JP5269477B2 - Optical element manufacturing method, optical element manufacturing apparatus, and optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical device having a thinner edge part around an optical functional face by hot-pressing a molding material by dividing it into the optical functional face and the other part. <P>SOLUTION: The manufacturing apparatus 10 of an optical device is provided with a molding material 41 having a first optical material 41<SB>1</SB>arranged at the die center between a pair of opposing upper die 42 and lower die 43 and a second optical material 41<SB>2</SB>arranged in a direction crossing the axis of the die center, an outer diameter-restricting ring 45 arranged on an outer circumference side of the second optical material 41<SB>2</SB>, and an air cylinder 36 for press-molding the heated and softened molding material 41, and thereby the optical functional face is molded from the first optical material 41<SB>1</SB>and the circumference of the optical functional face is integrally molded from the second optical material 41<SB>2</SB>. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to an optical element manufacturing method , an optical element manufacturing apparatus , and an optical element that obtain an optical element by heat-softening a molding material disposed between a pair of opposed upper and lower molds.

  An optical element such as a lens is attached to an optical device by using, for example, an outer peripheral portion (edge portion) thereof. However, as the optical device is reduced in size and weight, a thinner outer peripheral portion (edge portion) is required. Conventionally, as a method for thinning the outer peripheral portion of the optical element, for example, a technique has been proposed in which the outer peripheral portion is made of a metal frame and the metallic frame is insert-molded into a molding material such as glass.

That is, for example, Patent Document 1 discloses a technique of an optical component in which a thin metal plate is integrally attached outside the effective diameter of the optical element. The optical component includes a molding material and a metal plate disposed around the molding material. When the molding material is heated and pressed to mold the optical element, the optical element and the metal plate are integrally and closely bonded. ing.
JP 2007-133197 A

  However, in Patent Document 1, residual stress may occur on the optically effective diameter surface of the optical element due to a difference in linear expansion coefficient between the molding material and the metal plate. For this reason, the shape accuracy of the effective diameter surface of the optical element is deteriorated. In order to solve this, it is necessary to increase the processing accuracy of the metal plate, for example, but this increases the manufacturing cost.

The present invention has been made in order to solve such a problem. An optical element having a thin outer peripheral portion (edge portion) of the optical functional surface is obtained by dividing the molding material into an optical functional surface and other portions and performing heat pressing. An object of the present invention is to provide an optical element manufacturing method , an optical element manufacturing apparatus , and an optical element .

The invention according to 請 Motomeko 1,
In the method of manufacturing an optical element, a molding material is disposed between a pair of upper and lower molds facing each other, the molding material is heated and softened, and press molding is performed to obtain an optical element.
The molding material has a first member and at least three second members,
The first member and the at least three second members are glasses, and the compositions of the glasses are different.
Placing the first member in the center of the mold;
The at least three second members are divided and arranged in a direction intersecting the mold center axis,
By pressing the first member and the at least three second members, an optical function surface is formed by the first member, and the optical function surface is integrally formed by the at least three second members. It shape | molds and it joins in an independent state with respect to the said 1st member, dividing the said at least 3 2nd member .

The invention according to claim 2 is the method of manufacturing an optical element according to claim 1 ,
The at least three second members have a coefficient of linear expansion smaller than that of the first member.
The invention according to claim 3 is the method of manufacturing an optical element according to claim 1 or 2 ,
The at least three second members are supplied into the mold after molding the first member, and after molding the first member, the at least three second members are molded while pressing and holding the upper mold. It is characterized by doing.

The invention according to 請 Motomeko 4,
In the optical element manufacturing apparatus,
The first member arranged at the mold center between a pair of the upper mold and the lower mold facing each other, and the first member and the glass are different from each other in the composition of the glass, and divided in the direction intersecting the mold center axis a molding material having at least three second members arranged,
An outer diameter regulating member disposed on an outer peripheral side of the at least three second members;
Press means for press-molding the heat-softened molding material,
Wherein in a state where the first member by molding the optical function surface in the integrally molded around the optical functional surface on at least three of the second member, independent while the divided at least three of the second member It joins with respect to 1st part, It is characterized by the above-mentioned.
The invention according to claim 5
In the optical element,
A central optical functional unit having an optical functional surface;
And at least three edge portions formed around the optical function portion,
The optical function portion and the at least three edge portions are glasses, and the compositions of the glasses are different.
The at least three edge portions are divided and joined to the optical function surface portion in an independent state.

  According to the present invention, an optical element having a thin outer peripheral portion (edge portion) of the optical functional surface can be obtained by dividing the molding material into an optical functional surface and other portions and heating and pressing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a cross-sectional view showing an outline of an optical element manufacturing apparatus according to the present embodiment, and FIG. 2 is a plan view taken along the line II-II.

  The optical element manufacturing apparatus 10 includes a molding chamber 13 that is partitioned on a device base 11 by a predetermined size. The mold block 40 is carried into the molding chamber 13, the molding material 41 accommodated in the mold block 40 is press-molded, and the optical element 48 (see FIG. 4C) is molded.

A heating / press stage 21 is provided in the molding chamber 13. The mold block 40 is heated by the heating / press stage 21 and the molding material 41 is press-molded.
In the present embodiment, the case where the heating / press stage 21 is provided in the molding chamber 13 and the molding material 41 is heated / pressed here will be described. However, the present invention is not limited to this.

  For example, a plurality of stages such as a heating stage, a press stage, and a cooling stage may be provided in the molding chamber 13, and the molding material 41 may be molded by sequentially conveying the mold block 40 to each of these stages.

  On the entrance side of the molding chamber 13, an entrance shutter 16 for carrying the mold block 40 is provided. Further, an exit shutter 18 for carrying out the molded die block 40 is provided on the exit side of the molding chamber 13.

  A pusher (not shown) is provided outside the entrance shutter 16, and the mold block 40 is pressed with a predetermined pressure by the pusher and is carried into the molding chamber 13 from the entrance shutter 16.

  The inside of the molding chamber 13 is replaced with an inert gas (for example, nitrogen gas) by an inert gas supply device (not shown). By this inert gas replacement, in this embodiment, the oxygen concentration in the molding chamber 13 is set to 30 ppm or less. Thereby, the oxidation of the members constituting the mold block 40 is mainly prevented.

Then, heating and pressing stage 21 is provided with a heating plate 33 ₁ and the lower heating plate 33 ₂ on opposite vertically. The distal end side of the upper heating plate 33 ₁ and the lower heating plate _332, the upper molding plate 34 ₁ and the lower molding plate 34 ₂ is fixed.

The upper heating plate 33 ₁ and the lower heating plate _332, respectively upper cartridge heaters 35 ₁ and the lower cartridge heaters 35 ₂ is incorporated. The air cylinder 36 serving as pressing means for driving the upper heating plate ₃₃₁ in the vertical face direction is provided.

As the upper heating plate 33 ₁ (and the upper molding plate 34 ₁ ) is moved up and down by the air cylinder 36, operations such as clamping and pressing of the die block 40 are performed. By pressing the mold block 40, the molding material 41 accommodated therein is molded into an optical element 48 having a desired shape.

As shown in FIG. 2, the molding material 41 is closed and the first optical material 41 ₁ spherical as a first member, an annular second optical material 41 (ring-shaped) ₂ as the second member doing. As described later, the first optical material 41 ₁ is the mold center, that is, placed in the center of the molding surface 43a of the lower die 43. Furthermore, the placing direction, i.e. a flat molding surface 43b of the outer peripheral side of the molding surface 43a of the lower mold 43 in which the second optical material 41 ₂ intersecting with the mold center. An outer diameter regulating ring 45 is disposed so as to regulate the outer peripheral side of the second optical material 412.

Next, the configuration of the mold block 40 will be described with reference to FIG.
The mold block 40 includes an upper mold 42, a lower mold 43, an outer diameter regulating ring 45, and a sleeve 44. The upper mold 42 and the lower mold 43 are inserted from both ends of the sleeve 44 so that the molding surfaces 42 a and 43 a (and 43 b) face each other inside the sleeve 44. The molding surface 42a of the upper mold 42 is formed in a shallow concave spherical shape.

  The molding surface 43a of the lower mold 43 is formed in a deep concave spherical shape. A flat molding surface 43b is formed on the outer peripheral side of the molding surface 43a. The outer diameter regulating ring 45 is formed in an annular shape (ring shape). The outer diameter regulating ring 45 is placed on the flat molding surface 43 b on the outer circumferential side of the lower mold 43 in a state of being fitted to the inner circumference of the sleeve 44.

The shapes of the molding surfaces 42a and 43a are not limited to spherical surfaces, and may be aspherical surfaces, for example. Further, the radius of curvature may be the same or different.
The upper mold 42 is slidable in the axial direction of the sleeve 44. Between the molding surface 43a of the molding surface 42a and the lower die 43 of the upper die 42 (and 43 b), the first optical material 41 ₁ and the second optical material 41 ₂ is disposed.

In the present embodiment uses a spherical glass of φ6mm as the first optical material 41 _1. The second optical material 41 ₂ as an inner diameter Fai11mm, outer diameter Fai14.97Mm, and a glass of annular thickness 0.32 mm (ring). The first optical material 41 ₁ and the second optical material 41 ₂ using the same material for the glass transition point 540 ° C. of La system (lanthanide).

Further, on the upper and lower ridge portions of the second optical material 41 _{and second} outer peripheral side, as shown in FIG. 4A described below, chamfered ₄₁ 2 a of C0.5Mm, 41 ₂ b is applied. A space is formed between the outer peripheral side of the _second optical material 412 and the inner peripheral side of the outer diameter regulating ring 45 by the chamfering 41 ₂ a and 41 ₂ b. Then, this space serves to absorb the first optical material 41 ₁ and the variation of the second volume plus optical material 41 _2.

As a result, it is possible to prevent adverse effects such as the occurrence of burrs by the softened glass portion entering the mold gap.
The upper mold 42, the lower mold 43, the outer diameter regulating ring 45, and the sleeve 44 are finished by polishing a cemented carbide such as tungsten carbide (WC).

Next, a process of forming the optical element 48 will be described based on FIGS. 4A to 4C.
Figure 4A is a view showing a state in which sandwiched between the upper mold 42 and the lower mold 43 the first optical material 41 _1, Figure 4B shows a state where the press-formed part way, FIG. 4C finally optically It is a figure which shows the state by which the element 48 was shape | molded.

When the mold block 40 is assembled, the sleeve 44 is inserted into the lower mold 43 and the outer diameter regulating ring 45 is inserted inside the sleeve 44.
Then, a direction intersecting the second optical material 41 ₂ relative to the mold center axis, i.e., arranged on the outside of the forming surface 43b than the center of the molding surface 43a of the lower die 43. At this time, the second optical material 41 ₂ is arranged inside the forming surface 43b on a and the outer size specification system ring 45. Furthermore, arranging the first optical element 41 ₁ on the forming surface 43a of the center of the lower mold 43.

Next, the upper mold 42 is inserted into the inner surface of the sleeve 44.
Thus, as shown in FIG. 4A, the first optical material 41 ₁ is in a state of being sandwiched between the molding surface 43a of the molding surface 42a and the lower die 43 of the upper die 42.

The mold block 40 assembled in this way is put into the molding chamber 13 (see FIG. 1).
In the molding chamber 13, the mold block 40 is heated to a molding temperature of 600 ° C. At this time, the mold block 40 is heated by energizing the upper and lower cartridge heaters 35 ₁ and 35 ₂ .

After heating, a first press-forming of the optical material 41 ₁ in the pressing pressure 50kgf by operating the air cylinder 36.
At this time, as shown in FIG. 4B, the first press of the optical material 41 ₁ (collapse amount) is about 3.5mm in the mold center axis direction.

After the first optical material 41 ₁ of the press ends, further actuates the air cylinder 36, the first optical material 41 ₁ and the second optical material 41 ₂ to press molding press pressure as 100 kgf. In step, the first optical material 41 ₁ and the second optical material 41 ₂ are joined by fusion at the interface.

At this time, the press amount of the second optical material 41 ₂ (collapse amount) is 0.02mm to mold the central axis direction. The second optical material 41 _2, because it is restricted to the outer peripheral side outside size specification system ring 45, the second optical material 41 ₂ softened is displaced to the mold center side, a first optical material 4 _{1 1} is fused and joined. Moreover, in the present embodiment, the first optical material 41 ₁ and the second optical material 41 ₂ uses a glass of the same material. For this reason, since the linear expansion coefficients of the first and second optical materials 41 ₁ and 41 ₂ are the same, the stress generated on the lens effective diameter surface is small. For this reason, the residual stress is very small.

In the present embodiment, the molding material 41 and the split first optical material 41 ₁ and the second optical material 41 _2, and molding an optical function surface in the first optical material 41 _1, the second optical material 41 ₂ In this way, the area around the optical function surface is integrally formed. Thus, by selecting the second optical material 41 _{and second} section to a desired value, it is possible to form a thin thickness of the outer peripheral portion of the optical function surface of the optical element 48 (edge portion).

Further, it is possible to reduce the fusion strength between the mold by setting a small second volume of the optical material 41 _2. Thereby, it is possible to prevent the molded optical element 48 from being chipped or cracked.

As described above, the volume obtained by adding the first optical material 41 ₁ and the second optical material 41 _2, the difference between the volume of the optical element 48 to be molded (volume variation), the second optical material 41 ₂ of the chamfered portion ₄₁ is absorbed by 2 a, 41 ₂ b.

Also, if not provided the chamfered portion ₄₁ 2 a, 41 ₂ b, the first optical material 41 ₁ and the second optical material 41 ₂ volume variation, the outer size specification system ring 45 and upper die 42 and lower die There is a possibility that the glass flows into the gap with 43 and becomes a burr.

  As shown in FIG. 4C, after the press is completed, the mold block 40 is cooled to room temperature. In this way, the distortion and shape stabilization of the molded product are achieved. After sufficiently cooling, the molded optical element 48 (lens) is taken out. The outer diameter regulating ring 45 is separated from the optical element 48.

As shown in FIG. 4C, the shape of the molded optical element 48 is a biconvex shape with a center thickness T = 2.5 mm, an edge thickness (outer peripheral thickness) t = 0.3 mm, and an outer diameter D = φ15 mm. there were. In this optical element 48, a fusing mark (interface mark) 50 was observed. The fusion remain 50 is a thin portion that looks like a shadow at the junction of the first optical material 41 ₁ and the second optical material 41 _2. The diameter of this fusion mark 50 was about φ11 mm.

However, since the fusion mark 50 exists outside the effective diameter S (optical function surface diameter S) of the optical element 48, there is no problem in optical function. That is, in this embodiment, is an optical function surface is formed in the first optical material 41 _1, further extends the first optical material 41 ₁ to the outside beyond the optical-function surface.

The optical element 48 thus molded satisfied the design specifications in terms of the shape accuracy of the optical function surface. The time required for pressing in this embodiment was about 90 seconds.
On the other hand, when the molded optical element 48 is molded with one spherical molding material 41, the required molding material 41 has a diameter of φ6.4 mm. When this molding material 41 of φ6.4 mm is used, the time required for pressing is about 180 seconds. Therefore, the time required for this press is about 90 seconds, and the press can be performed in about ½ time.

According to the present embodiment, the molding material 41 is divided into a portion corresponding to the optical function surface of the optical element 48 (first optical material 41 ₁ ) and another portion (second optical material 41 ₂ ), Since these are softened by heating and press molding is performed, an optical element 48 having a thin outer peripheral portion (edge portion) can be obtained while ensuring the accuracy of the optical functional surface. Accordingly, since the molding material 41 is divided and molded, the tact time can be shortened.

The first optical material 41 ₁ and the second optical material 41 ₂ because of the use of glass of the same material, the residual stress generated in the lens effective diameter S surface of the optical element 48 to be molded is small. For this reason, the shape accuracy of the optical element 48 can be maintained high.

Further, according to this embodiment, since the first optical material 41 ₁ and the second optical material 41 ₂ is molded independently, it is possible to perform high-precision molded in a short time, these first And the second optical material 41 ₁ , 41 ₂ and the mold can be reduced in fusion force. Therefore, it is possible to obtain a high-quality optical element 48 with good mold separation and no residual stress or cracking.
[Second Embodiment]
5 and 6 are cross-sectional views of a mold block 40 used in the optical element manufacturing method according to the second embodiment.

In addition, the same code | symbol is attached | subjected and demonstrated to the member the same as that of 1st Embodiment, or equivalent.
The configuration of the mold block 40 is substantially the same as that of the first embodiment. However, in the present embodiment, a spherical glass φ1.2mm as the second optical material 41 _2, which was placed in a mold center, further intersects the second optical material 41 ₂ with respect to the mold center axis direction, in the present embodiment that was arranged evenly three on the outer peripheral portion of the first optical material 41 ₁ are different.

As the second optical material 41 _2, using boric-silicate based glass, the transition point 550 ° C., the linear expansion coefficient is 76 × ^{10 -7} / ℃.
Further, as the first optical material 41 _1, using spherical glass 6mm. The optical material 41 ₁ in the first, the coefficient of linear expansion at the transition point of 541 ° C. is 92 × ^{10 -7} / ℃ of La based glass (lanthanum-based glass).

That is, in this embodiment, the first optical material 41 ₁ and the second optical material 41 ₂ is a glass together, have different compositions of these glasses to each other. The second optical material 41 ₂ first linear expansion coefficient than the optical material 41 ₁ is small.

The lower mold 43 has three concave surfaces 43c having a depth of 0.2 mm. The second optical material 41 ₂ is disposed at the center of the concave surface 43c. In the present embodiment, the divided frame 52 is assembled to the lower mold 43.

In the above configuration, by pressing by the air cylinder 36 (see FIG. 1), three second optical material 41 ₂ spreads in a substantially circular shape. Thus, three of the second optical material 41 ₂ is fused bonded first optical material 41 ₁ with an independent state three.

Again, the optical functional surface formed in the first optical material 41 _1, around the optical functional surface is formed integrally with three second optical material 41 _2.
In the present embodiment, the case where three _second optical materials 412 are used has been described, but the number is not limited to this. For example, the number may be four or more.

According to this embodiment, as the second optical material 41 _2, it can be manufactured at low cost since it is possible to use a spherical ball preform. Although not shown, an irregularly shaped optical element in which three outer peripheral portions (edge portions) are formed around the central optical function portion can be obtained as a molded optical element.

Further, since the area is formed by the second optical material 41 ₂ is smaller than the material forming the annular used in the first embodiment (a ring), the stress applied to the lens is reduced. Therefore, an optical element having a small residual stress can be obtained.

Furthermore, since the spherical optical materials 41 ₁ and 41 ₂ have high processing accuracy and little volume variation, it is not necessary to provide the chamfered portions 41 ₂ a and 41 ₂ b as in the first embodiment. Further, it has advantages such as better shape accuracy than the case of an annular shape (ring shape).

In the present embodiment, the first optical material 41 ₁ and the second optical material 41 ₂ is a glass together is different from the composition of these glasses. Further, the second optical material 41 ₂ using those linear expansion coefficient than the first optical material 41 ₁ is small.

  For this reason, for example, there are materials that have high adhesion to the mold depending on the optical material, but in combination with materials with low adhesion to the mold, problems such as fusion with the mold and cans can be prevented. Can do.

  Further, in normal molding, the spreading method is determined by the shape of the molding material. For example, when a spherical molding material is placed on the mold center and molded, the molding material expands concentrically from the mold center. When this molding material is molded so as to have an irregular shape, it is necessary to regulate burrs, which makes it difficult to produce a mold.

However, according to the present embodiment, the molding material 41 is divided into the first optical material 41 ₁ and the second optical material 41 _2, and three spherical second materials are formed around the first optical material 41 ₁ . Having arranged the optical materials 41 _2, regulation of burrs becomes possible to produce easily die shape, the optical element of the profile can be easily obtained.
[Third Embodiment]
7 to 10 are diagrams showing the configuration of the optical element manufacturing apparatus according to the third embodiment.

In addition, the same code | symbol is attached | subjected and demonstrated to the member the same as that of 1st Embodiment, or equivalent.
In the present embodiment, after forming the first optical material 41 ₁ or in the middle molding, the second optical material 41 2 _(resin) was charged into a mold, and performs molded continuously.

FIG. 7 shows a cross-sectional view of the manufacturing apparatus 10 arranged in the molding chamber 13.
In the molding chamber 13, the oxygen concentration is set to 30 ppm or less by an inert gas.
In the optical element manufacturing apparatus 10, a mold block 40 is placed on a heating plate 33. At the top of the mold block 40, vertically movable first press shaft 36 ₁ and the second press shaft 36 ₂ is disposed. The first press shaft 36 ₁ is in contact with the first upper surface of the upper die 42 ₁ to be described later, the second press axis 36 ₂ is fixed to the upper die 42 of the _second.

Note that a cartridge heater (not shown) is incorporated in each of the heating plate 33 and the first and second press shafts 36 ₁ and 36 ₂ .
Further, around the mold block 40, a carry-in table 61 and a fixed table 62 are disposed via a heat insulating member 63 in a substantially symmetrical manner. The fixed base 62 is placed on the base plate 64.

Mold block 40 has a first upper die 42 ₁ and the second upper die 42 _2, a first lower die 43 ₁ and the second lower mold 43 _2, the sleeve 44. First and second upper die ₄₂ 1, 42 ₂ and the first and second lower mold ₄₃ 1, 43 _2, inside the sleeve 44, so that the respective molding surfaces 42a, 42b, 43a, 43 b are opposed The sleeve 44 is inserted from both ends.

First shaping surface 42a of the upper die 42 ₁ is formed in a shallow concave spherical. The molding surface 43a of the _first lower mold 431 is formed in a deep concave spherical shape. The second upper die 42 _second shaping surface 42b and the second shaping surface 43b of the lower mold 43 ₂ are both formed on the flat surface. Further, a guide 46 for guiding the _second optical material 412 is formed on the molding surface 43 b of the _second lower mold 432.

The first upper die 42 ₁ and the second and upper mold 42 _2, and can slide independently in the axial direction of the sleeve 44. A hole 44 a is formed in a side wall facing the sleeve 44 in a direction orthogonal to the mold center axis.

Moreover, this so as to face the hole 44a, the upper loading platform 61 a second optical material 41 ₂ plate-shaped is placed. Furthermore, the supply cylinder 65 is arranged a second optical material 41 ₂ on pressing secured base 62.

As a first optical material 41 _1, a glass spherical 6mm. The first optical material 41 _1, transition point of La based glass of 540 ° C..
As a second optical material 41 _2, using the processed resin (plate thickness of 2mm in the present embodiment) of any shape. The second glass transition point of the optical material 41 ₂ is 139 ° C..

Next, the molding process of the optical element according to the present embodiment will be described.
7, at the time of molding, raises the first and second press shaft ₃₆ 1, 36 _2, placing the first optical material 41 ₁ on the forming surface 43a of the lower die 43.

Then, the first optical material 41 ₁ and the first upper die 42 ₁ is in contact, and lowering the second upper die 42 ₂ until no height hinder the second loading of the optical material 41 _2.
In this state, placing the second optical material 41 ₂ to the carrying table 61.

Then, lowering until it contacts the press shaft 36 ₁ to the first upper die 42 _1. The pressing force at this time is 10 kgf or less.
Then, the heating plate 33 and the first press shaft 36 _1, by energizing the cartridge heater (not shown) was heated to 600 ° C., heating the first optical material 41 ₁ with heat transfer.

Furthermore, the first press shaft 36 ₁ is pressed until the first optical material 41 ₁ to a predetermined center thickness by a pressing pressure 50 kgf. After this press completed, the heating plate 33 and the first press shaft 36 _1, cooled to 180 ° C. a second molding temperature of the optical material 41 _2. The pressure during cooling is 30 kgf.

Next, the second press shaft 36 _2, by energizing the cartridge heater (not shown), heated to a molding temperature 180 ° C. a second molding temperature of the optical material 41 _2.
Furthermore, loading the second optical material 41 ₂ in the second mold surface 43b along the lower mold 43 _{and second} guide 46 in the supply cylinder 65.

Figure 8 shows the state after the loading from the left side of the second optical material 41 ₂ in the first optical material 41 _1.
In this state, while pressing the first upper mold 42 ₁ in the first press shaft 36 _1, to lower the second press axis 36 _2. Thus, the second upper die 42 ₂ is contacted second optical material 41 _2, to heat the second optical material 41 ₂ in the heat transfer to a predetermined molding temperature.

After the second temperature of the optical material 41 ₂ is stabilized, the second press shaft 36 ₂ to press the second optical material 41 ₂ having a thickness of 2mm by press pressure 40kgf until a thickness 1.2 mm.
Then, the second temperature of the press shaft 36 ₂ is set to 30 ° C., cooled while the holding pressure 15kgf at this temperature.

Then raised the second press shaft 36 _2, takes out the optical element 48 which is molded.
FIG. 9 shows the shape of the optical element 48 as a molded product. Further, FIG. 10 is an enlarged view of a portion A of FIG. 9 shows the first optical material 41 ₁ and the stationary state after the second optical material 41 _second press.

As shown in FIGS. 9 and 10, the second optical material 41 ₂ it is integrally joined to the first optical material 41 ₁ in the anchor effect (biting shape as anchor).
To increase the bonding strength at this time is made possible by roughening example the roughness of the first optical material 41 ₁ B surface.

As a method of roughening the roughness of the surface B, the first optical material 41 ₁ and preform convex, methods of using those rough roughness of the portion corresponding to the B side thereof. According to the present embodiment, the shape accuracy of the optical functional surface of the molded optical element 48 is a shape that satisfies the design specifications.

According to this embodiment, the molding material 41 is divided first optical material 41 ₁ and the second optical material 41 _2, since it is press-molded in the same mold arrangement, it is possible to perform highly accurate molding it can. Furthermore, using a glass spherical as the first optical material 41 _1, since a plate-shaped resin as the second optical material 41 _2, while maintaining the shape accuracy of the optical function surface of the optical element 48, the outer periphery thereof The portion (edge portion) can be formed thin.

It is sectional drawing which shows the outline | summary of the manufacturing apparatus of the optical element of 1st Embodiment. It is a top view which follows the II-II line same as the above. It is sectional drawing which shows the structure of a metal mold block. It is a figure which shows the state which clamped the 1st optical material between the upper mold | type and the lower mold | type. It is a figure which shows the state press-molded to the middle. It is a figure which shows the state by which the optical element was finally shape | molded. It is sectional drawing of the metal mold | die block used for the manufacturing method of the optical element of 2nd Embodiment. It is a top view which follows a VI-VI line same as the above. It is sectional drawing which shows the structure of the manufacturing apparatus of the optical element of 3rd Embodiment. It is a figure which shows the state which carried in the 2nd optical material from the left-right side to the 1st optical material. It is a figure which shows the shape of an optical element. It is an A section enlarged view same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical element manufacturing apparatus 11 Apparatus mount 13 Molding chamber 16 Entrance shutter 18 Exit shutter 21 Press stage 33 ₁ Upper heating plate 33 ₂ Lower heating plate 34 ₁ Upper molding plate 34 ₂ Lower molding plate 35 ₁ Upper cartridge heater 35 ₂ Lower cartridge Heater 36 Air cylinder 36 ₁ First press shaft 36 ₂ Second press shaft 40 Mold block 41 ₁ First optical material (first member)
41 ₂ 2nd optical material (2nd member)
41 ₂ a chamfered portion 41 ₂ b chamfered portion 42 upper mold 42 a molded surface 42 b molded surface 42 ₁ first upper mold 42 ₂ second upper mold 43 lower mold 43 a molded surface 43 b molded surface 43 c concave surface 43 ₁ first lower Mold 43 _2nd lower mold 44 Sleeve 44a Hole 45 Outer diameter regulating ring 46 Guide 48 Optical element 50 Fusion mark 52 Dividing piece 61 Loading table 62 Fixing table 63 Heat insulating member 64 Base plate 65 Supply cylinder

Claims (5)

In the method of manufacturing an optical element, a molding material is disposed between a pair of upper and lower molds facing each other, the molding material is heated and softened, and press molding is performed to obtain an optical element.
The molding material has a first member and at least three second members,
The first member and the at least three second members are glasses, and the compositions of the glasses are different.
Placing the first member in the center of the mold;
The at least three second members are divided and arranged in a direction intersecting the mold center axis,
By pressing the first member and the at least three second members, an optical function surface is formed by the first member, and the optical function surface is integrally formed by the at least three second members. Forming and joining in an independent state to the first member while dividing the at least three second members;
A method for manufacturing an optical element. The method of manufacturing an optical element according to claim 1, wherein the at least three second members have a linear expansion coefficient smaller than that of the first member. The at least three second members are supplied into the mold after molding the first member, and after molding the first member, the at least three second members are molded while pressing and holding the upper mold. the method of manufacturing an optical element according to claim 1 or 2, characterized in that. The first member arranged at the mold center between a pair of the upper mold and the lower mold facing each other, and the first member and the glass are different from each other in the composition of the glass, and divided in the direction intersecting the mold center axis a molding material having at least three second members arranged,
An outer diameter regulating member disposed on an outer peripheral side of the at least three second members;
Press means for press-molding the heat-softened molding material,
Wherein in a state where the first member by molding the optical function surface in the integrally molded around the optical functional surface on at least three of the second member, independent while the divided at least three of the second member Joining to the first member,
An optical element manufacturing apparatus.   A central optical functional unit having an optical functional surface;
  And at least three edge portions formed around the optical function portion,
  The optical function portion and the at least three edge portions are glasses, and the compositions of the glasses are different.
  The at least three edge portions are joined to the optical function surface portion in a divided and independent state,
  An optical element.