JP5411043B2 - Imaging device - Google Patents

Description

The present invention relates to an image pickup apparatus using a light shield, in which relating particularly to an imaging apparatus, such as a low-cost camera.

  For example, in a lens unit that is used with a light-shielding body sandwiched between a plurality of lenses, the surface of the light-shielding body used there is light to avoid adverse effects on the image quality formed at the tip of the lens. Therefore, it is necessary to modify the surface so as to prevent light reflection and absorb light. In addition, it is desirable that the light shielding body is manufactured by an optimum processing method that satisfies the dimensional accuracy required in the design of the optical mechanism, and a stable shape can be maintained including the assembling process. Since it is necessary to be made, stainless steel or a copper alloy is used as a material for forming a light shielding body, and the stainless steel or copper alloy is manufactured by etching or pressing. However, in this case, if the surface of the stainless steel is used as it is exposed, it will adversely affect the image formed by reflecting light on the surface, so it is necessary to modify the surface so that it does not reflect, For this purpose, for example, color is developed by electrolysis of stainless steel, or copper is oxidized with an oxidizing agent to modify the surface to black, thereby preventing light reflection.

Japanese Patent Publication No. 2009-139705 Japanese Patent Publication No. 2004-341194 Japanese Patent Publication No. 2006-189726 Japanese Patent Publication No. 9-31662 Japanese Patent Publication No. Hei 6-299394

  By the way, the surface of the black layer formed on the surface of the conventional light-shielding body has a problem that it is scratched and changes in the light-shielding property when it is rubbed in contact with an operator's hand or work tool.

The imaging device of the present invention includes a lens group including at least two lenses, a holding device that holds at least each peripheral portion of the lens group, and the lens in a state where the peripheral portion of the lens group is held by the holding device. An image pickup apparatus having a light shielding body interposed therebetween, wherein the light shielding body sequentially protects a base, a light shielding layer made of a black metal compound on the base, and a black surface of the light shielding layer. It has a translucent glass layer and has a through hole formed in the center .

  The light-shielding body of the present invention has the light-transmitting glass layer made of glass formed on the surface of the light-shielding layer, so that the light-transmitting glass can be rubbed even if it comes into contact with an operator's hand or a work tool. The presence of the layer eliminates the above-described surface damage and has an effect of stabilizing the light shielding degree based on black. Moreover, since the said light-shielding body can maintain said outstanding light-shielding function, the said imaging device using it enables imaging of various clear images.

It is sectional drawing of the lens unit containing the light-shielding body in Embodiment 1 of this invention. 1 is a conceptual cross-sectional view of an imaging apparatus according to Embodiment 1 of the present invention. It is the top view and sectional drawing of the light-shielding body shown in FIG. 1 and FIG. FIG. 4 is a detailed cross-sectional view of the light shield shown in FIG. 3.

Embodiment 1 FIG.
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. 1 to 4 illustrate an example of a light shielding body and an example of an imaging device including the same in Embodiment 1 of the present invention. FIG. 1 is a cross-sectional view of a lens unit including the light shielding body. FIG. 3A is a conceptual cross-sectional view of an example of an imaging apparatus of the present invention, FIG. 3A is a plan view of a light shielding body 3 included in FIGS. 1 and 2, and FIG. 3B is the light shielding along the line AA in FIG. FIG. 4 is another and detailed cross-sectional view taken along line AA of FIG. 3a.

  In FIG. 1, the lens unit 1 includes a pair of lenses 11, a lens 12, and a light shield 3. The lens 11, the lens 12, and the light blocking body 3 are disk-shaped bodies having the same outer diameter. As shown in FIGS. 1 to 4, the light shielding body 3 has a circular through hole in the center thereof, while the lens 11 and the lens 12 are both provided with a recess in the center of one surface of the flat plate body. Has a shape. Therefore, when the light shielding body 3 is sandwiched between the lens 11 and the lens 12 and the positions of the circular through holes at the center of the light shielding body 3 are matched with the positions of the respective depressions of the lens 11 and the lens 12, the 3 The combined body has the cross-sectional structure shown in FIGS. In a state where the pair of lenses 11 and 12 sandwich the light shielding body 3 between them, as shown in FIGS. 1 and 2, a lens-like space is generated in the central portion between the two due to the depression. Yes.

  3 and FIG. 4, the light shielding body 3 is a donut-shaped body having a rectangular cross section 31, a light shielding layer 32 formed on the entire surface of the base 31, and the light shielding. A transparent glass layer 33 made of transparent glass is formed on the surface of the layer 32. 1 to 4, as examples of the shape of the side surface of the hole forming the inner circle of the donut-shaped body, side surfaces orthogonal to both the front and back surfaces of the donut-shaped body are illustrated, but in the present invention, The surface shape of the side surface is not limited to the orthogonal side surface, and may be various shapes. For example, the surface has a gentle mountain shape at the middle of the thickness, a convex shape that swells in a steep mountain shape, a concave shape in which the middle portion is recessed opposite to the above, or an edge of the surface Examples of raised parts are exemplified.

  The constituent material of the base 31 is not particularly limited as long as the light shielding layer 32 can be formed on the surface thereof. For example, stainless steel, copper and various copper alloys, nickel, aluminum, plastics, ceramics, etc. is there. As the above stainless steel, those well known in the art can be adopted. For example, Fe—Cr—Ni alloys, ferrite alloys containing 12% (% by weight, the same applies hereinafter) or more of Cr having excellent corrosion resistance, Examples include martensitic alloys, austenitic alloys, and ferrite-austenite alloys. Copper may have a purity of 99.96% by weight or more, and the copper alloy may be phosphor bronze or brass. As nickel, various nickel alloys can be used in addition to high-purity nickel having a purity of at least 99% by weight. The plastics may have heat resistance that can be formed by the method described later on the light shielding layer 32 and the light transmissive glass layer 33 thereon, and heat resistance that is higher than the operating temperature of the imaging device of the present invention. For example, various thermoplastic resins and thermosetting resins are used. Any ceramic may be used as long as it has the same formability and heat distortion resistance as the above plastics.

  Next, an example of the light shielding body 3 will be described in detail. In FIG. 4, the light shielding layer 32 includes an underlayer 321 made of nickel plating, an intermediate layer 322 made of copper, a black coating layer 323, and a translucent glass layer 33. It is formed from four layers. Examples of the metal compound forming the black coating layer 323 were selected from the group consisting of copper oxide, chromium oxide, nickel oxide, zinc / chromium / silver oxide, and dyed aluminum oxide. At least one is exemplified.

The nickel plating for forming the base layer 321 and the copper plating for forming the intermediate layer 322 may be formed by methods and conditions conventionally known in the art. For example, the nickel plating is a nickel strike plating bath. The copper plating 322 may be formed by plating at 1 A / dm ² for 10 minutes using a copper sulfate plating bath, and the thickness of the nickel plating is 0. 5A / dm ² . The thickness of the copper plating may be about 1 μm to 2 μm.

  In the present invention, the translucent glass layer 33 is formed of translucent glass, and the glass material is formed of a translucent material capable of forming it on the light shielding body 32. There is no particular limitation as long as it has any heat resistance as defined in JIS K5600-6-3 from the viewpoint of ease of formation on the surface of the light shielding body 32 and stability of mechanical strength after the formation. Further, the temperature that can be formed on the light shielding body 32 is about room temperature to 60 ° C., the average thickness of the translucent glass layer 33 is about 2 μm to 4 μm, and the surface hardness measured by the pencil hardness method is 4H. The above is preferable.

Examples of the translucent glass may be, for example, inorganic glasses, organic glasses, chemical or physical mixtures of inorganic glass and organic glass, and the like. For example, it may be various kinds of ordinary glasses mainly composed of SiO ₂ , and examples of organic glasses include Si—R ₃ group (for example, R is an alkyl group, aralkyl group, OH group) in the SiO main chain. Are substituted. In addition to the above, those having good hardness and transparency such as methacrylic resin, methyl methacrylate resin, polystyrene, unsaturated polyester resin, and polyvinyl chloride are exemplified.

  When the translucent glass layer 33 is formed of the above inorganic glass, the layer 33 can be formed by, for example, a normal sol-gel method or a super sol-gel method obtained by improving the sol-gel method. That is, in the normal sol-gel method, water or a reaction catalyst is added to a raw material mixture, and a sol is generated by hydrolysis or condensation reaction. Further, the reaction proceeds, or the solvent is removed to gel, and then the gel is heated. Harden and vitrify. On the other hand, in the super sol-gel method, a reaction catalyst is added to a raw material mixture, the solvent is removed, hydrolysis and condensation reactions are started by moisture in the air, and then the glass is cured at room temperature. Therefore, in the normal sol-gel method, heating is necessary for vitrification of the gel. Therefore, there is a possibility that a part of the light shielding body 32 is collapsed or deformed by the heating. There is an advantage that the above-mentioned problems do not occur because the glass is vitrified.

  Examples of the material used for the super sol-gel method include nanocomposites. A nanocomposite is a sea island in which a layer of silica particles is composed of one ultrafine polymer particle having a particle size of about 1 to 100 nm or a mixture of various polymer particles, with silica as the sea and polymers as islands. For example, a product name SSG coat of Nittobo Co., Ltd. is exemplified. In addition, the nanocomposite is cured at room temperature to form a transparent glassy film, and thus is particularly suitable as a material for forming the translucent glass layer 33 of the present invention.

  Next, an example of a method for manufacturing the light shield 3 according to the present invention will be described. In this production example, in order to form a mechanically stable light shielding layer 32 on the surface of the substrate 31, it is preferable to pretreat the surface and then form the light shielding layer 32. As the pretreatment method, after degreasing using an alkaline detergent and electrolytic degreasing, the surface is activated by acid cleaning using an acid such as hydrochloric acid, and the light shielding layer 32 of the present invention is formed by the method described later. To do.

  In the present invention, the light shielding layer 32 may be directly formed on the surface of the light shielding body 3 cleaned by the above method by the following method, but preferably chemically compatible with the material constituting the light shielding layer 32. It is preferable to form an affinity layer made of a third material having a property and form the light shielding layer 32 thereon. As the affinity layer, when the light shielding layer 32 is made of copper oxide / chromium oxide / nickel oxide, a nickel plating layer is preferable. When the light shielding layer 32 is made of zinc / chromium / silver oxide, a nickel + copper plating layer is used. Is preferred.

  The average thickness of the light shielding layer 32 formed on the surface of the substrate 31 (stainless steel surface) is generally about 3 to 5 μm, preferably about 2 to 3 μm, and particularly preferably about 1 to 2 μm.

  Next, an example of the image pickup apparatus of the present invention will be described with reference to FIG. 2. The image pickup apparatus example includes the lens unit 1, the filter 4, the image sensor 5, and the outer frame body 6 described in detail so far. Yes. The outer frame body 6 is a cylindrical body that can be divided in half, and has a ring-shaped groove portion 61 into which the lens unit 1 can be inserted and a ring-shaped protrusion 62 for installing the filter 4 on its inner wall. In the imaging apparatus, the filter 4 is installed on the ring-shaped protrusion 62 in a state where the outer frame body 6 is almost halved, the lens unit 1 is inserted into the ring-shaped groove 61, and then the outer frame body 6 is halved. The state is changed from the state to the tube state, and the image sensor 5 is installed in the lower portion of the tube state.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.
Example 1.
The base 31 of the light-shielding body 3 is made of Fe—Cr—Ni stainless steel having a Cr content of 18% by weight, a Ni content of 8% by weight, and the balance being Fe. Using a donut-shaped stainless steel plate having a diameter of 0.5 mm and an inner diameter of 0.5 mm, the entire surface is first cleaned by degreasing, pickling, and electrolytic degreasing sequentially, and then 5 A / dm in a nickel strike plating bath at a temperature of 25 ° C. ^By plating at a current density of ² for 5 minutes, a base nickel layer having a thickness of 0.5 μm is formed, and further, a current of 1 A / dm ² is applied on the base nickel layer in a copper sulfate plating bath at a temperature of 25 ° C. After plating at a density of 10 minutes to form a copper plating layer having a thickness of 2 μm, the copper plating layer is immersed in a sodium chlorite solution at a temperature of 95 ° C. for 1 minute and subjected to oxidation treatment, whereby the copper plating is performed. The entire surface of the layer Average thickness was formed a black copper oxide layer of 2μm to. Next, an SSG coat having a trade name of Nittobo Co., Ltd. was applied to the entire surface of the black copper oxide layer, and the SSG coat was cured and vitrified by allowing it to stand at room temperature in the atmosphere for 7 days, so that the average thickness was 2 μm. A light-shielding layer of Example 1 was obtained by forming a light glass layer.

Example 2
The base 31 of the light-shielding body 3 is made of Fe—Cr—Ni stainless steel having a Cr content of 18% by weight, a Ni content of 8% by weight and the balance being Fe, and a thickness of 0.02 mm. Using a donut-shaped stainless steel plate having a 5 mm inner diameter and 0.5 mm inner diameter, the entire surface is first cleaned by degreasing, pickling, and electrolytic degreasing, and then plated for 5 minutes at a voltage of 4 V in a black chrome plating bath at a temperature of 20 ° C. A black chromium oxide layer having a thickness of 0.1 μm was formed. Next, the SSG coat is applied to the entire surface of the black chromium oxide layer, and is left to stand for 7 days at room temperature in the atmosphere. The SSG coat is cured and vitrified to obtain a translucent glass layer having an average thickness of 2 μm. As a result, a light shielding layer of Example 2 was obtained.

Example 3
The donut-shaped stainless steel plate used in the first embodiment is used as the base 31 of the light-shielding body 3, and the entire surface is first cleaned by degreasing, pickling, and electrolytic degreasing, and then in a nickel strike plating bath at a temperature of 25 ° C. By plating at a current density of 5 A / dm ² for 5 minutes, a 0.5 μm-thick underlying nickel plating layer is formed, and the surface of the nickel plating layer is washed with dilute sulfuric acid, and then a black nickel plating bath (30 ° C.) Was plated for 5 minutes at a current density of 0.1 A / dm ² to form a black nickel oxide layer having a thickness of 0.1 μm. Next, the SSG coat is applied to the entire surface of the black nickel oxide layer, and the SSG coat is cured and vitrified by allowing it to stand at room temperature in the atmosphere for 7 days. The translucent glass layer having an average thickness of 2 μm. As a result, a light shielding layer of Example 3 was obtained.

Example 4
The donut-shaped stainless steel plate used in the first embodiment is used as the base 31 of the light-shielding body 3, and the entire surface is first cleaned by degreasing, pickling, and electrolytic degreasing, and then in a nickel strike plating bath (25 ° C.). A base nickel layer having a thickness of 0.5 μm is formed by plating at a current density of 5 A / dm ² for 5 minutes, and then 1 A / dm ^{2 in a} copper sulfate plating bath (25 ° C.) on the base nickel layer. After forming a copper plating layer having a thickness of 2 μm for 10 minutes at a current density of 15 μm, the copper plating layer was further coated with a non-cyanide zinc plating bath (30 ° C.) at a current density of 4 A / dm ² on the copper plating layer. After partial plating and forming a zinc plating layer having a thickness of 5 μm, the entire surface of the zinc plating layer is immersed in the black chromate treatment solution (20 ° C.) for 3 minutes and oxidized. 0.1 Oxide black zinc-chromium-silver layer thickness of less than m (black chromate film) was formed. Next, the SSG coat is applied to the entire surface of the zinc oxide / chromium / silver layer, and left for 7 days at room temperature in the atmosphere to cure and vitrify the SSG coat, so that the average thickness is 2 μm. A light-transmitting glass layer was formed to obtain a light-shielding layer of Example 4.

Example 5.
The doughnut-shaped aluminum plate used in the first embodiment is used as the base 31 of the light-shielding body 3. First, the entire surface is cleaned by degreasing and pickling, and then 1. Anodized film treatment bath (20 ° C.) By oxidizing at a current density of 7 A / dm ² , an anodic oxide film layer having a thickness of 10 μm is formed, and then a black dyeing solution (using Clariant Japan's Sanodal Deep Black MLW) is maintained at 55 ° C. It was immersed in it for 15 minutes, washed with water, then immersed in a nickel acetate solution (97 ° C.) for 15 minutes and sealed to form a black aluminum anodic oxide film treatment (black dyeing) layer. Next, the SSG coat is applied to the entire surface of the black aluminum anodized film treatment (black dyeing) layer, and the SSG coat is cured and vitrified by leaving it at room temperature in the atmosphere for 7 days to obtain an average thickness. Formed a light-transmitting glass layer of 2 μm to obtain a light-shielding layer of Example 5.

Example 6
A donut-shaped copper plate having a purity of 99.9%, a thickness of 0.3 mm, an outer shape of 3 mm, and an inner diameter of 0.5 mm is used as the base 31 of the light shielding body 3. First, the entire surface is cleaned by degreasing, acid etching, and acid cleaning. Then, it was immersed in a sodium chlorite solution (95 ° C.) for 1 minute and oxidized to form a black copper oxide layer having an average thickness of 2 μm on the entire copper surface. Next, the SSG coat is applied to the entire surface of the black copper oxide layer, and the SSG coat is cured and vitrified by allowing it to stand at room temperature in the atmosphere for 7 days, so that the average thickness is 2 μm. Got.

Example 7.
The donut-shaped copper plate used in Example 6 was used as the base 31 of the light-shielding body 3, and the entire surface was first cleaned by degreasing, pickling, and electrolytic degreasing, and then 4 V in a black chrome plating bath (20 ° C.). Was plated for 5 minutes to form a black chromium oxide layer having a thickness of 0.1 μm. Next, the SSG coat is applied to the entire surface of the black chromium oxide layer, and is left to stand at room temperature in the atmosphere for 7 days to cure and vitrify the SSG coat, thereby translucent glass layer having an average thickness of 2 μm. As a result, a light shielding layer of Example 7 was obtained.

Example 8
The donut-shaped copper plate used in Example 6 was used as the base 31 of the light-shielding body 3, and the entire surface was first cleaned by degreasing, pickling, and electrolytic degreasing, and then 5A in a nickel strike plating bath (25 ° C.). By plating for 5 minutes at a current density of / dm ^2, a 0.5 μm-thick base nickel layer is formed, and the surface of the nickel plating layer is washed with dilute sulfuric acid and then washed with a black nickel plating bath (30 ° C.). The light shielding body of Example 8 having a black nickel oxide layer having a thickness of 0.1 μm was produced by plating at a current density of 1 A / dm ² for 5 minutes. Next, the SSG coat is applied to the entire surface of the black nickel oxide layer, and the SSG coat is cured and vitrified by allowing it to stand at room temperature in the atmosphere for 7 days. The translucent glass layer having an average thickness of 2 μm. As a result, a light shielding layer of Example 8 was obtained.

Example 9.
The doughnut-shaped copper plate used in Example 6 was used as the base 31 of the light-shielding body 3, and the entire surface was first cleaned by degreasing, pickling, and electrolytic degreasing, and 1 A / in a copper sulfate plating bath (25 ° C.). After plating at a current density of dm ² for 10 minutes to form a copper plating layer having a thickness of 2 μm, a current density of 4 A / dm ² is further applied on the copper plating layer in a non-cyanide zinc plating bath (30 ° C.). After forming a zinc plating layer with a thickness of 15 μm by immersing the zinc plating layer in the black chromate treatment solution (20 ° C.) for 3 minutes and oxidizing it, the entire surface of the zinc plating layer is obtained. A light shielding body of Example 9 having a black zinc oxide / chromium / silver layer (black chromate film) having a thickness of 0.1 μm or less was prepared. Next, the SSG coat is applied to the entire surface of the black zinc oxide / chromium / silver layer, and is left to stand for 7 days at room temperature in the atmosphere. The SSG coat is cured and vitrified, and the average thickness is 2 μm. A light-shielding layer of Example 9 was obtained by forming a light glass layer.

  Next, for the stainless steel plate, copper plate, or aluminum plate with each black light shielding layer obtained in Examples 1 to 9, and as Comparative Example 1, there is no translucent glass layer as in Example 1 above. As a comparative example 2, a material that differs from Example 5 only in that there is no translucent glass layer is used. Also, as a comparative example 3, a translucent glass layer is different from Example 6. Compared to the effects of using different ones, there is no point, and by adding a translucent glass layer, the surface of the black shading layer becomes much more stable, easy to handle and easy to use. It was confirmed that

In particular, in the comparison between Comparative Example 1 and Example 1 whose surface is mechanically weak against external force, and in the comparison between Comparative Example 3 and Example 6 similar to Comparative Example 1, the presence or absence of a translucent glass layer The difference by was remarkable. In addition, since the fine particles of glass are added as a matting agent (matting agent) to the coating agent (base) for forming the translucent glass layer, the reflectance can be easily adjusted over a wide range. The light-shielding body can be provided with a stable characteristic for a wide range of materials as being easy to handle.

  Since the light-shielding body of the present invention has extremely excellent light-shielding performance, the imaging device of the present invention using the light-shielding body is a light-shielding plate for a lens of a device intended for imaging such as a portable camera, digital camera, video camera, etc. And suitable for an imaging apparatus used in the field of optical equipment.

1: lens unit, 3: light-shielding body, 32: light-shielding layer, 33: translucent glass layer,
4: Filter, 5: Image sensor, 6: Outer frame, 61: Ring-shaped groove,
62: Ring-shaped protrusion

Claims (6)

A lens group including at least two lenses, a holding device that holds at least each peripheral portion of the lens group, and a light shield inserted between the lenses in a state where the peripheral portion of the lens group is held by the holding device. An image pickup apparatus having a body, wherein the light-shielding body protects the black color of the surface of the base, the light-shielding layer made of a black metal compound, and the light-shielding layer, and has heat resistance. have a sexual glass layer, and an imaging apparatus characterized by through-holes in the central portion is formed. The said base | substrate is plate shape, Comprising: It forms with at least 1 type chosen from the group which consists of stainless steel, nickel, copper, a copper alloy, aluminum, a plastics, and ceramics. Imaging device . The black metal compound is at least one selected from the group consisting of copper oxide, chromium oxide, nickel oxide, zinc oxide, and aluminum oxide dyed with a dye. Item 2. The imaging device according to Item 1. The imaging device according to claim 1, wherein the translucent glass layer has a thickness of 2 μm to 4 μm. The imaging device according to claim 4, wherein the translucent glass layer is made of a mixture of an inorganic glass and an organic polymer. The imaging device according to claim 5, wherein the translucent glass layer is formed of a nanocomposite composed of silica particles and an organic polymer having an average particle diameter of 1 to 100 nanometers.

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