KR20060098536A - Fringe field switching mode liquid crystal display - Google Patents

Abstract

The present invention discloses a fringe field switching mode liquid crystal display device capable of improving the aperture ratio. In an exemplary embodiment of the present invention, a plurality of gate bus lines and data bus lines are arranged in a cross-section to define unit pixels in a display area, and a thin film transistor is disposed near an intersection point of the gate bus line and a data bus line. An upper substrate having a color filter corresponding to each unit pixel is a lower substrate having a structure in which a pixel electrode having a plate shape made of ITO and a counter electrode made of ITO and having an slit shape are overlapped under an insulating film. In a fringe field switching mode liquid crystal display device configured to be bonded to each other through a layer, a common bus line is formed outside the display area so as to be parallel to the data bus line, and the counter electrodes of the unit pixels are adjacent to each other. A display area interconnected with the counter electrode of the unit pixel A counter electrode disposed on the edge is electrically connected to the common bus line formed outside the display region.

Description

Fringe field switching mode liquid crystal display {FRINGE FIELD SWITCHING MODE LIQUID CRYSTAL DISPLAY}

1 is a plan view for explaining a conventional fringe field switching mode liquid crystal display device.

2 is a plan view illustrating a fringe field switching mode liquid crystal display device according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

30: lower substrate 31: gate bus line

32 common bus line 35 pixel electrode

36: data bus line 38: counter electrode

The present invention relates to a liquid crystal display device, and more particularly, to a fringe field switching mode liquid crystal display device that can improve the aperture ratio.

In general, the high aperture ratio and high transmittance liquid crystal display (Fringe field switching mode LCD) is proposed to improve the low aperture ratio and transmittance of the general IPS mode liquid crystal display, which is filed in Korean Patent Application No. 98-9243. There is a bar.

Such a high aperture ratio and high transmittance liquid crystal display device forms a counter electrode and a pixel electrode with a transparent conductor, and forms a gap between the counter electrode and the pixel electrode to be smaller than a gap between the upper and lower substrates, thereby forming a fringe field on the counter electrode and the pixel electrode. fringe fields are formed.

This fringe field switching mode liquid crystal display is shown in FIG.

As shown in FIG. 1, the gate bus line 11 extends in the x direction on the lower substrate 10, and the data bus line 16 extends in the y direction to define a unit pixel space. Thin film transistors (TFTs) are disposed near intersections of the gate bus line 11 and the data bus line 16. In addition, a common signal line 11a extends in parallel with the gate bus line 11 between a pair of neighboring gate bus lines 11. The pixel electrode 15 is formed of a transparent material in the unit pixel space, respectively. The counter electrode 18 overlaps the pixel electrode 15, and the counter electrode 18 is formed of a transparent material and extends in parallel with the data bus line 16 to connect several branches to one end of the branch. And a bar 18b which contacts the common signal line. At this time, the other end of the branch 18a may also be connected by another bar 18c.

In addition, a passivation layer (not shown) is deposited on the resultant material on which the data bus line 16 and the pixel electrode 15 are formed, and the passivation layer and the gate insulating layer (not shown) are etched to expose the surface of the lower common signal line 11a. As a result, contact holes are formed.

However, the fringe field switching mode liquid crystal display device forms a contact hole by etching the passivation layer and the gate insulating layer to expose the lower surface of the common signal line in order to prevent short between the counter electrode and the data bus line. Since the gate insulating film is thick, it is difficult to etch the protective film and the gate insulating film. In addition, when the contact hole is etched, liquid crystal alignment unevenness is generated around the contact hole, thereby reducing the transmittance and decreasing the transmittance at the common electrode part.

Accordingly, an object of the present invention is to provide a fringe field switching mode liquid crystal display device capable of improving the aperture ratio, which is devised to solve the above problems.

In order to achieve the above object, in the present invention, a plurality of gate bus lines and data bus lines are arranged in an intersecting manner to define unit pixels in a display area, and a thin film transistor is disposed near an intersection point of the gate bus lines and a data bus line. In the unit pixel, a lower substrate having a structure in which a pixel electrode made of ITO and a counter electrode made of ITO and a counter electrode made of ITO and having a slit shape are arranged to overlap each other under an insulating film has a color filter corresponding to each unit pixel. In a fringe field switching mode liquid crystal display device which is formed by being bonded to an upper substrate and an intervening liquid crystal layer, a common bus line is formed on the outside of the display area so as to be parallel to the data bus line. The counter electrode is mutual with the counter electrode of the neighboring unit pixel. The counter electrode, which is disposed at an edge of the display area, is electrically connected to a common bus line formed outside the display area.

Here, the space | interval between the said counter electrodes shall be 1-8 micrometers or less.

The interval between the counter electrode and the pixel electrode is 1 μm or more.

(Example)

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

2 is a plan view of a fringe field switching mode liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the gate bus line 31 extends in the x direction of the lower substrate 30, and the data bus line 36 extends in the y direction perpendicular to the gate bus line 31. Thus, a rectangular unit pixel space is defined in the display area. In this case, the gate bus line 31 is deposited as an aluminum-based metal film having excellent conductivity. Thin film transistors TFT are disposed near intersections of the gate bus line 31 and the data bus line 36. The common bus line 32 is formed outside the display area so as to be parallel to the data bus line 36.

In the unit pixel space, a pixel electrode 35 having a plate shape and a counter electrode 38 having a slit shape are formed under a gate insulating film (not shown). In this case, the pixel electrode 35 and the counter electrode 38 are each formed of a transparent material. Here, the interval between the counter electrodes is 1 to 8 µm or less, and the interval between the counter electrode and the pixel electrode is formed to 1 µm or more.

In addition, the counter electrode 38 is formed to overlap the pixel electrode 35, and the counter electrode 38 of the unit pixel is connected to the counter electrode 38 of the neighboring unit pixel and is connected to the edge of the display area. The disposed counter electrode 38 is electrically connected to the common bus line 32.

Here, the pixel electrode 35 and the counter electrode 38 are formed to be smaller than the cell gap (distance between the upper and lower substrates) so that the fringe field can be formed between the two electrodes, and the line width of the counter electrode and the pixel electrode is The fringe field is formed so that the liquid crystal molecules on the electrode can be sufficiently moved.

In the present invention, the pixel electrode is formed in a plate form, but the pixel electrode may be formed in a slit form.

In the present invention, the description of the alignment film, the polarizing plate, and the liquid crystal is omitted, but they are the same as in the conventional fringe field switching mode liquid crystal display device.

In the above, the present invention has been described with reference to some examples, but the present invention is not limited thereto, and those skilled in the art may make many modifications and variations without departing from the spirit of the present invention. It will be appreciated.

As described above, the present invention provides a contact in which a counter electrode of each unit pixel electrode is connected to a counter electrode of a neighboring unit pixel, and is connected to a common electrode on the pixel electrode by contacting a common bus line disposed at an edge of the display area. Unlike the conventional process of forming the hole, it is not necessary to form a contact hole on the pixel electrode, it is possible to prevent the liquid crystal alignment unevenness around the contact hole due to the contact hole etching to improve the aperture ratio.

In addition, by removing the common electrode connected to the counter electrode in the unit pixel space, the aperture ratio may be improved to improve transmittance.

Claims (3)

A plurality of gate bus lines and data bus lines intersect to limit unit pixels in a display area. A thin film transistor is disposed near an intersection point of the gate bus line and a data bus line, and a plate is formed of ITO in the unit pixel. A lower substrate having a structure in which a pixel electrode having a shape and an ITO and a counter electrode having a slit shape are arranged overlapping under an insulating film is interposed between an upper substrate having a color filter and a liquid crystal layer corresponding to each unit pixel. In the configured fringe field switching mode liquid crystal display device, A common bus line is formed outside the display area so as to be parallel to the data bus line, and the counter electrode of each unit pixel is connected to the counter electrode of a neighboring unit pixel, and disposed at an edge of the display area. And a counter electrode is electrically connected to a common bus line formed outside the display area. The fringe field switching mode liquid crystal display device according to claim 1, wherein a distance between the counter electrodes is 1 to 8 mu m or less. The fringe field switching mode liquid crystal display device according to claim 1, wherein a distance between the counter electrode and the pixel electrode is 1 µm or more.

Images