JP2008110903A - Method and apparatus for producing optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical device of which the optically effective gross area in comparison with the whole area is large and the light quantity loss is small. <P>SOLUTION: The production apparatus 10 of the optical device includes a pair of an upper die 12 and a lower die 14 separately placed up and down and facing to each other, an upper heat transfer plate 16 and a lower heat transfer plate 18 for heating the upper die 12 and the lower die 14, and an air cylinder 20 for moving the upper die 12 toward the lower die 14. The lower die 14 and the upper die 12 have a plurality of continuously formed concave molding faces 14a and 12a, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing an optical element having a plurality of optical surfaces formed by fusing and bonding a plurality of optical element materials.

  Conventionally, a molding means using a molding die is known as one of methods for mass-producing high-performance optical elements having a plurality of convex optical surfaces with a single lens, such as an AF lens for a camera. ing.

  For example, Patent Document 1 discloses a technique for forming a lens assembly by collecting a plurality of such lenses. That is, as shown in FIG. 14, the lens assembly 100 is formed by assembling a plurality of lenses 111 having a flange portion 111b formed around the optical function portion 111a, and the adjacent lens 111 has a flange portion 111b. A groove 112 that is in direct contact and has a depth in the optical axis O direction of the optical function portion 111 a is formed over the entire length of each contact portion 113.

If this lens assembly 100 is cut and separated along the groove 112 after molding, a plurality of lenses can be obtained simultaneously.
JP 2002-265226 A

  However, in Patent Document 1, although one optical element is not configured to have a plurality of optical surfaces, the boundary of each optical function part 111a forms a flange part 111b such as a flat part, and the lens. The optical effective total area with respect to the entire area of the aggregate 100 is reduced. For this reason, when the lens assembly 100 is assumed to be one optical element, the amount of light is greatly reduced. Moreover, in patent document 1, since the flange part 111b of the boundary of each optical function part 111a is wide, size reduction as one optical element was difficult.

  The present invention has been made to solve such a problem, and an object thereof is to provide a method and an apparatus for manufacturing an optical element that has a large optical effective total area with respect to the entire area and has little light loss.

In order to achieve the object, the invention according to claim 1
In a method for manufacturing an optical element in which an optical element material is pressure-molded using a pair of opposing molds,
Forming a plurality of continuous concave molding surfaces on at least one of the pair of molding dies, and supplying the optical element material one by one for each molding surface;
And heating and pressurizing the supplied optical element material to fuse and bond the adjacent optical element materials to each other to form a plurality of continuous optical surfaces.

The invention according to claim 2 is the method of manufacturing an optical element according to claim 1,
The optical element materials supplied one by one are made of the same material.
The invention according to claim 3 is the method of manufacturing an optical element according to claim 1,
The optical element materials supplied one by one are made of different materials.

The invention according to claim 4 is the method for manufacturing an optical element according to any one of claims 1 to 3,
The optical element material supplied one by one has a spherical shape or a cylindrical shape.

The invention according to claim 5 is the method for manufacturing an optical element according to any one of claims 1 to 4,
The total volume of the optical element materials supplied one by one is managed so as to be a value substantially equal to the volume of the product.

The invention according to claim 6
In an optical element manufacturing apparatus that press-molds a heat-softened optical element material using a pair of opposing molds,
A plurality of continuous concave molding surfaces are formed on at least one of the pair of molding dies,
One optical element material can be supplied for each molding surface.

The invention according to claim 7 is the optical element manufacturing apparatus according to claim 6,
The molding surface includes the concave molding surface formed on one of the pair of molding dies, and a plurality of continuous concave or convex molding surfaces formed on the other of the pair of molding dies. It is characterized by that.

The invention according to claim 8 is the optical element manufacturing apparatus according to claim 6,
The molding surface includes the concave molding surface formed on one of the pair of molding dies and one concave, convex, or planar molding surface formed on the other of the pair of molding dies. Any one of these is included.

The invention according to claim 9 is the optical element manufacturing apparatus according to any one of claims 6 to 8,
The pair of molding dies are divided and formed for each of the molding surfaces.

  According to the present invention, a plurality of continuous concave molding surfaces are formed on at least one of the molding dies, one optical element material is supplied for each molding surface, and a plurality of continuous molding surfaces are fusion bonded. Thus, an optical element having a large optical effective total area and a small amount of light loss can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Description of optical element manufacturing apparatus)
FIG. 1 is a sectional front view of an optical element manufacturing apparatus according to the present embodiment. In the figure, this manufacturing apparatus 10 includes an upper mold 12 and a lower mold 14 as a pair of opposed molds, and an upper heat transfer plate 16 and a lower transfer as heating means for heating the upper mold 12 and the lower mold 14. An air cylinder 20 is provided as a pressurizing means for relatively moving the hot plate 18, the upper mold 12 and the lower mold 14 in the opposing direction.

  The upper mold 12 and the lower mold 14 are inserted into the sleeve 15 from both ends of the sleeve 15 so that the molding surfaces 12a and 12a of the upper mold 12 and the molding surfaces 14a and 14a of the lower mold 14 face each other. Yes. In the present embodiment, the molding surfaces 12a and 12a of the upper mold 12 are formed such that the adjacent sides are continuously concave. Similarly, the molding surfaces 14a and 14a of the lower mold 14 are also formed as concave surfaces on the adjacent sides.

  Here, “continuously” means a state in which arc portions such as adjacent molding surfaces 14a are in contact with each other or are partially overlapped. The upper mold 12 is slidable in the axial direction of the sleeve 15. One spherical preform 22 as an optical element material is disposed between the molding surface 12a of the upper mold 12 and the molding surface 14a of the lower mold 14 one by one.

  Heaters 24 and 26 are embedded in the upper heat transfer plate 16 and the lower heat transfer plate 18, respectively. Then, by operating the air cylinder 20, the upper mold 12 is moved up and down via the upper heat transfer plate 16 to pressurize the preform 22 and perform a molding operation.

The heaters 24 and 26 and the air cylinder 20 are controlled in timing such as temperature setting and pressurization according to instructions from a control device (not shown).
The upper mold 12 and the lower mold 14 are manufactured by polishing a cemented carbide such as tungsten carbide (WC). The preform 22 uses, for example, a spherical (ball-shaped) commercially available optical glass (for example, S-BAL42, L-TIM28, etc. manufactured by OHARA INC.).

  Thus, when two or more kinds of preforms 22 are used, the ones having close glass transition points are selected so that they can be molded at substantially the same heating temperature. The preform 22 may have a gob shape other than a ball shape or a cylindrical shape, for example.

  Furthermore, in the present embodiment, description will be made using optical glass as the material of the preform 22 which is an optical element material. However, other than optical glass, for example, synthetic resin or other plastic materials may be used.

  According to the present embodiment, since a plurality of continuous concave molding surfaces 12a, 14a are formed on the upper mold 12 and the lower mold 14, one preform 22 is supplied for each molding surface, and heating / heating is performed. When pressed, an optical element (such as 28) having a plurality of continuous optical surfaces (such as 28a) can be obtained as described later.

FIG. 2 is a sectional front view of an optical element manufacturing apparatus according to another embodiment. In addition, the same code | symbol is attached | subjected to the same or equivalent member as FIG. 1, and the description is abbreviate | omitted.
In this embodiment, in the optical element manufacturing apparatus 10, the upper mold 12 and the lower mold 14 are divided into two upper molds 12-1 and 12-2 and lower molds 14-1 and 14-2 that face each other. ing. As described above, the upper mold 12 and the lower mold 14 are formed separately for each concave molding surface 12a, 12a (14a, 14a).

According to this embodiment, since a shaping | molding die can be manufactured for every divided concave molding surface 12a, 14a, die manufacture becomes easy. In addition, when any one of the plurality of concave molding surfaces 12a and 14a is deteriorated, it is sufficient to replace only that portion, so that maintenance is facilitated.
(Description of optical element manufacturing method)
FIG. 3 is an enlarged view of a main part of the optical element manufacturing apparatus 10 shown in FIG.

  At the time of molding, for example, one preform 22 is supplied for each of two concave molding surfaces 14a, 14a formed continuously on the lower mold 14. Next, the air cylinder 20 is operated to lower the upper mold 12 and the preform 22 is heated and pressurized to be molded into a desired shape. In the optical element 28 as a product thus obtained, two adjacent preforms 22 and 22 are fusion-bonded to each other to form continuous optical surfaces 28a and 28a (see FIG. 8 and the like).

  In the present embodiment, a ball-shaped material is used as the preform 22 for each of the molding surfaces 14a and 14a. If the preform 22 is ball-shaped, the molding surfaces 12a and 14a of the upper mold 12 and the lower mold 14 are concave surfaces, so that the two preforms 22 are fusion-bonded to each other. As a result, the molded optical element has a large optical effective total area with respect to the entire area, and light loss is reduced.

  In this embodiment, the volume of the preform 22 is controlled so as to be a value substantially equal to the volume of the optical element after molding. The ball-shaped preform 22 can be easily volume-controlled, and if the volume-controlled ball-shaped preform 22 is used, post-processing of the molded optical element becomes unnecessary.

  3 shows an example in which the molding surfaces 12a and 14a of the upper mold 12 and the lower mold 14 are both concave surfaces. However, the present invention is not limited to this. For example, the molding surface 12a of the upper mold 12 may be a convex surface. good. In addition, although the number of molding surfaces 12a and 14a of the upper mold 12 and the lower mold 14 is two as an example in FIG. 3, two or more molding surfaces may be formed continuously.

  4A is a side view of the optical element 28 obtained by using the mold shown in FIG. 3, and FIG. 4B is a plan view thereof. The optical element 28 has two optical surfaces 28a and 28a, which are fusion-bonded at the boundary surface.

  When the optical element 28 is molded, a ball-shaped preform 22 that has been entirely polished is supplied to each of the molding surfaces 14 a and 14 a of the lower mold 14. Next, the heaters 24 and 26 in FIG. 1 are energized to heat the preform 22 to a temperature at which it can be molded. Further, the air cylinder 20 is operated to move the upper mold 12 closer to the lower mold 14 and deform the preform 22.

  Thus, the pressurized preform 22 is fusion-bonded to each other in the vicinity of the boundary between the optical surfaces 28a and 28a. Then, the preform 22 formed after cooling is taken out from the upper and lower molds 12 and 14, and one optical element 28 is obtained.

  In this case, the optical element 28 having a plurality of optical surfaces 28a can use the preform 22 made of the same material, or can use the preforms 22 made of two or more different materials. Further, by using the preform 22 made of a different material, the degree of freedom in design can be expanded, for example, the refractive index and the focal length can be changed. However, when using a preform 22 made of a different material, it is preferable to use a preform having a glass transition point close to that it can be molded at substantially the same heating temperature.

  In addition, as shown in FIG. 5, although shape | molding using one disk-shaped or plate-shaped preform 22 'is also considered, in this case, molding surface 12a, 14a of the upper mold | type 12 and the lower mold | type 14 is considered. There is a risk that air may be trapped between and the preform 22 '. On the other hand, if the ball-shaped preform 22 supplied for each molding surface 14a is used as in this embodiment, air easily escapes to the outside, so that surface accuracy is poor due to air trapping on the optical surface of the optical element. Can be suppressed.

  As shown in FIG. 6, the molding surfaces of the upper mold 12 and the lower mold 14 are formed with two concave molding surfaces 14 a and 14 a on the lower mold 14, and the upper mold 12 has one molding surface. A concave molding surface 12a-1 may be formed.

  Further, as shown in FIG. 7, two concave molding surfaces 14 a can be formed on the lower mold 14, and one convex molding surface 12 a-2 can be formed on the upper mold 12. Further, as shown in FIG. 8, two concave molding surfaces 14 a and 14 a may be formed on the lower mold 14, and a planar molding surface 12 a-3 may be formed on the upper mold 12.

Fig.9 (a) is a front view of the optical element 128 obtained using the other shaping | molding die, FIG.9 (b) is the top view.
Unlike the optical element 28 shown in FIGS. 4 (a) and 4 (b), the optical element 128 is fusion-bonded so as to overlap to some extent at the boundary between the optical surfaces 128a and 128a. Thereby, the optical effective total area of the optical element 128 becomes large, and since each optical surface 128a overlaps, size reduction can be achieved. In order to mold the optical element 128 in which the optical surfaces 128a overlap in this way, the protruding amounts of the boundary portions A and B between the molding surfaces 12a and 14a of the upper mold 12 and the lower mold 14 shown in FIG. This is achieved by lowering slightly.

  Fig.10 (a) is a front view of the optical element 228 obtained using the shaping | molding die (FIG. 11) mentioned later, FIG.10 (b) is the top view. The optical element 228 has four optical surfaces 228a and is fusion-bonded so as to overlap each other to some extent at the boundary between the optical surfaces 228a.

FIG. 11 (a) is a sectional front view of the mold, and FIG. 11 (b) is a plan view thereof.
At the time of molding by this molding die, ball-shaped preforms 22 that are entirely polished are supplied for each of the four molding surfaces 14 a of the lower die 14. As shown in FIGS. 10A and 10B, the optical element 228 formed in this way is fused and joined at the boundaries of the four optical surfaces 228a.

  FIG. 12A is a front view of an optical element 328 obtained using another mold, and FIG. 12B is a plan view thereof. The optical element 328 is a lens array having 19 optical surfaces 328a, and these optical surfaces 328a are fusion-bonded to each other at the boundary.

  In molding, a molding die as shown in FIG. 8 having a large number of concave molding surfaces 14a is used. Then, the preforms 22 are supplied one by one to the concave molding surface 14 a formed on the lower mold 14. Then, the preform 22 is pressed by a planar molding surface 12 a-3 formed on the upper mold 12.

FIG. 13 is a plan view of an optical element 428 obtained using still another mold.
This optical element 428 is a lens array having 37 optical surfaces 428a, and these optical surfaces 428a are fusion-bonded so as to overlap to some extent at the boundary. Each of these optical surfaces 428a is a regular hexagon. As a result, the optical effective total area of the optical element 428 further increases with respect to the total area of the optical element.

  According to the present embodiment described above, since a plurality of optical surfaces (28a, etc.) are continuously formed on each optical element (28, etc.) to be molded, the total optical effective area of each optical element is increased. , The amount of light increases significantly. Further, on each molding surface (14a, etc.) of the molding die, one piece whose volume is controlled so that the total volume of the preform 22 is substantially equal to the volume of the optical element (28, etc.) to be molded. By supplying each one, post-processing of each optical element (28 etc.) formed can be omitted.

  Further, by supplying one preform 22 to each molding surface (14a, etc.) of the molding die, no air accumulation or the like occurs on the optical surface (28a, etc.) of each optical element (28a, etc.). The surface accuracy of the element (28 etc.) is improved.

It is a rough section front view of the manufacturing device of the optical element in this embodiment. It is a general | schematic front view of the manufacturing apparatus of the optical element in other embodiment. It is a sectional front view of a shaping | molding die. (A) is a front view of an optical element, (b) is the top view. It is a cutaway front view of a shaping | molding die at the time of using a disk-shaped preform. FIG. 2 is a cross-sectional front view of a molding die in which two concave molding surfaces are formed on the lower die and one concave molding surface is formed on the upper die. FIG. 2 is a cross-sectional front view of a molding die in which two concave molding surfaces are formed on the lower die and one convex molding surface is formed on the upper die. FIG. 2 is a cross-sectional front view of a molding die in which two concave molding surfaces are formed on the lower die and a planar molding surface is formed on the upper die. (A) is a front view of an optical element, (b) is the top view. (A) is a front view of an optical element, (b) is the top view. (A) is a sectional front view of a mold, and (b) is a plan view thereof. (A) is a front view of an optical element, (b) is the top view. It is a top view of an optical element. It is a figure which shows the prior art example of a lens assembly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical element manufacturing apparatus 12 Upper mold 12a Molding surface 14 Lower mold 14a Molding surface 15 Sleeve 16 Upper heat transfer plate 18 Lower heat transfer plate 20 Air cylinder 22 Preform 24 Heater 26 Heater 28 Optical element 28a Optical surface 128 Optical element 128a Optical surface 228 Optical element 228a Optical surface 328 Optical element 328a Optical surface 428 Optical element 428a Optical surface

Claims (9)

In a method for manufacturing an optical element in which an optical element material is pressure-molded using a pair of opposing molds,
Forming a plurality of continuous concave molding surfaces on at least one of the pair of molding dies, and supplying the optical element material one by one for each molding surface;
A step of heating and pressurizing the supplied optical element material, and fusing and bonding the adjacent optical element materials to each other to form a plurality of continuous optical surfaces. Device manufacturing method. The method of manufacturing an optical element according to claim 1, wherein the optical element materials supplied one by one are made of the same material. The method of manufacturing an optical element according to claim 1, wherein the optical element materials supplied one by one are made of different materials. The method of manufacturing an optical element according to any one of claims 1 to 3, wherein the optical element materials supplied one by one have a spherical shape or a cylindrical shape. 5. The optical element according to claim 1, wherein the total volume of the optical element materials to be supplied one by one is managed to be substantially equal to the volume of the product. Production method. In an optical element manufacturing apparatus that press-molds a heat-softened optical element material using a pair of opposing molds,
A plurality of continuous concave molding surfaces are formed on at least one of the pair of molding dies,
An optical element manufacturing apparatus characterized in that one optical element material can be supplied for each molding surface. The molding surface includes the concave molding surface formed on one of the pair of molding dies, and a plurality of continuous concave or convex molding surfaces formed on the other of the pair of molding dies. The apparatus for manufacturing an optical element according to claim 6. The molding surface includes the concave molding surface formed on one of the pair of molding dies and one concave, convex, or planar molding surface formed on the other of the pair of molding dies. Any one of these is included. The optical element manufacturing apparatus of Claim 6 characterized by the above-mentioned. The optical element manufacturing apparatus according to any one of claims 6 to 8, wherein the pair of molding dies are divided for each of the molding surfaces.