KR101980772B1 - 2 Pixel 2 Domain Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display having a two-pixel two-domain structure for reducing the luminance difference between pixels and improving image quality and transmittance. A plurality of data lines arranged in a second direction perpendicular to the first direction to define a plurality of trapezoidal pixel regions; And a plurality of thin film transistors formed at intersections of the gate wirings and the data wirings, wherein each of the eight trapezoidal pixels has a pixel unit structure, and the eight pixel units have four different It is characterized by having a pixel shape.

Description

 [0001] The present invention relates to a two-pixel two-domain liquid crystal display device,

The present invention relates to a liquid crystal display (LCD), and more particularly, to a liquid crystal display device for improving image quality and transmittance by reducing a luminance difference between pixels in a 2 pixel 2 domain structure.

In recent years, as the information age has come to a full-fledged information age, a display field for visually expressing electrical information signals has been rapidly developed. In response to this, various flat panel display devices having excellent performance of thinning, light weight, Flat Display Device) has been developed to replace CRT (Cathode Ray Tube).

Specific examples of such flat panel display devices include a liquid crystal display device (LCD), a field emission display device (FED), and an electro luminescence display device (ELD) These flat panel display panels, which commonly implement images, are indispensable components. The flat panel display panel has a structure in which a pair of transparent insulating substrates are bonded together with a unique light-emitting or polarizing material layer interposed therebetween.

In a liquid crystal display device, an image is displayed by adjusting the light transmittance of a liquid crystal using an electric field. To this end, the image display apparatus includes a display panel having a liquid crystal cell, a backlight unit for irradiating the display panel with light, and a drive circuit for driving the liquid crystal cell.

The display panel is formed such that a plurality of gate lines and a plurality of data lines intersect to define a plurality of unit pixel regions. At this time, each pixel region includes a thin film transistor array substrate and a color filter array substrate facing each other, a spacer positioned to maintain a constant cell gap between the two substrates, and a liquid crystal filled in the cell gap.

The thin film transistor array substrate includes gate lines and data lines, a thin film transistor formed as a switching element at each intersection of the gate lines and the data lines, a pixel electrode formed in a unit of a liquid crystal cell and connected to the thin film transistor, And an alignment film coated thereon. The gate lines and the data lines are supplied with signals from the driving circuits through respective pad portions.

The thin film transistor supplies a pixel voltage signal supplied to the data line in response to a scan signal supplied to the gate line.

The color filter array substrate includes color filters formed in units of liquid crystal cells, a black matrix for separating color filters and reflecting external light, a common electrode for supplying a reference voltage commonly to the liquid crystal cells, .

The thin film transistor substrate thus manufactured and the color filter array substrate are aligned by aligning each other, then the liquid crystal is injected and sealed.

In such a liquid crystal display device, a liquid crystal is driven by a vertical electric field between upper and lower sides between a common electrode and a pixel electrode, which is superior in terms of transmittance and aperture ratio but has a limited viewing angle characteristic. A liquid crystal display device of the lateral electric field type having a wide viewing angle characteristic has been proposed.

1 is a cross-sectional view showing a cross-section of a general transverse electric field type liquid crystal display device.

1, the first and second substrates 10 and 20 are spaced from each other in a state in which they are opposed to each other, and between the first and second substrates 10 and 20, The liquid crystal layer 30 is interposed. The common electrode 12 and the pixel electrode 14 are formed on the first substrate 10 so as to be spaced apart from each other. An in-plane field (IF) is formed between the common electrode 12 and the pixel electrode 14 when a voltage is applied and the liquid crystal molecules 32 of the liquid crystal layer 30 Are arranged in a direction parallel to the substrate, the viewing angle becomes wider.

For example, when the transverse electric field type liquid crystal display device is viewed from the front, it can be seen from the direction of about 80 to 85 degrees in the up / down / left / right direction.

2 is a plan view of a unit pixel of a general transverse electric field type liquid crystal display device.

2, a unit pixel of a transverse electric field type liquid crystal display device includes a gate line GL in a first direction and a data line DL in a second direction perpendicular to the first direction, A common line CL is formed so as to be spaced apart from the gate line GL in the first direction and a thin film transistor DL is formed at the intersection of the gate line GL and the data line DL T) is formed. A plurality of common electrodes 40 are branched in the second direction from the common line GL and are electrically connected to the drain electrodes of the thin film transistor T so as to be electrically connected to the common electrodes 40 in the second direction A plurality of pixel electrodes 42 are formed.

3 is a plan view of a conventional transverse electric field type liquid crystal display device having a 1 pixel 1 domain structure.

That is, in the conventional transverse electric field type liquid crystal display device of one pixel 1 domain structure, the unit cells as shown in Fig. 2 are arranged in a matrix form as shown in Fig.

In the conventional transverse electric field type liquid crystal display of the one pixel 1 domain structure, since there is only one domain in one unit pixel, the image quality due to the problem of color shift and gray inversion in the diagonal direction There was a problem that it was deteriorated.

In order to solve the above problems, a transverse electric field type liquid crystal display having a one-pixel-one-domain structure has been developed.

FIG. 4 is a plan view of a unit pixel of a conventional 1 pixel 2 domain structure, and FIG. 5 is a plan view of a conventional transverse electric field type liquid crystal display having a 1 pixel 2 domain structure.

4, the common electrode 40, the pixel electrode 42, and the data line DL are provided in the unit cell structure as shown in FIG. 2 so that one unit cell has two domains As shown in FIG. 5, the unit cells having the common electrode 40, the pixel electrode 42, and the data line DL are arranged in a matrix form.

 However, as shown in FIG. 5, even in the one pixel 2 domain structure, since the front line is generated in the central portion where the domains are connected, the panel transmittance is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a liquid crystal display device having a 2 pixel 2 domain structure for reducing image brightness and improving image quality and transmittance, .

According to an aspect of the present invention, there is provided a two-pixel two-domain liquid crystal display comprising: a plurality of gate lines arranged in a first direction; A plurality of data lines arranged in a second direction perpendicular to the first direction to define a plurality of trapezoidal pixel regions; And a plurality of thin film transistors formed at intersections of the gate wirings and the data wirings, wherein each of the eight trapezoidal pixels has a pixel unit structure, and the eight pixel units have four different It is characterized by having a pixel shape.

Here, the plurality of data wirings may have a structure in which the 4n-3th and 4n-1th data wirings have a linear shape, the 4n-2th and 4nth data wirings overlap with the gate wirings, And the (4n-2) -th data wiring and the (4n-1) -th data wiring have a bending structure in an opposite direction to each other.

A trapezoidal pixel electrode electrically connected to a drain electrode of the thin film transistor and formed in each pixel region, and a common electrode formed on the pixel electrode in common with the pixel electrode and having a plurality of slits insulated from the pixel electrode, .

And the angle between the pixel electrode and the common electrode is designed to be smaller than the main angle of the opening in the linear data line portion.

And the eight pixels of the trapezoidal shape are arranged to be symmetrical with respect to the X axis and the Y axis.

According to another aspect of the present invention, there is provided a two-pixel-two-domain liquid crystal display comprising: a plurality of gate lines arranged in a first direction; A plurality of data lines arranged in a second direction perpendicular to the first direction to define a plurality of trapezoidal pixel regions; A common wiring formed to be spaced apart from the gate wiring GL in the first direction; A plurality of thin film transistors formed at intersections of the gate wirings and the data wirings; A plurality of common electrodes branched in the second direction in the common wiring and formed in the pixel region; And a plurality of pixel electrodes electrically connected to a drain electrode of the thin film transistor and formed in a second direction between the common electrodes, wherein the eight pixels of the trapezoidal shape are configured to have a pixel unit structure, Another feature is that the constructed pixel unit has four differently shaped pixel shapes.

The two-pixel-two-domain liquid crystal display device according to the present invention has the following advantages.

In the present invention, eight unit pixels in a trapezoidal shape are configured to have a pixel unit structure and eight pixel units have four differently shaped pixel shapes, so that the opening shapes in the four pixel shapes are the same And the openings are symmetrically or rotationally arranged in the X-axis and the Y-axis, so that the difference in luminance between pixels can be minimized.

That is, the opening shape has a symmetrical structure of the pixel, the common electrode and the black matrix layer. Therefore, since a symmetrical structure is provided for each pixel in a region where light is transmitted, a luminance difference does not occur.

In the linear portion of the data wiring, the angle between the pixel electrode and the common electrode is designed to be slightly smaller than the main angle of the opening portion, so that vertical or oblique spots can be prevented.

1 is a cross-sectional view showing a cross section of a general transverse electric field type liquid crystal display device
2 is a plan view of a unit pixel of a general transverse electric field type liquid crystal display device
3 is a plan view of a conventional liquid crystal display device having a 1 pixel 1 domain structure
4 is a plan view of a unit pixel of a conventional 1 pixel 2 domain structure.
5 is a plan view of a conventional liquid crystal display device having a 1 pixel 2 domain structure
6 is a plan view of a liquid crystal display device having a 2-pixel 2 domain structure according to the present invention.
7 is a plan view of a unit pixel of a 2 pixel 2 domain structure according to the present invention.
8 is a cross-sectional view taken along the line II '
9 is a structural cross-sectional view of a unit pixel of a 2 pixel 2 domain structure according to another embodiment of the present invention

A two-pixel-two-domain liquid crystal display according to the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 6 is a plan view of a liquid crystal display device of a 2 pixel 2 domain structure according to the present invention, and FIG. 7 is a plan view of a unit pixel of a 2 pixel 2 domain structure according to the present invention And Fig. 8 is a cross-sectional view taken along the line II 'in Fig.

As shown in FIG. 6, a liquid crystal display device of a 2 pixel 2 domain structure according to the present invention is configured such that eight unit pixels of a trapezoidal shape have a pixel unit structure. The eight-pixel unit has four differently shaped pixel shapes.

6, a plurality of gate lines GL1, GL2, GL3, ... are arranged in a first direction, and a plurality of data lines GL1, GL2, GL3, ... in a second direction perpendicular to the first direction, (DL1, DL2, DL3, and DL4) are arranged to define a plurality of pixel regions.

At this time, the 4n-3th and 4n-1th data lines DL1 and DL3 have a linear shape and the 4n-2th and 4nth data lines DL2 and DL4 overlap with the gate line GL And the 4n-2th data line DL2 and the 4nth data line DL4 have a bending structure in the opposite direction to each other. Here, n is a natural number.

A thin film transistor T is formed at an intersection of each of the gate lines GL and the data line DL and is electrically connected to a drain electrode of the thin film transistor T, An electrode 56 is formed and a common electrode 58 having a plurality of slits is formed on the upper side of the pixel electrode in common to the entire pixel region.

Therefore, the four trapezoidal unit pixels 1, 2, 3 and 4 arranged on the upper side with respect to the gate line GL are arranged in different shapes, and the four trapezoidal unit pixels 1, 2, 3 and 4 arranged on the lower side with respect to the gate line GL The four trapezoidal unit pixels 3, 4, 1, and 2 are the same as the four trapezoidal unit pixels arranged on the upper side, but are arranged in different positions.

That is, the pixel 2 between the (4n-2) th and (4n-1) th data lines above the gate line GL has the pixel 1 between the And the unit pixels are arranged so as to be symmetrical with respect to the X-axis and the Y-axis about the gate wiring GL and the (4n-1) -th data wiring.

Accordingly, the opening shapes of the four pixel shapes are designed to be the same, and the openings are symmetrically or rotationally arranged in the X axis and the Y axis to minimize the luminance difference between the pixels.

That is, the opening shape has a symmetrical structure of the pixel, the common electrode and the black matrix layer. Therefore, since a symmetrical structure is provided for each pixel in a region where light is transmitted, a luminance difference does not occur.

A unit pixel configuration of a liquid crystal display device having a 2 pixel 2 domain structure according to the present invention having the above structure will now be described.

7 and 8, a gate line GL and a gate electrode 51 are formed on a substrate 50. A gate line GL and a gate electrode 51 are formed on a substrate 50 including the gate line GL and the gate electrode 51, A gate insulating film 52 is formed on the entire surface.

A semiconductor layer 53 is formed on the gate insulating film 52 on the gate electrode 51 and a source electrode 54 and a drain electrode 55 are formed on both sides of the semiconductor layer 53. [ The data line DL is formed in a direction perpendicular to the gate line GL.

A pixel electrode 56 is formed on the gate insulating layer in each pixel region so as to be connected to the drain electrode 55. An interlayer insulating layer 57 is formed on the entire surface of the substrate including the pixel electrode.

A common electrode 58 having a plurality of slits is formed on the interlayer insulating film 57. A protective film 59 is formed on the entire surface.

7, in the linear data lines (4n-3th and 4n-1th data lines) among the data lines DL, the angle between the pixel electrode 56 and the common electrode 58 Is designed to be smaller than the main angle.

The reason for this is that vertical lines or oblique lines can be seen because the foreground lines are seen in a straight line portion of the data line and the shapes of the foreground lines are different according to pixel shapes of other shapes. Therefore, in the linear portion of the data wiring, the angle between the pixel electrode and the common electrode is designed to be slightly smaller than the main angle of the opening portion.

6 to 8 illustrate a FFS (Fringe Field Switch) mode liquid crystal display device. However, the present invention is not limited to this. In a liquid crystal display of IPS (In Plane Switching) mode, Can be applied.

9 is a structural cross-sectional view of a unit cell of an IPS mode liquid crystal display device having a 2 pixel 2 domain structure according to the present invention.

In Fig. 9, the same layers as in Fig. 8 are given the same reference numerals.

2, a gate line GL is formed in a first direction, a data line DL is formed in a second direction perpendicular to the first direction, and a gate line GL is formed in the first direction The common lines CL are formed so as to be spaced apart from the common lines GL.

A plurality of common electrodes 58 are branched in the second direction from the common line GL and are electrically connected to the drain electrodes of the thin film transistor T so as to be electrically connected to the common electrodes 58 in the second direction A plurality of pixel electrodes 56 are formed.

That is, the pixel electrode 56 and the common electrode 58 are formed in the same layer. The unexplained reference numeral is a planarization insulating film 60.

The technical idea of the present invention has been specifically described according to the above preferred embodiments, but the above-mentioned embodiments are intended to be illustrative and not restrictive. In addition, it will be understood by those of ordinary skill in the art that various embodiments are possible within the scope of the technical idea of the present invention. Accordingly, the scope of the present invention should be determined by the claims rather than the examples described.

GL1, GL2, GL3: gate wiring DL1, DL2, DL3, DL4:
50: substrate 51: gate electrode
52: gate insulating film 53: semiconductor layer
54: source electrode 55: drain electrode
56: pixel electrode 57: interlayer insulating film
58: common electrode 59: protective film
60: planarization insulating film

Claims (9)

A plurality of gate lines arranged in a first direction;
A plurality of data lines arranged in a second direction perpendicular to the first direction to define a plurality of trapezoidal pixel regions;
A plurality of thin film transistors formed at intersections of the gate wirings and the data wirings;
A trapezoidal pixel electrode electrically connected to the drain electrode of the thin film transistor and formed in each pixel region; And
And a common electrode formed on the pixel electrode in common with the pixel region and formed with a plurality of slits insulated from the pixel electrode,
Eight of the trapezoidal-shaped pixels are configured to have a pixel unit structure, eight-pixel units have four differently shaped pixel shapes,
Wherein the plurality of data lines include:
The 4n-2 th data line and the 4n-1 th data line have a straight line shape, the 4n-2 th data line and the 4n th data line have a bent structure at a portion overlapping the gate line, The data lines have bending structures in opposite directions,
And the angle between the pixel electrode and the common electrode is designed to be smaller than the main angle of the opening in the linear data line portion. delete delete delete The method according to claim 1,
And the eight pixels of the trapezoidal shape are arranged to be symmetrical with respect to the X axis and the Y axis. A plurality of gate lines arranged in a first direction;
A plurality of data lines arranged in a second direction perpendicular to the first direction to define a plurality of trapezoidal pixel regions;
A common wiring formed to be spaced apart from the gate wiring GL in the first direction;
A plurality of thin film transistors formed at intersections of the gate wirings and the data wirings;
A plurality of common electrodes branched in the second direction in the common wiring and formed in the pixel region;
And a plurality of pixel electrodes electrically connected to the drain electrodes of the thin film transistors and formed in the second direction between the common electrodes,
Eight pixels in the trapezoidal shape are configured to have a pixel unit structure, eight pixel units have four differently shaped pixel shapes,
Wherein the plurality of data lines include:
The 4n-2 th data line and the 4n-1 th data line have a straight line shape, the 4n-2 th data line and the 4n th data line have a bent structure at a portion overlapping the gate line, The data lines have bending structures in opposite directions,
And the angle between the pixel electrode and the common electrode is designed to be smaller than the main angle of the opening in the linear data line portion. delete delete The method according to claim 6,
And the eight pixels of the trapezoidal shape are arranged to be symmetrical with respect to the X axis and the Y axis.

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