KR100964598B1 - Liquid Crystal Display Device - Google Patents

Abstract

A liquid crystal display device capable of preventing a decrease in transmittance and improving a reflectance is disclosed. The first substrate includes a color filter and a common electrode. The second substrate includes a pixel portion configured to display an image and a light sensing portion configured to detect an incident light from the outside, the liquid crystal layer comprising a first substrate and a first substrate. It is interposed between 2 boards. The wirings constituting the pixel portion and the light sensing portion on the second substrate are designed to pass through the outermost portion of the transmission area. Therefore, it is possible to minimize the decrease in the transmittance and improve the reflectance by preventing the area reduction and light leakage of the transmission area by the wiring.

Description

[0001] The present invention relates to a liquid crystal display device,

1 is a plan view of a conventional touch panel integrated transflective liquid crystal display device.

2 is a cross-sectional view of a transflective liquid crystal display device according to a first embodiment of the present invention.

3 is an enlarged cross-sectional view of the liquid crystal display panel illustrated in FIG. 2.

4 is a plan view of the array substrate shown in FIG. 2.

FIG. 5 is a plan view illustrating the array substrate of FIG. 4 in detail.

6A through 6D are plan views illustrating a manufacturing process of the array substrate illustrated in FIG. 5.

7 is a plan view illustrating an array substrate of a transflective liquid crystal display according to a second exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: array substrate 200: color filter substrate

210: color filter 300: liquid crystal layer

400: liquid crystal display panel 800: light pen

810: light emitting diodes T1, T2, T3: thin film transistor

GL: Gate Line CSL: Capacitor Storage Line

SGL1, SGL2: Sensor Gate Line DL: Data Line                 

ROL: read line SVL: source voltage line

PP: pixel part LSP: light sensing part

TE: transparent electrode RE: reflective electrode

W1: transmission window W2: opening window

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device that can prevent a decrease in transmittance and improve a reflectance.

In general, the touch panel is provided at the top of the image display apparatus to be in direct contact with the hand and the object so that the instructions displayed on the screen of the image display apparatus can be selected by a human hand or an object.

The touch panel grasps the touched position, and the image display device receives the content indicated at the touched position as an input signal and is driven according to the input signal. Since the touch panel image display device does not require a separate input device that is connected to and operate with an image display device such as a keyboard and a mouse, its use is increasing.

Recently, touch panels have been used in liquid crystal displays, and touch panel liquid crystal displays include a liquid crystal display panel for displaying an image and a touch panel provided on an upper side of the liquid crystal display panel to receive a predetermined input from a user and detect position information. do.

The touch panel liquid crystal display uses a frame in which an air layer is formed between the liquid crystal display panel and the touch panel or uses an adhesive. Thus, layers having different refractive indices are formed between the liquid crystal display panel and the touch panel, thereby degrading the overall optical characteristics of the touch panel liquid crystal display device. In addition, since the first and second transparent electrodes and the first and second substrates provided in the touch panel must be provided, manufacturing costs are increased and the overall thickness of the touch panel liquid crystal display device is also increased.

Accordingly, a display sensor can be improved and the overall thickness can be reduced by incorporating a light sensing unit for outputting an analog signal having position information provided with light in response to light provided from the display surface in a liquid crystal display panel for displaying an image. Touch panel integrated liquid crystal display device has been developed.

1 is a plan view of a conventional touch panel integrated liquid crystal display device.

Referring to FIG. 1, in a touch panel integrated liquid crystal display, a thin film transistor (LST) having a light sensing function should be formed in order to add a touch screen panel function to an array substrate, and a coordinate recognition function should be added. . Therefore, the gate line GL, the data line DL, the source voltage line SVL, the read line ROL, the thin film transistor, and the like must be designed in the existing panel space, thereby having a very low aperture ratio.

In addition, since the wirings pass through the transmission region, the area of the transmission region is reduced, and light leakage occurs due to the wiring, thereby lowering the transmittance.

Accordingly, an object of the present invention is to provide a liquid crystal display device which can prevent a decrease in transmittance and improve a reflectance.

A liquid crystal display device for achieving the above object of the present invention comprises a first substrate including a color filter and a common electrode; A second substrate including a pixel portion configured to display an image on a surface facing the first substrate and displaying an image, and a photo detector configured to sense light incident from the outside; And a liquid crystal layer interposed between the first substrate and the second substrate, wherein the wirings constituting the pixel portion and the light sensing portion on the second substrate pass through the outermost portion of the transmission area. It features.

Preferably, the reflective region is formed on the wires passing through the outermost part of the transmissive region.

The light detector may be disposed under the red pixel of the color filter to detect light incident through the red pixel from the outside, and the light detector may be disposed under the green pixel of the color filter to allow the light to be detected. The light incident through the green pixel may be sensed.

According to such a liquid crystal display device, the wirings are designed to pass through the outermost part of the transmission area in a range where coupling and electrical short do not occur, thereby minimizing the reduction of the area of the transmission area and preventing light leakage of the wiring. Therefore, the decrease in transmittance can be minimized.

In addition, by forming a reflective area on the wires passing through the most surgical part of the transmissive area, the reflectance can be greatly improved.                     

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view of a liquid crystal display device according to the present invention. In particular, a transflective liquid crystal display device is shown.

Referring to FIG. 2, the transflective liquid crystal display of the present invention includes a liquid crystal display panel 400, a light sensing unit LSP, a reader (not shown), and a driver (not shown).

The liquid crystal display panel 400 implements a display surface 410 for displaying an image and receives light provided by a user through the display surface 410.

The LCD panel 400 includes an array substrate 100 having a plurality of pixel parts PP for displaying an image, a color filter substrate 200 facing the array substrate 100, and the array substrate. And a liquid crystal layer 300 interposed between the 100 and the color filter substrate 200.

The light detector LSP is embedded in the liquid crystal display panel 400 to sense light incident through the display surface 410 of the liquid crystal display panel 400, and has an analog signal having position information input thereto. Output to provide to the reader. That is, the light detector LSP is formed in a matrix form on the array substrate 100 of the liquid crystal display panel 400.

The reading unit not only controls the driving of the light sensing unit LSP so that the light sensing unit LSP can sense light in response to a control signal provided from the driving unit, but also inputs the light sensing unit LSP. Converts the analog signal into a digital signal. In addition, the reader transmits the converted digital signal to the driver.

The driving unit provides a control signal for controlling driving of the reading unit to the reading unit, and outputs a driving signal for driving the liquid crystal display panel 400 in response to a digital signal provided from the reading unit. Accordingly, the liquid crystal display panel 400 displays an image in response to the driving signal.

Here, the ratio of the photo detector LSP to the entire area of the array substrate 100 is smaller than that of the pixel portion PP. Therefore, it is possible to reduce the decrease in the overall aperture ratio of the liquid crystal display panel 400 by the light sensing unit LSP.

On the other hand, the color filter substrate 200 is a substrate provided with a color filter 210 consisting of red (R), green (G), blue (B) color pixels.

The red pixel of the color filter 210 is disposed to face the light sensing units LSP. Accordingly, the white light WL incident through the display surface 410 of the liquid crystal display panel 400 is changed into red light RL after passing through the red pixel and is provided to the light sensing units LSP.

In the overall wavelength range of the input light, not only the transmittance of the light passing through the green pixel and the blue pixel is smaller than that of the red light passing through the red pixel, but also the wavelength band in which the transmittance is high is wider than the blue light and the green light. Therefore, when the light detector LSP is disposed corresponding to the red pixel, the sensitivity of the light detector LSP may be improved.                     

The white light WL is provided by the user through the light pen 800 outside the liquid crystal display panel 400. The light pen 800 includes a light emitting diode (LED) 810 for generating the light in a portion in contact with the display surface of the liquid crystal display panel 400.

3 is an enlarged cross-sectional view of the liquid crystal display panel illustrated in FIG. 2. 4 is a plan view of the array substrate illustrated in FIG. 2, and FIG. 5 is a plan view specifically illustrating the array substrate illustrated in FIG. 4.

3 to 5, each pixel portion PP extends in a gate line GL extending in a first direction D1 and in a second direction D2 perpendicular to the first direction D1. Data line DL, the first thin film transistor T1 connected to the gate line GL and the data line DL, and the transparent electrode TE and the reflective electrode RE connected to the first thin film transistor T1. ).

The first thin film transistor T1 may be disposed on the first gate electrode branched from the gate line GL, the first source electrode branched from the data line DL, and the transparent electrode TE and the reflective electrode RE. It is made of a first drain electrode connected.

Each of the photo detectors LSP includes first and second sensor gate lines SGL1 and SGL2 extending in the first direction D1, and a second thin film transistor for photo sensing driven by light provided from the outside. T2), a third thin film transistor T3 electrically connected to the second thin film transistor T2 to output the first signal provided to the second thin film transistor T2, and extending in the second direction D2. And a source voltage line SVL for transmitting the first signal to the second thin film transistor T2, and extending in the second direction D2 and extending from the third thin film transistor T3 to the first signal. It includes a read line (ROL) for receiving the input to transmit to the reader.

The photosensitive second thin film transistor T2 may include a second gate electrode branched from the second sensor gate line SGL2, a second source electrode branched from the source voltage line SVL, and the third thin film transistor ( And a second drain electrode connected to T3). The second sensor gate line SGL2 is formed on the same layer as the gate line GL and is electrically insulated from each other in a state spaced apart from the gate line GL at a predetermined interval. The source voltage line SVL is formed on the same layer as the data line DL and is electrically insulated from the data line DL at a predetermined interval.

The third thin film transistor T3 may include a third gate electrode branched from the first sensor gate line SGL1, a third source electrode connected to the second drain electrode of the second thin film transistor T2, and the read line ( A third drain electrode branched from ROL). The first sensor gate line SGL1 is formed on the same layer as the gate line GL and is electrically insulated from each other in a state spaced apart from the gate line GL at a predetermined interval. The read line ROL is formed on the same layer as the data line DL and is electrically insulated from each other in a state spaced apart from the data line DL at a predetermined interval.

The transparent electrode TE is formed through the contact hole CON exposing the drain electrode of the first thin film transistor T1 on the insulating layer covering the first to third thin film transistors T1, T2, and T3. 1 is electrically connected to the thin film transistor T1. The transparent electrode TE may be formed of a transparent conductive film such as indium tin oxide (ITO) or indium zinc oxide (IZO).

The reflective electrode RE is formed on the transparent electrode TE and has a transmission window W1 exposing a portion of the transparent electrode TE and an opening window W2 exposing the second thin film transistor T2. Has The reflective electrode RE may be made of a single reflective film made of aluminum-neodymium (AlNd) having a high reflectance or a double reflective film made of aluminum-neodymium (AlNd) and molybdenum (MoW).

The transmission window W1 forms a transmission area for transmitting the first light incident from the rear surface of the liquid crystal display panel 400. The reflective electrode RE forms a reflective region that reflects the second light when the second light provided from the outside of the liquid crystal display is incident through the display surface 410 of the liquid crystal display panel 400.

The wirings constituting the pixel part PP and the light sensing part LSP, preferably the data line DL, the source voltage line SVL, and the read line ROL, do not have a coupling and an electrical short. It is designed to pass through the outermost part of the transmission window (W1) in the range. Therefore, since the wires do not pass through the transmission area, the reduction of the transmittance can be prevented by minimizing the area reduction of the transmission area to prevent light leakage due to the wiring. In addition, reflectance may be maximized by forming a reflection area on the wires passing through the most surgical part of the transmission area.                     

The opening window W2 exposes the light sensing second thin film transistor T2 so that the white light WL deliberately provided by the user outside the liquid crystal display panel 400 passes through the red pixel and the red light RL. It is easy to be applied to the second thin film transistor T2 after being changed to).

Here, the reflective electrode RE covers the first and third thin film transistors T1 and T3 to prevent the first and third thin film transistors T1 and T3 from reacting to the red light RL. .

The driving method of the touch panel integrated transflective liquid crystal display device having the above-described array substrate structure is as follows.

First, when the user provides the white light WL through the display surface 410 of the liquid crystal display panel 400 using the light pen, the white light WL passes through the red pixel R to the red light RL. After the change, the light sensing unit LSP is provided in the liquid crystal display panel 400. The second thin film transistor T2 of the photodetector LSP is driven in response to the red light RL.

When the second thin film transistor T2 is driven, the first signal provided to the second source electrode of the second thin film transistor T2 through the source voltage line SVL is a second drain of the second thin film transistor T2. Output to the electrode. Here, the first signal is output from a driver for driving the liquid crystal display panel 400 and includes image information, and is a data driving voltage applied to the liquid crystal capacitor through the first thin film transistor T1.                     

Thereafter, the third thin film transistor T3 is driven by the second signal provided to the first sensor gate line SGL1. Then, the first signal output from the second drain electrode of the second thin film transistor T2 is provided to the third source electrode of the third thin film transistor T3 and then the third of the third thin film transistor T3. Output to the drain electrode. The second signal is a gate driving voltage output from the driver and applied to the first gate electrode of the first thin film transistor T1.

Accordingly, in the transflective liquid crystal display device having the above-described structure, an input signal provided from the outside of the liquid crystal display panel 400 through an optical sensor LSP embedded in the liquid crystal display panel 400 may be used. Light) and drives the liquid crystal display panel 400 in response to the input signal.

Hereinafter, a manufacturing process of the array substrate illustrated in FIG. 5 will be described with reference to FIGS. 6A to 6D.

Referring to FIG. 6A, a first conductive material (not shown) is entirely formed on the array substrate 100, and the first conductive material is patterned by photolithography to form a first conductive pattern.

The first conductive pattern includes a gate line GL extending in a first direction D1, a first sensor gate line SGL1, and a second sensor gate line SGL2.

The first conductive pattern may include a first gate electrode GE1 of the first thin film transistor T1 branched from the gate line GL, and a second thin film transistor branched from the second sensor gate line SGL2. A second gate electrode GE2 of T2 and a third gate electrode GE3 of the third thin film transistor T3 branched from the first sensor gate line SGL1 are further included.

The first conductive pattern may further include a storage line CSL constituting the liquid crystal capacitor.

Referring to FIG. 6B, a gate insulating film (not shown) is formed on the array substrate 100 on which the first conductive pattern is formed, and a semiconductor film (not shown) is formed on the gate insulating film.

Subsequently, the semiconductor layer may be patterned by a photolithography process to form first to third semiconductor patterns (eg, first to third gate electrodes GE1, GE2 and GE3) of the first to third thin film transistors T1, T2, and T3. SP1, SP2, SP3) are formed respectively.

Referring to FIG. 6C, a second conductive material (not shown) is formed on the array substrate 100 on which the first to third semiconductor patterns SP1, SP2, and SP3 are formed, and the second conductive material is photographed. Patterning is performed by an etching process to form a second conductive pattern.

The second conductive pattern includes a data line DL, a source voltage line SVL, and a read line ROL extending in a second direction D2 perpendicular to the first direction D1.

In addition, the second conductive pattern may be branched from the first source electrode, the first drain electrodes SE1 and DE1, and the source voltage line SVL of the first thin film transistor T1 branched from the data line DL. Second source electrode and second drain electrode SE2 and DE2 of second thin film transistor T2 and third source electrode and third drain electrode of third thin film transistor T3 branched from the read line ROL. (SE3, DE3) further.                     

Referring to FIG. 3 again, an insulating film is formed on the entire surface of the array substrate 100 on which the second conductive pattern is formed, and the insulating film is partially etched to form the first drain electrode DE1 of the first thin film transistor T1. The exposed contact hole CON is formed. Preferably, the insulating film is made of a photosensitive organic film and a plurality of embossing is formed on the surface thereof to improve the reflectance.

Subsequently, a transparent conductive film such as ITO or IZO is deposited on the contact hole CON and the insulating layer, and patterned by a photolithography process to form a first drain electrode of the first thin film transistor T1 through the contact hole CON. The transparent electrode TE is electrically connected to DE1).

6D, a metal film having a high reflectance such as aluminum-neodymium (AlNd) is deposited on the transparent electrode TE and the insulating layer and patterned by a photolithography process to expose a portion of the transparent electrode TE. A reflective electrode RE having a transmission window W1 and an opening window W2 exposing the second thin film transistor T2 is formed.

As shown in FIG. 4, the transmission window W1 forms a transmission region, and the reflection electrode RE forms a reflection region. The opening window W2 exposes the second thin film transistor T2 for detecting light, thereby facilitating incident light from the light pen to the second thin film transistor T2.

The reflective electrode RE covers the first and third thin film transistors T1 and T3 to prevent the first and third thin film transistors T1 and T3 from reacting to the light provided from the light pen. Form. In addition, the reflective electrode RE may be uniformly disposed on the pixel portion where the second thin film transistor T2 is disposed and the pixel portion where the second thin film transistor T2 is not disposed to reduce point defects. Form a reflective area.

7 is a plan view illustrating an array substrate of a transflective liquid crystal display according to a second exemplary embodiment of the present invention.

Referring to FIG. 7, in the transflective liquid crystal display according to the second exemplary embodiment of the present invention, the reflective region of the array substrate includes a pixel portion in which the second thin film transistor T2 for detecting light is disposed, that is, a pixel corresponding to a red pixel. The first embodiment is the same as the above-described first embodiment except that the portion and the second thin film transistor T2 are not uniformly formed in the pixel portion corresponding to the green and blue pixels.

As such, if the reflective regions are uniformly formed in all the pixel portions on the array substrate 100, point defects may be reduced and reflectance may be improved.

As described above, according to the transflective liquid crystal display device of the present invention, the wirings are designed to pass through the outermost portion of the transmission area in a range where coupling and electrical short are not generated, thereby minimizing the reduction of the area of the transmission area and the light leakage phenomenon of the wiring. To prevent. Therefore, the decrease in transmittance can be minimized.

In addition, by forming a reflective area on the wires passing through the most surgical part of the transmissive area, the reflectance can be greatly improved.

In addition, by uniformly forming the reflective region in the pixel portion where the light sensing portion of the array substrate is disposed and the pixel portion in which the light sensing portion is not disposed, it is possible to reduce point defects and improve reflectance.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (12)

A first substrate including a color filter and a common electrode; A second substrate including a pixel portion configured to display an image on a surface facing the first substrate and displaying an image, and a photo detector configured to sense light incident from the outside; And A liquid crystal layer interposed between the first substrate and the second substrate, And wires forming the pixel portion and the light sensing portion on the second substrate to pass through the outermost portion of the transmission area. The liquid crystal display device of claim 1, wherein the light detector is disposed under the red pixel of the color filter to sense light incident from the outside through the red pixel. The liquid crystal display of claim 1, wherein the light detector is disposed under the green pixel of the color filter to sense light incident from the outside through the green pixel. The liquid crystal display device according to claim 1, wherein the reflection area is formed on the wirings passing through the outermost part of the transmission area. The method of claim 1, wherein each pixel unit Gate lines; A data line insulated from the gate line; A first thin film transistor connected to the gate line and the data line; And And a pixel electrode connected to the first thin film transistor. The method of claim 1, wherein the light detecting unit First and second sensor gate lines; A second thin film transistor driven by the light to output a first signal; A third thin film transistor for outputting the first signal provided from the second thin film transistor; A source voltage line for transferring the first signal to the second thin film transistor; And And a read line for receiving the first signal from the third thin film transistor and transmitting the first signal to a read unit converting a digital signal. The method of claim 6, wherein the second thin film transistor comprises a gate electrode branched from the second sensor gate line, a source electrode branched from the source voltage line, and a drain electrode connected to the third thin film transistor. Liquid crystal display device. The liquid crystal of claim 6, wherein the third thin film transistor includes a gate electrode branched from the first sensor gate line, a source electrode connected to the second thin film transistor, and a drain electrode branched from the read line. Display. The method of claim 6, wherein the second substrate further comprises a data line, And the data line, the source voltage line, and the read line are designed to pass through the outermost portion of the transmission area. The liquid crystal display device of claim 5, wherein the pixel electrode includes a transparent electrode and a reflective electrode having a transparent window overlapping the transparent electrode and exposing a portion of the transparent electrode. The liquid crystal display of claim 10, wherein the reflective electrode has an opening window that exposes the second thin film transistor such that light incident from the outside into the red pixel of the color filter is provided to the second thin film transistor. Device. The liquid crystal display device of claim 1, wherein the reflective area is uniformly formed in a pixel portion in which the light sensing unit is disposed and in a pixel portion in which the light sensing unit is not disposed.

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