JP2008013392A - Method for manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical element which can reduce the amount of the deviation of the optical axes of two optical surfaces of the optical element and the amount of the deviation between the center axis of the standard surface for assembling that is formed on the side of the outer periphery of the optical element and the optical axes of the optical surfaces, without narrowing the choices of the materials of a forming mold and without needing high processing accuracy in vain. <P>SOLUTION: In a method for manufacturing an optical element which includes a step of heating a forming mold that is provided with a first transfer member, a second transfer member and a barrel type member, a step of supplying a glass material, and a step of pressing the glass material, the method comprises press-molding the glass material in a state where the temperature of the barrel type member is lower than the temperature of the second transfer member and the barrel type member and the second transfer member are closely contacted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an optical element that obtains an optical element by pressure-molding a glass material with a molding die.

  Today, glass optical elements are widely used as lenses for digital cameras, optical pickup lenses such as DVDs, camera lenses for mobile phones, and coupling lenses for optical communication.

  Such glass optical elements are often manufactured by a press molding method in which a heated and softened glass material is pressure-molded with a molding die. As a press molding method for a glass optical element, (1) a molding glass material having a predetermined mass and shape is prepared in advance, the molding glass material is heated together with a molding die to a temperature at which the glass can be deformed, and then molded. A method of pressure-molding a glass material in a molding die and transferring the optical surface to the glass molding, or (2) heating the molding die to a predetermined temperature in advance, and then melting glass on the surface of the molding die A method is known in which a drop is dropped and the optical surface is transferred by pressure molding with a molding die while the dropped glass material is still at a deformable temperature.

  On the other hand, with the recent miniaturization and high precision of various optical devices, the performance required for glass optical elements is also increasing, and the optical axis misalignment between the two optical surfaces formed on the optical elements ( Hereinafter, it is referred to as “the amount of decentering between surfaces”) and the amount of deviation between the central axis of the assembly reference surface formed on the outer peripheral side surface of the optical element and the optical axis of the optical surface (hereinafter referred to as “the amount of eccentricity of the outer periphery”). With regard to the above, higher accuracy has been demanded. For this reason, studies have been made on methods for producing optical elements that can sufficiently reduce the amount of eccentricity between the surfaces and the amount of eccentricity of the outer periphery.

  As a method of manufacturing an optical element for reducing the amount of eccentricity between the surfaces and the amount of eccentricity of the outer periphery, a molding method using a mold that focuses on the thermal expansion coefficient of the material has been proposed (for example, see Patent Document 1).

  A method for molding such an optical element will be described with reference to FIG. FIG. 8 is a view showing a cross section of a molding die used in the method of molding an optical element described in Patent Document 1 and the molded optical element. This mold comprises a sliding mold 1, a non-sliding mold 2, and a body mold 3. The sliding mold 1 has a coefficient of thermal expansion α1, a non-sliding mold 2 has a coefficient of thermal expansion α2, When the coefficient of thermal expansion of the mold 3 is α3, the material of each member is selected so that α2> α1 ≧ α3.

The dimensions are set so that the clearance between the non-sliding mold 2 and the body mold 3 is substantially zero by expansion due to heating up to the molding temperature. The dimensions are set so that the clearance between the sliding mold 1 and the body mold 3 remains slidable. By molding the glass material using the molding die in which the coefficient of thermal expansion and the dimensions of each member are set in this way, it becomes possible to reduce the amount of eccentricity between the surfaces of the optical element to be molded and the amount of eccentricity of the outer periphery. .
JP 2005-231933 A

  However, the material of the molding die for press-molding the glass optical element is difficult to react with glass at high temperature, difficult to oxidize, obtain a mirror surface, good workability, hard, not brittle It is necessary to satisfy many conditions. The materials that actually satisfy these various conditions are limited to some ceramic materials including tungsten carbide and silicon carbide, special heat-resistant alloys, and the like. It has been difficult to select a material that satisfies the relationship of expansion coefficient.

  Further, even when a material satisfying the above relationship of the thermal expansion coefficient can be selected, the difference in the thermal expansion coefficient of each member cannot be set sufficiently large. In order to set the dimensions so that the clearance of the mold 3 is substantially zero, there is a problem that extremely high processing accuracy is required.

  The present invention has been made in view of the technical problems as described above, and the object of the present invention is to reduce the choice of material for the molding die and to avoid the need for high processing accuracy. An object of the present invention is to provide a method of manufacturing an optical element that can reduce the amount of eccentricity and the amount of eccentricity of the outer periphery.

  In order to solve the above problems, the present invention has the following features.

  1. A first transfer member having a first transfer surface for forming a first optical surface of the optical element; and a first transfer member disposed opposite the first transfer member to form a second optical surface of the optical element. A heating step of heating a molding die having a second transfer surface having a second transfer surface and a body mold member into which the first transfer member and the second transfer member are inserted during molding to a predetermined temperature; In the method of manufacturing an optical element, comprising: a glass material supply step for supplying a glass material to the molding die; and a pressure step for pressure-molding the glass material with the molding die. The first transfer member is slid within the barrel member in a state where the temperature of the barrel member is lower than that of the second transfer member and the barrel member and the second transfer member are in close contact with each other. Light that is a process of pressing and molding glass material Manufacturing method for the device.

  2. 2. The method of manufacturing an optical element according to 1, wherein the material of the second transfer member and the material of the body member are the same.

  3. A first transfer member having a first transfer surface for forming a first optical surface of the optical element; and a first transfer member disposed opposite the first transfer member to form a second optical surface of the optical element. A second transfer member having a second transfer surface; a side transfer member having a side transfer surface into which the second transfer member is inserted and forming at least a part of an outer peripheral side surface of the optical element; A heating step of heating a molding die provided with a predetermined temperature, a glass material supply step of supplying a glass material to the molding die, and a pressing step of press-molding the glass material with the molding die In the method of manufacturing an optical element, the pressurizing step causes the temperature of the side surface transfer member to be lower than the temperature of the second transfer member so that the side surface transfer member and the second transfer member are in close contact with each other. In this process, the glass material is pressed under pressure. The method of manufacturing an optical element, characterized in that.

  4). 4. The method of manufacturing an optical element according to 3, wherein the material of the second transfer member and the material of the side surface transfer member are the same.

  5. A step of taking out the optical element obtained in the pressing step from the molding die, and the temperature of the side surface transfer member in the taking step is higher than the temperature of the side surface transfer member in the pressing step. 5. The method for producing an optical element according to 3 or 4, which is high.

  According to the method for manufacturing an optical element of the present invention, the temperature of the body mold member is made lower than the temperature of the second transfer member, and the expansion amount of the both is differentiated by heating, whereby the body mold member and the second transfer member are made. Since the glass material is pressed in a state in which the member is in close contact with each other, the positional deviation between the first transfer member and the second transfer member inserted into the barrel member can be minimized, so that the molding die material The amount of optical axis misalignment between the two optical surfaces of the optical element can be reduced without narrowing the options and without requiring high processing accuracy.

  According to another method for manufacturing an optical element of the present invention, the temperature of the side surface transfer member is made lower than the temperature of the second transfer member, and the expansion amount of both is differentiated by heating. Since the glass material is pressed in a state where the second transfer member and the second transfer member are in close contact with each other, the selection of the material for the molding die is not narrowed, and the high-precision processing is not required. The amount of deviation between the central axis of the assembly reference surface to be formed and the optical axis of the optical surface can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
First, the molding die used for the manufacturing method of the optical element which is the 1st Embodiment of this invention is demonstrated. FIG. 1 is a cross-sectional view of a molding die used in the present embodiment, and shows a state where a glass material is being pressed in a pressing step.

  The molding die 10 used in this embodiment includes an upper mold 11 that is a first transfer member, a lower mold 12 that is a second transfer member, and a body mold member 13. The upper mold 11 has a first transfer surface 14 for forming a first optical surface of the optical element 17, and is moved downward by an air cylinder (not shown) while being inserted into the body mold member 13. The optical element 17 is pressurized. The lower mold 12 has a second transfer surface 15 for forming a second optical surface of the optical element 17, and is disposed facing the upper mold 11 while being inserted into the body mold member 13. The body mold member 13 has a function of aligning the positions of the upper mold 11 and the lower mold 12 to be inserted, and a function as a side surface transfer member having a side surface transfer surface 16 for forming the outer peripheral side surface of the optical element 17. Have both.

  The upper mold 11, the lower mold 12, and the body mold member 13 each have a heater 41 and a temperature sensor 42. The heater 41 and the temperature sensor 42 are connected to a temperature adjusting device 43, and the temperature of each member can be adjusted independently. In this embodiment, a cartridge heater that is used by being embedded in the member is used as the heater 41. However, if the upper die 11, the lower die 12, and the body die member 13 can be heated, this can be used. It is not limited to. For example, a sheet-like heater that is used in contact with the outside of the member may be used. Further, as the temperature sensor 42, known means such as a platinum resistance thermometer and various thermistors can be appropriately selected and used in addition to various thermocouples.

The upper mold 11, the lower mold 12, and the body mold member 13 are made of a superhard material mainly composed of tungsten carbide, a molding metal for press-molding a glass optical element such as silicon carbide, silicon nitride, and aluminum nitride. It can be appropriately selected from materials known as molds according to the intended use. Moreover, what formed protective films, such as various metals, ceramics, and carbon, on the surface of these materials can also be used. In the present invention, the temperature of the body mold member 13 in the pressurizing step is set lower than the temperature of the lower mold 12, and the lower mold 12 and the body mold member 13 are brought into close contact with each other by providing a difference in the amount of thermal expansion. The materials of the lower mold 12 and the body mold member 13 do not need to have different linear expansion coefficients, and can be made of the same material. In the present embodiment, as the material for the upper mold 11, the lower mold 12, and the body mold member 13, a superhard material mainly composed of tungsten carbide is used. The average linear expansion coefficient of the used superhard material from 0 ° C. to 600 ° C. is 6.2 × 10 ⁻⁶ / ° C.

  As for the size of the fitting portion of the lower mold 12 and the barrel mold member 13, there is a clearance necessary for setting at room temperature, and the lower mold 12 and the barrel mold member 13 are in close contact with each other by thermal expansion at the temperature in the pressurizing process. Set to. Here, at room temperature (25 ° C.), the outer diameter of the lower mold 12 was 20 mm, and the inner diameter of the body member 13 was 20.005 mm. Therefore, at room temperature (25 ° C.), there is a clearance of 2.5 μm on one side between the lower mold 12 and the body mold member 13, and it can be easily set.

  Generally, the amount of thermal expansion is calculated by the product of the linear expansion coefficient, the temperature difference, and the outer diameter. When calculated from the outer diameter of the lower mold 12 and the linear expansion coefficient, the clearance decreases by about 0.6 μm on one side every time the temperature of the lower mold 12 is increased by 10 ° C. from the temperature of the body mold member 13. Therefore, the clearance is reduced to 0 by lowering the temperature of the body mold member 13 by about 40 ° C. or more than the temperature of the lower mold 12, and the lower mold 12 and the body mold member 13 can be brought into close contact with each other.

  On the other hand, between the upper mold | type 11 and the trunk | drum mold member 13, the clearance of the grade which can be slid in a pressurization process is required. Here, the outer diameter of the upper mold 11 is set to a diameter of 19.99 mm and the inner diameter of the body mold member 13 is set to a diameter of 20 mm at room temperature (25 ° C.). Since the upper mold 11 and the body mold member 13 are made of the same material, the clearance amount hardly changes even at the temperature during pressurization in the pressurization process. Therefore, the clearance amount in the pressurizing step is 0.005 mm on one side, and it can slide well, and at the same time, the positional deviation between the upper mold 11 and the barrel mold member 13 can be suppressed to 0.005 mm or less.

  Next, the process of the manufacturing method of the optical element in this embodiment will be described. In FIG. 2, the process of the manufacturing method of the optical element in this embodiment is shown. Here, T 12 is the temperature of the lower mold 12, and T 13 is the temperature of the body mold member 13. Further, T13 (S103) is the temperature of the barrel member 13 in the pressurizing step S103, and T13 (S105) is the temperature of the barrel member 13 in the extracting step S105.

  The heating step S101 is a step of heating the molding die to a predetermined temperature. Of the molding die 10, the upper die 11 and the lower die 12 may be selected at a temperature within a range where the optical surface can be satisfactorily transferred to the glass material. In general, if the temperature of the upper mold 11 and the lower mold 12 is too low, it becomes difficult to transfer the optical surface to the glass material satisfactorily. On the contrary, it is not preferable to raise the temperature more than necessary from the viewpoint of preventing fusion between the glass material and the mold and the life of the mold. In practice, the appropriate temperature depends on various conditions such as the glass material, shape, size, molding die material, protective film type, optical element shape, size, etc. Is preferred.

  The temperature T13 of the trunk mold member 13 is set lower than the temperature T12 of the lower mold 12. Due to the difference in thermal expansion due to the temperature difference between the body mold member 13 and the lower mold 12, the clearance between the lower mold 12 and the body mold member 13 that existed at room temperature disappears, and at a temperature at which they are in close contact with each other. I need it. As described above, by setting the temperature of the body mold member 13 to be lower by about 40 ° C. or more than the temperature of the lower mold 12, the clearance becomes 0, and the lower mold 12 and the body mold member 13 can be brought into close contact with each other. Here, the temperature of the body mold member 13 was set to be 50 ° C. lower than the temperature of the lower mold 12.

  The glass material supply step S102 is a step of supplying the glass material to the molding die. In the present embodiment, a glass material that has been heated in advance and in a softened state is supplied to a molding die that has been heated to a predetermined temperature in the heating step S101. The molten glass may be supplied by being dripped naturally from the tip of the nozzle, or after a predetermined amount of molten glass flowing out from the nozzle is accumulated, it may be supplied to the molding die. Further, a glass material having a predetermined mass once solidified can be heated and supplied in a softened state.

  In the present embodiment, the glass material supply step S102 is performed after the heating step S101. However, the present invention is not limited to this order. For example, the glass material supply step S102 may be performed prior to the heating step S101, or the glass material supply step S102 may be performed in the middle of heating the mold in the heating step S101.

  The pressurizing step S103 is a step of press-molding a glass material with a molding die. In the pressurizing step S103, the temperature T13 of the trunk mold member 13 is lower than the temperature T12 of the lower mold 12, and the lower mold 12 and the trunk mold member 13 are in close contact with each other. In this state, the upper die 11 is driven by an air cylinder (not shown) and is slid within the body die member 13 to press-mold the glass material for a predetermined time.

  Thus, the temperature T13 of the body mold member 13 in the pressurizing step S103 is set lower than the temperature T12 of the lower mold 12, and the lower mold 12 and the body mold member 13 are positioned in close contact with each other. The positional deviation between the upper mold 11 and the lower mold 12 inserted into the body mold member 13 can be minimized, and the optical axis deviation amount of the two optical surfaces of the optical element 17 can be reduced. Further, the amount of deviation between the central axis of the assembly reference surface of the optical element formed by the side surface transfer surface 16 of the body member 13 and the optical axis of the second optical surface formed by the second transfer surface of the lower mold 12. Can also be reduced.

  S104 is a step of raising the temperature of the body member 13. In order to facilitate the removal of the optical element 17 in the next removal step S105, the temperature of the body mold member 13 is raised more than that in the pressurization step S103.

  The extraction step S105 is a step of extracting the obtained optical element 17. After the pressurization step S103 is completed, when the upper mold 11 is raised to remove the insertion part into the barrel member 13 and the obtained optical element is taken out, the outer peripheral side surface of the optical element 17 and the side surface portion of the barrel member 13 The transfer surface 16 may be in close contact, making it difficult to remove the optical element 17. In that case, the temperature T13 (S103) of the trunk mold member 13 in the take-out process S105 is made higher than the temperature T13 (S103) of the trunk mold member 13 in the pressurization process S103, and the inner diameter of the trunk mold member 13 is expanded by thermal expansion. Thus, the close contact state is released and can be easily taken out. If the temperature to be raised is too low, it is difficult to obtain the effect. Conversely, if the temperature to be raised is too high, the temperature of the barrel member 13 is lowered again to the temperature at the pressurizing step S103 in the next step. The required time becomes longer, which is not preferable from the viewpoint of productivity. Although a preferable temperature varies depending on various conditions, the optical element 17 can be normally taken out with a temperature increase of about 5 ° C. to 50 ° C.

  S106 is a process of lowering the temperature of the trunk mold member 13 to the temperature T13 (S103) of the trunk mold member 13 in the pressurizing process S103. The optical element 17 can be continuously manufactured by repeating this process S106 again from glass raw material supply process S102, after temperature reduction is completed and this process is complete | finished.

  In addition, this invention may include another process other than the process of S101-S106. For example, an optical element inspection step may be provided after the pressurizing step S103, or a molding die cleaning step may be provided after the take-out step S105.

(Embodiment 2)
A method for manufacturing an optical element according to the second embodiment of the present invention will be described. FIG. 3 is a cross-sectional view of a molding die used in the present embodiment, and shows a state where a glass material is being pressed in the pressing step.

  The molding die 20 used in the present embodiment includes a first transfer surface 24 of the upper mold 21 that is a flat surface, and a side surface transfer member 23 having a side surface transfer surface 26 instead of the body member 13. Are the same as the molding die 10 used in the first embodiment except for.

The upper mold 21, the lower mold 12, and the side surface transfer member 23 have a heater 41 and a temperature sensor 42, respectively, as in the first embodiment. Further, the material of the upper mold 21 and the side surface transfer member 23 is made of a super hard material mainly composed of tungsten carbide as in the lower mold 12. The average linear expansion coefficient from 0 ° C. to 600 ° C. is 6.2 × 10 ⁻⁶ / ° C. The other members are all the same material as the molding die 10 used in the first embodiment. Further, the size of the fitting portion between the lower mold 12 and the side surface transfer member 23 is the same as the size of the fitting portion between the lower mold 12 and the barrel member 13 in the first embodiment.

  In the present embodiment, since the first transfer surface 24 of the upper mold 21 is a flat surface, the positional deviation between the upper mold 21 and the lower mold 12 is not necessarily minimized. Therefore, as shown in FIG. 3, the upper mold 21 is not inserted into the side surface transfer member 23 even in the pressing step.

  A sectional view of the optical element 27 obtained in the present embodiment is shown in FIG. The optical element 27 has a side surface in addition to the first optical surface 51 obtained by the transfer of the first transfer surface 24 of the upper mold 21 and the second optical surface 52 obtained by the transfer of the second transfer surface 15 of the lower mold 12. The outer peripheral side surface 53 is obtained by transferring the side surface transfer surface 26 of the partial transfer member 23. The outer peripheral side surface portion 53 can be used as an assembly reference surface for the optical element 25. In the present invention, the region that can be used as the assembly reference surface is not limited to the case where it is formed over the entire area in the thickness direction of the outer peripheral side surface portion of the optical element, and as shown in FIG. It is only necessary that a region 54 that can be used as an assembly reference surface is formed on at least a part of the outer peripheral side surface portion 55.

  The steps of the method for manufacturing an optical element in this embodiment are shown in FIG. The steps are the same as those in the first embodiment shown in FIG. 2 except that the side surface transfer member 23 is used instead of the body member 13. Here, T 12 is the temperature of the lower mold 12, and T 23 is the temperature of the side surface transfer member 23. Further, T23 (S103) is the temperature of the side surface transfer member 23 in the pressurizing step S103, and T23 (S105) is the temperature of the side surface portion transfer member 23 in the take-out step S105.

  In the present embodiment, the temperature of the side surface transfer member 23 in the pressurizing step S103 is set lower than the temperature of the lower mold 12, and the lower mold 12 and the side surface transfer member 23 are positioned in close contact with each other. Therefore, the amount of deviation between the center axis of the assembly reference surface formed on the outer peripheral side surface portion of the optical element 17 and the optical axis of the second optical surface 52 can be reduced.

  Further, in the extraction step S105, the temperature T23 (S103) of the side surface transfer member 23 in the extraction step S105 is set higher than the temperature T23 (S103) of the side surface transfer member 23 in the pressurization step S103. Since the inner diameter of the side surface transfer member 23 is increased, the optical element 27 can be easily taken out.

(Embodiment 3)
A method for manufacturing an optical element according to the third embodiment of the present invention will be described. FIG. 6 is a cross-sectional view of a molding die used in the present embodiment, and shows a state where a glass material is being pressed in the pressing step.

  The molding die 30 used in this embodiment includes a lower mold 32 that is a first transfer member, an upper mold 31 that is a second transfer member, and a body mold member 33. The upper mold 31 has a second transfer surface 35 for forming a second optical surface of the optical element 37, and is moved downward by an air cylinder (not shown) while being inserted and fixed in the body mold member 33. Then, the optical element 35 is pressurized. The lower mold 32 has a first transfer surface 34 for forming a first optical surface of the optical element 35, and is disposed to face the upper mold 31. Is inserted into the body member 33.

  Unlike the case of the first embodiment, the body member 33 does not have a side surface transfer surface for forming the outer peripheral side surface portion of the optical element 35, and the outer peripheral side surface of the optical element 35 even when molding is completed. The part does not come into contact with the body member 33.

  The upper mold 31, the lower mold 32, and the body mold member 33 each include a heater 41 and a temperature sensor 42. The heater 41 and the temperature sensor 42 are connected to a temperature adjusting device 43, and the temperature of each member can be adjusted independently. In the present embodiment, an embedded cartridge heater is used for the upper mold 31 and the lower mold 32, and a sheet-like heater that is used in contact with the outside is used for the body mold member 33.

In the present embodiment, silicon carbide is used for the materials of the upper mold 31, the lower mold 32, and the trunk mold member 33. In order to bring the upper die 31 and the barrel member 33 into close contact with each other by setting the temperature of the barrel member 33 in the pressurizing step lower than the temperature of the upper die 31 and providing a difference in thermal expansion amount, It is not necessary to change the linear expansion coefficient of the material of the trunk-shaped member 33, and it can be composed of the same material. The silicon carbide used has an average coefficient of linear expansion of 4.6 × 10 ⁻⁶ / ° C. from 0 ° C. to 600 ° C.

  As for the size of the fitting portion between the upper die 31 and the barrel member 33, there is a clearance necessary for setting at room temperature, and the upper die 31 and the barrel member 33 are in close contact with each other due to thermal expansion at the temperature in the pressurizing step. Set to. Here, at room temperature (25 ° C.), the outer diameter of the upper mold 31 was 30 mm, and the inner diameter of the body mold member 33 was 30.004 mm. Therefore, at room temperature (25 ° C.), there is a clearance of 2 μm on one side between the upper mold 31 and the barrel mold member 33, and it is possible to set easily.

  When the amount of thermal expansion is calculated in the same manner as in the first embodiment, the clearance decreases by about 0.7 μm on one side each time the temperature of the upper mold 31 is increased by 10 ° C. from the temperature of the body mold member 33. Therefore, the clearance is reduced to 0 by lowering the temperature of the body mold member 13 by about 30 ° C. or more than the temperature of the lower mold 12, and the lower mold 12 and the body mold member 13 can be brought into close contact with each other.

  On the other hand, a clearance is required between the lower mold 32 and the body mold member 33 so as to be slidable in the pressurizing process. Here, at room temperature (25 ° C.), the outer diameter of the lower mold 32 is set to 39.99 mm, and the inner diameter of the body member 33 is set to 40 mm. Since the lower mold 32 and the body mold member 33 are made of the same material, the clearance amount hardly changes even at the temperature at the time of pressurization in the pressurization process. Therefore, the clearance amount in the pressurizing step is 0.005 mm on one side, and it can slide well, and at the same time, the positional deviation between the upper mold 11 and the barrel mold member 13 can be suppressed to 0.005 mm or less.

  Next, the process of the manufacturing method of the optical element in this embodiment will be described. In FIG. 7, the process of the manufacturing method of the optical element in this embodiment is shown. Here, T31 is the temperature of the upper mold 31, and T33 is the temperature of the body mold member 33.

  Glass material supply process S201 is a process of supplying a glass material to a molding die. In this embodiment, a glass material having a predetermined mass and shape prepared in advance is supplied at room temperature. At this time, the glass material is supplied in a state where the temperature of the molding die is also room temperature, and in the next heating step S202, it may be heated to a predetermined temperature required for pressurization, or the molding die may be preliminarily used. After heating to a predetermined temperature, the glass material may be supplied. Further, the glass material may be supplied at a temperature in the middle of heating to a predetermined temperature, and then heated to the predetermined temperature.

  The heating step S202 is a step of heating the molding die and the glass material to a predetermined temperature necessary for pressurization. As described above, the order of the glass material supply step S201 and the heating step S202 is not limited to this. As in the case of the first embodiment, since an appropriate temperature is affected by various conditions, it is preferable to obtain it experimentally in advance. Although the glass material is not in direct contact with the heater, it is in contact with the molding die and receives heat from the molding die and is heated to a predetermined temperature.

  The pressurizing step S203 is a step of press-molding a glass material with a molding die. In the pressurizing step S203, the temperature T33 of the trunk mold member 33 is lower than the temperature T31 of the upper mold 31 and the upper mold 31 and the trunk mold member 33 are in close contact with each other. In this state, the upper mold 31 is driven downward by an air cylinder (not shown), the lower mold 32 is inserted into the body mold member 33, and the glass material is pressed by the upper mold 31 and the lower mold 32 for a predetermined time. Mold.

  As described above, the temperature T33 of the body mold member 33 in the pressurizing step S203 is set lower than the temperature T31 of the upper mold 31, and the upper mold 31 and the body mold member 33 are positioned in close contact. The positional deviation between the upper mold 31 and the lower mold 32 inserted into the body mold member 33 can be minimized, and the amount of optical axis deviation between the two optical surfaces of the optical element 37 can be reduced.

  S204 is a step of cooling the molding die. The molding die is cooled until the temperature at which the optical element 37 formed in the pressing step S203 is sufficiently solidified.

  The taking-out step S205 is a step of taking out the solidified optical element 37 from the molding die. After the molding die is cooled in S204, the upper die 31 and the barrel member 33 are driven upward, and the optical element 37 remaining on the lower die 32 is taken out and collected by an adsorption device or the like. After this process is completed, the optical element 37 can be continuously manufactured by repeating the glass material supply process S201 to the process S205 again.

Sectional drawing of the molding die used in the first embodiment The figure which shows the process of the manufacturing method of the optical element in 1st Embodiment. Sectional view of a molding die used in the second embodiment Sectional drawing of the optical element obtained in 2nd Embodiment The figure which shows the process of the manufacturing method of the optical element in 2nd Embodiment. Sectional drawing of the molding die used in 3rd Embodiment The figure which shows the process of the manufacturing method of the optical element in 3rd Embodiment. Sectional view of a molding die used in a conventional manufacturing method

Explanation of symbols

11, 21, 31 Upper mold 12, 32 Lower mold 13, 33 Body member 14, 24, 34 First transfer surface 15, 35 Second transfer surface 16, 26 Side surface transfer surface 17, 27, 37 Optical element 23 Side surface Part transfer member 41 Heater 42 Temperature sensor 43 Temperature control device

Claims (5)

A first transfer member having a first transfer surface for forming a first optical surface of the optical element; and a first transfer member disposed opposite the first transfer member to form a second optical surface of the optical element. A heating step of heating a molding die having a second transfer surface having a second transfer surface and a body mold member into which the first transfer member and the second transfer member are inserted during molding to a predetermined temperature; ,
A glass material supply step of supplying a glass material to the molding die;
In the method of manufacturing an optical element having a pressurizing step of press-molding the glass material with the molding die,
In the pressurizing step, the temperature of the drum mold member is made lower than the temperature of the second transfer member, and the first transfer member is placed in a state where the drum mold member and the second transfer member are in close contact with each other. A method for producing an optical element, comprising: a step of pressure-molding a glass material by sliding in a body-shaped member. 2. The method of manufacturing an optical element according to claim 1, wherein a material of the second transfer member and a material of the body member are the same. A first transfer member having a first transfer surface for forming a first optical surface of the optical element; and a first transfer member disposed opposite the first transfer member to form a second optical surface of the optical element. A second transfer member having a second transfer surface; a side transfer member having a side transfer surface into which the second transfer member is inserted and forming at least a part of an outer peripheral side surface of the optical element; A heating step of heating a molding die provided with a predetermined temperature;
A glass material supply step of supplying a glass material to the molding die;
In the method of manufacturing an optical element having a pressurizing step of press-molding the glass material with the molding die,
In the pressing step, the glass material is pressed in a state where the temperature of the side surface transfer member is lower than the temperature of the second transfer member and the side surface transfer member and the second transfer member are in close contact with each other. A method of manufacturing an optical element, which is a molding step. 4. The method of manufacturing an optical element according to claim 3, wherein the material of the second transfer member is the same as the material of the side surface transfer member. A step of taking out the optical element obtained in the pressing step from the molding die;
5. The method of manufacturing an optical element according to claim 3, wherein the temperature of the side surface transfer member in the extraction step is higher than the temperature of the side surface transfer member in the pressurization step.

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