JPS6132802A - Color separation filter - Google Patents

Abstract

PURPOSE:To obtain a color separation filter of high quality having further improved spectral characteristics such as light transmittance and color reproducibility and suitable for mass production by using an inorg. filter element as the material of a cyan color pattern and org. filter elements as the materials of color patterns other than the cyan color pattern. CONSTITUTION:An inorg. filter element made of a multilayered interference film is used as the material of a cyan color pattern, and org. filter elements each made of a transparent colored film are used as the materials of magenta color and yellow color patterns. A cyan color pattern 2 of a multilayered intereference film is first formed on a support 1, and the magenta color pattern 3 of a transparent colored film is formed. The patterns 2, 3 are in the form of parallel stripes. A striped yellow color pattern 4 is then formed so that it meets at right angles with the striped patterns 2, 3. The protective top layer 5 of a transparent resin is further formed as required so as to protect the filter elements on the support.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an optical filter, and more particularly to a color separation filter used in full-color liquid crystal display devices, image pickup tube type color cameras, solid-state color cameras, color facsimiles, etc. .

[Technical background of the invention and its problems] Color separation filters formed by forming a plurality of color patterns (for example, cyan, yellow, and magenta) in a stripe or mosaic shape generally use a multilayer interference film or the like. Inorganic filters and organic filters such as colored images have typically been used. Among these, inorganic filters are generally composed of inorganic substances, so they have the advantage of being excellent in heat resistance, light resistance, chemical resistance, and cleaning resistance, but they have little freedom in selecting spectral characteristics. The disadvantage is that the manufacturing process is complicated and the cost is high. On the other hand, organic filters, such as colored images obtained by coloring a transparent resin obtained by irradiating a transparent photosensitive material with an organic dye, have the advantage of having a greater degree of freedom in selecting spectral characteristics and having lower manufacturing costs. However, it had the disadvantage of being inferior in physical properties such as heat resistance, light resistance, and light transmittance.

For this reason, color separation filters that combine both a multilayer interference film and the above-mentioned colored image have been proposed.Such color separation filters have a large degree of freedom in selecting spectral characteristics and are inexpensive to manufacture. It has the advantage of not being very expensive.

However, in the above conventional color separation filter,
As yet, nothing has been obtained that fully satisfies both advantages in terms of manufacturing process and manufacturing cost, and improvement in spectral characteristics.

[Summary of the invention]

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a color separation filter that has further improved spectral characteristics such as light transmittance and color reproducibility, is of high quality, and is suitable for mass production. do.

1. That is, the color separation filter according to the present invention is a color separation filter in which a cyan color pattern and other color patterns and turns are formed on a support, in which the cyan color pattern is made of an inorganic filter element, and the cyan color pattern is made of an inorganic filter element. It is characterized in that the color patterns other than the above are made of organic filter elements.

[Detailed description of the invention]

Hereinafter, the present invention will be explained based on specific embodiments with reference to the accompanying drawings.

The inorganic filter element forming the cyan pattern of the color separation filter according to the present invention may be a filter element made of a known inorganic material, such as a filter element manufactured by forming an inorganic pigment into a vapor phase film by vacuum evaporation or sputtering, and then patterning the inorganic filter element. An inorganic pigment filter, a multilayer interference film filter made by alternately laminating a plurality of layers of low refractive index substances and high refractive index substances, etc. can be used.

On the other hand, for organic filter elements that form color patterns other than cyan, dichromate, chromate, or diazo compounds are added to hydrophilic resins such as polyvinyl alcohol, polyvinyl alcohol, polyvinylpyrrolidone, gelatin, casein, and griux. Organic dyed filters are formed by buttering and dyeing a photosensitive resin layer, and photosensitive colored filters are formed by applying and buttering a photosensitive colored material in which a pigment or dye is mixed with a transparent photosensitive resin. , thermal transfer filters made by thermally transferring sublimable dyes to resin films such as polyester or acrylic, and colorant vapor-phase films made by forming organic dyes or pigments into vapor-phase films using methods such as vacuum evaporation, followed by patterning. There are electrophoretic electrodeposition filters in which a pigment or dye is dispersed in a solvent and then electrodeposited by electrophoretic electrodeposition to form a colored layer.

Hereinafter, a preferred embodiment of the present invention will be explained by taking as an example a complementary color filter for an image pickup tube type color camera having cyan, yellow, and magenta color patterns. In this example, the cyan pattern is formed by an inorganic filter element made of a multilayer interference film, and the magenta and yellow patterns are formed by an organic filter element made of a transparent colored film. FIG. 1 is a sectional view showing the manufacturing process.

That is, first, a multilayer interference film constituting the cyan pattern 2 is formed on the support 1 (FIG. 1(a)).

As the support 1, a transparent substrate such as soda lime glass, borosilicate glass, alumina silicate glass, quartz glass, a synthetic quartz plate, an optical resin plate, a transparent resin filter, a cathode ray tube substrate, a solid-state image sensor, etc. can be used. It will be done.

The total number of high refractive index material layers and low refractive index material layers laminated on the support 1 is 6 or more, preferably 8 or more. If the number of combined layers is less than 6, the rise of the light transmittance characteristic at the boundary between the transmitting region and the reflective region will not be sharp, and the transmittance in the reflective region will become so small that it becomes undesirable. . Furthermore, as the number of laminated layers increases, the rise of the light transmittance characteristic at the boundary becomes sharper and the transmittance in the reflective region becomes smaller, but since the lamination process becomes complicated, from a practical point of view,
It is preferable that the thickness is up to a layer.

The laminated high refractive index material layer and low refractive index material layer are laminated so that the optical film thickness for light of a predetermined wavelength λ is 1/4λ. Note that the optical film thickness means a value of nd when the refractive index of the substance constituting the film is n and the film thickness is d.

In some cases, in order to reduce the phenomenon in which the transmittance changes as the wavelength changes in the transmission region (so-called ripple phenomenon), the optical film thicknesses of the high refractive index material layer 4 and the low refractive index material layer are set as follows. It is preferable to laminate them.

1> In a multi-line interference film type color separation filter formed by alternately laminating six or more high refractive index material layers and low refractive index material layers on a substrate, (a) a high refractive index layer laminated closest to the substrate; (b) At least two high refractive index material layers and a low refractive index material layer are sequentially and alternately laminated on the low refractive index first layer. (C) The optical film thickness of the material layer is 1/4λ, and (C) the optical film thickness of the high refractive index material layer on the side farthest from the substrate is set to 1/4λ, and the optical film thickness of the low refractive index material layer laminated thereon is Let the above optical film thickness be.

2) On the substrate, the optical film thickness for light with a predetermined wavelength λ is 1
/4λ high refractive index material layer and the optical film thickness is 1/4λ
In a multilayer interference film type color separation filter provided with a laminate formed by alternately laminating two or more low refractive index material layers, (a) an optical film between the substrate and the laminate; a high refractive index material layer having a thickness and a low refractive index material layer having an optical thickness of (b) a low refractive index material layer on the side of the laminate farthest from the substrate in this order; A high refractive index material layer having an optical thickness of 1/4λ, a low refractive index material layer having an optical thickness of , and a high refractive index material layer having an optical thickness of are provided in this order.

3) On the substrate, the optical film thickness for light with a predetermined wavelength λ is 1
/4λ high refractive index material layer and the optical film thickness is 1/4λ
In a multilayer interference film type color separation filter provided with a laminate formed by alternately laminating two or more low refractive index material layers, (a) an optical film between the substrate and the laminate; a high refractive index material layer having a thickness and a low refractive index material layer having an optical thickness of (b) a low refractive index material layer on the side of the laminate farthest from the substrate; A high refractive index material layer having an optical thickness of and a low refractive index material layer having an optical thickness of are provided in this order above.

As a high refractive index material, Ti02 (refractive index n=2.2)
, 5bzO3 (n=2.04), Ce02 (n=2.4
2), ZrO2 (n-2, 10), ZnS (n=2.
35) etc. are used. In addition, as low refractive index materials, SiO (n=1.46), CaF2 (n=1.23
>, MgF, (n=1.38), etc. are used. Among these, a combination of TiO2 as a high refractive index material and 5ho2 as a low refractive index material is preferable from the viewpoint of stress relaxation between layers when laminating multiple layers.

The high refractive index material layer and the low refractive index material layer are laminated by a vapor deposition method such as a vapor deposition method or a sputtering method. The optical film thickness of these material layers is controlled by a film thickness monitoring device such as a photoelectric film thickness meter.

After forming the cyan pattern 2 in this manner, a magenta pattern 3 made of a transparent colored film is formed (FIG. 1(b)).

This magenta color pattern was created by first placing a transparent photosensitive resin on a substrate, exposing it to light in a pattern, and then developing it.
This can be obtained by dyeing it magenta with a desired dye, or by providing a transparent photosensitive resin in which a magenta pigment is dispersed on a support, exposing it to light in a pattern, and then developing it.

In the specific example described here, the cyan pattern 2 and the magenta pattern 3 are formed in parallel stripes. In this way, pattern formation is performed with the surfaces of the cyan color pattern 2 and the magenta color pattern 3 leveled, so that there are no steps on the pattern surfaces, thereby eliminating problems caused by steps, such as straight light propagation. It is possible to solve the problem of the spectral properties being deteriorated due to a significant inhibition of the properties, thereby further improving the spectral properties.

After forming the cyan pattern 2 and the magenta pattern 3, a striped yellow pattern 4 is provided perpendicularly to these striped patterns (the first
Figure (C)). If necessary, before forming the yellow pattern 4, a transparent resist dyeing resin film made of a hydrophobic resin ( (not shown) may also be formed.

Further, if necessary, a protective layer 5 made of a transparent resin can be formed on the uppermost layer in order to protect the filter element on the support. .

FIG. 2 is a front view of the color separation filter created as described above, and FIG. 3 shows each part shown in FIG. 12 is a graph showing spectral transmission characteristics at C (combined part of magenta and yellow filter elements), and D (combined part of cyan and yellow filter elements).

As shown in FIG. 3, by forming the cyan pattern with an inorganic filter element, the transmittance characteristics of blue light in particular are improved, and the overall spectral characteristics and color reproducibility can be improved.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

1. A transparent support made of Pyrex glass is set in a part of the substrate holder of the vacuum evaporation equipment where the optical film thickness meter is placed.
After exhausting to lX1O-6 Torr, the substrate temperature was set to 35
The temperature was 0°C. Then, the “T’i” layered during vacuum deposition
In order to prevent 02 from being reduced to TiO or Ti, 02 gas was introduced to 2X10' TOrr, and then a Ti 02 beret sample (manufactured by Merck & Co., Ltd.) set in a predetermined hearth was sufficiently heated by electron beam heating. After preheating, open the shutter and deposit 1/2 TiO2 on the substrate.
It was deposited to an optical thickness of 4λ. This vapor deposition was carried out by setting the current value in the electron to 250 mA.
The iO2 film thickness is measured using a photoelectric film thickness meter.The monitor wavelength (λ) is set to 640 nm using a photoelectric film thickness meter. By monitoring the optical film thickness (n
d) was controlled to be 1/4λ.

Next, after stopping the introduction of 02, the 5i02 sample (manufactured by Optron) set in a designated hearth was heated with an electron beam, and after sufficiently preheating, the shutter was opened and the Si
Om was deposited on the TiO2 film to an optical thickness of 1/4λ. The optical thickness of the SiO2 film was controlled using a photoelectric film thickness meter in the same way as the TiO2 film. By repeating the same operation, a total of 14 layers of TiO films and 5in2 films were laminated, with 7 layers each alternately. Thereafter, the substrate was slowly cooled until the temperature reached 200° C. and then taken out into the atmosphere. Next, a positive resist 0FRP-800 (manufactured by Tokyo Ohka) was applied to a film thickness of 2 μm, and then electrophotographic development was performed using a mask of a predetermined shape.
Bost baking was performed under the conditions of 120°C and 3Q min to form a masking resist layer, and then CF4/3%
The multilayer interference membrane filter layer was dry etched by reactive ion etching using 02 gas.

Next, one layer of 0FPR-800 resist i was peeled off to form a cyan light transmitting cyan element.

Next, a water-soluble photosensitive film consisting of Hi-Pure Ii (manufactured by Miratan Norland Co., Ltd.) and ammonium dichromate was applied to a thickness of 1 μm, and then developed using an electric light using a mask having a predetermined shape. Then Q 1 acid Fast
A magenta color light transmitting filter element was formed by immersing it in a solution in which an acid dye of 3BL (manufactured by Mitsubishi Chemical Industries, Ltd.), acetic acid, and water were mixed in a weight ratio of 1:3:10. After resist dyeing treatment, a water-soluble photosensitive solution consisting of H+-pure gelatin and ammonium dichromate was applied to a 0.8 μm layer.
The film was coated to a thickness of 1:1, and then developed by lightning using a mask of a predetermined shape, and then coated with a solution containing Aminyl Yellow E-5GN (manufactured by Sumitomo Chemical) dye, acetic acid, and water in a weight ratio of 1:1:10. A yellow color light transmitting filter element was formed by dipping. Finally, a transparent organic resin was applied to produce a color separation filter of the present invention.

When the thus obtained filter was applied to a color separation filter for an image pickup tube, a color camera with excellent color reproducibility and sensitivity could be produced.

〔Effect of the invention〕

In a preferred embodiment of the color separation filter according to the present invention, the cyan color pattern is formed of a multilayer interference film, and the other color patterns are formed of transparent colored films, so that the spectral characteristics can be effectively improved. Moreover, since only one of the plurality of color patterns is formed of a multilayer interference film that requires a relatively complicated process, the manufacturing process can be simplified, which is advantageous in terms of mass productivity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the manufacturing process of a color separation filter according to a specific example of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a graph showing spectral transmission characteristics. 1...Support, 2...Cyan color pattern, 3...
Magenta color pattern, 4...Yellow pattern, 5...
protective layer. Applicant's agent Kiyoshi Inomata 1 Figure @ 1z

Claims (1)

[Claims] 1. In a color separation filter in which a cyan color pattern and other color patterns are formed on a support, the cyan color pattern is made of an inorganic filter element, and the color patterns other than cyan are made of an organic filter element. A color separation filter comprising: 2. The inorganic filter element is a multilayer interference film formed by alternately stacking a plurality of high refractive index materials and low refractive index materials,
The color separation filter according to claim 1, wherein the organic filter element is a transparent colored film.