KR101760619B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device. A liquid crystal display device according to the present invention includes a first substrate including a crossing region where gate lines and data lines intersect and a pixel region defined by the gate lines and the data lines, And a liquid crystal layer between the first substrate and the second substrate, wherein the transparent metal film has a thickness of more than 1000 angstroms and 1700 angstroms or less so as to control the color coordinates of white light passing through the second substrate .

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

The present invention relates to a liquid crystal display device.

Recently, interest in information display has increased, and a demand for using portable information media has increased, and a light-weight flat panel display (FPD) that replaces a cathode ray tube (CRT) And research and commercialization are being carried out. Particularly, among such flat panel display devices, a liquid crystal display (LCD) is an apparatus for displaying an image using the optical anisotropy of a liquid crystal, and is excellent in resolution, color display and picture quality and is actively applied to a notebook or a desktop monitor have.

The liquid crystal display device generally includes a liquid crystal display panel for displaying an image using light transmittance of a liquid crystal, a backlight assembly disposed below the liquid crystal display panel and providing light to the liquid crystal display panel, back-light assembly.

The backlight assembly includes a light generating unit that generates light, and the light generating unit is generally equipped with a cold cathode fluorescent lamp (CCFL), a flat fluorescent lamp (FFL), a light emitting diode Emitting Diode, LED). Among the light generating units, the light emitting diode can be manufactured in the form of a chip, has high luminance and low power consumption characteristics, and is recently used as a light source of the backlight assembly.

The liquid crystal display panel includes an array substrate on which switching elements are formed, a color filter substrate on which color filters are formed, and a liquid crystal layer interposed between the array substrate and the color filter.

Generally, in a conventional color filter substrate, color filters having three colors of red, green, and blue are formed in one pixel, and a combination of red light, green light, and blue light transmitted through red, green, and blue color filters Represents a white light, and a desired color can be realized through the color coordinates of the white light.

In order to obtain the desired color coordinates of the white light, it is possible to adjust the thickness of each of the red, green, and blue color filters. In order to form the desired color filters, the color filters must be newly manufactured. There is a problem that it increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device capable of reducing manufacturing cost and manufacturing time.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a liquid crystal display device comprising: A liquid crystal display device according to an embodiment of the present invention includes a first substrate including a crossing region where a gate line and a data line cross each other and a pixel region defined by the gate line and the data line, And a liquid crystal layer between the first substrate and the second substrate, wherein the transparent metal film is a layer of white light having passed through the second substrate And has a thickness of more than 1000 ANGSTROM to 1700 ANGSTROM or less to adjust the color coordinates.

The details of other embodiments are included in the detailed description and drawings.

The liquid crystal display device according to the present invention uses a transparent metal film having various spectral characteristics according to the thickness, so that the color coordinates of the white light can be adjusted to a desired color coordinate without adjusting the thickness of the color filter, It is possible to reduce the manufacturing cost and the manufacturing period for newly manufacturing the semiconductor device.

1 is a cross-sectional view illustrating a liquid crystal display device according to an embodiment of the present invention.
2 is a cross-sectional view illustrating a liquid crystal display device according to another embodiment of the present invention.
3 is a graph showing a spectrum of a transparent metal film according to the present invention.
4 is a graph showing the color coordinates of blue, green, red, and white according to the present invention.
FIG. 5A is a graph showing the color coordinates of white through adjustment of the thickness of the color filter according to the prior art. FIG.
5B is a graph showing the color coordinates of white through the transparent metal film according to the present invention.

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

1 is a cross-sectional view illustrating a liquid crystal display device according to an embodiment of the present invention.

1, a liquid crystal display device according to an embodiment of the present invention is a liquid crystal display device that realizes a horizontal electric field. The liquid crystal display device includes a lower substrate 250a as a thin film transistor array substrate, The upper substrate 250b as an array substrate is adhered to each other and the liquid crystal layer 230 is formed between the lower substrate 250a and the upper substrate 250b.

A gate line (not shown) and a data line (not shown) crossing each other on the lower substrate 250a, a thin film transistor (TFT) formed in the crossing region, And a pixel electrode 266a and a common electrode 266b formed so as to form a horizontal electric field in a defined pixel area.

The thin film transistor formed at each intersection causes a pixel signal of the data line (not shown) to be charged and held in the pixel electrode 266a in response to a gate signal of a gate line (not shown). The thin film transistor includes a gate electrode 260 connected to a gate line (not shown), a source electrode 263 connected to a data line (not shown), a drain electrode 264 opposed to the source electrode 263 And a semiconductor pattern 262 which overlaps the gate electrode 260 with the gate insulating film 254 interposed therebetween and forms a channel between the source electrode 263 and the drain electrode 264. The source electrode 263, And an ohmic contact layer (not shown) formed on the semiconductor pattern 262 except the channel for ohmic contact with the drain electrode 264.

A protective film 254 having a drain contact hole exposing the drain electrode 264 is formed on the entire upper surface of the thin film transistor. A pixel electrode 266a for forming a horizontal electric field is formed on the passivation layer 254 and a common electrode 267 for forming a horizontal electric field with the pixel electrode 266a is formed under the passivation layer 254. [ Further, the drain electrode 264a and the pixel electrode 266a are connected through the drain contact hole.

The upper substrate 250b includes a black matrix 272 formed to correspond to the boundary of the pixel region formed on the lower substrate 250a and the thin film transistor to prevent light leakage and a red matrix 272 corresponding to the pixel region formed on the lower substrate 250a. A blue color filter, and a green color filter are arranged in this order.

The lower surface of the lower substrate 250a and the upper surface of the upper substrate 250b in contact with the liquid crystal layer 230 include a lower alignment layer 270a and an upper alignment layer 270b on the first surface.

As a result, a horizontal electric field is formed between the pixel electrode 266a to which the pixel signal is supplied through the thin film transistor and the common electrode 267 to which the reference voltage is supplied. The liquid crystal molecules of the liquid crystal layer 230 arranged in the horizontal direction between the pixel electrode 266a and the common electrode 267 are rotated by dielectric anisotropy by the horizontal electric field.

Meanwhile, a transparent metal film 290 is formed on the back surface of the upper substrate 250b of the liquid crystal display device according to an exemplary embodiment of the present invention, that is, the second surface opposite to the first surface.

The transparent metal film 290 may be formed to have a thickness of 200 to 1700 angstroms, and particularly preferably to have a thickness of more than 1000 angstroms and 1700 angstroms or less for adjusting the green or blue coordinates of white light. (Indium Tin Oxide), IZO (Indium Tin Oxide), or the like, and may be selectively formed for adjusting the color coordinates of a desired white light according to the thickness of the transparent metal film 290.

Accordingly, the transparent metal film 290 can adjust the color coordinates of the white light formed through the combination of the red light, the blue light, and the green light having passed through the red color filter, the blue color filter, and the green color filter, respectively, do. In other words, since the transparent metal film 290 has various spectral characteristics depending on the thickness, the color coordinates of the red light, the color coordinates of the blue light, and the color coordinates of the green light can be shifted and adjusted to the desired color coordinates of the white light.

A more detailed description thereof will be described later.

Hereinafter, a liquid crystal display device according to another embodiment of the present invention will be described.

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

2, the liquid crystal display device according to another embodiment of the present invention is a liquid crystal display device implementing a vertical electric field. The liquid crystal display device includes a lower substrate 250a as a thin film transistor array substrate, The upper substrate 250b as an array substrate is adhered to each other and the liquid crystal layer 230 is formed between the lower substrate 250a and the upper substrate 250b.

A gate line (not shown) and a data line (not shown) crossing each other on the lower substrate 250a, a thin film transistor (TFT) arranged in the crossing region, And a pixel electrode 266a formed to form a vertical electric field in a pixel region defined by the pixel electrode 266a.

The thin film transistor formed for each of the intersecting regions includes a gate electrode 260, a source electrode 263 connected to a data line (not shown), a drain electrode 264 opposed to the source electrode 263, a gate insulating film 254 And a semiconductor pattern 262 which overlaps with the gate electrode 260 and forms a channel between the source electrode 263 and the drain electrode 264 with the source electrode 263 and the drain electrode 264 interposed therebetween, And an ohmic contact layer (not shown) formed on the semiconductor pattern 262 except the channel for ohmic contact.

A protective film 254 having a drain contact hole exposing the drain electrode 264 is formed on the entire upper surface of the thin film transistor. A pixel electrode 266a for forming a vertical electric field is formed on the passivation layer 254. Further, the drain electrode 264a and the pixel electrode 266a are connected through the drain contact hole.

The upper substrate 250b includes a black matrix 272 formed to correspond to the boundary of the pixel region formed on the lower substrate 250a and the thin film transistor to prevent light leakage and a red matrix 272 corresponding to the pixel region formed on the lower substrate 250a. A color filter layer 274 having a structure in which blue and green color filters are sequentially arranged and a common electrode 266b that forms a vertical electric field with the pixel electrode 266a of the lower substrate 250b are formed.

The lower surface of the lower substrate 250a and the upper surface of the upper substrate 250b in contact with the liquid crystal layer 230 include a lower alignment layer 270a and an upper alignment layer 270b.

As a result, a vertical electric field is formed between the pixel electrode 266a to which the pixel signal is supplied through the thin film transistor and the common electrode 266b to which the reference voltage is supplied. The liquid crystal molecules of the liquid crystal layer 230 arranged in the vertical direction between the pixel electrode 266a and the common electrode 266b are tilted by the vertical electric field.

Meanwhile, a transparent metal film 290 is formed on the back surface of the upper substrate 250b of the liquid crystal display device according to another embodiment of the present invention, like the transparent metal film 290 formed in the liquid crystal display device according to one embodiment .

The transparent metal film 290 may be formed to have a thickness of 200 to 1700 angstroms, and particularly preferably to have a thickness of more than 1000 angstroms and 1700 angstroms or less for adjusting the green or blue coordinates of white light. (Indium Tin Oxide), IZO (Indium Tin Oxide), or the like, and may be selectively formed for adjusting the color coordinates of a desired white light according to the thickness of the transparent metal film 290.

Accordingly, the transparent metal film 290 can adjust the color coordinates of the white light formed through the combination of the red light, the blue light, and the green light having passed through the red color filter, the blue color filter, and the green color filter, respectively, do. In other words, since the transparent metal film 290 has various spectral characteristics depending on the thickness, the color coordinates of the red light, the color coordinates of the blue light, and the color coordinates of the green light can be shifted and adjusted to the desired color coordinates of the white light.

FIG. 3 is a graph showing the spectrum of the transparent metal film, and FIG. 4 is a graph showing color coordinates of blue, green, red, and white.

In the present invention, when the thickness of the transparent metal film 290 is 200 Å or more to 900 Å or less, the color coordinate of the white light is shifted to the red distribution region. If the thickness is more than 900 Å, more preferably more than 1000 Å to 1300 Å, The color coordinates of the white light are shifted to the green distribution area when the thickness is more than 1300 ANGSTROM to 1700 ANGSTROM or less.

For example, as shown in FIG. 3, the transparent metal film having a thickness of 200 angstroms has a longer wavelength (580 to 660 nm of red wavelength band) than a transmittance of about 89-95% of a shorter wavelength region (380 to 460 nm of blue wavelength band) I.e., 98 to 99%, so that the white coordinates (*) of the color coordinate system shown in FIG. 4 can be shifted to the area where the red color is distributed, so that the color coordinates of the white light can be adjusted.

As shown in FIG. 3, the transparent metal film having a thickness of 1100 angstroms has a transmittance in a range of a short wavelength (380 to 460 nm of blue wavelength band) in comparison with a transmittance of about 89 to 91% in a long wavelength region (580 to 660 nm of red wavelength band) The transmittance, that is, about 94 to 96%, so that the white coordinates (*) of the color coordinate system shown in FIG. 4 can be shifted to the area where the blue color is distributed, so that the color coordinates of the white light can be adjusted.

As shown in FIG. 3, the transparent metal film having a thickness of 1500 angstroms is higher in transmittance in the medium wavelength region (480 to 560 nm in green wavelength band) than in other wavelength band, so that the white coordinate (*) in the color coordinate system shown in FIG. So that the color coordinates of the white light can be adjusted.

If the transparent metal film 290 having various spectral characteristics according to the thickness is used, the color coordinates of the white light can be adjusted to the desired color coordinates without adjusting the thickness of the color filter.

5A and 5B, the range of the color coordinates of the white color of the present invention through the rear transparent metal film is wider than the range of the white color coordinate expression in the conventional art through the thickness adjustment of the color filter.

A liquid crystal display according to an embodiment of the present invention is provided. A liquid crystal display device includes a first substrate including a crossing region where gate lines and data lines intersect and a pixel region defined by the gate lines and the data lines, a first substrate opposing the first substrate, And a liquid crystal layer between the first substrate and the second substrate, and the transparent metal film may have a thickness of more than 1000 ANGSTROM to 1700 ANGSTROM or less to control the color coordinates of white light passing through the second substrate .

The second substrate may include a first surface facing the first substrate and a first surface in contact with the liquid crystal layer and a second surface opposite to the first surface, and a transparent metal film may be disposed on the second surface of the second substrate .

The second substrate further includes a color filter layer disposed on the first side so as to correspond to the pixel region, the red color filter including a green color filter and the blue color filter, and a black matrix disposed between the color filter layers so as to correspond to a crossing region can do.

The transparent metal film may have a thickness of more than 1000 angstroms and less than 1300 angstroms so as to move the color coordinates of the white light passing through the second substrate to the blue distribution region.

The transparent metal film may have a thickness of 1300 ANGSTROM to 1700 ANGSTROM or less so as to move the color coordinate of the white light passing through the second substrate to the green distribution region.

And may further include a pixel electrode and a common electrode arranged in a pixel region of the first substrate.

And a common electrode disposed on a front surface of the second substrate and pixel electrodes arranged in the pixel region of the first substrate.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (7)

A first substrate including a crossing region where gate lines and data lines cross each other and a pixel region defined by the gate lines and the data lines;
A second substrate facing the first substrate and having a transparent metal film disposed at a position corresponding to the pixel region;
A liquid crystal layer between the first substrate and the second substrate; And
And a color filter layer in which a red color filter, a green color filter, and a blue color filter arranged so as to correspond to the pixel region of the first substrate are arranged,
Wherein the transparent metal film has a thickness of more than 1000 ANGSTROM to not more than 1700 ANGSTROM so as to adjust the color coordinates of white light formed through a combination of red light, green light and blue light having passed through the red color filter, the green color filter and the blue color filter,
The color coordinate of the white light passing through the second substrate is adjusted according to the thickness of the transparent metal film,
Wherein the color coordinate of the white light is shifted to a blue distribution region when the transparent metal film has a thickness of more than 1000 ANGSTROM to 1300 ANGSTROM or less and the color coordinate system of the white light is shifted to a green distribution region when the transparent metal film has a thickness of 1300 ANGSTROM to 1700 ANGSTROM or less. Device. The method according to claim 1,
The second substrate includes a first surface facing the first substrate and in contact with the liquid crystal layer, and a second surface opposite to the first surface,
And the transparent metal film is disposed on the second surface of the second substrate. The plasma display panel of claim 2,
And a black matrix disposed between the color filter layers so as to correspond to the intersecting regions. delete delete The method according to claim 1,
Further comprising a pixel electrode and a common electrode arranged in the pixel region of the first substrate. The method according to claim 1,
A pixel electrode arranged in the pixel region of the first substrate,
And a common electrode disposed on a front surface of the second substrate.

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