JPS5983113A - Multicolor optical filter and its production - Google Patents

Abstract

PURPOSE:To provide an excellent spectral characteristic and durability by disposing many of >=2 fine parts having the selective scattering wavelength different from each other by a wavelength in a specific range and having different compsn. on a polymer composite body. CONSTITUTION:A soln. prepd. by dissolving a material that can form a cholesteric liquid crystal in a liquid compd. having a polymerizable unsatd. group is coated on a transparent substrate 1a and thereafter the temp. is controlled to form a layer 2 of a cholesteric liquid crystal. A transparent substrate 1b is formed thereon. UV light or the like 5 is irradiated thereon via a photomask 4 in order to cure a prescribed part. The one substrate 1b is removed and the uncured part 2b is removed, allowing the cured part 2a to remain. A monomer soln. of a cholesteric liquid crystal which can exhibit the selective scattering wavelength different from that in the part 2a and has a different compsn. is coated thereon and the temp. is controlled to cure partially the same by utilizing a photomask. The three cured liquid crystal parts, i.e., the fine parts 2a, 2c and 2d having the selective scattering wavelengths different from each other by 50- 300nm are formed by repeating the above-mentioned operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polychromatic optical filter such as a stripe filter and a mosaic filter, and a method for manufacturing the same.

Conventionally, color image pickup tubes, color charge-coupled devices (CCDs)
V interference filter type or dye filter used in color solid-state imaging devices such as charge couple denomination (chair) and charge injection device (CID). The Luther type is known. 61j@ interference 7
1 Luther-type color filters have superior spectral characteristics, but the manufacturing process is defective! ＋”t is complicated,
For example, in the case of color filters that have only one turn, the process is repeated for two or three colors, resulting in poor productivity and high costs. .

On the other hand, the latter dye 71 Luther type color 71 Luther uses a method of manufacturing by repeatedly dyeing a transparent film coated and dried on a transparent substrate 9 times using photoetching or the like. In some cases, the manufacturing of color filters with fine fj:, two-color or three-color or more patterns is complicated and has drawbacks, and furthermore, this evening 4
The spectral characteristics of a color filter are determined by the absorption of the dye, and the color of the dye is determined by the diffusion of the dye. The current situation is even worse. There were also problems with durability due to photobleaching of the dye.

Furthermore, there were few collar 71 knotters made in the previous year that were highly flexible and had the disadvantage that they could only be manufactured in a certain shape.

The inventors of the present invention have conducted intensive research to solve the above drawbacks.
We focused on the technology described in Japanese Patent Application Laid-open No. 139506/1983. The publication describes the technical ability to immobilize Cholesterol liquid crystals with polymers, and also describes the possibility of application to optical filters. However, the structure of a polychromatic optical filter using a fine pattern is not even suggested, and it has been found that the above-mentioned drawbacks cannot be solved in any way.

Therefore, the present inventors conducted further research and completed the present invention.

The object of the present invention is to have spectral characteristics that are ≦≦, and to have sufficient durability. ! An object of the present invention is to provide a multicolor optical filter that is easy to construct and a method for manufacturing the same.

The above-mentioned object of the present invention is to provide a polychromatic optical filter using a visible light scattering polymer composite '5, which is formed by immobilizing a cholesterol-staining liquid crystal having a helical pitch capable of selectively disturbing visible light. ) A polychromatic optical filter characterized by having a selective scattering wavelength of 50 to 3QQnmi and a large number of two or more minute parts each having a different power and composition disposed on a mer complex, and a substrate. To obtain a liquid crystal of 7T9J&L, the substance was dissolved in a liquid compound containing at least one polymerizable unsaturated group. After that, the unpolymerized portion is removed, and then a substance capable of forming a cholesteric liquid crystal with a different composition dissolved in a liquid compound having at least one polymerizable unsaturated group is applied, and one micro A111 portion is polymerized. By repeating this,
Polychromatic optics (polychromatic optics) characterized by forming two or more fine parts with different selective scattering wavelengths of 50 to 300 nm and different compositions) is achieved by a method of manufacturing 1 Luther.

Hereinafter, preferred embodiments of the method for manufacturing a polychromatic optical filter according to the present invention will be described with reference to fleshed-out drawings.

First, as shown in FIG. 1, a substance capable of forming a cholesteric liquid crystal on a transparent substrate 1a w'5r: a solution dissolved in a liquid compound having at least one polymerizable unsaturated group (
Hereinafter, this will be referred to as cholesteric liquid crystal monomer solution. ), the temperature is controlled to form a cholesteric liquid crystal layer 2 having a predetermined helical pitch, and a transparent substrate 1b is further formed thereon. In FIG. 1, 3 is a spacer, and two transparent substrates (for example, glass substrates) 1a and 1b are arranged at a predetermined interval. When layer 2 is sandwiched between the upper and lower layers, the cholesteric axis of the cholesteric liquid crystal is oriented perpendicularly to the glass surface, and in this state, a turn (hereinafter referred to as a fine turn) consisting of a fine portion is formed. It is preferable to write.

Next, as shown in FIG. 2, in order to harden a predetermined portion, a seven-layer mask 4 consisting of a light-shielding portion 4a and a light-transmitting portion 4b 75- is used.
UV rays etc. 5 are irradiated for a required period of time, for example, several minutes. In the figure, 2a indicates a hardened portion, and 2I) indicates an uncured portion.

Next, as shown in the third step, the transparent substrate 1b is removed and the unhardened portion 2b is removed, leaving the hardened portion 2a. Thereafter, as shown in FIG. 4, a cholesteric liquid crystal monomer solution having a different composition from the previous cholesteric liquid crystal monomer solution that can exhibit a selective scattering wavelength different from that of the portion 28 is applied, and the temperature is adjusted so as to exhibit a predetermined selective scattering wavelength. City I
J? iii L, use a photomask (not shown) to mark the sound separation.

By repeating this operation, a polychromatic optical 71 router according to the present invention having a predetermined fine pattern is manufactured (fifth
(see figure). In Fig. 5, 2a, 2c, and 2dil: three l1s whose selective scattering wavelengths differ by 50 to 300 nm.
i3 is a small part, and each is a hardened liquid crystal part.

The substrate used in the method for producing a polychromatic optical filter according to the present invention can be of any material as long as it has appropriate transparency for the electromagnetic waves used for polymerization during production. For example, glass, quartz, plastic, metal plates, etc. can be used, and the shape of the material may also be a plate, sheet, or film. Furthermore, the polychromatic optical filter may be formed directly on any element such as a solid-state image sensor.

The polychromatic optical filter manufactured by the manufacturing method of the present invention can be used even if separated from the above-mentioned one or two substrates used at the time of manufacturing, and the polychromatic optical filter manufactured by the conventional manufacturing method can be used. Unlike chromatic optical filters, it also has excellent performance in terms of rereadability.

The polychromatic optical filters according to the present invention may be used in combination of two or more filters having the same or different optical performance, as required.

Two or more fine parts (fine pattern) in the present invention
The line width of is determined depending on the intended use of the polychromatic optical filter. Generally, the thickness is 1 μm or more and 1100 II or less, and preferably 2 μm or more and 50 μm or less. This is because the object of the present invention is to provide a high-performance color filter for color separation with excellent spectral characteristics. Note that when used in color solid-state image sensors such as CCDs, the diameter is 3 μm.
Above, 20 μm or less is preferably used.

In the present invention, the selective scattering wavelength is determined depending on the purpose of use. Generally, a combination of three colors, 1 yellow, magenta and λ cyan, or a combination of three colors, blue, green, and red, is preferred. Furthermore, depending on the purpose, the absorption for one selectively scattered wavelength may be too sharp, and in this case, two or more fine nodules may be used in combination to realize one entire color. It may also be used to widen the range of absorption by varying the temperature during polymerization.

In the present invention, two or more fine patterns are formed as described above, and the selective scattering wavelengths of the colors constituting the patterns are different from each other by 50 to 300 nrn. For example, when forming a fine pattern using three colors of 1 yellow, magenta, and cyan, the selective scattering wavelength is 400 for each color.
~500nm.

500-600nm, 600-700nm, maximum 300nm
nm different. In this way, 1 yellow and cyan differ by a maximum of 300 nm, which is effective in preventing hue turbidity.

Examples of the substance capable of forming cholesterin liquid crystals used in the present invention include synthetic polypeptides and cellulose derivatives. As a synthetic polypeptide, poly(L-
glutamic acid), poly(L-aspartic acid), poly(
Polyamino acids such as D-glutamic acid) and poly(D-aspartic acid) and esters thereof are preferred. Particularly preferred polyglutamic acid esters and polyaspartic acid esters include methyl esters, ethyl esters, propyl esters, methyl esters, pentyl esters, hexyl esters, cyclohexyl esters, and benzyl esters of these acids. Cellulose derivatives include haloxypropyl cellulose, ffr9
Particularly preferred are cellulose and acetoxypropylcellulose. Furthermore, when a cholesteric liquid crystal can be formed by adding a xyl compound to a substance exhibiting nematic liquid crystal properties, it can also be used as a substance capable of forming the cholesteric liquid crystal discussed in the present invention. be.

Examples of the compound having at least one polymerizable unsaturated group used in the present invention include acrylic monomers such as methyl acrylate and ethyl acrylate, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, and cyclohexyl. Methacrylic monomers such as methacrylate, diethylene glycol diacrylate, neobentyl glycol diacrylate, 1,4-butanediol acrylate,
Polyfunctional acrylic monomers such as l,6-hexaneol diacrylate, tetraethyl 1/glycolone acrylate, polyethylene glycol-400 diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
1.3-Butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, polyethene glycol 200 dimethacrylate, polyfunctional methacrylic monomers such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol tetramethacrylate, styrene, substituted styrene Examples include styrenic monomers such as, acrylamide, substituted acrylamide, acrylonitrile, and the like.

The present invention utilizes a cholesteric liquid crystal composition in which a substance capable of forming a cholesteric liquid crystal is dissolved in a liquid compound having at least one polymerizable unsaturated group. Along with this, it greatly influences the helical pitch of the cholesteric liquid crystal after polymerization, that is, the selective scattering wavelength.

In order to form a polychromatic optical filter having fine patterns with different hues according to the present invention, this selective scattering wavelength must be nJ.
There is an upper limit to the mixing ratio (P) because there is a low temperature limit for the solubility of the substance that can form cholesteric liquid crystals in the monomer solution and a high temperature limit for polymerization of the monomer. There is a lower limit, usually 0.25 (
2:8) to 4 (8:2).

Polymerization in the production method of the present invention is carried out by using a photomask once a month with electron beams, ultraviolet rays, visible light, etc., or by scanning the electromagnetic waves, etc., to harden (fix) only predetermined portions. A method of forming a turn may also be used.

If necessary, a photosensitizer may be used for the upper face. The commonly used photosensitizer is −j=
Examples of benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, acetophenone, benzyl sulfur, butanedione, benzyl sulfur, (butyl ether) , carbazole, benzyl, thioxanthone, 2-chlorotheoton, fluorenone, etc. In this case, as a polymerization accelerator, tertiary amines such as dimethylamine ethanol, NN-dimethylaniline, triphenylphosph 17, etc. are used. May be used together.

Hereinafter, the present invention will be specifically explained with reference to examples. i? Needless to say, the invention is not limited to this embodiment.

(Example) Poly(r-butyl-glutamate) and triethylene glycol dimethacrylate 1 note 53. : A solution of 2 weights each of benzophenone and dimethylaminoethanol added to the solution mixed in step 47 was sandwiched between two pieces of quartz glass through a 100 μm polyester baser, and a photomask was used. (by irradiating it with a 500W ultra-high pressure mercury lamp [Ushio Inc.] at 20'C for 1 minute)
, 1 yellow fine pattern was formed.

Next, the unpolymerized portion was washed away with acetone, and a fine magenta pattern was formed in the same manner at 20C using a solution in which the mixing ratio of the previous solution was 42:58. Furthermore, after changing the photomask and raising the temperature to 30° C., a cyan fine pattern was formed in the same manner to produce a polychromatic optical filter of the present invention. The width of one fine stomb pattern of the polychromatic optical filter thus formed was about 30 μm.

According to the present invention, a multicolor optical filter having a fine pattern can be manufactured very easily in this way. At this time, the temperature range during manufacturing is narrow and control is easy. The spectral properties of the polychromatic optical filter thus produced were superior to those of conventional dye-type polychromatic optical filters, and it was also superior in terms of durability and flexibility.

[Brief explanation of the drawing]

1 to 5 are schematic sectional views showing a preferred embodiment of the fR manufacturing process of the polychromatic optical filter according to the present invention. In the figure, 1 is a transparent substrate, 2 is a cholesteric liquid crystal layer, and 3i
, i-spacer 14 is a photomask, 5 is an ultraviolet light, etc. Patent applicant Konishiroku Photo Industry Co., Ltd. Agent Patent attorney Nobuaki Sakaguchi (and one other person) Figure 1 Figure 2 Figure 3 Figure 41 Figure 5

Claims (2)

[Claims] (1) Visible light filter: In a polychromatic optical filter using a visible light scattering polymer composite formed by immobilizing a cholesteric liquid crystal having a helical pitch that can selectively disrupt rays, the polymer composite has a selective scattering wavelength. is 50-300
A polychromatic optical filter comprising a large number of two or more fine parts having different wavelengths and compositions. (2) After dissolving a substance capable of forming cholesteric liquid crystals on a substrate in a liquid compound having at least one polymerizable unsaturated group, polymerize one minute portion, and then unpolymerize , and then repeating the process of applying a solution of a substance capable of forming a cholesteric liquid crystal having a different composition in a liquid compound having at least one polymerizable unsaturated group, and polymerizing one fine part. A method for producing a polychromatic optical filter, characterized by forming two or more fine parts having different selective scattering wavelengths of 50 to 300 nm and different compositions.