KR101537677B1 - Transverse electric field mode liquid crystal display element - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transverse electric field mode liquid crystal display element, A plurality of gate lines and a plurality of common electrode lines formed on the first substrate; A plurality of data lines crossing each of the plurality of gate lines to define a plurality of pixel regions; A thin film transistor formed at a point crossing the gate line and the data line; A pixel electrode electrically connected to the thin film transistor provided in the first and second pixel regions of the plurality of pixel regions and having a plurality of first pixel electrode branches arranged in a first direction; A common electrode connected to the plurality of first common electrode branches in a first direction; And a plurality of second pixel electrode branches electrically connected to the thin film transistors provided in the third and fourth pixel regions adjacent to the first and second pixel regions among the plurality of pixel regions, A common electrode electrically connected to the common electrode line and having a plurality of second common electrode branches divided in a second direction; A color filter layer formed on the second substrate; And a liquid crystal layer formed between the first substrate and the second substrate.

A common electrode, a domain, a dot, a sub-dot, a pixel electrode, a branch,

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display (LCD)

More particularly, the present invention relates to a liquid crystal display (LCD) device, and more particularly, to a liquid crystal display device, in which two adjacent pixels instead of a one by one pixel arrangement have pixel electrodes and common electrodes arranged in a first direction, A two-by-two pixel arrangement structure in which a pixel electrode and a common electrode are arranged in a direction of a liquid crystal display (LCD).

2. Description of the Related Art In recent years, various portable electronic devices such as a mobile phone, a PDA, and a notebook computer have been developed. Accordingly, there is an increasing demand for a flat panel display device for a light and small-sized flat panel display device.

Among these flat panel display devices, liquid crystal display (LCD), plasma display panel (PDP), field emission display (FED) and vacuum fluorescent display (VFD) have been actively studied. Among them, Due to its implementation, liquid crystal displays (LCDs) are now in the limelight.

A conventional liquid crystal display device implements an image by adjusting the light transmittance of a liquid crystal using an electric field. To this end, a liquid crystal display device includes a liquid crystal panel in which pixels are arranged in a matrix form, and a driving circuit for driving the liquid crystal panel.

The liquid crystal display element of the conventional transverse mode will be described with reference to FIGS. 1 to 3. FIG.

1 is a plan view schematically showing a liquid crystal display element of a transverse electric field mode according to the prior art.

FIG. 2A is a plan view of a one by one pixel arrangement of a liquid crystal display element in a transverse electric field mode according to the related art, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one dot pattern.

FIG. 2B is a schematic diagram showing an operating state of each domain when three domains in FIG. 2A are formed into one dot pattern. FIG.

FIG. 3A is a two-by-two pixel arrangement plan view of a liquid crystal display element in a transverse electric field mode according to the related art, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one dot pattern.

FIG. 3B is a schematic diagram showing an operating state of each domain when one domain of FIG. 3A is composed of one dot pattern. FIG.

Referring to FIG. 1, a liquid crystal display device according to the related art includes a gate line 13 and a data line 21 arranged on the first substrate of the liquid crystal panel so as to cross the gate line 13, A thin film transistor (TFT) T, which is a switching element, is formed in a crossing region between the data lines 21 and 13. At this time, the thin film transistor T includes a gate electrode (not shown) extending in parallel with the data line 21 in the gate line 13, a source electrode 23 A drain electrode 25 spaced apart from the source electrode 23 by a channel length, and an active layer (not shown).

Each of the pixels of the liquid crystal panel has a common electrode line 15 spaced apart from the gate line 13 and the data line 21 by a predetermined distance.

Each of the pixels of the liquid crystal panel is provided with pixel electrodes 27 divided into a plurality of pixel electrode branches 27a and 27b spaced at regular intervals in first and second directions, The common electrode 29 is divided into a plurality of common electrode branches 29a and 29b spaced apart from each other by a predetermined distance in the second direction and parallel to the pixel electrode 27. [

Here, the pixel has a one domain structure, and the pixel electrode 27 and the common electrode 29 are disposed one by one. In other words, in the first pixel D1, the plurality of branches 27a of the pixel electrode 27 are arranged in the first direction, and the plurality of branches 29a of the common electrode 29 are also arranged in the first direction Respectively.

On the other hand, in the second pixel D2, the plurality of branches 27b of the pixel electrode 27 are arranged in the second direction, correspondingly, the plurality of branches 29b of the common electrode 29 are also arranged in the second direction Respectively.

The pixel electrode 27 is electrically connected to the drain electrode 25 of the thin film transistor T through a contact hole (not shown), and the common electrode 29 is electrically connected to another contact hole (not shown) And is electrically connected to the common electrode line 15. [

The pixel electrode 27 receives a data signal from the source / drain electrodes 23 and 25 of the thin film transistor T as a switching element and forms a transverse electric field on the first substrate together with the common electrode 29.

A gate electrode (not shown) of the thin film transistor T is connected to the gate line 13 so that a data signal is applied to the pixel electrodes 27 for one line. Accordingly, the liquid crystal display element displays an image by adjusting the light transmittance of the liquid crystal layer (not shown) by an electric field applied between the pixel electrode 27 and the common electrode 29 in accordance with the data signal supplied for each pixel.

Although not shown in the drawing, a color filter layer is formed on the second substrate, and a liquid crystal layer is formed in a space between the first substrate and the second substrate.

Referring to FIG. 2A, the liquid crystal display element is disposed adjacent to three dot patterns D1, D2, and D1 and three dot patterns D2, D1, and D2.

Referring to FIG. 2B, when three domains D1, D2, and D1 and three domains D2, D1, and D2 are arranged adjacent to each other while forming one dot pattern, The three domains of other adjacent dots are turned off.

Therefore, since the three domains D1, D2, and D1 are turned on and only the other three domains D2, D1, and D2 are turned off, a left-right color difference and a luminance difference are generated.

Referring to FIG. 3A, in the liquid crystal display device, one domain D1 and one domain D2 are disposed adjacent to each other while forming one sub-one dot pattern.

Referring to FIG. 3B, when one domain D1 and one domain D2 are arranged adjacent to each other while forming one sub-1-dot pattern, one domain of one dot is turned on and adjacent And one domain of the other dot is configured to be turned off.

Therefore, one domain (D2) of the sub-one dot is turned on, but the other one domain (D1) is turned off, resulting in a color difference and luminance difference.

However, the transverse electric field mode liquid crystal display device according to the related art has the following problems.

In the transverse electric field liquid crystal display device according to the related art, when three domains are constituted by one dot pattern, three domains constituting one dot pattern are continuously turned on, and the other three domains constituting the other dot pattern Since the domain is continuously turned off, a difference in color tonality and a difference in luminance occur.

Even when one domain is constituted by one sub-dot pattern, one domain in the second direction of the sub-one dot is turned on, but the other one domain in the first direction is continuously turned off, .

Therefore, when one pixel is constituted by one domain, it is possible to obtain a pixel having a pixel electrode and a common electrode in a first direction and a pixel electrode and a common electrode in a second direction different from the first direction, The conventional liquid crystal display device constructed alternately can not maximize the high aperture ratio effect because the difference in color tone and luminance is generated.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a liquid crystal display device in which pixel electrodes and common electrodes of two adjacent pixels are arranged in a first direction, A liquid crystal display element of a transverse electric field mode capable of ensuring a high aperture ratio along with an increase in luminance by improving a color tilt by applying a pixel arrangement structure in which a pixel electrode and a common electrode of the pixels are arranged in a second direction different from the first direction .

According to an aspect of the present invention, there is provided a transverse electric field mode liquid crystal display device including a first substrate and a second substrate; A plurality of gate lines and a plurality of common electrode lines formed on the first substrate; A plurality of data lines crossing each of the plurality of gate lines to define a plurality of pixel regions; A thin film transistor formed at a point crossing the gate line and the data line; A pixel electrode electrically connected to the thin film transistor provided in the first and second pixel regions of the plurality of pixel regions and having a plurality of first pixel electrode branches arranged in a first direction; A common electrode connected to the plurality of first common electrode branches in a first direction; And a plurality of second pixel electrode branches electrically connected to the thin film transistors provided in the third and fourth pixel regions adjacent to the first and second pixel regions among the plurality of pixel regions, A common electrode electrically connected to the common electrode line and having a plurality of second common electrode branches divided in a second direction; A color filter layer formed on the second substrate; And a liquid crystal layer formed between the first substrate and the second substrate.

The transverse electric field mode liquid crystal display device according to the present invention has the following effects.

In the transverse electric field mode liquid crystal display device according to the present invention, the same three domains are turned on and off as in the conventional method, but the three color domains are turned on or off alternately, thereby preventing the difference in color tone.

Further, in the transverse electric field mode liquid crystal display element according to the present invention, since the domain in the first direction and the domain in the second direction are alternately turned on and the domain in the first direction and the domain in the second direction are also turned off alternately, No difference will occur.

Therefore, the transverse electric field mode liquid crystal display element according to the present invention can maximize the increase of the aperture ratio because no color difference and luminance difference are generated.

Hereinafter, a transverse electric field mode liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a plan view schematically showing a liquid crystal display element of a transverse electric field mode according to the present invention.

4, the transverse electric field mode liquid crystal display element according to the present invention includes a gate line 113 and a data line 121 arranged on the first substrate of the liquid crystal panel so as to cross the gate line 113 and the data line 121, A thin film transistor (TFT) T, which is a switching element, is formed in a region where the line 113 and the data line 121 cross each other. The thin film transistor T includes a gate electrode (not shown) extending in parallel with the data line 121 in the gate line 113, a source electrode 123 extending in the gate line 113, A drain electrode 125 spaced apart from the source electrode 123 by a channel length, and an active layer (not shown).

Each of the pixels of the liquid crystal panel has a common electrode line 115 spaced apart from the gate line 113 and the data line 121 by a predetermined distance.

Each of the pixels of the liquid crystal panel is provided with pixel electrodes 127 divided into a first and second pixel electrode branches 127a and 127b spaced apart from each other by a predetermined distance in a first direction and a second direction, The common electrode 129 is divided into a plurality of first and second common electrode branches 129a and 129b spaced apart in a first direction and a second direction and parallel to the pixel electrode 127. [

Here, the pixel has a one domain structure, and the pixel electrode 127 and the common electrode 129 are arranged in two by tow.

The first and second pixels D1 and D1 forming one pair are adjacent to each other in the extending direction of the gate line and the plurality of first pixel electrode branches 127a of the pixel electrode 127 are arranged in the first direction And correspondingly, the plurality of first common electrode branches 129a of the common electrode 129 are also arranged in the first direction.

On the other hand, the third and fourth pixels D2 and D2 forming another pair are adjacent to each other in the extending direction of the gate line, and the plurality of second pixel electrode branches 127b of the pixel electrode 127 are adjacent to the first And a plurality of second common electrode branches 129b of the common electrode 129 are also arranged in the second direction.

Accordingly, the plurality of pixels may include first and second pixels D1 and D1 having a pixel electrode 127 and a common electrode 129 arranged in a first direction, and third and fourth pixels D2 and D3 arranged in a second direction, D2 are alternately arranged in left and right directions.

The pixel electrode 127 is electrically connected to the drain electrode 125 of the thin film transistor T through a contact hole (not shown), and the common electrode 129 is electrically connected to another contact hole (not shown) And is electrically connected to the common electrode line 115 through the common electrode line 115.

The pixel electrode 127 receives a data signal from the source / drain electrodes 123 and 125 of the thin film transistor T as a switching element and forms a transverse electric field on the first substrate together with the common electrode 129.

A gate electrode (not shown) of the thin film transistor T is connected to the gate line 113 so that a data signal is applied to the pixel electrodes 127 for one line. Accordingly, the liquid crystal display element displays an image by adjusting the light transmittance of the liquid crystal layer (not shown) by an electric field applied between the pixel electrode 127 and the common electrode 129 according to a data signal supplied for each pixel.

Although not shown in the drawing, a color filter layer is formed on the second substrate, and a liquid crystal layer is formed in a space between the first substrate and the second substrate.

FIG. 5A is a plan view of a one by one pixel layout of a liquid crystal display element in a transverse electric field mode according to the present invention, in which a first domain D1 and a second domain D2 are arranged side by side, Is defined as one dot pattern.

FIG. 5B is a schematic diagram showing an operating state of each domain when three domains in FIG. 5A are formed into one dot pattern. FIG.

FIG. 6A is a two-by-two pixel arrangement plan view of a liquid crystal display element in a transverse electric field mode according to the present invention, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one sub-one-dot pattern.

FIG. 6B is a schematic diagram showing an operating state of each domain when one domain of FIG. 6A is formed into one sub-one dot pattern. FIG.

Referring to FIG. 5A, a liquid crystal display according to an exemplary embodiment of the present invention includes three domains D1, D1, D2, D2, D1, D1, D2, D2, D1, D1, D2, And are arranged alternately and repeatedly while constituting one dot pattern.

In other words, the first and second pixels D1 and D1, which form one pair, are arranged such that a plurality of first pixel electrode branches 127a of the pixel electrode 127 are arranged in the first direction, The plurality of first common electrode branches 129a of the plurality of first common electrode branches 129 are also arranged in the first direction.

The third and fourth pixels D2 and D2 constituting the other pair are arranged in a second direction corresponding to the first direction and corresponding to a plurality of pixel electrode branches 127b of the pixel electrode 127 And the plurality of second common electrode branches 129b of the common electrode 129 are also arranged in the second direction.

Therefore, when three domains constitute one dot pattern, the three domains are (D1, D1, D2), (D2, D1, D1), (D2, D2, D1) ). When three domains are constituted by one dot pattern, the three domains are different from the other domains D1, D1, D2, D2, D1, D1, D2, D2, , D2, and D2.

5B, each of the three domains D1, D1, D2, D2, D1, D1, D2, D2, D1, D1, D2, , Three domains of one dot are turned on and three domains of other adjacent dots are turned off.

Therefore, as shown in FIGS. 5A and 5D, three domains D1, D1, and D2 constituting one dot are turned on, and three domains D1, D1, and D2 adjacent to the three domains D1, (D2, D1, D1) are turned off.

The three domains D2, D1 and D1 and the three adjacent domains D2, D2 and D1 are turned on and the three domains D1, D2 and D2 adjacent to the three domains D2, D1 and D1 are turned off. do.

As described above, according to the present invention, since the same three domains are turned on and off as in the conventional art, the three domains of different pairs are turned on and off, thereby preventing the occurrence of right and left color differences.

On the other hand, referring to FIG. 6A, one liquid crystal display element is disposed adjacent to one domain D1 and one domain D2 while forming one sub-one dot pattern. That is, when one domain forms one sub-1-dot pattern, one domain has a structure arranged in the order of (D1), (D1), (D2), and (D2).

Referring to FIG. 6B, when one domain D1 and one domain D2 are arranged adjacent to each other while forming one sub-1 dot pattern, one domain of one dot is turned on, One domain of the sub-one-dot pattern is turned off.

In this manner, when one sub-dot pattern is constituted by one domain, the domain D1 in the first direction and the domain D2 in the second direction are alternately turned on as shown in Figs. 6A and 6B, The domain D1 of the first direction and the domain D2 of the second direction are also turned off alternately.

Therefore, in the conventional method, only one directional domain, that is, D1 or D2, is turned on in the specific pattern such as the sub 1-dot pattern, so that the left and right chromaticity and luminance difference occur. However, as shown in FIGS. 6A and 6B, And the domain D2 in the second direction are alternately turned on and the domain D1 in the first direction and the domain D2 in the second direction are also turned off alternately. Moreover, it can lead to an increase in the aperture ratio, which is an advantage of one domain structure.

It is to be noted that the technical spirit of the present invention has been specifically described in accordance with the above preferred embodiment, but it should be noted that the above-mentioned embodiments are intended to be illustrative and not restrictive. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

1 is a plan view schematically showing a liquid crystal display element of a transverse electric field mode according to the prior art.

FIG. 2A is a plan view of a one by one pixel arrangement of a liquid crystal display element in a transverse electric field mode according to the related art, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one dot pattern.

FIG. 2B is a schematic diagram showing an operating state of each domain when three domains in FIG. 2A are formed into one dot pattern. FIG.

FIG. 3A is a two-by-two pixel arrangement plan view of a liquid crystal display element in a transverse electric field mode according to the related art, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one dot pattern.

FIG. 3B is a schematic diagram showing an operating state of each domain when one domain of FIG. 3A is composed of one dot pattern. FIG.

4 is a plan view schematically showing a liquid crystal display element of a transverse electric field mode according to the present invention.

FIG. 5A is a plan view of a one by one pixel layout of a liquid crystal display element in a transverse electric field mode according to the present invention, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one dot pattern.

FIG. 5B is a schematic diagram showing an operating state of each domain when three domains in FIG. 5A are formed into one dot pattern. FIG.

FIG. 6A is a two-by-two pixel arrangement plan view of a liquid crystal display element in a transverse electric field mode according to the present invention, in which a domain D1 in a first direction and a domain D2 in a second direction are arranged side by side, Is defined as one sub-one-dot pattern.

FIG. 6B is a schematic diagram showing an operating state of each domain when one domain of FIG. 6A is formed into one sub-one dot pattern. FIG.

*** Description of major parts of drawing ***

113: gate line 115: common electrode line

121: Data line 123: Drain electrode

125: source electrode 127: pixel electrode

127a, 127b: first and second pixel electrode branches

129: common electrodes 129a and 129b: first and second common electrode branches

T: thin film transistor D1, D2: domain (pixel)

Claims (4)

A first substrate and a second substrate; A plurality of gate lines and a plurality of common electrode lines formed on the first substrate; A plurality of data lines crossing each of the plurality of gate lines to define a plurality of pixel regions; A thin film transistor formed at a point crossing the gate line and the data line; First and second pixel regions adjacent to each other in the extending direction of the gate lines among the plurality of pixel regions; A pixel electrode electrically connected to the thin film transistors provided in the first and second pixel regions and having a plurality of first pixel electrode branches divided in a first direction; A common electrode in which a common electrode branch is divided in a first direction; A third and fourth pixel regions adjacent to each other in the extending direction of the gate line and the extending direction of the data line with respect to the first and second pixel regions of the plurality of pixel regions and extending in the extending direction of the gate line; Pixel electrodes electrically connected to the thin film transistors provided in the third and fourth pixel regions and having a plurality of second pixel electrode branches arranged in a second direction different from the first direction; A common electrode connected to the plurality of second common electrode branches in a second direction; A color filter layer formed on the second substrate; And And a liquid crystal layer formed between the first substrate and the second substrate, Wherein the three pixel regions of the pixel regions have one dot pattern. The transverse electric field mode liquid crystal display element according to claim 1, wherein the pixel electrode is electrically connected to a drain electrode constituting the thin film transistor. The display device of claim 1, further comprising first and second pixel regions in which a first pixel electrode branch and a first common electrode branch are arranged in the first direction, and a second pixel electrode branch and a second common electrode branch in a second direction And the third and fourth pixel regions are alternately repeated. The liquid crystal display device according to claim 1, wherein when the three pixel regions are constituted by one dot pattern, two pixels arranged in the first direction and a pixel arranged in the second direction, One pixel arranged in the second direction and the two pixels arranged in the first direction constitute the second dot pattern and two pixels arranged in the second direction are arranged in the first direction One pixel constituting the third dot pattern, and one pixel arranged in the first direction and two pixels arranged in the second direction form a fourth dot pattern, which are alternately repeated and arranged A liquid crystal display element of a transverse electric field mode.

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