KR101829848B1 - liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

The present invention provides a liquid crystal display comprising: first and second substrates facing each other and defining a plurality of sub-pixel regions; A plurality of color filters formed on any one of the first substrate and the second substrate and located in the plurality of sub pixel regions, and at least one of the plurality of color filters includes at least one of the plurality of sub pixel regions Pixel area, and has an occupied area in the neighboring sub-pixel area.

Description

[0001] The present invention relates to a liquid crystal display device and a manufacturing method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same.

2. Description of the Related Art [0002] As an information-oriented society develops, demands for a display device for displaying an image have increased in various forms. Recently, a liquid crystal display (LCD), a plasma display panel (PDP) Various flat display devices such as an organic light emitting diode (OLED) display device have been utilized.

Of these, the liquid crystal display device is suitable for being lightweight and thin and widely used.

Hereinafter, a general liquid crystal display device will be described with reference to FIG.

1 is a cross-sectional view schematically showing a liquid crystal panel 1 of a general liquid crystal display device.

1, the liquid crystal panel 1 includes first and second substrates 2 and 3 spaced apart from each other and a liquid crystal layer 4 formed between the first and second substrates 2 and 3 ).

Red, green and blue sub-pixel regions R, G and B are defined on the first substrate 2 and sub-pixel regions R, G and B A thin film transistor T is formed.

Green, and blue color filters RC, GC, BC are formed on the second substrate 3 in correspondence with the red, green, and blue sub-pixel regions R, G,

The black matrix BM is formed on the second substrate 3 in correspondence with the boundaries of the red, green and blue sub-pixel regions R, G and B of the first substrate 2.

That is, in the general liquid crystal panel 1, the color filters RC, GC and BC are formed corresponding to the sub-pixel regions R, G and B, respectively. In other words, the sub-pixel regions R, G, and B and the color filters RC, GC, and BC are formed in a 1: 1 correspondence.

This liquid crystal panel 1 has a problem that it is difficult to implement ITU-R BT.709, which is a chromaticity coordinate standard indicating the color reproduction ratio of HDTV (high definition television).

Generally, a liquid crystal display device processes an image according to an International Telecommunication Union Radiocommunication sector (ITU-R) Broadcasting Service Television (BT). However, until now, images have generally been transmitted in the national television standards committee (NTSC), and the color reproduction rate of this NTSC system is different from the color reproduction rate of ITU-R BT.709 as shown in Table 1 .

[Table 1] shows the chromaticity values of NTSC and ITU-R BT.709, which are based on the coordinate system values specified by the International Commission on Illumination (CIE) in 1931

Referring to FIG. 2 and Table 2, the color reproduction ratio of a general liquid crystal panel will be described.

2 is a simulation result showing the intensity of light with respect to the wavelengths of red light, green light and blue light and the light transmittance by a color filter in a red, green, and blue sub-pixel regions of a general liquid crystal panel. The transmittance of light by the color filter in the red, green, and blue sub-pixel areas of the paddle was determined as the value of the color coordinate value of the ITU-R BT.709, which was set in 1931 by the International Commission on Illumination (CIE) It is by coordinate system value

First, as shown in FIG. 2, the blue light has a light intensity corresponding to about 0.8 at about 430 nm, the green light has a light intensity corresponding to about 0.8 at about 530 nm, the red light has an intensity corresponding to about 0.8 at about 630 nm And has a light intensity corresponding to about one.

The color coordinate values of the red, green, and blue sub-pixel regions (R, G, and B in FIG. 1) are as shown in [Table 2]. These values have values significantly different from those in [Table 1].

Therefore, in the case of a general liquid crystal panel, additional algorithms and circuits are required to process and convert images so that an image having an NTSC color coordinate value can express a color coordinate value of ITU-R BT.709, There is a problem in that it increases.

In other words, a general liquid crystal panel does not realize the color reproduction rate of ITU-R BT.709, and additional algorithms are required to realize the color reproduction ratio according to ITU-R BT.709, and a complicated circuit Design and the like.

According to the present invention, a color filter corresponding to each sub-pixel area is extended to a neighboring sub-pixel area without a separate algorithm and a driving circuit, and a liquid crystal display capable of satisfying a color reproduction rate according to ITU-R BT.709 And a method of manufacturing the same.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: first and second substrates opposing each other and defining a plurality of sub-pixel regions; A plurality of color filters formed on any one of the first substrate and the second substrate and located in the plurality of sub pixel regions, and at least one of the plurality of color filters includes at least one of the plurality of sub pixel regions Pixel area, and has an occupied area in the neighboring sub-pixel area.

And a black matrix is formed on the second substrate corresponding to the boundary portions of the plurality of color filters.

The occupied area is configured such that the neighboring sub-pixel area has a color reproduction rate of ITU-R BT.709.

More specifically, the plurality of sub-pixel regions include first through third sub-pixel regions sequentially arranged, the second sub-pixel region includes a first region adjacent to the first sub-pixel region, Pixel region and a second region neighboring the third sub-pixel region, wherein the third sub-pixel region includes a third region adjacent to the second sub-pixel region, and wherein the first sub-pixel region A second color filter located in the second sub-pixel region of the plurality of color filters is formed in the second region and the second region in the second sub- And the second region is formed corresponding to the third region.

The first region is 15 to 20% of the area of the second sub-pixel region.

The third region is 3 to 8% of the area of the third sub-pixel region.

Each of the first through third sub-pixel regions is a red sub-pixel region, a green sub-pixel region, and a blue sub-pixel region.

A first substrate and a second substrate facing each other and defining a plurality of sub-pixel regions, and a plurality of color filters formed in any one of the first substrate and the second substrate and located in the plurality of sub-pixel regions Wherein at least one of the plurality of color filters extends to an adjacent sub-pixel region among the plurality of sub-pixel regions and has an occupied area in the neighboring sub-pixel region, Forming a black matrix on the second substrate, the black matrix having openings corresponding to the plurality of color filter boundaries; And forming the plurality of color filters on the opening and on the black matrix.

The liquid crystal display device according to the present invention can satisfy the color coordinate values of the ITU-R BT.709 by providing the color filters corresponding to the respective sub-pixel regions to the neighboring sub-pixel regions, thereby providing improved image quality do.

In addition, since a separate algorithm for satisfying the color coordinate values of ITU-R BT.709 and a driving circuit for driving the same are not needed, the manufacturing cost is reduced.

1 is a cross-sectional view schematically showing a liquid crystal panel of a general liquid crystal display device.
2 is a simulation result showing the intensity of light with respect to the wavelengths of red light, green light, and blue light, and the transmittance of light by the color filter in the red, green, and blue sub-pixel regions of a general liquid crystal panel.
3 is a schematic exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.
4 is a cross-sectional view schematically showing a part of a liquid crystal display device according to an embodiment of the present invention.
5 is a plan view schematically showing a liquid crystal panel of FIG. 4 viewed from the front;
6 is a simulation result showing the intensity of the light with respect to the wavelength and the transmittance of the color filter with respect to the wavelength of the liquid crystal panel according to the embodiment of the present invention.
7 is a graph comparing the light transmittance by a color filter in a green subpixel region and the transmittance of light by a color filter in a green subpixel region according to an embodiment of the present invention.
8 is a graph comparing light transmittance by a color filter in a blue sub-pixel region of a general liquid crystal panel and light transmittance by a color filter in a blue sub-pixel region according to an embodiment of the present invention.
9A to 9D are schematic views showing a manufacturing process sequence of a color filter according to an embodiment of the present invention.
10 is a cross-sectional view schematically showing a liquid crystal panel according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

3 is a schematic exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.

3, the liquid crystal display device 10 includes a liquid crystal panel 20 for displaying an image, a first polarizing film 50 and a second polarizing film 50 respectively formed on the upper and lower portions of the liquid crystal panel 20, A film 52, and a backlight 80 positioned on the back surface of the liquid crystal panel 20. [

The liquid crystal panel 20 includes a first substrate 21 and a second substrate 22 facing each other, and a liquid crystal layer (not shown) interposed therebetween.

Here, on the first substrate 21, for example, red, green, and blue sub pixel regions (R, G, B) arranged in the horizontal direction (x axis direction) Green, and blue color filters (RC, GC, BC) are formed on the second substrate 22 corresponding to the red, green, and blue sub-pixel regions R, G, The liquid crystal panel 20 will be described in more detail with reference to FIG.

 The first and second polarizing films 50 and 52 transmit only linearly polarized light parallel to the light transmission axis and the light transmission axis of the first polarizing film 50 and the light transmission axis of the second polarizing film 52 are perpendicular to each other .

On the other hand, the backlight 80 is positioned on the back surface of the liquid crystal panel 20 and serves to supply light to the liquid crystal panel 20. [ A cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED) are used as the light source of the backlight 80. In particular, LEDs are widely used as light sources for displays, having characteristics such as small size, low power consumption, and high reliability.

Hereinafter, the liquid crystal panel 20 according to the embodiment of the present invention will be described in more detail with reference to FIG.

4 is a cross-sectional view schematically showing a part of a liquid crystal display device 10 according to an embodiment of the present invention and includes a liquid crystal panel 20 and a backlight 80 positioned on the backside of the liquid crystal panel 20 and supplying light, Fig.

4, the liquid crystal panel 20 includes first and second substrates 21 and 22 spaced apart from each other and a liquid crystal layer (not shown) formed between the first and second substrates 21 and 22 48).

On the first substrate 21, gate wirings (not shown) and data wirings (not shown) are formed to intersect with each other to define the sub-pixel regions SP. The red, green, and blue subpixel regions R, G, and B may include red, green, and blue subpixel regions R, G, and B, For example, in the horizontal direction (x-axis direction).

At this time, a thin film transistor T composed of a gate electrode 24, a semiconductor layer 28, a source electrode 32 and a drain electrode 34 is formed in each of the red, green and blue sub-pixel regions R, G and B, .

Specifically, a gate electrode 24 connected to the gate wiring is formed on the first substrate 21, and a gate insulating layer 26 is formed on the gate wiring and the gate electrode 24.

A semiconductor layer 28 is formed on the gate insulating layer 26 corresponding to the gate electrode 24 and a source electrode 32 and a drain electrode 34 are formed on the semiconductor layer 28. At this time, the source electrode 32 is connected to the data line.

A protective layer 36 is formed on the source electrode 32, the drain electrode 34 and the data line. The protective layer 36 includes a drain contact hole 36a exposing the drain electrode 34 .

The pixel electrode 38 connected to the drain electrode 34 through the drain contact hole 36a is formed on each of the red, green and blue sub-pixel regions R, G and B on the protection layer 36.

The portion of the first substrate 21 where the thin film transistor T is formed is a non-display region NDA in which light supplied from the backlight 80 is blocked by the thin film transistor T, And the other part becomes a display area DA in which an image is substantially displayed.

At the bottom of the second substrate 22, a black matrix 42 and a color filter 44 are formed.

First, the color filter 44 may include red, green, and blue color filters (RC, GC, BC) corresponding to red, green, and blue sub pixel regions (R, G, B), for example.

Also, at least one of the red, green, and blue color filters (RC, GC, BC) may be formed extending to the neighboring sub-pixel region (SP). At this time, the neighboring sub-pixel areas SP may be at least one of left and right.

At this time, when at least one of the red, green, and blue color filters (RC, GC, BC) extends to the neighboring sub pixel areas SP, the color filter 44 occupies the neighboring sub pixel areas SP The area can be designed variously according to the color reproduction rate to be implemented.

For example, the area occupied by the color filter 44 corresponding to the other pixel area SP in the neighboring sub-pixel area SP is the ITU-T, which is the chromaticity coordinate standard indicating the color reproduction ratio of HDTV (high definition television) R BT.709. ≪ / RTI >

Generally, the liquid crystal display 10 processes an image according to ITU-R (International Telecommunication Union Radiocommunication sector) BT (Broadcasting Service Television) However, until now, images have generally been transmitted in the national television standards committee (NTSC), and the color reproduction rate of the NTSC system is different from the color reproduction rate of ITU-R BT.709. Accordingly, the color filter 44 corresponding to the other pixel region SP is extended to the neighboring sub-pixel region SP so that the image having the NTSC color coordinate value can be expressed by the color coordinate value of the ITU-R BT.709. . This is because, when each sub-pixel area SP is driven, the color reproduction by the color filter 44 corresponding thereto and the color reproduction by the color filter 44 further extended are combined. 709 can be satisfied.

The black matrix 42 is formed at the boundary of the color filter 44. Specifically, for example, the black matrix 42 is formed by combining the boundary between the red color filter RC and the green color filter GC, the boundary between the green color filter GC and the blue color filter BC, BC) and the red color filter (RC).

At this time, the black matrix 42 may be symmetrical with respect to the center of the boundary of the color filter 44, for example.

In other words, the black matrix 42 is formed corresponding to the boundary of the color filter 44, corresponding to the extended color filter 44, not formed corresponding to the boundary of the sub pixel area SP.

Meanwhile, when the vertical electric field liquid crystal layer 48 is driven, a transparent common electrode 46 may further be formed under the color filter 44.

Although the pixel electrode 38 and the common electrode 48 are formed on the first and second substrates 21 and 22, respectively, the pixel electrode and the common electrode may be formed on the first substrate 21 .

In yet another embodiment, the black matrix may be formed at the boundary of the sub-pixel region. In other words, a black matrix having openings corresponding to the sub-pixel regions and corresponding to the thin film transistors, the data lines and the gate lines can be formed on the second substrate.

Hereinafter, a more specific example will be given with reference to FIG.

5 is a plan view schematically showing the liquid crystal panel 20 of FIG. 4 viewed from the front.

First, the red, green, and blue sub-pixel regions R, G, and B are arranged in the x-axis direction and the red, green, and blue sub- Red, green, and blue color filters (RC, GC, BC) are arranged in the x-axis direction at the top.

At this time, the red color filter RC is formed extending not only to the red sub-pixel region R but also to the green sub-pixel region G.

Here, the first occupied area SA1 occupied by the red color filter RC in the green sub-pixel area G is about 15% of the display area of the green sub-pixel area G (DA in Fig. 4) To 20%. At this time, the first width w1 represents the section length in the x-axis direction when the red color filter RC occupies about 16 to 17% of the green sub-pixel area G.

Further, the green color filter GC is formed extending not only to the upper portion of the green sub-pixel region G but also to the blue sub-pixel region B.

Here, the second occupied area SA2 occupied by the green color filter GC in the blue sub-pixel region B is, for example, approximately equal to that of the display region (DA in Fig. 4) of the blue sub- 3 to 8%. At this time, the second width w2 represents the cross-sectional length in the x-axis direction when the green color filter GC occupies about 5% of the blue sub-pixel region (B).

At this time, the first occupied area SA1 and the second occupied area SA2 may be variously designed to implement the chromaticity coordinates of ITU-R BT.709 as described above.

On the other hand, a black matrix 42 is formed at the boundary of each color filter 44.

Hereinafter, the intensity of light with respect to the wavelength of the liquid crystal panel 20 and the light transmittance by the color filter according to the embodiment of the present invention will be described with reference to FIGS.

 6 is a simulation result showing the intensity of light with respect to a wavelength and the transmittance of a color filter with respect to a wavelength of a liquid crystal panel according to an embodiment of the present invention. 2) of the conventional liquid crystal panel (see FIG. 1) and the transmittance of light by the color filter of the green sub-pixel region according to the embodiment of the present invention. FIG. (See FIG. 2) and the light transmittance by the color filter of the blue sub-pixel region according to the embodiment of the present invention.

Here, the horizontal axis represents the wavelength region of light, and the vertical axis represents the intensity of light and the transmittance of light by the color filter.

6, the blue light has a light intensity corresponding to about 0.8 at about 430 nm, the green light has a light intensity corresponding to about 0.8 at about 530 nm, the red light has a light intensity corresponding to about 0.8 at about 630 nm, And the light intensity corresponding to the light intensity.

Here, with reference to [Table 3], the transmittance of light by the color filter of each sub-pixel region is examined.

Table 3 shows the color filter (CF in Fig. 4) of the red, green and blue sub-pixel regions (R, G and B in Fig. 4) of the liquid crystal panel (20 in Fig. 4) The transmittance of light is the value of the color coordinate value of ITU-R BT.709, which is based on the coordinate system value specified by the International Commission on Illumination (CIE) in 1931.

Referring to the red subpixel region (R in FIG. 4), the color coordinate value of the x-axis of the light transmittance by the color filter is 0.644 and the color coordinate value of the y-axis is 0.321. (See Table 2) of the pixel region and is similar to the color coordinate value of ITU-R BT.709 (see Table 1).

4), the color coordinate value of the x-axis of light transmittance by the color filter, that is, the green color filter (GC in Fig. 4) and the red color filter (RC in Fig. 4) is 0.303, The color coordinate value of the y axis is 0.615, which is similar to 0.3 (x axis) and 0.6 (y axis), which are values in the green subpixel area of ITU-R BT.709 (see Table 1).

7 will be described together. In FIG. 7, the comparative example (Ref) shows the transmittance of light by the color filter in the green subpixel region in the general liquid crystal panel, and the embodiment shows the light transmittance by the color filter in the green subpixel region according to the embodiment of the present invention Transmittance.

The green subpixel region (G in FIG. 4) according to the embodiment of the present invention is a region in which the light is transmitted by the red color filter (RC in FIG. 4) as well as the green color filter (GC in FIG. 4) At above 580 nm, the transmittance of light is higher than that of a green subpixel region of a general liquid crystal panel.

Accordingly, as the color reproduction ratio of the green subpixel region (G in Fig. 4) is improved, the green subpixel region (G in Fig. 4) according to the embodiment of the present invention has a color more suitable for ITU-R BT.709 .

4B), the x-axis color coordinate value of the light transmittance by the color filter, that is, the blue color filter (BC in Fig. 4) and the green color filter (GC in Fig. 4) is 0.155, The y-axis color coordinate value is 0.058, which is similar to 0.155 (x-axis) and 0.58 (y-axis) values in the green subpixel region of ITU-R BT.709 (see Table 1).

8 will be described together. In FIG. 8, the comparative example (Ref) shows the transmittance of light by the color filter in the blue sub-pixel region in the general liquid crystal panel, and the embodiment shows the light transmittance by the color filter in the blue sub- Transmittance.

The blue subpixel region (B in FIG. 4) according to the embodiment of the present invention transmits light not only by the blue color filter (BC in FIG. 4) but also by the green color filter (GC in FIG. 4) At a wavelength higher than 480 nm, the transmittance of light is higher than that of a blue sub pixel region of a general liquid crystal panel.

Accordingly, the blue sub-pixel region (B in FIG. 4) according to the embodiment of the present invention has a color more suitable for ITU-R BT.709 as the color reproduction rate of the blue sub-pixel region .

As described above, in the embodiment of the present invention, at least one or more color filters among the color filters corresponding to each of the sub-pixel regions are extended to the neighboring sub-pixel regions, thereby achieving color reproduction more suitable for ITU-R BT.709 have.

Hereinafter, a method of manufacturing a color filter according to an embodiment of the present invention will be described with reference to FIGS. 9A to 9D.

9A to 9D are schematic views showing a manufacturing process sequence of a color filter according to an embodiment of the present invention.

First, as shown in FIG. 9A, a metal material or a black resin material is deposited on the entire surface of the transparent second substrate 22, and then the first to the And a black matrix 42 having three openings op1, op2 and op3 is formed.

At this time, the black matraxes 42 are formed corresponding to the boundaries of red, green, and blue color filters (RC, GC, and BC in FIG. 4, respectively).

Next, as shown in FIG. 9B, any one of red, green, and blue is formed on the second substrate 22 on which the black matrix 42 having the first to third openings op1, op2, and op3 is formed A red color pigment is coated on the entire surface by a method such as spin coating or bar coating to form a red color filter layer RCL.

After a red color filter layer RCL is formed on the second substrate 22, a mask (not shown) having a transmissive region for passing light and a blocking region for blocking light is formed on the second substrate 22 And then the red color filter layer (RCL) is exposed and developed to form a red color filter (RC) repeatedly spaced apart at a predetermined interval as shown in FIG. 4C.

At this time, the red color filter RC may be formed in the first opening (op1) region, for example.

4D, the green color filter GC and the blue color filter BC are formed on the black matrix 42 (FIG. 4D) on the second substrate 22, The second and third openings op2 and op3.

Accordingly, red, green, and blue color filters (RC, GC, and BC) are formed on the second substrate 22 in this order.

As described above, in the embodiment of the present invention, the color filter formed on the second substrate is formed not only in the corresponding sub-pixel region of the first substrate but also in the neighboring sub-pixel region, thereby forming a liquid crystal panel having excellent color reproduction rate.

Meanwhile, another embodiment will be described with reference to FIG.

10 is a cross-sectional view schematically illustrating a liquid crystal panel according to another embodiment of the present invention. A color filter CF1 including, for example, red, green and blue color filters RC1, GC1 and BC1 may be formed on the first substrate 21, At least one of the red, green, and blue color filters RC1, GC1, and BC1 may extend to neighboring sub-pixel regions in order to realize a color reproduction ratio suitable for R BT709.

In addition, although the color reproduction ratio of ITU-R BT.709 has been described in the embodiment of the present invention, the present invention is not limited thereto and can be applied to various color coordinates indicating the color reproduction ratio. For example, it is applicable to ITU-R BT.706, PAL, etc. of s-RGB.

The present invention is not limited to the above-described embodiments, and various changes and modifications may be made without departing from the spirit of the present invention.

21: first substrate 22: second substrate 44: color filter
RC: Red color filter GC: Green color filter BC: Blue color filter
R: red sub pixel area G: green sub pixel area B: blue sub pixel area

Claims (10)

A first substrate and a second substrate facing each other and defining a plurality of sub-pixel regions;
A plurality of color filters formed on any one of the first substrate and the second substrate and located in the plurality of sub-pixel regions,
Wherein at least one of the plurality of color filters extends to neighboring subpixel regions of the plurality of subpixel regions and has an occupied area in the neighboring subpixel regions.
The method according to claim 1,
And a black matrix corresponding to the plurality of color filter boundary portions is formed on the second substrate.
The method according to claim 1,
Wherein the occupancy area is such that the neighboring sub-pixel region has a color reproduction rate of ITU-R BT.709. The method according to claim 1,
Wherein the plurality of sub-pixel regions include first through third sub-pixel regions sequentially arranged,
Wherein the second sub-pixel region comprises a first region neighboring the first sub-pixel region and a second region adjacent to the third sub-pixel region,
Wherein the third sub-pixel region includes a third region adjacent to the second sub-pixel region,
Wherein a first color filter located in the first sub-pixel region among the plurality of color filters is formed corresponding to the first sub-pixel region and the first region,
And a second color filter located in the second sub-pixel region among the plurality of color filters is formed corresponding to the second region and the third region.
5. The method of claim 4,
Wherein the first region is 15 to 20% of the area of the second sub-pixel region.
5. The method of claim 4,
And the third region is 3 to 8% of the area of the third sub-pixel region.
5. The method of claim 4,
Wherein each of the first through third sub-pixel regions is a red sub-pixel region, a green sub-pixel region, and a blue sub-pixel region.
A first substrate and a second substrate facing each other and defining a plurality of sub-pixel regions, and a plurality of color filters formed in any one of the first substrate and the second substrate and located in the plurality of sub-pixel regions Wherein at least one of the plurality of color filters extends to an adjacent sub-pixel region among the plurality of sub-pixel regions and has an occupied area in the neighboring sub-pixel region,
Forming a black matrix on the second substrate having openings corresponding to the plurality of color filter boundaries;
Forming the plurality of color filters on the opening and on the black matrix
And a liquid crystal layer.
9. The method of claim 8,
Wherein the neighboring sub-pixel regions are light-transmissive by color filters located in the at least one of the plurality of color filters and the neighboring sub-pixel regions.
The method according to claim 1,
Wherein the neighboring sub-pixel regions transmit light by a color filter located in the at least one of the plurality of color filters and the neighboring sub-pixel regions.

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