JP7225321B2 - Optical equipment and optical elements - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical element having a light shielding film on its non-optically effective surface and an optical apparatus having the optical element.

In lenses generally used in optical equipment, incident light is emitted from the surface opposite to the incident surface, but a very small portion of the light is internally reflected at the end surface (edge surface) of the lens. For this reason, in an optical device that uses a combination of a large number of lenses, a light shielding film is provided on the end surface (edge surface) so as to prevent deterioration of image quality due to internal reflection.

Patent Literature 1 discloses an optical element having a stepped shape on the outer periphery of the optical element, and a light shielding film provided on a part of the non-optically effective surface of the stepped shape. In the optical element disclosed in Cited Document 1, the light-shielding film formed on the flat portion of the non-optically effective surface is made thinner than the light-shielding film provided on the curved surface portion, thereby suppressing total reflection on the curved surface portion and reducing the weight. An optical element with excellent light shielding performance is described.

JP 2013-114235 A

In Patent Document 1, since the optical element is provided with a light shielding film having a uniform hardness, the optical element tends to be decentered with respect to the optical axis in the lens barrel due to the film thickness distribution of the light shielding film. .

In an optical element having a stepped shape, when a light shielding film is provided on the non-optically effective surface perpendicular to the optical axis, the light is blocked due to the film thickness distribution of the light shielding film on the non-optically effective surface perpendicular to the optical axis. Eccentricity with respect to the axis occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical apparatus capable of reducing the eccentricity of a lens with respect to the optical axis in a lens barrel even when a light shielding film is provided on a non-optically effective surface perpendicular to the optical axis.

An optical instrument of the present invention is an optical instrument comprising an optical element and a lens barrel holding the optical element therein, wherein the optical element comprises a base material having an optically effective surface and a non-optically effective surface; a light shielding film provided on at least part of the non-optically effective surface of the base material, the light shielding film having a first portion and a second portion; The first portion is lower in hardness than the second portion, and the optical element is in contact with the lens barrel at the first portion.

An optical element of the present invention is an optical element comprising a substrate having an optically effective surface and a non-optically effective surface, and a light-shielding film provided on at least part of the non-optically effective surface of the substrate. The light shielding film has a first portion arranged so as to be in contact with the lens barrel holding the optical element inside, and a second portion, and the first portion is the second portion. It is characterized by having a lower hardness than the second part .

Advantageous Effects of Invention According to the present invention, it is possible to provide an optical element and an optical apparatus having light shielding performance and a small amount of eccentricity with respect to the optical axis of the lens in the lens barrel.

It is a schematic diagram of the cross section of the optical instrument of the present invention. FIG. 4 is a schematic diagram of an optical element having a stepped portion on the non-optically effective surface of the outer peripheral portion; FIG. 4 is a schematic diagram of an optical element on which light shielding films having different hardnesses are formed; 1 is a schematic diagram of an optical element formed with a light-shielding film having a hardness difference of Example 1. FIG. 4 is a schematic diagram of a light shielding film obtained by grinding a part of the light shielding film in the process of manufacturing the light shielding film of Example 1. FIG. FIG. 4 is a schematic diagram of a light-shielding film coated with a second paint in the process of manufacturing the light-shielding film of Example 1; 1 is a schematic diagram of an optical element formed with a light shielding film produced in Example 1. FIG. FIG. 11 is a schematic diagram of an optical element on which a light shielding film of Example 6 is formed. FIG. 11 is a schematic diagram showing a coating method using the dispenser of Example 7; FIG. 11 is a schematic diagram showing a coating method in which the second coating material of Example 7 is applied; FIG. 12 is a schematic view of the optical element coated with the second coating material in Example 9, viewed from the R1 surface side. FIG. 11 is a schematic diagram of a meniscus-shaped optical element used in Example 8; FIG. 11 is a schematic diagram of an optical element on which a light shielding film of Example 9 is formed.

Preferred embodiments of the present invention are described in detail below.

(optical equipment)
The optical instrument of the present invention can be used for telescopes, binoculars, microscopes, cameras, endoscopes, etc., which have optical elements in their barrels.

The optical apparatus of the present invention will be described below using an example of a camera lens unit.

As shown in FIG. 1, in a lens unit (optical device) 1 of the present invention, a lens barrel 2 holds an optical element 3 inside. The optical element 3 is in contact with the lens barrel 2 through a light shielding film 4 provided on the non-optically effective surface of the substrate 5 .

The lens barrel 2 is made of metal or resin.

(optical element)
As shown in FIG. 2, the substrate 5 of the optical element (lens) 3 of the present invention has optically effective surfaces R1 and R2, and at least non-optically effective surfaces (edge surfaces) perpendicular to the optical axis L. ) a and c. Glass or resin can be used as the material of the base material 5 .

For example, as shown in FIG. 2, the base material 5 has non-optically effective surfaces (edge surfaces) b and d parallel to the optical axis L and non-optically effective surfaces perpendicular to the optical axis L. (Edge surface) a and c are formed. This shape is called a stepped shape. In this specification, the direction perpendicular to the optical axis includes not only 90° to the optical axis but also 90°±1°. Moreover, in this specification, parallel includes not only being parallel but also being inclined ±3° from parallel.

As shown in FIG. 2, the optical element (lens) 3 of the present invention has a light shielding film 4 on a plane c perpendicular to the optical axis L. As shown in FIG.

The light shielding film 4 has at least resin and colorant.

As the resin used for the light shielding film 4, a thermosetting resin selected from epoxy resin, alkyd resin, and acrylic resin can be appropriately selected and used. Among these, it is more preferable to use an epoxy resin because of its good dimensional stability.

The light shielding film 4 preferably contains inorganic fine particles in order to adjust the refractive index of the light shielding film 4 . The use of inorganic fine particles having a refractive index (nd) of 2.1 or more can increase the refractive index of the light-shielding film 3, which generally has a lower refractive index than the base material 5, thereby reducing internal reflection. effective. As inorganic fine particles having a refractive index (nd) of 2.1 or more, fine particles of titanium oxide, zirconium oxide, aluminum oxide, yttrium oxide, cadmium oxide, diamond, strontium titanate, and germanium can be used. Among these, titanium oxide and zirconium oxide having a refractive index (nd) of 2.1 or more and 3.5 or less are preferably used. When the refractive index of the inorganic fine particles is less than 2.1, the refractive index of the light-shielding film is low, so that the difference in refractive index between the substrate and the light-shielding film increases, resulting in increased internal reflection.

A dye or a pigment can be used as the colorant, but it is preferable to use a dye because it is easily dispersed uniformly. At least one black pigment selected from carbon black, titanium black, copper oxide, and iron oxide (red iron oxide) can be used as the pigment. Dyes that can be used include anthraquinone dyes, phthalocyanine dyes, stilbenzene dyes, pyrazolone dyes, thiazole dyes, carbonium dyes, and azine dyes. The content of the dye contained in the light-shielding film of the present invention is 13.0% by mass or more and 50.0% by mass or less, preferably 13.0% by mass, relative to the light-shielding film when the dye is used alone. More than 40.0 mass % or less is preferable.

FIG. 3 is an enlarged schematic view of the periphery of the optical element 3 near the non-optically effective surface c. As shown in FIG. 3, the optical element 3 is provided with a light shielding film 4 on the non-optically effective surface (edge surface) c of the substrate 21 in the direction perpendicular to the optical axis L. As shown in FIG. The light shielding film 4 on the surface portion f2 away from the optical axis L is softer than the light shielding film 4 on the surface portion f1 close to the optical axis L. - 特許庁The optical element 3 is held in contact with the lens barrel at the soft portion f2 of the light shielding film 4 . In the optical element 3 of the present invention, the light shielding film 4 in the portion that contacts the lens barrel 2 is soft, so that the surface of the light shielding film 4 is more likely to be dented when the optical element 3 is incorporated in the lens barrel 2 . As a result, even if there is a film thickness difference in the light shielding film 4 before it is incorporated into the lens barrel 2, the light shielding film 4 can absorb the film thickness difference.

In the light shielding film 4 formed on the surface c in the direction perpendicular to the optical axis L of the optical element, the portion f1 adjacent to the portion in contact with the lens barrel 2 and not in contact with the lens barrel 2 is hard. , the relative movement of the lens barrel 2 and the optical element 3 in the direction perpendicular to the optical axis is suppressed. Since the optical element 3 of the present invention has such a structure, the eccentricity of the lens in the barrel 2 with respect to the optical axis can be reduced.

As for the effect of the film thickness difference in the light shielding film 4 on the amount of eccentricity, the smaller the lens diameter, the greater the amount of eccentricity if the film thickness difference is the same. As a lens for a single-lens reflex camera, a relatively small outer diameter φ25 mm lens is taken as an example. In order to keep the amount of eccentricity that increases due to the formation of the light shielding film 4 to 15 seconds or less, the thickness difference in the light shielding film 4 when the optical element 3 (lens) is assembled to the lens barrel 2 should be approximately 1 μm or less. must be Although it depends on the coating method, when coating is performed so as to have a thickness of about 10 μm, the variation in thickness of the light shielding film 4 after coating is 1 to 2 μm.

Therefore, if it is possible to dent the light-shielding film in contact with the light shielding film to absorb film thickness variations of up to about 1 μm, it is possible to suppress an increase in the amount of eccentricity. can. Specifically, when an optical element coated with a light-shielding film with a thickness of 10 μm formed by general light-shielding paint GT-7II (product name, manufactured by Canon Chemicals Co., Ltd.) and baked at 80 ° C. is incorporated into a lens barrel. is about 0.5 μm. By reducing the hardness of the light shielding film in contact with the lens barrel by about half, it is possible to recess the light shielding film by about 1 μm.

The film thickness measurement of the light shielding film 4 is confirmed by cutting the coated lens and observing the cross section with a microscope or SEM. Further, the film thickness difference of the light shielding film 4 can be obtained by preparing a plurality of cut surfaces and observing the cross sections in the same manner.

The hardness of the light-shielding film 4 formed of light-shielding paint GT-7II (product name, manufactured by Canon Kasei Co., Ltd.) measured by the nanoindentation method, in which the hardness is calculated from the load and displacement of a diamond indenter, is approximately 10 Vickers hardness. 0 to 11.5 GPa. In the case of the light-shielding film 4 with a film thickness of 10 μm and this hardness, the amount of dent when incorporated in the lens barrel is about 0.5 μm at maximum. can let

The portion f2 of the light shielding film 4 that is in contact with the optical element on the plane c perpendicular to the optical axis preferably has a Vickers hardness of 4.5 GPa or more and 9.5 GPa or less. If the hardness of the portion f2 of the light-shielding film 4 is less than 4.5 GPa, the optical element wobbles in the lens barrel when the optical element is assembled in the lens barrel, and sufficient positional accuracy cannot be obtained. Further, when the hardness of the portion f2 of the light shielding film 4 exceeds 9.5 GPa, the amount of recession is reduced and the positional accuracy is lowered.

The Vickers hardness of the portion f2 of the light shielding film 4 that is in contact with the lens barrel 2 is preferably lower than that of the portion f1 of the light shielding film 4 that is not in contact with the lens barrel 2 by 0.8 GPa or more, and is lower by 1.0 GPa or more. is more preferred. If the hardness is lower than 0.8 GPa, it is possible to suppress radial blurring of the optical element within the lens barrel 2 .

The average film thickness of the light shielding film 4 is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less. If it is less than 3 μm, the light shielding performance is lowered. Moreover, if it exceeds 50 μm, the positional accuracy is lowered.

(Method for manufacturing optical element)
As the light-shielding paint used for manufacturing the optical element 3, resins such as GT-7II and GT-20 (trade name, manufactured by Canon Chemical Industries, Ltd.), dyes, and paints containing various fine particles as main components can be used. In addition, if the optical element to be used satisfies the properties required as a light-shielding film such as optical properties, refractive index, film durability, etc., it is not limited to this, and the light-shielding paint may be diluted with a solvent or the like. good too.

The light-shielding paint can be applied to the non-optically effective surface (edge surface) by direct coating methods such as the bar coating method, spray coating method, dip coating method, and inkjet method, as well as other methods such as the brush/sponge coating method and the roll coating method. There is a method of coating through a medium.

In order to make the portion f2 in contact with the lens barrel 2 of the light shielding film 4 softer than the portion f1 not in contact with the lens barrel 2, the optical element 3 is produced by the following method. In the first method, after applying the light-shielding paint to the entire non-optically effective surface (edge surface), before the light-shielding paint dries, the light-shielding paint diluted with a solvent is applied to the portion f2 to be softened. By repeatedly applying the paint before the drying of the paint is finished, it is possible to obtain a uniform film thickness to some extent, and the hardness is lowered because part of the solvent remains in the light-shielding film.

The second method is the first method, in which the coating amount of the light-shielding paint is partially changed when the light-shielding paint is applied to the entire non-optically effective surface (edge surface). For example, the light shielding paint is applied with a reduced coating amount on the portion f2 of the non-optically effective surface (edge surface) that is not in contact with the lens barrel.

In the third method, a light-shielding paint is applied to the entire surface of the non-optically effective surface (edge surface), and after drying and baking, the portion f2 of the light-shielding film in contact with the lens barrel is physically or chemically removed. Remove, apply a light-shielding paint diluted with a solvent, dry, and bake. In addition, it is also possible to provide a difference in hardness by lowering the temperature in the subsequent drying/firing process between the initial drying/firing process and the subsequent drying/firing process.

A fourth method is to apply a thick layer of light-shielding paint to the entire non-optically effective surface (edge surface), and then rotate the optical element at high speed around the optical axis K before it dries sufficiently. The resin component of is moved to the outer peripheral portion. This makes it possible to soften the light shielding film at the portion f2 in contact with the lens barrel 2 . At this time, since the centrifugal force acting on the non-optically effective surface (edge surface) changes depending on the lens diameter, the smaller the diameter of the lens, the higher the number of revolutions required.

(Method for manufacturing optical equipment)
The optical device 1 of the present invention can be manufactured by inserting the optical element 3 into the lens barrel 2 until it abuts against it, and then tightening it with a pressing ring, which is a lens holding member, so that the lens can be fixed.

The configuration of the optical element of each example of the present invention will be specifically described below. However, the present invention is not limited to such embodiments, and various modifications and changes are possible within the scope of the gist thereof.

(Evaluation method)
Examples and comparative examples were evaluated by the following methods.

(Measurement of hardness of light shielding film)
The hardness of the light-shielding film was measured by using a nanoindenter (manufactured by MTS, (product name)) and pressing a diamond indenter into the surface of the light-shielding film to measure the strength of each film surface. The hardness was measured at portions of the light shielding film 4 having different hardnesses. Specifically, the light-shielding film 4 of Example 1 shown in FIG. The h3 portion is positioned 0.5 to 1.5 mm from the center of the width to the outer peripheral side within the width of 3 mm of the second edge surface c perpendicular to the optical axis in the figure. The measured h1 portion is located 0.5 to 1.5 mm from the center of the width toward the center of the lens within the width of 3 mm of the second edge surface c perpendicular to the optical axis in the drawing.

(Evaluation of eccentricity)
The amount of eccentricity increased by forming the light shielding film was measured. The transmission eccentricity was measured using an optical axis measuring instrument (Opti Centric MOT manufactured by Optronics). The transmission eccentricity was measured by irradiating the lens fixed to the jig with parallel light and rotating the lens together with the jig. At this time, the maximum amount of movement of the image at the focal point was measured, and the value obtained by dividing this length by the lens focal length and taking the arctangent was evaluated.

The smaller the transmission eccentricity associated with the formation of the light shielding film, the smaller the inclination of the lens in the lens barrel and the better the positional accuracy. In general, if the amount of eccentricity is 15 seconds or less, it is considered ideal because there is almost no effect on the image, and evaluation was made according to the following criteria.
A: The amount of eccentricity is 15 seconds or less, and there is almost no effect on the image.
B: The amount of eccentricity exceeds 15 seconds and is 20 seconds or less, and there is little effect on the image.
C: The amount of eccentricity exceeds 20 seconds and affects the image.

(Example 1)
In Example 1, the optical element 3 provided with the light shielding film 4 shown in FIG. 4 was manufactured. The radius of curvature of the optically effective surface R1 of the optical element 3 used in Example 1 was 35.0 mm, and the radius of curvature of the optically effective surface R2 was 80 mm. The maximum perimeter of the effective optical surface R1 was φ46.0 mm, and the maximum perimeter of the effective optical surface R2 was φ60 mm. Also, on the edge surface c, about 1.5 mm from the outermost periphery to the inner periphery was a portion for holding the optical element in the lens barrel. The width of the edge surface a was 3 mm, and the width of the edge surface c was 4 mm.

In Example 1, a light-shielding film was produced by a method of forming a groove by scraping a portion of the light-shielding film formed on the edge surface c, and then filling the groove with a light-shielding paint having a different paint dilution ratio.

The light-shielding film was applied by applying a light-shielding material GT-7II (manufactured by Canon Kasei Co., Ltd.) to the edge surface by a sponge coating method while the optically effective surface side R2 of the base material 21 was attracted to and rotated by the suction rotation shaft of the coating device. After the entire edge surface was black and the film was sufficiently thick, it was air-dried for 1 hour and then fired at 80° C. for 2 hours. The average film thickness of the light shielding film formed on the edge surface c at this time was 10 μm. Next, as shown in FIG. 5, 2 mm from the outer peripheral portion of the light shielding film h1 formed on the c-plane was machined to a depth of approximately 5 μm in the circumferential direction. After cleaning the optical element, a second paint h3 prepared by diluting GT-7II and thinner at a mass ratio of 1:0.5 is placed in the groove on the outer periphery formed by the machining using a manual dispenser. A light-shielding film shown in FIG. 6 was produced. After that, the diluted paint that protruded onto the unground portion of the edge surface c was wiped off with a wiper. Next, after air-drying for 1 hour, baking was performed at 80° C. for 2 hours. Further, in this state, grinding was performed by machining so that the film thickness of the light shielding film on the edge surface c was uniform, and the optical element having the light shielding film shown in FIG. 7 was manufactured.

The evaluation results are shown in Table 1.

(Example 2)
In Example 2, a light-shielding film was formed in the same manner as in Example 1, except that a second paint obtained by diluting GT-7II and thinner at a mass ratio of 1:1 was used to produce an optical element and an optical device. .

The evaluation results are shown in Table 1.

The reason why the dilution rate of the second paint was changed in Example 2 is to change the hardness of the light shielding film portion formed with the second paint. In other words, by increasing the dilution rate, the ratio of the organic solvent, which is the thinner that eventually remains in the paint, increases, and conversely, the ratio of fine particles such as silica contained in the paint decreases, so the coating film hardness decreases. Conceivable.

(Example 3)
In Example 3, a light-shielding film was formed in the same manner as in Example 1, except that the second paint obtained by diluting GT-7II and thinner at a mass ratio of 1:2 was used, and an optical element and an optical instrument were produced. .

The evaluation results are shown in Table 1.

(Example 4)
In Example 4, a light-shielding film was formed in the same manner as in Example 1, except that a second paint obtained by diluting GT-7II and thinner at a mass ratio of 1:3 was used, and an optical element and an optical device were produced. .

The evaluation results are shown in Table 1.

(Example 5)
In Example 5, a light-shielding film was formed in the same manner as in Example 1, except that a second paint obtained by diluting GT-7II and thinner at a mass ratio of 1:4 was used to produce optical elements and optical equipment. .

The evaluation results are shown in Table 1.

(Comparative example 1)
In Comparative Example 1, unlike Example 1, a light-shielding film was produced without using the second paint.

In Comparative Example 1, an optical element similar to the optical element used in Example 1 was used to form a light shielding film. For the application of the light shielding film, the light shielding film GT-7II (manufactured by Canon Kasei Co., Ltd.) was applied to the edge surface by a sponge coating method while the optically effective surface side R2 of the substrate 21 was attracted to and rotated by the suction rotary shaft of the coating device. After the entire edge surface was black and the film was sufficiently thick, it was air-dried for 1 hour and then fired at 80° C. for 2 hours. The average film thickness of the light shielding film formed on the edge surface c at this time was 10 μm.

The evaluation results are shown in Table 1.

(Comparative example 2)
In Comparative Example 2, an optical element similar to the optical element used in Example 1 was used to form a light shielding film. In Comparative Example 2, the light-shielding film was applied by sponge coating a light-shielding material GT-7II (manufactured by Canon Kasei Co., Ltd.) on the edge surface while the optically effective surface side R2 of the base material 21 was attracted to the suction rotary shaft of the coating device and rotated. coated with After the entire edge surface was black and the film was sufficiently thick, it was air-dried for 1 hour and then fired at 80° C. for 2 hours. The average film thickness of the light shielding film formed on the edge surface c at this time was 10 μm.

Next, as shown in FIG. 5, 2 mm from the outer peripheral portion of the light shielding film h1 formed on the c-plane was machined to a depth of approximately 5 μm in the circumferential direction. After cleaning the optical element, the GT-7II paint h3 was placed again in the grooves formed by the machining on the outer periphery using a manual dispenser to produce the light-shielding film shown in FIG. After that, the diluted paint that protruded onto the unground portion of the edge surface c was wiped off with a wiper. Next, after air-drying for 1 hour, baking was performed at 80° C. for 2 hours. Further, in this state, grinding was performed by machining so that the film thickness of the light shielding film on the edge surface c was uniform, and an optical element having the light shielding film shown in FIG. 7 was manufactured.

The evaluation results are shown in Table 1.

(Comparative Example 3)
In Comparative Example 3, an optical element similar to the optical element used in Example 1 was used to form a light shielding film. In Comparative Example 3, the light-shielding film was applied to the edge surface while the optically effective surface side R2 of the optical element 21 was being attracted to the suction rotation shaft of the coating device and rotated. was diluted at a mass ratio of 1:4 and applied by a sponge coating method. Next, after air-drying for 1 hour, baking was performed at 80° C. for 2 hours to form a light-shielding film.

(Example 6)
In Example 6, the optical element 3 provided with the light shielding film 4 shown in FIG. 8 was produced. The substrate 21 used in Example 6 had the same shape as in Example 1. Also, in the edge surface c, about 1.5 mm from the outermost periphery to the inner periphery becomes a portion for holding the optical element in the lens barrel. The width of the edge surface a was 3 mm, and the width of the edge surface c was 4 mm.

While the optically effective surface R2 side of the base material 21 was attracted to and rotated by the suction rotating shaft of the coating device, the light shielding paint GT-7II (manufactured by Canon Kasei Co., Ltd.) was applied to each edge surface by a sponge coating method. After the entire edge surface is black and the film is sufficiently thick, GT-7II diluted with the same amount of thinner as the paint is applied to a width of about 2 mm from the outer peripheral side of the edge surface c. It was coated by a sponge coating method by stacking the layers. Next, after air-drying these for 1 hour, they were calcined at 80° C. for 2 hours.

The evaluation results are shown in Table 2.

(Comparative Example 4)
In Comparative Example 4, a sample was prepared in which the light-shielding paint GT-7II was applied in the same conditions and in the same process as in Example 6, and then the thinner-diluted paint was not repeatedly applied. Next, after air-drying these for 1 hour, they were calcined at 80° C. for 2 hours.

The evaluation results are shown in Table 2.

(Example 7)
In Example 7, the same optical element as in Example 1 was used. In the optical element of Example 7, an area of about 1.5 mm from the outermost periphery of the optical element to the inner peripheral part was in contact with the lens barrel at the attachment holding portion of the optical element in the lens barrel.

Coating of the light-shielding film was performed using a coating device equipped with two dispensers. First, as shown in FIG. 9, the optically effective surface side R2 of the base material 21 is attracted to the suction rotation shaft of the coating device, and the dispenser 11 is used while the optical element is rotated at an angle of 45 degrees with respect to the optical axis. A light shielding material GT-7II was discharged to coat the edge surface.

After coating the entire edge surface, as shown in FIG. 10, the position of the substrate 21 was adjusted so that the optical axis was vertical. While rotating the substrate 21, using the second dispenser 12, a light shielding material GT-7II diluted with the same amount of thinner was applied to the surface c perpendicular to the central axis of the optical element over a width of about 2 mm from the outer periphery. No. 2 paint 16 was applied in layers. FIG. 11 shows the optical element after such coating as viewed from the R1 side. In the figure, h3 corresponds to the position where GT-7II diluted with thinner was coated, and has a width of approximately 2 mm. rice field. By applying the thinner-diluted paint before the first applied paint GT-7II is completely dried, a light-shielding film structure having a gradation h2 between the two paints as shown in FIG. 8 is obtained. Next, after air-drying for 1 hour, firing was performed at 80° C. for 2 hours.

The evaluation results are shown in Table 3.

(Comparative Example 5)
In Comparative Example 5, unlike Example 7, a light shielding film was formed in the same manner as in Example 7 except that the light shielding film was not overcoated with diluted thinner.

In Comparative Example 5, GT-7II was applied to the entire edge surface under the same conditions and steps as in Example 7. After that, without coating the paint diluted with thinner on top, natural drying for 1 hour and baking at 80° C. for 2 hours were performed to prepare a sample for comparison.

The evaluation results are shown in Table 3.

(Comparative Example 6)
In Comparative Example 6, unlike Example 7, a light-shielding film was formed by top-coating GT-7II undiluted solution instead of thinner-diluted paint.

In Comparative Example 6, GT-7II was applied to the entire edge surface under the same conditions and steps as in Example 7. After that, as shown in FIG. 10, the position was adjusted so that the optical axis of the substrate 21 was vertical. Using the second dispenser 12 while rotating the base material 21, the same light-shielding material GT-7II that was previously applied was overlaid on the surface c perpendicular to the central axis of the optical element with a width of about 2 mm from the outer periphery. was applied. After air-drying for 1 hour, baking was performed at 80° C. for 2 hours.

The evaluation results are shown in Table 3.

(Example 8)
In Example 8, a meniscus-shaped substrate 31 shown in FIG. 12 was used. The radius of curvature of the effective optical surface R1 of the substrate 31 is 70.0 mm, and the radius of curvature of the effective optical surface R2 is 110 mm. The maximum perimeter of the effective optical surface R1 is φ50.0 mm, and the maximum perimeter of the effective optical surface R2 is φ80 mm. The edge surface 41 has a width of 15 mm, and about 5 mm from the outer peripheral portion of this width comes into contact with the lens barrel at the attachment holding portion of the optical element in the lens barrel.

In Example 8, the optically effective surface R2 side of the base material 31 is attracted to the suction rotary shaft of the coating device and rotated while the edge surface 41 faces upward, and the light shielding paint GT-20 (manufactured by Canon Kasei Co., Ltd.) is applied by a roll coating method. applied. At this time, the substrate 31 was applied while being rotated at 20 rpm. Next, while the fluidity of the paint was maintained, the optical element was rotated at 200 rpm for 20 seconds while maintaining that posture. Next, after air-drying this for 1 hour, it was calcined at 80° C. for 2 hours.

The evaluation results are shown in Table 4.

(Comparative Example 7)
In Comparative Example 7, unlike Example 8, an optical element was produced without rotating after coating.

In Comparative Example 7, GT-20 was applied to the entire edge surface under the same conditions and steps as in Example 8. Thereafter, without rotating the optical element, natural drying for 1 hour and baking at 80° C. for 2 hours were performed to prepare a sample for comparison.

The evaluation results are shown in Table 4.

(Comparative Example 8)
In Comparative Example 8, unlike Example 8, an optical element having a light-shielding film with a small difference in hardness was produced by changing the number of revolutions after coating.

In Comparative Example 8, GT-20 was applied to the entire edge surface under the same conditions and steps as in Example 8. After that, while the fluidity of the coating material was maintained, the optical element was rotated at a rotation speed of 80 rpm for 20 seconds in the same posture as when the optical element was coated. Next, natural drying for 1 hour and baking at 80° C. for 2 hours were performed to prepare a sample for comparison.

The evaluation results are shown in Table 4.

(Comparative Example 9)
In Comparative Example 9, unlike Example 8, an optical element was produced by changing the number of revolutions after coating.

In Comparative Example 9, GT-20 was applied to the entire edge surface under the same conditions and steps as in Example 8. After that, while the fluidity of the paint was maintained, the optical element was rotated at a rotation speed of 400 rpm for 20 seconds while maintaining the posture in which the optical element was applied. Next, natural drying for 1 hour and baking at 80° C. for 2 hours were performed to prepare a sample for comparison.

The evaluation results are shown in Table 4.

(Example 9)
In Example 9, an optical element having the same shape as the optical element used in Example 8 was coated with a light-shielding film using a dispenser. GT-20 (Canon Kasei Co., Ltd.) was used as the paint, and as in Example 4, the coating was performed with the edge surface 41 facing upward while the R2 surface of the coating device was attracted to the suction rotation shaft and rotated. While discharging about 10 nl of paint from the dispenser, the coating was applied while rotating the optical element at about 60 rpm so that the paint applied to the edge surface overlapped. Further, the coating was applied from the outer peripheral portion to the inner peripheral portion, and by adjusting the ejection frequency of the coating material, the overlapping amount of the applied coating material was kept substantially constant.

The optical element was then rotated at 180 rpm for 30 seconds while maintaining its position before the paint was sufficiently dried and lost its fluidity. Then, after air-drying for 1 hour, baking was performed at 80° C. for 2 hours. A schematic diagram of the optical element produced in Example 9 is shown in FIG.

The evaluation results are shown in Table 5.

(Comparative Example 10)
In Comparative Example 10, unlike Example 9, an optical element was produced without rotating after coating.

In Comparative Example 10, GT-20 was applied to the entire edge surface under the same conditions and steps as in Example 9. Thereafter, without rotating the optical element, natural drying for 1 hour and baking at 80° C. for 2 hours were performed to prepare a sample for comparison.

The evaluation results are shown in Table 5.

(Comparative Example 11)
In Comparative Example 11, unlike Example 9, an optical element was also produced in which the number of revolutions after coating was changed.

In Comparative Example 11, GT-20 was applied to the entire edge surface under the same conditions and steps as in Example 9. After that, while the fluidity of the paint was maintained, the optical element was rotated at a rotation speed of 60 rpm for 30 seconds while maintaining the posture when the optical element was applied. Next, natural drying for 1 hour and baking at 80° C. for 2 hours were performed to prepare a sample for comparison.

The evaluation results are shown in Table 5.

(Evaluation of Examples and Comparative Examples)
In Examples 1 to 9, as shown in Tables 1 to 5, the hardness of the light shielding film h3 on the air side and outer peripheral side of the light shielding film formed on the edge surface c perpendicular to the central axis L of the base material 21 is 4. The amount of eccentricity was small in the range of 0.5 GPa to 9.5 GPa. Further, it has been found that the difference in hardness between the portion h3 formed on the edge surface c that is in contact with the lens barrel and the portion h1 that is not in contact with the lens barrel is preferably 0.8 GPa or more. Thus, by using a light-shielding film having a hardness distribution on the surface in the direction perpendicular to the optical axis, the amount of eccentricity with respect to the optical axis can be reduced. In Comparative Examples 1 to 11, when the Vickers hardness of the portion of the light shielding film in contact with the lens barrel exceeded 9.5 GPa, or when the hardness distribution of the light shielding film was absent, the amount of eccentricity increased.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist. For example, the optical element of this embodiment is not limited to a lens, and may be a wavelength plate, a beam splitter, or the like as long as it is a member that transmits light. Further, the optical equipment is not limited to cameras, and can be widely applied to optical equipment such as microscopes and projectors.

The optical element can be applied to optical equipment such as cameras, microscopes, and projectors.

REFERENCE SIGNS LIST 1 optical device 2 lens barrel 3 optical element 4 light shielding film 5 substrate 21 substrate 31 meniscus substrate 41 edge surface of meniscus substrate a first edge surface perpendicular to the optical axis b parallel to the optical axis Inner peripheral edge surface c Second edge surface perpendicular to the optical axis d Outer peripheral edge surface parallel to the optical axis f1 Light-shielding film formed on the inner peripheral side of the second edge surface perpendicular to the optical axis f2 Light Light shielding film h1 formed on the outer peripheral surface of the second edge surface perpendicular to the axis Light shielding film formed on the inner peripheral side of the second edge surface perpendicular to the optical axis L Optical axis

Claims (15)

an optical element;
and a lens barrel that holds the optical element therein,
The optical element is
a substrate having an optically effective surface and a non-optically effective surface;
a light shielding film provided on at least part of the non-optically effective surface of the base;
has
the light shielding film has a first portion and a second portion , the first portion having a lower hardness than the second portion;
The optical element is in contact with the lens barrel at the first portion ,
at least a portion of the second portion is located between the non-optically effective surface of the substrate and the first portion;
An optical instrument characterized by: an optical element;
and a lens barrel that holds the optical element therein,
The optical element is
a substrate having an optically effective surface and a non-optically effective surface;
a light shielding film provided on at least part of the non-optically effective surface of the base;
has
the light shielding film has a first portion and a second portion, the first portion having a lower hardness than the second portion;
The optical element is in contact with the lens barrel at the first portion,
The first portion and the second portion are provided adjacent to each other in a direction perpendicular to the optical axis on a surface perpendicular to the optical axis of the optical element among the non-optically effective surfaces. ,
An optical instrument, wherein the second portion is closer to the optical axis than the first portion . an optical element;
and a lens barrel that holds the optical element therein,
The optical element is
a substrate having an optically effective surface and a non-optically effective surface;
a light shielding film provided on at least part of the non-optically effective surface of the base;
has
the light shielding film has a first portion and a second portion, the first portion having a lower hardness than the second portion;
The optical element is in contact with the lens barrel at the first portion,
The optical device, wherein the first portion has a Vickers hardness of 4.5 GPa or more and 9.5 GPa or less. an optical element;
and a lens barrel that holds the optical element therein,
The optical element is
a substrate having an optically effective surface and a non-optically effective surface;
a light shielding film provided on at least part of the non-optically effective surface of the base;
has
the light shielding film has a first portion and a second portion, the first portion having a lower hardness than the second portion;
The optical element is in contact with the lens barrel at the first portion,
4. The optical instrument according to claim 1, wherein the first portion has a Vickers hardness lower than that of the second portion by 0.8 GPa or more. The Vickers hardness of the first portion is 4.5 GPa or more and 9.5 GPa or less, and the Vickers hardness of the first portion is lower than that of the second portion by 0.8 GPa or more. 3. The optical instrument according to claim 1 or 2 . 6. A portion of the non-optically effective surface is positioned between the first portion and the optical axis in a direction perpendicular to the optical axis of the optical element. or the optical instrument according to item 1 . 7. The optical device according to claim 1 , wherein the light shielding film has an average film thickness of 3 μm or more and 50 μm or less. 8. The optical device according to any one of claims 1 to 7 , wherein the substrate comprises glass or resin. 9. The optical apparatus according to any one of claims 1 to 8 , wherein the lens barrel comprises metal or resin. a substrate having an optically effective surface and a non-optically effective surface ;
and a light shielding film provided on at least part of the non-optically effective surface of the base material,
The light shielding film has a first portion arranged to be in contact with the lens barrel holding the optical element inside , and a second portion , and the first portion is the second portion. lower hardness,
An optical element , wherein at least part of the second portion is between the non-optically effective surface of the substrate and the first portion. a substrate having an optically effective surface and a non-optically effective surface;
and a light shielding film provided on at least part of the non-optically effective surface of the base material,
The light shielding film has a first portion arranged to be in contact with the lens barrel holding the optical element inside, and a second portion, and the first portion is the second portion. lower hardness,
The first portion and the second portion are provided adjacent to each other in a direction perpendicular to the optical axis on a surface perpendicular to the optical axis of the optical element among the non-optically effective surfaces. ,
The optical element, wherein the second portion is closer to the optical axis than the first portion . a substrate having an optically effective surface and a non-optically effective surface;
and a light shielding film provided on at least part of the non-optically effective surface of the base material,
The light shielding film has a first portion arranged to be in contact with the lens barrel holding the optical element inside, and a second portion, and the first portion is the second portion. lower hardness,
The optical element, wherein the first portion has a Vickers hardness of 4.5 GPa or more and 9.5 GPa or less. a substrate having an optically effective surface and a non-optically effective surface;
and a light shielding film provided on at least part of the non-optically effective surface of the base material,
The light shielding film has a first portion arranged to be in contact with the lens barrel holding the optical element inside, and a second portion, and the first portion is the second portion. lower hardness,
The optical element, wherein the Vickers hardness of the first portion is lower than that of the second portion by 0.8 GPa or more. 14. The optical element according to any one of claims 10 to 13 , wherein the light shielding film has an average film thickness of 3 µm or more and 50 µm or less. 15. The optical element according to any one of claims 10 to 14 , wherein the substrate comprises glass or resin.

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