JPH10186108A - Composite optical element and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent resin from being overflowed from a base material even when the feeding amount of resin is uneven, to remove the deterioration of optical performance such as ghost and flare and to compact each product. SOLUTION: In an optical element base material 2 for the composite optical element, an outside part from the optically effective diameter D of a face 2a on which a resin layer is to be formed has a shape obtained by removing a part 2d of the material 2 so that the volume of the material 2 is reduced from a shape obtained by extending the radius of curvature in the optically effective diameter D of the face 2a. At least a part for forming a resin layer on it out of a face 2b exposed after removing a part 2d of the material 2 is formed as a mirror and at the time of forming the resin layer, resin overflowed the face 2a is received by the face 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a composite optical element in which a resin layer is mounted on an optical element substrate and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Application Laid-Open No. 5-3379
There is a technique described in JP-A-59-59. Generally, when manufacturing a composite optical element, the amount of resin supplied is slightly increased so that no gap is formed between the mold and the resin layer formed by the base material, and the resin protruding from the base material is wiped off. However, this wiping operation is poor in workability and has a problem in mass productivity. For this reason, the technology disclosed in Japanese Patent Application Laid-Open No. Hei 5-337959 discloses a technique in which a resin pool is formed outside the optically effective diameter of a mold or a substrate so as to widen a space formed by the mold and the substrate when manufacturing a composite optical element. And the resin is allowed to flow into the resin reservoir. For this reason, even if the supply amount of the resin varies, the resin does not protrude from the base material, and the work of wiping the resin is not required, so that a large number of composite optical elements can be manufactured continuously.

[0003]

However, the prior art has the following disadvantages. Since the portion of the base material outside the effective diameter is formed by centering, even when a resin reservoir is provided on the base, it is common to integrally work by centering. In other words, the surface state of the resin pool portion of the base material is not a mirror surface such as a polished surface, but a surface having a poor light transmittance. However, even though the pick-up surface is out of the effective optical diameter, if light is irregularly reflected on the pick-up surface, the influence extends not only outside the optical effective diameter but also into the optical effective diameter. Therefore, there is a problem that optical performance such as ghost and flare is deteriorated.

In the case where the resin pool is provided in the mold, the optical performance is not deteriorated because irregular light reflection or the like does not occur. However, the resin flowing into the portion where the resin pool is provided becomes a projection, and the manufactured composite mold is formed. The thickness of the optical element in the optical axis direction increases.
Therefore, it leads to a problem of hindering product downsizing.

The present invention has been made in view of the above-mentioned problems of the prior art. Even if there is a variation in the amount of supplied resin, the resin does not protrude from the base material and the optical performance such as ghost and flare is not improved. It is an object of the present invention to provide a composite optical element which can be made compact without deterioration and a method for manufacturing the same.

[0006]

To achieve the above object, a composite optical element according to a first aspect of the present invention is a composite optical element in which an energy-curable resin layer is mounted on the surface of an optical element substrate. In the optical element substrate, the volume of the substrate decreases with respect to a shape in which the outside of the optical effective diameter of the surface on which the resin layer is mounted has an extended radius of curvature within the optical effective diameter of the surface. As described above, the base material has a shape in which a part of the base material is removed, and at least a part on which the resin layer is placed on the surface exposed after removing the part of the base material is a mirror surface.

In the method for manufacturing a composite optical element according to a second aspect of the present invention, an energy-curable resin is supplied to the surface of the optical element substrate, and the substrate and the mold are relatively brought close to each other. After forming the desired resin layer between the mold and the base material by spreading the resin by, the resin layer is cured by irradiation of energy, and the cured resin layer and the mold are separated to form the desired resin layer. In the method of manufacturing a composite optical element for manufacturing a composite optical element having, the outer side of the optical effective diameter of the surface on which the resin layer is mounted is a shape in which the radius of curvature within the optical effective diameter of the surface is extended. The shape of the base material is partially removed so that the volume of the base material is reduced, and at least the portion on which the resin layer is placed on the surface exposed after removing the part of the base material is a mirror surface. It is characterized by using an optical element substrate.

That is, in the optical element substrate of the composite optical element according to the first invention, the radius of curvature within the optical effective diameter of the surface outside the optical effective diameter of the surface on which the resin layer is mounted is set. A part of the base material is removed so that the volume of the base material is reduced with respect to the extended shape, and at least a resin layer on a surface exposed after removing the part of the base material is placed. The part is mirrored.

Further, in the method for manufacturing a composite optical element according to the second invention, the outer side of the optical effective diameter of the surface on which the resin layer is mounted has a shape in which the radius of curvature within the optical effective diameter of the surface is extended. The base material has a shape in which a part of the base material is removed so that the volume of the base material is reduced, and at least a part on which a resin layer is placed on a surface exposed after removing the part of the base material is a mirror surface. The resin is supplied onto the surface of the optical element substrate that is
After forming the desired resin layer by spreading the resin by relatively approaching the optical element substrate and the mold, the resin layer is cured by irradiation with energy, and the cured resin layer and the mold are separated. Thus, a composite optical element having a desired resin layer is manufactured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A composite optical element and a method for manufacturing the same according to the present invention will be described with reference to FIG. As shown in FIG. 1, the substrate 2 has an optical effective diameter D of a surface 2a on which the resin layer is placed.
The outer side is a shape different from the shape obtained by directly extending the radius of curvature within the optical effective diameter D on the surface 2a side on which the resin layer is mounted. Here, the outer edge portion of the base material 2 is removed in a direction perpendicular to the central axis O of the base material 2 (a chain line portion 2 shown in the drawing).
d is removed) to form the plane 2b. Therefore, the volume of the substrate 2 is a shape obtained by directly extending the radius of curvature within the optical effective diameter D of the substrate 2 (the shape of the substrate 2 including the chain line portion 2d).
On the contrary. That is, even if the amount of the resin supplied to the surface 2a of the substrate 2 varies, the variation can be absorbed outside the optical effective diameter D, and the resin can be prevented from protruding from the substrate 2. it can. In addition, since the shape of the resin pressing surface (optical surface) 1a of the mold is not changed when expanding the space for absorbing the variation in the resin supply amount, the volume of the composite optical element itself does not increase. Absent. Therefore, there is no hindrance to the downsizing of the product.

Further, in the composite optical element and the method of manufacturing the same according to the present invention, as shown in FIG. 1, the shape of the surface of the substrate 2 on which the resin layer is placed is changed outside the optical effective diameter D, The surface exposed after the shape change, that is, the flat surface 2b is finished to a surface such as a mirror surface through which light beams are regularly transmitted. Accordingly, on the surface exposed after the shape change, that is, on the plane 2b, irregular reflection of light does not occur, and no ghost or flare that leads to deterioration of optical performance occurs within the optical effective diameter D.

[First Embodiment of the Invention] A first embodiment of the present invention will be described with reference to FIGS. 2 and 3
FIG. 4 is a view showing an optical element substrate of a composite optical element, and FIGS.
FIG. 3 is a diagram showing a manufacturing process of the composite optical element.

In the first embodiment of the present invention, as shown in FIG. 2, a glass substrate 12 having concave surfaces formed on both sides is used as an optical element substrate, and an ultraviolet curable resin as an energy curable resin is used on one surface. A composite optical element is formed by curing a resin layer made of resin (hereinafter, referred to as resin) 15. The base material 12 has a diameter R of 25 mm and an optical effective diameter D of 19.5.
Polished surface on which a resin layer having a concave surface with a radius of curvature of 15 mm up to a diameter of 20 mm is placed (hereinafter referred to as a molding surface).
12a is formed on one surface (the upper surface in the figure) and has a diameter of 20
A plane 12b perpendicular to the center axis O of the base material 12 is formed outside (outer edge) of the base 12b. This plane 12b
As shown in FIG. 3, is formed by removing a dashed line portion 12d which is a shape portion obtained by extending the radius of curvature of the molding surface 12a to the outer peripheral portion of the base material 12.
2 has a reduced volume. That is, as compared with the case where the molding surface 12a is formed up to the diameter R of the base material 12, the space for filling the resin 15 outside the optically effective diameter D is increased by the volume reduction of the base material 12, so that the flat surface 12b Up to 15 resin
Can be widened, which is advantageous for the variation in the resin supply amount. The flat surface 12b has a roughness Ra =
It is mirror-finished to 0.020 μm and has a flat surface 12b
When the substrate 12 is observed between the light source and the observer, the shape of the light source cannot be recognized as in the case of a pick-up surface, but is at a level at which the shape of the light source can be clearly recognized. . Therefore, the resin layer 13 of the substrate 12 (FIGS.
Molding surface 12a and flat surface 12b on which the
Are transmitted through the molding surface 12 within the optical effective diameter D.
In addition to a, irregular reflection does not occur on the plane 12b.

On the other hand, the opposite surface (lower surface in the figure) of the molding surface 12a of the substrate 12 is a concave non-molding surface (surface on which the resin layer 13 is not placed) 12c, and is formed up to the outer peripheral portion of the substrate 12. The polished surface has a radius of curvature of 100 mm, and the thickness of the substrate 12 on the central axis O is 3 mm. The base material 12 has been previously subjected to a treatment for improving the adhesion between the base material 12 and the resin layer 13 by a known method using a silane coupling agent. Further, the supply amount of the resin 15 supplied on the molding surface 12a is such that the outermost peripheral portion of the resin layer 13 reaches the optical effective diameter D or more even if the supply amount varies, and It is set in advance so as not to protrude from the outer peripheral portion.

Next, a method of manufacturing a composite optical element will be described with reference to FIG. 2 and FIGS. To manufacture the composite optical element, the surface 13 of the desired resin layer 13 as shown in FIG.
a having an optical surface 11a for forming a
A mold 11 is used which has the same central axis as the central axis O of the base material 2 and is vertically movable.

First, as shown in FIG. 2, a required amount of the resin 15 is supplied onto the molding surface 12a of the base material 12 (the previously set amount). Next, the mold 11 is moved down to
, And the resin 15 on the molding surface 12a is pushed outward by the optical surface 11a of the mold 11 in the outer peripheral direction. Then, as shown in FIG. 4, the resin 15 spread between the molding surface 12a of the base material 12 and the optical surface 11a of the mold 11 forms the resin 11 at a position where the resin layer 13 having a desired thickness is formed. Stop descending. At this time, the shape of the resin layer 13 is such that the thickness on the central axis O is 0.1 mm and the radius of curvature of the surface 13a is 13 m.
m, and the optical effective diameter D is 19.5 mm. The outermost peripheral portion of the resin layer 13 reaches the outside of the molding surface 12a of the base material 12 and is on the plane 12b of the base material 12. That is, since the shape of the substrate 12 outside the optical effective diameter D is changed so as to widen the space formed by the substrate 12 and the mold 11, the resin 15 protrudes beyond the diameter R of the substrate 12. There is no.

Next, ultraviolet rays are applied to the entire surface of the resin layer 13 from below the base material 12 by ultraviolet irradiation means (not shown) to start curing of the resin layer 13. As a result, when the energy irradiation is completed, a close contact body in which the mold 11, the base material 12, and the cured resin layer 13 are integrated is formed.

Thereafter, when the contact body is raised, FIG.
As shown in (2), the tip of the peeling member 14 previously provided above a part of the plane 12b of the substrate 12 comes into surface contact with the plane 12b of the substrate 12. Here, the lower portion of the peeling member 14 that comes into contact with the flat surface 12b is formed on a flat surface 14a parallel to the flat surface 12b of the base material 12. And the base material 12
The load is first concentrated on a portion of the peeling member 14 on the flat surface 12a where the flat surface 14a is in contact, and then the load is dispersed throughout the base material 12. Further, if the contact body continues to rise,
As shown in FIG. 6, the base material 1 is easily and instantaneously removed from the mold 11.
The composite optical element 16 in which the resin layer 2 and the resin layer 13 are integrated is peeled off, and a desired composite optical element 16 is obtained.

According to the first embodiment of the present invention, the resin 15
The resin 15 reaches the optical effective diameter D or more and does not protrude from the outer peripheral portion of the substrate 12 even if there is a variation in the supply amount of It is possible to obtain the composite optical element 16 which does not cause a connected defect. Further, by securing a space for absorbing the variation in the resin supply amount, there is no increase in the volume of the composite optical element itself, and the product can be made compact.

[Second Embodiment of the Invention] A second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a view showing an optical element substrate of the composite optical element according to the second embodiment, and FIG.
FIG. 9 is a view showing one process of manufacturing a composite optical element, and FIG. 9 is a view showing a composite optical element.

In Embodiment 2 of the present invention, as shown in FIG. 7, a glass substrate 22 having one concave surface and the other convex surface is used as the optical element substrate, and the energy-curable resin is formed on the concave surface. By curing a resin layer made of an ultraviolet curable resin (hereinafter, referred to as a resin) 25 as above, a composite optical element 26 shown in FIG. 9 is formed.

The substrate 22 has a diameter R of 20 mm, an optical effective diameter D of 16.5 mm, and a radius of curvature of 7 up to a diameter of 17 mm.
A polished surface (hereinafter, referred to as a molding surface) 22a on which the resin layer 23 having a concave surface of 0 mm is placed is formed, and the center axis O of the base material 22 is located outside (outer edge) of the base material 22 outside a diameter of 17 mm.
A plane 22b perpendicular to the plane is formed. This flat surface 22b is formed by removing a shape portion obtained by extending the radius of curvature of the molding surface 22a to the outer peripheral portion of the base material 22 (similar to the dashed line portion 12d in FIG. 3) as in the first embodiment. I have. Therefore, as compared with the case where the molding surface 22a is formed up to the diameter R of the base material 22, the space for filling the resin 25 outside the optically effective diameter D is increased by the volume reduction of the base material 22, so that the resin supply amount This is advantageous for variations in The flat surface 22b is finished to a mirror surface with a roughness Ra = 0.050 μm by grinding with a # 1200 grindstone.
When observing with, the shape of the light source cannot be recognized as in the case of a pick-up surface, and the level of the light source can be clearly recognized. Therefore, light rays that pass through a part of the molding surface 22a on which the resin layer 23 of the base material 22 is mounted and a part of the flat surface 22b will not cause irregular reflection not only on the molding surface 22a within the optical effective diameter D but also on the flat surface 22b. Absent.

On the other hand, the opposite surface (lower surface in the figure) of the molding surface 22a of the substrate 22 is formed as a convex non-molding surface (surface on which the resin layer 23 is not placed) 22c. The formed polished surface has a radius of curvature of 30 mm.
The thickness of the base material 22 on the central axis O is 5 mm. The base material 22 has been previously subjected to a treatment for improving the adhesion between the base material 22 and the resin layer 23 by a known method using a silane coupling agent. Further, the supply amount of the resin 25 supplied on the molding surface 22a is such that the outermost peripheral portion of the resin layer 23 has an optical effective diameter D even when the supply amount varies.
It is set in advance so that it reaches the above and does not protrude from the outer peripheral portion of the base material 22.

Next, a method of manufacturing a composite optical element will be described with reference to FIGS. In the manufacture of the composite optical element, as shown in FIG. 8, an optical surface 21a for forming a desired resin layer 23 surface 23a is provided, the diameter is 19 mm, and the central axis is the central axis of the base material 22. A mold 21 is used, which is the same as O and is held up and down freely.

First, as shown in FIG. 7, a required amount of resin 25 is supplied onto the molding surface 22a of the substrate 22. Next, mold 2
1 is lowered to bring the optical surface 21a closer to the molding surface 22a,
The resin 25 on the molding surface 22a is pushed outward in the outer peripheral direction by the optical surface 21a. Then, as shown in FIG. 8, the resin 25 spread between the molding surface 22a of the base material 22 and the optical surface 21a of the mold 21 forms a resin layer 23 at a position where the resin layer 23 having a desired thickness is formed. Stop descending. At this time, the shape of the resin layer 23 is such that the thickness on the central axis O is 0.2 mm, the radius of curvature of the surface 23a is 50 mm, and the optical effective diameter D is 16.5 mm. Then, the outermost peripheral portion of the resin layer 23 reaches the outside of the molding surface 22a of the base material 22, and the flat surface 22b of the base material 22
It is above. That is, since the shape of the substrate 22 outside the optical effective diameter D is changed so as to widen the space formed by the substrate 22 and the mold 21, the resin 25 protrudes beyond the diameter R of the substrate 22. There is no.

Thereafter, a step of irradiating the entire surface of the resin layer 23 with energy to form a close contact body in which the mold 21 and the base material 22 and the cured resin layer 23 are integrated, and The step of peeling off the composite optical element 26 integrated with the resin layer 23 as shown in FIG. 9 is the same as in the first embodiment.

According to the manufacturing method of the second embodiment of the present invention, even if the supply amount of the resin 25 varies,
Does not reach the optically effective diameter D or more, and the resin 25 does not protrude from the outer peripheral portion of the base material 22, and does not cause a defect such as ghost or flare caused by irregular reflection of light rays, which leads to deterioration of optical performance. The optical element 26 can be obtained. Further, by securing a space for absorbing the variation in the resin supply amount, there is no increase in the volume of the composite optical element itself, and the product can be made compact.

In the second embodiment of the present invention, the plane 2
Although 2b is finished to a mirror surface by grinding with a # 1200 grindstone, the present embodiment is not limited to this, and a mirror surface can be obtained by grinding with a # 1000 to # 2000 grindstone.

In the first and second embodiments of the present invention, the shape of the outer edges of the substrates 12 and 22 is changed to the planes 12 b and 22.
Although the case where it is formed in b has been described, the shape is not limited to a flat surface and may be a concave surface, for example, as long as the space for filling the resins 15 and 25 outside the optical effective diameter D increases.

Further, in each of the first and second embodiments, a case has been described in which a glass substrate is used as the optical element substrate and an ultraviolet curable resin is used as the energy curable resin.
The present invention is not limited to this, and similar effects can be obtained by using a plastic substrate, a thermosetting resin, or another electron beam-curable resin.

As a method for forming the mirror surfaces of the flat surfaces 12a and 22a outside the optically effective diameter D of the base materials 12 and 22, polishing and grinding are used. The same effect can be obtained even if a mirror surface is created by using another method such as pressing.

Comparative Example In a comparative example, a composite optical element was manufactured using the substrate 32 shown in FIG. Substrate 32
Has a molding surface 32a having a shape similar to that of the second embodiment,
Outside the optically effective diameter D of the molding surface 32a on which the resin layer formed by spreading the resin 35 is placed, a plane 32b perpendicular to the central axis O of the base material 32 is sanded with sand of # 800 sand. , With a roughness Ra = 0.200 μm. Here, the appearance of the flat surface 32b is at a level at which the shape of the light source cannot be recognized when the base material 32 is placed between the light source and the observer for observation.

Next, a composite optical element is manufactured using the base material 32 by the same steps as in the second embodiment of the present invention, and the optical performance is compared with that of the composite optical element 26 manufactured in the second embodiment. did. As a result, there was more flare than in the case of the second embodiment, which was at a level where there was a problem in practical use.

The technical idea having the following configuration is derived from the specific embodiment. (1) In a composite optical element in which an energy-curable resin layer is mounted on the surface of an optical element substrate, the optical element substrate has an outer surface with respect to an optical effective diameter of a surface on which the resin layer is mounted. The base material has a shape in which a part of the base material is depressed so that the volume of the base material is reduced with respect to the shape in which the radius of curvature within the optical effective diameter of the surface is extended, and at least the resin on the surface exposed by the depression A composite optical element, wherein a portion on which the layer is mounted is a mirror surface.

(2) In a composite optical element in which an energy-curable resin layer is mounted on the surface of an optical element substrate, the optical element substrate is larger than the optical effective diameter of the surface on which the resin layer is mounted. The outside has a shape in which a part of the base material is removed so that the volume of the base material is reduced with respect to the shape in which the radius of curvature within the optical effective diameter of the surface is extended, and a part of the base material is removed. A composite optical element, characterized in that at least a portion on which the resin layer is placed on the surface exposed after the etching is a mirror surface having a roughness Ra of 0.020 to 0.050 μm.

(3) The composite optical element, wherein the mirror surface is a plane perpendicular to the central axis of the optical element base material.

(4) An energy-curable resin is supplied to the surface of the optical element substrate, and the resin is spread out by relatively bringing the substrate and the mold closer to each other so that the resin is spread between the mold and the substrate. After forming a desired resin layer, the resin layer is cured by irradiation of energy, and the cured resin layer and the mold are separated to produce a composite optical element having a desired resin layer. In the method, the outer side of the optical effective diameter of the surface on which the resin layer is mounted, the base material such that the volume of the base material is reduced with respect to a shape having an extended radius of curvature within the optical effective diameter of the surface. It has a shape with a part removed, and at least a part on which a resin layer is placed on a surface exposed after removing a part of the base material has a roughness Ra = 0.020 to 0.050 μm.
A method for producing a composite optical element, comprising using an optical element substrate having a mirror surface of m.

According to the above (2) to (4), the mirror surface has such a roughness that the shape of the light source can be clearly recognized, and light transmitted through the surface on which the resin layer is mounted and the mirror surface does not cause irregular reflection. Further, a composite optical element free from deterioration of optical performance such as ghost and flare due to irregular reflection of light rays can be obtained.

[0039]

As described above, according to the composite optical element of the first aspect of the present invention, when the resin layer is formed, the resin coming out of the effective optical diameter removes a part of the substrate. The optical element substrate is placed on the surface, so that the resin does not protrude from the optical element substrate, and the surface from which a part of the substrate has been removed is made a mirror surface, so that optical performance deterioration such as ghost and flare due to irregular reflection of light rays is eliminated It works.

According to the method for manufacturing a composite optical element of the second aspect of the present invention, the resin reaches the optical effective diameter or more without protruding from the optical element base material, and ghosts and flares due to irregular reflection of light rays. Thus, there is an effect that it is possible to obtain a composite optical element in which the optical performance is not deteriorated.

Further, since there is no increase in the volume of the composite optical element itself due to securing a space for absorbing variations in the resin supply amount, the product can be made compact.

[Brief description of the drawings]

FIG. 1 is a view showing an optical element substrate used for a composite optical element of the present invention.

FIG. 2 is a diagram showing an optical element substrate used in the first embodiment of the present invention.

FIG. 3 is a diagram showing an optical element substrate used in the first embodiment of the present invention.

FIG. 4 is a view showing a step of forming a resin layer according to the first embodiment of the present invention.

FIG. 5 is a view showing a step of separating the mold and the composite optical element according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a state in which the mold and the composite optical element according to Embodiment 1 of the present invention have been peeled off.

FIG. 7 is a diagram showing an optical element substrate used in Embodiment 2 of the present invention.

FIG. 8 is a view showing a step of forming a resin layer according to the second embodiment of the present invention.

FIG. 9 is a diagram showing a composite optical element according to a second embodiment of the present invention.

FIG. 10 is a diagram showing an optical element material used in a comparative example.

[Explanation of symbols]

 1,11 Mold 1a, 11a Optical surface 2,12,22 Optical element substrate 2a Surface on which resin layer is placed 2b, 12b, 22b Plane 12a, 22a Molding surface 13,23 Resin layer 15,25 Resin 16,26 Composite optical element

Claims (2)

[Claims] 1. A composite optical element in which an energy-curable resin layer is mounted on a surface of an optical element substrate, wherein the optical element substrate is outside an optical effective diameter of a surface on which the resin layer is mounted. Is a shape in which a part of the base material is removed so that the volume of the base material is reduced with respect to a shape in which the radius of curvature within the optical effective diameter of the surface is extended, and a part of the base material is removed. A composite optical element, wherein at least a portion of the surface exposed later on which the resin layer is placed is a mirror surface. 2. An energy-curable resin is supplied to the surface of the optical element base material, and the resin is spread out by relatively bringing the base material and the mold closer to each other, so that the resin is spread between the mold and the base material. After forming a desired resin layer, the resin layer is cured by irradiation of energy, and the cured resin layer and the mold are separated to produce a composite optical element having the desired resin layer. In one embodiment, the outer side of the optical effective diameter of the surface on which the resin layer is mounted is reduced such that the volume of the base material is reduced with respect to a shape in which the radius of curvature within the optical effective diameter of the surface is extended. A composite optical element, wherein the optical element substrate has a shape in which a portion is removed, and at least a portion on which a resin layer is placed on a surface exposed after removing a part of the base material is a mirror surface. Manufacturing method.