JP2011090056A - Composite optical element and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a composite optical element which hardly exerts a bad influence on image quality even when the shape accuracy of an optically effective plane of the composite optical element is deteriorated. <P>SOLUTION: The composite optical element 10 is produced by sticking two optical base materials 11, 12 to each other by using an ultraviolet-curable resin 4. The optical base material 11 or 12 has a cut part 11a or 12a which is formed in a part other than the optically effective plane and has the shape different from that of another part 111 or 121 on the same circumference. The cut parts 11a, 12a are arranged so that at least a part of one of the cut parts is not superposed on the other of the cut parts when viewed from the direction of the optical axis O. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite optical element in which, for example, two optical substrates are bonded together with a curable resin, and a method for manufacturing the same.

  With respect to the optical substrate constituting the optical element, for example, in assembling with a lens frame, a positioning mark or a notch is provided in order to specify the assembly direction of the optical element. Alternatively, the optical base material may have a non-axisymmetric base material shape with respect to the optical axis for reasons such as providing an abutting portion protruding in the optical axis direction in order to facilitate the attachment with the lens frame. is there.

This non-axisymmetric means that there is a shape that deviates from a shape that can be produced when a cross section is rotated around the optical axis.
As described above, a technique for forming a composite optical element (or a bonded optical element) by joining an optical substrate having a non-axisymmetric shape with a curable resin such as a UV curable resin or a thermosetting resin has been conventionally used. Are known.

  For example, in Patent Document 1, in a cemented lens in which two lenses (optical elements) are cemented with an adhesive (curable resin), a protrusion is formed outside a certain lens optical effective diameter, and another lens optical effective. There is disclosed a cemented lens provided with a support portion that supports a protruding portion outside the diameter.

JP-A-6-186405

However, as in Patent Document 1, an optical base material that has a non-axisymmetric shape by providing a protrusion and a support portion outside the lens optical effective diameter is overlapped with the non-axisymmetric portion in the optical axis direction. When joining is performed as described above, the following problems occur.
First, since the curable resin attracts the optical base material by curing shrinkage at the time of curing, stress acts on the optical base material and deformation of the optical base material occurs. At this time, when a normal axisymmetric optical base material is used, the rigidity of the optical base material is axisymmetrically uniform, so that the amount of deformation on a certain circumference is uniform at any position.

However, when a non-axisymmetric optical substrate is used, since the rigidity of the optical substrate is not axially symmetric, the deformation amount of the optical substrate becomes nonuniform on a certain circumference. This manifests itself as distortion on the optical substrate, so that the shape accuracy of the optical surface deteriorates.
Furthermore, when a composite optical element is created by joining two optical base materials having non-axisymmetric portions, if the resin is contracted in a state where the non-axisymmetric portions overlap in the optical axis direction, The distortion on the optical base material caused by the presence of the optical base material overlaps when viewed from the optical axis direction.

In this case, when the light beam passes through a plurality of distorted portions on the optical substrate, the aberration is greatly deteriorated locally. Therefore, there is a problem that the influence on the entire optical performance is large.
The present invention has been made to solve such a problem, and an object of the present invention is to provide a composite optical element in which deterioration of the shape accuracy of the optically effective surface hardly affects the image quality, and a manufacturing method thereof.

In order to achieve the above object, the composite optical element according to the present invention comprises:
A composite optical element in which at least two optical substrates are bonded with a curable resin,
The at least two optical base materials each include a non-axisymmetric portion formed on a portion other than the optically effective surface and having a shape different from other portions on the same circumference,
When each non-axisymmetric part is viewed from the optical axis direction, at least a part of one non-axisymmetric part is arranged so as not to overlap the other non-axisymmetric part.

In addition, when each of the non-axisymmetric portions is viewed from the optical axis direction, it is preferable that the overlapping range is not more than half of the smaller region of the non-axisymmetric portion.
Further, each of the non-axisymmetric portions is preferably arranged at a position where the angles in the rotation direction about the optical axis are substantially equal.

The present invention also provides a first optical substrate and a second optical substrate, each having a non-axisymmetric portion formed on a portion other than the optically effective surface and having a shape different from other portions on the same circumference. A method for manufacturing a composite optical manufacturing element in which an optical substrate is bonded with a curable resin,
Discharging the curable resin to the first optical substrate;
When the non-axisymmetric part of the first optical base and the non-axisymmetric part of the second optical base are viewed from the optical axis direction, at least a part of one non-axisymmetric part is A step of positioning the optical bases so as not to overlap with the non-axisymmetric part;
Stretching the curable resin with the second optical substrate;
And a step of curing the curable resin.

Further, in the step of positioning the optical substrates, when the respective non-axisymmetric portions are viewed from the optical axis direction, the overlapping range is less than half of the region of either of the non-axisymmetric portions. It is preferably positioned.
Moreover, in the step of positioning the optical substrates,
Each of the non-axisymmetric portions is preferably positioned so that the angles in the rotational direction about the optical axis are substantially equal.

  According to the present invention, it is possible to provide a composite optical element in which deterioration of the shape accuracy of the optically effective surface hardly affects the image quality and a manufacturing method thereof.

3 is a cross-sectional view of two optical substrates to be bonded in Embodiment 1. FIG. It is a top view of an optical base material. It is a top view of an optical base material. It is a top view when an optical base material and an optical base material are made to contact on a bonding surface. It is sectional drawing same as the above. It is sectional drawing of the joining optical element formed by bonding together two optical base materials. 3 is a diagram showing a schematic flowchart of the first embodiment. FIG. 6 is a cross-sectional view of two optical substrates to be bonded together in Embodiment 2. FIG. It is a top view of an optical base material. It is a top view of an optical base material. It is a top view of the joining optical element formed by bonding together two optical base materials. It is sectional drawing same as the above. FIG. 10 is a diagram showing a schematic flowchart of a second embodiment. 6 is a cross-sectional view of two optical substrates to be bonded in Embodiment 3. FIG. It is a top view of an optical base material. It is a top view of an optical base material. It is a top view of the joining optical element formed by bonding together two optical base materials. It is sectional drawing same as the above. FIG. 10 is a diagram showing a schematic flowchart of a third embodiment. 6 is a cross-sectional view of two optical substrates to be bonded in Embodiment 4. FIG. It is a top view of an optical base material. It is a top view of an optical base material. It is a top view of the joining optical element formed by bonding together two optical base materials. It is sectional drawing same as the above. FIG. 10 is a diagram showing a schematic flowchart of a fourth embodiment. FIG. 9 is a cross-sectional view of two optical substrates to be bonded together in a fifth embodiment. It is sectional drawing of the joining optical element formed by bonding together two optical base materials. FIG. 10 is a diagram showing a schematic flowchart of a fifth embodiment. It is sectional drawing of the three optical base materials bonded together in Embodiment 6. FIG. It is a top view of an optical base material. It is a top view of an optical base material. It is a top view of an optical base material. It is sectional drawing of the state which bonded together two optical base materials. It is sectional drawing of the state arrange | positioned so that the optical axis of an intermediate | middle composite optical element and an optical base material may correspond. It is a top view of the joining optical element formed by bonding an intermediate | middle composite optical element and an optical base material. It is sectional drawing same as the above. FIG. 10 is a diagram showing a schematic flowchart of a sixth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]

FIG. 1 is a cross-sectional view of two optical substrates 11 and 12 to be bonded together in the first embodiment. FIG. 2 is a plan view of the optical substrate 11, and FIG. 3 is a plan view of the optical substrate 12.
In FIG. 1, an optical substrate 11 as a first optical substrate has a biconcave lens shape. This optical substrate 11 has a bonding surface 11A and an anti-bonding surface 11B each having an optically effective surface. Here, the optically effective surface is a surface that can be used as an optical surface, and is defined as a surface within the optically effective diameter D0 in this embodiment.
The bonding surface 11A has a spherical shape with a curvature radius R1a of R1a = 8 mm. The bonding surface 11A is not limited to a spherical shape, and may be an aspherical shape, for example. The same applies to other embodiments.

  The anti-bonding surface 11B has an aspherical shape with an approximate curvature radius R1b of R1b = 38 mm. The anti-bonding surface 11B is not limited to an aspheric shape, and may be a spherical shape, for example. The same applies to other embodiments.

Here, the “bonding surface” refers to the surface of the optical substrate that comes into contact with the curable resin (ultraviolet curable resin 4 in the present embodiment), which will be described later. Is the surface of the optical substrate that faces the bonded surface across the optical substrate. The same applies to other embodiments.
This optical substrate 11 is a glass molded lens having a center thickness t1 of t1 = 0.8 mm and an outer diameter D1 of D1 = φ10 mm. S-BSL7 (manufactured by OHARA INC.) Was used as the optical glass material.

As shown in FIG. 2, the optical base 11 has a cut portion 11a (non-axisymmetric portion) in which a part of the outer periphery (contour) of the circular lens in plan view is cut off by a straight line 111a in the XY plane. Have. This is a so-called D-cut lens (a lens cut into a D shape in plan view).
Here, the non-axisymmetric part is an area formed in a part other than the optically effective surface in FIG. 2 and having a shape different from that of the other part 111 on the same circumference centered on the optical axis O (this embodiment). In the example, it refers to the cut portion 11a). The same applies to other embodiments.

  In the present embodiment, the D-shaped cut portion 11a is described as an example of the non-axisymmetric portion, but the present invention is not limited to this. For example, it may be any of a positioning mark, an abutting portion with a lens frame, which will be described later, a cut trace of a resin inlet, a resin inlet, and the like. Further, for example, an H cut lens in which the opposite side surfaces are cut off at the outer periphery of the circular lens in plan view may be used. The same applies to other embodiments.

The optical base 11 has a flat surface 11b perpendicular to the optical axis O formed on the outer periphery of the bonding surface 11A (see FIG. 1 and the like).
The flat surface 11b is a ring-shaped plane excluding the cut portion 11a. However, the flat surface 11b is not necessarily a surface perpendicular to the optical axis O, and may be a curved surface instead of a flat surface. These points are the same in other embodiments.

Next, the optical substrate 12 as the second optical substrate has a biconvex lens shape. Similar to the optical substrate 11, the optical substrate 12 has a bonding surface 12A and an anti-bonding surface 12B each having an optically effective surface. The bonding surface 12A has a spherical shape with a curvature radius R2a of R2a = 8 mm.
The anti-bonding surface 12B has an aspherical shape with an approximate curvature radius R2b of R2b = 30 mm. Note that the bonding surface 12 </ b> A and the anti-bonding surface 12 </ b> B are not limited in surface shape as in the optical substrate 11. The same applies to other embodiments.

This optical substrate 12 is a plastic molded lens having a center thickness t2 of t2 = 5 mm and an outer diameter D2 of D2 = φ10 mm. In this embodiment, a thermoplastic resin of PC (polycarbonate) resin (Iupizeta EP5000: manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used as the plastic.
As shown in FIG. 3, the optical base 12 has a cut portion 12a (non-axisymmetric portion) in which a part of the outer periphery (contour) of the circular lens in plan view is cut off by a straight line 121a in the X′-Y ′ plane. ). The cut portion 12a has a different shape from other portions 121 on the same circumference centered on the optical axis O. Moreover, the optical base material 12 is what is called a D cut lens similarly to the above-mentioned.

In this embodiment, the case where two optical base materials 11 and 12 are bonded together will be described, but the present invention is not limited to this. For example, three or more optical substrates may be bonded together.
In the present embodiment, the non-axisymmetric part is described as the D-cut part, but the present invention is not limited to this. For example, it may be any of a positioning mark, an abutting portion with a lens frame, which will be described later, a cutting trace of a resin inlet, a resin inlet, or the like. The same applies to other embodiments.

FIG. 4 is a plan view when the optical substrate 11 and the optical substrate 12 are brought into contact with each other on the bonding surface. FIG. 5 is a cross-sectional view thereof, and FIG. 6 is a cross-sectional view of a bonded optical element formed by bonding two optical base materials 11 and 12 together.
In FIG. 4, the cut part 11a of the optical base material 11 and the cut part 12a of the optical base material 12 are optical so that at least a part of one cut part does not overlap (do not match) the other cut part. A base material 11 and an optical base material 12 are arranged.
In the present embodiment, the arrangement in which the center of the cut part 11a and the center of the cut part 12a coincide with each other is set to 0 °, and the optical axis O between the cut parts 11a and 12a is rotated. The angle θ in the rotation direction was 30 °. Further, the angle θ in the rotation direction around the optical axis O is preferably 45 ° or more. Thereby, when each cut part is seen from an optical axis direction, the range which mutually overlaps is less than half of the area | region of either cut part.

In FIG. 5, gap portions 14 a and 14 b are formed at the edges of the contact portions when the optical base materials 11 and 12 are brought into contact with each other on the bonding surfaces. Therefore, as shown in FIG. 6, an ultraviolet curable resin 4 is applied to the gaps 14 a and 14 b and cured to obtain the bonded optical element 10.
(Lamination method)

Next, a bonding method will be described.
FIG. 7 is a diagram showing a schematic flowchart of the present embodiment.
As shown in FIG. 1, the bonding apparatus (the whole is not shown) has a pair of opposing base material holding portions 71 and 72. The base material holding portions 71 and 72 have a cylindrical shape, and can hold the optical base materials 11 and 12 individually by vacuum suction with the inner space being evacuated.

Thus, the one base material holding part 71 vacuum-sucks the optical base material 11. Further, the other base material holding portion 72 vacuum-sucks the optical base material 12.
At the time of bonding, the optical base material 11 is placed down, the optical base material 12 is placed up, and the bonding surfaces 11A and 12A are arranged with a predetermined distance therebetween in the optical axis O direction (FIGS. 1 and 7). S11). It should be noted that the optical substrates 11 and 12 are arranged to face each other in the same manner in other embodiments. In the following embodiments, illustration of substrate holding parts 71 and 72 is omitted.

Next, in a state where the optical base materials 11 and 12 are vacuum-sucked, positioning is performed such that the angle θ in the rotation direction about the optical axis O is 30 ° (S12 in FIGS. 4 and 7).
In addition, the process of S11 may be performed after the process of S12, for example, not only when performing the process of S12 (positioning process) after the process of S11 (opposite process). This point is the same in other embodiments.

Next, as shown in FIG. 5, the optical base 11 and the optical base 12 are moved relatively close to each other in the direction of the optical axis O to bring the bonding surface 11A and the bonding surface 12A into contact (S13 in FIG. 7). ).
Next, as shown in FIG. 6, the ultraviolet curable resin 4 is applied to the gaps 14a and 14b formed at the edges of the contact portions of the optical substrates 11 and 12 (S14 in FIG. 7).
The bonding surfaces 11A and 12A are subjected to a hydrophilic treatment by ultraviolet ozone treatment in advance and then treated with a silane coupling agent to improve the adhesion between the optical base materials 11 and 12 and the ultraviolet curable resin 4. I have to. Here, the hydrophilic treatment may use plasma discharge instead of the ultraviolet ozone treatment. Further, the process for increasing the adhesion is performed in the same manner in the other embodiments.

Next, with this state maintained, the ultraviolet curable resin 4 is irradiated with ultraviolet rays using the ultraviolet lamp 5 to cure the ultraviolet curable resin 4 (S15 in FIGS. 6 and 7). In this embodiment, ultraviolet rays having a substantially uniform illuminance distribution with an illuminance of 20 ± ² mW / cm ² are irradiated for 60 seconds. Thereby, the bonded optical element 10 was obtained.

In the vicinity of the cut portions 11a and 12a (non-axisymmetric portions) of the optical base materials 11 and 12, non-axisymmetric deformation occurs due to stress at the time of curing of the ultraviolet curable resin 4, so that the surface shape of the optically effective surface May get worse. According to the present embodiment, the cut portions 11a and 12a are joined by being shifted by 30 ° in the rotation direction around the optical axis O from the arrangement in which the centers of the cut portions 11a and 12a coincide.
For this reason, the location where the shape accuracy of the optically effective surface deteriorates does not completely match, and at least a part of one cut portion does not overlap the other cut portion. In this way, it is possible to obtain the composite optical element 10 in which deterioration of the shape accuracy of the optically effective surface hardly affects the optical performance (image quality).

Further, in the present embodiment, when viewed from the optical axis O direction, the range 13a (hatched portion) where the cut portion 11a and the cut portion 12a overlap each other is less than half of the area of each cut portion 11a, 12a. Thus, it is preferable that they are shifted. This point is the same in other embodiments. In this way, by separating the non-axisymmetric portions from each other, it is possible to suppress duplication of non-axisymmetric deformation due to stress at the time of curing and to further reduce the influence on optical performance deterioration.
[Embodiment 2]

FIG. 8 is a cross-sectional view of the two optical substrates 21 and 22 to be bonded together in the second embodiment. FIG. 9 is a plan view of the optical base material 21, and FIG. 10 is a plan view of the optical base material 22.
In FIG. 8, an optical substrate 21 as a first optical substrate has a biconcave lens shape. This optical base material 21 has a bonding surface 21A and an anti-bonding surface 21B each having an optically effective surface.

  The bonding surface 21A has an aspherical shape with an approximate curvature radius R1a of R1a = 8 mm. The anti-bonding surface 21B has an aspherical shape with an approximate curvature radius R1b of R1b = 38 mm. This optical substrate 21 is a glass molded lens having a center thickness t1 of t1 = 0.8 mm and an outer diameter D1 of D1 = φ10 mm. S-BSL7 (manufactured by OHARA INC.) Was used as the optical glass material.

As shown in FIG. 9, the optical base 21 has a cut portion 21a (non-axisymmetric portion) in which a part of a circular lens in plan view is cut off by a straight line 211a.
The optical base material 21 has a flat surface 21b in a direction perpendicular to the optical axis O formed on the outer periphery of the bonding surface 21A (see FIG. 8 and the like). The flat surface 21b is a ring-shaped plane excluding the cut portion 21a.

Next, the optical substrate 22 as the second optical substrate has a biconvex lens shape. The optical base material 22 has a bonding surface 22A and an anti-bonding surface 22B each having an optically effective surface. The bonding surface 22A has an aspherical shape with an approximate curvature radius R2a of R2a = 13 mm. The anti-bonding surface 22B has an aspherical shape with an approximate radius of curvature R2b of R2b = 80 mm.
This optical substrate 22 is a plastic molded lens having a center thickness t2 of t2 = 5 mm and an outer diameter D2 of D2 = φ10 mm.

In this embodiment, a thermoplastic resin of PC (polycarbonate) resin (Iupizeta EP5000: manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used as the plastic.
As shown in FIG. 10, the optical base material 22 has a cut portion 22a (non-axisymmetric portion) in which a part of a circular lens in plan view is cut off by a straight line 221a. The cut portion 22a has a shape different from that of the other portion 221 on the same circumference around the optical axis O.

11 is a plan view of a bonded optical element 20 formed by bonding two optical base materials 21 and 22, and FIG. 12 is a cross-sectional view thereof.
In FIG. 11, the cut part 21a of the optical base material 21 and the cut part 22a of the optical base material 22 have an arrangement in which the center of the cut part 21a and the center of the cut part 22a coincide with each other, and the cut parts 21a, 22a. The optical base material 21 and the optical base material 22 are positioned so that the angle θ in the rotation direction about the optical axis O between them is 180 °. Note that the angle θ is not limited to 180 °, and is arranged so that at least a part of one cut portion does not overlap (not coincide with) the other cut portion when viewed from the direction of the optical axis ○. It should be.

Moreover, it is preferable that the range which mutually overlaps when it sees from the optical axis O direction is half or less of the area | region of the cut part 21a and the cut part 22a.
In the present embodiment, the cut portions are arranged at positions where the angles in the rotation direction about the optical axis are substantially equal. Therefore, the overlapping range of the cut part 21a and the cut part 22a when viewed from the optical axis O direction is zero.

Also, as shown in FIG. 12, when the optical base materials 21 and 22 are bonded together, the ultraviolet curable resin 4 sandwiched between the optical base materials 21 and 22 is cured to obtain the bonded optical element 20. Yes. Here, the resin thickness of the bonded optical element 20 formed by bonding the two optical substrates 21 and 22 is the resin thickness at the center resin thickness t0 = 0.8 mm and the optical effective diameter D0 (φ8.8 mm) of the resin layer. t3 = 0.2 mm.
(Lamination method)

Next, a bonding method will be described.
FIG. 13 is a diagram showing a schematic flowchart of the present embodiment.
At the time of bonding, the optical base material 21 is placed down, the optical base material 22 is placed up, and the bonding surfaces 21A and 22A are positioned facing each other with a predetermined distance in the optical axis O direction (S21 in FIGS. 8 and 13). ).

  Next, in a state where the optical base materials 21 and 22 are vacuum-adsorbed, the optical base material 21 and the optical base material 22 are arranged so that the cut portion 21a and the cut portion 22a do not coincide with each other, and positioning of the base materials is performed. Do. In the present embodiment, the arrangement in which the center of the cut portion 21a and the center of the cut portion 22a coincide with each other is set to 0 °, and the rotation angle θ about the optical axis O is positioned to be 180 °. (S22 in FIGS. 11 and 13).

  Next, a desired amount of curable resin (ultraviolet curable resin 4 in the present embodiment) is discharged onto the bonding surface 21A (S23 in FIGS. 8 and 13). The discharge amount of the ultraviolet curable resin 4 was set to such an amount that the resin diameter becomes equal to or larger than the optical effective diameter D0 when the center resin thickness t0 becomes a desired thickness (see FIG. 12).

In the present embodiment, the ultraviolet curable resin 4 is discharged after positioning the optical substrate 21 and the optical substrate 22 in the rotation direction around the optical axis O. However, this order may be reversed and the optical base 21 and the optical base 22 may be positioned in the rotational direction after the ultraviolet curable resin 4 is discharged. This point is the same in other embodiments.
In this state, the optical base material 21 and the optical base material 22 are moved relatively close to each other in the optical axis O direction. Then, the ultraviolet curable resin 4 is stretched by the bonding surface 22A until the center resin thickness t0 becomes a desired thickness (S24 in FIG. 13).

While maintaining this state, the ultraviolet lamp 5 is irradiated with ultraviolet rays through the optical base 21 to cure the ultraviolet curable resin 4 (S25 in FIGS. 12 and 13). In this embodiment, ultraviolet rays having a substantially uniform illuminance distribution with an illuminance of 20 ± ² mW / cm ² are irradiated for 60 seconds. Thereby, the bonded optical element 20 was obtained.

In the vicinity of the cut portions 21a and 22a (non-axisymmetric portions) of the optical base materials 21 and 22, there is a possibility that the surface shape of the optically effective surface is deteriorated due to non-axisymmetric deformation accompanying the curing shrinkage of the resin layer. According to the present embodiment, the cut portions 21a and 22a are joined so as to be shifted by 180 ° in the rotation direction about the optical axis O from the arrangement in which the centers of the cut portions 21a and 22a coincide.
In this way, the cut portions are arranged at positions where the angles in the rotation direction about the optical axis are substantially equal, whereby the non-axisymmetric deformation due to the stress at the time of curing is most distant. Accordingly, it is possible to suppress duplication of deformation and reduce the influence on optical performance degradation.

[Embodiment 3]

FIG. 14 is a cross-sectional view of two optical base materials 31 and 32 to be bonded together in the third embodiment. FIG. 15 is a plan view of the optical substrate 31, and FIG. 16 is a plan view of the optical substrate 32.
In FIG. 15, an optical substrate 31 as a first optical substrate has a biconcave lens shape. The optical substrate 31 has a bonding surface 31A and an anti-bonding surface 31B each having an optically effective surface.

The bonding surface 31A has an aspherical shape with an approximate curvature radius R1a of R1a = 8 mm. Further, the anti-bonding surface 31B has an aspherical shape with an approximate curvature radius R1b of R1b = 38 mm.
This optical substrate 31 is a plastic molded lens having a center thickness t1 of t1 = 0.8 mm and an outer diameter D1 of D1 = φ10 mm.

In this embodiment, a thermoplastic resin of PC (polycarbonate) resin (Iupizeta EP5000: manufactured by Mitsubishi Gas Chemical Company, Inc.) is used as the optical base material 31.
As shown in FIG. 15, the optical substrate 31 has a cut portion 31a (non-axisymmetric portion) in which a part of a planar view circular lens is cut off by a straight line 311a. The cut portion 31a has a shape different from that of the other portion 311 on the same circumference around the optical axis O.

  The optical base material 31 is formed with a flat surface 31b in a direction perpendicular to the optical axis O on the outer periphery of the bonding surface 31A (see FIG. 14 and the like). The flat surface 31b is a ring-shaped plane excluding the cut portion 21a.

Next, the optical substrate 32 as the second optical substrate has a convex meniscus lens shape. The optical base material 32 has a bonding surface 32A and an anti-bonding surface 32B each having an optically effective surface. The bonding surface 32A has an aspherical shape with an approximate curvature radius R2a of R2a = 6.4 mm. Further, the anti-bonding surface 32B has an aspherical shape with an approximate curvature radius R2b of R2b = 16 mm.
The optical substrate 32 is a plastic molded lens having a center thickness t2 of t2 = 2.4 mm and an outer diameter D2 of D2 = φ10 mm.

In the present embodiment, a thermoplastic resin of COP (cycloolefin polymer) resin (Zeonex 480R: manufactured by Nippon Zeon Co., Ltd.) is used as the optical substrate 32.
As shown in FIG. 16, the optical base material 32 has a cut portion 32a (non-axisymmetric portion) in which a part of a circular lens in plan view is cut off by a straight line 321a.

FIG. 17 is a plan view of a bonded optical element 30 formed by bonding two optical base materials 31 and 32 together. FIG. 18 is a cross-sectional view thereof.
In FIG. 17, the cemented optical element 30 has an angle θ in the rotation direction about the optical axis O between the cut portions 21a and 22a, with the arrangement where the center of the cut portion 21a coincides with the center of the cut portion 22a being 0 °. The optical base material 31 and the optical base material 32 are arranged so that the angle becomes 180 °. Note that the angle θ in the rotation direction around the optical axis O is not limited to 180 °. When viewed from the direction of the optical axis O, it is only necessary that at least a part of one of the cut portions is disposed so as not to overlap (do not match) the other cut portion. Moreover, it is preferable that the range which mutually overlaps seeing from the optical axis O direction is below half of the area | region of the cut part 31a and the cut part 32a.

  In the present embodiment, the cut portions are arranged at positions where the angles in the rotation direction about the optical axis are substantially equal. Therefore, the overlapping range when viewed from the optical axis O direction of the cut portion 31a of the optical base material 31 and the cut portion 32a of the optical base material 32 is zero.

Further, as shown in FIG. 18, when the optical base materials 31 and 32 are bonded together, the ultraviolet curable resin 4 sandwiched between the optical base materials 31 and 32 is cured to obtain the bonded optical element 30. Yes. Here, the resin thickness of the bonded optical element 30 formed by bonding the two optical substrates 31 and 32 is the center resin thickness t0 = 0.2 mm, and the resin thickness t3 = the optical effective diameter D0 (φ15 mm) of the resin layer. 1.0 mm.
(Lamination method)

Next, a bonding method will be described.
FIG. 19 is a diagram showing a schematic flowchart of the present embodiment.
At the time of bonding, the optical base material 31 is placed down, the optical base material 32 is placed up, and the bonding surfaces 31A and 32A are positioned facing each other at a predetermined distance in the optical axis O direction (S31 in FIGS. 14 and 19). ).

  Next, in a state where the optical base materials 31 and 32 are vacuum-sucked, the optical base material 31 and the optical base material 32 are arranged so that the center of the cut portion 31a and the center of the cut portion 32a do not coincide with each other. Position the axis. In the present embodiment, the arrangement in which the center of the cut portion 31a and the center of the cut portion 32a coincide with each other is 0 °, and the angle θ in the rotation direction about the optical axis O between the cut portions 31a and 32a is shifted by 180 °. In this way, positioning is performed (S32 in FIGS. 17 and 19).

Next, a desired amount of curable resin (ultraviolet curable resin in the present embodiment) is discharged onto the bonding surface 31A (S33 in FIGS. 14 and 19). The discharge amount of the ultraviolet curable resin 4 was set to such an amount that the resin diameter becomes equal to or larger than the optical effective diameter D0 when the center resin thickness t0 reaches a desired thickness (see FIG. 18).
In this state, the optical base material 31 and the optical base material 32 are moved relatively close to each other in the optical axis O direction. Then, the ultraviolet curable resin 4 is stretched by the bonding surface 32A until the center resin thickness t0 becomes a desired thickness (S34 in FIG. 19).

While maintaining this state, ultraviolet rays are irradiated by the ultraviolet lamp 5 through the optical base 31 to cure the ultraviolet curable resin 4 (S35 in FIGS. 18 and 19). In this embodiment, ultraviolet rays having an almost uniform illuminance distribution with an illuminance of 15 ± ² mW / cm ² are irradiated for 80 seconds. Thereby, the bonded optical element 30 was obtained.

According to the present embodiment, the cut portions 31a and 32a are joined so as to be shifted by 180 ° in the rotation direction about the optical axis O from the arrangement in which the centers of the cut portions 31a and 32a coincide. Therefore, it is possible to suppress duplication of non-axisymmetric deformation due to stress at the time of curing, and to further reduce the influence on optical performance deterioration.
Further, the resin layer of the ultraviolet curable resin 4 has a concave meniscus shape, and the resin layer is thick even on the outer periphery of the optically effective surface.
When the thickness of the resin layer is large, the amount of base material deformation due to curing shrinkage of the ultraviolet curable resin 4 is large. Therefore, in the periphery of the cut portions 31a and 32a, it is expected that the deterioration of the shape accuracy of the optically effective surface is greater than that of the thin resin layer. However, in the present embodiment, the cut portions 31a and 32a do not overlap with each other in the direction of the optical axis O, so that the influence on optical performance deterioration is small.

The optical base materials 31 and 32 are both plastic molded lenses. This plastic molded lens has characteristics that a glass lens does not have, such as high impact resistance and easy shape. On the other hand, since the rigidity is generally lower than that of a glass lens, an optically effective surface caused by non-axisymmetric deformation accompanying the curing shrinkage of the resin layer around the cut portions 31a and 32a (non-axisymmetric portions). The deterioration of the shape accuracy tends to increase.
On the other hand, in the present embodiment, the cut portions 31a and 32a are bonded so as not to overlap each other in the direction of the optical axis O. Therefore, even a plastic molded lens can reduce the influence on optical performance deterioration. it can.

[Embodiment 4]

20 is a cross-sectional view of the two optical substrates 41 and 42 to be bonded together in the fourth embodiment, FIG. 21 is a plan view of the optical substrate 41, and FIG. It is a top view.
In FIG. 20, an optical substrate 41 as a first optical substrate has a biconcave lens shape. The optical substrate 41 has a bonding surface 41A and an anti-bonding surface 41B each having an optically effective surface.

The bonding surface 41A has an aspherical shape with an approximate curvature radius R1a of R1a = 8 mm. Further, the anti-bonding surface 41B has an aspherical shape with an approximate curvature radius R1b of R1b = 38 mm.
This optical substrate 41 is a plastic molded lens having a center thickness t1 of t1 = 0.8 mm and an outer diameter D1 of D1 = φ12.4 mm.

In the present embodiment, a thermoplastic resin of COP (cycloolefin polymer) resin (ZEONEX 480R: manufactured by Nippon Zeon Co., Ltd.) is used as the plastic.
As shown in FIGS. 20 and 21, the optical base 41 has an abutting portion 41 a (non-axial) with a lens frame that protrudes in the direction of the optical axis O on the outer periphery of the anti-bonding surface 41 B of the circular lens in plan view. (Symmetry part). The three abutting portions 41a are provided so that the angles in the rotation direction about the optical axis O are substantially equal (120 ° in the present embodiment).

In the present embodiment, the abutting portion 41a protrudes in the direction of the optical axis O. The rigidity of the optical base material 41 is enhanced by the abutting portion 41a.
The optical base material 41 has a flat surface 41b perpendicular to the optical axis O formed on the outer periphery of the bonding surface 41A (see FIG. 20 and the like). The flat surface 41b is a ring-shaped plane excluding the abutting portion 41a described later.

Next, the optical substrate 42 as the second optical substrate has a convex meniscus lens shape. The optical base material 42 has a bonding surface 42A and an anti-bonding surface 42B each having an optically effective surface. The bonding surface 42A has an aspherical shape with an approximate curvature radius R2a of R2a = 6.4 mm. The anti-bonding surface 42B has an aspherical shape with an approximate curvature radius R2b of R2b = 16 mm.
The optical base 42 is a plastic molded lens having a center thickness t2 of t2 = 2.4 mm and an outer diameter D2 of D2 = φ12.4 mm.

In the present embodiment, a thermoplastic resin of PC (polycarbonate) resin (Iupizeta EP5000: manufactured by Mitsubishi Gas Chemical Co., Ltd.) is used as the optical substrate 42.
As shown in FIGS. 20 and 22, the optical base material 42 has three abutting portions 42 a (non-axisymmetric portions) with a lens frame that protrude in the direction of the optical axis O on the outer periphery of the optical effective diameter D 0. Have. The three abutting portions 42a are provided so that the angles in the rotation direction around the optical axis O are substantially equal (120 ° in the present embodiment). This 42a has a different shape from other portions 111 on the same circumference centered on the optical axis O.
In the present embodiment, the abutting portion 42a protrudes in the direction of the optical axis O. The rigidity of the optical base material 42 is enhanced by the abutting portion 42a.

FIG. 23 is a plan view of a bonded optical element 40 formed by bonding two optical base materials 41 and 42 together. FIG. 24 is a cross-sectional view thereof.
In FIG. 23, when the three abutting portions 41a of the optical base material 41 and the three abutting portions 42a of the optical base material 42 are viewed from the optical axis ◯ direction, at least a part of one of the cut portions. However, the optical base material 41 and the optical base material 42 are arranged so as not to overlap (not coincide with) the other cut portion.
In the present embodiment, the abutting portions 41a and 42a of the optical base material 41 and the optical base material 42 match the center of one of the abutting portions 41a with the center of one of the abutting portions 42a. The rotation position was set to 0 °, and the optical axis O was rotated as the center, and the rotation direction angle θ about the optical axis O was set to 60 °.

The angle θ is not limited to 60 °. The abutting portions 41a and 42b do not have to coincide with the optical axis O direction. At this time, it is preferable that the overlapping range when viewed from the direction of the optical axis O is not more than half of the area of the abutting portion 41a and the abutting portion 42a.
In the present embodiment, the abutting portions are arranged at positions where the angles in the rotation direction about the optical axis are substantially equal. Therefore, the overlapping range when viewed from the optical axis O direction of the abutting portion 41a of the optical base material 41 and the abutting portion 42a of the optical base material 42 is zero.

Further, as shown in FIG. 24, when the optical base materials 41 and 42 are bonded together, the thermosetting resin 6 sandwiched between the optical base materials 41 and 42 is cured to obtain the bonded optical element 40. Yes. Here, the resin thickness of the bonded optical element 40 formed by bonding the two optical substrates 41 and 42 is the resin thickness at the center resin thickness t0 = 0.2 mm and the optical effective diameter D0 (φ8.8 mm) of the resin layer. t3 = 0.8 mm.
(Lamination method)

Next, a bonding method will be described.
FIG. 25 is a diagram showing a schematic flowchart of the present embodiment.
At the time of bonding, the optical base material 41 is faced down, the optical base material 42 is faced up, and the bonding surfaces 41A and 42A are positioned facing each other at a predetermined distance in the optical axis O direction (S41 in FIGS. 20 and 25). ).

Next, in a state where the optical base materials 41 and 42 are vacuum-adsorbed, the three abutting portions 41a of the optical base material 41 and the three abutting portions 42a of the optical base material 42 do not match. An optical substrate 41 and an optical substrate 42 are disposed.
In the present embodiment, in the abutting portions 41a and 42a of the optical base material 41 and the optical base material 42, the center of one location of the abutting portion 41a is coincident with the center of one location of the abutting portion 42a. The rotation position is set to 0 °, and the optical axis O is rotated as the center, and the rotation direction angle θ about the optical axis O between the abutting portions 41a and 42a is set to 60 ° (FIG. 23, FIG. 23). S42 in FIG. 25).

Next, a desired amount of a curable resin (the thermosetting resin 6 in the present embodiment) is discharged onto the bonding surface 41A of the optical substrate 41 (S43 in FIGS. 20 and 25). Here, the discharge amount of the thermosetting resin 6 was set to such an amount that the resin diameter becomes equal to or larger than the optical effective diameter D0 when the center resin thickness t0 becomes the desired thickness (see FIG. 24).
Thereafter, the optical base 41 and the optical base 42 are moved relatively close to each other in the direction of the optical axis O until the resin thickness reaches the desired thickness by the bonding surface 42A of the optical base 42, and the thermosetting resin 6 is pressed. (S44 in FIG. 25). While maintaining this state, the resin layer is cured by placing in a heating furnace and heating at a predetermined temperature for a predetermined time (S45 in FIGS. 24 and 25). Thereby, the bonded optical element 40 was obtained.

Since the rigidity is increased in the vicinity of the abutting portions 41a and 42a (non-axisymmetric portions) of the optical base materials 41 and 42 with the lens frame, the amount of deformation due to curing shrinkage of the resin layer is reduced. Accordingly, when the resin layer is cured and contracted, the optical base material is deformed non-axisymmetrically with respect to the optical axis O. Therefore, in the vicinity of the contact portions 41a and 42a with the lens frame, the optical effective surface The surface shape may be deteriorated.
In the present embodiment, the rotation direction about the optical axis O is shifted from the arrangement in which the centers of the abutting portions 41a and 42a with the lens frame whose shape accuracy deteriorates coincide with each other. Thereby, since the abutting portions 41a and 42a with the lens frame are bonded so as not to overlap each other, the influence on the optical performance deterioration can be reduced.

[Embodiment 5]

FIG. 26 is a cross-sectional view of the two optical substrates 51 and 52 to be bonded together in the fifth embodiment.
In FIG. 26, an optical substrate 51 as a first optical substrate has a biconcave lens shape. The optical substrate 51 has a bonding surface 51A and an anti-bonding surface 51B each having an optically effective surface.
The bonding surface 51A has an aspherical shape with an approximate curvature radius R1a of R1a = 8 mm. Further, the anti-bonding surface 51B has an aspherical shape with an approximate curvature radius R1b of R1b = 38 mm.

The optical substrate 51 is a plastic molded lens having a center thickness t1 of t1 = 0.8 mm and an outer diameter D1 of D1 = φ10 mm.
In the present embodiment, a thermoplastic resin of PC (polycarbonate) resin (Iupizeta EP5000: manufactured by Mitsubishi Gas Chemical Co., Ltd.) is used as the optical substrate 51.

The optical substrate 51 has a resin inflow cut mark 51a (non-axisymmetric part) formed on the side surface of the substrate at the time of injection molding. The excision mark 51a has a different shape from other portions 511 on the same circumference centered on the optical axis O.
In the optical base 51, a flat surface 51b perpendicular to the optical axis O is formed on the outer periphery of the bonding surface 51A. The flat surface 51b is a ring-shaped plane.

  Next, the optical substrate 52 as the second optical substrate has a biconvex lens shape. The optical base 52 has a bonding surface 52A and an anti-bonding surface 52B, each having an optically effective surface. The bonding surface 52A has an aspherical shape with an approximate radius of curvature R2a of R2a = 13 mm. The anti-bonding surface 52B has an aspherical shape with an approximate curvature radius R2b of R2b = 25 mm.

The optical base 52 is a plastic molded lens having a center thickness t2 of t2 = 5 mm and an outer diameter D2 of D2 = φ10 mm.
In the present embodiment, a thermoplastic resin of PMMA (acrylic) resin (Delpet 80N: manufactured by Asahi Kasei Chemicals Corporation) is used as the optical substrate 52.
This optical base material 52 has a resin inflow cut mark 52a (non-axisymmetric part) formed on the side surface of the base material at the time of injection molding. The excision mark 52a has a different shape from other portions 521 on the same circumference centered on the optical axis O.

  FIG. 27 is a cross-sectional view of a bonded optical element 50 formed by bonding two optical substrates 51 and 52 together.

  In FIG. 27, the optical base material 51 and the optical base material 52 are arranged so that the excision mark 51a of the optical base material 51 and the excision mark 52a of the optical base material 52 do not coincide with each other. In the present embodiment, the arrangement where the center of the excision mark 51a and the center of the excision mark 52a coincide with each other is set to 0 °, and the optical axis O between the excision marks 51a and 52a is rotated. The angle θ in the rotation direction was arranged to be 180 °.

The angle θ is not limited to 180 °. It is only necessary that the optical bases be arranged so that at least a part of one excision mark does not overlap (does not match) the other excision mark when viewed from the optical axis ◯ direction. For example, it is preferable that the overlapping range when viewed from the direction of the optical axis O is not more than half of the region of the cut mark 51a and the cut mark 52a of the optical base material 52.
In the present embodiment, the excision marks are arranged at positions where the angles in the rotation direction about the optical axis are substantially equal. Therefore, the overlapping range when the cut mark 51a of the optical base material 51 and the cut mark 52a of the optical base material 52 are viewed from the direction of the optical axis O is zero.

27, when the optical base materials 51 and 52 are bonded together, the thermosetting resin 6 sandwiched between the optical base materials 51 and 52 is cured to obtain the bonded optical element 50. Yes. Here, the resin thickness of the bonded optical element 50 formed by bonding the two optical substrates 51 and 52 is the center resin thickness t0 = 0.8 mm, and the resin thickness t3 at the optically effective diameter D0 (φ15 mm) of the resin layer = It is 0.2 mm.
(Lamination method)

Next, a bonding method will be described.
FIG. 28 is a diagram showing a schematic flowchart of the present embodiment.
At the time of bonding, the optical base 51 is placed down, the optical base 52 is placed up, and the bonding surfaces 51A and 52A are positioned facing each other at a predetermined distance in the optical axis O direction (S51 in FIGS. 26 and 28). ).

  Next, in a state where the optical base materials 51 and 52 are vacuum-sucked, the excision mark 51a of the optical base material 51 and the excision mark 52a of the optical base material 52 have an angle θ in the rotation direction about the optical axis O. The optical base 51 and the optical base 52 are arranged so as not to coincide.

In the present embodiment, the arrangement in which the center of the excision mark 51a of the optical base material 51 and the center of the excision mark 52a of the optical base material 52 coincide with each other is set to 0 °, and is rotated about the optical axis O, so that the excision mark 51a, The optical base material 51 and the optical base material 52 are arranged so that the angle θ in the rotation direction about the optical axis O between 52a is 180 ° (S52 in FIG. 28).
Next, a desired amount of a curable resin (the thermosetting resin 6 in the present embodiment) is discharged onto the bonding surface 51A of the optical substrate 51 (S53 in FIGS. 26 and 28).

Thereafter, the optical base 51 and the optical base 52 are moved relatively close to each other in the optical axis O direction until the resin thickness reaches a desired thickness by the bonding surface 52A of the optical base 52, and the thermosetting resin 6 is moved. It is extended (S54 in FIG. 28).
While maintaining this state, the resin layer is cured by placing in a heating furnace and heating at a predetermined temperature for a predetermined time (S55 in FIGS. 27 and 28). Thereby, the bonded optical element 50 was obtained.

  Since the two optical base materials 51 and 52 have the cut marks 51a and 52a (non-axisymmetric portions), the rigidity of the optical base materials 51 and 52 becomes non-axisymmetric. Axisymmetric. Further, in the plastic molded lens, since transfer pressure is applied from the excision marks 51a and 52a as the resin inflow ports, the residual stress is increased around the excision marks 51a and 52a, and the non-axisymmetric deformation is further increased.

As described above, in the vicinity of the large excision marks 51a and 52a, when the thermosetting resin 6 is cured, non-axisymmetric deformation occurs due to the curing shrinkage, and the shape accuracy of the optically effective surface may be deteriorated.
According to the present embodiment, the optical base materials 51 and 52 are bonded so that the excision marks 51a and 52a at the resin inlet do not overlap each other in the optical axis O direction. Can be small.

[Embodiment 6]

  FIG. 29 is a cross-sectional view of the three optical substrates 61, 62, and 63 to be bonded together in the sixth embodiment. 30 is a plan view of the optical substrate 61, FIG. 31 is a plan view of the optical substrate 62, and FIG. 32 is a plan view of the optical substrate 63. 33 is a cross-sectional view of a state in which two optical substrates 61 and 62 are bonded together, and FIG. 34 is a state in which the optical axes of the intermediate composite optical element 60 ′ and the optical substrate 63 are aligned and face each other. FIG.

In FIG. 29, an optical substrate 61 as a first optical substrate has a biconcave lens shape. The optical base 61 has a bonding surface 61A and an anti-bonding surface 61B each having an optically effective surface.
The bonding surface 61A has an aspherical shape with an approximate curvature radius R1a of R1a = 8 mm. The anti-bonding surface 61B has an aspherical shape with an approximate radius of curvature R1b of R1b = 38 mm.

The optical substrate 61 is a plastic molded lens having a center thickness t1 of t1 = 0.8 mm and an outer diameter D1 of D1 = φ12.4 mm.
In the present embodiment, a thermoplastic resin of COP (cycloolefin polymer) resin (ZEONEX 480R: manufactured by Nippon Zeon Co., Ltd.) is used as the optical substrate 61.
As shown in FIG. 30, the optical base 61 has a cut part 61a (non-axisymmetric part) in which a part of a circular lens in plan view is cut off by a straight line 611a. The cut portion 61a has a shape different from that of the other portion 611 on the same circumference around the optical axis O.

  Further, the optical base 61 has a flat surface 61b perpendicular to the optical axis O formed on the outer periphery of the bonding surface 61A (see FIG. 29). The flat surface 61b is a ring-shaped plane excluding the cut portion 61a (see FIG. 30).

  Similarly, a flat surface 61c perpendicular to the optical axis O is formed on the outer periphery of the anti-bonding surface 61B.

Next, the optical substrate 62 as the second optical substrate has a convex meniscus lens shape. The optical substrate 62 has a bonding surface 62A and a bonding surface 62B each having an optically effective surface. The bonding surface 62A has an aspherical shape with an approximate curvature radius R2a of R2a = 6.4 mm. The anti-bonding surface 62B has an aspherical shape with an approximate curvature radius R2b of R2b = 16 mm.
This optical substrate 62 is a plastic molded lens having a center thickness t2 of t2 = 2.4 mm and an outer diameter D2 of D2 = φ12.4 mm.

In the present embodiment, a thermoplastic resin of PC (polycarbonate) resin (Iupizeta EP5000: manufactured by Mitsubishi Gas Chemical Co., Ltd.) is used as the optical substrate 62.
As shown in FIG. 31, the optical base 62 has a cut part 62a (non-axisymmetric part) in which a part of a circular lens in plan view is cut off by a straight line 621a. The cut part 62a has a shape different from that of the other part 621 on the same circumference around the optical axis O.

In the optical base 62, a flat surface 62b perpendicular to the optical axis O is formed on the outer periphery of the bonding surface 62A (see FIG. 29).
Similarly, a flat surface 62c perpendicular to the optical axis O is formed on the outer periphery of the bonding surface 62B. Moreover, the flat surfaces 62b and 62c are ring-shaped planes excluding the cut portion 62a (see FIGS. 29 and 31).

Next, the optical substrate 63 as the third optical substrate has a biconvex shape. The optical substrate 63 has a bonding surface 63A and an anti-bonding surface 63B. The bonding surface 63A has an aspherical shape with an approximate radius of curvature R3a of R3a = 20 mm. The anti-bonding surface 63B has an aspherical shape with an approximate curvature radius R3b of R3b = 80 mm.
The optical base 63 is a plastic molded lens having a center thickness t3 of t3 = 2.4 mm and an outer diameter D3 of D3 = φ12.4 mm.

In the present embodiment, a thermoplastic resin of PMMA (acrylic) resin (Delpet 80N: manufactured by Asahi Kasei Chemicals Corporation) is used as the optical substrate 63.
As shown in FIG. 32, the optical base 63 has a cut part 63a (non-axisymmetric part) in which a part of a circular lens in plan view is cut off by a straight line 631a. The cut part 63a has a shape different from that of the other part 631 on the same circumference.

The optical base 63 has a flat surface 63b perpendicular to the optical axis O formed on the outer periphery of the bonding surface 63A. The flat surface 63b is a ring-shaped plane excluding the cut portion 63a.
Similarly, a flat surface 63c perpendicular to the optical axis O is formed on the outer periphery of the anti-bonding surface 63B.

As shown in FIG. 33, when the cut portions 61a and 62a of the two optical base members 61 and 62 are viewed from the optical axis ◯ direction, at least a part of one cut portion overlaps with the other cut portion. Rotate around the optical axis O so as not to coincide (so as not to coincide with each other), position and bond to obtain an intermediate composite optical element 60 ′.
Further, as shown in FIG. 34, the intermediate composite optical element 60 ′ and the optical base 63 are arranged to face each other with the optical axis O aligned, and the intermediate composite optical element 60 ′ and the optical base 63 are bonded together.

  At this time, the arrangement in which the centers of the respective cut portions coincide with each other so that the respective cut portions 61a, 62a, 63a do not overlap in the optical axis O direction is set to 0 °. The angle θ in the rotation direction is shifted by 120 ° with respect to the optical axis O (see FIG. 36). Thereby, in this Embodiment, the overlapping range when it sees from the optical axis O direction of each cut part 61a, 62a, 63a is zero.

Further, as shown in FIG. 35, the optical bases 61 and 62 and the ultraviolet curable resin 4 sandwiched between the optical bases 62 and 63 are cured to obtain the bonded optical element 60.
Here, in the bonding optical element 60, the resin layer between the optical substrate 61 and the optical substrate 62 has a resin thickness at the center resin thickness t0 = 0.2 mm and the optical effective diameter D0 (φ8.8 mm) of the resin layer. t3 = 0.8 mm. The resin layer between the optical substrate 62 and the optical substrate 63 has a center resin thickness t0 ′ = 0.8 mm, and a resin thickness t3 ′ = 0.4 mm at the optical effective diameter D0 (φ8.8 mm) of the resin layer. Met.
(Lamination method)

FIG. 35 is a cross-sectional view of the bonded optical element 60 formed by bonding the intermediate composite optical element 60 ′ and the optical base 63. As shown in FIG. FIG. 36 is a plan view thereof. FIG. 37 is a diagram showing a schematic flowchart of the present embodiment.
In the pasting, as described above, first, the optical base 61 and the optical base 62 are pasted to form the intermediate composite optical element 60 ′. Next, the optical base 63 is bonded to the intermediate composite optical element 60 ′. However, it is not limited to this order, For example, after bonding the optical base material 62 and the optical base material 63, you may bond the optical base material 61. FIG.

  In the present embodiment, the optical base 61 is down, the optical base 62 is up, and the bonding surfaces 61A and 62A are positioned so as to face each other at a predetermined distance in the optical axis O direction (see FIGS. 29 and 37). S61).

In this case, the optical base 61 is rotated around the optical axis O so that the cut part 61a of the optical base 61 and the cut part 62a of the optical base 62 do not overlap in the optical axis O direction. In the present embodiment, the arrangement in which the center of the cut part 61a and the center of the cut part 62a coincide with each other is set to 0 °, and the optical axis O is rotated. Thus, the optical base 61 and the optical base 62 are positioned and arranged so that the angle θ between the cut portions 61a and 62a in the rotation direction about the optical axis O is 120 ° (FIG. 36). , S62 in FIG.
Further, a desired amount of curable resin (ultraviolet curable resin 4 in the present embodiment) is discharged onto the bonding surface 62A of the optical substrate 62 (S63 in FIGS. 29 and 37). In addition, you may perform discharge of this ultraviolet curable resin 4 before positioning the optical base material 61 and the optical base material 62. FIG.

Thereafter, the optical base 61 and the optical base 62 are moved relatively close to each other in the optical axis O direction until the resin thickness reaches a desired thickness by the bonding surface 62A of the optical base 62, and the ultraviolet curable resin 4 is pressed. (S64 in FIGS. 33 and 37).
While maintaining this state, ultraviolet rays are irradiated by the ultraviolet lamp 5 through the optical substrate 61 to cure the resin layer (S65 in FIGS. 33 and 37). In addition, you may irradiate an ultraviolet-ray through the optical base material 62. FIG. The ultraviolet rays at this time have a mountain-shaped illuminance distribution with a central illuminance of 25 ± ² mW / cm ² and a peripheral illuminance of 10 ± ² mW / cm ² . After irradiation with such ultraviolet rays for 20 seconds, ultraviolet rays having an almost uniform illuminance distribution with an illuminance of 200 ± 5 mW / cm ² are further irradiated for 100 seconds.

  Thus, as described above, the optical base 61 and the optical base 62 joined together are referred to as an intermediate composite optical element 60 'for convenience (see FIG. 33).

Subsequently, the cut portions 61a and 62a in the intermediate composite optical element 60 ′ and the cut portion 63a of the optical base 63 are rotated around the optical axis O so as not to overlap when viewed from the optical axis direction.
In the present embodiment, the arrangement in which the centers of the respective cut portions coincide with each other is set to 0 °, and the respective cut portions 61a, 62a, and 63a are rotated about the optical axis O. Thereby, the optical base materials 61, 62, and 63 are positioned and arranged so that the angle θ in the rotation direction about the optical axis O between the respective cut portions 61a, 62a, and 63a is 120 ° ( S66 in FIGS. 36 and 37).

  Further, a desired amount of curable resin (ultraviolet curable resin 4 in the present embodiment) is discharged onto the bonding surface 62B of the optical base 62 in the intermediate composite optical element 60 '(S67 in FIGS. 34 and 37). The discharging process of the ultraviolet curable resin 4 may be performed before the intermediate composite optical element 60 ′ and the optical base 63 are positioned.

  Next, the intermediate composite optical element 60 ′ and the optical base 63 are moved relatively close to each other in the direction of the optical axis O until the resin thickness reaches a desired thickness by the bonding surface 63A of the optical base 63, and an ultraviolet curable resin is obtained. 4 is stretched (S68 in FIGS. 35 and 37).

While maintaining this state, ultraviolet rays are irradiated by the ultraviolet lamp 5 through the optical base 63 to cure the resin layer (S69 in FIGS. 35 and 37). In addition, you may irradiate an ultraviolet-ray through intermediate | middle composite optical element 60 '.
The ultraviolet rays at this time have a mountain-shaped illuminance distribution with a central illuminance of 25 ± ² mW / cm ² and a peripheral illuminance of 10 ± ² mW / cm ² . After irradiation with such ultraviolet rays for 20 seconds, ultraviolet rays having an almost uniform illuminance distribution with an illuminance of 200 ± 5 mW / cm ² are further irradiated for 100 seconds. Thereby, the bonded optical element 60 was obtained.

  When three optical base materials are stacked to form a bonding element, when the cut portions 61a, 62a, 63a (non-axisymmetric portions) of the three optical base materials 61, 62, 63 are viewed from the optical axis O direction, If they are overlapped, the portions where the surface accuracy of the optically effective surface deteriorates due to non-axisymmetric deformation at the time of curing shrinkage of the resin layer overlap. For this reason, optical performance deteriorates. However, in the present embodiment, since the portion where the surface accuracy may be deteriorated is not overlapped when viewed from the direction of the optical axis O, the influence on the deterioration of the optical performance can be reduced.

4 UV curable resin 5 UV lamp 6 Thermosetting resin 10, 20, 30, 40, 50, 60 Composite optical element 60 'Intermediate composite optical element 11, 12, 21, 22, 31, 32, 41, 42, 51 , 52, 61, 62, 63 Optical substrates 11A, 12A, 21A, 22A, 31A, 32A, 41A, 42A, 51A, 52A, 61A, 62A, 62B, 63A Bonding surfaces 11B, 12B, 21B, 22B, 31B , 32B, 41B, 42B, 51B, 52B, 61B, 63B Anti-bonding surfaces 11a, 12a, 21a, 22a, 31a, 32a, 61a, 62a, 63a Cut portions 41a, 42a Abutting portions 51a, 52a Cutting marks 11b, 21b, 31b, 41b, 61b, 61c, 62b, 62c, 62b, 63b, 63c Flat surface 13a Overlapping range 4a, 14b Gaps 111, 121, 211, 221, 311, 321, 411, 421, 511, 521, 611, 621, 631 Other parts 111a, 121a, 211a, 221a, 311a, 321a, 611a on the circumference , 621a, 631a Straight line 71, 72 Base material holding part

Claims (6)

A composite optical element in which at least two optical substrates are bonded with a curable resin,
Each of the at least two optical bases includes a non-axisymmetric part formed on a part other than the optically effective surface and having a shape different from that of the other part on the same circumference, and each of the non-axisymmetric parts. A composite optical element, wherein when viewed from the optical axis direction, at least part of one non-axisymmetric part is arranged not to overlap the other non-axisymmetric part. 2. The composite optical element according to claim 1, wherein, when each of the non-axisymmetric portions is viewed from the optical axis direction, a range in which the non-axisymmetric portions overlap each other is half or less of a region of one of the non-axisymmetric portions. . 3. The composite optical element according to claim 1, wherein each of the non-axisymmetric portions is arranged at a position where angles in a rotation direction about the optical axis are substantially equal. A curable resin comprising a first optical base and a second optical base, each having a non-axisymmetric portion formed on a portion other than the optically effective surface and having a different shape from other portions on the same circumference. A method of manufacturing a composite optical manufacturing element to be bonded by:
Discharging the curable resin to the first optical substrate;
When the non-axisymmetric part of the first optical base and the non-axisymmetric part of the second optical base are viewed from the optical axis direction, at least a part of one non-axisymmetric part is A step of positioning the optical bases so as not to overlap with the non-axisymmetric part;
Stretching the curable resin with the second optical substrate;
And a step of curing the curable resin. A method of manufacturing a composite optical element, comprising: In the step of positioning the optical base materials, when the respective non-axisymmetric portions are viewed from the optical axis direction, the overlapping range is not more than half of the region of each of the non-axisymmetric portions. The method of manufacturing a composite optical element according to claim 4, wherein positioning is performed. In the step of positioning the optical substrates,
5. The method of manufacturing a composite optical element according to claim 4, wherein each of the non-axisymmetric portions is positioned so that angles in a rotation direction about the optical axis are substantially equal.

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