KR20070087331A - Liquid crystal display device - Google Patents

Abstract

A liquid crystal display device is provided to form dummy pixels of a non-display area in a stair shape structure at portions corresponding to corners of sealant, thereby preventing overlapping between the sealant and pixels and improving reliability of the liquid crystal display device. A liquid crystal display device includes a first display panel such as a thin film transistor array panel(100) formed with a plurality of pixels and dummy pixels, a second display panel such as a common electrode display panel(200) facing the first display panel, and a sealant(311) joining the first and second display panels together, wherein the sealant is in the curved line shape at corners. The dummy pixels are surrounded by the sealant and in the stair shape structure at portions adjacent to the corners of the sealant.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

1 is a block diagram of a display device 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 a perspective view of a conventional liquid crystal display device.

4 is a perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

※ Explanation of symbols on main parts of drawing ※

100: thin film transistor display panel 200: common electrode display panel

3: liquid crystal layer 230: color filter

191: pixel electrode 270: common electrode

The present invention relates to a liquid crystal display device.

Recently, with the rapid development of the information society, the need for a flat panel display having excellent characteristics such as thinning, light weight, and low power consumption has emerged.

Among such flat display devices, a liquid crystal display (LCD) is one of the flat panel display devices most widely used at present. The liquid crystal display includes two display panels on which an electric field generating electrode is formed and a liquid crystal layer interposed therebetween, and determines a direction of liquid crystal molecules of the liquid crystal layer by generating an electric field in the liquid crystal layer by applying a voltage to the electric field generating electrode. And transmittance of light passing through the liquid crystal layer.

Among the liquid crystal display devices, which are currently mainly used are structures in which electric field generating electrodes are provided on two display panels, respectively. Among these, a plurality of pixel electrodes are arranged in a matrix form on one display panel (hereinafter referred to as a thin film transistor display panel), and one common electrode covers the entire display panel on another display panel (hereinafter, referred to as a common electrode display panel). The structure is mainstream.

Image display in such a liquid crystal display device is performed by applying a separate voltage to each pixel electrode. To this end, a gate line for connecting a thin film transistor (TFT), which is a three-terminal element for switching a voltage applied to the pixel electrode, to each pixel electrode and transmitting a signal for controlling the thin film transistor; A data line is formed to transfer a voltage to be applied to the pixel electrode. The thin film transistor serves as a switching element that transfers or blocks the data signal transmitted through the data line to the pixel electrode according to the scan signal transmitted through the gate line.

Meanwhile, a gap is formed between the thin film transistor array panel and the common electrode panel to secure a gap for injecting liquid crystal, to fix the thin film transistor array panel and the common electrode panel, and to seal the liquid crystal.

The encapsulant is applied to surround the thin film transistor array of the thin film transistor array panel using a seal print method using a screen mask and a drop method using a seal dispenser.

Meanwhile, the sealing material using the dropping method is formed on the thin film transistor array panel according to the moving direction of the support plate supporting the thin film transistor array panel.

Accordingly, the sealing material line is formed in a curved shape as the moving direction of the support plate is switched at the corners of the thin film transistor array panel, that is, the corners thereof, and thus, the vertices and the curves of the rectangular thin film transistor array array are formed. As the margin between the sealing line of the type is reduced and overlapped with each other, the reliability of the liquid crystal display may be lowered.

Therefore, the technical problem of this invention is improving the reliability of a liquid crystal display device.

The liquid crystal display according to the present invention bonds a first display panel having a plurality of pixels and dummy pixels, a second display panel facing the first display panel, and the first and second display panels, and the corner portion is curved. The dummy pixel includes a phosphorus sealant, is surrounded by the sealant, and is adjacent to a corner portion of the sealant.

The first display panel may be divided into a display area, a non-display area, and a peripheral area. The display area may include the plurality of pixels, and the non-display area may include the dummy pixel.

An interval between the dummy pixel and the sealing material may be 100 μm or more.

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. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of 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, area, plate, etc. is over another part, this includes not only the part directly above the other part but also another part in the middle. On the contrary, when a part is just above another part, it means that there is no other part in the middle.

A liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

Next, a display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

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

As illustrated in FIG. 1, a display device according to an exemplary embodiment of the present invention includes a display panel unit 300, a gate driver 400 and a data driver 500 connected thereto. ), A gray voltage generator 800 connected to the data driver 500, and a signal controller 600 for controlling the gray voltage generator 800.

Referring to FIG. 1, the display panel unit 300 is connected to a plurality of display panel lines G1 -Gn and D1 -Dm and arranged in a substantially matrix form when viewed in an equivalent circuit. and a plurality of pixels PX constituting a display area DA1.

Referring to FIG. 2, the display panel 300 of the liquid crystal display includes lower and upper display panels 100 and 200 and a liquid crystal layer 3 therebetween. In the case of an organic light emitting diode display, the display panel 300 may include only one display panel.

The display signal lines G1 -Gn and D1 -Dm are a plurality of gate lines G1 -Gn for transmitting a gate signal (also called a "scan signal") and a data line for transmitting a data signal. (D1-Dm). The gate lines G1 -Gn extend substantially in the row direction and are substantially parallel to each other, and the data lines D1 -Dm extend substantially in the column direction and are substantially parallel to each other.

Each pixel PX includes at least one active element (not shown) such as a transistor and at least one capacitor (not shown).

Referring to FIG. 2, each pixel PX of the liquid crystal display device is, for example, a pixel defined by an i-th gate line Gi and a j-th data line Dj, and is connected to display signal lines Gi and Dj. The device Q includes a liquid crystal capacitor CLC and a storage capacitor CST connected thereto. The display signal lines Gi and Dj are disposed on the lower display panel 100, and the storage capacitor CST may be omitted as necessary.

The switching element Q, such as a polysilicon thin film transistor, is provided in the lower panel 100, and a control terminal connected to the gate line Gi, an input terminal connected to the data line Dj, and a liquid crystal capacitor, respectively. It is a three-terminal device with an output terminal connected to the CLC and the holding capacitor CST.

The liquid crystal capacitor CLC has two terminals, the pixel electrode 191 of the lower panel 100 and the common electrode 270 of the upper panel 200, and the liquid crystal layer 3 between the two electrodes 191 and 270 is a dielectric material. Function as. The pixel electrode 191 is connected to the switching element Q, and the common electrode 270 is formed on the front surface of the upper panel 200 and receives the common voltage Vcom. Unlike in FIG. 2, the common electrode 270 may be provided in the lower panel 100. In this case, both electrodes 191 and 270 may be formed in a linear or bar shape.

The storage capacitor CST is a capacitor that assists the liquid crystal capacitor CLC. The storage capacitor CST is formed by overlapping a separate signal line (not shown) and the pixel electrode 191 provided on the lower panel 100, and common to the separate signal lines. A predetermined voltage such as voltage Vcom is applied. However, the storage capacitor CST may be formed by the pixel electrode 191 overlapping the front gate line directly above the insulator.

In order to implement color display, each pixel PX uniquely displays one of a plurality of primary colors (spatial division) or alternately displays a plurality of primary colors (time division), so that the spatial In time, the desired color is indicated. Examples of the primary colors include three primary colors including red, green, and blue. FIG. 2 shows an example of spatial division in which each pixel PX includes a color filter 230 representing one color of the primary colors in a corresponding region facing the pixel electrode 191 in the upper panel 200. have. Alternatively, the color filter 230 may be formed above or below the pixel electrode 191 of the lower panel 100.

At least one 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 display panel unit 300.

Each pixel PX of the organic light emitting diode display includes a switching transistor (not shown) connected to the display signal lines G1 -Gn and D1 -Dm, a driving transistor (not shown), and a storage capacitor (not shown) connected thereto. Not shown), and an organic light emitting diode (OLED) (not shown). The light emitting diode includes an anode electrode (not shown) and a cathode electrode (not shown) and an organic light emitting member (not shown) therebetween.

Referring back to FIG. 1, the gray signal generator 800 generates a plurality of gray signals related to the transmittance of the pixel PX. The gray level signal generator 800 for the liquid crystal display generates two gray level voltages each having a positive value and a negative value with respect to the common voltage Vcom.

The gate driver 400 is connected to the gate lines G1 -Gn of the display panel unit 300 and has a gate signal having two values equal to the gate on voltage Von and the gate off voltage Voff, respectively. Applied to Gn). The gate driver 400 is integrated in the display panel 300 and includes a plurality of driving circuits (not shown). Each driving circuit of the gate driver 400 is connected to one gate line G1 -Gn and includes a plurality of N-type, P-type, and complementary polysilicon thin film transistors.

The data driver 500 is connected to the data lines D1-Dm of the display panel 300 and selects a gray voltage from the gray signal generator 800 and applies the data voltage to the data lines D1-Dm as a data voltage. . Like the gate driver 400, the data driver 500 is integrated in the display panel 300 and includes a plurality of driving circuits (not shown). Each driving circuit of the data driver 500 is connected to one data line D1 -Dm and includes a plurality of N-type, P-type, and complementary polysilicon thin film transistors.

However, the gate driver 400 or the data driver 500 may be mounted on the display panel 300 in the form of one or more integrated circuit (IC) chips or mounted on the flexible printed circuit film attached to the display panel 300. Can be.

The driving units 400 and 500 are positioned in the peripheral area PA positioned outside the display area DA in the display panel 300.

The signal controller 600 controls the gate driver 400, the data driver 500, and the like, and may be mounted on a printed circuit board (PCB).

Next, the detailed structure of the liquid crystal display according to the exemplary embodiment shown in FIGS. 1 and 2 will be described in detail with reference to FIGS. 3 and 4.

3 is a perspective view of a conventional liquid crystal display, and FIG. 4 is a perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIG. 4, the liquid crystal display according to the present exemplary embodiment includes a thin film transistor array panel 100, a common electrode display panel 200, a liquid crystal layer 3 interposed therebetween, and both display panels 100 and 200. And a sealing material 311 to be bonded.

As shown in FIG. 4, the liquid crystal layer 3 may be aligned in a vertical alignment method or a twisted nematic alignment method, and may have an arrangement that is symmetrically bent with respect to the center plane of the two display panels 100 and 200.

The thin film transistor array panel 100 is divided into a display area DA1, a non-display area NDA1 located outside the display area DA1, and a peripheral area PA located outside the non-display area NDA1. The display area DA1, the non-display area NDA1, and the peripheral area PA are separated, and the sealing material 311 is disposed to fix the thin film transistor array panel 100 and the common electrode display panel 200 and to confine the liquid crystal. .

In general, the sealing material 311 may be formed in a matrix form of the thin film transistor array panel 100 by using a seal print method using a screen mask and a drop method using a seal dispenser. The coating is performed so as to surround the arranged pixels PX.

In the method of applying the sealing material 311, the dropping method is to form the sealing material 311 on the thin film transistor array panel 100 in a moving direction of a support plate (not shown) supporting the thin film transistor array panel 100. When the sealing material 311 is formed through this dropping method, the line of the sealing material 311 is curved at the corner of the thin film transistor array panel 100.

As a result, the margin between the pixel electrode 191 arranged on the thin film transistor array panel 100 and the sealing material 311 is reduced, and as shown in FIG. 3, the pixel PX of the display area DA2 is conventionally used. The epoxy resin contained in the sealing material 312 overlaps the vertices of the dummy pixels and the sealing material 312 which are present at the outermost portions of the non-display area NDA2 arranged in parallel with each other in a rectangular shape. Penetration into the dummy pixel of the area NDA2 and the pixel of the display area DA2 caused the liquid crystal arrangement of the liquid crystal layer 3 to be poor, thereby deteriorating the reliability of the liquid crystal display device.

In order to prevent this, in the present invention, as shown in FIG. 4, the plurality of dummy pixels of the non-display area NDA1 positioned at the corner of the display area DA1 have a stepped structure.

As a result, a margin of 100 μm or more can be ensured between the sealing material 311 that exists in a curved shape at the corners of the display area DA1 and the non-display area NDA1 and the dummy pixels of the non-display area NDA1.

Therefore, the phenomenon in which the sealing material 311 and the pixel PX overlap each other may be prevented, thereby improving reliability of the liquid crystal display.

The liquid crystal display according to the present invention forms a corner portion of the non-display area in a stepped structure to sufficiently secure a margin between the sealing material having a curved shape and the dummy pixel of the non-display area to be 100 μm or more so that the epoxy resin of the sealing material By preventing penetration into the layer, the reliability of the liquid crystal display device can be improved.

Although 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 the invention.

Claims (4)

A first display panel having a plurality of pixels and dummy pixels, A second display panel facing the first display panel, The sealing material is adhered to the first and second display panels, and the corner portion is curved. Including; The dummy pixel surrounded by the sealing material and adjacent to the corner of the sealing material has a stepped structure. In claim 1, The first display panel is divided into a display area, a non-display area, and a peripheral area. In claim 2, And the non-display area is comprised of the dummy pixels. In claim 1, And a gap between the dummy pixel and the sealing material is 100 μm or more.

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