JPH0742122B2 - Optical element molding equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a molding device for an optical element.

[Conventional technology]

Conventionally, when manufacturing optical elements such as lenses, prisms, and filters, the molding material is heated and softened without post-processing such as polishing the optical elements, and the molding material is shaped into a shape corresponding to the desired optical element shape. Press molding is performed by a mold. As an apparatus used in such a molding method, for example, JP-A-59-152229 and JP-A-60-118641 are used.
What is disclosed in Japanese Patent Publication is known.

The apparatus disclosed in Japanese Patent Laid-Open No. 59-152229 prepares a large number of molding materials provided between a pair of upper and lower molds, sequentially heats them, and conveys them to the lower side of the cylinder. It is formed by pressing the upper mold. Further, in the device disclosed in Japanese Patent Laid-Open No. 60-118641, after the outer periphery of a molding material is locked to a ring-shaped body mold to heat and soften it, the body mold is placed between a pair of upper and lower molds. It is inserted into and is pressed.

[Problems to be Solved by the Invention] However, in the apparatus disclosed in Japanese Patent Laid-Open No. 59-152229, a large number of upper and lower mold sets are required, and particularly when a mold with a high manufacturing cost such as an aspherical mold is used. , The manufacturing cost of the optical element has become expensive. In addition, the aspherical type is technically more difficult to manufacture and evaluate than the spherical type, and requires more than three times as many man-hours, and it is almost impossible to use the same type when manufacturing a plurality of types. It is possible. Therefore, there is a problem in that the performance of the obtained optical element varies when a large number of upper and lower mold sets are used. On the other hand, in the device disclosed in Japanese Patent Laid-Open No. 60-118641, when a molding material having a large diameter (for example, a diameter of 15 mm or more in the case of a lens) is locked in the barrel, viscous flow deformation due to uneven heating or self-weight is caused. Occurred, and stable molding could not be performed.

The present invention has been made in view of these problems, and can perform stable molding at low cost, and is particularly suitable for molding an aspherical optical element or a large-diameter optical element. An object is to provide a device for molding a device.

[Means for solving problems]

In order to solve such conventional problems, the present invention is an optical element molding apparatus for molding an optical element by press molding a molding material heated to a predetermined temperature with a molding die, wherein the molding die is , A fixed-position mold provided at a fixed position and a plurality of transfer molds that are sequentially transferred to stop facing the fixed position mold, and the molding material is placed on the transfer mold before press molding. At the same time, after the press molding, the optical element is placed, and the fixed position mold and the transfer mold are provided so as to be relatively movable toward and away from each other in the axial direction of the mold.

[Action]

According to the optical element molding apparatus having the above-described configuration, the molding material is placed on the plurality of transport dies, and the molding material is heated to soften the molding material. Then, the transport die is sequentially transported to a position facing the fixed position die, stopped at that position, and at least one of the fixed position die or the transport die is moved in the axial direction of the die to perform pressure molding. After the press molding is completed, the obtained optical element is placed on the carrying mold and carried from a position facing the fixed position mold to another position. After that, the optical element is gradually cooled and taken out from the carrying mold.

By carrying out such a molding process for a plurality of conveying dies, it is possible to perform inexpensive and stable molding.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the molding apparatus of the present invention, in which a plurality of transfer dies 21 to 24 are mounted on a transfer table 1 at predetermined intervals in a straight line. It is placed. Each of these transport types 21 ~
The molding surfaces 21a to 24a, which are spherical optical function surfaces, are formed in the central portion of the 24 toward the upper side. In addition, each transport type 21
〜 24, substantially cylindrical guide members 31 to 34 coaxially with the conveying dies 21 to 24 are integrally fixed by fitting so as to surround the central portion where the molding surfaces 21a to 24a are formed from the outer periphery. It is set up. The guide members 31 to 34 have a tapered portion on the outer periphery of the upper end thereof.
31a to 34a are formed.

On the other hand, above the transport die 22 is located, a cylindrical fixed position die 4 having a molding surface 4a of an aspherical optical function surface formed at the lower end.
However, it is provided so as to be movable in the axial direction by a drive device (not shown). In addition, a taper portion 5a having the same inclination angle as the taper portions 31a to 34a of the guide members 31 to 34 and fittable with the taper portions 31a to 34a is provided on the outer periphery of the lower end outer peripheral portion of the fixed position die 4. A substantially cylindrical guide member 5 formed on
However, the position fixing mold 4 is slidably fitted in the position fixing mold 4 coaxially. The guide member 5 is provided so as to be movable in the axial direction similarly to the fixed position die 4.

In addition, 6 is a molding material made of a glass material, and 6a is an optical element formed by pressing the molding material 6.

Next, a process of molding the optical element by the molding device having such a configuration will be described.

First, at room temperature and in the air, the molding material 6 is placed in the space surrounded by the transport dies 21-24 and the guide members 31-34, and the molding material 6 is placed on the transport dies 21-24. Next, the carrier 21
-24 are loaded into a heating furnace (not shown) and heated to a predetermined temperature to soften the forming material 6. Here, in the heating furnace, a heating wire is arranged inside as a heating means and a conveying means is provided so that the conveying dies 21 to 24 can be conveyed. In addition, in order to prevent the inside of the heating furnace from being oxidized by the transfer molds 21 to 24 or the like, it is preferable that an inert gas such as nitrogen gas, a reducing gas, or a non-oxidizing atmosphere such as a vacuum be used. .

Next, the heated transfer molds 21 to 24 are transferred below the position fixing mold 4 by the transfer table 1. And first, the transport type 22
When 4 is conveyed to a position facing the fixed position mold 4, the conveyance is stopped. After that, the upper guide member 5 is lowered to fit the guide member 5 into the lower guide member 34. At this time, the taper portion 5a of the guide member 5 and the taper portion 34a of the guide member 34 are fitted to each other, and the two guide members 5 and 34 are brought into a centered state.

In this state, the position fixing mold 4 is slid down in the guide member 5 and the molding material 6 is pressed to move the position fixing mold 4 and the conveying mold 24.
The optical element 6a having a shape surrounded by the guide member 34 is obtained.

After the completion of the press molding, the position fixing die 4 and the guide member 5 are lifted and separated from the conveying die 24 and the guide member 34. After that, the transport die 24 on which the optical element 6a is mounted starts to be transported again (on the right side in FIG. 1), and is gradually cooled. After the gradual cooling, the optical element 6a is taken out from the carrier die 24.

The above steps are sequentially repeated from the carrier die 24 to the carrier die 21, and FIG. 1 is a diagram at the time of press molding by the carrier die 22.

If a large number of carrier dies are prepared and molding is performed, molding can be performed with a short tact, inexpensive molding can be performed stably, and mass production becomes possible. According to the first embodiment described above, a single-sided aspherical / biconcave lens with an aperture of 18 mm (R lower = 5
0.317mm, approximate curvature R on the aspheric axis = 32.822mm, wall thickness 1.8
mm, glass type SF7) could be continuously molded with a takt time of 3 minutes.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention, showing an example in which a heater 7 and a thermocouple 8 are incorporated in a position fixing die 41.
The guide members 35 and 51 are the same as those shown in FIG. 1, and the molding surface 41a of the position fixing mold 41 is an aspherical mold, and the molding surface 25a of the conveying mold 25 is a spherical mold. 6b is an optical element.

According to this embodiment, the mold temperature of the fixed position mold 41 can be raised during the press molding, and the molding time can be shortened. Further, the temperature on the molding surface is more stable than that of the whole heating method shown in the first embodiment, and the quality and yield can be improved.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention, showing an example in which a cooling rod 9 is further incorporated in the fixed position mold 42 in addition to the heater 7 and the thermocouple 8. The cooling rod 9 is composed of a pipe into which a cooling medium made of a liquid such as water, oil or mercury can flow. The guide members 36 and 52 are the same as those shown in FIG. 1, and the molding surface 42a of the position fixing die 42 is an aspherical surface, and the molding surface 26a of the conveying die 26 is a flat surface. 6c is an optical element.

According to this embodiment, the mold temperature of the position-fixing mold 42 can be arbitrarily controlled during the press molding, and the quality and the yield can be further improved as compared with the second embodiment.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention, in which the position fixing die 43 and the guide member 53 cannot be moved in the axial direction unlike the first to third embodiments, and the complete fixing is not possible. It is fixed to. On the other hand, the transfer dies 27 and 27 and the guide member 37 are movable in both directions by the movable shaft 10 connected to a drive device (not shown). The molding surface 43a of the position fixing mold 43 is an aspherical mold, and the molding surface 27a of the transfer mold 27 is a spherical mold.

(Fifth Embodiment) FIG. 5 shows a fifth embodiment of the present invention.
Is arranged above and the fixed position mold 44 is arranged below. The carrier type 28 is a guide member fixed to the carrier 1.
The forming material 6 is screwed to the 38, and is supported by the conveying die 28 via the guide member 38. The fixed position die 44 and the guide member 54 are each movable in the axial direction. Further, the molding surface 28a of the transfer die 28 is a spherical surface type, and the molding surface 44a of the position fixing die 44 is an aspherical surface type.

In the first to fifth embodiments, the axial direction of the mold is the vertical direction, but the present invention is not limited to this embodiment, and the axial direction of the mold may be the horizontal direction.

Further, the transport type transport method is not limited to the line type as shown in FIG. 1, but may be a circular type as shown in FIG. 6, for example. In FIG. 6, reference numeral 11 denotes a turntable that is rotatably driven and can be stopped. On the turntable 11, a plurality of transfer dies 20 are mounted in the circumferential direction. A fixed position mold 40 is provided above the position where the carrier mold 20 stops.
Is movably provided in the axial direction. Fixed position type 40
Is to perform press molding by operating in association with movement and stop of the transfer mold 20.

On the other hand, not only the line type and the circular type, but also the conveying type may be conveyed in the vertical direction.

〔The invention's effect〕

As described above, according to the molding apparatus of the present invention, the molding die is composed of the fixed position mold and the plurality of carrier molds, and the molding material and the optical element are placed on the carrier mold. The number of position-fixing dies is small, and it is possible to perform inexpensive and stable molding. In particular, if the aspherical surface type is a fixed position type, it has a great effect in terms of cost and quality, and is most suitable for molding an aspherical optical element or an optical element having a large diameter.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of a molding apparatus of the present invention, FIG. 2 is a vertical sectional view showing an essential part of the second embodiment, and FIG. 3 is an essential part of a third embodiment. FIG. 4 is a vertical sectional view showing an essential part of the fourth embodiment, FIG. 5 is a vertical sectional view showing an essential part of the fifth embodiment, and FIG. 6 is another example of a transfer type transfer method. FIG. 4,40,41,42,43,44 …… Fixed position type 6 …… Molding material 6a, 6b, 6c …… Optical element 20,21,22,23,24,25,26,27,28 …… Transfer Type.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyokazu Hosaka 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Inventor Takeaki Nakamura 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd.

Claims (1)

[Claims] 1. An optical element molding apparatus for molding an optical element by press-molding a molding material heated to a predetermined temperature with a molding die, wherein the molding die is fixed in position and fixed in position. The mold is composed of a mold and a plurality of conveying dies that are sequentially conveyed so as to be opposed to the position-fixing mold, and the molding material is placed on the conveying mold before the press molding and the optical element is placed after the press molding. An apparatus for molding an optical element, characterized in that a fixed-position mold and a transfer mold are mounted so as to be relatively movable toward and away from each other in the axial direction of the mold.