JPWO2007145116A1 - Composite optical element and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a composite optical element and a method for manufacturing the same, and more particularly to a composite optical element in which a second optical unit is bonded to a part of a first surface of a first optical unit. Improve optical properties. In the composite optical element (1), spacer members (7, 7,...) Are fixed to the composite optical element body (15). The composite optical element body (15) includes a first optical unit (10) and a second optical unit (20), and a lens surface is provided on the first surface (13) of the first optical unit (10). (11) and a first outer peripheral surface portion (12) surrounding the lens surface (11) and connected to the lens surface (11). The second optical unit (20) is bonded to the first optical unit (10) at the lens surface (11). The spacer members (7, 7,...) Are fixed to the first outer peripheral surface portion (12).

Description

  The present invention relates to a composite optical element and a method for manufacturing the same, and more particularly to a composite optical element in which a second optical unit is bonded to a part of a first surface of a first optical unit.

  Conventionally, a composite optical element in which two or more optical parts are bonded to each other is known. For example, in a composite optical element composed of two optical parts, the second optical part is bonded to the first optical part on the surface of the first optical part. Such a composite optical element is formed after the first optical part is molded. It can be manufactured by bonding the second optical part to the first optical part.

In such a composite optical element, the shape of each optical part may greatly affect the optical characteristics of the composite optical element. Therefore, in Patent Document 1, when a composite optical element composed of two optical parts is molded, the second optical part is positioned on the first optical part using a pulse motor or a mechanism with less backlash (spring pressing). A method of joining is disclosed.
JP 2001-249208 A

  However, even if the method described in Patent Document 1 is used, the second optical unit may not be formed into a desired shape, and as a result, a composite optical element having excellent optical characteristics may not be provided.

  The present invention has been made in view of such points, and an object thereof is to improve the optical characteristics of the composite optical element.

  In the composite optical element of the present invention, the spacer member is fixed to the composite optical element body. The composite optical element body includes a first optical part having a first optical functional surface part and a first outer peripheral surface part surrounding the first optical functional surface part and connected to the first optical functional surface part on the first surface; And a second optical unit bonded to the first optical unit in the one optical function surface unit. The spacer member is fixed to the first outer peripheral surface portion.

  The second optical unit may be bonded to the first optical unit on the entire first surface. In this case, the spacer member may be embedded in the second optical unit. You may expose from the surface (2nd outer peripheral surface part).

  The method for producing a composite optical element of the present invention is a method for producing a composite optical element by joining a second optical member and a spacer member to a first optical member. Specifically, a first optical member having a first optical functional surface portion and a first outer peripheral surface portion surrounding the first optical functional surface portion and connected to the first optical functional surface portion is prepared on the first surface. A step (a), a step (b) of preparing a molding die having a molding surface portion for molding the second optical member, and a molding surface outer peripheral portion surrounding the molding surface portion and connected to the molding surface portion; A step (c) of disposing a spacer member on the outer periphery, and a step (d) of setting an optical material as a material of the second optical member on the molding surface and pressing the first optical member against the optical material. I have. In the step (d), after the first optical functional surface portion is brought into contact with the optical material and the first optical member is disposed on the mold, the first optical member is used as the optical material until the first outer peripheral surface portion contacts the spacer member. The optical material is pressed and bonded to at least the first optical function surface portion.

  According to the present invention, optical characteristics can be improved.

FIG. 1A is a cross-sectional view of the composite optical element according to Embodiment 1, and FIG. 1B is a plan view of the composite optical element as viewed from below in FIG. 2A to 2D are cross-sectional views illustrating a method for molding a composite optical element according to the first embodiment. FIG. 3 is a plan view when the lower mold is viewed from above in FIG. FIG. 4 is a cross-sectional view of a composite optical element according to Modification 1 of Embodiment 1. FIG. 5 is a cross-sectional view of a composite optical element according to Modification 2 of Embodiment 1. FIG. 6 is a cross-sectional view of a composite optical element according to Modification 3 of Embodiment 1. FIG. 7 is a cross-sectional view of a composite optical element according to Modification 4 of Embodiment 1. FIG. 8 is a cross-sectional view of a composite optical element according to Modification 5 of Embodiment 1. FIG. 9A is a cross-sectional view of the composite optical element according to the second embodiment, and FIG. 9B is a plan view of the composite optical element as viewed from below in FIG. FIG. 10 is a cross-sectional view of a composite optical element according to the third embodiment. FIGS. 11A and 11B are cross-sectional views illustrating a part of the composite optical element molding method according to the third embodiment.

Explanation of symbols

1, 2, 3, 101, 201, 301, 401, 501 Compound optical element 7 Spacer member (first spherical member)
8 Spacer member (second sphere member)
10,210 1st optical part 11 Lens surface (1st optical function surface part)
11a Concave and convex portion 12 First outer peripheral surface portion 13 First surface 15 Composite optical element body 20, 30, 220 Second optical portion 33 Second outer peripheral surface portion 61 First optical member 70 Resin preform (optical material)
71 2nd optical member 91,94 Mold 91a, 94a Molding surface part 91b, 94b Molding surface outer peripheral part 94c Concave part

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

Embodiment 1 of the Invention
In the first embodiment, as a specific example of the composite optical element, a composite lens is taken as an example, and the configuration and the molding method thereof are shown.

  FIG. 1 is a diagram showing a configuration of a composite optical element 1 according to the present embodiment, FIG. 1 (a) is a schematic sectional view thereof, and FIG. 1 (b) is a composite optical element from below in FIG. 1 (a). FIG.

  In the composite optical element 1 according to the present embodiment, four spacer members (first sphere members) 7, 7,... Are fixed to the composite optical element body 15. The composite optical element body 15 is made of glass. It has the 1st optical part 10 and the 2nd optical part 20 made from resin. A lens surface (first optical function surface portion) 11 and a first outer peripheral surface portion 12 exist on the first surface 13 of the first optical portion 10, and the first outer peripheral surface portion 12 surrounds the lens surface 11. It is connected to the lens surface 11. That is, the 1st outer peripheral surface part 12 is the surface of an edge part (not shown). And the 2nd optical part 20 is joined to the lens surface 11, and the spacer members 7, 7, ... are being fixed to the 1st outer peripheral surface part 12. As shown in FIG. The spacer members 7, 7,... Are for controlling the shape of the second optical unit 20 during molding, for example, for adjusting the thickness of the second optical unit 20 on the lens surface 11.

  The composite optical element 1 concerning this embodiment is shown in detail. On the lens surface 11 of the first optical unit 10, the periphery of the optical axis is smoothly formed, while the concavo-convex portion 11 a is formed on the periphery. The uneven portion 11a is formed in a sawtooth shape in cross section and functions as a diffraction portion. As described above, since the lens surface 11 of the first optical unit 10 includes two regions having different optical powers, the composite optical element 1 according to the present embodiment collects two lights having different wavelengths. Can do. The first optical unit 10 has another lens surface 14 on the side opposite to the lens surface 11, but the lens surface 14 is formed smoothly.

  The second optical unit 20 is bonded to the first optical unit 10 on the lens surface 11 as described above, and has the lens surface 21 on the opposite side to the bonded surface 22. The lens surface 21 is smoothly molded.

  Each of the spacer members 7, 7,... Is a sphere made of glass, and is disposed on the first outer peripheral surface portion 12. Specifically, the spacer members 7, 7,... Are arranged at equal intervals on a circumference existing on the first outer peripheral surface portion 12 with one point on the optical axis of the first optical unit 10 as the center. Since the spacer member is arranged in this way, when the composite optical element 1 is manufactured using the pressing method, the wobble of the first optical member 61 (described in FIG. 2A) during the pressing process is prevented. can do.

  The arrangement of the spacer members 7, 7,... On the first outer peripheral surface portion 12 is not limited to the arrangement shown in FIG. The wobbling of the first optical member 61 can be prevented by disposing it on the side opposite to the spacer member.

  As described above, since the composite optical element 1 according to this embodiment includes the spacer members 7, 7,..., The composite optical element 1 is molded while controlling the shape of the second optical unit 20 as described later. can do. Therefore, the composite optical element 1 according to the present embodiment exhibits optical characteristics (such as aberration and light collection rate) superior to those of the composite optical element manufactured without controlling the second optical unit.

  2A to 2D are cross-sectional views illustrating a method for molding the composite optical element 1 according to the present embodiment. FIG. 3 is a plan view of the mold 91 as viewed from above in the process shown in FIG. In the molding method of the composite optical element 1 according to the present embodiment, after molding the first optical member 61 to be the first optical unit 10 in the steps shown in FIGS. 2A and 2B, In the step shown in (d), the second optical member 71 to be the second optical unit 20 is joined to the first optical member 61. This is specifically shown below.

  First, as shown in FIG. 2A, a glass preform 60 and a molding apparatus are prepared. The glass preform 60 preferably has a shape very similar to the shape of the first optical unit 10. The molding apparatus has an upper mold 81 and a lower mold 82, and the upper mold 81 and the lower mold 82 have molding surfaces 81a and 82a, respectively. Since the molding surface 81a is a surface for molding the lens surface 14 of the first optical unit 10, it is formed smoothly. On the other hand, since the molding surface 82a is a surface for molding the lens surface 11 of the first optical unit 10, the center of the surface is smooth, while the peripheral edge of the surface is irregular corresponding to the irregular portion 11a. Then, the glass preform 60 is set in a cavity formed by the molding surface 81a and the molding surface 82a.

  Next, the glass preform 60 is heated to near the glass softening temperature, and is pressed as shown in FIG. 2B to form the molding surfaces 81a and 82a of the upper mold 81 and the lower mold 82, respectively. Transfer to the surface. When pressing, the upper mold 81 may be pressed against the surface of the glass preform 60, the lower mold 82 may be pressed against the surface of the glass preform 60, and the upper mold 81 and the lower mold 82 are pressed against the glass preform 60. May be. Then, it is cooled. Thereby, the 1st optical member 61 can be shape | molded. Since the first optical member 61 is molded using the press molding method in this manner, the first optical member 61 is molded by a single molding, unlike when the first optical member is molded using the polishing method or the grinding method. In addition, even if the lens surface is aspherical, it can be molded relatively easily by processing the molding surface.

  Then, the shaping | molding apparatus shown in FIG.2 (c) is prepared. The molding apparatus has a lower mold 91, and a molding surface portion 91 a is formed on the lower mold 91. The molding surface portion 91a is formed for molding the lens surface 22 of the second optical unit 20, and a molding surface outer peripheral portion 91b exists outside the molding surface portion 91a. The spacer members 7, 7,... Are set on the molding surface outer peripheral portion 91b. Specifically, as shown in FIG. 3, the four spacer members 7, 7,... Deploy. Further, the molten resin preform 70 is set on the molding surface portion 91a.

  Then, as shown in FIG. 2D, the first optical member 61 is pressed against the lower mold 91 and pressed. Specifically, first, the lens surface of the first optical member 61 is brought into contact with the surface of the resin preform 70 with the optical axis of the first optical member 61 aligned with the central axis of the molding surface portion 91a. Thus, by arranging the first optical member 61 on the lower mold 91 with the optical axis aligned with the central axis, the second optical member 71 can be joined to the first optical member 61 with the optical axes aligned with each other. it can. Next, the first optical member 61 is pressed against the resin preform 70. As the first optical member 61 is pressed against the resin preform 70, the molten resin flows from the center of the molding surface portion 91a toward the periphery thereof. When the first outer peripheral surface portion of the first optical member 61 comes into contact with the spacer members 7, 7,. Thereby, the composite optical element 1 shown to Fig.1 (a) can be shape | molded.

  As described above, in the molding method of the composite optical element 1 according to the present embodiment, the first outer periphery of the first optical member 61 in the step of bonding the second optical member 71 (the step shown in FIG. 2D). Since the 1st optical member 61 is pressed until a surface part contact | abuts to the spacer members 7, 7, ..., the thickness of the 2nd optical member 71 joined to the 1st optical member 61 is controllable.

  Such a composite optical element 1 can be mounted on an optical apparatus such as an imaging device, an illumination device, and an optical disc recording / reproducing device. The imaging device is a device for photographing a subject, for example, a digital still camera or a digital video camera. The illumination device is a device for irradiating light on an object to be illuminated, and is, for example, a projector. In addition, the optical disc recording / reproducing apparatus records and reproduces digital versatile discs (hereinafter referred to as DVD), compact discs (hereinafter referred to as CD), Blu-ray discs (registered trademark, hereinafter referred to as BD (registered trademark)), and the like. It is a device to do. In general, DVD, CD, and BD have different light source wavelengths and optical disk thicknesses for recording and reproduction, so that a single optical disk recording and reproduction device can record and reproduce DVD, CD, and BD. Although it is necessary to devise an optical system, if the composite optical element 1 according to the present embodiment is used, an optical disc recording / reproducing apparatus compatible with a plurality of types of information recording media can be realized.

  In addition, the shape of the composite optical element body and the shape of the concavo-convex portion are not limited to the above description. In the following first and fifth modified examples, modified examples of these shapes will be shown.

(First modification)
FIG. 4 is a schematic cross-sectional view of the composite optical element 101 according to the first modification of the first embodiment. In the composite optical element 101 according to this modified example, the uneven portion 121 a is formed not only on the lens surface 11 of the first optical unit 10 but also on the lens surface 121 of the second optical unit 120. As a result, the composite optical element 101 according to the present modification can collect three lights having different wavelengths.

(Second modification)
FIG. 5 is a schematic cross-sectional view of a composite optical element 201 according to the second modification of the first embodiment. In the composite optical element 201 according to this modification, the first optical unit 210 has a flat plate shape, and the uneven portion 211a has a stepped cross section and is a diffractive portion.

  Specifically, on the first surface 213 of the first optical unit 210, as in the first optical unit 10 of the first embodiment, the lens surface 211 and the first outer peripheral surface portion 212 exist, and the lens surface 211 is present. The concavo-convex portion 211a is formed on the surface. The second optical unit 220 is bonded to the first optical unit 210 at the bonding surface 222.

(Third Modification)
FIG. 6 is a schematic cross-sectional view of a composite optical element 301 according to the third modification of the first embodiment. The composite optical element 301 according to this modification is substantially the same as the composite optical element 201 according to the second modification, but the concavo-convex part 311a is a lens array part. That is, a plurality of concave lenses are arranged on the lens surface 311.

(Fourth modification)
FIG. 7 is a schematic cross-sectional view of a composite optical element 401 according to the fourth modification of the first embodiment. The composite optical element 401 according to this modification is substantially the same as the composite optical element 1 according to the first embodiment, but the concavo-convex part 411a is a phase step part.

(Fifth modification)
FIG. 8 is a schematic cross-sectional view of a composite optical element 501 according to a fifth modification of the first embodiment. The composite optical element 501 according to this modification is substantially the same as the composite optical element 1 according to the first embodiment, but the concavo-convex part 511a is an antireflection part. That is, a plurality of cone-shaped protrusions are formed on the lens surface, and the cone-shaped protrusions are arranged at a pitch equal to or less than the wavelength of the light to be reflected.

<< Embodiment 2 of the Invention >>
FIG. 9 is a diagram illustrating a configuration of the composite optical element 2 according to the second embodiment. FIG. 9A is a cross-sectional view thereof, and FIG. 9B is a plan view of the composite optical element 2 as viewed from below in FIG. 9A.

  In the composite optical element 2 according to the present embodiment, the second optical unit 30 is bonded to the first optical unit 10 not only at the lens surface 11 but also at the first outer peripheral surface portion 12. That is, in the composite optical element 2, the second optical unit 30 is bonded to the first optical unit 10 on the first surface 13. Such a composite optical element 2 is formed by the resin preform melted during the pressing process flowing out from the molding surface portion of the mold through the molding surface outer peripheral portion or the first outer peripheral surface portion of the first optical member and solidifying. It is formed if the amount of the resin preform is large.

  Further, three spacer members 7, 7,... Of the first embodiment are fixed to the first outer peripheral surface portion 12, and a spacer member (second sphere) having a smaller sphere diameter than the spacer members 7, 7,. Three members 8 are fixed. .. And the spacer members 8, 8,... Are embedded in the second optical unit 30.

  As described above, in the composite optical element 2 according to the present embodiment, since the second optical unit 30 is also joined to the first outer peripheral surface part 12, the composite optical element 2 is attached to the lens barrel by using this part as an attachment part. It can be attached to the optical system. Further, since the spacer members 7, 7,... And the spacer members 8, 8,... Are embedded in the attachment portion, the strength of the attachment portion can be ensured as compared with the case where the spacer member is not embedded. .

<< Embodiment 3 of the Invention >>
FIG. 10 is a schematic cross-sectional view showing the configuration of the composite optical element 3 according to the third embodiment.

  In the composite optical element 3 according to the present embodiment, the second optical unit 30 is bonded to the first optical unit 10 on the first surface 13 as described in the second embodiment, and the spacer members 7, 7, Are exposed from the second outer peripheral surface portion 33 connected to the lens surface 31. As described above, since the spacer members 7, 7,... Are exposed from the second outer peripheral surface portion 33, the mounting area when the composite optical element 3 is attached to the optical system can be reduced. It is possible to prevent heat generated at times from being transmitted to the composite optical element 3.

  11A and 11B are cross-sectional views showing a part of the method for manufacturing the composite optical element 3 according to the present embodiment.

  After the composite optical element 3 according to the present embodiment has formed the first optical member 61 through the steps shown in FIGS. 2A and 2B in the first embodiment, the composite optical element 3 is shown in FIGS. 11A and 11B. The second optical member 72 is joined to the first optical member 61 through the steps shown in the figure. Below, it demonstrates centering on the manufacturing method peculiar to this embodiment.

  After the first optical member 61 is molded according to the method described in the first embodiment, a molding die 94 shown in FIG. 11A is prepared. The molding die 94 is substantially the same as the molding die 91 of the first embodiment, but four concave portions 94c, 94c,... Are formed on the molding surface outer peripheral portion 94b. Each concave portion 94c is formed, for example, as a V-groove in the outer peripheral portion 94b of the molding surface, and is formed on the circumference centered at one point on the optical axis at intervals. Then, a part of the spacer member is inserted into the recesses 94c, 94c,. Since a part of each spacer member 7 is fitted in the mold 94 in this way, a part of each spacer member 7 is exposed from the second outer peripheral surface portion 33 as shown in FIG. 10 in the molded composite optical element 3.

  Thereafter, the molten resin preform 70 is set on the molding surface portion 94 a and the first optical member 61 is pressed against the resin preform 70. Then, as described in the first embodiment, when the first outer peripheral surface portion of the first optical member 61 comes into contact with the spacer members 7, 7,.

  In addition, the shape of the said recessed part is not limited to a V-groove. The recessed part should just be a structure which can insert a part of each spacer member.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the first to third embodiments.

  The second optical unit may be joined to the first optical unit only on the lens surface of the first optical unit as described in the first embodiment, and the first optical unit as described in the second and third embodiments. It may be joined to the entire first surface of the part, or may be joined to the first optical part at the lens surface of the first optical part and its peripheral edge. The second optical part is shaped so as to be bonded at least on the lens surface of the first optical part, although it cannot be generally stated because it differs depending on the amount of resin preform to be supplied and how to apply pressure during pressing. The

  Although the lens surface of the first optical unit is an aspherical surface, it may be a flat surface as described in the second and third modifications of the first embodiment, and includes a spherical surface, a cylindrical surface, a ball striking surface, and It may be a toric surface.

  Although the second optical part is made of resin, specifically, it is an energy curable resin or a thermoplastic resin. The energy curable resin is, for example, a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or the like, and is a resin that is cured by applying predetermined energy (heat, ultraviolet ray, electron beam, or the like). Therefore, when the second optical part is molded using the energy curable resin, the melted resin is set on the molding surface part of the lower mold, and then the first optical member is pressed to give predetermined energy. For example, when the second optical part is molded using an ultraviolet curable resin, it may be cured by irradiating with ultraviolet rays. In addition, when the second optical part is molded using a thermoplastic resin, the molten resin may be set on the uneven part of the lower mold and then cooled by pressing the first optical member. The timing for applying the predetermined energy and the timing for cooling are both when the first outer peripheral surface portion of the first optical member is in contact with the spacer member.

  The materials of the first and second optical parts are not limited to the above materials. Any of the materials may be glass or resin. The first and second optical units may be mixed with impurities that do not affect the optical characteristics.

  The uneven portion may be formed only on the lens surface of the second optical unit, or two or more types may be formed on each of the lens surface of the first optical unit and the lens surface of the second optical unit.

  The shape and the number of spacer members are not particularly limited.

  In addition, the second optical member is molded using the molten resin preform, but the second optical member may be molded using a resin preform that is liquid at room temperature. The second optical member may be molded by setting in a mold and then melting the resin preform by heating or ultraviolet irradiation.

  As described above, the present invention can be mounted on an optical disc recording / playback apparatus, and can also be mounted on an imaging apparatus (digital still camera, digital video camera, etc.) or display apparatus (projector, etc.). .

  The present invention relates to a composite optical element and a method for manufacturing the same, and more particularly to a composite optical element in which a second optical unit is bonded to a part of a first surface of a first optical unit.

  Conventionally, a composite optical element in which two or more optical parts are bonded to each other is known. For example, in a composite optical element composed of two optical parts, the second optical part is bonded to the first optical part on the surface of the first optical part. Such a composite optical element is formed after the first optical part is molded. It can be manufactured by bonding the second optical part to the first optical part.

In such a composite optical element, the shape of each optical part may greatly affect the optical characteristics of the composite optical element. Therefore, in Patent Document 1, when a composite optical element composed of two optical parts is molded, the second optical part is positioned on the first optical part using a pulse motor or a mechanism with less backlash (spring pressing). A method of joining is disclosed.
JP 2001-249208 A

  However, even if the method described in Patent Document 1 is used, the second optical unit may not be formed into a desired shape, and as a result, a composite optical element having excellent optical characteristics may not be provided.

  The present invention has been made in view of such points, and an object thereof is to improve the optical characteristics of the composite optical element.

  In the composite optical element of the present invention, the spacer member is fixed to the composite optical element body. The composite optical element body includes a first optical part having a first optical functional surface part and a first outer peripheral surface part surrounding the first optical functional surface part and connected to the first optical functional surface part on the first surface; And a second optical unit bonded to the first optical unit in the one optical function surface unit. The spacer member is fixed to the first outer peripheral surface portion.

  The second optical unit may be bonded to the first optical unit on the entire first surface. In this case, the spacer member may be embedded in the second optical unit. You may expose from the surface (2nd outer peripheral surface part).

  The method for producing a composite optical element of the present invention is a method for producing a composite optical element by joining a second optical member and a spacer member to a first optical member. Specifically, a first optical member having a first optical functional surface portion and a first outer peripheral surface portion surrounding the first optical functional surface portion and connected to the first optical functional surface portion is prepared on the first surface. A step (a), a step (b) of preparing a molding die having a molding surface portion for molding the second optical member, and a molding surface outer peripheral portion surrounding the molding surface portion and connected to the molding surface portion; A step (c) of disposing a spacer member on the outer periphery, and a step (d) of setting an optical material as a material of the second optical member on the molding surface and pressing the first optical member against the optical material. I have. In the step (d), after the first optical functional surface portion is brought into contact with the optical material and the first optical member is disposed on the mold, the first optical member is used as the optical material until the first outer peripheral surface portion contacts the spacer member. The optical material is pressed and bonded to at least the first optical function surface portion.

  According to the present invention, optical characteristics can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

Embodiment 1 of the Invention
In the first embodiment, as a specific example of the composite optical element, a composite lens is taken as an example, and the configuration and the molding method thereof are shown.

  FIG. 1 is a diagram showing a configuration of a composite optical element 1 according to the present embodiment, FIG. 1 (a) is a schematic sectional view thereof, and FIG. 1 (b) is a composite optical element from below in FIG. 1 (a). FIG.

  In the composite optical element 1 according to the present embodiment, four spacer members (first sphere members) 7, 7,... Are fixed to the composite optical element body 15. The composite optical element body 15 is made of glass. It has the 1st optical part 10 and the 2nd optical part 20 made from resin. A lens surface (first optical function surface portion) 11 and a first outer peripheral surface portion 12 exist on the first surface 13 of the first optical portion 10, and the first outer peripheral surface portion 12 surrounds the lens surface 11. It is connected to the lens surface 11. That is, the 1st outer peripheral surface part 12 is the surface of an edge part (not shown). And the 2nd optical part 20 is joined to the lens surface 11, and the spacer members 7, 7, ... are being fixed to the 1st outer peripheral surface part 12. As shown in FIG. The spacer members 7, 7,... Are for controlling the shape of the second optical unit 20 during molding, for example, for adjusting the thickness of the second optical unit 20 on the lens surface 11.

  The composite optical element 1 concerning this embodiment is shown in detail. On the lens surface 11 of the first optical unit 10, the periphery of the optical axis is smoothly formed, while the concavo-convex portion 11 a is formed on the periphery. The uneven portion 11a is formed in a sawtooth shape in cross section and functions as a diffraction portion. As described above, since the lens surface 11 of the first optical unit 10 includes two regions having different optical powers, the composite optical element 1 according to the present embodiment collects two lights having different wavelengths. Can do. The first optical unit 10 has another lens surface 14 on the side opposite to the lens surface 11, but the lens surface 14 is formed smoothly.

  The second optical unit 20 is bonded to the first optical unit 10 on the lens surface 11 as described above, and has the lens surface 21 on the opposite side to the bonded surface 22. The lens surface 21 is smoothly molded.

  Each of the spacer members 7, 7,... Is a sphere made of glass, and is disposed on the first outer peripheral surface portion 12. Specifically, the spacer members 7, 7,... Are arranged at equal intervals on a circumference existing on the first outer peripheral surface portion 12 with one point on the optical axis of the first optical unit 10 as the center. Since the spacer member is arranged in this way, when the composite optical element 1 is manufactured using the pressing method, the wobble of the first optical member 61 (described in FIG. 2A) during the pressing process is prevented. can do.

  The arrangement of the spacer members 7, 7,... On the first outer peripheral surface portion 12 is not limited to the arrangement shown in FIG. The wobbling of the first optical member 61 can be prevented by disposing it on the side opposite to the spacer member.

  As described above, since the composite optical element 1 according to this embodiment includes the spacer members 7, 7,..., The composite optical element 1 is molded while controlling the shape of the second optical unit 20 as described later. can do. Therefore, the composite optical element 1 according to the present embodiment exhibits optical characteristics (such as aberration and light collection rate) superior to those of the composite optical element manufactured without controlling the second optical unit.

  2A to 2D are cross-sectional views illustrating a method for molding the composite optical element 1 according to the present embodiment. FIG. 3 is a plan view of the mold 91 as viewed from above in the process shown in FIG. In the molding method of the composite optical element 1 according to the present embodiment, after molding the first optical member 61 to be the first optical unit 10 in the steps shown in FIGS. 2A and 2B, In the step shown in (d), the second optical member 71 to be the second optical unit 20 is joined to the first optical member 61. This is specifically shown below.

  First, as shown in FIG. 2A, a glass preform 60 and a molding apparatus are prepared. The glass preform 60 preferably has a shape very similar to the shape of the first optical unit 10. The molding apparatus has an upper mold 81 and a lower mold 82, and the upper mold 81 and the lower mold 82 have molding surfaces 81a and 82a, respectively. Since the molding surface 81a is a surface for molding the lens surface 14 of the first optical unit 10, it is formed smoothly. On the other hand, since the molding surface 82a is a surface for molding the lens surface 11 of the first optical unit 10, the center of the surface is smooth, while the peripheral edge of the surface is irregular corresponding to the irregular portion 11a. Then, the glass preform 60 is set in a cavity formed by the molding surface 81a and the molding surface 82a.

  Next, the glass preform 60 is heated to near the glass softening temperature, and is pressed as shown in FIG. 2B to form the molding surfaces 81a and 82a of the upper mold 81 and the lower mold 82, respectively. Transfer to the surface. When pressing, the upper mold 81 may be pressed against the surface of the glass preform 60, the lower mold 82 may be pressed against the surface of the glass preform 60, and the upper mold 81 and the lower mold 82 are pressed against the glass preform 60. May be. Then, it is cooled. Thereby, the 1st optical member 61 can be shape | molded. Since the first optical member 61 is molded using the press molding method in this manner, the first optical member 61 is molded by a single molding, unlike when the first optical member is molded using the polishing method or the grinding method. In addition, even if the lens surface is aspherical, it can be molded relatively easily by processing the molding surface.

  Then, the shaping | molding apparatus shown in FIG.2 (c) is prepared. The molding apparatus has a lower mold 91, and a molding surface portion 91 a is formed on the lower mold 91. The molding surface portion 91a is formed for molding the lens surface 22 of the second optical unit 20, and a molding surface outer peripheral portion 91b exists outside the molding surface portion 91a. The spacer members 7, 7,... Are set on the molding surface outer peripheral portion 91b. Specifically, as shown in FIG. 3, the four spacer members 7, 7,... Deploy. Further, the molten resin preform 70 is set on the molding surface portion 91a.

  Then, as shown in FIG. 2D, the first optical member 61 is pressed against the lower mold 91 and pressed. Specifically, first, the lens surface of the first optical member 61 is brought into contact with the surface of the resin preform 70 with the optical axis of the first optical member 61 aligned with the central axis of the molding surface portion 91a. Thus, by arranging the first optical member 61 on the lower mold 91 with the optical axis aligned with the central axis, the second optical member 71 can be joined to the first optical member 61 with the optical axes aligned with each other. it can. Next, the first optical member 61 is pressed against the resin preform 70. As the first optical member 61 is pressed against the resin preform 70, the molten resin flows from the center of the molding surface portion 91a toward the periphery thereof. When the first outer peripheral surface portion of the first optical member 61 comes into contact with the spacer members 7, 7,. Thereby, the composite optical element 1 shown to Fig.1 (a) can be shape | molded.

  As described above, in the molding method of the composite optical element 1 according to the present embodiment, the first outer periphery of the first optical member 61 in the step of bonding the second optical member 71 (the step shown in FIG. 2D). Since the 1st optical member 61 is pressed until a surface part contact | abuts to the spacer members 7, 7, ..., the thickness of the 2nd optical member 71 joined to the 1st optical member 61 is controllable.

  Such a composite optical element 1 can be mounted on an optical apparatus such as an imaging device, an illumination device, and an optical disc recording / reproducing device. The imaging device is a device for photographing a subject, for example, a digital still camera or a digital video camera. The illumination device is a device for irradiating light on an object to be illuminated, and is, for example, a projector. In addition, the optical disc recording / reproducing apparatus records and reproduces digital versatile discs (hereinafter referred to as DVD), compact discs (hereinafter referred to as CD), Blu-ray discs (registered trademark, hereinafter referred to as BD (registered trademark)), and the like. It is a device to do. In general, DVD, CD, and BD have different light source wavelengths and optical disk thicknesses for recording and reproduction, so that a single optical disk recording and reproduction device can record and reproduce DVD, CD, and BD. Although it is necessary to devise an optical system, if the composite optical element 1 according to the present embodiment is used, an optical disc recording / reproducing apparatus compatible with a plurality of types of information recording media can be realized.

  In addition, the shape of the composite optical element body and the shape of the concavo-convex portion are not limited to the above description. In the following first and fifth modified examples, modified examples of these shapes will be shown.

(First modification)
FIG. 4 is a schematic cross-sectional view of the composite optical element 101 according to the first modification of the first embodiment. In the composite optical element 101 according to this modified example, the uneven portion 121 a is formed not only on the lens surface 11 of the first optical unit 10 but also on the lens surface 121 of the second optical unit 120. As a result, the composite optical element 101 according to the present modification can collect three lights having different wavelengths.

(Second modification)
FIG. 5 is a schematic cross-sectional view of a composite optical element 201 according to the second modification of the first embodiment. In the composite optical element 201 according to this modification, the first optical unit 210 has a flat plate shape, and the uneven portion 211a has a stepped cross section and is a diffractive portion.

  Specifically, on the first surface 213 of the first optical unit 210, as in the first optical unit 10 of the first embodiment, the lens surface 211 and the first outer peripheral surface portion 212 exist, and the lens surface 211 is present. The concavo-convex portion 211a is formed on the surface. The second optical unit 220 is bonded to the first optical unit 210 at the bonding surface 222.

(Third Modification)
FIG. 6 is a schematic cross-sectional view of a composite optical element 301 according to the third modification of the first embodiment. The composite optical element 301 according to this modification is substantially the same as the composite optical element 201 according to the second modification, but the concavo-convex part 311a is a lens array part. That is, a plurality of concave lenses are arranged on the lens surface 311.

(Fourth modification)
FIG. 7 is a schematic cross-sectional view of a composite optical element 401 according to the fourth modification of the first embodiment. The composite optical element 401 according to this modification is substantially the same as the composite optical element 1 according to the first embodiment, but the concavo-convex part 411a is a phase step part.

(Fifth modification)
FIG. 8 is a schematic cross-sectional view of a composite optical element 501 according to a fifth modification of the first embodiment. The composite optical element 501 according to this modification is substantially the same as the composite optical element 1 according to the first embodiment, but the concavo-convex part 511a is an antireflection part. That is, a plurality of cone-shaped protrusions are formed on the lens surface, and the cone-shaped protrusions are arranged at a pitch equal to or less than the wavelength of the light to be reflected.

<< Embodiment 2 of the Invention >>
FIG. 9 is a diagram illustrating a configuration of the composite optical element 2 according to the second embodiment. FIG. 9A is a cross-sectional view thereof, and FIG. 9B is a plan view of the composite optical element 2 as viewed from below in FIG. 9A.

  In the composite optical element 2 according to the present embodiment, the second optical unit 30 is bonded to the first optical unit 10 not only at the lens surface 11 but also at the first outer peripheral surface portion 12. That is, in the composite optical element 2, the second optical unit 30 is bonded to the first optical unit 10 on the first surface 13. Such a composite optical element 2 is formed by the resin preform melted during the pressing process flowing out from the molding surface portion of the mold through the molding surface outer peripheral portion or the first outer peripheral surface portion of the first optical member and solidifying. It is formed if the amount of the resin preform is large.

  Further, three spacer members 7, 7,... Of the first embodiment are fixed to the first outer peripheral surface portion 12, and a spacer member (second sphere) having a smaller sphere diameter than the spacer members 7, 7,. Three members 8 are fixed. .. And the spacer members 8, 8,... Are embedded in the second optical unit 30.

  As described above, in the composite optical element 2 according to the present embodiment, since the second optical unit 30 is also joined to the first outer peripheral surface part 12, the composite optical element 2 is attached to the lens barrel by using this part as an attachment part. It can be attached to the optical system. Further, since the spacer members 7, 7,... And the spacer members 8, 8,... Are embedded in the attachment portion, the strength of the attachment portion can be ensured as compared with the case where the spacer member is not embedded. .

<< Embodiment 3 of the Invention >>
FIG. 10 is a schematic cross-sectional view showing the configuration of the composite optical element 3 according to the third embodiment.

  In the composite optical element 3 according to the present embodiment, the second optical unit 30 is bonded to the first optical unit 10 on the first surface 13 as described in the second embodiment, and the spacer members 7, 7, Are exposed from the second outer peripheral surface portion 33 connected to the lens surface 31. As described above, since the spacer members 7, 7,... Are exposed from the second outer peripheral surface portion 33, the mounting area when the composite optical element 3 is attached to the optical system can be reduced. It is possible to prevent heat generated at times from being transmitted to the composite optical element 3.

  11A and 11B are cross-sectional views showing a part of the method for manufacturing the composite optical element 3 according to the present embodiment.

  After the composite optical element 3 according to the present embodiment has formed the first optical member 61 through the steps shown in FIGS. 2A and 2B in the first embodiment, the composite optical element 3 is shown in FIGS. 11A and 11B. The second optical member 72 is joined to the first optical member 61 through the steps shown in the figure. Below, it demonstrates centering on the manufacturing method peculiar to this embodiment.

  After the first optical member 61 is molded according to the method described in the first embodiment, a molding die 94 shown in FIG. 11A is prepared. The molding die 94 is substantially the same as the molding die 91 of the first embodiment, but four concave portions 94c, 94c,... Are formed on the molding surface outer peripheral portion 94b. Each concave portion 94c is formed, for example, as a V-groove in the outer peripheral portion 94b of the molding surface, and is formed on the circumference centered at one point on the optical axis at intervals. Then, a part of the spacer member is inserted into the recesses 94c, 94c,. Since a part of each spacer member 7 is fitted in the mold 94 in this way, a part of each spacer member 7 is exposed from the second outer peripheral surface portion 33 as shown in FIG. 10 in the molded composite optical element 3.

  Thereafter, the molten resin preform 70 is set on the molding surface portion 94 a and the first optical member 61 is pressed against the resin preform 70. Then, as described in the first embodiment, when the first outer peripheral surface portion of the first optical member 61 comes into contact with the spacer members 7, 7,.

  In addition, the shape of the said recessed part is not limited to a V-groove. The recessed part should just be a structure which can insert a part of each spacer member.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the first to third embodiments.

  The second optical unit may be joined to the first optical unit only on the lens surface of the first optical unit as described in the first embodiment, and the first optical unit as described in the second and third embodiments. It may be joined to the entire first surface of the part, or may be joined to the first optical part at the lens surface of the first optical part and its peripheral edge. The second optical part is shaped so as to be bonded at least on the lens surface of the first optical part, although it cannot be generally stated because it differs depending on the amount of resin preform to be supplied and how to apply pressure during pressing. The

  Although the lens surface of the first optical unit is an aspherical surface, it may be a flat surface as described in the second and third modifications of the first embodiment, and includes a spherical surface, a cylindrical surface, a ball striking surface, and It may be a toric surface.

  Although the second optical part is made of resin, specifically, it is an energy curable resin or a thermoplastic resin. The energy curable resin is, for example, a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or the like, and is a resin that is cured by applying predetermined energy (heat, ultraviolet ray, electron beam, or the like). Therefore, when the second optical part is molded using the energy curable resin, the melted resin is set on the molding surface part of the lower mold and then the first optical member is pressed to give a predetermined energy. For example, when the second optical part is molded using an ultraviolet curable resin, it may be cured by irradiating with ultraviolet rays. In addition, when the second optical part is molded using a thermoplastic resin, the molten resin may be set on the uneven part of the lower mold and then cooled by pressing the first optical member. The timing for applying the predetermined energy and the timing for cooling are both when the first outer peripheral surface portion of the first optical member is in contact with the spacer member.

  The materials of the first and second optical parts are not limited to the above materials. Any of the materials may be glass or resin. The first and second optical units may be mixed with impurities that do not affect the optical characteristics.

  The uneven portion may be formed only on the lens surface of the second optical unit, or two or more types may be formed on each of the lens surface of the first optical unit and the lens surface of the second optical unit.

  The shape and the number of spacer members are not particularly limited.

  In addition, the second optical member is molded using the molten resin preform, but the second optical member may be molded using a resin preform that is liquid at room temperature. The second optical member may be molded by setting in a mold and then melting the resin preform by heating or ultraviolet irradiation.

  As described above, the present invention can be mounted on an optical disc recording / playback apparatus, and can also be mounted on an imaging apparatus (digital still camera, digital video camera, etc.) or display apparatus (projector, etc.). .

FIG. 1A is a cross-sectional view of the composite optical element according to Embodiment 1, and FIG. 1B is a plan view of the composite optical element as viewed from below in FIG. 2A to 2D are cross-sectional views illustrating a method for molding a composite optical element according to the first embodiment. FIG. 3 is a plan view when the lower mold is viewed from above in FIG. FIG. 4 is a cross-sectional view of a composite optical element according to Modification 1 of Embodiment 1. FIG. 5 is a cross-sectional view of a composite optical element according to Modification 2 of Embodiment 1. FIG. 6 is a cross-sectional view of a composite optical element according to Modification 3 of Embodiment 1. FIG. 7 is a cross-sectional view of a composite optical element according to Modification 4 of Embodiment 1. FIG. 8 is a cross-sectional view of a composite optical element according to Modification 5 of Embodiment 1. FIG. 9A is a cross-sectional view of the composite optical element according to the second embodiment, and FIG. 9B is a plan view of the composite optical element as viewed from below in FIG. FIG. 10 is a cross-sectional view of a composite optical element according to the third embodiment. FIGS. 11A and 11B are cross-sectional views illustrating a part of the composite optical element molding method according to the third embodiment.

Explanation of symbols

1, 2, 3, 101, 201, 301, 401, 501 Compound optical element 7 Spacer member (first spherical member)
8 Spacer member (second sphere member)
10,210 1st optical part 11 Lens surface (1st optical function surface part)
11a Concave and convex portion 12 First outer peripheral surface portion 13 First surface 15 Composite optical element body 20, 30, 220 Second optical portion 33 Second outer peripheral surface portion 61 First optical member 70 Resin preform (optical material)
71 2nd optical member 91,94 Mold 91a, 94a Molding surface part 91b, 94b Molding surface outer peripheral part 94c Concave part

Claims (10)

A composite optical element having a spacer member fixed to the composite optical element body,
The composite optical element body is:
A first optical part having a first optical functional surface part and a first outer peripheral surface part surrounding the first optical functional surface part and connected to the first optical functional surface part on the first surface;
A second optical part joined to the first optical part in the first optical function surface part,
The composite optical element, wherein the spacer member is fixed to the first outer peripheral surface portion. A composite optical element having a spacer member fixed to the composite optical element body,
The composite optical element body is:
A first optical part having a first optical functional surface part and a first outer peripheral surface part surrounding the first optical functional surface part and connected to the first optical functional surface part on the first surface;
A second optical part joined to the first optical part on the first surface;
The composite optical element, wherein the spacer member is fixed to the first outer peripheral surface portion and is embedded in the second optical portion. A composite optical element having a spacer member fixed to the composite optical element body,
The composite optical element body is:
A first optical part having a first optical functional surface part and a first outer peripheral surface part surrounding the first optical functional surface part and connected to the first optical functional surface part on the first surface;
A second optical part joined to the first optical part on the first surface;
The spacer member is fixed to the first outer peripheral surface portion and is exposed from a second outer peripheral surface portion of the second optical portion opposite to the bonding surface bonded to the first outer peripheral surface portion. A composite optical element characterized by the above. There are three or more spacer members,
One spacer member among the three or more spacer members is disposed on the opposite side of the first optical function surface portion with respect to two spacer members other than the spacer member. The composite optical element according to any one of claims 1 to 3. The spacer members are first spherical members each having substantially the same spherical diameter,
The composite optical element according to claim 4, wherein a second sphere member having a sphere diameter smaller than the sphere diameter of the first sphere member is fixed to the first outer peripheral surface portion. The composite optical element body is a composite lens body,
4. The composite optical element according to claim 1, wherein the first outer peripheral surface portion is a plane substantially perpendicular to an optical axis of the composite optical element body.   4. The composite optical element according to claim 1, wherein the first optical functional surface portion includes an uneven portion. 5.   The said uneven | corrugated | grooved part is at least one of a diffraction part, a lens array part which consists of a some concave or convex lens surface, a phase step part, and a light reflection prevention part, The Claim 7 characterized by the above-mentioned. Composite optical element. A method of manufacturing a composite optical element by bonding a second optical member and a spacer member to a first optical member,
Preparing a first optical member having a first optical functional surface portion and a first outer peripheral surface portion surrounding the first optical functional surface portion and connected to the first optical functional surface portion on a first surface (a) When,
Preparing a molding die having a molding surface portion for molding the second optical member, and a molding surface outer peripheral portion surrounding the molding surface portion and connected to the molding surface portion;
A step (c) of disposing the spacer member on the outer peripheral portion of the molding surface;
A step (d) of setting an optical material to be the material of the second optical member on the molding surface portion and pressing the first optical member against the optical material;
In the step (d),
After the first optical functional surface portion is brought into contact with the optical material and the first optical member is disposed on the mold,
Manufacturing the composite optical element, wherein the first optical member is pressed against the optical material until the first outer peripheral surface portion contacts the spacer member, and the optical material is bonded to at least the first optical functional surface portion. Method. A concave portion is formed in the outer peripheral portion of the molding surface of the molding die prepared in the step (b),
The method for manufacturing a composite optical element according to claim 9, wherein in the step (c), a part of the spacer member is fitted into the recess.

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