JPH1039132A - Production of color filter for liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for a color filter for liquid crystal display by which a color filter having excellent color characteristics, little dependence on a visual angle and high performance such as fast response of an LCD can be produced in a simple processes at a low cost. SOLUTION: A filter agent 1 comprising a photosensitive polymer material is applied on a substrate 10 in a filter agent applying process (A) and then dried in a drying process (B). Then, the filter agent 1 is irradiated with laser L1 of red light R through a mask 13 in an exposing process (C) for a red color R so that the reflected laser L1 interferes with irradiating laser L1. By this method, a R part R1 having a layer with different refractive index in the interference part is formed just under the mask hole 13a. After exposing processes (D) and (E) for green G and blue B colors are successively carried out, the filter layer is fixed in a fixing process (F). Thereby, an interference color filter 30 having the R part R1 where only red light is reflected, the G part G1 where only green light is reflected and the B part B1 where only blue light is reflected can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color filter for a liquid crystal display used for color selection of an LCD (liquid crystal display), and more particularly to a method of manufacturing an interference type and a transmission type color filter.

[0002]

2. Description of the Related Art A color filter is an important component of an LCD, and holds a key to high performance such as low cost and high speed response of the LCD. Color filters can be broadly classified into two types: absorption type color filters and interference type color filters.

An absorption type color filter utilizes light absorption of a dye or a pigment. An absorption type color filter utilizing light absorption of a dye is manufactured by photolithography by a dyeing method. That is, it is manufactured by patterning a photosensitive polymer using a mask and then dyeing it with a dye. Further, an absorption type color filter utilizing light absorption of a pigment is manufactured by photolithography using a pigment dispersion method. That is, it is manufactured by previously dispersing a pigment in a photosensitive polymer and patterning it with a mask.

As shown in FIG. 11, an interference type color filter is composed of a thin film 9a of high refractive index such as ZnS and Na3AlF6.
And the like and a low refractive index thin film 9b having a quarter-wave optical thickness are alternately laminated, and the incident light repeatedly reflects and interferes at the interface between the two types of thin films 9a and 9b. Only light of a specific wavelength is enhanced and extracted to the outside. Therefore, in order to improve the filter characteristics, it is necessary to increase the number of thin films 9a and 9b to be laminated, and there are usually about 10 layers to several tens layers.

[0005]

However, the above-mentioned conventional color filters have the following problems. Although an absorption type color filter is manufactured with high processing accuracy, the manufacturing process is complicated. FIG. 13 shows a method of manufacturing an absorption type color filter utilizing the light absorption of a pigment. That is, as shown in FIG. 13, first, a filter agent application step of applying a filter agent 11 on the black matrix substrate 10 is performed.
An oxygen shielding agent application step of applying 2 on the filter agent 11 is performed. After the drying step, an exposure step of irradiating light through the mask 13 is performed, and a developing step and a drying and fixing step are performed to form, for example, an R (red) portion 14. By repeating such a series of steps,
The G (green) portion 15 and the B (blue) portion 16 are formed, and an absorption color filter 20 covered with the overcoat agent 17 is manufactured through an overcoat agent application step and a drying step. As described above, in order to manufacture a conventional absorption type color filter, a complicated process from a filter agent application process to a drying and fixing process is performed in the R, G, and B portions 1.
It must be repeated three times for forming 4-16. For this reason, the manufacturing cost is extremely high. Further, since expensive dye materials are used inefficiently, the manufacturing cost is high. Furthermore, overcoat agent 17
Since the unevenness of the surface prevents the narrowing of the panel gap of the LCD, it has been difficult to improve the performance of the LCD such as high-speed response.

[0006] On the other hand, the interference type color filter has advantages that the filter characteristics are better and the transmittance is higher than the absorption type color filter. However, since thin films such as ZnS and Na3AlF6 are manufactured by laminating them by a film forming process such as sputtering, the manufacturing cost is extremely high.
Further, it is necessary to redesign the structure for each wavelength of the light to be filtered. Therefore, R (red), G (green), B
When manufacturing a filter of three colors (blue),
A complicated lithography process is required. Further, although not as large as the absorption type color filter, the unevenness of the surface caused by the difference in the structure hinders the high performance of the LCD. Furthermore, since the structure is such that color selection is performed by utilizing interference, the visual angle dependency is large. For this reason, when viewed differently from the design, the color characteristics deteriorate.

The present invention has been made in order to solve the above-mentioned problems, and has excellent color characteristics and L
It is an object of the present invention to provide a method of manufacturing a color filter for a liquid crystal display, which can improve the performance of a CD such as a high-speed response and can manufacture a color filter having little viewing angle dependence at low cost.

[0008]

In order to solve the above-mentioned problems, a method of manufacturing a color filter for a liquid crystal display according to the present invention comprises irradiating a photosensitive polymer material with light having a specific wavelength. By causing light to interfere in the photosensitive polymer material, an exposure step of forming a layer having a refractive index different from the refractive index of a non-interference part in an interference part where light is enhanced, and the exposure step formed in the exposure step And a fixing step of fixing the layer.

According to a second aspect of the present invention, there is provided a method of manufacturing a color filter for a liquid crystal display according to the first aspect.
The exposing step is to sequentially irradiate a plurality of lights of different wavelengths and cause each light to interfere with each other in the photosensitive polymer material, thereby forming a plurality of layers having different refractive indices on the interference portions of each light. Configuration.

According to the first aspect of the invention, in the exposure step, light of a specific wavelength is irradiated on the photosensitive polymer material,
Due to the interference, a layer having a refractive index different from that of the non-interfering portion is formed in the interfering portion. Then, in the fixing step, the layer is fixed, and the color filter is manufactured. When white light is applied to this color filter, the light of the specific wavelength repeats reflection and interference at the interface between the layers, and emerges from the white light irradiation side. Therefore, the manufactured color filter can be used as an interference type color filter.

According to the second aspect of the present invention, in the exposure step, a plurality of light beams having different wavelengths are sequentially irradiated on the photosensitive polymer material, and a plurality of layers having different refractive indexes are formed at the interference portions of the respective light beams. . Then, when white light is applied to this color filter, each light repeatedly reflects and interferes at the interface of the layer formed at the interference portion of each light, and comes out from the white light irradiation side. Therefore, the manufactured color filter can be used as an interference color filter that filters a plurality of lights simultaneously. Further, since this color filter transmits light other than the light having the different wavelength, it can be used as a transmission color filter for filtering this light.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) First, a method for manufacturing a color filter for a liquid crystal display according to a first embodiment of the present invention will be described. The present embodiment is a method for manufacturing an interference type color filter for monochromatic light, and FIG. 1 is a process diagram thereof. The same members as those shown in FIG. 13 are described with the same reference numerals. As shown in FIG. 1, the manufacturing method of the present embodiment includes a filter agent applying step A and a drying step B.
, R exposure step C, G exposure step D, B exposure step E and fixing,
This is the fixing step F. The base used in this manufacturing method is
This is a black matrix substrate 10, on which a grid or sprite black matrix line 10b is formed on a glass 10a.

First, in the filter agent application step A,
The filter agent 1 is applied on the base 10. The filter agent 1 is “OMNI-DEX” manufactured by DuPont, which is a photosensitive polymer material. Then, in the drying step B, after the applied filter agent 1 is dried, the process proceeds to the R exposure step C.

In the R exposure step C, a hologram device 2 shown in FIG. 2 is used. The hologram device 2 includes a laser oscillator 3, a mirror 4, a shutter 5, a beam expander 6, and a pedestal 7. The laser oscillator 3 has a Kr of wavelength 647 (nm).
This device is capable of selectively oscillating a (krypton) laser L1, an Ar (argon) laser L2 having a wavelength of 514 (nm), and an Ar laser L3 having a wavelength of 488 (nm). A mirror 8 having a reflecting surface facing the beam expander 6 is mounted on the base 7. R exposure step C
Then, the substrate 10 after the drying step B is fixed on the mirror 8 so that the substrate 10 is exposed between the mirror 8 and the mask 13 for exposure. Specifically, the laser L1 is oscillated from the laser oscillator 3 at a power of, for example, 500 mJ / cm 2, the laser L1 reflected by the mirror 4 is squeezed by the shutter 5, and then collimated by the beam expander 6, and the laser L1 is masked. 1
3, the light is incident on the surface of the filter agent 1 of the base 10 at an angle of 90 degrees.

[0015] As shown in FIG.
When the laser light L1 is incident on the filter material 1 of No. 0, the laser beam L1 passes through the filter material 1 and the glass 10a, reaches the mirror 8, and is reflected. Therefore, an interference phenomenon between the incident laser L1 and the reflected laser L1 occurs in the filter agent 1. By the way, as shown in FIG. 4 (a), the monomer 1a is uniformly dispersed in the matrix polymer 1b in "OMNI-DEX" manufactured by DuPont, which is the filter agent 1. Then, as described above, when the laser L1 interferes in the filter agent 1, as shown in FIG. 4 (b), the monomer 1a moves to the interference portion where the light is intensified, causing a polymerization reaction. Therefore, the concentration of the monomer 1a changes depending on the location, and the refractive index modulation occurs. That is, a large number of hatched layers of the polymerization-reacted monomer 1a 'are formed at an interval of a half wavelength (323.5 nm) of the laser L1. As a result, layers having different refractive indices are alternately stacked,
An R portion R1 having a layer of the monomer 1a 'at an interval of 323.5 nm is formed in a portion of the filter agent 1 immediately below the mask hole 13a shown in FIG. Thus, the R exposure step C in FIG. 1 is completed, and the process proceeds to the G exposure step D.

In the G exposure step D, the mask holes 13a
The laser L2 is oscillated from the laser oscillator 3 shown in FIG. 2 at a power of, for example, 30 mJ / cm 2. Thereby, similarly to the case of the laser L1, the layers of the monomer 1a 'are formed at an interval of a half wavelength (257 nm). As a result, a G portion G1 having such a layer is formed immediately below the mask hole 13a, and the B exposure step E
The transition to is performed. In the B exposure step E, as in the R exposure step C and the G exposure step D, the power is 2
By oscillating a laser L3 of 5 mJ / square centimeter from the laser oscillator 3, a half wavelength (244n
The B portion B1 having the monomer 1a 'layer at the interval m) is formed immediately below the mask hole 13a. G exposure step D
After the completion of the above, the process proceeds to the fixing and fixing step F.

The fixing and fixing step F is a step for completing the polymerization of the monomer 1a. That is, as shown in FIG. 4B, only the irradiation of the lasers L1 to L3 leaves some unreacted monomer 1a. Therefore, 100mJ
By irradiating the entire surface of the filter agent 1 with ultraviolet light UV (or visible light) of / cm 2, the unreacted monomer 1a is reacted to complete the polymerization. Further, the portion of the filter agent 1 is heated at a temperature of, for example, 120 ° C. for 2 hours to increase the refractive index modulation degree. This gives R
The interference type color filter 30 having the portion R1, the G portion G1, and the B portion B1 is manufactured.

Next, the characteristics of the interference type color filter 30 manufactured by the manufacturing method of the present embodiment will be described. As shown in FIG. 5, R part R1, G part G1, B part B1
Are irradiated with white light w from the surface side of the interference type color filter 30 in which are arranged. In the R part R1, the monomer 1
Since the layers a ′ are formed at intervals of 323.5 nm,
Incident light is reflected at the interface between the layer of monomer 1a 'and another layer,
The interference is repeated, and only the red light R of 647 nm is strengthened and emerges on the surface side of the interference type color filter 30. G
514 nm is similarly applied to the portions G1 and B1.
Only green light G and blue light B of 488 nm emerge on the surface side. That is, the interference type color filter 30 exhibits characteristics as a color filter that filters the red light R in the R portion R1, the green light G in the G portion G1, and the blue light B in the B portion B1.

FIG. 6 is a spectral characteristic diagram of the interference type color filter 30. The characteristic curves of the red light R, the green light G, and the blue light B sharply rise at 647 nm, 514 nm, and 488 nm. On the other hand, in the absorption type color filter in which the conventional pigment is dispersed, the characteristic curves of the red light R, the green light G, and the blue light B do not rise sharply as shown in FIG. Therefore, by using the interference type color filter 30 manufactured by the manufacturing method of the present embodiment, it is possible to reproduce a wider range of the chromaticity diagram than the conventional absorption type color filter. The color reproduction area can be adjusted by controlling the thickness of the interference type color filter 30. That is, the width of the characteristic curve of the red light R, the green light G, and the blue light B shown in FIG. 6 can be changed by adjusting the thickness of the filter agent 1 in the filter agent application step A.

As described above, according to the method of manufacturing a color filter for a liquid crystal display of the present embodiment, an interference type color filter 30 having good color characteristics can be manufactured. Further, since there is no need to use the overcoat agent 17 unlike the conventional absorption type color filter 20 shown in FIG. 13, no irregularities are generated on the surface of the interference type color filter 30. Therefore, by using the interference type color filter 30, it is possible to narrow the panel gap of the LCD, and to improve the performance of the LCD such as high-speed response. In addition, in order to manufacture the conventional absorption type color filter 20, a complicated process from a filter agent application process to a drying and fixing process must be repeated three times to form the R, G, and B portions 14 to 16. did not become. On the other hand, in the production of a conventional interference type color filter, a multilayer thin film having a different refractive index has to be formed by repeating sputtering or the like. For this reason, the conventional absorption-type and interference-type color filters require complicated and many steps, and the production cost is extremely high. On the other hand, in the manufacturing method of the present embodiment, as shown in FIG. 1, the R exposure step C, the G exposure step D, and the B exposure step E are performed successively, so that the R portion of the interference type color filter 30 is formed. The R1, G portion G1, and B portion B1 can be formed at once. Furthermore, R part R1, G part G1, B part B1
Even when layers having different refractive indices are formed, there is no need to repeat sputtering or the like, and they can be formed at once by exposure. Therefore, according to the manufacturing method of the present embodiment, the high-performance interference type color filter 30 can be manufactured in a small number of steps, so that the manufacturing cost can be greatly reduced.

Second Embodiment Next, a second embodiment of the present invention will be described.
A method for manufacturing a color filter for a liquid crystal display according to the embodiment will be described. The method for manufacturing a color filter for a liquid crystal display according to the present embodiment is a method for manufacturing an interference type color filter capable of reflecting and extracting a plurality of lights. This manufacturing method is shown in FIG.
Filter agent application step A in which filter agent 1 is applied to filter agent 0
Drying step B for drying the filter agent 1;
The point of including the fixing step F is the same as that of the first embodiment, except that the exposure step between the drying step B and the fixing and fixing step F is different. Therefore, in order to avoid redundant description, only the exposure step will be described here.

In the exposure step for producing an interference type color filter capable of reflecting the red light R and the green light G, after the drying step B is completed, first, a laser L1 having a power of, for example, 200 mJ / cm 2 is applied to the filter of the substrate 10. Irradiate Agent 1. Thus, a layer of the monomer 1a 'is formed on the filter agent 1 at an interval of a half wavelength (323.5 nm) of the laser L1. Thereafter, when a laser L2 having a power of, for example, 10 mJ / cm 2 is irradiated on the filter agent 1, a half wavelength (2
A layer of the monomer 1a 'is formed at an interval of 57 nm).
That is, since the wavelengths of the laser L1 and the laser L2 are different, as shown in FIG. G2 is formed. Thereafter, the process proceeds to the fixing and fixing process F,
By irradiating with UV light (or visible light) and heating,
By completing the polymerization, the interference type color filter 31
Is manufactured.

The interference type color filter 31 manufactured as described above has a white light w as shown in FIG.
Is irradiated, the red light R is reflected by the layer R2, and the layer G2
Reflects the green light G, and two lights of red light R and green light G are extracted. FIG. 8 is a spectral characteristic diagram of the interference type color filter 31. As shown in FIG. 8, according to the interference type color filter 31, 647 nm, 514 n
m, the characteristic curves of the red light R and the green light G rising sharply can be obtained.
It can be seen that the color characteristics are very excellent.

In the exposure step for producing an interference type color filter capable of reflecting the red light R and the blue light B, a laser L1 is applied to the filter agent 1 and then to a laser L3. As a result, as shown in FIG. 7 (b), the layer R of the monomer 1a 'was
2 is formed, and a layer B2 of the monomer 1a 'is formed at an interval of 244 nm by the laser L3. After a while, fixation,
By performing the fixing step F, the interference type color filter 32 that reflects the two lights of the red light R and the blue light B is manufactured. Similarly, in an exposure step for manufacturing an interference type color filter capable of reflecting green light G and blue light B, laser L2 and laser L3 are irradiated on the filter agent 1 so that the filter agent 1 shown in FIG.
(C), the layer G2 and the layer B2 are formed on the filter agent 1.

In a conventional interference type color filter, since it is uniquely designed for a specific wavelength, it is difficult to adopt a structure for simultaneously filtering a plurality of lights. However, according to the manufacturing method of the present embodiment, as described above, the filter agent 1 can be multiple-exposed with a plurality of laser beams before the fixing and fixing step F, so that the plurality of beams can be The interference type color filter 31 having a structure for filtering at the same time can be easily manufactured.

As shown in FIG. 7, when white light w is irradiated, the interference type color filters 31 to 33 cause red light R and green light G, red light R and blue light B, green light G
Reflecting the blue light B toward the surface side means that the blue light B, the green light G, and the red light R are reflected by the interference type color filter 3.
It means that the light passes through 1-33 and comes out on the back side.
Therefore, as shown in FIG. 9, when white light w is irradiated from one side of the interference type color filters 31 to 33, blue light B, green light G, and red light R can be extracted on the other side, and the interference type color filters 31 to 33 can be extracted. 31 to 33 can be used as transmission color filters. That is,
The manufacturing method of the present embodiment employs the interference type color filter 31.
-33 as well as transmission color filters 31-33
Can also be manufactured. The transmission color filters 31 to 33 manufactured in this manner do not take out light using reflection and interference, but take out blue light B, green light G, and red light R transmitted through the color filters. Almost no dependencies. The other configuration, operation, and effect are the same as those of the first embodiment, and the description thereof is omitted.

The present invention is not limited to the above embodiment, and various modifications and changes can be made without departing from the scope of the invention. For example, in the above embodiment, the hologram optical system shown in FIG. 2 is applied as the hologram optical system for causing the laser light to interfere in the filter agent 1, but a hologram optical system as shown in FIG. 10 may be applied.
This hologram optical system is a commonly used hologram optical system, and it is possible to adjust the way of interfering with the laser light in accordance with the method of using the color filter (such as the viewing direction). That is, the laser light L from the laser light source 40 is transmitted to the half mirror 42 via the shutter 41, the laser light L reflected by the half mirror 42 is used as the reference light L, and the laser light L transmitted through the half mirror 42 is used as the object light. L. Then, the reference light L is expanded by the spatial filter 43 and the collimation lens 44
And collimates the light into the mirror 45. On the other hand, the object light L is reflected by the mirror 46, and is divided into a spatial filter 47, a collimation lens 48, and a projection lens 49.
Through the condenser lens 50. As a result, the object light L irradiates one side of the filter agent 1 via the condenser lens 50 and the reference light L irradiates the other side of the filter agent 1 at an angle of the mirror 45. Therefore, the object light L and the reference light L interfere with each other in the filter agent 1. By changing the angle of the mirror 45, it is possible to adjust the manner of causing the interference. In the first embodiment, the exposure is performed in the order of the R exposure step C, the G exposure step D, and the B exposure step E, but the order of these steps is arbitrary. Similarly, the irradiation order of the two laser beams in the second embodiment is arbitrary. Further, in the above-described embodiment, “OMNI-DEX” manufactured by DuPont was used as the photosensitive polymer material. However, the present invention is not limited to this. Any material can be used as long as it can fix and fix the difference in rate.

[0028]

As described above in detail, according to the first aspect of the present invention, a layer having a different refractive index is formed in an interference portion only by irradiating a photosensitive polymer material with light of a specific wavelength and fixing the same. Since they can be formed at one time, the number of color filter manufacturing steps can be reduced, and as a result, there is an excellent effect that the manufacturing cost can be reduced.
In addition, since an overcoat agent or the like is not applied to the surface of the color filter, the use of this color filter makes it possible to improve the performance of the LCD such as high-speed response.

According to the second aspect of the present invention, it is possible to easily manufacture an interference type color filter capable of simultaneously filtering a plurality of lights, which has been difficult in the conventional method of manufacturing an interference type color filter. There is. Further, a transmission type color filter having almost no viewing angle dependence can be manufactured.

[Brief description of the drawings]

FIG. 1 is a process chart of a method for manufacturing a color filter for a liquid crystal display according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a hologram device applied in the exposure step of FIG.

FIG. 3 is a cross-sectional view illustrating interference of laser light during exposure.

FIG. 4 is an explanatory diagram showing a polymerization state of a filter agent;
4A shows an initial state, FIG. 4B shows a state at the time of exposure, and FIG. 4C shows a state at the time of fixing and fixing.

FIG. 5 is a schematic sectional view showing a filtering action of the manufactured interference type color filter.

FIG. 6 is a spectral characteristic diagram of an interference type color filter.

FIG. 7 is a schematic cross-sectional view illustrating a filtering action of an interference type color filter manufactured by a method of manufacturing a color filter for a liquid crystal display according to a second embodiment of the present invention, and FIG. 7B shows filtering of red light and blue light, and FIG. 7C shows filtering of green light and blue light.

FIG. 8 is a spectral characteristic diagram of an interference type color filter for red light and green light.

9A and 9B are schematic cross-sectional views illustrating a filtering operation of a transmission type color filter, wherein FIG. 9A illustrates filtering of blue light, FIG. 9B illustrates filtering of green light, and FIG. (C) shows filtering of red light.

FIG. 10 is a schematic view showing another example of the hologram optical system.

FIG. 11 is a schematic view showing a conventional interference type color filter.

12 is a spectral characteristic diagram of the interference type color filter of FIG.

FIG. 13 is a process chart showing a conventional method for producing an interference type color filter.

[Explanation of symbols]

1 ... Filter agent, 1a ... Monomer, 1a
': Polymerized monomer, 10: base, 30
... interference type color filter, A ... filter agent application step, C ... R exposure step, D ... G exposure step, E ... B exposure step, F ... fixing and fixing step, L1, L2, L3 ... Laser.

Claims (2)

[Claims] 1. A layer having a refractive index different from the refractive index of a non-interfering portion by irradiating light of a specific wavelength to a photosensitive polymer material and causing the light to interfere in the photosensitive polymer material. A method for manufacturing a color filter for a liquid crystal display, comprising: an exposing step of forming a layer on an interference portion where light is intensified; and a fixing step of fixing the layer formed in the exposing step. 2. The method for manufacturing a color filter for a liquid crystal display according to claim 1, wherein the exposing step includes sequentially irradiating a plurality of lights of different wavelengths, and each light is irradiated within the photosensitive polymer material. A method for producing a color filter for a liquid crystal display, wherein a plurality of layers having different refractive indexes are formed in an interference portion of each light by causing interference.