JP2007153658A - Apparatus for molding optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element-molding apparatus capable of stably producing an optical element having high accuracy with respect to its profile as well as surface by improving a molding die so that heat affection such as heating and cooling does not have influence on the side of its portion fastening a mold-mounting plate. <P>SOLUTION: The optical element-molding apparatus has a pair of upper and lower molding dies 2 and 3, each of which is formed into an integration type structure to produce the optical element such as glass lenses by press-molding a glass material 18 softened by heating, and is provided integrally with the fastening parts 8 and 9 which are fastened to the mold-mounting plates 4 and 5 of the molding apparatus 1 by a plurality of bolts 6. Further in the molding dies 2 and 3, the lengths L1 and L2 from the molding faces 10 and 11 to the fastening parts 8 and 9, respectively are set up so that the heat affection does not have influence on the fastening parts 8 and 9 when the molding faces 10 and 11 on the respective end sides of the molding dies are heated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical element molding apparatus, and in particular, a heat-softened optical element material using a pair of molding dies having a precisely shaped molding surface based on the shape of the optical element to be obtained. The present invention relates to a molding apparatus used for producing an optical element such as a glass lens by pressurization (press molding) at a predetermined pressure.

After the heated and softened optical element material is carried between the upper mold and the lower mold, which are a pair of molds, by pressing the upper mold and the lower mold with a predetermined pressure (press molding), A molding apparatus for manufacturing an optical element that requires high shape accuracy and surface accuracy such as a glass lens, a prism, and a diffraction grating is known (for example, see Patent Document 1).
Incidentally, the molding die used in the molding apparatus described in Patent Document 1 is a barrel die having a through-hole penetrating vertically, and a mold that is slidably inserted into the through-hole of the barrel die from above and below. It consists of an upper mold and a lower mold that are clamped (mold matching).

  The molding surfaces of the upper mold and the lower mold used in the molding apparatus for manufacturing such an optical element are high by being subjected to precise shape processing based on the shape of the optical element to be obtained. An optical element having a shape accuracy and a surface accuracy is formed. In other words, in press molding, the upper mold and the lower mold are clamped at a predetermined pressure, so that the molding surfaces of the upper mold and the lower mold are the surfaces of the optical element material (optical function) carried between the two molds. Surface).

Also, in recent years, not only aspherical lenses but also prisms and other various optical elements can be obtained by one-time molding by press molding that eliminates polishing finishing (post-finishing), which requires complicated and time-consuming processes. Attempts have been made to manufacture. For that purpose, as described above, the molding surfaces of the upper mold and the lower mold are processed with high precision into a precise shape based on the shape of the optical element to be manufactured, and the upper mold and the lower mold are formed. The centering (centering) accuracy of matching the mold cores with high accuracy is very important.
Japanese Patent Laid-Open No. 7-215721 (paragraph numbers 0011 to 0012, see FIG. 1)

  By the way, in order to match the cores of the upper mold and the lower mold with high accuracy using the barrel mold as in the mold of the conventional molding apparatus described above, the upper mold, the lower mold, and the trunk mold Clearance should be as small as possible. However, if the clearance is reduced in this way, it is expected that it will be difficult for the upper mold and the lower mold to slide smoothly with respect to the body mold.

Therefore, as shown in FIG. 2, the molding apparatus is configured by attaching the upper and lower mounting plates 37 and 38 with the cores of the upper mold 32 and the lower mold 33 aligned, without using the body mold. It is also possible.
However, in the case of a molding apparatus that does not use a body mold as described above, there remains a problem that misalignment occurs in the mold cores of the upper mold 32 and the lower mold 33 due to thermal effects.
In other words, a mold for heating and softening optical element material between the upper mold and the lower mold, mainly into the molding surface of the lower mold, and press molding optical elements such as glass lenses by clamping both molds. The temperature is raised to a temperature suitable for press molding, for example, in the range of 400 to 700 ° C.
On the other hand, the mold temperature is cooled to a temperature at which the glass lens molded after press molding can be gradually cooled and taken out (temperature at which the molding surface is transferred to the surface of the optical element material), for example, in the range of 300 to 350 ° C. (Decool) is lowered.
For this purpose, for example, an upper mold and a lower mold formed of a mold material capable of induction heating, such as molybdenum alloy (Mo) and tungsten alloy (Wc), are subjected to expansion and contraction due to cooling every cycle (heating → Press molding (clamping) → cooling (removal cooling) → product removal (mold opening)) is repeated.

  Thus, in the case of a molding apparatus that does not use a body mold, misalignment (axial misalignment of the molding surface) occurs between the upper mold and the lower mold due to the thermal effects of heating and cooling repeated every cycle. There was a problem. This misalignment has had a great influence on the optical function of the optical element, and has been a factor in reducing the production yield. In other words, the optical axis of one optical functional surface of the glass lens to be manufactured and the optical axis of the other optical functional surface are displaced, and as a result, the lens performance is not stabilized under the influence of the axial displacement, There was a problem that the production yield was reduced.

  Incidentally, as shown in FIGS. 2 (a) and 2 (b), misalignment due to thermal influence is caused by the four corners of the fastening portions 34, 35 formed integrally with the upper mold 32 and the lower mold 33 being bolts 36 ... This is caused by variations in the fastening force (tightening force) at the four positions with respect to the upper and lower mounting plates 37 and 38 fastened by the above. The variation in the fastening force at the four locations is assumed to occur in the fastening operation when the upper die 32 and the lower die 33 are attached and set to the upper and lower attachment plates 37 and 38, respectively. At this time, a torque wrench is used, but it is very difficult to make the four bolting portions have a constant fastening force in view of the accuracy of the torque wrench.

Further, the flapping of the fastening force is caused by repeated expansion and contraction of the upper mold 32 and the lower mold 33 due to thermal effects.
In other words, the heat on the molding surfaces 39 and 40 of the upper mold 32 and the lower mold 33 heated and raised during press molding causes the fastening portions 34 and 35 of the upper mold 32 and the lower mold 33 to the upper and lower mounting plates 37 and 38. On the other hand, the heat on the molding surfaces 39 and 40 side of the upper mold 32 and the lower mold 33 that is cooled down when taking out the molded glass lens is conducted to the fastening portions 34 and 35 side. Is repeated.
As a result, the bolts 36 including the fastening portions 34 and 35 themselves are repeatedly expanded or contracted due to thermal influence (thermal cycle). In particular, since the bolts 36 are elongated due to the thermal effect when the molding surfaces 39 and 40 of the upper mold 32 and the lower mold 33 are heated and raised, the fastening force is reduced. And since the thermal influence which receives differs in four bolting parts, dispersion | fluctuation generate | occur | produces in the fastening force of four places.

  Therefore, for example, when variations in fastening force occur such that the fastening force at one or two of the four bolt fastening portions is lower than the fastening force of the other bolt fastening portions, the upper die 32 and the lower die 33 are generated. When the mold part expands or repeats expansion / contraction such as contraction from the expanded state, the mold part side including the fastening part where the fastening force is reduced has other bolting parts remaining without the fastening force being reduced. From the starting point, the expansion and contraction are repeatedly moved with a slight clearance depending on the bolts 36 and the bolt fastening holes 41 and 42 opened in the fastening portions 34 and 35. For this reason, misalignment occurs between the upper mold 32 and the lower mold 33.

  Therefore, in the present invention, the cause of misalignment occurring in the mold is expansion / contraction of the fastening part due to the thermal effect (thermal cycle) from the molding surface side on the fastening part side fastened to the mold mounting plate. In order to solve the above-mentioned problems, the mold has been improved so that heat effects such as heating and cooling do not reach the fastening part side with the mold mounting plate. It is an object of the present invention to provide an optical element molding apparatus capable of stably manufacturing an optical element having surface accuracy.

  In order to solve the above-described problems, the present invention provides, in claim 1, a molding apparatus for manufacturing an optical element by pressure-molding a heat-softened optical element material using a pair of molds, The pair of molding dies are integrally formed with a desired mold material, and integrally include a fastening portion fastened to the mold mounting plate by bolting, and the pair of molding dies that pressurize the optical element material. The length dimension from the molding surface of the pair of molding dies to the fastening portion is set so that the fastening portion does not receive the thermal influence when the molding surface is heated. .

According to the structure of Claim 1, the length from the shaping | molding surface to the fastening part fastened to a type | mold mounting plate is set so that it may not receive the heat influence when a shaping | molding surface is heated. Thereby, the thermal influence in a fastening part can be suppressed. That is, by suppressing the expansion / contraction of the fastening portion due to thermal influence (thermal cycle), it is possible to prevent misalignment when the pair of molds are clamped.
In addition, since the pair of molds has an integral structure, the mold structure is complicated, for example, a heat insulating material that suppresses heat conduction is interposed in the middle of the mold between the molding surface and the fastening portion. Without adopting, it is possible to suppress the thermal effect on the fastening portion and prevent misalignment of the pair of molds. Further, since the mold structure is simple, a pair of molds can be manufactured easily and at low cost.

In the present invention, the pair of molds are formed with hollow portions that open to the fastening portion side and reach the vicinity of the molding surface (Claim 2).
By comprising in this way, the heat transfer amount by the heat conduction to the fastening part side of the heat | fever when the shaping | molding surface of a pair of shaping | molding die is heated can be made small. In other words, the cavity acts as a heat insulating space that suppresses the amount of heat transferred to the fastening part, and the heat when the molding surfaces of the pair of molds are heated by this heat insulation acts to the fastening part. Therefore, the heat conduction can be effectively suppressed. Furthermore, the cooling efficiency can be improved by introducing the cooling gas into the cavity provided so as to reach the vicinity of the molding surface. In addition, since cooling can be performed from the inside of the mold that does not affect the molding surface, air cooling that is less expensive than nitrogen gas can be performed without considering the effect of oxidation.

In the present invention, the one end side portion where the molding surfaces of the pair of molding dies are formed is a small-diameter mold portion having a small cross-sectional area within a desired length range from the molding surfaces, and the fastening is performed from the small-diameter mold portion. The length range leading to the part is a large-diameter mold part having a cross-sectional area larger than that of the small-diameter mold part, and the cross-sectional area of the large-diameter mold part is formed larger than the cross-sectional area of the small-diameter mold part. 3).
By being comprised in this way, a molding surface can be heated up efficiently. In other words, the molding surface is formed on the small-diameter mold part that has a smaller cross-sectional area (in the mold thickness or mold width direction) than the large-diameter mold part attached to the mold mounting plate and has an increased heat transfer rate per unit time and unit area. By doing so, for example, the molding surface can be efficiently heated by the heating means disposed around the small-diameter mold portion. In addition, since the large-diameter mold part side having a larger cross-sectional area than the small-diameter mold part side is fastened to the mold mounting plate via a fastening part provided integrally with the large-diameter mold part, the mold mounting plate In contrast, the mold can be mounted and set stably.

In the present invention, the mold mounting plate is provided with a cooling means.
By being configured in this way, the cooling of the mold mounting plate by the cooling means is transferred by heat conduction to the fastening part side of the pair of molding dies in surface contact with the mold mounting plate. Thereby, the mold mounting plate and the fastening portion are always kept at the same temperature state. That is, it can be expected to more effectively suppress the thermal influence of the fastening portion when the molding surface is heated.

  The optical element molding apparatus according to the present invention is configured as described above, so that the upper mold and the lower mold are affected by heat when the upper and lower molding surfaces are heated. Misalignment can be suppressed. Thereby, an optical element having high shape accuracy and surface accuracy can be stably manufactured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
1A and 1B show an embodiment of an optical element molding apparatus according to the present invention, in which FIG. 1A is a cross-sectional view schematically showing main parts constituting the molding apparatus, and FIG. It is the figure which looked at the type | mold from the molding surface side.

≪Description of molding equipment≫
As shown in FIG. 1, the molding apparatus 1 includes a movable-side upper mold 2 and a fixed-side lower mold 3 that form a pair of molding dies. The upper mold 2 and the lower mold 3 are respectively provided with respective mold mounting plates (hereinafter, the upper mold is referred to as “upper mounting plate” and the lower mold is referred to as “lower mounting plate”) 4, 5. Are formed so as to be opposed to each other on the same vertical axis.

Further, the molding apparatus 1 includes a movable shaft (press shaft) 7 on the movable upper mounting plate 4. By moving the upper mold 2 in the vertical direction by the movable shaft 7, press molding is performed in which the upper mold 2 is clamped to the lower mold 3 with a predetermined pressure, and a glass lens as an optical element is formed. After the molding, the mold is opened so that the upper mold 2 is separated from the lower mold 3 in order to take out the glass lens. The lower mounting plate 5 on the fixed side is fixed at a fixed position facing the upper mounting plate 4 (upper mold 2).
The movable shaft 7 is a cylinder rod of a mold clamping cylinder (not shown) that is driven by an operating medium such as hydraulic pressure or air, and the mold is clamped to the lower mold 3 and the upper mold is opened in the mold opening direction by driving the mold clamping cylinder. 2 is configured to move.

As shown in FIG. 1, the molding apparatus 1 includes heating means (a heater 16 described later) around the upper mold 2 and the lower mold 3. By this heating means, the molding surfaces 10 and 11 to be described later of the upper mold 2 and the lower mold 3 are heated up to a mold temperature suitable for press molding, for example, a range of 400 to 700 ° C.
In addition, the molding apparatus 1 includes a cooling means for the upper mounting plate 4 and the lower mounting plate 5. By cooling the upper mounting plate 4 and the lower mounting plate 5 together with the fastening portions 8 and 9 to be described later by the cooling means, the molding surfaces 10 and 11 of the upper die 2 and the lower die 3 are formed. When heated by the heating means, the temperature is not generated between the upper mounting plate 4 and the fastening portion 8 of the upper mold 2 and between the lower mounting plate 5 and the fastening portion 9 of the lower mold 3. Has been.

≪Explanation of upper mold and lower mold≫
The upper mold 2 and the lower mold 3 are formed in an integral structure by a desired mold material.
Here, the mold material may be a mold material that can be precisely shaped based on the shape of the glass lens to be obtained and has hardness and heat resistance that can withstand repeated pressing (press molding load). For example, there is no particular limitation. For example, from the viewpoint of obtaining extremely high surface accuracy (optical function surface) of a glass lens, ceramics such as silicon carbide (SiC) and silicon nitride (Si ₃ N ₄ ) can be mentioned.

As shown in FIG. 1, the upper die 2 and the lower die 3 are formed with molding surfaces 10 and 11 at opposite end surfaces, and fastening portions 8 and 9 are integrally formed around the other end side. ing.
The molding surfaces 10 and 11 are precisely shaped based on the shape of the glass lens to be obtained.
The fastening portions 8 and 9 are projected in a hook shape (flange shape) on the upper die 2 and the lower die 3 and, as shown in FIG. 1B, bolt fastening holes 12... Are respectively opened, and are formed so as to be fastened to the upper mounting plate 4 and the lower mounting plate 5 by bolts 6. At the time of this fastening, a washer 19 is interposed between the bolt 6 and the fastening portions 8 and 9. The washer 19 is made of stainless steel (SUS) or the like, and prevents loosening of the bolts 6.

Further, the upper mold 2 and the lower mold 3 are molded so that the fastening portions 8 and 9 are not affected by the heat when the molding surfaces 10 and 11 are heated by the heating means and cooled by the cooling means (not shown). Lengths L1 and L2 from the surfaces 10 and 11 to the fastening portions 8 and 9 are set.
Here, the lengths L1 and L2 of the upper mold 2 and the lower mold 3 are appropriately determined depending on the mold material. For example, the lengths L1 and L2 are set to the lengths in the case of a mold material capable of induction heating such as molybdenum alloy (Mo) and tungsten alloy (Wc) and the mold material not suitable for induction heating such as ceramics. A big difference comes out. That is, there is a great difference in the setting of the lengths L1 and L2 between a mold material having a high thermal conductivity and a mold material having a low thermal conductivity.

Further, as shown in FIG. 1, the upper mold 2 and the lower mold 3 have one end side portions where the molding surfaces 10, 11 are formed with a small diameter within a range of the desired lengths L3, L4 from the molding surfaces 10, 11. The range of length L5, L6 from this small diameter mold part 2a, 3a to the fastening parts 8 and 9 is made into large diameter mold part 2b, 3b.
Here, the small-diameter mold parts 2a and 3a mean that the cross-sectional area (in the mold thickness or mold width direction) when horizontally sectioned is smaller than the cross-sectional area on the large-diameter mold parts 2b and 3b side, The large-diameter mold parts 2b and 3b mean that the cross-sectional area when horizontally sectioned is larger than the cross-sectional area on the small-diameter mold parts 2a and 3a side, and the cross-sectional shape is circular (round). It does not mean the shape of being. Therefore, the cross-sectional shape of the small-diameter mold parts 2a and 3a and the large-diameter mold parts 2b and 3b when they are sectioned horizontally may be circular or square such as square or rectangular.

  Moreover, as shown in FIG. 1, the cavity parts 14 and 15 which opened the fastening parts 8 and 9 side are formed in the large diameter mold parts 2b and 3b of the upper mold | type 2 and the lower mold | type 3. As shown in FIG.

≪Description of hollow part≫
The cavities 14 and 15 are such that the heat of the molding surfaces 10 and 11 of the upper mold 2 and the lower mold 3 heated to a predetermined mold temperature by the heating means is from the small-diameter mold parts 2a and 3a to the large-diameter mold parts 2b and 3b side. It acts as a heat insulating space that cuts off the amount of heat when being conducted to the heat, and the heat of the molding surfaces 10, 11 is conducted to the fastening portions 8, 9 provided integrally with the large diameter mold portions 2b, 3b. It suppresses that.
As shown in FIG. 1, the hollow portion opens the fastening portions 8 and 9 side of the large-diameter mold portions 2b and 3b and is near the stepped boundary with the small-diameter mold portions 2a and 3a having the molding surfaces 10 and 11. It is formed in the large-diameter mold parts 2b and 3b so that the part becomes the bottom of the hole.

≪Explanation of heating means≫
The heating means is a heater 16 composed of an infrared lamp using electricity as a heat source, and is arranged around the small-diameter mold portions 2a and 3a of the upper mold 2 and the lower mold 3 at an appropriate interval as shown in FIG. The small-diameter mold portions 2a and 3a (molding surfaces 10 and 11) and the glass material 18 are formed so as to be heated up to a predetermined mold temperature suitable for press molding, for example, a range of 400 to 700 ° C.

≪Description of cooling means≫
The cooling means includes a temperature difference between the upper mounting plate 4 and the lower mounting plate 5 and the fastening portions 8 and 9 of the upper mold 2 and the lower mold 3 fastened to the upper and lower mounting plates 4 and 5 by bolts 6. It cools so that it may suppress.
This cooling means is provided in the upper mounting plate 4 and the lower mounting plate 5 by incorporating a cooling pipe or providing a cooling hole 17 in the surface direction of the upper mounting plate 4 and the lower mounting plate 5, such as water. The cooling medium is fed in by a forced circulation system.
The circulation flow rate and circulation flow rate of a cooling medium such as water can be arbitrarily adjusted by a cooling device (not shown). In other words, the upper mounting plate 4 and the lower mounting plate 5, the materials of the upper mold 2 and the lower mold 3, the material of the bolts 6 and the like can be arbitrarily adjusted according to different thermal conductivities.

  As shown in FIG. 1A, the upper mounting plate 4 and the lower mounting plate 5 are formed in the cavity portions 14 and 15 of the upper mold 2 and the lower mold 3, particularly in the hole bottoms of the cavity portions 14 and 15. Gas introduction holes 20 and 21 for introducing an inert gas such as air or nitrogen gas are provided respectively, and the small-diameter mold parts 2a and 3a (molding surfaces 10 and 11) are formed from the inside of the mold (the inside of the mold). Cooling. That is, the mold temperature is cooled down to a temperature at which the molded glass lens can be gradually cooled and taken out after press molding (temperature at which the molding surfaces 10 and 11 are transferred to the surface of the glass material 18), for example, in the range of 300 to 350 ° C. (To cool).

Next, in this embodiment, when the molding surfaces 10 and 11 of the upper mold 2 and the lower mold 3 are heated, the upper mold 2 and the upper mold 2 fastened to the upper mounting plate 4 and the lower mounting plate 5 by bolts 6. In order to investigate the thermal effect on the fastening portions 8 and 9 of the lower mold 3, tests were conducted based on the test conditions shown below.
Test conditions Upper and lower mold materials: Ceramics Upper and lower mold lengths L1, L2: 60 mm
Small diameter part length L3, L4: 20mm
Large diameter part length L5, L6: 40 mm
Molding surface heating temperature: 700 ° C
Upper mounting plate and lower mounting plate materials: Invar material (low expansion alloy)
Bolt material: Ambiloy material Test chamber temperature: 25 ° C (room temperature)
Here, the linear expansion coefficient of the ceramics used as the upper mold and the lower mold is 3.2 × 10 ⁻⁶ / (700 ° C.), and the linear expansion coefficient of the invar material used as the material of the upper mounting plate and the lower mounting plate. Is equivalent to ceramics at 100 ° C., and the linear expansion coefficient of the ambiloy material used as the bolt material is 5.6 × 10 ⁻⁶ / (700 ° C.). And, between the bolt and the fastening portion of the upper die and the lower die, a washer made of a stainless steel material (SUS) having a linear expansion coefficient larger than that of the ambiloy material is interposed to prevent loosening of the bolt. .

  Under such test conditions, the overheat-softened glass material 18 is carried into the molding surface 11 of the lower mold 3 (see FIG. 1A), and the upper mold 2 is moved down by the movable shaft 7 to a predetermined pressure. Then, press molding shots for clamping to the lower mold 3 were repeated. Then, it turned out that the thermal influence which acts on the fastening parts 8 and 9 of the upper mold | type 2 and the lower mold | type 3 is restrained to 100 degrees C or less. That is, it was proved from the test results that the heat conduction from the molding surfaces 10 and 11 heated to 700 ° C. to the fastening portions 8 and 9 was significantly suppressed. The temperature was measured by inserting a measuring instrument such as a thermocouple into the fastening portions 8 and 9 or the upper and lower mounting plates 4 and 5 or setting the surface.

According to the molding apparatus 1 of the present embodiment configured as described above, expansion of the fastening portions 8 and 9 due to thermal influence (thermal cycle) when the molding surfaces 10 and 11 of the upper mold 2 and the lower mold 3 are heated. -By suppressing the shrinkage, misalignment when the upper mold 2 is clamped with respect to the lower mold 3 can be prevented.
Further, since the upper mold 2 and the lower mold 3 have an integral structure, the mold structure is complicated, for example, a heat insulating material is interposed between the molding surfaces 10 and 11 and the fastening portions 8 and 9. Without adopting a technique that invites misalignment, the thermal effect on the fastening portions 8 and 9 can be suppressed, and misalignment between the upper mold 2 and the lower mold 3 can be reliably prevented. In addition to this, since the mold structure is simple, the upper mold 2 and the lower mold 3 can be easily manufactured and provided using the mold material made of ceramics such as silicon carbide and silicon nitride as described above. can do.
In addition, the amount of heat transferred by heat conduction to the fastening portions 8 and 9 when the molding surfaces 10 and 11 are heated can be reduced by the cavity portions 14 and 15 acting as heat insulating spaces. Thereby, the heat influence conducted to the fastening portions 8 and 9 can be more effectively suppressed.

The specific configuration of the embodiment of the present invention is not limited to the above-described embodiment, and there is a change in the design within the scope of the invention described in claims 1 to 4 without departing from the gist of the present invention. However, it is included in the present invention.
The upper mold 2 and the lower mold 3 are not limited to the stepped mold structure. For example, when the lengths L1 and L2 from the molding surfaces 10 and 11 to the fastening portions 8 and 9 are horizontally sectioned, A straight integrated structure having the same cross-sectional area (mold thickness or mold width direction) may be used. In this case, the cavities 14 and 15 are formed on the molding surface 10 in consideration of the hardness (rigidity) required for the molding surfaces 10 and 11 when the glass material 18 heated and softened is pressed at a predetermined pressure. , 11 up to the vicinity.
Further, the heating means is not limited to the infrared lamp, and a heater composed of an induction heating coil or the like can be used.

1 shows an embodiment of a molding apparatus for an optical element according to the present invention, (a) is a cross-sectional view schematically showing main parts constituting the molding apparatus, and (b) shows molding surfaces of an upper mold and a lower mold. It is the figure seen from the side. An example is shown in a conventional molding apparatus, (a) is a cross-sectional view schematically showing a main part composed of a trunk mold, an upper mold and a lower mold, and (b) is a molding surface side of the upper mold and the lower mold. It is the figure seen from.

Explanation of symbols

1 Molding device 2 Upper mold (molding mold)
3 Lower mold (molding mold)
4 Upper mounting plate (mold mounting plate)
5 Lower mounting plate (mold mounting plate)
6 Bolt 8, 9 Fastening part 10, 11 Molding surface 12, 13 Bolt fixing hole 14, 15 Hollow part 16 Heater (heating means)
17 Cooling hole (cooling means)

Claims (4)

A molding apparatus for producing an optical element by pressurizing a heat-softened optical element material using a pair of molding dies,
The pair of molds is integrally formed with a desired mold material and integrally includes a fastening portion fastened to the mold mounting plate by bolting,
And from the molding surface of the pair of molds to the fastening part, the thermal effect when the molding surfaces of the pair of molding dies that pressurize the optical element material are heated is not received by the fastening part. An apparatus for molding an optical element, characterized in that a length dimension is set.   2. The optical element molding apparatus according to claim 1, wherein the pair of molding dies is formed with a cavity that opens to the fastening portion side and extends to the vicinity of the molding surface. In the pair of molds, one end side portion where the molding surface is formed is a small-diameter mold part within a desired length range from the molding surface, and a length range from the small-diameter mold part to the fastening part is large-diameter. Mold part,
3. The optical element molding apparatus according to claim 1, wherein a cross-sectional area of the large-diameter mold portion is formed larger than a cross-sectional area of the small-diameter mold portion.   The optical element molding apparatus according to any one of claims 1 to 3, wherein the mold mounting plate includes a cooling unit.

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