JP2012180252A - Method for producing optical element, mold set for molding the optical element, and apparatus for producing the optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an optical element capable of suppressing generation of clouding and decentering on the optical element, and to provide a mold set for molding the optical element, and an apparatus for producing the optical element.SOLUTION: This method for producing an optical element has: a centering process for arranging an upper die 2g, a lower die 11 and an optical material 100 so that the center axis A1 of a molding surface 2g-1 of the upper die 2g, the center axis A2 of a molding surface of the lower die 11, and the center A3 of the optical material 100 agree with each other; a heating process for heating the optical material 100 in the noncontact state with the molding surface 2g-1 of the upper die 2g and the molding surface of the lower die 11; a contact process for moving the upper die 2g close to the heated optical material 100 to bring the molding surface 2g-1 of the upper die 2g into contact therewith; a pressurizing process for pressurizing the optical material 100 in the contact state with the molding surface 2g-1 of the upper die 2g by moving the lower die 11 close to the upper die 2g; and a cooling process for cooling the pressurized optical element 100.

Description

  The present invention relates to an optical element manufacturing method and an optical element manufacturing apparatus for manufacturing an optical element by heating, pressing and cooling an optical material, and an optical element molding die set used for manufacturing the optical element. About.

  Conventionally, the technique of Patent Document 1 is known as a technique for positioning an optical material, which is a thermoplastic material, at the center of a mold and molding a concave surface portion of a meniscus lens or plano-concave lens as an optical element and a subsequent flat surface portion. It has been.

Hereinafter, the optical element molding die set according to the first reference technique (for example, see FIG. 2 of Patent Document 1) and the second reference technique (for example, see FIG. 6A of Patent Document 1) will be briefly described.
FIG. 11 is a cross-sectional view showing an optical element molding die set 50 according to the first reference technique.

  A mold set 50 shown in FIG. 11 includes an upper mold 51 and a lower mold 52 that are arranged to face each other, a cylindrical sleeve 53 that aligns the optical axes of the upper mold 51 and the lower mold 52, and a ball within the sleeve 53. And a cylindrical holding member 54 that holds the optical material 100 having a shape.

  The optical material 100 is positioned at the center by the holding member 54, and is heated and softened in a non-contact state with the molding surface 51 a of the upper mold 51 and the molding surface 52 a of the lower mold 52. Thereafter, the optical material 100 is pressurized as the lower mold 52 rises and penetrates the holding member 54. And the optical element is obtained because the pressurized optical material 100 is cooled.

FIG. 12 is a cross-sectional view showing an optical element molding die set 60 according to the second reference technique.
A mold set 60 shown in FIG. 12 includes an upper mold 61 and a lower mold 62 that are arranged to face each other, a cylindrical sleeve 63 that aligns the optical axes of the upper mold 61 and the lower mold 62, and a ball within the sleeve 63. And a cylindrical holding member 64 that holds the optical material 100 having a shape.

  In the mold set 60 shown in FIG. 12, the optical material 100 is positioned at the center while being sandwiched between the upper mold 61 and the holding member 64. Thereafter, the optical material 100 is heated and softened, and the lower mold 62 is raised and pressed through the holding member 64. And the optical element is obtained because the pressurized optical material 100 is cooled.

JP 2009-227532 A

  By the way, in the mold set 50 shown in FIG. 11, the spherical optical material 100 is heated and softened without contact with the molding surfaces 51a and 52a of the upper mold 51 and the lower mold 52. When the optical material 100 is pressed, the spherical optical material 100 may be displaced from the center. If the optical material 100 is pressed by the lower mold 52 as it is, the optical element may be decentered.

  In the mold set 60 shown in FIG. 12, the molding surface 61 a of the upper mold 61 and the optical material 100 are in contact with each other before heating, so that the optical material 100 is heated in a state of being in partial contact with the molding surface 61 a of the upper mold 61. As a result, a spider may be generated in the optical element at the part in contact with the part.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical element manufacturing method, an optical element molding die set, and an optical element manufacturing apparatus that can suppress the occurrence of clouding and eccentricity in an optical element.

  In the optical element manufacturing method of the present invention, the upper mold, the lower mold, and the optical material are arranged so that the center axis of the molding surface of the upper mold, the center axis of the molding surface of the lower mold, and the center of the optical material are aligned. A centering step, a heating step of heating the optical material in a non-contact state with the molding surface of the upper die and the molding surface of the lower die, and moving the upper die closer to the heated optical material. The contact step of bringing the molding surface of the upper mold into contact with each other, and pressurizing the optical material in contact with the molding surface of the upper mold by moving the lower mold closer to the upper mold And a cooling step for cooling the pressurized optical material.

In the method for manufacturing the optical element, in the contact step, the position regulating member that regulates the position of the upper mold is pulled out so that the molding surface of the upper mold is not in contact with the optical material, and the upper It is advisable to release the restriction on the position of the mold.
Further, in the optical element manufacturing method, before the contacting step, the upper mold is lifted by the upper mold lifting portion so that the molding surface of the upper mold is not in contact with the optical material. Good.

  The optical element molding die set according to the present invention includes a sleeve that aligns the central axis of the molding surface of the upper mold and the central axis of the molding surface of the lower mold by regulating the positions of the outer peripheral portions of the upper mold and the lower mold. And the center of the optical material in a non-contact state with the molding surface of the upper mold and the molding surface of the lower mold is the center axis of the molding surface of the upper mold and the molding surface of the lower mold. A holding member that holds the optical material so as to coincide with the central axis, and a position restriction member that restricts the position of the upper die so that the molding surface of the upper die is not in contact with the optical material; A mold set for molding an optical element.

In the optical element molding die set, the position restricting member may be disposed between the upper die and the upper end of the sleeve.
In the optical element molding die set, a gap in the height direction between the upper die and the upper end of the sleeve increases from the inner peripheral side to the outer peripheral side of the sleeve, and the height of the position restricting member increases. The thickness in the direction may be increased from the inner peripheral side to the outer peripheral side of the sleeve. Also, in the optical element molding die set, the position regulating member may be configured such that the position restricting member moves the sleeve from the outer peripheral side to the inner peripheral side. It is preferable to support the lower end of the upper mold.

  The first optical element manufacturing apparatus according to the present invention includes a plurality of stages to which the optical element molding mold set is sequentially transferred, and at least one of the plurality of stages, and the optical element molding mold set. A heating unit that heats the optical material accommodated in the optical element, a pressurizing unit that is disposed on at least one of the plurality of stages and pressurizes the optical material accommodated in the optical element molding die set, and the optical A drawing portion for drawing out the position regulating member of the element molding die set from a position for regulating the position of the upper mold;

  The second optical element manufacturing apparatus of the present invention includes a plurality of stages to which an optical element molding die set having an upper mold arranged to face a lower mold is sequentially transferred, and at least one of the plurality of stages. The heating unit that heats the optical material housed in the optical element molding die set and the at least one of the plurality of stages, and the housing housed in the optical element molding die set A pressurizing unit configured to pressurize the optical material; and an upper mold lifting unit configured to lift the upper mold so that a molding surface of the upper mold is not in contact with the optical material.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a spider and eccentricity arise in an optical element.

It is sectional drawing which shows schematic structure of the manufacturing apparatus of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the optical element shaping | molding die set which concerns on 1st Embodiment of this invention. It is sectional drawing (the 1) of the heating and pressurization stage for demonstrating the manufacturing method of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing (the 2) of the heating and pressurization stage for demonstrating the manufacturing method of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing (the 3) of the heating and pressurization stage for demonstrating the manufacturing method of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the optical element shaping type | mold set concerning 2nd Embodiment of this invention. It is a top view which shows the optical element shaping type | mold set concerning 2nd Embodiment of this invention. It is sectional drawing (the 1) of the heating and pressurization stage for demonstrating the manufacturing method of the optical element which concerns on 2nd Embodiment of this invention. It is sectional drawing (the 2) of the heating and pressurization stage for demonstrating the manufacturing method of the optical element which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the optical element shaping type | mold set which concerns on the 1st modification of 2nd Embodiment of this invention. It is sectional drawing which shows the optical element shaping type | mold set which concerns on the 2nd modification of 2nd Embodiment of this invention. It is sectional drawing which shows the optical element shaping type | mold set concerning 3rd Embodiment of this invention. It is sectional drawing of the heating and pressurization stage for demonstrating the manufacturing method of the optical element which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the optical element shaping type | mold set concerning a 1st reference technique. It is sectional drawing which shows the optical element shaping type | mold set concerning a 2nd reference technique.

  Hereinafter, an optical element manufacturing method, an optical element molding die set, and an optical element manufacturing apparatus according to embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a cross-sectional view showing a schematic configuration of an optical element manufacturing apparatus 1 according to the first embodiment of the present invention.
FIG. 2 is a sectional view showing the optical element molding die set 10 according to the first embodiment of the present invention.

  The optical element manufacturing apparatus 1 shown in FIG. 1 includes a heating / pressurizing stage 2, a cooling stage 3, and a molding chamber 4. The optical element manufacturing apparatus 1 is a circulation type manufacturing apparatus that manufactures an optical element, for example, a glass lens, by sequentially transferring an optical element molding die set 10 to a heating / pressurizing stage 2 and a cooling stage 3. .

  The heating / pressure stage 2 includes an upper heating plate (upper heat transfer member) 2a, a lower heating plate (lower heat transfer member) 2b, an upper cartridge heater (heating unit) 2c, and a lower cartridge heater (heating unit) 2d. And an air cylinder 2e, a base 2f, an upper mold 2g, and a protruding member (pressurizing part) 2h.

  The cooling stage 3 includes an upper heating plate (upper heat transfer member) 3a, a lower heating plate (lower heat transfer member) 3b, an upper cartridge heater (cooling unit) 3c, a lower cartridge heater (cooling unit) 3d, an air A cylinder 3e and a base 3f are included.

  Two upper cartridge heaters 2c and 3c are built in the upper heating plates 2a and 3a, respectively. An upper mold 2 g is fixed to the upper heating plate 2 a of the heating / pressurizing stage 2. The upper heating plate 2 a and the upper mold 2 g of the heating / pressurizing stage 2 are not in direct contact with the optical material 100, but the upper cartridge heater 2 c is used to heat the optical material 100.

The upper heating plate 3 a of the cooling stage 3 abuts on the upper end of the sleeve 12 of the optical element molding die set 10. The upper cartridge heater 3c heats the upper heating plate 3a at a cooling temperature. Thereby, the upper heating plate 3 a can cool the optical material 100.
The lower heating plates 2b and 3b are disposed on the bases 2f and 3f. An optical element molding die set 10 is placed on the lower heating plates 2b and 3b.

  Two lower cartridge heaters 2d and 3d are built in the lower heating plates 2b and 3b, respectively. The lower cartridge heater 2 d of the heating / pressurizing stage 2 is used to heat the optical material 100. The lower cartridge heater 3d of the cooling stage 3 heats the lower heating plate 3b at a cooling temperature.

  The air cylinders 2e and 3e drive the upper heating plates 2a and 3a in the vertical direction. The air cylinder 2e of the heating / pressurizing stage 2 is brought into contact with the optical material 100 by lowering the upper mold 2g fixed to the upper heating plate 2a.

The upper mold 2g of the heating / pressurizing stage 2 has a molding surface 2g-1 formed at the lower end and a flange portion 2g-2 formed at the upper end.
The projecting member 2h of the heating / pressurizing stage 2 passes through the base 2f and the through holes 2f-1 and 2b-1 of the lower heating plate 2b, and presses the lower end center of the lower mold 11 upward, thereby producing an optical material. 100 is pressurized.

  The heating / pressurizing stage 2 and the cooling stage 3 are disposed in the molding chamber 4 except for the air cylinders 2e and 3e. The molding chamber 4 is filled with an inert gas such as nitrogen.

As shown in FIG. 2, the optical element molding die set 10 includes a lower die 11, a sleeve 12, and a holding member 13.
The lower mold 11 is provided with a cylindrical small-diameter portion 11b having a smaller diameter than the large-diameter portion 11a and projecting upward from the large-diameter portion 11a at the upper center of the cylindrical large-diameter portion 11a as a base. A convex molding surface 11c for transferring the concave shape to the optical material 100 is formed at the upper end of the small diameter portion 11b.

  The sleeve 12 has a cylindrical shape. The sleeve 12 has a constant outer diameter, but the lower part is a thick part 12a and the upper part is a thin part 12b. Therefore, a step portion 12c is formed on the inner peripheral surface between the thick portion 12a and the thin portion 12b. The holding member 13 is placed on the stepped portion 12c at the flange portion 13a. In the thick part 12a of the sleeve 12, a lower mold 11 is slidably inserted in the large diameter part 11a. The sleeve 12 aligns the central axis A1 of the molding surface 2g-1 of the upper mold 2g and the central axis A2 of the molding surface 11c of the lower mold 11 by regulating the positions of the outer peripheral portions of the upper mold 2g and the lower mold 11. .

  The holding member 13 has a cylindrical shape with a flange portion 13a formed at the lower end. A small diameter portion 11b of the lower mold 11 is slidably inserted into the holding member 13 from below. The optical material 100 is placed at the center of the upper end of the holding member 13. Thus, the spherical optical material 100 is placed at the center of the upper end of the holding member 13 so that the center A3 of the optical material 100 coincides with the central axis A2 of the molding surface 11c of the lower mold 11.

The upper mold 2g of the heating / pressurizing stage 2 descends and is inserted into the sleeve 12, and comes into contact with the upper end of the sleeve 12 at the flange portion 2g-2.
The optical element molding die set 10 includes the lower die 11, the sleeve 12, and the holding member 13. However, it is sufficient that the optical element molding die set 10 includes at least the sleeve 12 and the holding member 13, for example, not only the upper die 2g. The lower mold 11 may also be fixed to the heating / pressure stage 2.

Hereinafter, the manufacturing method of the optical element according to the present embodiment will be described.
3A to 3C are cross-sectional views of the heating / pressurizing stage 2 for explaining the method of manufacturing the optical element according to the first embodiment of the present invention.

  First, the optical material 100 is placed at the center of the upper end of the holding member 13 of the optical element molding die set 10 so that the center A3 of the optical material 100 coincides with the central axis A2 of the molding surface 11c of the lower mold 11. . Then, the optical element molding die set 10 is carried into the molding chamber 4 shown in FIG. 1, and is placed at the center of the lower heating plate 2b of the heating / pressurizing stage 2 as shown in FIG. 3A. At this time, the upper mold 2g and the lower mold 11 are arranged such that the central axis A2 of the molding surface 11c of the lower mold 11 and the center A3 of the optical material 100 coincide with the central axis A1 of the molding surface 2g-1 of the upper mold 2g. And the optical material 100 are arranged (centering step).

  Then, the optical material 100 in a non-contact state with the molding surface 2g-1 of the upper mold 2g and the molding surface 11c of the lower mold 11 is heated to a temperature equal to or higher than the glass yield point by the upper cartridge heater 2c and the lower cartridge heater 2d. (Heating step). When the optical material 100 is heated, the upper die 2g may be inserted into the sleeve 12 in a range where the molding surface 2g-1 of the upper die 2g does not contact the optical material 100.

  Next, as shown in FIG. 3B, the air cylinder 2e lowers the upper heating plate 2a, and the upper die 2g fixed to the upper heating plate 2a is moved closer to the heated optical material 100, whereby the upper die The molding surface 2g-1 of 2g contacts the optical material 100 (contact process). In this contact step, the upper mold 2g may slightly pressurize the optical material 100. However, as will be described later, the optical material 100 is pressed by pressing the lower mold 11 or the lower mold 11 and the upper mold 2g. It is mainly performed in the pressurization process by both pressing.

  As shown in FIG. 3C, in a state where the molding surface 2g-1 of the upper mold 2g is in contact with the optical material 100, the protruding member 2h presses the lower mold 11 upward to move closer to the upper mold 2g. The optical material 100 in contact with the molding surface 2g-1 of the mold 2g is pressurized (pressure process). At this time, the upper die 2g may be moved closer to the lower die 11 by the air cylinder 2e.

  After the optical material 100 is pressurized to a desired thickness, the optical material 100 is cooled to a temperature near the glass transition point by the upper cartridge heater 2c and the lower cartridge heater 2d, for example.

  Thereafter, the protruding member 2h is lowered from the upper surface of the lower heating plate 2b to the lower side. Thereafter, the optical element molding die set 10 is transferred to the cooling stage 3 shown in FIG. Then, the optical material 100 is cooled by being cooled at the cooling temperature by the upper heating plate 3a and the lower heating plate 3b of the cooling stage 3 or by being naturally cooled (cooling step).

  Then, the optical element molding die set 10 is carried out of the molding chamber 4, and the manufactured optical element is taken out from the optical element molding die set 10.

  In the present embodiment described above, the center axis A1 of the molding surface 2g-1 of the upper mold 2g, the center axis A2 of the molding surface 11c of the lower mold 11 and the center A3 of the optical material 100 coincide with each other in the centering step. To. After the optical material 100 is heated in a non-contact state with the molding surface 2g-1 of the upper mold 2g and the molding surface 11c of the lower mold 11 (heating process), the optical material 100 comes into contact with the molding surface 2g-1 of the upper mold 2g. (Contact process), pressurized by the lower mold 11 (pressurization process).

  Therefore, the optical material 100 is heated in a non-contact manner with the molding surfaces 2g-1 and 11c of the upper die 2g and the lower die 11, so that the optical material 100 and the molding surfaces 2g-1 and 11c are in partial contact during heating. As a result, it is possible to suppress generation of spiders in the optical element. Further, by pressing the optical material 100 in contact with the molding surface 2g-1 of the upper mold 2g, it is possible to prevent the center A3 of the spherical optical material 100 from shifting and to cause eccentricity of the optical element. Can be prevented.

  Therefore, according to the present embodiment, it is possible to suppress the occurrence of spider and eccentricity in the optical element.

  In this embodiment, the example in which the heating unit (upper cartridge heater 2c and lower cartridge heater 2d) and the pressurizing unit (protruding member 2h) are arranged on the same stage (heating / pressurizing stage 2) has been described. The pressurizing unit and the cooling unit may be arranged on the same stage. Further, the heating unit, the pressure unit, and the cooling unit may be arranged on the same stage. In addition, each of the heating unit, the pressurizing unit, and the cooling unit may be independently arranged on one or more stages.

Second Embodiment
4 and 5 are a sectional view and a plan view showing an optical element molding die set 20 according to the second embodiment of the present invention. 6A and 6B are cross-sectional views of the heating / pressurizing stage 2-1 for explaining the method of manufacturing an optical element according to the second embodiment of the present invention.

  In the optical element molding die set 20 according to the present embodiment, the lower die 11, the sleeve 12, and the holding member 13 are the same as those of the optical element molding die set 10 according to the first embodiment, and the upper die 21 and the position. The restriction member 22 is different.

  In this embodiment, the upper die 21 is not fixed to the upper heating plate 2a of the heating / pressurizing stage 2-1 shown in FIGS. 6A and 6B, but as a part of the optical element molding die set 20. Has been placed. The upper die 21 has a molding surface 21a at the lower end and a flange portion 21b at the upper end.

  The position restricting member 22 has, for example, a plate shape extending in a horizontal plane, and is disposed between the upper die 21 and the upper end of the sleeve 12, for example, two on the left and right, so that the molding surface 21 a of the upper die 21 is formed on the optical material 100. The position of the upper mold 21 is regulated so as to be in a non-contact state.

  As shown in FIG. 5, the two position regulating members 22 are arranged so as to face each other, and, for example, have a trapezoidal shape whose width becomes narrower toward the inner peripheral side of the sleeve 12 in plan view.

  Hereinafter, the manufacturing method of the optical element according to the present embodiment will be described while omitting points common to the first embodiment as appropriate.

  The heating / pressurizing stage 2-1 in the present embodiment is the same as that in the first embodiment, except that a pulling portion 2i that pulls the position restricting member 22 from a position that restricts the position of the upper mold 21 is disposed. It is. The extraction portion 2i is held by, for example, the upper heating plate 2a and moves in the radial direction of the optical element molding die set 20.

  First, the optical material 100 is placed at the center of the upper end of the holding member 13 of the optical element molding die set 20 so that the center A3 of the optical material 100 becomes the central axis A1 of the molding surface 21a of the upper mold 21 and the lower mold 11. The upper mold 2g, the lower mold 11 and the optical material 100 are arranged so as to coincide with the center axis A2 of the molding surface 11c (centering step). Then, the optical element molding die set 20 is carried into the molding chamber 4 shown in FIG. 1, and is placed at the center of the lower heating plate 2b of the heating / pressurizing stage 2-1, as shown in FIG. 6A.

  Then, the optical material 100 that is not in contact with the molding surface 21a of the upper mold 21 and the molding surface 11c of the lower mold 11 is heated to a temperature equal to or higher than the glass yield point by the upper cartridge heater 2c and the lower cartridge heater 2d (heating). Process).

  As shown in FIG. 6B, the pulling-out portion 2i moves the position restricting member 22 of the optical element molding die set 20 after heating by the upper cartridge heater 2c and the lower cartridge heater 2d and before pressurization by a protruding member 2h described later. Then, the upper die 21 is pulled out from a position where the position of the upper die 21 is regulated (pulling step).

  Thereby, the molding surface 21a of the upper mold | type 21 contacts the heated optical raw material 100 (contact process). Thus, in the contact process of this embodiment, the position restriction member 22 is pulled out, and the restriction of the position of the upper mold 21 is released.

  Also in the present embodiment described above, the center axis A1 of the molding surface 21a of the upper mold 21, the center axis A2 of the molding surface 11c of the lower mold 11 and the center A3 of the optical material 100 coincide with each other in the centering step. To do. The optical material 100 is heated in a non-contact state with the molding surface 21a of the upper mold 21 and the molding surface 11c of the lower mold 11 (heating process), and after contacting the molding surface 21a of the upper mold 21 (contact process). Then, pressure is applied by the lower mold 11 (pressure process). Therefore, according to the present embodiment, it is possible to suppress the occurrence of spider and eccentricity in the optical element.

  In the present embodiment, the position restricting member 22 restricts the position of the upper die 21 so that the molding surface 21 a of the upper die 21 is not in contact with the optical material 100. Therefore, the molding surface 21a of the upper mold 21 can be brought into a non-contact state with the optical material 100 in a heating process with a simple configuration.

  In the present embodiment, the position regulating member 22 is disposed between the upper mold 21 and the upper end of the sleeve 12. Therefore, the molding surface 21a of the upper mold 21 can be brought into a non-contact state with the optical material 100 in a heating process with a simple configuration.

  Further, in the present embodiment, the pull-out portion 2i is configured such that the position regulating member 22 is heated after being heated by the heating portion (upper cartridge heater 2c and lower cartridge heater 2d) and before being pressurized by the pressure portion (protruding member 2h). Pull out from the position where the position of the upper die 21 is regulated. Therefore, the molding surface 21a of the upper mold 21 can be brought into contact with the optical material 100 in the contact process with a simple configuration.

  As shown in FIG. 7, the position restricting member 22-1 of the optical element molding die set 20-1 of the first modified example penetrates the sleeve 12 from the outer peripheral side to the inner peripheral side, and the lower end of the upper die 21 Support. In this case, it is possible to make it difficult for the position restricting member 22-1 to fall off the optical element molding die set 20-1.

  Further, as shown in FIG. 8, in the second modification, the gap in the height direction between the flange portion 21 b of the upper mold 21 of the optical element molding mold set 20-2 and the upper end of the sleeve 12 is within the sleeve 12. The distance increases from the circumferential side (gap G1) to the outer circumferential side (gap G2). Further, the thickness in the height direction of the position regulating member 22-2 may be increased from the inner peripheral side (height H1) to the outer peripheral side (height H2) of the sleeve 12. In this case, the position restricting member 22-2 can be easily pulled out by the pulling portion 2i shown in FIGS. 6A and 6B, for example.

<Third Embodiment>
FIG. 9 is a cross-sectional view showing an optical element molding die set 30 according to the third embodiment of the present invention.
FIG. 10 is a cross-sectional view of the heating / pressurizing stage 2-2 for explaining the method of manufacturing an optical element according to the third embodiment of the present invention.
In the optical element molding die set 30 according to the present embodiment, the lower die 11, the sleeve 12, and the holding member 13 are the same as those of the optical element molding die set 10 according to the first embodiment, and the upper die 31 is different. To do.

  In the present embodiment, the upper die 31 is not fixed to the upper heating plate 2a of the heating / pressurizing stage 2-2 shown in FIG. 10, but the optical element molding die set 30 as in the second embodiment. It is arranged as a part of.

  The upper die 31 has a molding surface 31a at the lower end and a flange portion 31b at the upper end. The height (thickness) of the flange portion 31b becomes smaller toward the outer peripheral side of the sleeve 12. Therefore, the inclined surface 31c is formed in the lower end of the flange part 31b.

  The inclined surface 31 c contacts the upper end of the sleeve 12 on the inner peripheral side of the sleeve 12, but there is a gap G between the upper end of the sleeve 12 and the outer peripheral side of the sleeve 12.

  Hereinafter, the manufacturing method of the optical element according to the present embodiment will be described while omitting points common to the first embodiment as appropriate.

  The heating / pressurizing stage 2-2 in the present embodiment is the same as that in the first embodiment except that the upper mold lifting part 2j is disposed. The upper mold lifting portion 2j is held by, for example, the upper heating plate 2a and moves in the radial direction and the height direction of the optical element molding mold set 20. The contact portion 2j-1 provided at the tip of the upper mold lifting portion 2j has a height (thickness) that decreases toward the tip, and is inserted into the gap G described above between the inclined surface 31c and the upper end of the sleeve 12. Is done.

  First, the optical material 100 is placed at the center of the upper end of the holding member 13 of the optical element molding die set 30 so that the center A3 of the optical material 100 is the central axis A1 of the molding surface 31a of the upper mold 31 and the lower mold 11. Coincides with the central axis A2 of the molding surface 11c (centering step). Then, the optical element molding die set 30 is carried into the molding chamber 4 shown in FIG. 1, and is placed at the center of the lower heating plate 2b of the heating / pressurizing stage 2-2 as shown in FIG.

  At this time, the optical material 100 is in contact with the molding surface 31 a of the upper mold 31. The upper mold lifting portion 2j lifts the upper mold 31 before heating by an upper cartridge heater 2c and a lower cartridge heater 2d described later (upper mold lifting process).

  Then, the optical material 100 in a non-contact state with the molding surface 31a of the upper mold 31 and the molding surface 11c of the lower mold 11 is heated to a temperature equal to or higher than the glass yield point by the upper cartridge heater 2c and the lower cartridge heater 2d (heating). Process).

After the heating of the optical material 100 is finished, the upper mold lifting part 2j moves in a direction away from the optical element molding mold set 20 (in the example shown in the figure, the direction that expands to the left and right) to lift the upper mold 31. Release (lift release process). Thereby, the molding surface 31a of the upper mold 31 comes into contact with the heated optical material 100 again (contact process). Thus, in this embodiment, before the contact step, the upper mold 31 is lifted by the upper mold lifting portion 2j so that the molding surface 31a of the upper mold 31 is not in contact with the optical material 100.
And a pressurization process and a cooling process are performed similarly to 1st Embodiment, and an optical element is manufactured.

  Also in the present embodiment described above, the center axis A1 of the molding surface 31a of the upper mold 31, the center axis A2 of the molding surface 11c of the lower mold 11 and the center A3 of the optical material 100 coincide with each other in the centering step. To do. Then, the optical material 100 is heated in a non-contact state with the molding surface 31a of the upper mold 31 and the molding surface 11c of the lower mold 11 (heating process) and contacts the molding surface 31a of the upper mold 31 (contact process). Then, pressure is applied by the lower mold 11 (pressure process). Therefore, according to the present embodiment, it is possible to suppress the occurrence of spider and eccentricity in the optical element.

  In the present embodiment, the upper mold lifting portion 2j is in a state in which the molding surface 31a of the upper mold 31 is not in contact with the optical material 100 while heating by the heating units (upper cartridge heater 2c and lower cartridge heater 2d) is performed. The upper mold 31 is lifted so that Therefore, the molding surface 31a of the upper mold 31 can be brought into a non-contact state with respect to the optical material 100 in the heating process with a simple configuration.

DESCRIPTION OF SYMBOLS 1 Optical element manufacturing apparatus 2 Heating / pressurizing stage 2a Upper heating plate 2b Lower heating plate
2b-1 Through-hole 2c Upper cartridge heater 2d Lower cartridge heater 2e Air cylinder 2f Base
2f-1 Through hole 2g Upper mold
2g-1 molding surface
2g-2 Flange part 2h Extruding member 2i Pull-out part 2j Upper mold lifting part
2j-1 abutting portion 3 cooling stage 3a upper heating plate 3b lower heating plate 3c upper cartridge heater 3d lower cartridge heater 3e air cylinder 3f base 4 molding chamber 10 optical element molding die set 11 lower die 11a large diameter portion 11b small diameter Part 11c Molding surface 12 Sleeve 12a Thick part 12b Thin part 12c Step part 13 Holding member 13a Flange part 20 Optical element molding mold set 21 Upper mold 21a Molding surface 21b Flange part 22 Position regulating member 30 Optical element molding mold set 31 Upper mold 31a Molding surface 31b Flange 31c Inclined surface 100 Optical material

Claims (9)

A centering step of arranging the upper mold, the lower mold, and the optical material so that the center axis of the molding surface of the upper mold and the center axis of the molding surface of the lower mold coincide with the center of the optical material;
A heating step of heating the optical material in a non-contact state with the molding surface of the upper mold and the molding surface of the lower mold;
A contact step of bringing the upper mold into contact with the heated optical material to bring the molding surface of the upper mold into contact with each other;
A pressing step of pressing the optical material in contact with the molding surface of the upper mold by moving the lower mold closer to the upper mold;
A cooling step of cooling the pressurized optical material.   In the contacting step, the position regulating member that regulates the position of the upper mold is pulled out so that the molding surface of the upper mold is in a non-contact state with the optical material, and the regulation of the position of the upper mold is released. Item 2. A method for producing an optical element according to Item 1.   The method of manufacturing an optical element according to claim 1, wherein the upper mold is lifted by an upper mold lifting portion so that the molding surface of the upper mold is in a non-contact state with the optical material before the contacting step. A sleeve that aligns the central axis of the molding surface of the upper mold and the central axis of the molding surface of the lower mold by restricting the positions of the outer peripheral portions of the upper mold and the lower mold;
The center of the optical material in a non-contact state with the molding surface of the upper mold and the molding surface of the lower mold is the central axis of the molding surface of the upper mold and the central axis of the molding surface of the lower mold And a holding member for holding the optical material so as to match
And a position restricting member for restricting the position of the upper mold so that the molding surface of the upper mold is not in contact with the optical material.   The optical element molding die set according to claim 4, wherein the position restricting member is disposed between the upper die and an upper end of the sleeve. The gap in the height direction between the upper mold and the upper end of the sleeve becomes larger from the inner peripheral side to the outer peripheral side of the sleeve,
The molding die set according to claim 5, wherein a thickness of the position restricting member in a height direction increases from an inner peripheral side to an outer peripheral side of the sleeve.   The optical element molding die set according to claim 4, wherein the position restricting member penetrates the sleeve from the outer peripheral side to the inner peripheral side and supports the lower end of the upper die. A plurality of stages to which the optical element molding die set according to any one of claims 4 to 7 is sequentially transferred,
A heating unit that is disposed on at least one of the plurality of stages and heats an optical material housed in the optical element molding die set;
A pressurizing unit that is disposed on at least one of the plurality of stages and pressurizes the optical material housed in the optical element molding die set;
An apparatus for manufacturing an optical element, comprising: a drawing portion that pulls out the position regulating member of the optical element molding die set from a position that regulates the position of the upper mold. A plurality of stages to which an optical element molding die set having an upper die arranged to face the lower die is sequentially transferred;
A heating unit that is disposed on at least one of the plurality of stages and heats an optical material housed in the optical element molding die set;
A pressurizing unit that is disposed on at least one of the plurality of stages and pressurizes the optical material housed in the optical element molding die set;
An optical element manufacturing apparatus, comprising: an upper mold lifting portion that lifts the upper mold so that a molding surface of the upper mold is in a non-contact state with the optical material.

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