JP4323893B2 - Manufacturing method of light amount adjusting member, light amount adjusting member, light amount adjusting device and photographing device - Google Patents

Description

  The present invention relates to a method for manufacturing a light amount adjusting member used in an optical apparatus such as a digital camera or a video camera, or an electrophotographic recording apparatus, a light amount adjusting member, a light amount adjusting device, and a photographing apparatus.

  An imaging (photographing) optical system used in an optical apparatus such as a camera generally includes a light amount adjusting device that adjusts the amount of incident light, that is, a so-called diaphragm device. In such a diaphragm device, a plurality of diaphragm blades form an opening of a predetermined area, and the amount of the light beam passing through the opening is adjusted by adjusting the opening diameter of the opening with an actuator. However, as the aperture diameter of the aperture is reduced, the influence of diffraction generated at the end of the aperture blade increases, and the imaging performance of the imaging optical system decreases. On the other hand, in order to avoid this drawback, an optical filter as a light quantity adjusting member is provided on a part of the diaphragm blades, and instead of reducing the aperture diameter, the amount of light beam passing through the aperture by the optical filter ( A technique for attenuating the light intensity) is known. An optical filter used for such a purpose is required to have few optical defects such as light scattering, refractive error, and spectral transmittance deviation.

  Conventionally, as this light amount adjusting member, a type in which a coloring material such as a pigment or dye that absorbs light is mixed and kneaded into a light-transmitting film-like material is generally used. However, the light amount adjusting member manufactured by this method is very expensive, and cannot sufficiently meet the cost reduction required for the expanding demand. Further, in the method of kneading a coloring material in this light-transmitting film-like material, a light amount adjusting member having an optical density distribution that changes continuously or stepwise (hereinafter referred to as “multi-density”) is provided. It is extremely difficult to manufacture.

  In addition, as another manufacturing method, a method of manufacturing a multi-concentration light amount adjusting member using a silver salt film is disclosed (for example, see Patent Document 1). In this case, silver contained in the filter is disclosed. A silver salt film is used in which the light beam passing through the filter is impaired by the reflection of the light beam on the particle surface or the diffraction of the light beam passing through the edge of the silver particle, thereby reducing the imaging performance of the optical system. A unique problem arises.

  There is also a proposal for a method for producing a multi-concentration light amount adjusting member by a vapor deposition method (see, for example, Patent Document 2). However, such a method is expensive and expensive, and in addition to the fact that the film thickness changes depending on the concentration, a difference in film thickness occurs between the high and low concentrations. There arises a problem that an optical path difference is generated and the resolving power is lowered. In this method, it is difficult to manufacture a product whose concentration distribution changes continuously, and even if manufactured, the concentration distribution changes stepwise.

  As another proposal, first, an organic dye that fades by light is kneaded into the film material, and the resulting film is partially irradiated with high energy light to decompose the organic dye in the irradiated portion. There is also a proposal for a method of manufacturing a light quantity adjusting member having a density distribution by using (see, for example, Patent Document 3). However, in this method, usable color materials are limited to those that fade by light, so it is very difficult to obtain a product having sufficient optical characteristics. Furthermore, it can be easily inferred from the manufacturing method that the resulting product will be very expensive.

  Furthermore, a filter as a light quantity adjusting member whose transmittance changes steplessly by forming a single-concentration film in halftone dots by a printing process such as vapor deposition or photoengraving, and changing the halftone dot pattern depending on the location. A method is disclosed (see, for example, Patent Document 4). However, the above method forms a film having a predetermined concentration by photolithography or vapor deposition. Regardless of which step is adopted, the apparatus becomes large and expensive, and the manufacturing cost of the optical filter increases. There is a problem of end.

JP-A-5-173004 JP-A-10-133254 Japanese Patent Laid-Open No. 10-96971 JP 2000-352736 A

  Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to provide a simple method for manufacturing a light amount adjusting member that has a low manufacturing cost and a high product yield. In addition to the above, an object of the present invention is to provide a method for producing a light amount adjusting member, in which a light amount adjusting member having a region (colored portion) having a concentration distribution in which the optical density changes continuously or stepwise can be easily obtained. Is to provide. Furthermore, an object of the present invention is to provide a light amount adjusting member that is manufactured by the above-described simple manufacturing method and has an inexpensive and excellent characteristic, a light amount adjusting device including the light amount adjusting member, and a photographing device. . It is another object of the present invention to provide a light quantity adjusting member with little image quality deterioration due to diffraction at the grain boundary of droplets that occurs during coloring in the colored portion of the light quantity adjusting member when the light quantity adjusting member is created by the liquid applying device.

  The above object is achieved by the present invention described below. That is, the present invention provides: [1] Light amount adjustment in which a colored portion composed of a specific optical density region containing at least a transparent resin and a color material and a transparent portion containing at least a transparent resin are formed on a transparent substrate. In the method for producing a member, a transparent material containing at least a transparent organic solvent and / or water using a first liquid application device on a transparent substrate on which a transparent resin layer having liquid absorbability is provided. After the liquid is applied to swell the transparent resin layer, before the transparent resin layer is dried, the transparent resin layer is colored using the second liquid application device, or the colored liquid and the transparent liquid And a process for forming a colored portion consisting of at least a specific optical density region.

  Moreover, the following [2]-[6] is mentioned as a preferable form of the manufacturing method of the light quantity adjustment member concerning the above-mentioned this invention. [2] The first liquid application device is a micro droplet ejection device that ejects droplets from a micro nozzle array, and the width of the nozzle array is equal to or larger than the width of the light amount adjusting member to be manufactured. Manufacture of the light amount adjusting member according to [1], wherein the transparent liquid is applied to the entire surface of the transparent base material without a gap by performing one scan at a width equal to or larger than the width of the light amount adjusting member to be manufactured using a droplet discharge device. Method. [3] The second liquid application device is a micro droplet ejection device that ejects droplets from a minute nozzle row, and a colored liquid or a colored liquid is applied to the transparent resin layer swollen from the minute nozzle row. The method for producing a light amount adjusting member according to the above [1] or [2], wherein the liquid and the transparent liquid are discharged and applied, and a colored portion including at least a specific optical density region is formed on the transparent substrate. [4] The method for producing a light amount adjusting member according to any one of [1] to [3], further including a step of providing a transparent layer on at least the surface of the colored portion after the step of forming the colored portion. [5] The method for producing a light amount adjusting member according to any one of [1] to [4], wherein the color material is a dye, a pigment, or a mixture thereof. [6] The method for manufacturing a light amount adjusting member according to any one of [1] to [5], further including a step of providing an antireflection film on both surfaces of the light amount adjusting member after the step of forming the colored portion. [7] The above-mentioned [1] to [1], wherein the specific optical density region has a density distribution continuously or stepwise formed by partially changing the type and / or amount of the color material. [6] The method for producing a light quantity adjusting member according to any one of [6].

  Another embodiment of the present invention is [8] a light amount adjusting member manufactured by the method for manufacturing a light amount adjusting member according to any one of [1] to [7]. Another embodiment of the present invention is [9] a light amount adjusting device comprising the light amount adjusting member described in [8] above. In another embodiment of the present invention, [10] a light amount adjusting device, a photographing optical system for forming a subject image, an imaging means for photoelectrically converting the subject image, and a photoelectrically converted signal are recorded. An imaging apparatus including a recording unit, wherein the light amount adjusting apparatus described in [9] is arranged in the imaging optical system.

  As described above, according to the present invention, since the liquid absorbing layer is swollen with the transparent liquid before the coloring step, when the colored droplets land on the liquid absorbing layer in the coloring step, Even if a coloring liquid is further applied in this state, swelling of the liquid absorption layer is difficult to proceed, so that the surface unevenness in the coloring process does not easily increase, and the grain boundary between dots in the colored portion As a result, it is possible to obtain a light amount adjusting member having optical characteristics with little decrease in resolving power. In addition, according to the present invention, since the light amount adjusting member can be manufactured by the liquid ejection device, a method for manufacturing the light amount adjusting member that can manufacture the light amount adjusting member at a low cost with a high yield is provided.

  In particular, according to the present invention, it is possible to easily and inexpensively manufacture a light amount adjusting member having a concentration distribution in which the optical density changes continuously or stepwise, which is extremely difficult with other manufacturing methods. A method for manufacturing a possible light amount adjusting member is provided. Furthermore, according to the present invention, the light amount adjusting member, the light amount adjusting device, and the photographing device that are excellent in optical characteristics are provided at low cost by the above method.

  Next, the present invention will be described in more detail with reference to preferred embodiments. As a result of intensive studies to solve the above-described problems of the prior art, the present inventors, when manufacturing a light amount adjusting member, if a colored portion consisting of a specific optical density region is formed using a liquid application device, Although it can be manufactured very simply and with a good yield and at a low cost, a good light amount adjusting member can be obtained by using a transparent substrate having a transparent resin layer having liquid absorbability on the surface. In this case, if the transparent resin layer is swollen with a transparent liquid mainly composed of water or the like before the coloring step for applying the coloring liquid, the resolution is less reduced as compared with the case where the treatment is not performed. The inventors have found that a light amount adjusting member having optical characteristics can be obtained, and have reached the present invention. The present inventors consider the reason why such an effect is obtained as described above. As described above, if a transparent liquid is applied to the transparent resin layer having liquid absorbency before the coloring step to swell the liquid, the colored liquid droplets land on the transparent substrate in the coloring step. Sometimes, since the swelling of the transparent resin layer has already progressed, the swelling of the transparent resin layer is difficult to proceed even if a coloring liquid is further applied, and the surface unevenness in the coloring process is unlikely to increase. Since it is difficult for diffraction to occur at the grain boundaries between the dots in the colored portion, it is presumed that a light amount adjusting member having optical characteristics with little reduction in resolving power was obtained.

  The light amount adjusting member obtained by the manufacturing method according to the present invention is formed on a transparent substrate by a colored portion composed of a specific optical density region containing at least a transparent resin and a color material, and a transparent portion containing at least the transparent resin. First, as a transparent substrate, a transparent substrate having a liquid-absorbing transparent resin layer (hereinafter referred to as a liquid absorbing layer) is used. After the transparent resin layer is swelled by applying a transparent liquid containing at least a transparent organic solvent and / or water using one liquid application device, the transparent resin layer is dried before the transparent resin layer is dried. The method includes a step of forming a colored portion including at least a specific optical density region by applying a colored liquid or a colored liquid and a transparent liquid to the layer using a second liquid applying apparatus. Hereinafter, materials used in the present invention will be described.

  First, the transparent substrate that can be used in the present invention is not particularly limited as long as it has necessary characteristics such as mechanical strength and optical characteristics as a light amount adjusting member. For example, a transparent film made of polyethylene terephthalate, diacetate, triacetate, cellophane, celluloid, polycarbonate, polyimide, polyvinyl chloride, polyvinylidene chloride, polyacrylate, polyethylene, polypropylene and the like can be mentioned. In addition, transparent glass can be used for the base material as long as it satisfies the above-mentioned necessary characteristics. Furthermore, the transparent base material appropriately selected from the materials listed above is transparent by subjecting its surface to various treatments such as plasma treatment, UV treatment, UV ozone treatment, corona treatment, and silane coupling treatment. The surface of the substrate may be modified. These treatments may help to improve adhesion when a liquid absorbing layer is formed on a transparent substrate as described above to form a liquid absorbing layer.

  In the manufacturing method of the light quantity adjustment member concerning this invention, the transparent resin layer (liquid absorption layer) which has liquid absorptivity is formed on the surface of the transparent base material mentioned above is used. As a material for receiving a liquid such as a colored liquid used for the liquid absorbing layer formed on the transparent substrate, the material that absorbs the colored liquid or the like and can receive and fix at least the coloring material in the colored liquid in the layer. There is no particular limitation as long as it is present, and water-soluble resins and water-dispersible resins as listed below can be used.

  Examples of the water-soluble resin include polyvinyl alcohol and modified products of polyvinyl alcohol such as anion-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, and acetal-modified polyvinyl alcohol; water-based polyurethane; polyvinyl pyrrolidone; and vinyl pyrrolidone / vinyl acetate copolymer, Modification of polyvinylpyrrolidone such as vinylpyrrolidone and dimethylaminoethyl / methacrylic acid copolymer, quaternized vinylpyrrolidone / dimethylaminoethyl / methacrylic acid copolymer, vinylpyrrolidone and methacrylamidepropyltrimethylammonium chloride copolymer Cellulose-based water-soluble resins such as carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose; and cationized hydroxyethyl cell Modified products of cellulose such as cellulose; Synthetic resins such as polyester, polyacrylic acid (ester), melamine resin, or modified products thereof, and graft copolymers containing at least polyester and polyurethane; albumin, gelatin, casein And natural resins such as starch, cationized starch, gum arabic, and sodium alginate.

  Examples of the water dispersible resin include polyvinyl acetate, ethylene-vinyl acetate copolymer, polystyrene, styrene- (meth) acrylate copolymer, (meth) acrylate polymer, vinyl acetate- (Meth) acrylic acid (ester) copolymer, poly (meth) acrylamide, (meth) acrylamide copolymer, styrene-isoprene copolymer, styrene-butadiene copolymer, styrene-propylene copolymer, polyvinyl ether , Silicone-acrylic copolymers and the like can be listed, but of course the present invention is not limited to these.

  In addition, by using a coating liquid containing alumina hydrate, amorphous silica or the like in various resins as mentioned above, pores (alumina hydrate or amorphous It is also possible to form a gap absorption type liquid absorption layer that creates a gap between silica fine particles and absorbs a liquid such as a colored liquid in the pores. In addition, various surfactants and crosslinks are included in the material for forming the liquid absorption layer in order to improve the coating properties of the liquid absorption layer, the absorption performance of the liquid such as a colored liquid, and the improvement of mechanical properties. Agents, dye fixing agents (waterproofing agents), antifoaming agents, antioxidants, viscosity adjusting agents, pH adjusting agents, fungicides, plasticizers, and the like may be included.

  As a method of forming the liquid absorption layer on the transparent substrate using the above-described material, for example, the following is performed. First, materials such as water-soluble resin and water-dispersible resin that can accept a liquid such as the above-mentioned coloring liquid, water or alcohol, polyhydric alcohols, or other additives, together with other additives that are added as necessary. A coating liquid is prepared by dissolving or dispersing in a liquid medium selected from an appropriate organic solvent or the like. Next, the obtained coating liquid is, for example, roll coater method, blade coater method, air knife coater method, gate roll coater method, bar coater method, size press method, spray coating method, gravure coater method, curtain coater method, spin Coating is performed on the surface of the transparent substrate by a coating method such as a coating method. Thereafter, for example, the liquid absorption layer is formed by performing drying using a hot air drying furnace, a thermal drum, a hot plate, or the like.

  In the method for producing a light amount adjusting member according to the present invention, at least a transparent organic solvent and / or water is used on the liquid absorbing layer provided on the transparent substrate as described above, using the first liquid application device. After the liquid absorbing layer is applied to swell the liquid absorbing layer, and before the liquid absorbing layer is dried, the liquid absorbing layer is colored with a coloring liquid or a coloring liquid using a second liquid applying device. A colored liquid comprising at least a specific optical density region is formed by applying a transparent liquid. A transparent liquid for swelling the liquid absorbing layer used in this case, a colored liquid for forming a colored portion composed of an optical density region, and a transparent liquid used together with the colored liquid will be described.

  The coloring liquid for forming a colored part in the liquid absorption layer provided on the transparent substrate is composed of at least a coloring material and a liquid medium in which the coloring material is dissolved or dispersed. Moreover, the transparent liquid used when swelling the liquid absorption layer provided on the transparent base material used by this invention contains what contains at least a transparent organic solvent and / or water. Furthermore, the transparent liquid used with a coloring liquid can use the thing containing a transparent organic solvent and / or water similarly to the above. The transparent liquid used when the liquid absorbing layer on the transparent substrate is swollen and the transparent liquid used together with the coloring liquid may be the same, but of course, the type and content of the organic solvent used Different amounts may be used.

  As the liquid medium constituting the colored liquid and the transparent liquid, an aqueous liquid medium containing water and a water-soluble organic solvent is generally used. Moreover, the transparent liquid used by this invention uses the thing containing an organic solvent and / or water. The organic solvent contained in these and the organic solvent contained in the coloring liquid may be the same or different types. As the organic solvent used in the present invention, a solvent with little coloring in the visible region is desirable.

  As the organic solvent used in the present invention, it is particularly preferable to use organic solvents miscible with water. As the organic solvent that can be used in the present invention, those having high moisture retention and excellent hydrophilicity, those having good wettability to organic and hydrophobic surfaces, solvents having evaporative drying properties, moderate A low-viscosity solvent having high wettability.

  Examples of organic solvents that can be used in the present invention include ethylene glycol, diethylene glycol, triethylene glycol, tripropylene glycol, glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol, 1, 2,5-pentanetriol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, dimethyl sulfoxide, diacetone alcohol, glycerin monoallyl ether, propylene glycol, butylene glycol, polyethylene glycol 300, Thiodiglycol, N-methyl-2-pyrrolidone, 2-pyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, sulfolane, trimethylolpropane, trimethylolethane, neopentylglycol , Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoallyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene Glycol monomethyl ether, dipropylene glycol monomethyl ether, β-dihydroxyethyl urea, urea, acetonyl acetone, pentaerythritol, 1,4-cyclohexanediol, hexylene glycol, ethylene glycol monopropyl ether, ethylene glycol mono-n-butyl ether, Ethylene glycol monoisobutyl ether Ethylene glycol monophenyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, propylene glycol mono Butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, glycerin monoacetate, glycerin diacetate Glycerin triacetate, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, cyclohexanol, 1,2-cyclohexanediol, 3-methyl-1,5-pentanediol, 3-hexene-2,5-diol, 2, Examples include 3-butanediol, 1,5-pentanediol, 2,4-pentanediol, 2,5-hexanediol, 1-methoxy-2-propanol, furfuryl alcohol, and tetrahydrofurfuryl alcohol. The total amount of the organic solvent as described above is preferably used in the range of 5 to 40% by mass with respect to the entire coloring liquid and transparent liquid.

  The colored liquid or the transparent liquid made of the material as described above used in the present invention is not particularly limited as long as it can be discharged by a micro droplet discharge device. In addition, as the colored liquid or transparent liquid, both water-based and oil-based liquids can be used. From the viewpoint of ejection reliability from the fine droplet discharge device, it is possible to use water-based colored liquid and transparent liquid. preferable. Low boiling alcohols may also be added for the purpose of adjusting the viscosity.

  The coloring material used in the present invention may be any coloring material as long as it can form a colored portion that is a region having a specific optical density when applied to a transparent substrate. Therefore, the color material referred to in the present invention refers to a material that controls the transmittance of light in a predetermined wavelength band including visible light, ultraviolet light, and infrared light. When an ND filter (Neutral Density Filter) is manufactured by the method for manufacturing a light amount adjusting member according to the present invention, for example, a filter that provides a specific transmission characteristic that is uniform over the entire visible light band can be used. The invention is not limited to this. For example, when used in a light amount adjusting device for an infrared camera, a material that transmits only a specific wavelength in the infrared region is used, and this is also included in the color material referred to in the present invention. Further, light absorption when controlling the amount of transmitted light is included in the color material as referred to in the present invention, such as light absorption occurring inside the material or material surface. Specifically, various dyes and pigments can be used. As the pigment, organic pigments and inorganic pigments (complexes of various metals, various metal oxides, metal nitrides, etc., composites with organic fine particles, etc.) can be used. Further, various dyes as described above, organic pigments, inorganic pigments and the like can be appropriately mixed and used.

  In addition to the above-described components, the coloring liquid and transparent liquid used in the present invention may further include various surfactants and dye fixing agents in order to obtain coloring liquids and transparent liquids having desired physical properties as required. (Waterproofing agent), antifoaming agent, antioxidant, viscosity adjusting agent, pH adjusting agent, plasticizer, preservative and the like can be added. In addition, the colored liquid used in the present invention can be appropriately used as long as it satisfies the optical characteristics desired in the present invention, in which fine particles such as alumina hydrate, silica, and calcium carbonate are mixed and dispersed. .

  In the present invention, as the base material, a transparent base material having a liquid absorbability (liquid absorption layer) provided on the transparent base material as listed above is used. After the transparent liquid is discharged using the first liquid applicator to swell the transparent resin layer, before the transparent resin layer is dried, the second liquid applicator is used to add the coloring liquid or coloring. A liquid and a transparent liquid are applied to form a colored portion or a transparent portion, which is a region having a specific optical density. At this time, in particular, the first liquid applying device is a micro droplet ejection device that ejects droplets from a micro nozzle row, and the width of the nozzle row is greater than or equal to the width of the light amount adjusting member to be manufactured, It is preferable to apply the transparent liquid to the entire surface of the transparent resin layer of the transparent base material without any gaps by using the microdroplet discharge device and scanning the transparent liquid one scan at a width equal to or larger than the width of the light amount adjusting member to be manufactured. As the second liquid applying device, it is preferable to use a micro droplet ejection device that ejects droplets from a micro nozzle array.

  Further, when a transparent resin layer (liquid absorption layer) having liquid absorbency is provided on a transparent substrate, a coating liquid containing a transparent resin for forming the liquid absorption layer using a microdroplet discharge device In this case, a liquid absorption layer is formed by applying a film by discharging it onto a transparent substrate in one pass using a head having a nozzle row that is equal to or larger than the width of the light quantity adjusting member to be formed. It is also a preferable embodiment of the present invention that a coloring process for applying a colored liquid or a colored liquid and a transparent liquid is performed before the liquid is completely dried. According to this form, simplification of the process can be achieved.

  As a method of a micro droplet discharge device that discharges a colored liquid or a transparent liquid that can be used in the above-described process and applies the liquid onto a transparent substrate, a bubble jet using an electrothermal transducer as an energy generating element (registered) (Trademark) type, or a piezo jet type using a piezoelectric element. In the present invention, any micro-droplet ejection device having these functions can be used. Although there are commercially available printers as the micro droplet discharge device as the printing device, any of these can be used in the present invention. Of course, the present invention is not limited to this, and a printing apparatus specially manufactured for the present invention may be used.

  The colored portion and / or the transparent portion formed on the transparent substrate by the production method according to the present invention can have various patterns depending on the purpose so as to be a region having a specific optical density. For example, an area having a uniform optical density and a transparent area may be used, or an optical density may be changed continuously or stepwise to form an area having a density gradient and a transparent area. The region in which the optical density is changed continuously or stepwise is obtained by mounting a plurality of inks having different colorant concentrations stepwise as the coloring liquid to be mounted on the printing apparatus as mentioned above, or The ink can be easily formed by using these inks and appropriately controlling the ink discharge amount.

  According to the method of the present invention, in particular, the transparent region can be formed without applying the coloring liquid, but according to the study by the present inventors, it is better to apply the transparent liquid together with the coloring liquid to form the transparent portion. desirable. In particular, according to such a method for manufacturing a light amount adjusting member according to the present invention, a light amount adjusting member having a colored portion having a density gradient in which the optical density changes continuously or stepwise is easily produced. be able to. Furthermore, since the method according to the present invention has a high degree of freedom in the optical density gradient pattern that can be formed, there is also an advantage that optical optimization can be easily performed for the characteristics desired for the light amount adjusting member.

  In the method for producing a light amount adjusting member according to the present invention, a hot air drying furnace, a thermal drum, a hot plate, or the like is used as necessary after applying a colored liquid or a transparent liquid on a transparent substrate as described above. The drying process may be performed. In particular, when a crosslinking agent is mixed in the coloring material or transparent portion forming material, these materials are applied on the transparent substrate, and then heated or irradiated with light to form the colored portion or transparent portion. It is preferable to perform a curing treatment of the coating film.

  According to the method of the present invention having the above-described configuration, the colored part is formed as a colored resin film on the transparent substrate, and the transparent part is formed as a transparent resin film on the transparent substrate. Furthermore, it is preferable to provide a transparent flattening layer on these coatings as necessary. That is, the colored part and the transparent part formed above are formed by discharging and applying a colored liquid or a transparent liquid to the liquid absorbing layer provided on the transparent substrate. Swelling may occur and the surface may be uneven. On the other hand, even if the surface is uneven even partially, the optical characteristics are not uniform, and it may be difficult to form a colored portion or a transparent portion having a specific optical density region. Therefore, it is effective to flatten the surface after forming the colored portion and the transparent portion.

  In this case, as the material used for forming the transparent flattening layer, any of the materials enumerated above, which can absorb a liquid such as a colored liquid, which is a constituent material of the liquid absorbing layer provided on the transparent substrate, is used. However, there is no particular limitation as long as it satisfies the required performance such as adhesion to the resin forming the colored layer, mechanical strength, and optical characteristics. Specifically, for example, an acrylic or epoxy-based thermosetting resin or photocurable resin can be suitably used. As a method for forming the transparent flattening layer, after applying a coating liquid composed of these resin-forming materials onto a transparent base material on which a colored portion is formed to form a coating film, A method of baking with an oven, a hot plate or the like to form a cured film, or a method of irradiating the substrate with an electron beam or ultraviolet rays to form a cured film can be used. The thickness of the flattening layer formed at this time is appropriately about 0.1 to 30 μm, for example, although it depends on the required performance.

  Furthermore, in the method for producing a light amount adjusting member according to the present invention, antireflection treatments on the front and back surfaces can be suitably used as means for eliminating surface reflection that may occur on the surface of the colored resin film that is the colored portion. This antireflection film is required to have excellent antireflection characteristics in the visible light band and excellent moisture and harmful gas blocking characteristics. In order to satisfy this requirement, it is preferable to use a vapor-deposited multilayer film of an inorganic material. In the formation of the antireflection film, for example, the use of the antireflection film described in JP-A-6-273601 by the applicant of the present application prevents stray light from being generated due to the reflection of the surface of the filter, while also preventing moisture and harmful effects. The gas can be prevented from entering the coloring material, and the deterioration of the coloring material can be prevented.

  Next, optical characteristics of the light amount adjusting member obtained by the method for manufacturing the light amount adjusting member according to the present invention described above will be described. First, when judging the quality of the light amount adjusting member, (1) when used alone, the color material is deteriorated in optical performance caused by scattering or refracting the light beam, and (2) used in an aperture device or the like. It is necessary to evaluate the above three items of the anti-diffraction effect in the case, and (3) spectral transmittance.

  Here, in (3), the characteristics of the filter can be freely adjusted according to the type of the color material to be used, and can be easily measured using a commercially available spectral transmittance meter. On the other hand, the evaluation item (2) is suitable for evaluating the optical characteristics of the light quantity adjusting member alone because factors such as the shape of the aperture blade and the aperture value (F number) at the time of evaluation greatly affect the evaluation result. Absent. The method (1) is suitable for evaluating the optical characteristics of the light quantity adjusting member alone. Therefore, in each example described later, the measurement results of the optical characteristic evaluation method of the light quantity adjusting member alone and the uniform concentration light quantity adjusting member prepared by the manufacturing method of each example are described.

  The optical superiority when the optical density of the light amount adjusting member is changed stepwise or continuously is described, for example, in JP-A-6-95208 and JP-A-11-15042. On the other hand, according to the study by the present inventors, the light amount adjusting member whose optical density manufactured by the manufacturing method according to the present invention changes stepwise or continuously is simple when applied to an aperture device. In spite of being obtained by a simple manufacturing method, it has been found that an effect equivalent to that obtained by the above-described conventionally known technique can be obtained.

  Hereinafter, the light quantity adjusting device using the light quantity adjusting member obtained by the manufacturing method according to the present invention will be described. In addition, this invention is not limited to the structure described below. Fig.1 (a) is a figure which shows the aperture blade which comprised the light quantity adjustment member concerning this invention. Here, a diaphragm device used in a video camera or the like will be described as an example of the light amount adjusting device. FIG. 1B is a cross-sectional view taken along line A-A ′ in FIG. Reference numeral 101 in the drawing denotes the entire aperture blade, and a colored portion 101P (gradation portion in FIG. 1) made of a specific optical density region formed as described above, and a transparent portion 101R (gradation adjacent portion) that transmits light. ) And a light blocking member 101Q that blocks light. In FIGS. 1 and 2, the light blocking member 101Q is not colored in order to clarify the boundary with the light amount adjusting member 101P. However, since it is originally a member that blocks light, it is black or the like. Is formed. In the illustrated example, a transparent flattening layer 113 is provided on the colored portion, and an antireflection film 114 is provided on each outermost surface.

  FIG. 2 is a diagram of a light amount adjusting device using the diaphragm blades of FIG. In FIG. 2, reference numeral 100 denotes the entire light amount adjusting device. 101 is the first diaphragm blade shown in FIG. 1, and 102 is the second diaphragm blade. The second diaphragm blade 102 is manufactured by the same method as the first diaphragm blade, and includes a colored portion 102P, a transparent portion 102R that transmits light, and a light blocking member 102Q. Reference numeral 103 denotes a diaphragm blade driving lever that is fitted in a shaft of a motor (not shown) in a hole 103a and is rotated around the hole 103a. The first diaphragm blade 101 and the second diaphragm blade 102 are engaged with the projecting pins 103b and 103c at both ends of the diaphragm blade driving lever 103 in the respective groove holes 101a and 102a. Reference numeral 105 denotes a guide pin of a ground plate (not shown) that is slidably engaged with the grooves 101b and 102b at the side edges of the first and second diaphragm blades 101 and 102, and 106 denotes the ground plate. The optical path holes 101c and 102c penetrating through the apertures are the aperture opening edges of the first and second aperture blades 101 and 102, respectively.

  FIG. 2 shows a state when the aperture is fully open. When the diaphragm is gradually narrowed from the fully opened state, the optical path hole 106 which is the aperture of the diaphragm is covered with the colored portions 101P and 102P of the first and second diaphragm blades, and thus passes through the optical path hole 106. The light transmittance is gradually lowered.

  FIG. 3 is a schematic layout diagram when the light amount adjusting device shown in FIG. 2 is arranged in an optical device. In the present embodiment, an optical apparatus will be described by taking as an example a video camera that photoelectrically converts a moving image or a still image into an electric signal by an imaging means and records this as digital data. An imaging optical system 400 includes a plurality of lens groups, and includes a first lens group 401, a second lens group 402, a third lens group 403, and the diaphragm device 100 shown in FIG. Reference numeral 401 denotes a fixed front lens group, 402 denotes a variator lens group, and 403 denotes a focusing lens group. Reference numeral 404 denotes an optical low-pass filter. An imaging unit 411 is disposed at the focal position (scheduled imaging plane) of the photographing optical system 400. This includes a photoelectric conversion unit such as a two-dimensional CCD comprising a plurality of photoelectric conversion units that convert irradiated light energy into charges, a charge storage unit that stores the charges, and a charge transfer unit that transfers the charges and sends them to the outside. Conversion means are used.

  Reference numeral 421 denotes a display such as a liquid crystal display, which displays the subject image acquired by the imaging unit 411 and the operation status of the optical device. Reference numeral 422 denotes a group of operation switches including a zoom switch, a shooting preparation switch, a shooting start switch, and a shooting condition switch for setting a shutter speed. Reference numeral 423 denotes an actuator that performs focus driving, adjusts the focus state of the photographing optical system 400, and drives other members.

  The CPU 431 calculates whether the captured average density is equal to the numerical value corresponding to the appropriate exposure stored in itself, and if there is a difference, the absolute sign of the difference is calculated. The diaphragm aperture is changed according to the absolute value, or the charge accumulation time in the image pickup means 411 is changed. When moving the diaphragm, the diaphragm blade driving lever 103 is rotated about the rotation center 103a by the diaphragm driving circuit 432, so that the diaphragm blades 101 and 102 slide up and down. As a result, the size of the optical path hole 106 that is the opening changes. In this way, the optimum exposure can be obtained by changing the aperture area or the charge accumulation time.

  The image of the subject imaged on the image pickup means 411 at the optimum exposure is converted into an electric signal as a charge amount for each pixel according to the intensity of the brightness, amplified by the amplifier circuit 441, and then the camera signal. The processing circuit 442 performs processing such as predetermined γ correction. Note that this processing may be performed by digital signal processing after A / D conversion. The video signal thus created is recorded by the recorder 443.

  Next, the present invention will be specifically described with reference to examples and comparative examples. In the text, “parts” and “%” are based on mass unless otherwise specified.

<Example 1>
As a transparent substrate, a 100 μm thick polyethylene terephthalate film is coated with polyvinyl alcohol (PVA) at a thickness of 5 μm to form a liquid absorbent transparent resin layer (PVA layer). It was. And using Canon BJ F900, which is a bubble jet (registered trademark) type ink jet printer using an electrothermal transducer as an energy generating element, a coloring liquid having the following composition and Two kinds of transparent liquids were filled, and using these, a colored part and a transparent part were formed on the transparent base material provided with the PVA layer by the following method. In this example, the same liquid supply device and the second liquid application device were used. First, in the first step, only the transparent liquid was discharged on the entire surface of the PVA layer of the transparent substrate obtained above in one pass to swell the transparent resin layer. Next, the pattern of the light quantity adjusting member was created using a transparent liquid and a colored liquid. At this time, the colored part formed by applying the coloring liquid by the printer gives a density gradient in which the optical density of the colored part continuously changes. In this embodiment, a transparent liquid is used so that a part thereof becomes a transparent region.

(Composition of the coloring liquid used in Example 1)
・ C. I. Direct Black 168 1.5 parts C.I. I. Direct Yellow 86 0.45 part C.I. I. Direct Yellow 132 0.15 part C.I. I. Direct Blue 199 0.3 part C.I. I. Acid Red 315 0.9 part ・ Ethylene glycol 10 parts ・ Ethylene glycol mono-n-butyl ether
10 parts / water 76.7 parts

(Composition of the transparent liquid used in Example 1)
・ 10 parts of ethylene glycol ・ Ethylene glycol mono-n-butyl ether
10 parts / Ion exchange water 80 parts

  Next, a transparent flattening layer was further provided by the following procedure on the surface of the colored resin layer, which is a colored portion formed as described above, and the transparent resin layer, which is a transparent portion. First, a coating solution containing a styrene-butadiene copolymer (TR2000C manufactured by JSR Corporation) was prepared using a toluene / methyl ethyl ketone solution so that the copolymer was 10 parts in terms of solid content. This coating solution was applied onto the colored resin layer and the transparent resin layer using a wire bar, and then dried in a hot air drying oven at 100 ° C. for 5 minutes. The thickness of the transparent flattening layer thus prepared was 10 μm. Finally, an antireflection film described in JP-A-6-273601 was formed thereon to produce a light amount adjusting member as shown in FIG.

<Comparative Example 1>
In Example 1, the same configuration as in Example 1 was applied in the same manner as in Example 1 except that the transparent liquid was not applied on the PVA layer of the transparent substrate before the step of forming the colored portion. A light amount adjusting member was created.

<Evaluation>
The diaphragm device using the light amount adjusting member obtained in Example 1 and Comparative Example 1 is incorporated in the light amount adjusting device, and the optical characteristics of the optical filters manufactured in Example 1 and Comparative Example 1 are evaluated as follows. did. These light quantity adjusting devices were incorporated in the lens of the photographing system, a resolution chart was photographed, and MTF was measured. Note that the spatial frequency on the image plane of the measured resolution chart is 63 line pairs / mm. As a result, the MTF in the horizontal direction of the optical filter of Example 1 in a state where the optical filter covers half of the opening (F2.4) was 61.5%. On the other hand, the result of measuring the MTF of the optical filter of Comparative Example 1 in which the light amount adjusting member that does not apply the transparent liquid before the coloring step was incorporated in the light amount adjusting device was 49.5%.

  From the above, the optical filter obtained by the manufacturing method of Example 1 has a result that the MTF value can be improved. That is, before the colored portion forming step, the light amount adjusting member obtained by forming a colored pattern after applying and swelling a transparent liquid on a transparent resin layer having liquid absorbency provided on a transparent substrate. It was found that there was a sufficient performance improvement effect.

  Furthermore, the image of the micrograph of the part in which the optical density of the colored part of the light amount adjusting member prepared in Example 1 continuously changes is shown in FIG. 4, and the optical density of the colored part of the light amount adjusting member prepared in Comparative Example 1 is The image of the micrograph of the part which changes continuously is shown in FIG. As shown in the figure, the roughness of the colored portion is less in FIG. 4 than in FIG. 5. From this result also, the light amount adjusting member prepared by the method of the present invention has the colored portion. It was found that the optical characteristics of the portion where the optical density continuously changes are excellent.

It is the schematic of the aperture blade which comprised the light quantity adjustment member concerning this invention. It is the schematic of the light quantity adjustment apparatus using the aperture blade of FIG. It is a typical block diagram of the imaging device incorporating the light quantity adjustment apparatus of FIG. It is an image of the microscope picture which shows the part from which the optical density of the coloring part of the light quantity adjustment member produced with the method of this invention changes continuously. It is an image of the microscope picture which shows the part from which the optical density of the coloring part of the light quantity adjustment member produced with the method of the comparative example changes continuously.

Explanation of symbols

100: Light quantity adjusting device (aperture device)
101, 102: Diaphragm blades 101P, 102P: Colored portion 101Q, 102Q: Light blocking member 101R, 102R: Transparent portion 101a, 102a: Slot 101b, 102b: Groove 101c, 102c: Diaphragm opening edge 103: Diaphragm blade drive lever 103a: Hole 103b, 103c: Projection pin 105: Guide pin 106: Base plate optical path hole 111: Transparent substrate 112: Liquid absorption layer 113: Transparent flattening layer 114: Antireflection film 400: Photography Optical system 401: First lens group 402: Second lens group 403: Third lens group 404: Optical low-pass filter 411: Imaging means 421: Display 422: Operation switch group 423: Actuator 431: CPU
432: Aperture drive circuit 433: CCD drive circuit 441: Amplifier circuit 442: Camera signal processing circuit 443: Recorder

Claims (10)

  In the method for producing a light amount adjusting member in which a colored portion comprising a specific optical density region containing at least a transparent resin and a color material and a transparent portion containing at least a transparent resin are formed on a transparent substrate, liquid absorbency A transparent liquid containing at least a transparent organic solvent and / or water is applied to the transparent resin layer on the surface of the transparent substrate having the transparent resin layer provided on the surface by using the first liquid applying apparatus. After the liquid resin is swollen and before the transparent resin layer is dried, the transparent resin layer is applied with a colored liquid or a colored liquid and a transparent liquid using a second liquid applying device, so that at least a specific optical The manufacturing method of the light quantity adjustment member characterized by having the process of forming the colored part which consists of a density | concentration area | region.   The first liquid application device is a micro droplet ejection device that ejects droplets from a micro nozzle row, and the width of the nozzle row is equal to or larger than the width of a light amount adjusting member to be manufactured. The method for producing a light amount adjusting member according to claim 1, wherein the transparent liquid is applied to the entire surface of the transparent substrate without a gap by scanning the transparent liquid one scan at a width equal to or greater than the width of the light amount adjusting member to be produced.   The second liquid applying device is a micro droplet ejection device that ejects droplets from a minute nozzle row, and a colored liquid or a colored liquid and a transparent liquid are transparent on the transparent resin layer swollen from the minute nozzle row. The method for producing a light amount adjusting member according to claim 1, wherein a colored portion comprising at least a specific optical density region is formed on the transparent substrate by discharging and applying a liquid.   The method for producing a light amount adjusting member according to any one of claims 1 to 3, further comprising a step of flattening by providing a transparent layer on at least the surface of the colored portion after the step of forming the colored portion. .   The method for producing a light amount adjusting member according to any one of claims 1 to 4, wherein the coloring material is a dye, a pigment, or a mixture thereof.   The method for manufacturing a light amount adjusting member according to claim 1, further comprising a step of providing an antireflection film on both surfaces of the light amount adjusting member after the step of forming the colored portion.   7. The specific optical density region according to claim 1, wherein the specific optical density region has a density distribution that changes continuously or stepwise and is formed by partially changing the type and / or applied amount of a color material. The manufacturing method of the light quantity adjustment member of 1 item | term.   A light amount adjusting member manufactured by the method for manufacturing a light amount adjusting member according to claim 1.   A light amount adjusting device comprising the light amount adjusting member according to claim 8.   An imaging apparatus comprising: a light amount adjusting device; an imaging optical system for forming a subject image; an imaging unit that photoelectrically converts the subject image; and a recording unit that records a photoelectrically converted signal. A photographing apparatus comprising: a light amount adjusting device according to claim 9 disposed in a system.