CN1266525C - Black matrix, color optical filter and liquid crystal display device - Google Patents

Abstract

The present invention relates to a black matrix, and a color filter and a liquid crystal display using the black matrix. The black matrix comprises a first reflection resisting layer, a shading layer and a second reflection resisting layer. The first reflection resisting layer, the shading layer and the second reflection resisting layer are sequentially arranged. The second reflection resisting layer comprises at least one chromic oxide or chromic nitride thin film.

Description

Black matrix, color filter and liquid crystal display device

【Technical field】

The invention relates to a black matrix, a color filter using the black matrix and a liquid crystal display device.

【Background technique】

Liquid crystal display is a passive display device. In order to achieve the effect of color display, a color filter needs to be provided for it. Its function is to provide color for the liquid crystal display. components to display different color images.

Please refer to FIG. 1 , which is a schematic structural diagram of a color filter in the prior art. The color filter 20 includes a glass substrate 24 , a black matrix 23 , a colored layer 22 and an ITO (Indium Tin Oxide, indium tin oxide) layer 21 . The colored layer 22 has three colored units of red (R), blue (B), and green (G), and the three colored units are repeatedly and regularly arranged on the glass substrate 24 to pass through the three primary colors of red, blue, and green light respectively, and block Light of other wavelengths passes through. The black matrix 23 is arranged between the three coloring units, and its function is to block the light passing through the three coloring units, prevent light from leaking and prevent coloring materials from mixing, and the ITO layer 21 cooperates with a TFT array (not shown), The amount of light passing through each coloring unit of the coloring layer 22 is controlled to display different colors.

The black matrix 23 is generally composed of chromium and its compounds or black resin, and its optical properties depend on its OD (Optical Density, optical density) and reflectivity. OD indicates the light-shielding ability of the black matrix, and the reflectance refers to the light reflectance on both sides of the black matrix. When the black matrix is applied to a liquid crystal display, the surface of the black matrix adjacent to one side of the liquid crystal display and the other surface opposite to it will be respectively irradiated by external light and the backlight of the liquid crystal display. If the reflectivity is too high, the reflected light will be excessive. Too many light interference problems.

The higher the OD value and the lower the reflectivity of the black matrix, when it is applied to a liquid crystal display, it can make the liquid crystal display have high display contrast and clear images, otherwise, the display effect will be poor. The black matrix composed of black resin material has low reflectivity, but its OD value is not high, and the black matrix composed of chromium and its compounds has high OD value, but its reflectivity is too high.

A color filter using a black matrix composed of chromium and its compounds is disclosed in US Patent No. 6,285,424 published on September 4, 2001. Please refer to FIG. 2 , the color filter 1 includes a transparent glass substrate 2 , a black matrix 9 , a protection layer 6 and a transparent electrode layer 7 , and a polarizer 8 is arranged on the surface of the color filter 1 . The black matrix 9 includes a first anti-reflection film 3 , a second anti-reflection film 4 and a light-shielding layer 5 sequentially disposed on the transparent glass substrate 2 .

The first anti-reflection film 3 and the second anti-reflection film 4 include different metal compounds. The light-shielding layer 5 is composed of chromium, molybdenum, tungsten, nickel or germanium, which is different from the metal used in the first anti-reflection film 3 and the second anti-reflection film 4, the first anti-reflection film 3 and the second anti-reflection film The thickness of the reflective film 4 is preferably 20 to 60 nm, and the thickness of the light shielding layer 5 is preferably 50 to 150 nm.

This patented technology uses the principle of interference and destructive interference of reflected light on the surfaces of the first anti-reflection film 3, the second anti-reflection film 4, and the light-shielding layer 5 to reduce the reflectivity, which can effectively reduce the reflectivity entering from the side of the liquid crystal display and passing through the transparent glass substrate. However, since the light shielding layer 5 of the color filter 1 is composed of metals such as chromium, its light reflectance is too high, when the color filter 1 is applied to a liquid crystal display, the light shielding layer 5 will be The excessively reflected backlight produces interference phenomenon, which affects the display effect of the liquid crystal display.

【Content of invention】

In order to overcome the defect of high reflectance on one side of the black matrix light-shielding layer in the prior art, the present invention provides a black matrix with low reflectivity on both sides.

In order to overcome the defect that the reflectivity of the black matrix side of the color filter in the prior art is too high, the present invention provides a color filter, the reflectivity of the black matrix side of the color filter is relatively low.

In order to overcome the defect that the color filter in the prior art liquid crystal display device has too high reflectivity to the backlight, the present invention provides a liquid crystal display device with low reflectivity to the backlight.

The technical solution adopted by the present invention to solve the technical problem is: provide a black matrix, which includes a first anti-reflection layer, a light-shielding layer and a second anti-reflection layer, the first anti-reflection layer, light-shielding layer and the second The anti-reflection layer is arranged sequentially from bottom to top, and the second anti-reflection layer at least includes a chromium monoxide or chromium nitride film.

The technical solution adopted by the present invention to solve the technical problem is: provide a color filter, which includes a first base layer and a black matrix, and the black matrix includes a first anti-reflection layer, a light-shielding layer and a second anti-reflection layer layer, the first anti-reflection layer, the light-shielding layer and the second anti-reflection layer are sequentially arranged on the first base layer from bottom to top, and the second anti-reflection layer at least includes a chromium oxide or chromium nitride film.

The technical scheme adopted by the present invention to solve the technical problem is: provide a kind of liquid crystal display device, it comprises a first base layer, a black matrix, a liquid crystal layer and a second base layer, and this black matrix comprises a first anti-reflection layer, A light-shielding layer and a second anti-reflection layer, the first anti-reflection layer, light-shielding layer and the second anti-reflection layer are sequentially arranged on the first base layer from bottom to top, the first base layer and the second base layer are opposite The second anti-reflection layer includes at least one chromium oxide or chromium nitride film.

Compared with the prior art, the present invention has the following advantages: because the black matrix light-shielding layer of the present invention is not only provided with an antireflection layer on its lower surface, but also is provided with an antireflection film thereon, and the antireflection layer includes chromium monoxide or Chromium nitride film, which can use the principle of interference and destructive interference of reflected light on each surface to reduce the reflection of light from it, so the two sides of the black matrix have low reflectivity, and the color filter and liquid crystal display using the above black matrix The device has better optical performance due to the lower light reflectivity on the back side.

【Description of drawings】

FIG. 1 is a schematic structural diagram of a color filter in the prior art.

Fig. 2 is a schematic structural diagram of another color filter in the prior art.

Fig. 3 is a structural schematic diagram of the first embodiment of the black matrix of the present invention

FIG. 4 is a schematic structural diagram of another embodiment of the black matrix of the present invention.

Fig. 5 is a schematic diagram of the structure of the color filter of the present invention.

FIG. 6 is a schematic structural diagram of a liquid crystal display device of the present invention.

【Detailed ways】

Please refer to FIG. 3 , which is a schematic structural diagram of the first embodiment of the black matrix of the present invention. The black matrix 33 includes a first anti-reflection layer 332, a light-shielding layer 333 and a second anti-reflection layer 334, the first anti-reflection layer 332, the light-shielding layer 333 and the second anti-reflection layer 334 are sequentially arranged on a first On a base layer 34, wherein, the first anti-reflection layer 332 includes a first film layer 3321 and a second film layer 3322 which are sequentially arranged on the first base layer 34, and the refractive index of the second film layer 3322 is greater than that of the first film layer The refractive index of layer 3321. The first film layer 3321 is mainly made of chromium oxide (CrO _x , X is the atomic number ratio of O and Cr) material, and its thickness is 20-60nm; the second film layer 3322 is mainly made of chromium nitride (CrN _Y , Y is made of materials with the atomic number ratio of N and Cr, and its thickness is 20-100 nm. The light-shielding layer 333 is mainly made of chromium (Cr), and its refractive index is lower than that of the second film layer 3322 .

The second anti-reflection layer 334 is mainly composed of chromium oxide, its thickness is 20-60 nm, and its refractive index is smaller than that of the light-shielding layer 333 . The second anti-reflection layer 334 can also be made of chromium nitride, its refractive index is smaller than that of the light shielding layer 333 , and its thickness is 20-100 nm. The second anti-reflection layer 334 cooperates with the light-shielding layer 333 to reduce the reflectance of the light from one side of the second anti-reflection layer 334 by utilizing the interference and destructive principle of light reflected from each surface.

Please refer to FIG. 4 , which is a schematic structural diagram of the second embodiment of the black matrix of the present invention. The black matrix 43 includes a first anti-reflection layer 432, a light-shielding layer 433 and a second anti-reflection layer 434, the first anti-reflection layer 432, the light-shielding layer 433 and the second anti-reflection layer 434 are sequentially arranged on a first On a base layer 44 . The black matrix 43 is basically the same as the first embodiment of the black matrix of the present invention, the difference is that the second anti-reflection layer 434 includes a third film layer 4343 attached to the surface of the light shielding layer 433 and a fourth film layer 4344 thereon , it cooperates with the light-shielding layer 433 to reduce the reflectance of the light from the second anti-reflection layer 434 side by using the principle of interference and destructive interference of reflected light from each surface. In this embodiment, the refractive index of the third film layer 4343 is greater than the refractive index of the fourth film layer 4344 . The third film layer 4343 is mainly made of chromium nitride, and its thickness is 20-100 nm; the fourth film layer 4344 is mainly made of chromium oxide, and its thickness is 20-60 nm. The light shielding layer 433 has a lower refractive index than the third film layer 4343 .

Please refer to FIG. 5 , which is a schematic structural diagram of the color filter of the present invention. The color filter 30 includes a first base layer 34 , a black matrix 33 , a colored layer 32 and an ITO layer 31 . The first base layer 34 is transparent glass, the black matrix 33 includes a first antireflection layer 332, a light shielding layer 333 and a second antireflection layer 334, the first antireflection layer 332, light shielding layer 333 and the second The antireflection layer 334 is sequentially disposed on a first base layer 34 , and the first antireflection layer 332 includes a first film layer 3321 and a second film layer 3322 sequentially disposed on the first base layer 34 . The colored layer 32 includes three colored units of red, blue and green, which are arranged alternately with the black matrix 33 on the first base layer 34 . The ITO layer 31 is disposed on the surface of the colored layer 32 .

The black matrix 33 is regularly arranged in a grid pattern on the first base layer 34, and the first anti-reflection layer 332, the light-shielding layer 333 and the second anti-reflection layer 334 are formed on the first base layer through processes such as photolithography and imaging. 34, the thickness of each layer in between can be freely controlled to obtain lower reflectivity and higher OD value. The coloring layer 32 is formed on the first base layer 34 by means of pigment dispersion, and the coloring units (R, B, G) of the coloring layer 32 are repeatedly arranged at grid intervals of the black matrix 33 .

Please refer to FIG. 6 , which is a schematic diagram of a liquid crystal display device of the present invention. The liquid crystal display device includes a first base layer 34 , a black matrix 33 , a colored layer 32 , an ITO layer 31 , a liquid crystal layer 35 , a thin film transistor array 36 and a second base layer 37 . The black matrix 33 includes a first anti-reflection layer 332, a light-shielding layer 333 and a second anti-reflection layer 334, and the first anti-reflection layer 332, the light-shielding layer 333 and the second anti-reflection layer 334 of the black matrix 33 are arranged in sequence On a first base layer 34 , the first anti-reflection layer 332 includes a first film layer 3321 and a second film layer 3322 sequentially disposed on the first base layer 34 . The coloring layer 32 and the black matrix 33 are arranged alternately on the first base layer 34, and its specific design is similar to that of the color filter of the present invention. The ITO layer 31 is disposed on the surface of the colored layer 32 . The first base layer 34 and the second base layer 37 are disposed opposite to each other, and sandwich the liquid crystal layer 35 therebetween. The TFT array 36 is disposed on a side of the second base layer 37 adjacent to the liquid crystal layer 35 .

The ITO layer 31 cooperates with the thin film transistor array 36 to control the rotation of the liquid crystal molecules in the liquid crystal layer 35 with an electric field, thereby controlling whether the light from the backlight system (not shown) passes or not. The light passing through the liquid crystal layer 35 is incident on the colored layer 32 and the black matrix 33, the colored layer 32 filters the light and passes through it, and the black matrix 33 is used to block the light between the colored layers 32 to prevent light leakage, and the second The anti-reflection layer 334 cooperates with the light-shielding layer 333 to reduce the reflection of light from the backlight by using the principle of interference and destructive interference of reflected light from each surface.

Certainly, liquid crystal display device of the present invention also can replace TFT array 36 with ITO thin film, and this ITO thin film and ITO layer 31 cooperate to control the liquid crystal molecule rotation of liquid crystal layer 35; Similarly, liquid crystal display device of the present invention also can not need coloring layer 32, And the ITO layer 31 is directly covered on the first base layer 34 and the black matrix 33 .

Claims (10)

1. black matrix", it comprises one first anti-reflecting layer and a light shield layer, this light shield layer is arranged on this first reflection horizon, it is characterized in that: this black matrix" also comprises one second anti-reflecting layer, this second anti-reflecting layer is arranged on this light shield layer, and it comprises chromous oxide or chromium nitride film at least.

2. black matrix" as claimed in claim 1 is characterized in that: this first anti-reflecting layer comprises the double-layer films that refractive index is different, and presses close to the refractive index height of the film refractive index of this light shield layer than this light shield layer and another film.

3. black matrix" as claimed in claim 2 is characterized in that: this second anti-reflecting layer refractive index is less than the refractive index of this light shield layer.

4. black matrix" as claimed in claim 2 is characterized in that: this second anti-reflecting layer comprises the double-layer films that refractive index is different, and presses close to the refractive index height of the film refractive index of this light shield layer than this light shield layer and another film.

5. colored filter, it comprises one first basic unit and a black matrix", this black matrix" comprises one first anti-reflecting layer and a light shield layer, this first anti-reflecting layer and light shield layer are set in turn in this first basic unit from bottom to top, it is characterized in that: this black matrix" also comprises one second anti-reflecting layer, this second anti-reflecting layer is arranged on this light shield layer, and it comprises chromous oxide or chromium nitride film at least.

6. colored filter as claimed in claim 5 is characterized in that: this first anti-reflecting layer comprises the double-layer films that refractive index is different, and presses close to the refractive index height of the film refractive index of this light shield layer than this light shield layer and another film.

7. colored filter as claimed in claim 6 is characterized in that: this second anti-reflecting layer refractive index is less than this light shield layer.

8. colored filter as claimed in claim 6 is characterized in that: this second anti-reflecting layer comprises the double-layer films that refractive index is different, and presses close to the refractive index height of the film refractive index of this light shield layer than this light shield layer and another film.

9. liquid crystal indicator, it comprises one first basic unit, a black matrix", a liquid crystal layer and one second basic unit, this black matrix" comprises one first anti-reflecting layer, a light shield layer, wherein, this first anti-reflecting layer and this light shield layer are set in turn in this first basic unit from bottom to top, this first basic unit and this second basic unit are oppositely arranged, and this liquid crystal layer of clamping therebetween, it is characterized in that: this black matrix" also comprises one second anti-reflecting layer, this second anti-reflecting layer is arranged on this light shield layer, and it comprises chromous oxide or chromium nitride film at least.

10. liquid crystal indicator as claimed in claim 9, it is characterized in that: this liquid crystal indicator also comprises an ITO layer, a dyed layer and a thin film transistor (TFT) array, this dyed layer and this black matrix" alternately are provided with in this first basic unit, this ITO layer is arranged on this dyed layer, and this thin film transistor (TFT) array is arranged at contiguous liquid crystal layer one side of this second basic unit.

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