JPH0915420A - Color filter for color liquid crystal projector and its production - Google Patents

Abstract

PURPOSE: To improve heat resistance and weatherability by alternately laminating high-refractive index material and low-refractive index materials to multiple layers on a transparent substrate and providing these layers with color filter patterns by multilayered thin film interference filters which are respectively specific in the spectral transmittance of peak regions of red, green and blue, respectively, and have low light absorbance. CONSTITUTION: Light transparent color pattern layers L by pixel patterns of the same planar patterns B, G, R are formed on three pixel pattern regions Pc disposed at each of color display pixel regions CPC on the transparent substrate. The film thicknesses and number of laminated layers of the respective laminated thin films are respectively set adequately for each of the respective colors, by which the patterns B, G, R of the prescribed patterns are formed. The transmittance of the light transmitted through the patterns B, G, R is 85 to 95% at least in all of the spectral transmittance of the peak regions of the respective colors. The color filter patterns by the interference filters having the low light absorbance in the patterns B, G, R are thus obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reflects a television image recorded by a video camera (television camera), a recorded video image, or a video image obtained by image-converting a photographic image captured by a photographic camera by video recording. TECHNICAL FIELD The present invention relates to a color filter for a color liquid crystal projector for use in a color liquid crystal projector for enlarging and projecting the image on a projection screen or a transmission type projection screen for viewing, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Recently, audio in the information society
With the progress of visualization, a viewing style in which a television image or a recorded video image is enlarged and projected on a reflective or transmissive projection screen to enjoy image information has become widespread.

In order to enlarge and project a television image or a recorded video image on a reflective or transmissive projection screen, a color television image projector of a CRT display system or a liquid crystal display system is used.

In the color television image projector of the above color liquid crystal display system, a single magnifying optical lens system is arranged on the front surface of a single color liquid crystal television screen and an illumination light source is arranged on the rear surface thereof, and through the lens system. There is a single-lens system color liquid crystal projector that projects a color liquid crystal television screen on a projection screen in an enlarged manner.

In the color liquid crystal display type color television image projector, three monochrome liquid crystal television screens are provided in front of each of red, green, green and blue of each screen. A color filter of a color corresponding to the color component and a magnifying optical lens system are arranged in this order, an illumination light source is arranged on the rear surface of each of the three monochrome liquid crystal television screens, and each of them is arranged through the three lens systems. There is a three-lens system color liquid crystal projector that is designed to enlarge and project a monochrome liquid crystal television screen on a projection screen.

A color liquid crystal television screen used in the above-mentioned single-lens type color liquid crystal projector has a color filter pattern of three colors of R, G, and B formed on each pixel of a television image and an electric charge. Then, a color image is output and displayed by a color liquid crystal display panel in which liquid crystals whose molecules are oriented from translucent to light-shielding or from light-shielding to translucent are regularly arranged in a ratio of 1: 1.

The three monochrome liquid crystal television screens used in the above-mentioned three-lens system color liquid crystal projector are
A monochrome (black and white) image of each color component corresponding to each of the three color component images of R, G, and B is displayed on a monochrome liquid crystal display panel, and a color filter of the color corresponding to the color component arranged on each panel is used. The color image is output and displayed.

The color liquid crystal projector is a CRT.
Unlike a color projector that uses a display method, the main body of the color liquid crystal display panel that is used does not have a fluorescent light emitting function, such as a cathode ray tube. Various illumination light sources are arranged.

[0009]

Generally, each of the R, G, and B color filters used in the color liquid crystal display panel or the monochrome liquid crystal display panel of the above color liquid crystal projector has a dyeing resin (gelatin etc.) formed by a dye. Color filters are colored by dyeing methods that use dyeing, pigment dispersion methods that use a pigment-dispersed photoresist, printing methods that print with printing ink, etc.Currently, these organic color filters are the mainstream. Has become.

However, since the above organic color filters use dyes and pigments, red dyes and pigments have no heat resistance and weather resistance, and are resistant to chemicals such as acids and alkalis. Tend to be relatively weak.

The dyeing method lacks heat resistance and light resistance, and the printing method has a pattern size (size in plan view) of 6
It is about 0 to 100 μm and lacks miniaturization.

Further, in the dyeing method, the pigment dispersion method, and the printing method, the spectral transmittance in the B, G, and R peak transmission regions of the color filter is low, and particularly, the peak transmission of blue (blue) and green (green) is low. Spectral transmittance in the region is 80% or less,
Red (red) is also as low as 85% or less, which is insufficient for improving the light efficiency such as the optical gain of the backlight (illumination light).

Therefore, in the color liquid crystal projector using the color filter by the dyeing method, the pigment dispersion method or the printing method, the heat generated from the powerful illumination light source and the deterioration of the color filter due to the temperature and humidity fluctuations of the atmosphere occur relatively. easy.

By the way, as a color filter resistant to heat, temperature and humidity, and resistant to chemicals such as acids and alkalis, thin films of inorganic compounds have been laminated in the past and colored by spectral transmission through the multilayer thin films. There is a highly transmissive interference filter (multilayer thin film interference filter), and a manufacturing method thereof is disclosed in, for example, JP-A-59-152407.
JP-A-1-172905, JP-A-5-45514
Japanese Patent Application Laid-Open No. 5-45515 and the like.

However, these heat-resistant, weather-resistant and chemical-resistant color filters are used for color image detection sensors (CCD), but not for color liquid crystal projectors. Is the current situation.

The present invention is an inorganic-based material having good heat resistance and weather resistance, which has a good spectral transmittance due to the alternate multi-layer lamination of a high light refractive index material and a low light refractive index material which does not depend on a dyeing method, a pigment dispersion method or a printing method. It is an object of the present invention to provide a color filter using a multilayer thin film interference filter for a color liquid crystal projector which is colored by the multilayer film method.

[0017]

The first aspect of the present invention is to provide a high-refractive-index material and a low-refractive-index material, which are alternately laminated in multiple layers, on a transparent substrate, and to spectrally analyze peak regions of red, green, and blue, respectively. A color filter for a color liquid crystal projector, comprising a color filter pattern of a multilayer thin-film interference filter having a low light absorptance and a transmittance of 85% or more.

Next, a second invention of the present invention provides a color filter pattern by the multilayer thin film interference filter of the color filter for color liquid crystal projector of the first invention,
A method of manufacturing a color filter for a color liquid crystal projector, which is characterized by patterning using a lift-off method.

Next, a third invention of the present invention provides a color filter pattern by the multilayer thin film interference filter of the color filter for color liquid crystal projector of the first invention,
A method of manufacturing a color filter for a color liquid crystal projector, which comprises patterning using a dry etching method.

[0020]

The color filter for a color liquid crystal projector according to the first aspect of the present invention will be described in detail below with reference to the example of FIG.

FIG. 1 is a side sectional view of a color filter for a color liquid crystal projector of the first invention, that is, a color filter of a color liquid crystal display panel used for a so-called color liquid crystal projector.

On the surface of the transparent substrate 1 (glass substrate), in three pixel pattern regions Pc (pixel regions) provided for each color display pixel region CPc, a blue pattern B and a green ( Green) pattern G,
Red (red) pattern R pixel pattern (pixel)
The light-transmitting color pattern layer L is formed.

Patterns B, G, and R are a thin film made of a material having a high photorefractive index (for example, photorefractive index n ≧ 2.0),
This is a pattern in which thin films made of a low light refractive index material (for example, light refractive index n ≦ 1.5) are alternately laminated in multiple layers.

Titanium oxide (T
iO ₂ , photorefractive index; 2.40), zinc oxide (ZnO),
Zinc sulfide (ZnS) or the like is used, and as the low light refractive index material, silicon dioxide (SiO ₂ , light refractive index; 1.4
6), silicon monoxide SiO, magnesium fluoride (MgF
₂ ) etc. are used.

Patterns B, G, and R, respectively, are PVD (physical v) using heated steam of these materials.
A thin film is laminated in multiple layers on the transparent substrate 1 by an ion assisted vapor deposition method such as a sputtering method, an ion plating method, an ion beam vapor deposition method, etc., to form a pattern.

It is appropriate that the thickness of each thin film is approximately the same λ / 4 (λ; wavelength of projector illumination light source).
The number of laminated thin films is appropriately in the range of 7 to 30 layers, or in the range of 9 to 30 layers.

The patterns B, G, and R are made to have different light refractive indices between the thin film layers of the patterns B, G, and R, respectively. White light (scattered light or regular divergent light from an optical lens system) is spectrally transmitted light that passes through the patterns B, G, and R, and the photorefractive index at the thin film surface or multilayer thin film interface of the patterns B, G, and R. Is an interference filter that is separated into surface reflected light caused by the difference of
A blue pattern B, a green pattern G, and a red pattern R of a predetermined color are formed by appropriately setting the film thickness and the number of layers of the laminated thin films for each color.

Further, regarding the transmittances of light transmitted through the patterns B, G, and R, the spectral transmittances in the peak regions of blue, green, and red are all 85% to 90% or more. , Patterns B, G, and R are color filter patterns formed by an interference filter having a low light absorptance.

In the color filter of the present invention, the vacuum is provided between the transparent substrate 1 and the filter pattern layer L or on the surface side of the filter pattern layer L along the boundary portions of the patterns B, G and R, respectively. The light-shielding thin film (opaque thin film) formed by the vapor deposition method or the sputtering vapor deposition method is patterned by the photolithography method, the photoetching method, or the like, and a thin black matrix pattern of chromium, chromium oxide, or aluminum is provided. It is omitted in the drawing.

Next, a method of manufacturing a color filter for a color liquid crystal projector of the second invention will be described in detail below with reference to an embodiment of manufacturing steps shown in the side sectional views of FIGS.

First, (a) on the transparent substrate 1 made of glass,
A heat resistant photoresist is applied to form a resist layer 2.

On the surface of the transparent substrate 1, thin line-shaped light-shielding black such as stripes or meshes is preliminarily provided along a portion corresponding to a boundary between filter patterns B, G, and R to be formed later. A matrix pattern (not shown) is formed in advance.

The pattern of the black matrix pattern is formed by forming a light-shielding thin film layer of chromium, chromium oxide, aluminum or the like on one surface of the transparent substrate 1 by a vacuum deposition method, a sputtering method or the like, and then performing a photolithography method. The photo-shielding thin film layer is patterned into a light-shielding black matrix pattern by performing a pattern exposure process, a development process, a pattern etching process, etc. using a photoresist and a lift-off material by a photo etching method or the like.

Subsequently, for each color display pixel pattern area CPc, a pixel pattern area Pc corresponding to, for example, the pattern G of the first color is pattern-exposed on the resist layer 2 and subjected to development processing, thereby (b) being transparent. A resist pattern 2a is patterned on the substrate 1.

Subsequently, (c) the transparent substrate 1 and the resist pattern 2a are alternately formed on the transparent substrate 1 and the resist pattern 2a by an ion assist method using a high light refractive index material and a low light refractive index material based on a predetermined film thickness and the number of layers. A green layer G ₀ (for example, a layer thickness of about 1.9 μm) is formed by laminating a plurality of thin films.

Then, (d) the resist pattern 2a is peeled off (lifted off) from the transparent substrate 1 to form each color display pixel pattern region C on the transparent substrate 1.
A green pattern G is formed in the pixel pattern area Pc for each Pc.

Next, (e) a photoresist is applied over the entire surface of the transparent substrate 1 and the green pattern G, and pattern exposure is performed to form a resist pattern 3a.

Subsequently, (f) the transparent substrate 1 and the resist pattern 3a are alternately formed on the transparent substrate 1 and the resist pattern 3a by an ion assist method using a high light refractive index material and a low light refractive index material based on a predetermined film thickness and the number of layers. A red layer R ₀ (for example, a layer thickness of about 1.5 μm) is formed by laminating a plurality of thin films.

Subsequently, (g) the resist pattern 3a is peeled and removed (lifted off) from the transparent substrate 1 to form each color display pixel pattern region C on the transparent substrate 1.
A red pattern R is pattern-formed in the pixel pattern area Pc for each Pc.

Next, (h) a photoresist is applied over the entire surface of the transparent substrate 1 and the green pattern G and the red pattern R, and pattern exposure is performed to form a resist pattern 4a.

Next, (f) the transparent substrate 1 and the resist pattern 4a are alternately formed on the transparent substrate 1 and the resist pattern 4a by an ion assist method using a high photorefractive index material and a low photorefractive index material based on a predetermined film thickness and the number of layers. A blue layer B ₀ (for example, a layer thickness of about 1.10 μm) is formed by laminating a plurality of thin films.

Subsequently, (j) the resist pattern 4a is peeled off (lifted off) from the transparent substrate 1 so that each color display pixel pattern region C on the transparent substrate 1 is removed.
A blue pattern B is formed in the pixel pattern area Pc for each Pc.

As a result, the color filter pattern layer L including the blue pattern B, the green pattern G, and the red pattern R colored by the interference film is formed on the transparent substrate 1 for each color display pixel pattern region CPc. A color filter for the arranged color liquid crystal projector is manufactured.

Finally, if necessary, an overcoat method in which a transparent synthetic resin is uniformly applied to the surface of the patterned color filter pattern layer L, or the surface of the color filter pattern layer L or the color filter pattern The surface of the overcoat on the surface of the layer L is smoothed by using a surface polishing method in which it is polished smoothly by a buffing method or the like.

In the color filter manufacturing method, the blue pattern B, the green pattern G, and the green pattern G are formed on the transparent substrate 1 on which the black matrix pattern is formed in advance.
Although the red pattern R is formed respectively, the present invention is not limited to this, and the blue pattern B, the green pattern G, and the red pattern R are respectively formed on the transparent substrate 1. After forming
Alternatively, a black matrix pattern may be formed after overcoating each of the patterns B, G, and R.

Next, a method of manufacturing a color filter for a color liquid crystal projector according to a third aspect of the invention will be described with reference to an embodiment of manufacturing steps shown in the side sectional views of FIGS. 3 (a) to (j) and 4 (a) to (d). Will be described in detail below.

First, on the transparent substrate 1 made of glass in FIG. 3 (a), a high light refractive index material and a low light refractive index material are used alternately by an ion assist method based on a predetermined film thickness and the number of layers. By forming thin films in multiple layers on the blue layer B
₀ (for example, a layer thickness of about 1.10 μm) is laminated.

Subsequently, (b) an etching mask layer 5 is formed on the blue layer B ₀ by sputtering using a metal material such as chromium metal (Cr), and then (c) a photoresist is formed on the etching mask layer 5. Apply layer 6.

Then, (d) by photolithography, the photoresist layer 6 is pattern-exposed for each color display pixel pattern region CPc, for example, a pixel pattern region Pc corresponding to the pattern G of the first color, and developed. By processing, the resist pattern 6a is patterned.

Subsequently, (e) the resist pattern 6a is used as a mask pattern to etch the lower metal etching mask layer 5 using a metal etching etchant.

Then, (f) the resist pattern 6a is removed with an organic solvent to form a metal etching mask pattern 5a on the blue layer B ₀ .

Subsequently, (g) dry etching (reactive ion etching) is performed on the blue layer B ₀ from above the etching mask pattern 5a to form an intermediate portion of the blue layer B ₀ for each color display pixel pattern region CPc. The partial pixel pattern area Pc is removed.

Subsequently, (h) thin films are alternately formed on the etching mask pattern 5a by an ion assist method using a high photorefractive index material and a low photorefractive index material based on a predetermined film thickness and the number of layers. The green layers G ₀ (for example, a layer thickness of about 1.9 μm) are formed by laminating in multiple layers.

Subsequently, (i) the metal etching mask pattern 5a is peeled off from the blue layer B ₀ by using a metal etching etchant, and each color display pixel pattern region CPc on the transparent substrate 1 is removed. In the pixel pattern region Pc, a green pattern G and a blue layer B _{0 on} both sides thereof are provided.
Is patterned.

Next, (j) a metal etching mask layer 7 is formed by sputtering on the entire surface of the green pattern G formed on the transparent substrate 1 and the blue layer B ₀ on both sides thereof.

Then, after applying a photoresist layer on the etching mask layer 7, the photoresist layer is pattern-exposed and developed to form a resist pattern, and the resist pattern is used as an etching mask pattern to form a metal. The etching mask layer 7 made of is etched with a metal etching etchant.

Then, as shown in FIG. 4A, an etching mask pattern 7a is formed on the green pattern G for each color display pixel pattern area CPc and the blue layer B ₀ on one side thereof.

Then, dry etching (reactive ion etching) is performed on the blue layer B ₀ on one side from above the etching mask pattern 7a in FIG. 4B.
The blue layer B ₀ on one side is removed, and the blue pattern B on the other side.
Is patterned.

Subsequently, from the etching mask pattern 7a and the transparent substrate 1 shown in FIG. 4 (c), a high photorefractive index material and a low photorefractive index material are used to obtain a predetermined film thickness and number of layers by an ion assist method. The red layers R ₀ (for example, a layer thickness of about 1.5 μm) are laminated by alternately laminating the thin films in multiple layers.

Subsequently, the etching mask pattern 7a shown in FIG. 4 (d) is removed from above the blue pattern B and the green pattern G by using an etchant for metal etching, so that each color display pixel pattern is formed on the transparent substrate 1. A color filter for a color liquid crystal projector is manufactured in which a color filter pattern layer L including a blue pattern B, a green pattern G, and a red pattern R, which are colored by the interference film in each region CPc, is arranged.

Finally, if necessary, an overcoat method in which a transparent synthetic resin is uniformly applied to the surface of the patterned color filter pattern layer L, or the surface of the color filter pattern layer L or the color filter pattern The surface of the overcoat on the surface of the layer L is smoothed by using a surface polishing method in which the surface is smoothly polished by a buffing method or the like.

FIG. 5 is a schematic side view of a color liquid crystal projector for explaining an example of use of the color filter according to the multilayer film method of the present invention.

The color filter of the present invention having the color filter pattern layer L formed by the multilayer method on one surface of the transparent substrate 1 has the transparent overcoat 8 having a smooth surface on the surface of the pattern layer L.

A transparent electrode (not shown) is provided on the surface of the overcoat 8, and a transparent substrate 21 (counter electrode substrate) and a transparent electrode 21a (counter electrode) are provided in parallel with and spaced from and facing the electrode. One of the electrodes facing each other is a matrix pattern electrode having a shape corresponding to the filter patterns B, G, and R.

A liquid crystal 22 is filled and sealed between the electrode on the surface of the overcoat 8 and the counter electrode 21a so as to be spaced apart from each other, and the liquid crystal corresponding to the driving charge amount based on the image display signal applied between both electrodes. Reference numeral 22 changes the state of light transmission or non-transmission to drive operation.

Further, depending on the type of the liquid crystal 22 used, an alignment plate (not shown) for aligning the liquid crystal is provided as necessary so as to be in contact with the liquid crystal 22.

From the counter electrode 21a side or the color filter side, a light flux from the illumination light source 11 is passed through a light diffusing plate, a light collecting Fresnel lens plate (convex lens plate), a collimator lens, etc. (not shown). The light flux 11a of the color display image light that has been irradiated with 11a and is driven corresponding to the electric charge applied between both electrodes and has passed through the liquid crystal 22 for image display operation and the color filter of the present invention is the magnifying optical lens system 12.
It is enlarged through the (convex lens system) and projected onto a projection screen surface such as a predetermined reflection type screen or transmission type screen.

Specific examples of the method of manufacturing a color filter for a color liquid crystal projector according to the present invention will be described below.

Example 1 A transparent substrate made of glass was coated with a photoresist by a spin coating method, and then a photolithography method was used to form a transparent color filter pattern (for example, a green pattern) of a multilayer thin film interference of the first color. A resist pattern having a film thickness of about 3.4 μm was patterned on the non-formation part of G). (See FIG. 2 (b))

As the photoresist used for the resist pattern, it has a high resolution and clay is relatively high.
A heat resistant photoresist capable of forming a thick film was used, for example, FH5600F (manufactured by Fuji Hunt Co., Ltd.) having a heat resistant temperature of about 130 ° C. and a characteristic of clay of about 56 cps.

Subsequently, thin films of a high photorefractive index material and a low photorefractive index material are alternately laminated on the patterned resist pattern by an ion assisted vapor deposition method to form a total film thickness. About 2.0 μm (strictly speaking,
A green layer serving as a first-color multilayer interference filter having a thickness of 1.94 μm) was formed. (See Fig. 2 (c))

The layer formation is carried out by using the ion assisted vapor deposition method. The ultimate vacuum pressure is about ^10.sup.-4 Pa as the vapor deposition conditions, and Ar gas (argon gas) as O 2 is ionized gas.
Kafman type ion gun (made by Syncron) at a gas flow rate of 7 SCCM using a gas mixed with ₂ % (oxygen).
And was irradiated with an output of 300 eV.

Subsequently, the resist pattern formed on the non-formation portion of the color filter pattern (for example, green pattern G) of the first color multilayer thin film interference is stripped with a neutralizing solvent (or organic solvent). After removing (lifting off), the green layer on the resist pattern was removed from the transparent substrate to form a green pattern. (Figure 2
(See (d))

A microposit, remover 1165 (manufactured by Shipley Co.) was used as the neutralizing solvent to obtain about 9
The resist pattern was completely stripped and removed at 0 ° C. for 20 minutes.

Then, a resist pattern was similarly formed on the non-formation portion (including the green pattern G) of the color filter pattern (for example, the red pattern R) of the second color multilayer thin film interference. (See Fig. 2 (e))

Subsequently, thin films of a high-light refractive index material and a low-light refractive index material are alternately laminated on the patterned resist pattern by an ion assisted vapor deposition method, Total film thickness is about 1.5 μm
A red layer serving as a multilayer interference filter for the second color (strictly speaking, 1.54 μm) was formed. (See Fig. 2 (f))

Titanium dioxide (TiO ₂ ) was used as the high light refractive index material, the rate was 1.0 Å / sec, oxygen (O ₂ ) was used as the backfill gas, about 85 SCCM, and the vacuum pressure was 3 × 10 ^-2 Pa. It was carried out at a partial pressure of. Also, silicon dioxide (SiO ₂ ) was used as the low light refractive index material, the rate was 2.0Å / sec, the backfill gas was not used, and the vacuum pressure was 3
It was carried out at × 10 ⁻³ Pa.

Subsequently, the resist pattern formed on the non-formation portion of the color filter pattern (for example, the red pattern R) of the second color multilayer thin film interference is similarly subjected to a neutralizing solvent (or organic solvent). Then, the red layer on the resist pattern is removed from the transparent substrate, and the red pattern R is changed to the green pattern G.
Patterned adjacent to. (See Fig. 2 (g))

Subsequently, in the non-formation portion (including the green pattern G and the red pattern R) of the color filter pattern (for example, the blue pattern B) of the third-color multilayer thin film interference, similarly. A resist pattern was patterned. (See Figure 2 (h))

Subsequently, thin films of a high light refractive index material and a low light refractive index material are alternately laminated on the patterned resist pattern by an ion assisted vapor deposition method, Total film thickness is about 1.0 μm
A blue layer serving as a multilayer interference filter for the third color (strictly, 1.08 μm) was formed. (See Figure 2 (i))

Subsequently, the resist pattern formed on the non-formation portion of the color filter pattern (for example, the blue pattern R) of the third-color multilayer thin film interference is similarly subjected to a neutralizing solvent (or organic solvent). Then, the blue layer on the resist pattern is removed from the transparent substrate, and the blue pattern R is changed to the green pattern G.
A pattern was formed adjacent to, to obtain a color filter for a color liquid crystal projector by the multilayer thin film interference of the present invention. (See FIG. 2 (j))

If necessary, the pattern surface of the color filter may be overcoated with a heat-resistant transparent synthetic resin (epoxy resin, amide resin) or a surface polishing method by buffing. And then smoothed.

Example 2 A thin film made of a high light refractive index material and a low light refractive index material was alternately laminated on a transparent substrate made of glass by a sputtering method to have a total film thickness of about 1 A blue layer was formed as a color filter pattern (for example, a blue pattern B) of multi-layer thin film interference having a transparency of 0.0 μm (strictly 1.08 μm). (See FIG. 3A) As the vapor deposition conditions, the ultimate vacuum pressure was 10 ⁻⁴ Pa and the heating temperature of the transparent substrate was 250 to 300 ° C. Further, titanium dioxide (TiO ₂ ) was used as the high-refractive index material, a rate of 1.0 Å / sec, and a gas of a mixture of argon gas and 10% of oxygen (O ₂ ) was used as a backfill gas, and a vacuum pressure (2 × It was carried out at a partial pressure of 10 ⁻³ Torr). Further, silicon dioxide (SiO ₂ ) is used as the low light refractive index material, a rate of 1.0 Å / sec is used, and a gas in which 10% of oxygen (O ₂ ) is mixed with argon gas is used as the backfill gas. It was carried out at a partial pressure of × 10 ⁻³ Torr).

Subsequently, chromium metal (Cr) was deposited on the entire surface of the blue layer by a sputtering method to a film thickness of about 2000 Å to form a dry etching mask layer. (Fig. 3
(See (b))

Subsequently, a photoresist was applied as a wet etching mask layer by spin coating on the entire surface of the dry etching mask layer. (See FIG. 3 (c))

Then, by photolithography, a film having a thickness of about 3.4 μm is formed on a portion where the color filter pattern (for example, green pattern G) which is transparent to the interference of the first-color multilayer thin film of the wet etching mask layer is not formed. A wet etching resist pattern was patterned. (Fig. 3
(See (d))

Subsequently, the wet etching resist pattern was used as a wet etching mask, and the ceric ammonium nitrate solution was used as an etchant to remove the first-color pattern (eg, green pattern G) forming portion of the dry etching mask layer by etching. (See FIG. 3 (e))

Subsequently, the wet etching resist pattern was dissolved and removed with an organic solvent to form a dry etching mask pattern of chromium metal on the blue layer. (See Fig. 3 (f))

Then, the first-color pattern (for example, green pattern G) forming portion of the blue layer was removed by etching from the dry etching mask pattern by a dry etching method. (Refer to FIG. 3 (g)) The dry etching is performed by reactive ion etching, and C ₂ F ₆ gas (or HF gas) is used as the etching condition in the reaction chamber at a flow rate of 10 SCCM and a gas pressure of 1.2 Pa. It was applied for about 1 hour under the condition of 0.25 W / cm ² to the transparent substrate introduced and installed on the electrode.

Successively, thin films of a high light refractive index material and a low light refractive index material are alternately laminated on the dry etching mask pattern made of chromium metal in the same manner as the blue layer by a sputtering method. As a result, a green layer was formed as a color filter pattern (for example, the first-color green pattern G) of transmissive multilayer thin film interference having a total film thickness of about 2.0 μm (strictly speaking, 1.94 μm). (Fig. 3
(See (h))

Subsequently, the dry etching mask pattern made of chromium metal on the blue layer is dissolved and removed with a diammonium cerium nitrate solution (etchant) (ultrasonic wave is also used as needed), and 1 is formed on the transparent substrate. A green color pattern G was formed. (See Figure 3 (i))

Subsequently, a dry etching mask layer made of chromium metal was formed on the entire surface of the blue layer and the green pattern G of the first color by a sputtering method. (Fig. 3
(See (j))

Subsequently, similarly to the above, a photoresist is applied to the entire surface of the dry etching mask layer made of chromium metal to form a wet etching mask layer, and the first color green pattern G and 2 are formed by photolithography.
After forming a wet etching mask pattern on the portion where the blue pattern B of the color is formed, the dry etching mask layer of the lower chromium metal is wet-etched by using the diammonium cerium nitrate solution as an etchant to obtain the green color of the first color. A dry etching mask pattern was formed on the pattern G and on the formation portion of the second color blue pattern B. (See Fig. 4 (a))

Subsequently, the third-color pattern (for example, red pattern R) forming portion of the blue layer is removed by etching from above the dry-etching mask pattern to form a second-color blue pattern B. did. (See FIG. 4B.) The dry etching was performed by reactive ion etching, and the etching conditions were the same as above.

Subsequently, thin films of a high light refractive index material and a low light refractive index material are alternately laminated on the dry etching mask pattern of chromium metal in the same manner as the green layer by a sputtering method. As a result, a red layer having a total film thickness of about 2.0 μm (strictly speaking, 1.94 μm) and forming a transparent multilayer thin film interference color filter pattern (for example, a red color pattern R of the third color) was formed. (FIG. 4
(See (c))

Subsequently, a dry etching mask pattern made of chromium metal on the first color green pattern G and the second color blue pattern B was formed by using a diammonium cerium nitrate solution (etchant). (A sound wave is also used) It is dissolved and removed to form a third color red pattern R on the transparent substrate, and three color blue patterns B and green are respectively formed in the pixel pattern areas Pc of each color display pixel pattern area CPc. A pattern G and a red pattern R were pattern-formed to obtain a color filter for a color liquid crystal projector by the multilayer thin film interference of the present invention. (See Fig. 4 (d))

If necessary, the pattern surface of the color filter may be overcoated with a transparent heat-resistant synthetic resin (epoxy resin, amide resin) or a surface polishing method by buffing. And then smoothed.

The heat resistance, weather resistance (moisture resistance, light resistance), definition, and transmittance of the color filters obtained in Examples 1 and 2 were tested under the following conditions and measured. No deterioration of the colors of the color patterns B, G, and R was found, and good results were obtained. Resolution Minimum pattern formable pattern; dot size Diameter 5 μm Transmittance Spectral transmittance in the peak regions of B, G, and R colors; 8
5% or more

[0099]

In the color filter for a color liquid crystal projector according to the first aspect of the present invention, a high refractive index material and a low refractive index material are alternately laminated in multiple layers on the transparent substrate 1 to form blue (B) and green ( G), since the spectral transmittance in the peak transmission region of red (R) is 85% or more, the color filter pattern L having heat resistance and weather resistance by the multi-layer thin film interference filter with a small light absorption rate is provided. When used as a color filter of a color liquid crystal projector, it acts as a color filter that is less deteriorated by heat generated from an intense light source of the projector and ultraviolet rays contained in the light source.

Further, in the method for manufacturing a color filter for a color liquid crystal projector according to the second aspect of the present invention, a color filter pattern formed by a multilayer thin film interference filter is formed by an ion assist method using a high photorefractive index material and a low photorefractive index of an inorganic compound. Thin films with materials are alternately laminated in multiple layers according to a combination of a predetermined film thickness and the number of layers, and spectrally colored, and it is patterned by a lift-off method or an etching method. An extremely high-definition color filter pattern layer L can be obtained.

Before the smoothing, the surface of the color filter pattern layer L of the obtained color filter is smoothed by a transparent synthetic resin by an overcoat method or a polishing method, if necessary. When a resist pattern or an etching mask pattern is peeled off (lift-off) at the time of pattern formation, or when a photoresist layer or an etching mask layer is formed by etching, the edge portions of the patterns B, G, and R of each color, or the resist pattern or mask Peeling residue and peeling residue on the edge of the pattern and rising of the edge (burrs, etc.)
If it occurs, it can be removed.

Further, after a transparent overcoat is applied to the surface of the color filter pattern layer L of the obtained color filter, the surface of the coat is smoothed by buffing or the like to obtain a color filter pattern layer. L
The surface of the color filter pattern layer L can be smoothed through the overcoat while the surface of the color filter is left as it is.

Thus, the color filter pattern layer L
Of the color filter of the present invention by removing the peeling residue, the peeling residue and the rising of the edge portion (burrs etc.) on the surface of the color filter and smoothing the surface of the color filter pattern layer L through the overcoat. A uniform cell gap for filling and encapsulating liquid crystal can be formed between the transparent substrate 1 of FIG. 1 and a counter electrode substrate (not shown) formed of a transparent substrate which is parallel to and opposed to the transparent substrate 1 with a predetermined fine distance. Heat resistance and weather resistance, which can obtain various display images,
It can serve as a color filter for a color liquid crystal projector having chemical resistance.

[0104]

The color filter for a color liquid crystal projector of the present invention has a spectral transmittance of an alternating multi-layered structure of a high light refractive index material and a low light refractive index material which does not depend on the dyeing method, the pigment dispersion method or the printing method. A color filter having good heat resistance, weather resistance and chemical resistance can be obtained, and it is effective as a color filter for a color liquid crystal projector using a strong light source.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a color filter for a color liquid crystal projector of the present invention.

2A to 2J are side sectional views showing a manufacturing process of an embodiment of a method for manufacturing a color filter for a color liquid crystal projector of the present invention.

3 (a) to 3 (j) are side sectional views showing manufacturing steps of another embodiment of the method for manufacturing a color filter for a color liquid crystal projector of the present invention.

4A to 4D are side sectional views showing manufacturing steps of another embodiment of the method for manufacturing a color filter for a color liquid crystal projector of the present invention.

FIG. 5 is a schematic side view of a color liquid crystal projector showing an example of use of a color filter for a color liquid crystal projector of the present invention.

[Explanation of symbols]

CPc ... color display pixel pattern Pc ... pixel pattern (pixel) L ... filter layers B ... blue pattern G ... green pattern R ... red pattern B ₀ ... blue layer G ₀ ... green layer R ₀ ... red layer 1 ... transparent substrate 2 ... Photoresist layer 2a ... Resist pattern (lift-off pattern) 3a ... Resist pattern 4a ... Resist pattern 5 ... Metal etching mask layer 5a ... Etching mask pattern 6 ... Photoresist layer 6a ... Resist pattern 7 ... Metal etching mask layer 7a ... Etching mask pattern 8 ... Transparent overcoat layer (and transparent electrode layer) 11 ... Illumination light source 11a ... Luminous flux 12 ... Optical lens system 21 ... Transparent substrate 21a ... Transparent electrode layer 22 ... Liquid crystal

Claims (4)

[Claims] 1. A light-absorbing material in which a high-refractive index material and a low-refractive index material are alternately laminated in multiple layers on a transparent substrate and each has a spectral transmittance of 85% or more in the red, green, and blue peak regions. A color filter for a color liquid crystal projector, which is provided with a color filter pattern formed by a multilayer thin film interference filter having a low rate. 2. A method for manufacturing a color filter for a color liquid crystal projector, wherein the color filter pattern of the multilayer thin film interference filter of the color filter for a color liquid crystal projector according to claim 1 is patterned by a lift-off method. . 3. A color filter for a color liquid crystal projector according to claim 1, wherein a color filter pattern of the multilayer thin film interference filter of the color filter for a color liquid crystal projector is patterned by a dry etching method. Method. 4. The color filter for a color liquid crystal projector according to claim 2, wherein the patterned color filter pattern surface is smoothed by using an overcoat method or a surface polishing method. Method.