KR100557734B1 - Reflective liquid crystal display device having a new reflective color filter - Google Patents

Abstract

The present invention relates to a reflective liquid crystal display device, and more particularly, to a reflective color liquid crystal display device having a reflective color filter having a novel structure.

Reflective color filter according to the present invention is a red / green / blue / white area by adding a white area that does not absorb light to the existing red / green / blue structure in various arrangements easier than conventional transmittance of the color filter And color purity can be adjusted.

Reflective Color Filter, Reflective Color Liquid Crystal Display

Description

Reflective liquid crystal display device having a new reflective color filter}             

1 is a cross-sectional view showing a general color liquid crystal panel,

2 is a cross-sectional view showing the structure of a color filter constituting a unit pixel,

3A to 3C are plan views showing the arrangement of the color filters;

4 is a perspective view illustrating a color filter structure according to a first embodiment of the present invention;

5 is a perspective view illustrating a color filter structure according to a second embodiment of the present invention;

6 is a perspective view illustrating a color filter structure according to a third embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

73: red color filter 75: green color filter

77: blue color filter 79: white subpixel

The present invention relates to a reflective liquid crystal display device, and more particularly, to a reflective color liquid crystal display device having a new color filter.

The reflective color liquid crystal display is a method for manufacturing a low power consumption and low capacity portable terminal. Instead of using artificial internal light of a backlight to implement an image, it transmits external light to a liquid crystal panel and by a predetermined reflecting means. A method of realizing an image by reflecting in a display mode.

FIG. 1 is a schematic view illustrating a general color liquid crystal panel, and briefly includes a first polarizer 11, a lower transparent substrate 13, a liquid crystal driving device 15, a pixel electrode 17, and a lower alignment layer 19. And a liquid crystal layer 21, an upper alignment layer 22, an upper common electrode 23, a color filter layer 25, an upper transparent substrate 27, and a second polarizing plate 29.

In the case of a reflective liquid crystal panel, a reflective plate using a metal instead of the lower polarizer or a pixel electrode is formed of metal to perform a reflective function.

Among the components of the color liquid crystal panel, the color filter 25 is an important factor that determines the clear image quality of the liquid crystal display, and a general structure thereof is shown in FIG. 2.

In detail, the color filter 25 structure includes a substrate 31, a color resin layer 33, a black matrix 35, and a transparent common electrode 37. The substrate 31 generally includes a glass substrate. The color filter film is formed by arranging red, green, and blue three-color resins (resins) on the glass substrate in correspondence with each pixel. In this case, the black matrix 35 is formed using chromium (Cr), chromium oxide (CrO _X ), an organic material, etc. to block leakage light and improve contrast ratio between each color resin layer. .

In the reflective liquid crystal display, the black matrix may not be used to increase light transmittance and reflectance.

The transparent electrode 37 is positioned on the black matrix 35 formed between the color resin layers 33 and the color resin layers.

The transparent electrode 37 is formed on the color filter film 25 or on an overcoat (not shown) by using a method such as a sputter, which is excellent in transmittance, resistance, and ease of processing. It will act to drive the liquid crystal.

In general, the color filter color array may be configured differently, and the basic structure and arrangement of the color filter may include a stripe array 41, a mosaic array 51, and a delta as shown in FIGS. 3A to 3C. (delta) array 61, and so on.

In general, the color filter should be high in color density, good light transmittance, no discoloration or discoloration by external light or backlight, no peeling, discoloration and discoloration for electrode process, chemically stable and harmless to liquid crystal material. .

The biggest concern of the color liquid crystal display device having such a color filter is how clearly the color purity and the color contrast are expressed.

Furthermore, in a reflective liquid crystal display device that implements an image depending on external light without using a backlight, expressing various color purity and color contrast by light is of great interest.

The color filter of the reflective liquid crystal display device generally uses a method of adjusting the average transmittance to 55 to 70% by varying the thickness of each color layer and the concentration of the pigment.

However, even with a high transmittance such that the average transmittance is 55 to 70% using the above-described method, it is difficult to realize a clear image due to the low reflectance of the reflective liquid crystal display device in indoor or cloudy weather when the illumination of external light is insufficient. .

Moreover, even if the illuminance of the external light is high and the reflectance is sufficient, the color purity expressed by the red / green / blue color filter is fixed.

That is, the existing structure has a problem that the transmittance and color purity of the color filter are fixed irrespective of the illuminance of the external light, and it is pointed out as a process problem when controlling the transmittance and color purity by adjusting the thickness of each color resin layer.

Accordingly, the present invention has been made to solve this problem, and provides a color filter for a reflective liquid crystal display device having a new structure, and applying the new color filter to provide a reflective liquid crystal display device having higher reflectance and excellent color purity. The purpose is to provide.

In order to achieve the above object, the present invention configures the reflective color filter by adding a transparent area that does not absorb light to the existing color filter structure.

According to an aspect of the present invention, a color filter for a reflective liquid crystal display device includes: a glass substrate; Red subpixels, green subpixels, blue subpixels, and transparent subpixels arranged on the glass substrate and forming unit pixels; Provided is a color filter for a reflective liquid crystal display device including a transparent electrode deposited on a front surface of a substrate including each of the red, green, blue, and transparent subpixels.
Preferably, the arrangement of the red, green, blue, and transparent subpixels is one of strip, square, and mosaic arrangements.
According to another aspect of the present invention, a color filter for a reflective liquid crystal display device includes: a glass substrate; a red subpixel, a green subpixel, a blue subpixel, and a portion of each of the red, green, and blue subpixels arranged on the glass substrate. A transparent subpixel formed in the subpixel to form a single pixel together with each of the subpixels; Provided is a color filter for a reflective liquid crystal display device including a transparent electrode deposited on a front surface of a substrate including each of red, green, and blue subpixels.
The subpixels may be arranged in one of strip, square, and mosaic arrangements, and the transparent subpixels may be formed to have a predetermined length with the same width as the red, green, and blue subpixels.
According to another aspect of the present invention, a color filter for a reflective liquid crystal display device includes a glass substrate; a red subpixel, a green subpixel, a blue subpixel, and the red, green, blue subpixel, and a single pixel arranged on the glass substrate. A transparent subpixel formed around the subpixel; Provided is a color filter for a reflective liquid crystal display device including a transparent electrode deposited on a front surface of a substrate including the red, green, blue subpixels, and a transparent subpixel.
Preferably, the arrangement of each of the red, green, and blue subpixels is one of a strip, delta, and mosaic arrangement.
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

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First Embodiment

The color filter of the reflective color liquid crystal display device according to the present invention is configured by further adding a white subpixel, that is, a transparent subpixel, to an existing three-color subpixel of red / green / blue type.

FIG. 4 illustrates a color filter for a reflective liquid crystal display device according to a first embodiment of the present invention, wherein a red 73, green 75, blue 77, and white subpixel region 79 are disposed on a substrate 71. ) Is arranged in a stripe form to form one unit pixel.

This structure can be applied not only to the stripe arrangement but also to the mosaic arrangement or the square arrangement.

The white subpixel 79 may or may not coat the transparent resin layer.

When the white subpixel 79 is added to form a color filter and the white subpixel is driven in a place where the external light is low in illumination, the amount of light reflected by the reflecting means is further increased by the white subpixel. This reflection allows the reflectance to be improved, thereby enabling the use of a reflective liquid crystal display device having improved overall brightness even in a dark place.

When the white subpixel is in a black state in a place where the external light is high, the brightness may be good and the color purity may be further improved.

Accordingly, when the ratio of the white subpixels to the brightness may be adjusted according to the illuminance of the external light, a liquid crystal display device having optimal brightness and color purity may be realized according to the location.

Second Embodiment

In the second embodiment according to the present invention, a color region and a white region are configured together in one subpixel.

FIG. 5 illustrates a configuration of a color filter according to a second exemplary embodiment of the present invention, wherein red (83), green (85), and blue (87) are disposed on the substrate (81) corresponding to each subpixel (80). Each color area of the?) Is disposed, and a part of each subpixel 80 is formed of the white area 89 by a predetermined length with the same width as each subpixel to form a color filter.

That is, each color area 83, 85, 87 and white area 89 are configured together in one subpixel.

In addition, each color subpixel configured as described above may be formed of a strip array, a mosaic array, a delta array, and the like to form a color filter film, and the white region may or may not be coated with a transparent resin.

When the above-described configuration is used, the white region can be configured without adding a sub-pixel for the white region as in the first embodiment, and the color is set so that the transmittance is 55 to 70% as in the conventional reflective color filter. There is no need to adjust the thickness of the resin layer or the concentration of the pigment.

That is, it is possible to freely adjust the transmittance by determining only the area ratio in which the color resin layer is formed in each subpixel.

Third embodiment

FIG. 6 illustrates a configuration of a color filter according to a third embodiment of the present invention, and includes a red 93, a green 95, and a blue 97 at a portion of each subpixel, for example, at the center of each subpixel. The structure of forming the color resin layer and forming the circumference of the color subpixel in which the color resin layer is not formed as the white region 99 is shown.

Such a structure may be described as if each color resin layer is coated on the white area at regular intervals.

Such a configuration allows for easier control of the transmittance than the case of adjusting the thickness or pigment concentration while forming the color resin layer, and further improves color purity by preventing color mixing.

In addition, each color subpixel configured as described above may be formed of a strip array, a mosaic array, a delta array, or the like to form a color filter film.

When the color resin layer is formed on a part of the pixel to adjust the light transmittance like the color filter of the new configuration according to the present invention as described above, the transmittance of the corresponding wavelength range expressing the color is also increased to improve the color purity relatively. .

Furthermore, in the third embodiment, when the color resin layer is formed in several regions within one pixel and the structure is surrounded by transparent regions, a diffusion effect is generated due to the difference in refractive index between the region where the color resin layer is formed and the region where the color resin layer is not formed. Contributes to improving the reflectance of light.

In the above-described color filter for the reflective liquid crystal display device, color resin layers such as yellow, cyano, and magenta may be used instead of red, green, and blue.

The new color filter may be applied regardless of the liquid crystal mode or the light scattering method.

As described above, the reflective color liquid crystal display device according to the present invention has the following effects by adding a white region to the existing color filter structure.

First, it is possible to implement a reflective display device having an optimal reflectance and color purity according to the illuminance of external light. Second, the transmittance and color purity of each color filter can be adjusted more easily than the conventional color filter film. Incidentally, the reflectance of the display device is increased due to the light diffusion effect.

Claims (7)

Glass substrates; Red subpixels, green subpixels, blue subpixels, and transparent subpixels arranged on the glass substrate and forming unit pixels; Transparent electrodes deposited on the front surface of the substrate including each of the red, green, blue, and transparent subpixels Color filter for a reflective liquid crystal display device comprising a. The method of claim 1, Wherein the array of red, green, blue, and transparent subpixels is one of a strip, square, and mosaic arrangement. Glass substrates; Red sub pixels, green sub pixels, blue sub pixels arranged on the glass substrate, A transparent subpixel formed on a part of each of the red, green, and blue subpixels and forming a single pixel together with the subpixels; Transparent electrodes deposited on the front of the substrate including each of the red, green, and blue subpixels Color filter for a reflective liquid crystal display device comprising a. The method of claim 3, wherein Wherein each subpixel array is one of a strip, a square, and a mosaic array. The method of claim 3, wherein And the transparent subpixels are formed to have the same width as the red, green, and blue subpixels by a predetermined length. Glass substrates; Red sub pixels, green sub pixels, blue sub pixels arranged on the glass substrate, A transparent subpixel that forms a single pixel with the red, green, and blue subpixels and is formed around each subpixel; Transparent electrodes deposited on the front surface of the substrate including the red, green, blue subpixels, and transparent subpixels Color filter for a reflective liquid crystal display device comprising a. The method of claim 6, Wherein each of the red, green, and blue subpixel arrays is one of a strip, delta, and mosaic array.

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