JP5695518B2 - Optical element manufacturing method, optical element molding die set, and optical element manufacturing apparatus - Google Patents

Description

  The present invention relates to an optical element molding die set used for manufacturing an optical element, and an optical element manufacturing apparatus and manufacturing method for manufacturing an optical element.

In recent years, when an aspherical lens or the like is efficiently manufactured, a method of molding an optical element by heating and softening an optical element material, pressurizing with a pair of molds, and cooling is used.
Conventionally, when molding an optical element, an upper mold and a lower mold are fitted to a first body mold and used as a mold set, or the mold set is further fitted to a second body mold. There is known a technique of using as a mold set and molding an optical element material sandwiched between an upper mold and a lower mold (see, for example, Patent Document 1).

  When an optical element material is molded using a mold set having a body mold as described in Patent Document 1, a heating plate, a pressure plate (heating and pressing may be the same plate), and cooling, respectively. The mold sets are sequentially fed in synchronization with a molding process by a plurality of plates having a molding plate such as a plate without interruption.

  Also, after taking out the optical element molded from the mold set, the optical element material is again supplied between the upper and lower molds in the mold set, and the mold set is again introduced into the molding process to perform molding, that is, the same There is known a method using a circulation type molding technique for repeatedly feeding a set of molds.

  In addition, in the said patent document 1, in order to suppress heat conduction and to make it difficult to produce a temperature difference inside glass, the method of forming a recessed part in the back surface of an up-and-down type | mold is described.

Japanese Patent Laid-Open No. 2-111635

  However, when the optical element material is molded using a mold set having a barrel mold as described in Patent Document 1, the stage surface rubs against the bottom surface of the lower mold and the trunk mold when transported on the stage. . At this time, the smoothness of the stage surface is impaired in the lower mold and the body mold due to generation of wear powder due to wear and adhesion to the stage surface.

  On a stage with a rough surface, problems such as tilting of the upper and lower molds and changes in heat transfer from the stage to the mold set over time occur. For this reason, maintenance for maintaining smoothness is required, and the operating rate is lowered.

  An object of the present invention is to provide an optical element manufacturing method, an optical element molding die set, and an optical element that can prevent a reduction in operating rate at the time of manufacturing an optical element and can manufacture a stable quality optical element. It is to provide a manufacturing apparatus.

  An optical element manufacturing method of the present invention is accommodated in an optical element molding die set having an upper die and a lower die arranged to face each other, and a barrel die arranged around the upper die and the lower die. A heating process for heating the optical element material, a pressurizing process for pressurizing the heated optical element material, and a cooling process for cooling the pressurized optical element material. The step, the pressurizing step, and the cooling step are performed by sequentially transporting the optical element molding die set to a plurality of stages, and a groove is formed on the bottom surface of the barrel mold. Both ends of the groove in the forming direction are opened at the outer peripheral surface of the body mold, and the groove includes the entire bottom surface of the lower mold in the bottom view of the body mold. Is formed in parallel with the conveying direction of the optical element molding die set. The optical element molding die set is conveyed to slide so that.

  An optical element molding die set according to the present invention includes an upper die and a lower die that are arranged opposite to each other, and a barrel die that is arranged around the upper die and the lower die. Is formed with a groove, and both ends of the groove in the groove forming direction are opened at the outer peripheral surface of the body mold, and the groove is formed on the bottom surface of the lower mold in the bottom view of the body mold. Including the whole.

In the optical element molding die set, the groove may be formed in a straight line.
In the optical element molding die set, the body mold includes a first body mold and a second body mold disposed around the first body mold, and the groove includes at least You may make it form in the said 2nd trunk | drum type | mold.

In the optical element molding die set, the groove may be formed only in the second body mold, and the material of the second body mold may be softer than the material of the lower mold.
In the optical element molding die set, the material of the upper die, the lower die, and the first barrel die includes at least one of cemented carbide, cermet, and ceramics, and the second The body material includes austenitic or martensitic stainless steel, the cemented carbide is mainly composed of tungsten carbide (WC), and the cermet is composed of titanium nitride (TiN) and titanium carbide (TiC). , Chromium carbide (Cr ₃ C ₂ ), and alumina (Al ₂ O ₃ ) as the main component, and the ceramics are alumina (Al ₂ O ₃ ), sapphire (Al ₂ O ₃ ), silicon carbide (SiC). ), chromium carbide _{(Cr 3 C} 2), silicon nitride _{(Si 3 N} 4), and is either boron nitride (BS) Unishi may be.

  The optical element manufacturing apparatus of the present invention includes any one of the above-described optical element molding mold sets, and a plurality of stages to which the optical element molding mold set is sequentially conveyed. In each of the plurality of stages, At least one of heating, pressurization, and cooling of the optical element material is performed.

  In the optical element manufacturing apparatus, the optical element molding die set is slid and conveyed so that the groove forming direction is parallel to the conveying direction of the optical element molding die set in the plurality of stages. You may be made to do.

  In the optical element manufacturing apparatus, at least one of the plurality of stages is in contact with a pair of convex portions located across the groove of the optical element molding die set, and the optical element molding die A pair of conveyance guide grooves extending in the conveyance direction of the set and shallower than the groove may be formed.

  In the optical element manufacturing apparatus, an inclined surface is formed in the pair of conveyance guide grooves, and the pair of convex portions of the optical element molding die set is in contact with the inclined surface of the groove. You may make it have a surface.

  In the optical element manufacturing apparatus, the pair of convex portions of the optical element molding die set includes a contact surface that contacts the pair of conveyance guide grooves of the stage and a recess that is a non-contact surface. May be alternately formed, and the recesses of the optical element molding die set may extend in a direction intersecting the transport direction.

  In the optical element manufacturing apparatus, the concave portion of the optical element molding die set may open to the outer peripheral surface of the optical element molding die set on the rear side in the transport direction.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to prevent the fall of the operation rate at the time of optical element manufacture, the optical element of the stable quality can be manufactured.

It is sectional drawing which shows the internal structure of the manufacturing apparatus of the optical element which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the optical element shaping | molding die set which concerns on 1st Embodiment of this invention. It is a bottom view which shows the 2nd trunk | drum type | mold in 1st Embodiment of this invention. It is a side view which shows the 2nd trunk | drum type | mold in 1st Embodiment of this invention. It is a perspective view which shows the 2nd trunk | drum type | mold in 1st Embodiment of this invention. It is the A section enlarged view of Drawing 3C. It is a bottom view which shows the type | mold set 10-2 which concerns on the 1st modification of 1st Embodiment of this invention. It is sectional drawing which shows the upper heating plate in which the protrusion part was provided in the 2nd modification of 1st Embodiment of this invention. It is sectional drawing which shows the type | mold set which concerns on 2nd Embodiment of this invention. It is a bottom view which shows the type | mold set which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the lower heating board in 3rd Embodiment of this invention. It is the B section enlarged view of Drawing 7A. It is a perspective view which shows the lower heating board and type | mold set in 3rd Embodiment of this invention. It is the C section enlarged view of FIG. 8A. It is a perspective view which shows the lower heating board and type | mold set in 4th Embodiment of this invention. It is a bottom view which shows the type | mold set which concerns on 5th Embodiment of this invention.

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

<First Embodiment>
FIG. 1 is a cross-sectional view showing the internal structure of the optical element manufacturing apparatus 1 according to the first embodiment of the present invention.

FIG. 2 is a cross-sectional view and a bottom view showing the optical element molding die set 10 according to the present embodiment.
3A to 3C are a bottom view, a side view, and a perspective view showing the second body mold 14 of the mold set 10 for molding.

FIG. 3D is an enlarged view of a part A in FIG. 3C.
An optical element manufacturing apparatus 1 shown in FIG. 1 includes a molding chamber 2, a heating / pressurizing stage 3, a cooling stage 4, air cylinders 5, 6, a gas inflow portion 7, a gas outflow portion 8, and an optical device. An element molding die set 10. The heating / pressurizing stage 3 and the cooling stage 4 are examples of a plurality of stages in which at least one of heating, pressurizing, and cooling of the optical element material 100 is performed by sequentially transporting the mold set 10.

  Inside the molding chamber 2, a heating / pressurizing stage 3 and a cooling stage 4 are arranged. The molding chamber 2 is provided with a carry-in shutter 2a and a carry-out shutter 2b. The carry-in shutter 2a and the carry-out shutter 2b reciprocate between a closed position and an open position above the closed position.

  The heating / pressurizing stage 3 includes an upper heating plate 3a and a lower heating plate 3b, which are examples of abutting members that abut on an optical element molding die set (hereinafter, simply referred to as “die set”) 10, and a base. 3c and cartridge heaters 3d and 3e, which are examples of a heating unit that heats the optical element material 100.

  The upper heating plate 3a and the lower heating plate 3b are disposed to face each other. Two cylindrical cartridge heaters 3d and 3e are inserted into the upper heating plate 3a and the lower heating plate 3b, respectively.

  The upper heating plate 3 a is connected to the air cylinder 5, and moves up and down by the air cylinder 5. The air cylinder 5 is an example of a pressurizing unit that pressurizes the optical element material 100. The lower heating plate 3 b is fixed to a base 3 c fixed to the bottom surface of the molding chamber 2.

  The cooling stage 4 includes an upper cooling plate 4a and a lower cooling plate 4b that are examples of abutting members that abut against the mold set 10, a base 4c, and a cartridge heater 4d that is an example of a cooling unit that cools the optical element material 100. , 4e.

  The upper cooling plate 4a and the lower cooling plate 4b are disposed to face each other. Two cylindrical cartridge heaters 4d and 4e are inserted into the upper cooling plate 4a and the lower cooling plate 4b, respectively.

  The upper cooling plate 4 a is connected to the air cylinder 6 and moves up and down by the air cylinder 6. The air cylinder 6 is an example of a pressurizing unit that pressurizes the optical element material 100. The lower cooling plate 4 b is fixed to a base 4 c fixed to the bottom surface of the molding chamber 2.

The gas inflow portion 7 allows an inert gas such as nitrogen (N ₂ ) to flow into the molding chamber 2. Further, the gas outflow portion 8 allows the gas in the molding chamber 2 to flow out. Thus, the inside of the molding chamber 2 can be replaced with the inert gas.

  As shown in FIG. 2 and FIGS. 3A to 3D, the mold set 10 is a first mold that is an example of an upper mold 11, a lower mold 12, and a body mold disposed around the upper mold 11 and the lower mold 12. A body mold 13 and a second body mold 14.

The upper mold 11 and the lower mold 12 are disposed to face each other. The upper mold 11 and the lower mold 12 have a substantially cylindrical shape.
On the bottom surface of the upper mold 11, a concave molding surface 11 a that is mirror-polished and transfers the convex shape to the optical element material 100 is formed. A flange portion 11 b is formed at the upper end of the upper mold 11.

  On the upper surface of the lower mold 12, a concave molding surface 12 a that is mirror-polished and transfers the convex shape to the optical element material 100 is also formed. A flange portion 12 b is also formed at the lower end of the lower mold 12.

  The first body mold 13 has a cylindrical shape, and is disposed around the upper mold 11 and the lower mold 12, for example, between the flange portions 11b and 12b. The upper mold 11 and the lower mold 12 are fitted to the inner peripheral surface of the first body mold 13 on the outer peripheral surface. The first body mold 13 can slide the upper mold 11 and the lower mold 12.

  The second body mold 14 has a cylindrical shape with an outer periphery being an octagon and an inner periphery being circular, and is disposed around the first body mold 13. On the inner peripheral surface of the second body mold 14, only the first body mold 13, or the first body mold 13 and the flange portions 11 b and 12 b of the upper mold 11 and the lower mold 12 are arranged on the outer peripheral surface. Slide. The second body mold 14 is in contact with the above-described upper heating plate 3a, so that the amount of pressing of the optical element material 100 by pressing is adjusted, and the optical element has a desired thickness.

  As shown in FIG. 3A, a groove 14c is formed, for example, in a straight line on the bottom surface of the second body mold 14. The groove 14c opens to the outer peripheral surface of the second body mold 14 (die set 10) at both ends in the groove forming direction (for example, the longitudinal direction of the groove and the same direction as the conveying direction D). The lower mold 12 is formed so as to include the entire bottom surface 12c (leading lines are indicated by dotted lines). That is, a groove 14c that is continuously opened from a part of the outer peripheral surface of the second cylinder mold 14 to a part of the outer peripheral surface facing the second cylinder mold 14 is formed at the bottom of the second cylinder mold 14. . And the bottom part of the lower mold | type 12 is located inside the groove | channel 14c. Therefore, in the mold set 10 on the stage, when viewed in the transport direction D from the bottom of the lower mold 12, it can be said that the bottom of the second body mold 14 is floating from the stage (not in contact with the stage). A pair of convex portions 14a and 14b are formed at both ends of the second body mold 14 so as to sandwich the groove 14c.

  The groove 14c opens to the outer peripheral surface of the mold set 10 at both ends. The width of the groove 14 c is not less than the outer diameter of the lower mold 12 and is a size between the outer diameter and the inner diameter of the second body mold 14. As described above, the groove 14 c is formed so as to include the entire bottom surface 12 c of the lower mold 12.

  The upper mold 11, the lower mold 12, and the first body mold 13 are made of, for example, a cemented carbide containing tungsten carbide (WC) as a main component. Note that “main component” means, for example, that it has a component of 90 wt% or more (the same applies hereinafter). The second body mold 14 is made of, for example, austenitic stainless steel (SUS304).

  The material of the upper mold 11, the lower mold 12, and the first body mold 13 desirably includes at least one of cemented carbide, cermet, and ceramics. The material of the second body mold 14 preferably includes austenitic or martensitic stainless steel.

More preferably, the cermet is mainly composed of any one of titanium nitride (TiN), titanium carbide (TiC), chromium carbide (Cr ₃ C ₂ ), and alumina (Al ₂ O ₃ ). The ceramics include alumina (Al ₂ O ₃ ), sapphire (Al ₂ O ₃ ), silicon carbide (SiC), chromium carbide (Cr ₃ C ₂ ), silicon nitride (Si ₃ N ₄ ), and boron nitride ( BS) is more desirable.

  By using the above material, the material of the second body mold 14 is softer than the material of the lower mold 12. Therefore, the second body mold 14 is more easily worn than the lower mold 12, and wear powder is more likely to be generated.

Hereinafter, an optical element manufacturing method using the optical element manufacturing apparatus 1 will be described.
First, as shown in FIG. 2, the first body mold 13 is fitted on the outer peripheral surface of the lower mold 12 of the mold set 10 on the inner peripheral surface. Next, the optical element material 100 is placed on the molding surface 12a of the lower mold 12 so as to coincide with the center of the molding surface 12a. In the present embodiment, the optical element material 100 has a spherical shape.

  Next, the upper mold 11 is fitted into the inner peripheral surface of the first body mold 13 on the outer peripheral surface from above the optical element material 100. Furthermore, the second body mold 14 is fitted on the outer peripheral surface of the flanges 11 b and 12 b of the combined upper mold 11 and lower mold 12 and the first body mold 13 on the inner peripheral surface. Thus, the introduction (accommodation) of the optical element material 100 into the mold set 10 is completed.

Next, a process of forming the optical element 100 by molding the optical element material 100 in the mold set 10 will be described.
First, the mold set 10 assembled as described above is carried in between the upper heating plate 3a and the lower heating plate 3b in which the cartridge heaters 3d and 3e are heated to a predetermined temperature in advance when the carry-in shutter 2a is opened. .

  Next, the air cylinder 5 lowers the upper heating plate 3a, and the upper heating plate 3a comes into contact with the upper surface of the upper mold 11, so that the optical element material 100 sandwiched and accommodated in the mold set 10 is, for example, glass-bending It is heated to a temperature equal to or higher than the point (when the optical element material 100 is made of glass) and can be pressurized (heating process).

  Next, in the heating / pressurizing stage 3, the optical cylinder 100 is pressurized (pressurized) by the air cylinder 5 pressing (clamping) the mold set 10 from above to below via the upper heating plate 3 a. Pressure process). At this time, when the upper die 11 is pressed from the upper side to the lower side, the optical element material 100 heated to a temperature equal to or higher than the glass yield point is softened by heating, so that the upper die 11 and the lower die 12 are molded. It is crushed by the surfaces 11a and 12a and becomes an optical element shape.

Further, when the optical element material 100 is crushed, the upper heating plate 3a comes into contact with the upper end surface of the second body mold 14 and stops at a position where the optical element material 100 has a predetermined center thickness in advance.
Thereafter, the mold set 10 is slid and conveyed while the bottom surface 12 c of the lower mold 12 is in contact with the heating / pressurizing stage 3 and the cooling stage 4. At this time, the mold set 10 is transported such that the groove 14c is parallel to the transport direction D.

  Then, in the cooling stage 4, the optical element material 100 is cooled until it falls to a predetermined temperature (cooling process). In this cooling step, for example, the air cylinder 6 lowers the upper cooling plate 4 a and brings the upper cooling plate 4 a into contact with the upper surface of the upper mold 11. Then, the optical element material 100 sandwiched and accommodated in the mold set 10 is cooled by cartridge heaters 4d and 4e set to a cooling temperature or natural cooling.

  At this time, the materials of the upper die 11 and the lower die 12 (tungsten carbide) and the second barrel die 14 (austenitic stainless steel) are different, and the volume shrinkage due to cooling is higher in the second barrel die 14. 11 and the lower mold 12 are larger. Therefore, only the upper mold 11 comes into contact with the upper cooling plate 4a of the cooling stage 4 when the second body mold 14 contracts greatly. Thereby, pressure can be applied to the optical element (optical element material 100) by the upper mold 11 even during cooling.

  After the mold set 10 is cooled to a temperature range where it can be taken out, the mold set 10 is slid and conveyed so that the groove 14c is parallel to the conveyance direction D. The mold set 10 is outside the molding chamber 2 when the carry-out shutter 2b is opened. It is carried out to. Then, the manufactured optical element is taken out from the mold set 10.

The results of manufacturing the optical element as described above and evaluating the quality of the lower heating plate 3b and the lower cooling plate 4b will be described below.
As described above, the optical element is manufactured by providing the groove 14c in the mold set 10 and transporting the mold set 10 so that the groove 14c is parallel to the transport direction D, and the optical element without providing the groove 14c. Comparison with the case of manufacturing (conventional) was performed.

  When the optical element is manufactured by sliding the mold set 10 without providing the groove 14c as in the prior art, the mold set 10 is loaded 5000 times into the optical element manufacturing apparatus 1 to mold the optical element. At the stage, the lower heating plate 3b and the lower cooling plate 4b rubbed against the bottom surface of the second body die 14. In addition, as a result, the abrasion powder generated from the second body mold 14 is fixed to the surfaces of the lower heating plate 3b and the lower cooling plate 4b, and the mold set 10 is placed on the lower heating plate 3b and the lower cooling plate 4b. It was confirmed that the upper mold 11 and the lower mold 12 were tilted. Therefore, it becomes difficult to maintain the desired accuracy of the optical element, and maintenance is performed.

  On the other hand, when molding is performed as in the present embodiment, the mold set 10 is loaded 50000 times (10 times the conventional size) into the optical element manufacturing apparatus 1 until the optical element is molded, and the accuracy of the optical element is increased. Was able to be maintained. As a result, the number of maintenance operations has been reduced and the operating rate has been improved compared to conventional methods.

  In the present embodiment described above, the bottom surface of the second body mold 14 is formed with a groove 14c that opens to the outer peripheral surface at both ends and includes the entire bottom surface 12c of the lower mold 12 in the bottom view. Thus, when the mold set 10 is transported on the stage (the lower heating plate 3b and the lower cooling plate 4b) by making the groove 14c parallel to the transport direction D of the mold set 10, the second cylinder The mold 14 is in contact with the stage surface at a portion other than the contact surface between the lower mold 12 and the stage surface. Therefore, it is possible to prevent generation of wear powder due to wear, and in turn, prevent the wear powder from sticking to the stage surface, and maintain the smoothness of the stage surface.

  Therefore, it is possible to suppress the lower heating plate 3b and the lower cooling plate 4b (stage surface) from being rough and the postures of the upper mold 11 and the lower mold 12 from being tilted and the heat transfer from the stage to the mold set 10 from being changed over time. Stable quality optical elements can be manufactured. Furthermore, maintenance for maintaining the smoothness of the stage can be omitted to prevent a reduction in operating rate.

  Therefore, according to the present embodiment, it is possible to prevent a reduction in the operation rate at the time of manufacturing the optical element, and it is possible to manufacture an optical element having a stable quality.

  In the present embodiment, the groove 14c is formed in a straight line. Therefore, the smoothness of the stage surface can be further maintained.

  In the present embodiment, the material of the upper mold 11, the lower mold 12, and the first body mold 13 includes at least one of cemented carbide, cermet, and ceramics, and the groove 14c is formed. The material of the second barrel mold 14 includes austenitic or martensitic stainless steel.

The cemented carbide has tungsten carbide (WC) as a main component. The cermet contains titanium nitride (TiN), titanium carbide (TiC), chromium carbide (Cr ₃ C ₂ ), or alumina (Al ₂ O ₃ ) as a main component. The ceramics include alumina (Al ₂ O ₃ ), sapphire (Al ₂ O ₃ ), silicon carbide (SiC), chromium carbide (Cr ₃ C ₂ ), silicon nitride (Si ₃ N ₄ ), and boron nitride ( BS).

  Therefore, rubbing with the surface of the stage can be suppressed by the material of the second body mold 14 while the optical element is manufactured with high accuracy by the materials of the upper mold 11, the lower mold 12, and the first body mold 13.

  In addition, as shown in FIG. 4 (bottom view showing the mold set 10-2 according to the first modification), the second body mold 14-2 has a circular cylindrical shape not only on the inner periphery but also on the outer periphery. There is no particular limitation as long as it is arranged around the first body mold 13. Further, as shown in FIG. 4, the width of the groove 14 c-1 may be larger than the width of the bottom surface 12 c of the lower mold 12.

  Further, as shown in FIG. 5 (a cross-sectional view showing the upper heating plate 3a-3 provided with the protruding portion 3f in the third modification), the upper heating plate 3a-3 (and FIG. 1 is provided on at least one of the upper cooling plates 4a shown in FIG. 1, and a projection 3f smaller than this is provided, and the projection 3f is inserted into the second body die 14 to press the upper die 12. May be.

  In the present embodiment, the optical element manufacturing apparatus 1 includes two stages of a heating / pressurizing stage 3 and a cooling stage 4 as an example of a plurality of stages on which the mold set 10 is sequentially conveyed. You may make it provide the above stage. In that case, the heating / pressurizing stage 3 may be divided into a heating stage and a pressurizing stage, or a plurality of heating, pressurizing, and cooling stages may be arranged.

Second Embodiment
6A and 6B are a sectional view and a bottom view showing a mold set 20 according to the second embodiment of the present invention.

  The present embodiment is mainly different from the first embodiment in that the mold set 20 has only the first body mold 23 as a body mold and that the groove 23c is formed in the first body mold 23. Description of points common to the first embodiment is omitted.

As shown in FIGS. 6A and 6B, the mold set 20 includes an upper mold 21, a lower mold 22, and a first body mold 23.
The upper mold 21 and the lower mold 22 are arranged to face each other. The upper mold 21 and the lower mold 22 have a substantially cylindrical shape.

  On the bottom surface of the upper mold 21 and the upper surface of the lower mold 22, concave molding surfaces 21a and 22a for transferring a convex shape to the optical element material 100 are formed as in the first embodiment. In the present embodiment, the upper mold 21 and the lower mold 22 are not formed with a flange portion.

  The first body mold 23 has a cylindrical shape with an outer periphery being an octagon and an inner periphery being circular, and is disposed around the upper mold 21 and the lower mold 22. The upper mold 21 and the lower mold 22 are fitted on the inner peripheral surface of the first body mold 23 on the outer peripheral surface. The first body mold 23 can slide the upper mold 21 and the lower mold 22.

  As shown in FIG. 6B, a groove 23c is formed on the bottom surface of the first body mold 23, for example, in a straight line. The groove 23c opens to the outer peripheral surface of the first body mold 23 (die set 20) at both ends in the groove forming direction (for example, the longitudinal direction of the groove and the same direction as the conveying direction D). The lower mold 22 is formed so as to include the entire bottom surface 22b. A pair of convex portions 23a and 23b are formed at both ends of the first body mold 23 with the groove 23c interposed therebetween.

  The groove 23c of the mold set 20 in this embodiment also opens at the outer peripheral surface of the mold set 20 at both ends. The width of the groove 23 c is not less than the outer diameter of the lower mold 22 and is a size between the outer diameter and the inner diameter of the first body mold 23. As described above, the groove 23 c is formed so as to include the entire bottom surface of the lower mold 22.

  The optical element manufacturing method is the same as that in the first embodiment. However, in order to press the upper mold 21, as shown in FIG. 5, an upper heating plate 3 a provided with a protruding portion 3 f is used. A configuration in which the portion 3 f is inserted into the first body mold 23 to press the upper mold 22 may be employed.

  Also in the second embodiment described above, as in the first embodiment, when the mold set 20 is transported on the stage (the lower heating plate 3b and the lower cooling plate 4b), the first body mold 23 is It contacts the stage surface at a portion other than the contact surface between the mold 22 and the stage surface. Therefore, it is possible to prevent generation of wear powder due to wear, and in turn, prevent the wear powder from sticking to the stage surface, and maintain the smoothness of the stage surface.

  Therefore, according to this embodiment as well, it is possible to prevent a reduction in operating rate at the time of manufacturing the optical element, and it is possible to manufacture an optical element having a stable quality.

<Third Embodiment>
FIG. 7A is a perspective view showing the lower heating plate 3b in the third embodiment of the present invention.
FIG. 7B is an enlarged view of a portion B in FIG. 7A.

FIG. 8A is a perspective view showing the lower heating plate 3b and the mold set 10 in the present embodiment.
FIG. 8B is an enlarged view of a portion C in FIG. 8A.
In the present embodiment, the lower heating plate 3b (lower cooling plate 4b) of the heating stage 3 (cooling stage 4) abuts the pair of convex portions 14a and 14b of the mold set 10 of the first embodiment described above, and the conveying direction This is mainly different from the first embodiment in that a pair of conveyance guide grooves 3g and 3h extending in D and shallower than the groove 14c are formed. Description of points common to the first embodiment is omitted.

  As shown in FIG. 7A, a pair of conveyance guide grooves 3g and 3h extending in the conveyance direction D are formed in the lower heating plate 3b. As shown in FIG. 7B, the pair of conveyance guide grooves 3g and 3h has a rectangular cross section, and opens on the surface of the lower heating plate 3b at the long side of the rectangle.

  As shown in FIGS. 8A and 8B, in the cross section orthogonal to the transport direction D, the pair of transport guide grooves 3 g and 3 h of the lower heating plate 3 b are the convex portions 14 a and 14 b of the second body mold 14 of the mold set 10. Wider than.

  Further, since the depth of the grooves 3g and 3h is smaller than the protruding amount of the convex portions 14a and 14b, the groove 14c of the mold set 10 is not in contact with the lower heating plate 3b.

  Note that a pair of conveyance guide grooves similar to the pair of conveyance guide grooves 3g and 3h of the lower heating plate 3b may be formed on the lower cooling plate 4b, and at least one of the plurality of stages is described above. A pair of conveyance guide grooves 3g and 3h may be formed. In the present embodiment, the mold set 20 of the second embodiment described above may be used.

  In the present embodiment described above, the lower heating plate 3b (at least one of the plurality of stages) of the heating / pressurizing stage 3 is in contact with the convex portions 14a and 14b of the mold set 10 and extends in the conveying direction D. A pair of conveyance guide grooves 3g and 3h shallower than 14c are formed. Therefore, in addition to obtaining the same effects as those of the first embodiment, the generated wear powder can be stored in the pair of conveyance guide grooves 3g and 3h, and the mold is set by the pair of conveyance guide grooves 3g and 3h. 10 can be obtained.

<Fourth embodiment>
FIG. 9 is a perspective view showing the lower heating plate 3b and the mold set 30 in the fourth embodiment of the present invention.

  In the present embodiment, a pair of conveyance guides that extend in the conveyance direction D are brought into contact with the pair of convex portions 34 a and 34 b of the mold set 30 on the lower heating plate 3 b (lower cooling plate 4 b) of the heating stage 3 (cooling stage 4). This is mainly different from the first embodiment in that the grooves 3i and 3j are formed. Description of points common to the first embodiment is omitted.

  As shown in FIG. 9, a pair of conveyance guide grooves 3i and 3j extending in the conveyance direction D are formed in the lower heating plate 3b. The pair of conveyance guide grooves 3i, 3j are formed with inclined surfaces 3k, 3L, and the cross-sectional shape of the pair of conveyance guide grooves 3i, 3j is a trapezoidal shape that opens on the stage surface at the upper base longer than the lower base. .

Of the mold set 30, the upper mold 31, the lower mold 32, and the first body mold 33 are the same as those of the mold set 10 of the first embodiment.
Similarly to the second body mold 14 of the mold set 10 of the first embodiment, the second body mold 34 of the mold set 30 also has a cylindrical shape with an octagonal outer periphery and a circular inner periphery. It is arranged around the mold 33.

  However, in the second body mold 34 of the present embodiment, the protruding amount of the pair of convex portions 34a and 34b increases from the center side toward the outer peripheral end, and the bottom surface of the convex portions 34a and 34b is a pair of transports. The inclined surfaces are in contact with the inclined surfaces 3k and 3L of the guide grooves 3i and 3j.

  As shown in FIG. 9, since the depth of the pair of conveyance guide grooves 3i and 3j is smaller than the protruding amount of the convex portions 34a and 34b, the groove 34c of the mold set 30 is not in contact with the lower heating plate 3b. . In the present embodiment, both ends open to the outer peripheral surface in the region between the tips (lower ends) of the protrusions 34a and 34b (almost coincident with the width orthogonal to the conveyance direction D of the mold set 30), but are not in contact with the stage. The portion of the groove 34c that becomes the width is larger than the bottom surface 32a of the lower mold 32 and extends over the pair of inclined surfaces 3k and 3L.

  The lower cooling plate 4b may be formed with a pair of conveyance guide grooves similar to the pair of conveyance guide grooves 3i and 3j of the lower heating plate 3b, and at least one of the plurality of stages is described above. A pair of conveyance guide grooves 3i, 3j may be formed.

  In the present embodiment described above, the lower heating plate 3b (at least one of the plurality of stages) of the heating / pressurizing stage 3 is in contact with the convex portions 34a and 34b of the mold set 30 and extends in the transport direction D. The conveyance guide grooves 3i and 3j are formed. Therefore, in addition to obtaining the same effect as in the first embodiment described above, the generated wear powder can be stored in the pair of conveyance guide grooves 3i, 3j, as in the third embodiment described above, and a pair of It is possible to obtain an effect that the mold set 30 can be guided by the conveyance guide grooves 3i and 3j.

  In the present embodiment, the pair of conveyance guide grooves 3i, 3j are formed with inclined surfaces 3k, 3L, and the convex portions 34a, 34b are in contact with the inclined surfaces 3k, 3L of the pair of conveyance guide grooves 3i, 3j. It has an inclined surface that touches. Therefore, by reliably guiding the mold set 30, it is possible to prevent the convex portions 34a and 34b of the mold set 30 from rubbing against the pair of conveyance guide grooves 3i and 3j due to rattling.

<Fifth Embodiment>
FIG. 10 is a bottom view showing a mold set 40 according to the fifth embodiment.
The mold set 40 of the present embodiment is mainly different from the mold set 10 of the first embodiment in that the concave portions 44c and 44d are formed in the convex portions 44a and 44b. Therefore, this difference will be mainly described.

  A plurality of contact surfaces that contact the stage and recesses 44c and 44d that are non-contact surfaces are formed alternately on the projections 44a and 44b. These recesses 44 c and 44 d extend in a direction intersecting the transport direction D, and open on the outer peripheral surface of the mold set 40 on the rear side in the transport direction D.

  Therefore, it is easy for the wear powder to be discharged to the outside of the mold set 40 through the recesses 44c and 44d while preventing the projections 44a and 44b from rubbing against the stage, and the wear powder accumulates on the projections 44a and 44b. Can be prevented.

DESCRIPTION OF SYMBOLS 1 Optical element manufacturing apparatus 2 Molding chamber 2a Carrying-in shutter 2b Carrying-out shutter 3 Heating / pressurizing stage 3a Upper heating plate 3b Lower heating plate 3c Base 3d, 3e Cartridge heater 3f Protruding part 3g, 3h Conveying guide groove 3i, 3j Conveying guide groove 3k, 3L Inclined surface 4 Cooling stage 4a Upper cooling plate 4b Lower cooling plate 4c Base 4d, 4e Cartridge heater 5, 6 Air cylinder 7 Gas inflow portion 8 Gas outflow portion 10 Type set 11 Upper die 11a Molding surface 11b Flange part 12 Lower mold 12a Molding surface 12b Flange part 12c Bottom surface 13 First body mold 14 Second body mold 14a, 14b Projection part 14c Groove 20 Mold set 21 Upper mold 21a Molding surface 22 Lower mold 22a Molding surface 22b Bottom surface 23 First body mold 23a, 23b Protruding part 23c Groove 30 Mold set 31 Upper mold 32 Lower 32a bottom surface 33 first body mold 34 second body mold 34a, 34b convex portion 34c groove 40 type set 42 the lower mold 42a bottom surface 44 second body mold 44a, 44b convex portion 44c, 44d recess 44e groove 100 optical element material

Claims (12)

Heating for heating an optical element material housed in an optical element molding mold set having an upper mold and a lower mold disposed opposite to each other, and a body mold disposed around the upper mold and the lower mold Process,
A pressurizing step for pressurizing the heated optical element material;
A cooling step of cooling the pressurized optical element material, and
The heating step, the pressurizing step, and the cooling step are performed by sequentially transporting the optical element molding die set to a plurality of stages,
A groove is formed on the bottom surface of the body mold,
Both ends of the groove in the groove forming direction are opened at the outer peripheral surface of the body mold,
The groove includes the entire bottom surface of the lower mold in the bottom view of the trunk mold,
In the plurality of stages, the optical element molding die set is slid and conveyed so that the groove forming direction is parallel to the conveying direction of the optical element molding die set. An upper mold and a lower mold arranged opposite to each other;
A body mold disposed around the upper mold and the lower mold,
A groove is formed on the bottom surface of the body mold,
Both ends of the groove in the groove forming direction are opened at the outer peripheral surface of the body mold,
The groove is an optical element molding die set including the entire bottom surface of the lower die in the bottom view of the body die.   The optical element molding die set according to claim 2, wherein the groove is formed in a straight line. The trunk mold includes a first trunk mold and a second trunk mold disposed around the first trunk mold,
4. The optical element molding die set according to claim 2, wherein the groove is formed in at least the second body mold. 5. The groove is formed only in the second body mold,
The optical element molding die set according to claim 4, wherein a material of the second body mold is softer than a material of the lower mold. The material of the upper mold, the lower mold, and the first body mold includes at least one of cemented carbide, cermet, and ceramics,
The material of the second body type includes austenitic or martensitic stainless steel,
The cemented carbide is mainly composed of tungsten carbide (WC),
The cermet is mainly composed of any one of titanium nitride (TiN), titanium carbide (TiC), chromium carbide (Cr ₃ C ₂ ), and alumina (Al ₂ O ₃ ),
The ceramics include alumina (Al ₂ O ₃ ), sapphire (Al ₂ O ₃ ), silicon carbide (SiC), chromium carbide (Cr ₃ C ₂ ), silicon nitride (Si ₃ N ₄ ), and boron nitride (BS). The optical element molding die set according to claim 5, which is any one of the above. An optical element molding die set according to any one of claims 2 to 6,
A plurality of stages on which the optical element molding die set is sequentially conveyed, and
An optical element manufacturing apparatus in which at least one of heating, pressurization, and cooling of an optical element material is performed in each of the plurality of stages.   8. The optical element according to claim 7, wherein the optical element molding die set is slid and conveyed so that a forming direction of the groove is parallel to a conveyance direction of the optical element molding mold set. Manufacturing equipment.   At least one of the plurality of stages is in contact with a pair of convex portions located across the groove of the optical element molding die set, and extends in the transport direction of the optical element molding die set, The optical element manufacturing apparatus according to claim 7, wherein a pair of shallower conveying guide grooves is formed. An inclined surface is formed in the pair of conveyance guide grooves,
The optical element manufacturing apparatus according to claim 9, wherein the pair of convex portions of the optical element molding die set has an inclined surface that comes into contact with the inclined surface of the groove. In the pair of convex portions of the optical element molding die set, a plurality of contact surfaces that are in contact with the pair of conveyance guide grooves of the stage and concave portions that are non-contact surfaces are alternately formed.
11. The optical element manufacturing apparatus according to claim 9, wherein the concave portion of the optical element molding die set extends in a direction intersecting the transport direction.   The optical element manufacturing apparatus according to claim 11, wherein the concave portion of the optical element molding die set opens on an outer peripheral surface of the optical element molding die set on a rear side in the transport direction.

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