JP2012002888A - Optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member that prevents cement used for a cemented lens from dissolving to deteriorate optical performance when forming an optical thin film by a wet type film formation method.SOLUTION: An optical member 1 includes: a cemented lens 5 composed by cementing two lenses; an optical thin film 15 formed on a lens surface 6a that is the outer surface side of a convex lens 6 located at one end of the cemented lens 5 by a wet type film formation method; and a holding member 10 that is attached so as to hold the cemented lens 5 by being joined with the periphery of a concave lens 7 located at the other end of the cemented lens 5 and is integrally used with the cemented lens 5. The holding member 10 is cylindrically formed so as to surround the periphery of the concave lens 7. A boundary 8 between the concave lens 7 and the convex lens 6 on the outer peripheral surface of the cemented lens 5 is exposed outside.

Description

  The present invention relates to an optical member coated with an optical thin film such as an antireflection film.

  In general, the surface of each lens constituting an optical system such as a camera lens or a microscope objective lens is coated (applied) with an antireflection film in order to reduce light reflection. Such an optical thin film is formed on the surface of the lens using, for example, a wet film forming method. In the wet film formation method, an optical thin film can be formed using the property that the coating liquid flows following the curved surface of the lens, and therefore an optical thin film having a uniform film thickness can be formed relatively easily. Among these wet film forming methods, the spin coating method forms a thin and uniform optical thin film by spreading the coating solution applied to the lens thinly and uniformly by the centrifugal force of rotation. It is possible.

  However, when an optical thin film is formed using the spin coating method, depending on the shape of the lens, the applied coating liquid may wrap around the surface opposite to the application surface (back surface), especially when the lens is suction chucked, In some cases, the coating liquid is sucked from the gap between the lens fixing jig and the lens, and the back surface of the lens is stained. Accordingly, an optical member including a lens, a holding member that is attached and integrated so as to hold the lens, and an optical thin film formed on the surface of the lens and the holding member has been proposed (for example, Patent Documents). 1). According to such an optical member, since the holding member is integrally attached to the lens, when forming the optical thin film using the spin coating method, an excess coating liquid flows to the end of the holding member by rotation. After that, the coating liquid scatters around, so that it is possible to prevent the coating liquid from flowing around the lens back surface and becoming dirty.

International Publication No. 2008/062817 Pamphlet

  When a cemented lens is used in such an optical member, the coating liquid may contain a component that dissolves the binder used in the cemented lens. Therefore, when an optical thin film is formed by a wet film formation method, the cemented lens is configured. If the coating solution is brought into contact with the boundary portion of each lens for a long time without being cured, the bonding agent used in the cemented lens may be dissolved to deteriorate the optical performance.

  The present invention has been made in view of such problems, and prevents the optical performance from being deteriorated due to the dissolution of the bonding agent used in the cemented lens when forming an optical thin film by a wet film forming method. An object of the present invention is to provide an optical member.

  In order to achieve such an object, an optical member according to a first aspect of the present invention is provided on a lens surface on the outer surface side of a cemented lens configured by cementing a plurality of lenses and one end side lens located at one end of the cemented lens. An optical thin film formed by a wet film formation method and an outer peripheral portion of the other end side lens located at the other end of the cemented lens are attached so as to hold the cemented lens, and integrated with the cemented lens A holding member to be used, and the holding member is formed in a cylindrical shape surrounding the outer peripheral portion of the other end side lens, and is adjacent to the other end side lens and the other end side lens on the outer peripheral surface of the cemented lens. The boundary with the lens is exposed to the outside.

  In the above-described optical member, it is preferable that the end portion of the holding member facing the one end side of the cemented lens is positioned on the other end side of the cemented lens with respect to the boundary portion.

  The optical member according to the second invention is formed by a wet film-forming method on a cemented lens configured by cementing a plurality of lenses and an outer lens surface of the one-end lens located at one end of the cemented lens. An optical thin film, and a holding member that is attached to the outer peripheral portion of the one end side lens so as to hold the cemented lens and is used integrally with the cemented lens. It is formed in a cylindrical shape surrounding the outer peripheral portion of the side lens, and a boundary portion between the one end side lens and the lens adjacent to the one end side lens on the outer peripheral surface of the cemented lens is exposed to the outside.

  In the above-described optical member, the end of the holding member facing the other end of the cemented lens is positioned closer to one end of the cemented lens than the boundary, and the inner periphery of the end of the holding member It is preferable that a taper surface is formed in the portion, and an adhesive that bonds the one end side lens and the holding member is applied across the outer peripheral surface of the one end side lens and the tapered surface.

  In the optical member described above, it is preferable that the holding member is a diaphragm member.

Further, in the above-described optical member, when the diameter of the one end side lens is D and the radius of curvature of the lens surface on the outer surface side of the one end side lens is R, the following formula 0.9 ≦ D / R ≦ 2.0
It is preferable to satisfy the following conditions.

  According to the present invention, when an optical thin film is formed by a wet film formation method, it is possible to prevent the bonding agent used for the cemented lens from being dissolved and the optical performance from being deteriorated.

It is sectional drawing which shows the optical member of 1st Embodiment. It is an enlarged view which shows the vicinity of the taper surface in the optical member of 1st Embodiment. It is sectional drawing which shows the optical member of 2nd Embodiment. It is sectional drawing which shows the optical member of 3rd Embodiment. It is an enlarged view which shows the vicinity of the taper surface in the optical member of 3rd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. An optical member according to the first embodiment is shown in FIG. 1. This optical member 1 includes a cemented lens 5 configured by cementing two lenses, and a holding member attached so as to hold the cemented lens 5. 10 and an optical thin film 15 formed on the lens surface of the cemented lens 5. The cemented lens 5 includes a convex lens 6 positioned on one end side of the cemented lens 5 and a concave lens 7 positioned on the other end side of the cemented lens 5, and the convex lens 6 and the concave lens 7 have a predetermined cementing agent. Are joined together.

  An optical thin film 15 is formed on the lens surface 6a on the outer surface side (one end side) of the convex lens 6 by a wet film forming method. The optical thin film 15 is, for example, an antireflection film. In the present embodiment, when the diameter of the convex lens 6 is D and the radius of curvature of the lens surface 6a on the outer surface side of the convex lens 6 is R, the condition represented by the following conditional expression (1) may be satisfied. preferable.

  0.9 ≦ D / R ≦ 2.0 (1)

  The holding member 10 is formed in a cylindrical shape surrounding the outer peripheral portion of the concave lens 7, and a lens housing portion 11 that fits the concave lens 7 is formed on the inner peripheral portion on one end side of the holding member 10. As shown in FIG. 2, a tapered surface 13 is formed on the inner peripheral portion of the end surface 12 of the holding member 10 facing the one end side of the cemented lens 5, and is fitted to the lens housing portion 11 from one end side of the holding member 10. An adhesive 17 that bonds the concave lens 7 and the holding member 10 is applied across the outer peripheral surface of the concave lens 7 and the tapered surface 13. As a result, the holding member 10 is attached to the outer peripheral portion of the concave lens 7 so as to hold the cemented lens 5 and is used integrally with the cemented lens 5.

  As shown in FIGS. 1 and 2, a boundary portion 8 between the concave lens 7 and the convex lens 6 adjacent to the concave lens 7 on the outer peripheral surface 5 a of the cemented lens 5 is exposed to the outside. That is, the end surface 12 of the holding member 10 facing the one end side of the cemented lens 5 is formed in a ring-shaped plane, and is positioned on the other end side of the cemented lens 5 with respect to the boundary portion 8 between the concave lens 7 and the convex lens 6. is doing. Note that the end surface 12 on one end side of the holding member 10 is located at a distance of 0.5 mm or more (in the direction along the central axis) on the other end side of the cemented lens 5 with respect to the boundary portion 8 between the concave lens 7 and the convex lens 6. It is preferable.

  In the optical member 1 configured as described above, for example, when the optical thin film 15 is formed by a spin coating method which is a wet film forming method, the holding member 10 coupled to the cemented lens 5 (concave lens 7) is not illustrated. While being attached to the support portion of the coater, the cemented lens 5 and the holding member 10 are rotated around the central axis while dropping the coating liquid onto the lens surface 6a (near the center) on the outer surface side of the convex lens 6. Then, due to the centrifugal force due to rotation, the coating liquid flows on the lens surface 6a of the convex lens 6 (and the outer peripheral surface 5a of the cemented lens 5), and the excess coating liquid flows on the end surface 12 on one end side of the holding member 10 Spatter from the outer periphery to the surroundings. Thereby, the applied coating liquid can be prevented from wrapping around the surface (back surface) opposite to the lens surface 6 a (application surface) of the convex lens 6, and the coating liquid can be prevented from accumulating at the edge of the cemented lens 5. Thus, the optical thin film 15 having high film thickness uniformity can be formed.

  Further, since the boundary portion 8 between the concave lens 7 and the convex lens 6 is exposed to the outside, the coating liquid does not accumulate in the vicinity of the boundary portion 8, and the boundary portion 8 contacts the boundary portion 8 for a long time without being cured. Therefore, it is possible to prevent the bonding agent used in the cemented lens 5 from being dissolved and the optical performance from being deteriorated. As described above, according to the first embodiment, when the optical thin film 15 is formed by the wet film forming method, it is possible to prevent the bonding agent used in the cemented lens 5 from being dissolved and the optical performance from being deteriorated. it can.

  The end surface 12 of the holding member 10 facing one end side of the cemented lens 5 is positioned on the other end side of the cemented lens 5 with respect to the boundary portion 8 between the concave lens 7 and the convex lens 6, so that the coating liquid is present in the vicinity of the boundary portion 8. Since it is more difficult to accumulate, it is possible to reliably prevent the bonding agent used in the cemented lens 5 from being dissolved and the optical performance from being deteriorated.

  Further, if the optical thin film 15 is formed on the lens surface 6a satisfying the condition expressed by the conditional expression (1), that is, the lens surface of a hemispherical lens or a lens close thereto, the film thickness uniformity. Higher effect can be obtained.

  Next, a second embodiment of the optical member will be described. As shown in FIG. 3, the optical member 21 according to the second embodiment includes a cemented lens 25 configured by cementing two lenses, a holding member 30 attached to hold the cemented lens 25, and a cemented lens. And an optical thin film 35 formed on the lens surface of the lens 25. The cemented lens 25 includes a concave lens 26 positioned on one end side of the cemented lens 25 and a convex lens 27 positioned on the other end side of the cemented lens 25. The concave lens 26 and the convex lens 27 are made of a predetermined cement. Are joined together. An optical thin film 35 similar to that of the first embodiment is formed on the lens surface 26a on the outer surface side (one end side) of the concave lens 26.

  The holding member 30 is formed in a cylindrical shape that surrounds the outer peripheral portion of the convex lens 27, and a lens housing portion 31 that fits the convex lens 27 is formed on the inner peripheral portion on one end side of the holding member 30. Although not shown in detail, a tapered surface (not shown) is formed on the inner peripheral portion of the end surface 32 of the holding member 30 facing the one end side of the cemented lens 25 as in the case of the first embodiment, and the holding member An adhesive (not shown) for bonding the convex lens 27 and the holding member 30 is applied from one end side of 30 to the outer peripheral surface and the tapered surface of the convex lens 27 fitted to the lens housing portion 31. As a result, the holding member 30 is attached to the outer peripheral portion of the convex lens 27 so as to hold the cemented lens 25 and is used integrally with the cemented lens 25.

  Further, a boundary portion 28 between the convex lens 27 and the concave lens 26 adjacent to the convex lens 27 on the outer peripheral surface 25a of the cemented lens 25 is exposed to the outside. That is, the end surface 32 of the holding member 30 facing one end side of the cemented lens 25 is formed in a ring-shaped plane, and is positioned on the other end side of the cemented lens 25 with respect to the boundary portion 28 between the convex lens 27 and the concave lens 26. is doing.

  In the optical member 21 configured as described above, for example, when the optical thin film 35 is formed by the spin coating method which is a wet film forming method, the holding member 30 coupled to the cemented lens 25 (convex lens 27) is not illustrated. While being attached to the support portion of the coater, the cemented lens 25 and the holding member 30 are rotated around the central axis while dropping the coating liquid onto the lens surface 26a (near the center) on the outer surface side of the concave lens 26. Then, as in the case of the first embodiment, the applied coating liquid can be prevented from wrapping around the surface (back surface) opposite to the lens surface 26a (application surface) of the concave lens 26, and at the edge of the cemented lens 25. Accumulation of the coating liquid can be prevented, and the optical thin film 35 with high film thickness uniformity can be formed.

  As in the case of the first embodiment, the boundary portion 28 between the convex lens 27 and the concave lens 26 is exposed to the outside. Therefore, according to the second embodiment, the same effect as that of the first embodiment can be obtained.

  Next, a third embodiment of the optical member will be described. As shown in FIG. 4, the optical member 41 of the third embodiment includes a cemented lens 45 configured by cementing two lenses, a holding member 50 attached to hold the cemented lens 45, and a cemented lens. And an optical thin film 55 formed on the lens surface of the lens 45. The cemented lens 45 includes a convex lens 46 positioned on one end side of the cemented lens 45 and a concave lens 47 positioned on the other end side of the cemented lens 45, and the convex lens 46 and the concave lens 47 have a predetermined cementing agent. Are joined together.

  An optical thin film 55 similar to that of the first embodiment is formed on the lens surface 46 a on the outer surface side (one end side) of the convex lens 46. In the present embodiment, when the diameter of the convex lens 46 is D and the radius of curvature of the lens surface 46a on the outer surface side of the convex lens 46 is R, the condition represented by the conditional expression (1) is satisfied. preferable.

  The holding member 50 is formed in a cylindrical shape that surrounds the outer peripheral portion of the convex lens 46, and a lens housing portion 51 that fits the convex lens 46 is formed on the inner peripheral portion on the other end side of the holding member 50. As shown in FIG. 5, a tapered surface 53 is formed on the inner peripheral portion of the end surface 54 of the holding member 50 facing the other end side of the cemented lens 45, and the lens housing portion 51 is fitted from the other end side of the holding member 50. An adhesive 57 that bonds the convex lens 46 and the holding member 50 is applied across the outer peripheral surface of the combined convex lens 46 and the tapered surface 53. Accordingly, the holding member 50 is attached to the outer peripheral portion of the convex lens 46 so as to hold the cemented lens 45 and is used integrally with the cemented lens 45. The inner peripheral surface 50a on one end side of the holding member 50 is formed in a conical shape having a maximum diameter on one end side.

  Further, as shown in FIGS. 4 and 5, a boundary portion 48 between the convex lens 46 and the concave lens 47 adjacent to the convex lens 46 is exposed to the outside on the outer peripheral surface 45 a of the cemented lens 45. That is, the end surface 54 of the holding member 50 facing the other end side of the cemented lens 45 is formed in a ring-shaped plane and is positioned closer to one end side of the cemented lens 45 than the boundary portion 48 between the convex lens 46 and the concave lens 47. is doing.

  In the optical member 41 configured as described above, for example, when the optical thin film 55 is formed by a spin coating method that is a wet film forming method, the holding member 50 coupled to the cemented lens 45 (convex lens 46) is not illustrated. While being attached to the support portion of the coater, the cemented lens 45 and the holding member 50 are rotated around the central axis while dropping the coating liquid onto the lens surface 46a (near the center) on the outer surface side of the convex lens 46. Then, the coating liquid flows on the lens surface 46a of the convex lens 46 due to the centrifugal force caused by the rotation, and the excess coating liquid flows on the inner peripheral surface 50a and the end surface 52 on one end side of the holding member 50 and from the outer peripheral portion to the periphery. Scatter. Thereby, the applied coating liquid can be prevented from wrapping around the surface (back surface) opposite to the lens surface 46 a (application surface) of the convex lens 46, and the coating liquid can be prevented from accumulating at the edge of the cemented lens 45. Thus, the optical thin film 55 with high film thickness uniformity can be formed.

  In addition, since the boundary portion 48 between the convex lens 46 and the concave lens 47 is exposed to the outside, the coating liquid does not accumulate in the vicinity of the boundary portion 48 and contacts the boundary portion 48 for a long time without being cured. Therefore, it is possible to prevent the bonding agent used for the cemented lens 45 from being dissolved and the optical performance from being deteriorated. Thus, according to the third embodiment, when the optical thin film 55 is formed by the wet film forming method, it is possible to prevent the bonding agent used for the cemented lens 45 from being dissolved and the optical performance from being deteriorated. it can.

  In the third embodiment, the end surface 54 of the holding member 50 facing the other end side of the cemented lens 45 is located on one end side of the cemented lens 45 with respect to the boundary portion 48 between the convex lens 46 and the concave lens 47. The adhesive 57 that bonds the convex lens 46 and the holding member 50 is applied across the outer peripheral surface of the lens and the tapered surface 53 of the holding member 50. Thereby, even if the coating liquid flows into the gap between the convex lens 46 and the holding member 50, it is possible to prevent the coating liquid from flowing to the other end side of the cemented lens 45 at the portion where the adhesive 57 is applied. Since the coating liquid is less likely to accumulate in the vicinity of the boundary portion 48, it is possible to reliably prevent the bonding agent used in the cemented lens 45 from being dissolved and the optical performance from being deteriorated.

  Further, if the optical thin film 55 is formed on the lens surface 46a satisfying the condition expressed by the conditional expression (1), that is, the lens surface of the hemispherical lens or a lens close thereto, the film thickness uniformity. Higher effect can be obtained.

  In the third embodiment described above, when the optical member 41 is incorporated in an optical device (not shown) or the like, the holding member 50 may function as a diaphragm member such as an aperture diaphragm. If it does in this way, in an optical device etc. in which optical member 41 is incorporated, the number of parts can be reduced.

  In each of the above-described embodiments, the cemented lens is configured by cementing two lenses (doublets). However, the present invention is not limited to this, and for example, by cementing three lenses (triplets). You may make it comprise, and it should just be comprised by joining a some lens.

  In each of the embodiments described above, the optical thin film is formed by spin coating. However, the present invention is not limited to this. For example, the optical thin film may be formed by dip coating, or wet film formation. An optical thin film may be formed by a method.

1 Optical member (first embodiment)
5 cemented lens 6 convex lens (lens on one end) 7 concave lens (lens on the other end)
8 boundary part 10 holding member 12 end face on one end side 15 optical thin film 21 optical member (second embodiment)
25 cemented lens 25
26 Concave lens (lens on one end) 27 Convex lens (lens on the other end)
28 boundary part 30 holding member 32 end face on one end side 35 optical thin film 41 optical member (third embodiment)
45 cemented lens 46 convex lens (lens on one end) 47 concave lens (lens on the other end)
48 boundary portion 50 holding member 53 taper surface 54 end surface on the other end side 55 optical thin film 57 adhesive

Claims (6)

A cemented lens formed by cementing a plurality of lenses;
An optical thin film formed by a wet film formation method on the lens surface on the outer surface side of the one end side lens located at one end of the cemented lens;
A holding member that is attached to an outer peripheral portion of the other end side lens located at the other end of the cemented lens and is attached to hold the cemented lens, and is used integrally with the cemented lens;
The holding member is formed in a cylindrical shape surrounding the outer peripheral portion of the other end side lens,
An optical member, wherein a boundary portion between the other end side lens and a lens adjacent to the other end side lens on the outer peripheral surface of the cemented lens is exposed to the outside.   2. The optical member according to claim 1, wherein an end portion of the holding member facing the one end side of the cemented lens is positioned on the other end side of the cemented lens with respect to the boundary portion. A cemented lens formed by cementing a plurality of lenses;
An optical thin film formed by a wet film formation method on the lens surface on the outer surface side of the one end side lens located at one end of the cemented lens;
A holding member that is attached to the outer peripheral portion of the one end side lens and is attached to hold the cemented lens, and is used integrally with the cemented lens;
The holding member is formed in a cylindrical shape surrounding the outer peripheral portion of the one end side lens,
An optical member, wherein a boundary portion between the one end side lens and the lens adjacent to the one end side lens on the outer peripheral surface of the cemented lens is exposed to the outside. The end of the holding member facing the other end of the cemented lens is located on one end of the cemented lens with respect to the boundary,
A tapered surface is formed on the inner peripheral portion of the end portion of the holding member,
The optical member according to claim 3, wherein an adhesive that bonds the one end side lens and the holding member is applied across an outer peripheral surface of the one end side lens and the tapered surface.   The optical member according to claim 3 or 4, wherein the holding member is a diaphragm member. When the diameter of the one end side lens is D and the radius of curvature of the lens surface on the outer surface side of the one end side lens is R, the following expression 0.9 ≦ D / R ≦ 2.0
The optical member according to claim 1, wherein the following condition is satisfied.

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