JPH02133325A - Method for molding optical element - Google Patents

Abstract

PURPOSE:To eliminate sink marks and to provide the optical element usable as it is to optical applications by heating the optical element in such a manner that the thin part of a glass part attains the temp. higher than the temp. in the thick part at the time of press-molding the optical element by using a metallic mold for molding. CONSTITUTION:The glass stock 3 on a transporting tray 14 is moved into a heating furnace 81 by moving and controlling a transporting arm 5 and is heated and softened to the viscosity at which the stock can be molded. The front ends of an upper temp. control rod 82 and a lower temp. control rod 83 are then brought into contact (or proximity) with the front and rear glass surfaces of the glass stock 3 and the central thick part of the glass stock 3 is controlled to the temp. lower than the temp. in the peripheral thin part. The transporting arm 5 is then moved into a molding section chamber where the glass stock is pressed and molded by the upper mold and the lower mold, by which the optical element is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for molding an optical element in which an optical material such as glass is pressure molded while being heated and softened.

[Conventional technology]

Conventionally, in a method of heating and softening a glass material and then press-molding an optical element using a mold, a pair of molds having molding surfaces corresponding to the shape of the desired optical element are used. .

Further, Japanese Patent Application No. 62-306509 discloses a method in which one of the molding molds is divided into annular zones, and an optical element is press-molded while separately setting the temperature of the divided portions.

[Problem to be solved by the invention]

Generally, when pressing a glass material with a molding die to mold an optical element, the molding die is heated to about the glass transition point and the glass material is heated to about the softening point.

Therefore, in the above-mentioned method of molding an optical element using a pair of molding molds having desired molding surfaces, when molding is performed using glass materials with a large difference in wall thickness, part of the glass material may be formed first during press molding. The solidified part receives all the pressing force, and no pressure is applied to the high temperature part that has not yet sufficiently solidified, and when the molding is completed, the temperature is high and no pressure is applied. A problem has arisen in that the parts that have been removed become sinks and do not turn over to a predetermined shape.

FIGS. 17 and 18 show the above state. First, the glass material is heated uniformly throughout without temperature distribution, as shown in FIG. 17a. Thereafter, when this glass material is pressed with a molding die whose temperature is lower than that of the glass material, as shown in FIG. 17, the thin wall portion becomes cold and solidification progresses, but the thick wall portion remains at a high temperature. Ru. In other words, even when the thin-walled part solidifies and cannot be press-formed after that, it is still in a high-temperature state, so when the glass material reaches room temperature (cools down) in this state, the thick-walled part forms as shown in FIG. 17C. This will cause sink marks. FIG. 18 shows the change in the internal temperature of the glass material over time, with the temperature T of the glass material on the vertical axis and the time t on the horizontal axis, and the center part j of the glass surface and the thick wall at the cross-sectional position of the glass material. The temperature of the thin center portion 1c (see FIG. 17a) is shown in the center. That is, at time t0, points 1, 1, and j of the glass material are heated and softened to the same temperature, but when pressed by a molding die, the temperature decreases and the glass material deforms at time t3. After that, 1. At this point, the two points have solidified and no longer deform when pressed, but point k has not completely solidified. The amount of shrinkage until completely solidified is 2
Since there are more points than dots, sink marks will occur (Fig. 17C
reference).

Furthermore, in the method of molding an optical element in Japanese Patent Application No. 62-306509, one molding mold is divided into annular zones, and each of the divided annular molds is heated separately. Since the thin and thick parts of the glass material are adjusted and press-molded separately, there will be no sink marks on the optical element. ), the glass surface must be polished, and there is a problem in that the optical element press-molded by the molding die cannot be immediately used for optical purposes.

The present invention has been made in view of the above problems, and includes:
It is an object of the present invention to provide a method for molding an optical element that is free from sink marks and can be used as is for optical purposes.

[Means to solve the problem]

In order to achieve the above object, in the optical element molding method of the present invention, the glass material is heated and softened, and then the glass material is press-molded using a molding die. At this time, the glass material is heated so that the thinner part has a higher temperature than the thicker part.

[Function] According to the method for molding an optical element having the above configuration, when heating and softening the glass material, the temperature of the thin part of the glass material is made higher than the temperature of the thick part, so that the molding metal used in the next step is heated. When a glass material is press-molded using a mold, the temperature difference inside the glass material disappears when the reversal is completed. Therefore, there are no heat spots and no sink marks occur on the molded lens.

〔Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

(First Example) FIG. 1 is a sectional view showing a molding apparatus 1 for carrying out a first example of the method for molding an optical element according to the present invention, and FIG. 2 is a heating chamber 2 in the molding apparatus l. This embodiment is an example of a method for pressure forming a convex glass element with a thick central portion.

The molding device 1 includes a transport chamber 4 for transporting glass material 3 to be molded and optical elements (spherical lenses, aspheric lenses, etc.) that have been molded, and a transport arm 5 of the transport chamber 4 for transporting the glass material 3 and the optical elements (spherical lenses, aspheric lenses, etc.) that have been molded. The molding chamber 6 includes a molding chamber 6 for press-molding the glass material 3, and a heating chamber 2 disposed between the transfer chamber 4 and the molding chamber 6.

The transfer chamber section 4 and the molding chamber section 6 each have a transfer chamber frame 8. The molding chamber is sealed by a frame 9, and each chamber 4.6 is supported by a device main frame 10.

The transfer chamber section 4 includes the transfer chamber frame 8 and the transfer mechanism section 1.
1, a standby base 121 fixedly held in an upright manner on the top of the transfer chamber frame 8, a recovery tower 13, and a standby base 121 disposed at the bottom of the transfer chamber frame 8, cooperating with the standby base 12 and the recovery tower 13, respectively. The transport tray 14 (on which the glass material 3 is placed) in the collection tower 13 is set on the moving arm 5, and the transport tray 14 on which the molded optical element is placed is collected into the collection tower 13. It is composed of a special equipment section actuator 15 and a recovery section actuator 16.

The transport mechanism unit 11 transports the glass material 3 set at a predetermined position on the transport arm 5 into the heating chamber 2 or the molding chamber 6, and transports the molded product (optical element) that has been molded. The transfer arm 5. It is composed of a II transporter main body 17, a drive device 18 such as a motor, and the like.

*The feed arm 5 is connected to the drive device 18 as shown in FIG.
A ball screw shaft 19. It is configured to be able to freely control movement in the left-right direction (direction of arrow 22) in FIG. 1 via a ball housing 20 screwed onto a ball screw shaft 19 and a pair of linear slides 21. At the tip of the transfer arm 5, as shown in FIG.
and the standby shaft 2 in each of the actuators 15 and 16 above.
51 is formed with a hole 27 having a larger diameter than the shaft diameter of the collection shaft 26, and the fitting portion 23 and the hole 27 are formed concentrically.

The standby base 12 is a transport tray on which the glass material 3 to be formed is placed (set)! It is configured so that a plurality of transfer plates 14 can be stored and supported, and the transfer plates 14 stored and supported inside can be fitted and set one by one onto the transfer arm 5 at the lower position. As shown in FIG. 5, inside the tower body 28 of the standby base 12, a motor
9. Two chains 33.34, which are rotationally driven via timing belts 30, 31.32, are arranged vertically and parallel to each other, and each chain 33.3 is driven by a motor 29.
4 in the direction of the arrow 35, the conveyor tray supports fixed to each chain 33, 34 can be configured to convey the conveyor trays 14 supported by the portions 36 downward one by one. be.

A flange portion 28a is formed in the lower part of the tower body 28, and the tower body 28 is configured to be detachably fixed to the transfer chamber frame 8 via a fixing member 37 screwed thereto. Reference numeral 38 indicates an O-ring.

The recovery tower 13 has the same structure as the standby unit 12 described above.

However, the recovery tower 13 is used to place optical elements that have been completely molded.
It is for accommodating the accommodated transport trays 14 one by one.
The configuration is such that the transport plates 14 can be stored one by one in the empty tower main body 28 from the bottom to the top.

The special equipment actuator 15 is fixed to the apparatus main body frame 10 at a position below the standby base 12.

The molding chamber 6 is composed of an upper mold 50 for press-molding the glass material 3 in the transport tray 14, a push-up mechanism section 60 for moving the transport tray 14 toward the upper mold 41, and the like.

The upper mold 50 is configured to be vertically movable via an air cylinder 52. This upper mold 50 is fitted into the axial center hole of a sleeve 52 attached to the molding chamber frame 9 via a heat insulating material 51, and the upper mold 50 is slidably guided by this sleeve 52 and moves up and down. It is now possible to do so.

A heater 5 for heating the upper die 50 is provided on the outer periphery of the sleeve 52.
3 is equipped. At the bottom of the sleeve 52, there is a conveyor tray 1.
A tapered guide surface 54 that can be fitted with the outer circumferential tapered surface (tapered guide surface for axle base connection with the upper mold 5o) 14c of the annular protrusion 14b for housing the glass material 3 in 4 is formed. .

The special equipment actuator 15 is equipped with a standby shaft 25 that can be freely controlled to move in the axial direction, as shown in FIG. 6a.

As shown in b and c (by moving the standby shaft 25 upward to support the lowest transport tray 14 in the standby base 12 at its upper end, and then moving it downward, the transport trays 14 are placed on standby one by one). It is configured so that it can be taken out downward from the base 12. Reference numeral 39 indicates an O-ring for a hermetic seal.

The recovery section actuator 16 is fixed to the apparatus main body pedestal 10 at a position below the recovery tower 13, and is formed using a standby shaft 26 of the recovery section actuator 16 in a process opposite to that of the special equipment section actuator 15. 40 is an O-ring for airtight sealing.

The push-up mechanism section 50 is composed of a lower die 61 for pushing up the transfer plate 14, a push-up shaft section 62, a drive section 63 for driving the lower die 61 in the axial direction (vertical direction), and the like. The lower mold 61 is equipped with a heater 64 for heating the lower mold 61. Reference numeral 65 indicates a heat insulating material, and reference numeral 6G indicates an O-ring for sealing.

The inside of the molding chamber 70 in the molding chamber section 6 is evacuated through a pipe 71 and is set so that an inert gas can be injected into the molding chamber 70 through a pipe 72.

The heating chamber section 2 includes a heating furnace 81 equipped with a heater 80 for heating and softening the glass material 3 held on the transfer arm 5, and an upper temperature control rod 82 for partially adjusting the temperature of the glass material 3. It is composed of a lower temperature control rod 83 and the like.

The upper temperature control rod 82 and the lower temperature control rod 83 are respectively connected to the heating furnace 8I.
An air cylinder or the like is installed coaxially with the glass material 3 at the stop position (heating position) in the heating furnace 81 by penetrating the upper and lower furnace walls of the glass material 3, and is fixed to the molding chamber frame 9 of the molding chamber section 6. It is held by an upper actuator 84 and a lower actuator 85 so as to be able to approach and move away from the glass material 3. Upper temperature control rod 82 and lower a3J1 rod 83
Temperature control tubes 82a and 83a are provided inside the temperature control tubes 82a and 83a, respectively, and the temperature of the tips of the upper and lower temperature control rods 8283 is adjusted by constantly circulating 2 yt of inert gas such as N□ gas into the temperature control tubes 82a and 83a. I'm starting to get it.

In addition, in the figure, the pipes for inflowing and outflowing the inert gas into the temperature control pipes 82a and 83a are omitted.

Further, the tips of the upper temperature control rod 82 and the lower temperature control rod 83 are formed in shapes corresponding to the upper and lower glass surfaces of the glass material 3, respectively, so that when the glass material 3 is heated, the upper and lower glass surfaces are heated. It is possible to partially adjust the temperature of the upper and lower glass surfaces to a predetermined temperature by stopping them in contact with or in close proximity to the glass surface. That is, in this embodiment, the temperature of the thick portion (central portion) of the glass material 3 can be lowered than the temperature of the thin portion (periphery).

Next, a method of molding an optical element using the molding apparatus 1 will be explained.

First, the transfer arm 5 is moved via the drive device 18 so that its fitting portion 23 is located directly below the standby diameter 12, and then stopped.

Next, the standby shaft 25 is moved upward and stopped when the standby shaft 25 passes through the hole 27 of the transfer arm 5 and reaches a position below the standby diameter 12. Next, each chain 33 in the standby base 12
．． 34 in the direction of the arrow 35, and the transport tray 14 is placed on the standby shaft 25 as shown in FIG. 6a. Next, as shown in FIG. 6, after each chain 33, 34 is rotated, the standby shaft 25 is moved downward. During this downward movement operation, the transport tray 14 is fitted onto the fitting portion 23 of the transport arm 5. The conveyor tray 14 and the fitting part 23 are connected to each other by mutually tapered fitting parts 14a and 2.
3 to ensure an accurate fit. The standby shaft 25 is moved down to a position where the movement of the transport arm 5 is not hindered.

Next, the transfer arm 5 is controlled to move so that the transfer plate 14 is accommodated in the heating furnace 81, and the glass material 3 is heated. In this heating step, the glass material 3 is heated and softened to a moldable viscosity.

In this embodiment, in particular, in the heating step, the tips of the upper and lower glass surfaces of the glass material 3 are brought into contact with (or very close to) the upper and lower glass surfaces of the glass material 3, respectively. The glass material 3 is heated and softened to a viscosity that can be molded in a state where the central part (thick part) is lower than the peripheral part (thin part).

Next, the transfer arm 5 is moved toward the molding chamber section 6, and the seventh
Transfer plate 1 held on transfer arm 5 as shown in Figure a
Stop control is performed when the axial center of the mold 4 coincides with the axial center of the upper mold 50 of the molding chamber 6.

Next, as shown in FIG. 7, the lower mold 61 is moved upward to move the conveying plate 14 upward from the conveying section 5.

During this upward movement, as shown in FIG. 7C, the contact surface portion 14d on the transfer tray 14 side comes into contact with the lower end surface 52a of the sleeve 52 of the upper mold 50 and stops.

Next, the upper mold 50 is moved downward via the air cylinder 52, and the glass material 3 is pressed against the conveying tray 14 to perform press molding. At this time, the upper die 50 moves from the position shown by the two-dot chain line to the position shown by the solid line in FIG. 7C.

When the molding process is completed, the upper mold 50 is moved upward as shown in FIG. 7d, and the lower mold 61 is moved downward. In this step, the transport tray 14 containing the molded optical element 3a is fitted and held in the fitting portion 23 of the transport arm 5.

Next, the transfer arm 5 is moved in the direction of arrow 22 as shown in FIG. 1, and when the transfer plate 14 reaches a position directly below the recovery tower 13, it is controlled to stop.

Next, the recovery shaft 26 is moved upward, and the transfer plate 14 containing the optical element 3a is accommodated in the recovery tower 13 through a process that is reverse to the process of taking out the transfer plate from the standby tower 12.

Next, after the collection shaft 26 is moved down, the transport arm 5 is moved until the fitting portion 23 of the transport arm 5 reaches a position directly below the standby tower 12, and then the transport arm 5 is controlled to stop.

Thereafter, the above steps are repeated to continuously mold the optical element 3a.

As explained above, the method for molding the optical element of this example is as follows:
After heating and softening the glass material 3 to forcibly create a temperature distribution inside the glass material 3, the glass material 3 is placed in a mold 50.6.
The temperature distribution is shown in FIGS. 8 and 9.

FIG. 8a shows the state in which the glass material 3 is heated and softened in the heating furnace 81, and is just before being transferred between the upper and lower molds 50, 61 with forced temperature distribution created by the action of the upper and lower temperature controllers 82, 83. is shown. That is, each point inside the glass material 3, that is, the surface center m of the glass material 3, and the center position ff in the radial direction and thickness direction.

and the temperature at the center position n in the thickness direction of the outer circumference is point m, 0
The points are heated to a high temperature in this order. 9th
The figure is a graph of the temperature T of the glass material 3 on the fir axis, and the time-dependent changes at points m, 0, and n, with time plotted on the horizontal axis, and time t0 indicates the above temperature state. . After that, when the glass material 3 is press-molded by the upper and lower molds 50 and 61, the temperature at the 0 point, which is the center position of the thick part of the glass material 3, is difficult to fall, but it is heated to a temperature lower than the n point in advance. Therefore, the temperature of the glass material 3 becomes approximately the same at point 11, which is the temperature T+ at which the flow at point n almost stops.

In addition, the temperature at point m decreases rapidly, but the temperature ↑1 and the upper and lower molds 5
Since the mold temperature T2 of 0.61 is close to the mold temperature T2, the temperature decreases slowly near the temperature T, and at the time T, the glass material 3 reaches the point where there is almost no temperature difference between the m point, the n point, and the 0 point. 8
It is cooled to the state shown by the isomixture lines in the figure. After that, even if the temperature of the glass material 3 is in the process of converging to the mold temperature T2, the flow inside the glass material 3 stops at T1.
Since the temperature distribution inside the glass material 3 at this point is small, sink marks are less likely to occur, and as shown in FIG. 8C, an optical element 3a with high optical precision is formed which is transferred into a desired shape.

Next, in order to compare with the molding method of this example, the temperature distribution of the glass material 3 in the conventional molding method, which is performed without forcibly creating a temperature distribution in the glass material 3, is shown in FIGS. 10 and 11. I will explain.

First, the glass material 3 is heated almost uniformly in a heating furnace,
As shown in FIG. 10a, no temperature distribution occurs, and points m, n, and 0 inside the glass material 3 are at a temperature T at time 10 (see FIG. 11). When the glass material 3 is press-molded using a mold, the glass material 3 is cooled. At this time, the temperature at point m drops rapidly, and then the temperature at point n drops with a slight delay. However, the temperature at point 0 does not fall easily, and at point 11, when point n reaches T, the temperature at point 0 is high and in a fluid state. The temperature distribution at this time is the first
It has an elliptical shape centered on the 0 point, as shown by the equimixture lines in Figure 0. After that, the temperature of the glass material 3 converges to T2, and the m point, 0 point, and n point become the same temperature, but the temperature at the 0 point falls with a delay and solidification is slow, so the center A sink mark will occur in the area.

(Second Embodiment) FIG. 12 is a sectional view showing essential parts of a molding apparatus for carrying out a second embodiment of the method for molding an optical element according to the present invention.

The feature of the method for molding an optical element of this embodiment is that the optical element is molded by pressing a glass material 87 in the shape of a concave lens, which is thin in the center and thick in the peripheral part. It is configured to cool the thick portion by bringing it into contact with (or very close to) the peripheral portion, thereby forcibly creating a temperature distribution in the glass material 87.

That is, the temperature control ring 88 is formed into a ring shape 88a that allows its tip to contact only the thick portion 87a of the glass material 87. Also, inside the temperature control ring 88, there is a temperature control tube 89 for controlling the temperature at the tip by flowing an inert gas such as N2 gas at a constant amount, similar to the temperature control tube 82a of the first embodiment. is provided. The temperature control ring 88 is arranged to be able to move up and down in the vertical direction of the glass material 87, and one temperature control ring is not shown because it has the same configuration as the temperature control ring 88 shown in the figure. be. Furthermore, the other configurations are the molded r! shown in the first diagram above. 11, and the method of molding the optical element is the same as that of the first embodiment, so a description thereof will be omitted.

According to this embodiment, the temperature control ring 88 forces the temperature of the thick portion 87a of the glass material 87 to be in a temperature distribution state lower than that of the thin portion. That is, FIG. 13a shows the above-mentioned temperature distribution state, and when the glass material 87 is heated and softened, the temperature around the thick part 87 is lower than the center part 87b and the thin part in the thickness direction of the glass material 87. heated to a state. After that, when this glass material 87 is press-molded using a molding die, the temperature of the thin wall portion decreases rapidly, so that the temperature distribution of the glass material 87 is almost uniform when the flow of the glass stops, as shown in FIG. 13. be converted into Therefore, no sink marks occur during the subsequent cooling process of the glass material 87, and as shown in FIG. 13C, an optical element 87c with crystal precision and transferred to a desired shape is formed.

FIG. 14 shows the temperature distribution of the glass material 87 in a conventional molding method that does not forcefully create a temperature distribution in the glass material 87. ) is pressed by a molding die, the temperature in the thin part 87a decreases quickly and the temperature in the thick part 87a decreases slowly, so as shown in FIG.
The center 87d of the interior is in a high temperature state. At this time, the thin wall part and the outer surface of the glass material 87 are solidified and are in a non-flowable state, but the inner center 87d of the thick inner part 87a is in a flowable state, so that the molding is completed while being cooled and the temperature distribution When the flowable inner center 87d shrinks, a sink mark is generated at the periphery of the optical element 87c as shown in FIG. 14C.

(Third Embodiment) FIG. 15 is a sectional view showing essential parts of a molding apparatus for carrying out a third embodiment of the method for molding an optical element according to the present invention.

The characteristics of the optical element molding method of this example are that the glass material 9
Cooling gas 92 is sprayed onto the thick part of glass material 9.
There is one that forcibly creates a temperature distribution at zero.

That is, a temperature control ring 91 for controlling the temperature of the glass material 90 is provided with a through hole 93 for conducting a cooling gas 92 such as N2 gas therein. Note that the temperature control ring 91 is arranged in the vertical direction of the glass material 90.

The rest of the structure is the same as that of the molding apparatus 1 shown in the first drawing, and the method for molding the optical element is also different from that of the glass material 9.
This embodiment is the same as the first embodiment except that a cooling gas is blown from the tip of the temperature control ring 91 into the glass material 90 to forcibly create a temperature distribution inside the glass material 90, so a description thereof will be omitted.

According to this embodiment, the same functions and effects as those of the first embodiment described above can be obtained.

(Fourth Embodiment) FIG. 16 shows the main parts of a molding apparatus for carrying out the fourth embodiment of the method for molding an optical element according to the present invention, FIG. 16a is a front view, and FIG. is a plan view.

The characteristics of the optical element molding method of this example are that the glass material 9
There is a method that forcibly creates a temperature distribution in the glass material by cutting off the heat from the heater of the heating furnace that is radiated to the P1 meat part of No. 5.

That is, a temperature control ring 96 for controlling the temperature of the glass material 95 is provided with a shielding plate 97 at its tip to block radiation from the heater of the heating furnace. Note that the temperature control shafts 96 are provided in the vertical direction of the glass material 95.

The rest of the structure is the same as that of the molding apparatus 1 shown in the first diagram above, and the method for molding the optical element is such that the heat from the heater is suppressed from increasing in temperature in the thick portion by the shielding plate 97 and transferred to the inside of the glass material 95. The second embodiment is the same as the first embodiment except that the temperature distribution is forcibly generated, so the explanation thereof will be omitted.

According to this embodiment, the same functions and effects as those of the first embodiment described above can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, by forcibly creating a temperature distribution in advance on the glass material before forming while it is being heated in a heating furnace, and by setting the thicker part to a lower temperature than the thinner part, it is possible to Since the temperature difference inside the glass material is reduced, the reversibility of the shape of the molding surface is improved even for optical elements with large diameters or large degrees of thickness change.In other words, reversal deterioration due to sink marks is eliminated, and the molding process is shortened. The molding can be completed on time.

A highly accurate, low-cost optical element can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a molding apparatus for carrying out the first embodiment of the optical element molding method according to the present invention, FIG. 2 is a longitudinal sectional view of the main parts of FIG. 1, and FIG. A plan view showing the driving part of the transport arm of the device, an explanatory diagram of the process of molding the fourth mouth element, FIGS. 8 and 9 are explanatory diagrams and graphs showing the temperature distribution inside the glass material, and FIG. 10 and FIG. 11 are explanatory diagrams and graphs showing the temperature distribution inside the glass material in the conventional molding method, and FIG. 12 is a diagram of a molding apparatus for carrying out the second embodiment of the method for molding an optical element according to the present invention. A vertical cross-sectional view of the main parts, FIG. 13 is an explanatory diagram showing the temperature distribution inside the glass material, FIG. 14 is an explanatory diagram showing the temperature distribution inside the glass material in the conventional molding method, and FIG. 15 is an explanatory diagram showing the temperature distribution inside the glass material according to the present invention. FIG. 16 is a vertical cross-sectional view of a main part of a molding apparatus for implementing the third embodiment of the optical element molding method, and FIG. 16 is a molding apparatus for implementing the fourth embodiment of the optical element molding method according to the present invention. Figures 16a and 16b are front views, top views, and 17th
Figures a, b, c and Fig. 18 are explanatory diagrams and graphs showing the temperature distribution inside the glass material in the prior art. 3...Glass material 81...Heating furnace 82...Upper temperature control rod 83...Lower temperature control patent applicant Olympus Optical Industry Co., Ltd. Figure 7 (c) Figure 7 (b) Figure 12 Figure 13 Questions Figure 17 January 13, 1989 Patent Application No. 285355, 1988 2. Name of the invention Method for molding optical elements 3. Person making the amendment Relationship to the case Patent applicant Address: 2-43-2 Hatagaya, Shibuya-ku, Tokyo Name:
(037) Representative of Olympus Optical Industry Co., Ltd.
Toshi Yamabe 4, Agent 105 Address 6, 2-2-15 Hamamatsucho, Minato-ku, Tokyo Drawing subject to amendment 7 Contents of amendment (1) In the drawings, Figure 8 a, b Figure 10 a, Figure 13a. Figure 10

Claims (1)

[Claims] (1) In an optical element molding method in which a glass material is heated and softened and then press-molded using a molding die, when the glass material is heated and softened, the thinner part of the glass material is heated to a higher temperature than the thicker part. A method for molding an optical element, characterized by heating it to a temperature of .