KR20170099768A - Press-forming die and method for manufacturing optical element - Google Patents

Abstract

Provided is a press-molding mold which can prevent horizontal movement of an optical material when molding an optical element by using the press-molding mold comprising an upper mold, a lower mold, and a body mold and can manufacture the optical element with high molding precision. The press-molding mold (1) molds a glass lens and comprises: the lower mold (4) which has a molding surface (16A) facing the upside for molding a lower side of the glass lens; an upper mold (2) which has a molding surface (12A) facing the downside to face the molding surface (16A) of the lower mold (4) for molding an upper side of the glass lens; and common second body molds (8) having holding units (18) for holding lateral sides of the glass lens on the inner circumferential side during a press process. The holding unit (18) of the second body mold (8) has a first lower side (20) formed to face the lower mold (4), and a second lower side (22) formed under the first lower side (20) to face the lower mold (4).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a press forming die,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press forming die and a manufacturing method of an optical element, and more particularly, to a press forming die having a top die, a bottom die, and a barrel die and a manufacturing method of the optical element using the die .

Conventionally, as a method of manufacturing an optical element such as a glass lens, a method of manufacturing an optical element including a lower mold having an upward forming surface for forming a lower surface of the optical element and an upper mold having a downward shaping surface for forming an upper surface of the optical element A method of forming by using one press forming die is used. A glass material such as a preform is placed on the molding surface of the lower mold and the upper mold is lowered down to press the glass material so that the molding surfaces of the upper and lower molds are transferred to the upper and lower surfaces of the glass material, Can be manufactured.

However, when a glass lens is molded by using such a press mold, when the upper mold is pushed in, the glass material moves in the lateral direction, and the optical surface of the formed glass lens is biased, so that sufficient molding precision can not be obtained There is a case. On the other hand, for example, as disclosed in Patent Document 1 (Japanese Unexamined Patent Publication (Kokai) No. 2005-336050), there has been proposed a press-formed mold in which a conical ring-shaped surface extending downward on the inner peripheral surface of the same shape is formed. Fig. 6 is a vertical cross-sectional view showing a press-formed mold in which a conical ring-shaped surface spreading downward is formed on a conventionally used isotype. 6, the press forming die 301 includes a top die 302, a bottom die 304, a first isoform 306 surrounding the top die 302 and the bottom die 304, And a second isoform 308 disposed within the second bead 306. A conical ring annular surface 308A is formed on the inner peripheral surface of the second isoform 308 so as to extend downward in the same shape. According to the press forming die 301 as described above, when the upper mold 302 is pressed downward, the glass material is spread in the outer peripheral direction and the conical annular surface 308A presses the peripheral edge of the glass material tightly. It is possible to prevent movement in the direction.

Japanese Laid-Open Patent Publication No. 2005-336050

Here, when the glass lens is molded by using the press mold having the conical annular surface as described above, when the press mold is cooled in a state in which the glass material is pressed, the glass material is inferior to the metal material constituting the press mold Shrink greatly. 7, a frictional force F is generated between the conical annular surface 308A and the peripheral portion of the glass material 310 in contact with the conical annular surface 308A. When the large frictional force F acts on the periphery of the glass material 310 from the conical annular surface 308A at the time of shrinking of the glass material, shrinkage of the glass material 310 becomes uneven and the precision of forming the optical element is lowered. In order to reduce the frictional force between the glass material and the toroidal annular surface, it is practiced to coat the surface of the conical annular surface 308A with a coating having a reduced friction with the glass material 310. [ However, even if such a coating is applied, if a large number of optical elements are continuously produced, the coating is peeled off and the forming precision of the optical element is lowered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide an optical element which can prevent lateral movement of an optical material when a optical element is molded using a press mold having an upper mold, a lower mold, It is an object of the present invention to provide a press forming die capable of manufacturing a high optical element.

The press-molding die of the present invention comprises a lower die having an upwardly facing molding surface for molding a lower surface of an optical element, a top die having a molding surface facing downward to face a molding surface of the lower die for molding an upper surface of the optical element, And a restricting portion for restricting a side portion of the optical element on the inner circumferential side at the time of pressing, wherein the restricting portion of the same type includes a first surface formed to face the lower mold, And a second surface formed below the first surface and formed to face the lower surface.

According to the present invention having the above-described configuration, since the first surface and the second surface formed below the first surface are formed in the same-shaped restraining portion, the first surface and the second surface are formed by the outer surface of the optical material And abuts the upper surface of the outer periphery. As a result, lateral movement of the optical material during press forming can be restrained. In addition, since the second surface is formed below the first surface, the thickness of the portion where the first surface of the optical material abuts is thicker than the portion abutted against the second surface, Shrinkage also increases. Therefore, at the time of cooling, only the second surface is in contact with the optical material, and the first surface is separated from the optical material. Thereby, even when the optical element is shrunk in the radial direction when it is cooled, the frictional force of the same-shaped restraining portion becomes very small, and the optical element can be manufactured with high molding precision.

A method of manufacturing an optical element according to the present invention includes the steps of arranging an optical material between a press-formed mold and a lower mold, a step of heating a press-mold provided with the optical material, and a press- And press-molding the optical material.

According to the present invention, it is possible to prevent lateral movement of an optical material when forming an optical element by using a press-molding die having an upper die, a lower die, and a die, The present invention is not limited thereto.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical sectional view showing a press-molding die according to a first embodiment of the present invention. Fig.
Fig. 2 is a vertical cross-sectional view enlargedly showing the vicinity of a second isometric restricting portion when manufacturing a glass lens using the press-molding die of the first embodiment. Fig.
3 is a vertical sectional view showing a press-molding die according to a second embodiment of the present invention.
4 is a vertical sectional view showing a press-molding die according to a third embodiment of the present invention.
5 is a graph showing a thickness error with respect to design values in Comparative Examples and Examples.
6 is a vertical cross-sectional view showing a press-formed mold in which a conical ring-shaped surface spreading downward in a conventionally used uniform shape is formed.
Fig. 7 is a vertical cross-sectional view showing an enlarged view of the vicinity of the conical annular surface at the time of pressing the press mold of the conventionally used type.

Hereinafter, a first embodiment of the press-forming die of the present invention will be described in detail with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical sectional view showing a press-molding die according to a first embodiment of the present invention. Fig. As shown in the figure, the press-molding die 1 of the present embodiment has an upper mold 2 having a molding surface 12A corresponding to the upper surface of the optical element in the lower portion, The lower mold 4 having the molding surface 16A and the first mold 6 formed on the outer periphery of the upper mold 2 and the lower mold 4 and the outer periphery of the upper mold are also formed on the inner side of the first mold 6, And a restricting portion (18) for restricting the side portion of the glass material. The press-molding die 1 of the present embodiment is for producing a meniscus lens whose one surface is convex and whose other surface is concave.

The upper die 2 has a base portion 10 formed in a cylindrical shape and a molding portion 12 protruding downward from a lower portion of the base portion 10. The molding part 12 has a cylindrical shape with a smaller diameter than the base part 10 and a convex molding surface 12A corresponding to the concave surface of the glass lens (optical element) to be manufactured is formed on the lower surface.

The lower mold 4 has a cylindrical portion 14 formed in a cylindrical shape and a molding portion 16 protruding upward from the upper portion of the base portion 14. The molding section 16 has a cylindrical shape with a smaller diameter than the base section 14 and a concave molding surface 16A corresponding to the convex surface of the glass lens to be manufactured is formed on the upper surface.

The first isoform 6 is made of a member formed in a substantially cylindrical shape. The inner diameter of the first isoform 6 is equal to the outer diameter of the base 10 of the upper die 2. The upper die 2 is inserted into the first die 6 from above. The inner diameter of the lower portion of the first isoform 6 is formed to be substantially equal to the outer diameter of the forming portion 16 of the lower die 4. The lower end of the first isometric 6 is in contact with the upper surface of the peripheral edge of the base 14 of the lower die 4. The lower end of the lower die 4 is inserted into the first shoulder 6 from below.

The second isoform 8 represents an annular shape, and the outer peripheral surface represents a cylindrical surface. The first cylindrical portion 19, the first lower surface 20, the second lower surface 22 and the second cylindrical portion 24 are formed continuously from the upper side on the inner periphery of the second isoform 8, . The first cylindrical portion 19 indicates a cylindrical surface, and extends in the upward direction. The inner diameter of the first cylindrical portion 19 is substantially equal to the outer diameter of the molding portion 12 of the upper die 2. [ The first lower surface 20 is formed as a conical ring annular surface extending downward and the first lower surface 20 is directed diagonally downward toward the center side of the press forming die 1. The second lower surface 22 is an annular surface centered on the center axis (indicated by the one-dot chain line in the figure) of the press forming die 1 and is vertical with respect to the center axis of the press forming die 1. The second lower surface 22 is mirror-finished and coated with an FCVA film. The second cylindrical portion 24 shows a cylindrical surface. Preferably the surface area of the second lower surface 22 is smaller than the surface area of the first lower surface 20 and more preferably the projected area of the second lower surface 22 in the direction of the central axis of the press- Is smaller than the projection area of the lower surface 20 in the center axis direction of the press forming die 1. [ In this embodiment, the first lower surface 20, the second lower surface 22 of the second type 8 and the second cylindrical portion 24 constitute the restricting portions 18 of the second type 8 ).

The second isoform 8 is arranged above the forming portion 16 of the lower mold 4 on the inner side of the first isoform 6 and on the outer periphery of the forming portion 12 of the upper mold 2, The molding part 12 of the upper die 2 is inserted. The lower peripheral edge portion of the base portion 10 of the upper die 2 comes into contact with the upper surface of the second die die 8 in a state in which the press forming die 1 is assembled. The center axes of the upper die 2, the lower die 4, the first iso 6 and the second iso 8 coincide with each other when the press-formed die 1 is assembled. 1 shows a state in which the bottom portion of the second type 8 abuts against the upper surface of the lower die 4. However, at the time of pressing, the press starts from the separated state.

Fig. 2 is a vertical sectional view enlarging the vicinity of the second-type restricting portion 18 when the glass lens is produced by using the press-molding die of the first embodiment. The glass material 26 such as a preform is placed on the molding surface 16A of the lower mold 4 while the upper mold 2 and the second mold 8 are removed. Then, the second isoform 8 is disposed in the first iso 6, and then the second iso is placed in the first iso 6. Thus, the press forming die 1 in which the glass material 26 is disposed is heated to a temperature equal to or higher than the glass yielding point.

When the glass material 26 is sufficiently heated to a temperature equal to or higher than the glass yielding point, the upper die 2 is pushed downward by a press device such as a hydraulic actuator in a state of supporting the lower die 4. The upper and lower molds 2 and 8 are pushed down so that the center axes of the upper and lower molds 2 and 8 are moved by the lower mold 4 ) While maintaining a state coinciding with the center axis of the lower portion.

When the upper mold 2 descends, first, the center portion of the molding surface 12A of the upper mold 2 comes into contact with the upper surface of the glass material 26. [ Further, as the upper die 2 descends, the glass material 26 is crushed and unfolded toward the side. At this time, as shown in Fig. 2, the second lower surface 22 of the second isoform 8 abuts on the peripheral edge of the upper surface of the glass material 26, and the second lower surface 22 of the upper surface of the glass material 26 22 are in contact with each other. Thereby, the lateral movement of the glass material 26 is reliably prevented. In this state, the upper die 2 is again pushed up until the upper surface of the upper die 2 comes into contact with the upper surface of the first die 6, so that the upper die 2 and the lower die 4 are transferred onto the molding surfaces 12A, 16A. At this time, the inner portion of the second bottom surface 22 of the glass material 26 (the portion below the first bottom surface 20) advances upward, And a gap is formed between the glass material 26 and the upper portion of the first surface 20. In this manner, a gap is formed between the upper portion of the first lower surface 20 and the glass material 26, so that the deviation of the volume of the glass material 26 can be absorbed.

Then, the press mold 1 is cooled in such a state that a press pressure is applied to the top mold 2 as described above. At this time, the portion of the glass material 26 that is in contact with the first bottom surface 20 is thicker than the portion of the glass material 26 that is in contact with the second bottom surface 22. Therefore, the portion of the glass material 26 abutting against the first lower surface 20 is contracted greatly in the thickness direction as compared with the portion abutting against the second lower surface 22. The second lower surface 22 is held in contact with the upper surface of the glass material 26 because the pressing force is applied to the upper mold 2 at the time of cooling. . Further, even if the glass material 26 is not separated from the first bottom surface 20, the press pressure acting between the glass material 26 and the first bottom surface 20 becomes very small.

When the glass material 26 is shrunk, the outer peripheral portion of the glass material 26 moves toward the radial center. At this time, frictional force acts between the upper surface of the outer peripheral portion of the glass material 26 and the second lower surface 22 of the second isosceles 8. However, according to the present embodiment, as described above, the first bottom surface 20 and the glass material 26 are separated from each other, or the press pressure (pressure) acting between the glass material 26 and the first bottom surface 20 The frictional force acting in the radial direction between the glass material 26 and the restricting portion 18 of the second isoform 8 becomes very small. Therefore, the glass material 26 shrinks uniformly in the radial direction.

As described above, according to the present embodiment, the first lower surface 20 and the second lower surface 22 abut on the upper surface of the outer periphery of the glass material 26 during press forming. Thereby, it is possible to restrain the movement of the glass material 26 in the lateral direction at the time of press forming. According to the present embodiment, the first lower surface 20 is separated from the upper surface of the glass material 26 at the time of cooling. Thus, even if the glass material 26 is shrunk during cooling of the glass material 26, frictional force is generated only between the second lower surface 22 and the glass material 26, and the glass material 26 is transferred from the restricting portion 18, The frictional force in the radial direction acting on the glass lens becomes very small, and the glass lens can be manufactured with high molding precision.

According to the present embodiment, the surface area of the second lower surface 22 is smaller than the surface area of the first lower surface 20. This makes it possible to reduce the frictional force between the second lower surface 22 and the glass material 26 at the time of cooling.

According to the present embodiment, since the first lower surface 20 is formed, a gap is formed between the glass material 26 and the first lower surface 20 below the glass material 26, The volume error can be absorbed.

Hereinafter, a press forming die according to a second embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

3 is a vertical sectional view showing a press-molding die according to a second embodiment of the present invention. As shown in the figure, the press-molding die 101 of the present embodiment has an upper die 2 having a molding surface 12A corresponding to the upper surface of the optical element in the lower portion, The lower mold 4 having the molding surface 16A and the first mold 6 formed on the outer periphery of the upper mold 2 and the lower mold 4 and the outer periphery of the upper mold are also formed on the inner side of the first mold 6, And a second isoform 108 having a restricting portion 118 for restraining the glass material as will be described later. Since the configurations of the upper die 2, the lower die 4 and the first die 6 are the same as those of the first embodiment, a detailed description thereof will be omitted.

The second isoform 108 shows a ring shape, and the outer peripheral surface shows a cylindrical surface. A first cylindrical portion 119, a first lower surface 120, a second cylindrical portion 121, a second lower surface 122, and a third cylindrical portion 121 are formed on the inner periphery of the second isoform 108 from above. And a cylindrical portion 124 is continuously formed. The first cylindrical portion 119 represents a cylindrical surface, and extends in the vertical direction. The inner diameter of the first cylindrical portion 119 is substantially equal to the outer diameter of the forming portion 12 of the upper die 2. [ The first lower surface 120 is formed so as to face diagonally downward toward the center side of the press-formed die 101, and shows a toroidal annular surface. The second cylindrical portion 121 indicates a cylindrical surface, and extends in the vertical direction. The inner diameter of the second cylindrical portion 121 is larger than that of the first cylindrical portion 119 and smaller than that of the third cylindrical portion 124. The second lower surface 122 is an annular surface centered on the center axis (indicated by a dashed line in the figure) of the press forming die 101 and is perpendicular to the central axis of the press forming die 101. The second lower surface 122 is mirror-polished and coated with an FCVA film. The third cylindrical portion 124 shows a cylindrical surface.

The surface area of the second lower surface 122 is preferably smaller than the surface area of the first lower surface 120 and more preferably the projected area of the second lower surface 122 in the direction of the central axis of the press- Is smaller than the projection area of the lower surface 120 in the direction of the central axis of the press forming die 101. In the present embodiment, the first bottom surface 120, the second cylindrical portion 121, the second bottom surface 122, and the third cylindrical portion 124 of the second isoform 108, The restraining portion 118 of the male mold 108 is formed.

The second isoform 108 is disposed above the forming portion 16 of the lower mold 4 on the inner side of the first isoform 6 and on the outer periphery of the forming portion 12 of the upper mold 2, 2 is inserted into the first cylindrical portion 119. [0154] The lower peripheral edge portion of the base portion 10 of the upper die 2 comes into contact with the upper surface of the second die die 8 in a state in which the press forming die 101 is assembled. The center axes of the upper die 2, the lower die 4, the first iso 6 and the second iso 108 coincide with each other when the press-formed die 101 is assembled. 3 shows a state in which the bottom portion of the second isoform 108 is in contact with the upper surface of the lower die 4. However, at the time of pressing, the press starts from the separated state.

The press mold 101 of the second embodiment also exhibits the same operational effects as the press mold 1 of the first embodiment.

That is, when the upper die 2 is lowered at the time of press forming, the glass material is pressed and collapsed, and is spread toward the side. At this time, the second lower surface 122 of the second isoform 108 abuts against the peripheral edge of the upper surface of the glass material, and the first lower surface 120 ). Thereby, it is possible to restrain the lateral movement of the glass material.

Since the portion of the glass material contacting the first lower surface 120 is thicker than the portion of the glass material contacting the second lower surface 122, The shrinkage in the thickness direction is large in the portion where the bottom surface 120 is abutted. Since the pressing force is applied to the upper mold 2 also during cooling, only the second lower surface 122 comes into contact with the glass material, and the first lower surface 120 is separated from the glass material. As a result, even when the glass material contracts in the radial direction during cooling, frictional force is generated between the glass material and the second lower surface 122 only, and the frictional force acting on the glass material becomes very small, And can be manufactured with precision.

According to the present embodiment, the surface area of the second lower surface 122 is smaller than the surface area of the first lower surface 120. Thereby, the frictional force between the second lower surface 122 and the glass material at the time of cooling can be further reduced.

According to the present embodiment, since the first bottom surface 120 is formed, a gap is formed between the glass material and the first bottom surface 120 below the first bottom surface 120, whereby the volume error of the glass material can be absorbed have.

In the present embodiment, the second lower surface 122 is parallel to the plane vertical to the central axis of the press-formed die 101. However, the present invention is not limited to this, It may be formed so as to face diagonally downward toward the center of the mold 101. When the first lower surface 120 and the second lower surface 122 are formed so as to face diagonally downward toward the center of the press forming die 101 as described above, (I.e., the angle of the second lower surface 122 with respect to the left and right direction in Fig. 3) with respect to the direction orthogonal to the central axis is larger than the direction perpendicular to the central axis of the press forming die 101 of the first lower surface 120 As shown in FIG. The angle of the first bottom surface 120 with respect to the direction perpendicular to the center axis of the press forming die 101 is 30 degrees or less and the angle of the second bottom surface 120 with respect to the center axis of the press forming die 101 The angle with respect to the in-plane direction is 10 degrees or less.

Hereinafter, a press forming die according to a third embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

4 is a vertical sectional view showing a press-molding die according to a third embodiment of the present invention. As shown in the figure, the press-molding die 201 of the present embodiment has an upper die 2 having a molding surface 12A corresponding to the upper surface of the optical element at the lower portion, The lower mold 4 having the molding surface 16A and the first mold 6 formed on the outer periphery of the upper mold 2 and the lower mold 4 and the outer periphery of the upper mold are also formed on the inner side of the first mold 6, And a second isoform 208 having a restraining portion 218 for restraining the glass material as described later. Since the configurations of the upper die 2, the lower die 4 and the first die 6 are the same as those of the first embodiment, a detailed description thereof will be omitted.

The second isoform 208 shows a ring shape, and the outer peripheral surface shows a cylindrical surface. The first cylindrical portion 219, the first lower surface 220, the second cylindrical portion 221, the second lower surface 222, and the third cylindrical portion 219 are formed on the inner periphery of the second isoform 208 from above. And a cylindrical portion 224 is formed continuously.

The first cylindrical portion 219 indicates a cylindrical surface, and extends in the vertical direction. The inner diameter of the first cylindrical portion 219 is substantially equal to the outer diameter of the forming portion 12 of the upper die 2. The first lower surface 220 is an annular surface centered on the central axis (indicated by a dot-dash line in the figure) of the press forming die 201 and is vertical to the central axis of the press forming die 201 . The outer diameter of the first lower surface 220 is equal to the inner diameter of the second cylindrical portion 221. The second cylindrical portion 221 indicates a cylindrical surface, and extends in the vertical direction. The inner diameter of the second cylindrical portion 221 is larger than that of the first cylindrical portion 219 and smaller than that of the third cylindrical portion 224. The second lower surface 222 is an annular surface centered on the center axis (indicated by a dashed line in the figure) of the press forming die 201, and is perpendicular to the central axis of the press forming die 201. The second lower surface 222 is subjected to mirror-surface processing and coated with an FCVA film. The third cylindrical portion 224 shows a cylindrical surface.

The surface area of the second lower surface 222 is preferably smaller than the surface area of the first lower surface 220 and more preferably the projected area of the second lower surface 222 in the direction of the central axis of the press- Is smaller than the projection area of the lower surface 220 in the direction of the central axis of the press forming die 201. In the present embodiment, the first bottom surface 220, the second cylindrical portion 221, the second bottom surface 222, and the third cylindrical portion 224 of the second isoform 208 form a second The restraining portion 218 of the male mold 208 is formed.

The second isoform 208 is disposed above the forming portion 16 of the lower mold 4 on the inner side of the first isoform 6 and on the outer periphery of the forming portion 12 of the upper mold 2, 2 is inserted in the inside of the first cylindrical portion 219. As shown in Fig. The lower peripheral edge portion of the base portion 10 of the upper die 2 comes into contact with the upper surface of the second die die 8 in a state in which the press forming die 201 is assembled. The center axes of the upper die 2, the lower die 4, the first iso 6 and the second iso 208 coincide with each other in the state where the press-formed die 201 is assembled. 4 shows a state in which the bottom portion of the second isoform 208 is in contact with the upper surface of the lower die 4. However, at the time of pressing, the press starts from the separated state.

The press-molding die 201 of the third embodiment exhibits the same operational effects as the press-molding die 1 of the first embodiment.

 That is, when the upper die 2 is lowered at the time of press forming, the glass material is pressed and collapsed, and is spread toward the side. At this time, the second lower surface 222 of the second isoform 208 abuts against the peripheral edge of the upper surface of the glass material, and the first lower surface 220 ). Thereby, the lateral movement of the glass material can be surely restrained.

Since the portion of the glass material contacting the second lower surface 222 is thicker than the portion of the glass material contacting the first lower surface 220, The shrinkage in the thickness direction is large in the portion where the lower surface 220 is in contact. Since the pressing force is applied to the upper die 2 also during cooling, only the second lower surface 222 comes into contact with the glass material, and the first lower surface 220 is separated from the glass material. Thus, even if the glass material contracts in the radial direction during cooling, a frictional force is generated between the glass material and the second lower surface 222 only, and the frictional force acting on the glass material becomes very small, And can be manufactured with precision.

According to the present embodiment, the surface area of the second lower surface 222 is smaller than the surface area of the first lower surface 220. Thereby, the frictional force between the second lower surface 222 and the glass material at the time of cooling can be further reduced.

According to the present embodiment, since the first lower surface 220 is formed, a gap is formed between the glass material and the first lower surface 220 below the first lower surface 220, thereby making it possible to absorb the volume error of the glass material have.

In the present embodiment, the case where the second lower surface 222 is parallel to the plane vertical to the central axis of the press-formed mold 201 has been described. However, the second lower surface 222 is not limited to this, It may be formed so as to face diagonally downward toward the center of the mold 201.

In the above-described embodiments, a glass lens is manufactured by press molding a glass material. However, the present invention is not limited to this. In a case where an optical element made of another material such as a plastic lens is press molded .

Here, the inventors of the present invention have found that by using the press-molding type (embodiment) of the first embodiment described with reference to Fig. 1 and the conventional press-molding type (comparative example) described with reference to Fig. 6, And the thicknesses at three points on each of the orthogonal XY axes of the glass lens thus manufactured were measured to calculate an error from the design value. 5 is a graph showing a thickness error with respect to design values in Comparative Examples and Examples. As shown in Fig. 5, in the press-molding die of the comparative example, the thickness error tends to increase as the number of shots increases. On the contrary, according to the press-molding die of the embodiment, it is understood that the error with respect to the design value is shifted to a very small value even if the number of shots increases. Thus, according to the present invention, it was confirmed that it is possible to manufacture an optical element having high molding accuracy even when a large number of glass lenses are continuously manufactured.

Hereinafter, the present invention will be described with reference to the drawings.

As shown in Fig. 1, the press-molding die 1 of the first embodiment of the present invention includes a lower die 4 having a molding surface 16A directed upward to form a lower surface of a glass lens, An upper mold 2 having a molding surface 12A directed downward so as to oppose the molding surface 16A of the lower mold 4 for molding the upper surface and a restricting portion 12 for restricting the side portion of the glass lens on the inner circumferential side at the time of pressing Wherein the restricting portion 18 of the second isoform 8 is formed so as to face the lower mold 4 so as to face the lower mold 4, And a second lower surface 22 which is formed below the first lower surface 20 and is formed so as to face the lower surface 4. [

3, the press mold 101 of the second embodiment of the present invention includes a lower mold 4 having a molding surface 16A directed upward to form a lower surface of a glass lens, An upper mold 2 having a molding surface 12A directed downward so as to oppose the molding surface 16A of the lower mold 4 for molding the upper surface and a restricting portion 12 for restricting the side portion of the glass lens on the inner circumferential side at the time of pressing The restraining portion 118 of the second isoform 108 is a press molding die 101 for molding a glass lens having a conventional second isoform 108 having a lower end And a second lower surface 122 formed below the first lower surface 120 and formed to face the lower surface 4. The first lower surface 120 and the second lower surface 122 are formed on the lower surface 120,

As shown in Fig. 4, the press forming die 201 of the third embodiment of the present invention includes a lower die 4 having a forming surface 16A directed upward to form the lower surface of a glass lens, An upper mold 2 having a molding surface 12A directed downward so as to oppose the molding surface 16A of the lower mold 4 for molding the upper surface and a restricting portion 12 for restricting the side portion of the glass lens on the inner circumferential side at the time of pressing The restraining portion 218 of the second isoform 208 is a press molding die 201 for molding a glass lens having a conventional second isoform 208 having a plurality of recesses 218 And a second lower surface 222 formed below the first lower surface 220 and formed to face the lower surface 4. The first lower surface 220 and the second lower surface 222 are formed on the lower surface 220. [

1: Press forming type
2: HYPER
4: Lower mold
6: First type
8: second homogeneous
10: donation
12:
12A: Molding surface
14: donation
16:
16A: Molding surface
18:
19: first cylinder portion
20: First
22: The second
24:
101: Press forming die
108: second homogeneous type
118:
119: first cylindrical portion
120:
121: second cylindrical portion
122: the second
124: third cylinder part
201: Press forming type
208:
218:
219:
220: First
221: second cylinder portion
222: the second
224: third cylinder part

Claims (9)

A lower mold having a molding surface facing upward to mold the lower surface of the optical element, a top mold having a molding surface facing downward so as to face the molding surface of the lower mold for molding the upper surface of the optical element, A press-molding die for molding an optical element having a conventional optical element having a restricting portion for restricting a side portion of an optical element,
The restricting portion
A first surface formed to face the lower mold,
And a second surface formed below the first surface and formed to face the lower surface. The method according to claim 1,
The molding surface of the lower mold is concave,
Wherein the upper molding surface has a convex shape. 3. The method according to claim 1 or 2,
Wherein the first surface is formed diagonally downward toward the center of the press-molding die,
Wherein the second surface is perpendicular to the central axis of the upper and lower molds,
Wherein the first surface and the second surface are continuous. 3. The method according to claim 1 or 2,
Wherein a cylindrical vertical surface parallel to the central axis of the press-formed die is interposed between the first surface and the second surface. 5. The method of claim 4,
Wherein the first surface is formed so as to face diagonally downward toward the center of the press-molding die. 5. The method of claim 4,
And the second surface is formed diagonally downward toward the center of the press-molding die. 3. The method according to claim 1 or 2,
Wherein the first surface and the second surface are formed so as to face diagonally downward toward the center of the press-molding die,
Wherein an angle of the second surface with respect to a direction perpendicular to the central axis of the press-formed die is smaller than an angle with respect to a direction perpendicular to the central axis of the press-formed die of the first surface. The method according to claim 1,
Wherein the surface area of the second surface is smaller than the surface area of the first surface. Placing an optical material between the upper mold and the lower mold of the press-molding die according to claim 1;
A step of heating the press-molding die in which the optical material is disposed;
And press-molding the optical material by applying press pressure to the heated press-molding die.

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