sensing element to adjust the sensitivity of the first optical sensor. Display device. In claim 2, The signal reading unit amplifies the first and second sensing signals and converts the amplified first and second sensing signals into digital signals. In claim 2, The at least one state determination signal is a difference between a second determination signal that is a difference between an input maximum allowed signal of the signal reader and the processed first sensing signal and a difference between an input allowed minimum signal of the signal reader and the processed second detection signal. A display device further comprising three determination signals. In claim 7, The sensing state comprises a first and a second state, The signal controller may determine the detected state when the first determination signal is greater than a first predetermined value and the second determination signal is less than a second predetermined value in the first state, which is an initial state of the sensing state. Change from the state to the second state, and maintain the first state if the first determination signal is less than or equal to the first set value or the second determination signal is greater than or equal to the second set value; In the second state, when the first determination signal is smaller than the third setting value and the third determination signal is smaller than the fourth setting value, the sensing state is changed from the second state to the first state, If the first determination signal is greater than or equal to the third predetermined value or the third determination signal is greater than or equal to the fourth predetermined value, the second state is maintained. Display device. In claim 7, The sensing state includes first to third states, The signal controller may determine the detected state when the first determination signal is greater than or equal to a first predetermined value and the second determination signal is greater than or equal to a second predetermined value in the first state, which is an initial state of the sensing state. Change the sensing state from the first state to the third state if the first determination signal is greater than or equal to the first set value and the second determination signal is smaller than the second set value. Change the first determination signal when the first determination signal is smaller than the first set value; In the second state, when the first determination signal is less than a third set value, the detection state is changed from the second state to the first state, and the first determination signal is greater than or equal to the third set value and the If the second determination signal is greater than or equal to a fourth predetermined value, the detection state is changed from the second state to the first state, and the first determination signal is greater than or equal to the third predetermined value and the second determination signal is greater than the fourth determination value. If less than the set value, the detection state is changed from the second state to the third state, In the third state, the detection state is changed from the third state to the first state when the first determination signal is smaller than the fifth setting value, and when the first determination signal is greater than or equal to the fifth setting value, To maintain the third state Display device. In claim 1, The first and second optical sensors include a sensing element made of amorphous silicon or a polycrystalline silicon thin film transistor. In claim 1, And the first optical sensor is located in a display area of the display panel, and the second optical sensor is located outside the display area. In claim 1, A temperature sensor shielding from the external light and the backlight light and generating a third sensing signal, Performing the predetermined control operation based on the third detection signal; Display device. A driving method of a display device including a backlight for irradiating light, Generating a first sensing signal by receiving external light and the backlight light; Blocking the external light and receiving the backlight light to generate a second detection signal; Generating at least one state determination signal based on the first and second sensing signals, and Determining a sensing state depending on the intensity of the external light based on the at least one state determination signal; Including; The at least one state determination signal is a difference signal between the first detection signal and the second detection signal. Method of driving the display device. In claim 13, And adjusting the magnitude of the first sensing signal according to the sensing state. In claim 13, And adjusting the brightness of the backlight according to the sensing state. Display, A backlight for irradiating light onto the display panel, A first optical sensor configured to receive external light and the backlight light and generate a first detection signal; A second optical sensor which is blocked from the external light and receives the backlight light to generate a second detection signal; A third optical sensor receiving the external light and the backlight light and generating a third detection signal according to a user's contact; A signal reading unit which receives the first to third sensing signals from the first to third optical sensors, and performs predetermined signal processing; and A signal controller which adjusts the third sensed signal of the third photosensor based on the processed first and second sensed signals from the signal readout Display device comprising a. The method of claim 16, And the signal controller adjusts the third sensing signal such that a difference between the processed first and second sensing signals falls between a first set value and a second set value. The method of claim 17, The signal controller adjusts the third sensing signal by adjusting a control voltage input to the third optical sensor. The method of claim 17, And the signal controller adjusts the gain of the signal reader to adjust the third sensing signal. The method of claim 17, The signal controller adjusts the third sensing signal by adjusting the brightness of the backlight. The method of claim 17, And the signal controller adjusts a control voltage input to the third optical sensor such that the processed first sensing signal is between a third set value and a fourth set value. The method of claim 21, A display that adds a voltage variation to the control voltage if the processed first sensed signal is less than or equal to the third set value, and decreases the voltage variation at the control voltage if the processed first sensed signal is greater than or equal to the fourth set value Device. The method of claim 17, And a gain variation value is added to a gain of the signal reading unit when the difference is equal to or less than the first set value, and the gain variation value is subtracted from the gain when the difference is greater than or equal to the second set value. The method of claim 23, And increasing the backlight brightness by a predetermined variation unit when the gain is an upper limit of gain and the difference is less than or equal to the first set value. The method of claim 24, And changing the gain to a gain center value if the backlight brightness is an upper limit of variation and changing the backlight brightness to a lower limit of variation. The method of claim 16, The first and second optical sensors each include a plurality of first and second sensing elements, and wherein the processed first and second sensing signals are average values of output signals of the first and second sensing elements, respectively. Device. The method of claim 16, The first and third optical sensors are located in a display area of the display panel, and the second optical sensor is located outside the display area. The method of claim 16, And a light blocking member which blocks the second optical sensor from the external light. The method of claim 28, The light blocking member is a black matrix that prevents light leakage of the display panel. The method of claim 28, And the light blocking member is a reflector reflecting the external light. The method of claim 16, And the signal reading unit and the signal control unit are mounted on a single chip. A driving method of a display device including a backlight for irradiating light, Generating a first sensing signal by receiving external light and the backlight light; Blocking the external light and receiving the backlight light to generate a second detection signal; Receiving the external light and the backlight light and generating a third sensing signal according to a user's contact; and Adjusting the third sensing signal based on the first and second sensing signals Method of driving a display device comprising a. 33. The method of claim 32, And adjusting the third sensing signal such that a difference between the first and second sensing signals falls between a first set value and a second set value.