JP2011084418A - Method and apparatus for manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing an optical element, capable of reducing cracking, segregation and haze of the molded optical element and increasing dimensional reproducibility of the optical element. <P>SOLUTION: In the method for manufacturing the optical element, the optical element L is manufactured by pressing a glass G. The method includes a step of successively moving a molding die 2 comprising an upper die 21 and a lower die 23 through a temperature-raising stage 11, a pressing stage 12 and a temperature-lowering stage 13 and stopping the molding die 2 at each stage to raise the temperature, press and lower the temperature of the glass G, respectively, inside the molding die 2. The moving and stopping of the molding die 2 are performed by moving a contact part 43a that contacts the molding die 2 while keeping a temperature difference of within 20°C between the contact part 43a and a contacted site of the molding die 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Conventionally, a glass molded body has been manufactured by polishing a glass cut out from a plate glass into a shape approximate to a glass molded body, and then heat-molding the polished product. However, when producing an optical element such as a lens, this method increases the polishing cost of the glass material. Therefore, a method of forming an optical element such as a lens by press-molding the raw glass using a mold is used.

  Here, as a glass forming apparatus for manufacturing an optical element, for example, a glass forming apparatus using a forming mold 90 in which a glass G is placed between a lower mold 91 and an upper mold 92 as shown in FIG. 7 is disclosed. (See Patent Document 1). In this glass forming apparatus, the forming mold 90 is conveyed by moving and stopping the mold conveying unit 96 while being heated from the lower side of the lower mold 91 and the upper side of the upper mold 92.

JP 2006-199537 A

  However, in the glass forming apparatus disclosed in Patent Document 1, cracks, segregation, and fogging are likely to occur in the formed glass molded body. In particular, when the glass molded body is used as an optical element as it is, it is required to improve the reproducibility of the dimensions of the glass molded body in order to surely impart desired optical performance to the optical element.

  The present invention has been made in view of the above circumstances, and manufacture of an optical element capable of improving the reproducibility of the dimensions of the optical element while reducing cracks, segregation, and fogging of the molded optical element. An object is to provide a method and a manufacturing apparatus.

  The present inventors adjust the temperature of the contact portion in contact with the molding die within a predetermined range among the conveying means for conveying the molding die, so that the contact portion of the molding die and the contact portion of the conveying means are in contact with each other. It has been found that the driving force of the conveying means is transmitted to the mold through the contact portion while the temperature difference is reduced, and the present invention has been completed.

  (1) A method of manufacturing an optical element by pressing glass, wherein a mold having an upper mold and a lower mold is sequentially moved and stopped with each of a heating stage, a pressing stage, and a cooling stage, The step of raising, pressing, and lowering the glass in the mold is performed, and the moving and stopping are performed at the contact portion where the temperature difference from the contacted portion of the mold is maintained within 20 ° C. The manufacturing method performed by moving the said contact part, contacting a type | mold.

  (2) The manufacturing method according to (1), wherein the contact portion is heated by being connected to each of the temperature raising stage, the pressing stage, and the temperature lowering stage so as to be able to conduct heat.

  (3) The manufacturing method according to (1) or (2), wherein the contact state between the contact portion and the mold is maintained during the movement and stop.

  (4) The manufacturing method according to (3), wherein a movable floor movable in the direction of movement is used as the contact portion, and the movement and stop are performed in a state where the molding die is placed on the movable floor.

  (5) The manufacturing method according to (1), wherein the contact portion is heated by a heating means different from the temperature raising stage, the pressing stage, and the temperature lowering stage.

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

  (7) A manufacturing apparatus for manufacturing an optical element by pressing glass, and a chamber having a temperature raising stage for raising a temperature of a mold having an upper mold and a lower mold, a pressing stage for pressing, and a temperature lowering stage for lowering the temperature. A conveying means for sequentially moving and stopping the molding die to the temperature raising stage, the pressing stage, and the temperature lowering stage, and the conveying means includes a contact portion that contacts the molding die, A drive unit that moves the contact unit, and the manufacturing apparatus detects the temperature of the contacted portion of the mold that is in contact with the contact unit, and the detection unit detects the temperature based on the detection result of the detection unit. And a temperature adjusting means for adjusting the temperature of the contact portion.

  (8) The manufacturing apparatus according to (7), wherein the contact portion is connected to each of the temperature raising stage, the pressing stage, and the temperature lowering stage so as to be able to conduct heat and thereby heated.

  (9) The manufacturing apparatus according to (7) or (8), wherein the contact portion maintains a contact state with the mold during the movement and stop.

  (10) The manufacturing apparatus according to (9), wherein the contact portion includes a movable floor on which the mold is placed and is movable in the moving direction.

  (11) The manufacturing apparatus according to (7), further comprising heating means that heats the contact portion and is different from the heating stage, the pressing stage, and the cooling stage.

  (12) An optical apparatus manufacturing system comprising: the manufacturing apparatus according to any one of (7) to (11); and a manufacturing apparatus that manufactures an optical apparatus from an optical element manufactured by the manufacturing apparatus.

  According to the present invention, the temperature difference between the contacted part and the contact part is adjusted by adjusting the temperature of the contact part that contacts the contacted part of the molding die within a predetermined range among the transporting means for transporting the mold. While being reduced, the driving force of the conveying means is transmitted to the mold through the contact portion. Therefore, local temperature fluctuations in the glass to be molded can be suppressed, and the inclination of the upper mold when the mold is pressed can be reduced. Therefore, the reproducibility of the dimensions of the optical element can be improved while reducing cracks, segregation and fogging of the molded optical element.

It is sectional drawing which shows a preferable example of the manufacturing method of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing to which the vicinity of the contact part of FIG. 1 was expanded. It is a top view which shows a preferable example of the manufacturing method of the optical element which concerns on 1st Embodiment of this invention. It is a top view which shows the modification of the manufacturing method of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing which shows a preferable example of the manufacturing method of the optical element which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows a preferable example of the manufacturing method of the optical element which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the transfer aspect of the shaping | molding die concerning a prior art.

  The optical element manufacturing method of the present invention is a manufacturing method in which an optical element is manufactured by pressing glass, and a mold having an upper mold and a lower mold is connected to each of a temperature raising stage, a pressing stage, and a temperature lowering stage. Steps of sequentially moving and stopping to raise, press, and lower the temperature of the glass in the mold, and the movement and stop of the mold within a temperature difference of 20 ° C. with respect to the contacted portion. It is performed by moving the contact portion while contacting the mold with the maintained contact portion.

  Further, the optical element manufacturing apparatus of the present invention is a manufacturing apparatus for manufacturing an optical element by pressing glass, a temperature rising stage for raising the temperature of a mold having an upper mold and a lower mold, a pressing stage for pressing, And a chamber having a temperature-decreasing stage for lowering the temperature, and conveying means for sequentially moving and stopping the molding die to each of the temperature-rising stage, the pressing stage, and the temperature-decreasing stage, and the conveying means includes the molding A contact unit that contacts the mold, and a drive unit that moves the contact unit, and the manufacturing apparatus detects a temperature of a contacted portion of the mold that is in contact with the contact unit, Temperature adjusting means for adjusting the temperature of the contact portion based on the detection result of the detecting means.

  Hereinafter, embodiments of the mold, the detachable toppling-suppressing structure, and the optical element manufacturing method of the present invention will be described in detail, but the present invention is not limited to the following embodiments at all. Within the range of the objective, it can implement by changing suitably. 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 detecting means 5 for detecting the temperature of the forming mold 2 and the temperature of the contact portion 43a of the conveying means 4a in the portion where the forming mold 2 and the conveying means 4a are in contact, and the forming mold 2 Temperature adjusting means (not shown) for adjusting the temperature of the contact portion 43a using the heat source 6 for heating the optical element manufacturing apparatus 1a. 1-3 is a figure which shows a preferable example of the manufacturing method of an optical element. FIG. 4 is a diagram showing a modification of the method for manufacturing an optical element.

[Optical element manufacturing equipment]
The optical element manufacturing apparatus 1a presses the glass G to manufacture the optical element L. Here, the optical element manufacturing apparatus appropriately selects from among apparatuses capable of performing the process of moving and stopping the mold 2 and the process of heating, pressing, and cooling the glass G in the mold 2. Selected. For example, the optical element manufacturing apparatus 1a shown in FIG. 1 includes a chamber 10, a transport unit 4a for sequentially moving and stopping the mold 2 inside the chamber 10, and a portion where the transport unit 4a and the mold 2 are in contact (FIG. 2). And a detecting means 5 for detecting the temperature of the contacted portion 24a and the contact portion 43a).

[Chamber]
The chamber 10 is configured so that the glass G housed in the mold 2 can be heated inside. A chamber 10 shown in FIGS. 1 and 3 includes a temperature raising stage 11 for heating a mold 2 having an upper mold 21 and a lower mold 23, a pressing stage 12 for pressing the mold 2, and a temperature lowering stage for lowering the mold 2. 13

  Here, the chamber 10 is preferably sealable by the shutter S when the mold 2 is not supplied and discharged. Thereby, since cooling of the shaping | molding die 2 by the flow of the external air of the chamber 10 is reduced, the fluctuation | variation of the local temperature of the shaping | molding die 2 can be reduced.

  The heat source 6 for heating the glass G accommodated in the chamber 10 is not particularly limited as long as it is a means capable of heating the mold 2 to the molding temperature of the glass G. For example, infrared heating, a gas burner, an induction coil, a heating wire or the like is used. be able to.

[Conveying means]
For example, as illustrated in FIG. 2, the transport unit 4 a includes a contact portion 43 a that contacts the contacted portion 24 a of the mold 2, a drive unit (not illustrated) that moves the contact unit 43 a, and a temperature that does not illustrate the contact unit 43 a Temperature adjusting means. As a result, the driving force of the drive unit is transmitted to the molding die 2 through the contact portion 43a while the temperature of the contact portion 43a is adjusted. Therefore, the temperature drop of the contacted portion 24a of the molding die 2 is reduced and the molding die is reduced. The mold 2 can be conveyed to a desired position while maintaining the temperature balance of 2.

  In the procedure of transporting the mold 2 in the chamber 10 using the transport means 4a, the mold 10 is sequentially moved and stopped from the outside of the chamber 10 to each of the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13, and thereafter The mold 2 is moved from the temperature lowering stage 13 to the outside of the chamber 10.

  Here, it is preferable that the conveying means 4a maintains the contact state with the mold 2 in the contact portion 43a during the movement and stop of the mold 2. Thereby, since the impact that occurs when the contact portion 43a and the mold 2 are separated and contacted again is avoided, the displacement of the position of the glass G relative to the mold 2 due to the impact when these contact can be reduced, As a result, the reproducibility of the shape of the optical element L can be further enhanced.

  Moreover, it is preferable to provide the conveyance means 4a so that the contact part 43a is connected to the heat source 6 provided in each of the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13 so as to be able to conduct heat. Thereby, since the contact part 43a is heated by the heat source 6, even if it does not provide a new heat source, the temperature of the shaping | molding die 2 can be adjusted via the contact part 43a. The means for heating the contact portion 43a is not limited to the above, and a heating means (heating means 48d) different from the heat source 6 may be provided as shown in FIG. Further, “connecting so as to be capable of conducting heat” may be a form of connection via the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13 as shown in FIG. 2, and other heat conductive members. It is also possible to use a configuration in which the heat source 6 and the contact portion 43a are in direct contact with each other.

  Here, as a specific aspect regarding the connection between the contact portion 43a of the transport unit 4a and the heat source 6, the heating surface 62 on which the molding die 2 is placed in the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13 is provided. An example in which the heat transfer part 42a adjacent to the contact part 43a is brought into contact with each other is given as an example. In particular, the heating surface 62 and the heat transfer part 42a may be brought into contact with each of the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13. Thereby, the contact part 43a heats the conveyance means 4a according to the temperature of each heating surface 62 of the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13. Therefore, it is possible to easily reduce the temperature difference between the contact portion 43a and the contacted portion 24a in each of a series of steps of heating, pressing, and cooling the mold 2.

  The shape of the conveying means 4a is appropriately selected from shapes that have thermal conductivity and can convey the mold 2. In particular, the shape of the contact portion 43a of the transport unit 4a is preferably a flat plate shape having a plane perpendicular to the transport direction T of the mold 2 as shown in FIGS. Thereby, the contact area of the contacted part 24a of the shaping | molding die 2 and the contact part 43a of the conveyance means 4a is reduced, and heat exchange does not occur easily between the contact part 43a and the contacted part 24a. Therefore, it is possible to quickly adjust the temperature of the contact portion 43a with limited heat from the heat source 6 while reducing the influence on the temperature balance in the horizontal direction of the mold 2.

  The material of the conveying means 4 a is appropriately selected from materials that can withstand the molding temperature of the glass G and can conduct the heat from the heat source 6 to the heating surface 62. In particular, the lower limit of the thermal conductivity of the material used for the contact part 43a and the heat transfer part 42a of the conveying means 4a is preferably 1.0 W / mK, more preferably 5.0 W / mK, and most preferably 10.0 W / m. mK. Thereby, since the temperature of the contact part 43c becomes easy to adjust, it is easy to maintain a temperature difference with the contacted part 24c, and the reproducibility of molding of the optical element L can be further enhanced. Examples of the material having both heat resistance and thermal conductivity include metals such as SUS and ceramics such as SiC.

  A driving unit (not shown) of the conveying unit 4a gives a driving force for moving the mold 2 to the contact unit 43a via the power transmission unit 41a. Thereby, since the shaping | molding die 2 is conveyed, the glass G accommodated in the shaping | molding die 2 can be shape | molded sequentially.

  For example, as shown in the optical element manufacturing apparatus 1b of FIG. 4, the conveying means 4b has a flat plate shape with an interval at which the mold 2 is accommodated in each of the front and rear with respect to the conveying direction T of the mold 2. The contact part 43b may be provided. Thereby, even if inertia force acts on the shaping | molding die 2 when driving and stopping a drive part, the contact state of a shaping | molding die and the contact part 43b continues. Therefore, the position shift of the glass G with respect to the mold 2 can be reduced while increasing the temperature balance in the mold 2.

[Detection means]
For example, as shown in FIG. 2, the detecting means 5 detects the temperature of the contacted portion 24a of the mold 2 and the temperature of the contact portion 43a of the conveying means 4a. Thereby, since it becomes clear whether the temperature of the to-be-contacted location 24a is a desired temperature with respect to the contact part 43a, the temperature of the to-be-contacted location 24a can be adjusted based on the detection result.

  The detecting means 5 is appropriately selected from temperature measuring means that can measure the temperature of the contacted portion 24a. Among these, it is preferable to use a temperature measuring means that does not come into contact with the contact portion 43a or the contacted portion 24a, such as a radiation thermometer. This makes it difficult for heat to be exchanged between the contact portion 43a or the contacted portion 24a and the detection means 5. Therefore, the temperature balance of the mold 2 can be maintained.

  The temperature measurement locations using the detection means 5 are preferably the contact location 24a and the contact portion 43a. Thereby, since the temperature of the to-be-contacted part 24a and the contact part 43a is measured directly, the exact temperature of the to-be-contacted part 24a and the contact part 43a can be detected, and the temperature difference of the contact part 43a and the to-be-contacted part 24a Can be easily adjusted accurately. Note that the temperature measurement location using the detection means 5 is not limited to the above-described location, but is a location in the vicinity of the contacted location 24a and the contact portion 43a, for example, a location where the height relative to the heating surface 62 of the mold 2 is substantially equal. May be. Thereby, even if the contact state of the contacted part 24a and the contact part 43a is maintained, the temperature is measured at a part where the heating state by the heating surface 62 is substantially equal to the contacted part 24a. For this reason, it is possible to increase the accuracy of the measured temperature while reducing the displacement of the position between the glass G and the mold 2.

[Temperature control means]
The temperature adjusting means (not shown) adjusts the temperature of the contact portion 43 a based on the detection result of the detecting means 5. Specifically, when the temperature of the contact portion 43a is lower than the temperature of the contacted portion 24a, the heat transfer portion 42a of the transport means 4a and the heating surface 62 are connected so as to be able to conduct heat using temperature adjusting means. Moreover, when the temperature of the contact part 43a is higher than the temperature of the to-be-contacted location 24a, the heat transfer part 42a and the heating surface 62 of the conveying means 4a are separated from each other using the temperature adjusting means. Thereby, the temperature of the contact part 43a increases when the heating surface 62 and the heat transfer part 42a are connected, and the temperature of the contact part 43a decreases when the heating surface 62 and the heat transfer part 42a are separated. . Therefore, the temperature of the contact portion 43a can be set within a predetermined range with respect to the temperature of the contacted portion 24a. Therefore, the molded optical element L can be made difficult to break, segregation and fogging of the optical element L can be reduced, and the reproducibility of the dimensions of the optical element L can be enhanced.

  The temperature adjusting means is not limited to means for connecting and / or separating the heating surface 62 and the heat transfer section 42a. For example, after using a material having higher thermal conductivity than the mold 2 as the conveying unit 4 a, the heating surface 62 and the heat transfer part 42 a are always connected so as to be able to conduct heat, and the output adjusting unit 61 is used. The output of the heat source 6 may be adjusted within a range that does not affect the press forming of the glass G. Thereby, when the output of the heat source 6 is adjusted, the temperature of the conveying means 4a is preferentially adjusted over the molding die 2, so that both the temperature adjusting means and the output adjusting means 61 can be used. The device 1a can have a simpler configuration.

[Mold]
The mold 2 conveyed by the conveying means 4a is appropriately selected from molds that can mold the glass G into the optical element L. For example, it has the upper mold | type 21 and the lower mold | type 23, and the molding surfaces 26 and 27 which shape | mold the glass G are provided in the upper surface of the lower mold | type 23, and the lower surface of the upper mold | type 21 so that it may oppose. Use what is provided. The materials of the upper mold 21 and the lower mold 23 are appropriately set according to the hardness of the glass G, the glass transition point (Tg), etc., but tungsten carbide (WC), etc., because it can withstand the pressure during press molding. It is preferable to use a cemented carbide member. A protective film (not shown) may be formed on each of the molding surfaces 26 and 27.

  The molding die 2 is preferably provided with a barrel die 22 so as to surround the upper die 21 and the lower die 23. Accordingly, the positional relationship in the horizontal direction between the lower mold 23 and the upper mold 21 is regulated while the inclination of the upper mold 21 with respect to the lower mold 23 is reduced, so that the dimensional reproducibility of the optical element L can be reduced. Can be increased.

  The means for supplying the glass G between the upper mold 21 and the lower mold 23 of the mold 2 and the means for taking out the optical element L from between the upper mold 21 and the lower mold 23 of the mold 2 are the size of the glass G Although it can select suitably according to the shape of the shaping | molding die 2, etc., the adsorption | suction means (not shown) which adsorb | sucks and hold | maintains the glass G and the optical element L with the attraction | suction force of a pump can be provided, for example. The means for assembling the upper mold 21 and the lower mold 23 into the mold 2 and the means for disassembling the mold 2 into the upper mold 21 and the lower mold 23 are not particularly limited. For example, a holding arm (not shown) is used. The upper die 21 can be placed on the lower die 23 while being held by the holding force.

<Optical element manufacturing method>
An optical element manufacturing method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3 with reference to the above-described optical element manufacturing apparatus 1a. In this optical element manufacturing method, the mold 2 is moved from the outside of the chamber 10 to the temperature raising stage 11 to raise the temperature of the glass G, and then the mold 2 is moved to the pressing stage 12 and the pressing means 7 is used. The glass G is pressed, then the mold 2 is moved to the temperature lowering stage 13 to lower the temperature of the glass G, and then the mold 2 is moved to the outside of the chamber 10.

  The movement and stop of the mold 2 keep the temperature difference between the contact part 43a and the contacted part 24a within 20 ° C. at the part where the contact part 43a of the conveying means 4a and the contacted part 24a of the mold 2 contact. However, it is performed by moving the contact portion 43a of the transport means 4a. Thereby, the mold 2 is moved while the temperature difference in the mold 2 and the glass G is reduced. Therefore, the mold 2 can be placed at a predetermined position in the chamber 10 while reducing the inclination of the upper mold when the mold 2 is pressed. Therefore, the reproducibility of the dimension of the optical element L can be improved while reducing cracks, segregation and fogging of the optical element L to be molded.

  Here, the detection of the temperature difference between the contact portion 43a and the contacted portion 24a is performed using a temperature measuring means capable of measuring these temperatures. Among these, it is preferable to use a temperature measuring means that does not come into contact with the contact portion 43a or the contacted portion 24a, such as a radiation thermometer. Thereby, since heat exchange is not performed between the contact portion 43a or the contacted portion 24a and the detection means 5, the temperature balance of the mold 2 can be maintained.

  Moreover, it is preferable to measure the temperature of the contact part 43a and the contacted part 24a directly with respect to the contacted part 24a and the contact part 43a. Thereby, since the exact temperature of the to-be-contacted location 24a and the contact part 43a is detected, it can be easy to adjust the temperature difference of the contact part 43a and the to-be-contacted location 24a within the predetermined range. In addition, the measurement of the temperature of the contact part 43a and the contacted part 24a is not limited to the above-mentioned form, You may perform with respect to the contacted part 24a and the vicinity of the contact part 43a. In this case, by using the temperature difference between the temperature of the contacted part 24a and / or the contact part 43a and the temperature of the measured part, the temperature of the measured part is adjusted to adjust the contacted part 24a and The temperature of the contact part 43a can be calculated | required.

  Here, the maximum value of the temperature difference between the contact portion 43a and the contacted portion 24a is preferably 20 ° C., more preferably 18 ° C., and most preferably 15 ° C. Thereby, heat exchange through the contact portion 43a and the contacted portion 24a is reduced, and the temperature difference inside the glass G is reduced. Therefore, the local fluctuation | variation regarding the viscosity of the glass G when it softens with the press stage 12 can be reduced. Therefore, cracks, segregation and fogging of the optical element L to be molded can be further reduced.

  For example, as shown in FIG. 2, the temperature of the contact portion 43 a is adjusted by connecting the contact portion 43 a and the heat source 6 of the temperature raising stage 11, the pressing stage 12, and / or the temperature lowering stage 13 so as to conduct heat. To do. Thereby, when the contact part 43a and the heat source 6 are connected, the contact part 43a is heated via the heat-transfer part 42a. Moreover, when the contact part 43a and the heat source 6 are separated, the temperature is lowered by allowing the contact part 43a to cool. Therefore, the temperature difference between the contact portion 43a and the contacted portion 24a can be kept within a predetermined range. In particular, when the heating means of the contact part 43a and the heat source 6 are provided separately, the temperature of the contact part 43a need not be adjusted by the heat source 6.

  The contact portion 43 a preferably maintains the contact state with the mold 2 while sequentially moving and stopping the mold 2 inside the chamber 10. Thereby, after the contact part 43a and the shaping | molding die 2 leave | separated, the impact which arises when these are made to contact again is avoided. Therefore, while maintaining the heat balance in the horizontal direction of the mold 2, the influence on the molding of the glass G due to the impact when the mold 2 is conveyed can be reduced.

[Production of optical equipment]
An optical element L such as a lens or a prism is manufactured by the above-described optical element manufacturing apparatus 1a. Also, an optical device manufacturing system including an optical device manufacturing apparatus 1a and an optical device manufacturing apparatus (not shown) that manufactures an optical device such as a camera or a projector from the optical element L is constructed to manufacture the optical device. Is also preferable. Thereby, since the glass G is press-molded with higher accuracy and the life of the molding die 2 is extended, the manufacturing costs of the optical element L and the optical apparatus can be reduced.

Second Embodiment
2nd Embodiment of this invention is an optical element manufacturing method using the optical element manufacturing apparatus 1c provided with the movable floors 44c-46c which can mount the shaping | molding die 2 as the contact part 43c of the conveyance means 4c. FIG. 5 is a diagram illustrating a preferred example of an optical element manufacturing apparatus 1c used in the method for manufacturing an optical element.

[Conveying means]
For example, as illustrated in FIG. 5, the transport unit 4 c includes a contact portion 43 c that includes a heating surface 62 on which the mold 2 is placed and has movable floors 44 c to 46 c that are movable in the transport direction T of the mold 2. The driving unit 47c moves and stops the contact unit 43c in the transport direction T, and the temperature adjusting unit 49c adjusts the temperature of the contact unit 43c. Thereby, the shaping | molding die 2 is conveyed, contacting the contact part 43c provided with the heating surface 62, and the to-be-contacted location 24c of the shaping | molding die 2 so that heat conduction is possible. Therefore, while reducing the impact due to separation and contact between the contact portion 43c and the mold 2 when the mold 2 is conveyed, the temperature of the entire mold 2 as well as the vicinity of the contacted portion 24c is reduced. Can be adjusted via. Therefore, it is possible to increase the temperature balance in the horizontal direction of the mold 2 (a method parallel to the heating surface 62) while reducing the displacement of the position of the glass G with respect to the mold 2. In addition, the contact part 43c is not limited to what consists of movable floors 44c-46c, A part of contact part 43c provided about the temperature rising stage 11, the press stage 12, and the temperature decreasing stage 13 may not be movable. .

  A specific mode of the transport unit 4c is appropriately selected from modes in which the mold 2 can be placed and transported. In particular, as shown in FIG. 5, the contact portion 43 c includes a first movable floor 44 c provided for the temperature raising stage 11, a second movable floor 45 c provided for the pressing stage 12, and a third movable floor provided for the temperature lowering stage 13. 46c, which are preferably separate from each other. Thereby, the mold 2 is set while the temperatures of the first movable floor 44c, the second movable floor 45c, and the third movable floor 46c are set to temperatures suitable for the temperature raising stage 11, the pressing stage 12, and the temperature lowering stage 13, respectively. Are sequentially conveyed to the first movable floor 44c, the second movable floor 45c, and the third movable floor 46c. Therefore, by changing the movable floors 44c to 46c to which the molding die 2 is conveyed while increasing the temperature balance in the horizontal direction of the molding die 2, the temperature change of the molding die 2 when the molding die 2 is moved is quickly changed. Can be done.

  As the material and shape of the movable floors 44c to 46c of the conveying means 4c, it is preferable to use a material and shape having heat resistance and heat conductivity and elastic deformation. More specifically, for example, a molded product formed into a film or sheet shape made of a material having a low Young's modulus and a high yield stress (metal such as SUS) can be used. As a result, the movable floors 44c to 46c are elastically deformed according to the shape of the conveying means 4c, so that a flat heating surface 62 is formed. Therefore, the adhesion between the heating surface 62 and the contacted portion 24c of the mold 2 can be increased, and as a result, the temperature balance in the horizontal direction of the mold 2 can be further increased. The movable floors 44c to 46c are not limited to the above-described form. For example, a plurality of materials (such as ceramics such as SiC) that have a high Young's modulus and are difficult to elastically deform are formed into a plate shape or a rod shape so that they can move relative to each other. The movable floors 44c to 46c may be formed adjacent to each other.

[Temperature control means]
The temperature adjusting means 49c of the conveying means 4c uses the output adjusting means 61 of the heat source 6. Here, the output adjusting means 61 adjusts the output of the heat source 6 within a range that does not affect the press forming of the glass G.

<Third Embodiment>
In the third embodiment of the present invention, the detecting means 5 for detecting the temperature of the contact portion 43d between the mold 2 and its conveying means 4d and the heating means 48d provided independently of the heat source 6 for heating the mold 2 are provided. And a temperature adjusting means 49d for adjusting the temperature of the contact portion 43d using the optical element manufacturing apparatus 1d. FIG. 6 is a diagram illustrating a preferred example of a method for manufacturing an optical element.

[Temperature control means]
The temperature adjusting means 49d adjusts the output of the heating means 48d that heats the contact portion 43d. Here, the heating means 48d is provided independently of the heat source 6 for heating the mold 2. As a result, the temperature independent of the heating surface 62 for heating the mold 2 can be controlled, so that the temperature difference between the contact portion 43d and the mold 2 can be further reduced, and the horizontal direction of the mold 2 can be reduced. The temperature balance can be further increased.

  At this time, as shown in FIG. 6, the conveying means 4d and the heating surface 62 may be always separated from each other, but they may be brought into contact as necessary. In particular, by always separating the conveying means 4d and the heating surface 62, the magnitude of the output of the heating means 48d adjusted by the temperature adjusting means 49d is directly reflected in the temperature of the contact part 43d. The temperature control mechanism of 43d can be simplified. On the other hand, since the contact part 43d is heated by both the heating means 48d and the heating surface 62 by bringing the contact part 43d and the heating surface 62 into contact as necessary, the temperature of the contact part 43d is increased. The amount of heat required can be reduced.

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

  The optical element manufacturing apparatus comprises a heat source for raising the temperature of the raw material glass from the lower side of the mold with an induction coil, and a pressing means for pressing the raw material glass. , And a temperature lowering stage were sequentially provided. At this time, the chamber of the optical element manufacturing apparatus can be shut off and opened as necessary with a shutter to facilitate the insertion and removal of the mold.

Here, in the optical element manufacturing apparatus, a member having the shape shown in FIG. 2 was used as the conveying means. That is, as a conveying means, a heat transfer section consisting of a plane provided in parallel with a heating surface for raising the temperature of the mold in the optical element manufacturing apparatus, and a direction perpendicular to the heating surface and the conveying direction of the mold A member made of SUS (thermal conductivity: about 15 to 20 W / mK) having a contact portion made of a plane provided vertically was used. Here, the area of the temperature adjusting means was 25 mm ² .

  As the molds for press molding, an upper mold and a lower mold each having a diameter of 15 mm and a height of 10 mm and made of WC were used. The upper mold and the lower mold were each provided with a molding surface composed of a spherical surface having a diameter of 20 mm and a depth of 2 mm so as to face each other. Then, a cylindrical body having a right cylindrical shape having an outer diameter of 21 mm, an inner diameter of 15 mm, and a height of 21 mm was provided so as to be adjacent to and surround the upper mold and the lower mold.

  Here, the mold is supplied to a predetermined position of the optical element manufacturing apparatus, the upper mold is lifted using a holder, and the raw glass (glass transition point: 566 ° C.) is supplied to the lower mold of the mold. Was placed on the lower mold, and the upper mold and the lower mold were assembled into a mold.

  The assembled mold was supplied into the chamber of the optical element manufacturing apparatus. The mold supplied to the optical element manufacturing apparatus drives the driving means of the conveying means, and sequentially moves and stops the temperature raising stage, the pressing stage, and the temperature lowering stage. Of these, in the temperature raising stage, the temperature of the part at the height position where the glass was placed in the mold was raised to a press molding temperature of 620 ° C., and the raw glass was softened. Then, when the molding die moved to a predetermined position of the pressing stage, the movement of the molding die was stopped, the upper die was lowered using the pressing means, the glass was pressed, and the glass was press-molded. After press molding, the pressing means was separated from the mold, the mold was further moved, and the mold was gradually cooled while being moved on the temperature lowering stage sequentially. The molding die cooled at the temperature lowering stage moved to the outside of the chamber using the conveying means.

  The contact portion of the conveying means is brought into contact with the side surface of the mold from when the mold is supplied to the inside of the chamber until it is moved to the outside of the chamber. Further, a radiation thermometer (model number: IR-AhS, manufactured by Chino Co., Ltd.) is used as the detection means, and the temperature of the contacted portion of the mold and the temperature of the contact portion of the conveying means while the mold is inside the chamber. Was measured. Based on the measurement results, when the temperature of the contact portion is 20 ° C. or more lower than the temperature of the contacted portion, the temperature adjusting means is brought into contact with the heating surface. Moreover, when the temperature of the contact portion was 20 ° C. or more higher than the temperature of the contacted portion, the heat transfer portion of the conveying means was separated from the heating surface.

  The molding die lowered in temperature at the temperature lowering stage was moved to the outside of the chamber using the conveying means, and was disassembled into an upper die and a lower die, and the optical element was taken out. About the obtained optical element, while using a 100 times optical microscope (model number: LV-150, Nikon Co., Ltd.), the state of cracking, segregation and cloudiness of the optical element is confirmed, and the thickness distribution of the optical element Was measured with a Digimatic caliper (model number: CD-15CSX, manufactured by Mitutoyo Corporation).

  As a comparative example, the same test as in the example was performed even when the conveying unit was lifted from the heating surface of the temperature raising stage, the pressing stage, and the temperature lowering stage and the temperature of the contact portion of the conveying unit was not increased. Moreover, the test similar to an Example was done also about the case where the temperature of a contact part is maintained in the state 25-25 degreeC lower than the temperature of a to-be-contacted location.

  As a result, when the contact part of the conveying means of the optical element manufacturing apparatus is not heated, the formed optical element is cracked, segregated or clouded, and the shape of the optical element does not become a predetermined shape. (Formation defective product) occurred at a rate of about 5%, but when the contact part of the conveying means of the optical element manufacturing apparatus was heated, the optical element was cracked, segregated or clouded, and optical The defective molding of the element was reduced to about 1%. On the other hand, when the temperature of the contact portion is maintained at a temperature lower by 25 ° C. to 30 ° C. than the temperature of the contacted portion, the optical element is cracked, segregated, or cloudy, and the optical element has a molding defect of about 5 %Met. Comparing optical elements produced in Examples and Comparative Examples, by heating the contact portion of the conveying means, it is difficult to cause cracking, segregation and fogging in the optical element, and an optical element with improved dimensional reproducibility is obtained. It can be seen that it can be formed with higher probability.

G Glass L Optical element T Transport direction 1a to 1d Optical element manufacturing apparatus 10 Chamber 11 Temperature rising stage 12 Pressing stage 13 Temperature decreasing stage 2 Mold 21 Upper mold 22 Body mold 23 Lower mold 24a to 24d Contacted portions 26 and 27 Molding surface 4a-4d Conveying means 41a, 41b, 41d Power transmission means 42a-42d Heat transfer parts 43a-43d Contact part 44c First contact part 45c Second contact part 46c Third contact part 47c Driving part 48d Heating means 49c, 49d Temperature Adjustment means 5 Detection means 6 Heat source
61 Output adjustment means 62 Heating surface 7 Press means

Claims (12)

A manufacturing method for manufacturing an optical element by pressing glass,
A step of sequentially moving and stopping the mold having the upper mold and the lower mold with each of the temperature raising stage, the pressing stage, and the temperature lowering stage to raise, press and lower the temperature of the glass in the mold; ,
The said movement and a stop are the manufacturing methods performed by moving the said contact part, contacting the said shaping | molding die in the contact part which maintained the temperature difference with a to-be-contacted place within 20 degreeC among the said shaping | molding die.   The manufacturing method of Claim 1 which heats the said contact part by connecting with each of the said temperature rising stage, the said press stage, and the said temperature fall stage so that heat conduction is possible.   The manufacturing method of Claim 1 or 2 with which the contact state of the said contact part and the said shaping | molding die is maintained during the said movement and a stop.   The manufacturing method according to claim 3, wherein a movable floor movable in the direction of movement is used as the contact portion, and the movement and stop are performed in a state where the mold is placed on the movable floor.   The manufacturing method according to claim 1, wherein the contact portion is heated by a heating means different from the temperature raising stage, the pressing stage, and the temperature lowering stage.   The manufacturing method of the optical instrument using the optical element manufactured with the manufacturing method in any one of Claim 1 to 5. A manufacturing apparatus for manufacturing an optical element by pressing glass,
A temperature raising stage for raising the temperature of a mold having an upper mold and a lower mold, a pressing stage for pressing, and a chamber having a temperature lowering stage for lowering temperature;
Conveying means for sequentially moving and stopping the molding die to each of the temperature raising stage, the pressing stage, and the temperature lowering stage, and
The transport means has a contact portion that contacts the mold, and a drive unit that moves the contact portion,
The manufacturing apparatus includes a detection unit that detects a temperature of a contacted portion of the mold that is in contact with the contact unit, a temperature adjustment unit that adjusts the temperature of the contact unit based on a detection result of the detection unit, A manufacturing apparatus further comprising:   The manufacturing apparatus according to claim 7, wherein the contact portion is connected to each of the temperature raising stage, the pressing stage, and the temperature lowering stage so as to be able to conduct heat and thereby heated.   The manufacturing apparatus according to claim 7, wherein the contact portion maintains a contact state with the mold during the movement and stop.   The manufacturing apparatus according to claim 9, wherein the contact portion includes a movable floor on which the mold is placed and movable in the direction of movement.   The manufacturing apparatus according to claim 7, further comprising heating means for heating the contact portion and different from the temperature raising stage, the pressing stage, and the temperature lowering stage.   An optical apparatus manufacturing system comprising: the manufacturing apparatus according to claim 7; and a manufacturing apparatus that manufactures an optical apparatus from an optical element manufactured by the manufacturing apparatus.

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