JP2010105889A - Method for manufacturing optical device and press molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device manufacturing method and a press molding apparatus by which the optical device having a desired shape is stably manufactured by extending the service life of a molding surface of a mold in the press molding apparatus. <P>SOLUTION: The method for manufacturing the optical device, which has a step of assembling an upper die 21 and a lower die 22 into a mold to press-mold a glass gob G, comprises: a detecting step of detecting the surface state of the molding surfaces 23, 24 of the upper die 21 and the lower die 22 after the optical device M is taken out; a determination step of determining whether the surface state of the upper die 21 and/or the lower die 22 is allowable or not; and a cleaning step of taking out the upper die 21 and/or the lower die 22 having the surface exhibiting a non-allowable state to clean the molding surfaces 23, 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical element manufacturing method and a press molding apparatus.

  In recent years, optical lenses formed into a predetermined shape have been used for lenses of optical elements such as digital cameras. In order to manufacture this optical lens with high accuracy and in large quantities, for example, the following methods are known. That is, first, a molten glass is used to form a glass lump (hereinafter referred to as a preform) having a shape approximate to the shape of the optical lens, and then the preform is press-molded with a mold and hot-worked. .

  According to this method, since an optical lens is molded from molten glass through a preform, the optical lens is manufactured from a plate-like glass through a multi-step process such as cutting, processing, pressing, grinding, and polishing. In comparison, the lead time can be shortened, and a decrease in yield due to processing defects can be suppressed. As a result, the cost can be greatly reduced.

  Here, as an optical element manufacturing apparatus for manufacturing an optical element, for example, an optical element including a press molding unit that performs press molding on a mold and a cleaning unit that cleans the mold from which the optical element has been removed. Is disclosed (see Patent Document 1).

In this optical element manufacturing apparatus, after press molding, the mold from which the optical element has been taken out is sequentially conveyed to a cleaning means, and the mold is cleaned by means such as etching, polishing, or ultrasonic cleaning.
JP 63-064930 A

  However, the optical element manufacturing apparatus disclosed in Patent Document 1 automatically shortens the life of the mold because the mold from which the optical element is taken out is automatically conveyed to the cleaning means. Here, in order to suppress the deterioration of the molding surface, it may be possible to reduce the frequency of washing, but unless the frequency is set appropriately, it depends on deposits on the molding surface, scratches on the molding surface, and alteration of the molding surface. There is a concern about the deterioration of the quality of the optical element.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to extend the life of the molding surface of a mold in a press molding apparatus and stably provide an optical element having a desired shape. An object of the present invention is to provide an optical element manufacturing method and a press molding apparatus that can be manufactured.

  In order to solve the above-mentioned problems, the present inventors have determined whether or not the surface state of the molding surface of the upper mold and / or the lower mold is in an unacceptable state as a result of repeated earnest test research. Is formed on the molding surface of the mold while the frequency of cleaning the mold is reduced by removing the mold in an unacceptable state and cleaning the molding surface of the upper mold and / or the lower mold. The present inventors have found that the adhering matter and scratches and / or the deteriorated portion of the molding surface are maintained in an allowable state, and the present invention has been completed. More specifically, the present invention provides the following.

  (1) An optical element manufacturing method for manufacturing an optical element by assembling an upper mold and a lower mold into a mold and press-molding a glass lump, and molding surfaces of the upper mold and the lower mold after the optical element is taken out A detection step of detecting a surface state of the upper die and / or a determination step of determining whether or not the surface state of the upper die and / or the lower die is in an unacceptable state; Or the optical element manufacturing method which has the cleaning process which takes out a lower mold | type and cleans the said molding surface.

  (2) The optical element manufacturing method according to (1), wherein the surface state is a deposit on the molding surface, a scratch on the molding surface, and / or an alteration of the molding surface.

  (3) The optical element manufacturing method according to (1) or (2), wherein a plurality of the molds are used, and whether or not the molding surface needs to be cleaned is determined independently for each of the molds.

  (4) The optical element manufacturing method according to (3), wherein the press molding is continuously performed without cleaning the upper mold and the lower mold whose surface states are not in an unacceptable state.

  (5) About the metal mold | die judged as the non-permissible state by the said determination process, it is further judged whether it is a replacement required state, and when it determines with a replacement required state, a new metal mold | die is not performed but the said cleaning is not performed. The optical element manufacturing method according to any one of (1) to (4), including a step of exchanging with the optical element.

  (6) An optical device using an optical element manufactured by the optical element manufacturing method according to any one of (1) to (5).

(7) Press molding having press molding means for assembling an upper mold and a lower mold into a mold and performing press molding to take out an optical element; and a cleaning means for cleaning the molding surfaces of the upper mold and the lower mold. A device,
Detecting means for detecting a surface state of the molding surfaces of the upper mold and the lower mold;
Determining means for determining whether or not the surface condition is in an unacceptable state, taking out the upper mold and / or the lower mold for which the surface condition has been determined to be in an unacceptable state, and performing cleaning by the cleaning means; , Having a press forming apparatus.

  (8) The press forming apparatus according to (7), wherein the detection unit detects, as a surface state of the molding surface, a deposit on the molding surface, a scratch on the molding surface, and / or an alteration of the molding surface.

  (9) The press molding apparatus according to (8), wherein a plurality of the molds are provided, and the determination unit independently determines the cleaning of the plurality of molds.

  (10) An optical element manufacturing apparatus having the press molding apparatus according to any one of (7) to (9).

  (11) An optical device manufacturing apparatus that manufactures an optical device using the optical element manufactured by the optical element manufacturing device according to (10).

  According to the present invention, it is determined whether or not the surface state of the molding surface of the upper mold and / or the lower mold is in an unacceptable state, the mold having the surface state in an unacceptable state is taken out, and the upper mold and / or By cleaning the molding surface of the lower mold, the frequency with which the mold is cleaned is reduced, while the deposits and scratches formed on the molding surface of the mold, and / or the altered part of the molding surface is removed. Kept in an acceptable state. For this reason, the lifetime of the molding surface of the mold in the press molding apparatus can be extended, and an optical element having a desired shape can be stably produced.

  The optical element manufacturing method of the present invention is an optical element manufacturing method including a step of assembling an upper mold and a lower mold into a mold and press-molding a glass lump, and the upper mold and the lower mold after taking out the optical element A detecting step for detecting the surface state of the molding surface of the mold, a determining step for determining whether or not the surface state of the upper mold and / or the lower mold is in an unacceptable state, and the upper in which the surface state is in an unacceptable state A cleaning step of removing the mold and / or the lower mold and cleaning the molding surface;

  Further, the press manufacturing apparatus of the present invention includes a press molding means for assembling an upper mold and a lower mold into a mold and performing press molding to take out an optical element, and cleaning for cleaning the molding surfaces of the upper mold and the lower mold. Means for detecting the surface state of the molding surfaces of the upper mold and the lower mold, and determining means for determining whether or not the surface state is in an allowable state. Have

  Hereinafter, embodiments of the press molding apparatus and the optical element manufacturing method according to the present invention will be described in detail. However, the present invention is not limited to the following embodiments at all, and appropriately within the scope of the object of the present invention. Can be implemented with changes. In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the meaning of invention is not limited.

<First Embodiment>
In the first embodiment of the present invention, the upper mold 21 and the lower mold 22 are assembled into a mold, the glass lump G is press-molded to form the optical element M, and the upper after the optical element M is taken out. An optical element manufacturing method comprising: a detection process for detecting the surface states of the molding surfaces 23 and 24 of the mold 21 and the lower mold 22; and a cleaning process for cleaning the molding surfaces 23 and 24 of the upper mold 21 and the lower mold 22. It is. 1A to 1P are perspective views showing a preferable example of a series of operations of the press molding apparatus 1.

[Press forming process]
In the press molding process, as shown in FIGS. 1A to 1B, after the glass block G is supplied to the lower mold 22 of the mold, the upper mold 21 and the lower mold 22 are molded as shown in FIGS. 1C to 1E. Assemble and press-mold. Here, the mold to which the glass block G is supplied has an upper mold 21 and a lower mold 22. The shapes of the molding surfaces 23 and 24 of the upper die 21 and the lower die 22 are appropriately selected depending on the shape of the optical element to be produced. In particular, the lower die 22 is a shape that is expanded toward the opening direction. Is preferred. Thereby, since positioning with respect to the lower mold | type 22 of the glass lump G becomes easy, the shape defect in the produced optical element can be reduced. The upper mold 21 and the lower mold 22 are preferably formed by forming a protective film on the molding surfaces 23 and 24. Thereby, it becomes difficult to generate | occur | produce a damage | wound on the molding surfaces 23 and 24 by press molding, and since it becomes easy to keep a damage | wound in an allowable state, the replacement frequency of a metal mold | die can be reduced.

  On the other hand, the supply means 10 for supplying the glass block G to the lower mold 22 can be appropriately selected according to the size of the glass block G to be supplied, the shape of the mold, and the like. For example, as shown in FIG. The suction means 11 that sucks and holds the glass lump G by the suction force of the pump 12 may be used, and the outflow nozzle that supplies the molten glass to the lower mold 22 may be used as the supply means 10.

  The means for assembling the upper mold 21 and the lower mold 22 into the mold is not particularly limited. For example, as shown in FIG. 1E, the upper mold 21 is held by a holder 51 and is not shown. The upper mold 21 is transferred to the upper side of the lower mold 22 supplied with the glass lump G using a motor. As shown in FIGS. 1C to 1E, the upper die 21 may be inserted into the barrel die 25 after the barrel die 25 is provided using the holder 52 so as to surround the lower die 22. Thereby, since the movement range of the upper mold | type 21 at the time of a press is restrict | limited, the glass lump G can be easily shape | molded in a desired shape.

  Then, as shown in FIG. 1F, the glass lump G is pressed through the upper mold 21 using the pressing means 31 while the glass lump G is softened by heating with the heating means 93 to press-mold the glass lump G. . Thereby, the glass lump G is shape | molded in a desired shape.

  After the glass lump G is press-molded, as shown in FIG. 1, after the pressing means 31 is driven in the reverse direction (FIG. 1G), the mold is disassembled into the upper mold 21 and the lower mold 22 (FIGS. 1H and 1I). The optical element M is taken out (FIG. 1J). Here, as shown in FIG. 1I, the upper mold 21 is preferably inverted so that the molding surface 23 is on the upper side. Thereby, since the detection process of the surface state of the upper mold | type 21 and the lower mold | type 22 shown below can be performed with the one detection means 60, the press molding apparatus 1 can be simplified. The means for reversing the upper mold 21 is not particularly limited, and for example, a motor 53 attached to the holder 51 can be used.

[Detection process]
In the detection step, as shown in FIGS. 1K and 1L, the surface states of the molding surfaces 23 and 24 of the upper mold 21 and the lower mold 22 after the optical element M is taken out are detected. Thereby, since the surface state of the molding surfaces 23 and 24 is acquired as information in the press molding apparatus 1, it becomes possible to sort the upper mold 21 and the lower mold 22 in the surface state. Here, the detection means 60 for detecting the surface state is appropriately selected depending on the type of the surface state to be detected. For example, a camera having a magnifying glass can be used. In addition, the surface state to be detected in the detection step is preferably an adherent to the molding surfaces 23 and 24, a scratch on the molding surfaces 23 and 24, and / or an alteration of the molding surfaces 23 and 24. For example, the thickness of the protective film formed on the molding surfaces 23 and 24 may be detected.

[Judgment process]
In the determination step, it is determined whether or not the surface states of the molding surfaces 23 and 24 detected in the detection step are in an unacceptable state, and it is determined whether or not to perform a cleaning step described below. Accordingly, the cleaning process is performed only for the mold to be cleaned, and the frequency of cleaning the mold is reduced. Therefore, the deterioration of the molding surfaces 23 and 24 of the mold is reduced, and the life of the mold is increased. Can be long.

  Here, it is preferable to determine whether or not the molding surfaces 23 and 24 need to be cleaned independently for each of a plurality of molds. As a result, the molds are individually cleaned according to the deposits and scratches on the molding surface, which differ depending on the mold, or the state of the molding surface deterioration, and the cleaning of the molds that do not require cleaning is reduced. Therefore, the life of the mold can be extended.

  At this time, when one surface state of the upper die 21 and the lower die 22 is not in the non-permissible state, the upper die 21 and / or the lower die 22 that are not in the non-permissible state are in the non-permissible state without being cleaned. Only the upper mold 21 and / or the lower mold 22 may be cleaned and the press molding may be continued. In particular, when the surface states of the upper mold 21 and the lower mold 22 are both in an allowable state, it is preferable to continue the press molding as it is without cleaning the upper mold 21 and the lower mold 22. Thereby, since the time which performs the cleaning process with respect to the upper mold | type 21 and / or the lower mold | type 22 is shortened, the production efficiency of the optical element M using the press molding apparatus 1 can be improved more.

  The determination means 70 for determining the surface state of the molding surfaces 23 and 24 is appropriately selected depending on the detected information state of the surface state. For example, an image recognition unit is used and the limit state registered in advance is used as a reference. The surface states of the molding surfaces 23 and 24 can be determined, and the switch S of the cleaning means 80 described below can be turned on based on the determination result.

  In this embodiment, the determination means 70 determines whether or not cleaning is necessary based on whether or not the molding surfaces 23 and 24 of the mold are in an unacceptable state. If the depth of the mold is deep or the surface of the mold is significantly deteriorated, the mold may not be used in the press molding process only by performing the cleaning process using the cleaning means 80. Therefore, the determination means 70 determines whether or not the mold determined to be in an unacceptable state is in a state that requires replacement. If it is determined that the replacement is required, a new mold is not performed without performing a cleaning process. It is also possible to include a process of exchanging with.

[Cleaning process]
In the cleaning step, as shown in FIGS. 1L to 1O, the upper mold 21 and / or the lower mold 22 whose surface state is in an unacceptable state are taken out and the molding surfaces 23 and 24 are cleaned. As a result, the deposits and scratches formed on the molding surfaces 23 and 24 of the mold and / or the deteriorated portion of the molding surface are maintained in an allowable state, so that the optical element M having a desired shape can be stably formed. Can be produced.

  Here, in the cleaning process, the deposit formed on the molding surfaces 23 and 24 and the deteriorating portion of the molding surfaces 23 and 24 were washed, and the deposit and scratches were formed on the molding surfaces 23 and 24. The upper die 21 and / or the lower die 22 and / or the replacement step of exchanging the upper die 21 and / or the lower die 22 in which at least a part of the molding surfaces 23, 24 is altered have at least one of the cleaning means. It is preferable to perform both 80 and the exchange means (not shown) in the cleaning process. As a result, the optical element M is fogged due to the deposits on the molding surfaces 23 and 24 and / or the altered portions of the molding surfaces 23 and 24, and the optical element M is defective due to the deposits and / or scratches on the molding surfaces 23 and 24. Therefore, the optical element M can be used without performing a post-process such as polishing.

  Among these, the cleaning means 80 for performing the cleaning process is appropriately selected according to the composition of the glass lump G. For example, as shown in FIGS. 1L to 1O, the cleaning rod 83 is brought into contact with the molding surfaces 23 and 24 and turned. The cleaning stick 83 and / or the molding surfaces 23 and 24 may be rotated using the table 91 and the motor 81 to wipe off the deposits and altered parts, and the deposits and alterations may be ejected by jetting liquid onto the molding surfaces 23 and 24. You may wash away the part. In particular, by using the cleaning rod 83 as a cleaning means for the molding surface on which the protective film is formed, the molding surfaces 23 and 24 are protected by the protective film when the cleaning rod 83 and the molding surfaces 23 and 24 come into contact with each other. It is possible to reduce a decrease in the life of the mold due to the use of the cleaning rod 83. Moreover, although an exchange means is suitably selected according to the shape of a metal mold | die, etc., a metal mold | die can be replaced | exchanged, for example using a holder.

  The mold cleaned by the cleaning process is transferred to the position where the glass lump G is supplied to be used again in the above-described press molding process together with the mold that has not been cleaned (FIG. 1P). Here, although the transfer means 90 which transfers a metal mold | die is not specifically limited, For example, the holder 51 provided with the motor which is not shown in figure can be used.

[Production of optical equipment]
The optical element M (for example, an optical lens) is manufactured by the press molding process described above. Moreover, it is also preferable to manufacture an optical apparatus using the optical element M manufactured by the optical element manufacturing apparatus having the press molding apparatus 1.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to a following example.

  As a mold for press molding, a mold having an upper mold and a lower mold, each of which has a base made of WC, and a protective film made of a Pt—Ir alloy on the molding surface is used. The upper mold and the lower mold were attached to a predetermined holder of the press molding apparatus. Here, a body mold was provided so as to surround the lower mold when performing press molding. Then, the glass block was supplied to the lower mold of the mold using the suction means connected to the pump as the supply means, and then the motor for driving the upper mold was turned on, and the upper mold was transferred to the upper side of the lower mold. Next, the upper mold was inserted into the barrel mold using the pressing means while the glass lump was softened by heating with the heating means, and the upper mold and the lower mold were assembled into the mold. Here, the upper mold was further lowered using a pressing means to press the glass lump, and the glass lump was press-molded. After press molding, the pressing means was driven in the opposite direction to disassemble the mold into an upper mold and a lower mold, and the optical element was taken out.

  After taking out the optical element, the upper mold is turned over so that the molding surface is on the upper mold, and the upper and lower mold molding surfaces are attached to the molding surface by using a camera equipped with a magnifying glass as a detection means. And the state of the part which changed in quality was detected, and the image of the molding surface was sent to the image recognition unit which is a judgment means. In the image recognition unit, whether or not the molding surface is in the non-permitted state is independently determined for each of the plurality of molds based on the information based on the limit state registered in advance. Here, when the surface state of both the upper mold and the lower mold was in an allowable state, the upper mold and the lower mold were used for press molding as they were without being cleaned. On the other hand, the upper die and / or the lower die whose surface state is in an unacceptable state are taken out from the press molding apparatus, and the washing bar and the molding surface are rotated while the washing bar is in contact with the molding surface, and the molding surface is changed. Cleaned.

  The mold cleaned by performing the cleaning process was attached to a predetermined holder of the press molding apparatus together with the mold not cleaned, and used again for the press molding process.

  As a comparative example, the same test as in the example was performed when the molding surface was washed each time press molding was performed.

  As a result, when the molding surface is washed when the surface condition of the upper die and / or the lower die is not in an allowable state, the protective film for the molding surface is compared with the case where the molding surface is washed each time press molding is performed. The life of the film was improved by 30%, and the occurrence of molding defects such as cracks and fogging in the molded optical element was reduced by 20%. When the molding surfaces of the molds of Examples and Comparative Examples were compared, the frequency with which the molds were cleaned was reduced, and deposits and scratches formed on the molding surfaces of the molds were generated on the molding surfaces. It can be seen that since the altered portion is maintained in an allowable state, the life of the molding surface can be extended and an optical element having a desired shape can be stably produced.

It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment. It is a perspective view which shows an example of operation | movement of the press molding apparatus in 1st embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Press molding apparatus 10 Supply means 11 Adsorption means 12 Pump 21 Upper mold | type 22 Lower mold | type 23, 24 Molding surface 25 Body mold | type 31 Press means 51, 52 Holder 53, 81 Motor 60 Detection means 70 Judgment means 80 Cleaning means 83 Cleaning rod
90 Transfer means 91 Turntable 93 Heating means G Glass block M Optical element S Switch

Claims (11)

An optical element manufacturing method for manufacturing an optical element by assembling an upper mold and a lower mold into a mold and press-molding a glass lump,
A detection step of detecting the surface state of the molding surfaces of the upper mold and the lower mold after taking out the optical element;
A determination step of determining whether the surface state of the upper mold and / or the lower mold is in an unacceptable state;
An optical element manufacturing method including a cleaning step of removing the upper mold and / or the lower mold whose surface state is in an unacceptable state and cleaning the molding surface.   2. The optical element manufacturing method according to claim 1, wherein the surface state is a deposit on the molding surface, a scratch on the molding surface, and / or an alteration of the molding surface. Using a plurality of the molds,
The optical element manufacturing method according to claim 1, wherein the necessity of cleaning the molding surface is determined independently for each of the molds.   The optical element manufacturing method according to claim 3, wherein the press molding is continuously performed without cleaning the upper mold and the lower mold whose surface states are not in an unacceptable state.   For the mold that is determined to be in an unacceptable state in the determination step, it is further determined whether or not the replacement is required. If it is determined that the replacement is required, the mold is replaced with a new mold without performing the cleaning. The optical element manufacturing method in any one of Claim 1 to 4 including a process.   An optical apparatus using an optical element manufactured by the optical element manufacturing method according to claim 1. A press molding apparatus having press molding means for assembling an upper mold and a lower mold into a mold and performing press molding to take out an optical element; and a cleaning means for cleaning the molding surfaces of the upper mold and the lower mold. And
Detecting means for detecting a surface state of the molding surfaces of the upper mold and the lower mold;
Determining means for determining whether or not the surface condition is in an unacceptable state, taking out the upper mold and / or the lower mold for which the surface condition has been determined to be in an unacceptable state, and performing cleaning by the cleaning means; , Having a press forming apparatus.   The press forming apparatus according to claim 7, wherein the detecting unit detects a deposit on the forming surface, a flaw on the forming surface, and / or an alteration of the forming surface as a surface state of the forming surface. A plurality of the molds are provided,
The press molding apparatus according to claim 8, wherein the determination unit independently determines the cleaning of the plurality of molds.   An optical element manufacturing apparatus comprising the press molding apparatus according to claim 7.   An optical device manufacturing apparatus that manufactures an optical device using the optical element manufactured by the optical element manufacturing device according to claim 10.

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