JP2000326355A - Optical element mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element mold which is constituted so that occurrence of a flash can be suppressed. SOLUTION: The optical element mold 3 is for molding an optical material 1 received in a cavity 3a enclosed by a top force 4, a bottom force 5 and a trunk mold 6. In this case, a thermal conductivity of the top force 4 and the bottom force 5, and a thermal conductivity of the trunk mold 6 are mutually difference, and when the thermal conductivity of the top force 4 and the bottom force 5 is set to be H1, and the thermal conductivity of the trunk mold 6 is set to be H2, a relation (H1>H2) wherein the thermal conductivity H1 of the top force 4 and the bottom force 5 exceeds the thermal conductivity H2 of the trunk mold 6 is established.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element mold used for manufacturing an optical element, and more particularly, to a constituent material and a shape thereof.

[0002]

2. Description of the Related Art Conventionally, when manufacturing optical elements such as lenses, prisms, and mirrors used in optical equipment, a thermoplastic material such as polycarbonate is used as an optical material. -1777
No. 25, the optical material, which has been made into a substantially final shape by pre-processing, is heated to a temperature not lower than its deflection temperature under load and lower than the glass transition temperature, and the heated optical material is molded into an optical element. A manufacturing method of performing plastic deformation processing using a mold is to be adopted.

[0003] That is, the manufacturing method according to the prior application is a method implemented using an optical element molding die 51 having a configuration as shown in FIG. 7, and the optical element molding dies 51 are combined with each other. Upper mold 52, lower mold 53, and upper body mold 54
The optical material 56 is accommodated in a cavity (not shown) surrounded by the lower body mold 55 and the lower body mold 55. Reference numeral 57 in FIG. 7 denotes a press head, 58 denotes a press stage, and the press head 57 in contact with the upper mold 52 is provided with a heating / pressing mechanism (not shown), while the lower mold 53 is provided.
Heating mechanism (not shown)
Is provided.

Therefore, when manufacturing an optical element, for example, a lens 59 having a sectional shape shown in FIG. 8, the optical material 56 which has been made into a substantially final shape by injection molding is subjected to a load deflection temperature or higher and a glass transition point temperature or lower. When the temperature of the optical material 56 is equal to or higher than the deflection temperature under load and lower than the glass transition point temperature when the temperature of the optical material 56 substantially matches the optical element molding die 51,
About 100kgf / c while lowering the press head 57
The optical element 56 is deformed and held by pressing the optical material 56 with a pressing force of m ² , the pressing force is released, the optical element 56 is cooled to the deflection temperature of the load, and then the optical element molded by removing the upper mold 52 from the optical element forming die 51. Is taken out of the cavity. It is to be noted that the optical element is not limited to the lens 59 but may be a prism, a mirror, or the like.

[0005]

In the conventional optical element molding die 51, the effective surface of the lens 59, that is, the effective surface of the optical element, is formed and transferred between the upper die 52 and the lower die 53, and the cylinder is formed. The lens 59 depends on the inner diameter of the molds 54 and 55.
Since the outer diameter surface is formed, the optical material 56 being pressed penetrates into the clearance (not shown) generated between each of the upper mold 52 and the lower mold 53 and the body molds 54 and 55, In some cases, the lens 59 may be molded as it is. In such a case, as shown in FIG. 8, a burr 59a along the thickness direction remains on the outer diameter surface of the molded lens 59. If a large burr 59a remains, an assembling error of the lens 59 at the time of assembling to the optical device occurs or the performance of the optical device is deteriorated. Therefore, the burr 59a must be removed from the lens 59. In addition, troublesome work is required for the deburring process.

Further, in the deburring process, since it is necessary to position and hold the lens 59, the lens 59 may be damaged, and the yield is reduced. Furthermore, the generated burrs 59
In some cases, a part of “a” may remain in the clearance. In such a case, it is necessary to perform a cleaning operation of the optical element molding die 51 in advance for the next molding. That is, as long as the optical element molding die 51 having the conventional configuration is used, the cost cannot be reduced when manufacturing an optical element such as the lens 59.

The present invention has been made in view of these inconveniences, and has as its object to provide an optical element mold having a configuration capable of suppressing the occurrence of burrs.

[0008]

According to a first aspect of the present invention, there is provided an optical element molding die for molding an optical material housed in a cavity surrounded by an upper die, a lower die and a body die. ,
The thermal conductivity of the upper and lower molds and the thermal conductivity of the body mold are different from each other, the thermal conductivity of the upper and lower molds is H1, and the heat conductivity of the body mold is H2. In this case, the thermal conductivity H1 of the upper mold and the lower mold has a relationship (H1> H2) that exceeds the thermal conductivity H2 of the body mold.

According to a second aspect of the present invention, there is provided an optical element molding die for molding an optical material housed in a cavity surrounded by an upper die, a lower die, and a body die. A body spacer is interposed between at least one of the and the contact part of the body mold, and the thermal conductivity of the upper mold and the lower mold and the heat conductivity of the body mold coincide with each other, and the upper mold and The thermal conductivity of the lower mold and the trunk mold and the thermal conductivity of the trunk spacer are different from each other, and the thermal conductivity of the upper mold, the lower mold and the trunk mold is H1, and the trunk spacer is H1. Is the thermal conductivity H1 of the upper and lower dies and the body mold, the thermal conductivity H1 of the body spacer is H2.
It is characterized in that the relationship is more than two (H1> H2).

[0010]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1 is an external perspective view showing the shape of the optical material according to the first embodiment, FIG. 2 is a sectional view showing the shape of the optical element, and reference numeral 1 in FIG. Reference numeral 2 indicates a lens as an optical element. The optical material 1 is made of a polyolefin (deflection temperature under load Tt = 123).
° C, glass transition temperature Tg = 140 ° C), and the shape shown in Fig. 1 accompanying the cutting of a block cut from a plate or the like, that is, the curvature radius of both convex surfaces is 1.8 mm. It is pre-processed as a substantially spherical shape having a center thickness of 3 mm.

The lens 2 as an optical element has a one-side lens surface 2a having a radius of curvature R1 of 2 mm, the other-side lens surface 2b having a radius of curvature R2 of 7 mm, a center thickness of 1.6 mm, and
The outer diameter was 4.5 mm. Note that the optical material 1 and the lens 2 are not limited to those manufactured using polyolefin, and may be manufactured using other thermoplastic plastic materials such as polycarbonate and acrylic. Of course, the optical element may be a prism, a mirror, or the like. Further, it is needless to say that the optical material 1 is not limited to a cut material, but may be a material pre-processed by injection molding or the like.

FIG. 3 is a sectional view showing the structure of the optical element molding die according to Embodiment 1, FIG. 4 is a sectional view showing the structure of the optical element molding apparatus, and FIG. It is sectional drawing which shows the state of an optical element molding die.
Reference numeral 3 in these figures indicates an optical element molding die, and the optical element molding die 3 includes an upper mold 4 and a lower mold 5.
And a pre-processed optical material 1 in a cavity 3a surrounded by a body mold 6 into which these main parts are fitted, that is,
The optical material 1 shown in FIG. 1 is housed therein.

At this time, each of the upper mold 4 and the lower mold 5 is made of a tungsten carbide, for example, a cemented carbide material such as tungsten carbide containing cobalt, nickel, titanium, and tantalum. On the other hand, the body mold 6 is manufactured using a material having a ceramic base material, and the thermal conductivity of each of the upper mold 4 and the lower mold 5 is 0.2 cal / cm · sec · ° C. The thermal conductivity of the body mold 6 is 0.004 cal / cm.
· Sec · ° C. That is, in the optical element molding die 3, when the thermal conductivity of each of the upper die 4 and the lower die 5 is H1, and the thermal conductivity of the body die 6 is H2, each of the upper die 4 and the lower die 5 Is higher than the thermal conductivity H2 of the shell mold 6 (H1>
H2) is set.

On the other hand, the optical element molding apparatus according to the present invention
As shown in FIGS. 4 and 5, a loading stage 11 on which the optical element molding die 3 containing the optical material 1 is placed, and an unloading stage 12 on which the optical element molding die 3 after the molding is completed is placed.
And a molding chamber 13 provided between the stages 11 and 12. In this optical element molding apparatus, the optical element molding die 3 is placed on the loading stage 11 after using a robot (not shown).
The optical element molding die 3 placed on the take-out stage 12 and disassembled into a mold 2 is a lens 2 which is an optical element already molded.
Is to be taken out. A preheating stage 14, a molding stage 15, and a first stage 15 are provided inside a molding chamber 13 provided with an openable and closable entrance door 13a and an exit door 13b.
Each of the cooling stage 16 and the second cooling stage 17 is arranged in the order from the loading stage 11 to the unloading stage 12.

Further, optical element molding dies, which are mounted while being conveyed by a transfer arm (not shown), are provided at lower positions of the preheating stage 14, the forming stage 15, the first cooling stage 16, and the second cooling stage 17, respectively. The heater 18 for heating the mold 3 to a predetermined temperature is provided, and the optical element molding die 3 is provided above the stages 14 to 17.
Press head 19 for pressing the optical material 1 stored in the optical element 1 with a predetermined pressure, that is, a press head for pressing the upper mold 4 of the optical element molding die 3 downward with a heating / pressing mechanism (not shown) 19 are provided.

The optical element molding die 3 of the present invention
Are heated to the set temperatures shown in Table 1 by heaters 18 provided in each of the preheating stage 14 to the second cooling stage 17. Note that these heaters 18 are configured so that any temperature can be set, and are heated up before the optical element molding die 3 is placed.

[0018]

[Table 1]

Next, a method for manufacturing an optical element, that is, a method for manufacturing the lens 2 performed using the optical element mold 3 according to the present embodiment will be described according to the procedure.
In this manufacturing method, the optical element mold 3 is to be conveyed for 50 seconds at each of the stages 14 to 17, and FIGS. 5A to 5D respectively show the preheating stages 14 to The state of the optical element mold 3 in each of the second cooling stages 17 is shown. First, the optical material 1 which is a pre-processed polyolefin is stored in the cavity 3a of the optical element molding die 3, that is, in the cavity 3a surrounded by the upper die 4, the lower die 5, and the body die 6. Loading stage 11 for optical element molding die 3 containing 1
, The optical element molding die 3 placed on the loading stage 11 is transported by the transport arm to the preheating stage 14 and placed thereon.

In the preheating stage 14, FIG.
As shown in (a), the optical element forming die 3 is heated to a preheating temperature (200 ° C.) by the heater 18 and the optical material 1 is pressed by the press head 19 in contact with the upper die 4 of the optical element forming die 3. Pressing with a small pressing force of 5 kgf or less is performed, and after a predetermined time has elapsed, the optical element molding die 3 is transported to the molding stage 15. Subsequently, in the molding stage 15, as shown in FIG. 5B, the pressing of the optical material 1 by the press head 19 in contact with the upper mold 4 of the optical element molding die 3 is performed. The molding peak temperature of the polyolefin as the optical material 1 exceeding the glass transition temperature Tg = 140 ° C. (200
° C), and the pressure of the press head 19 is set to about 80 kgf because the optical material 1 reaches a molding peak temperature at which the optical material 1 can be deformed in a short time.

At this time, since the upper mold 4 and the lower mold 5 are heated by the heater 18 and the press head 19 and are sandwiched by the upper mold 4 and the lower mold 5, the optical material 1 Is heated from the optical element transfer surface of each of the upper mold 4 and the lower mold 5, that is, the portion in contact with the lens transfer surface.
Is heated by the heat transfer from the upper mold 4 and the lower mold 5. That is, the optical material 1 in the optical element molding die 3 placed on the molding stage 15
5B, as shown in FIG. 5B, is deformed as a result of being pressed while being heated while being pressed at the optical element transfer surfaces of the upper mold 4 and the lower mold 5, that is, the portions in contact with the lens transfer surface. The heated and pressed optical material 1 eventually reaches the inner surface of the barrel mold 6.

However, at this time, the inner surface of the shell mold 6
Due to the difference in thermal conductivity between the upper mold 4 and the lower mold 5, the temperature is lower by about 20 ° C. than the lens transfer surface. The portion in contact with the inner surface of the barrel die 6 is worse than the portion in contact with the lens transfer surface of the lower die 5. Therefore, although not shown, even if there is a clearance (gap) between the main part of the upper mold 4 and the lower mold 5 and the body mold 6 in which these are fitted, the fluidity is poor. The optical material 1 does not enter the clearance,
Burrs along the thickness direction cannot be generated on the outer diameter surface of the molded lens 2.

Further, the optical element molding die 3 having passed a predetermined time in the molding stage 15 is transported to and mounted on the first cooling stage 16 as shown in FIG. The first cooling temperature (130 ° C.) lower than the glass transition temperature Tg = 140 ° C. of the polyolefin that is 1.
After being pressurized below, it is subsequently conveyed to and mounted on the second cooling stage 17, and the second cooling stage 1
7, the second cooling temperature (60 ° C.) lower than the deflection temperature under load Tt = 123 ° C. of the polyolefin as shown in FIG.
C). Then, the optical element molding die 3 on which a series of molding as described above has been completed is conveyed and placed on the take-out stage 12, and the optical element molding die 3 disassembled by the take-out stage 12 is formed.
The lens 2 as an optical element which has been molded is taken out from the apparatus.

By the way, the inventors of the present invention examined the molded lens 2 and found that no burr was generated on the outer diameter surface of the lens 2 and it was not necessary to perform the burr removal processing. Has been confirmed. Note that the deformation temperature, heating time, holding time, cooling time from the deformation temperature to the deflection temperature are not necessarily the same as the conditions shown in the actual embodiment, and may be arbitrarily changed as necessary. Of course. Further, four stages, namely, a preheating stage 14, a molding stage 15, a first cooling stage 16,
It is not necessary to provide the second cooling stage 17, and it is also possible to adopt a configuration in which a plurality of processes, that is, preheating, molding, cooling, and the like are sequentially executed in each stage.

(Embodiment 2) FIG. 6 is a sectional view showing the structure of an optical element molding die according to Embodiment 2, and reference numeral 7 in FIG. 6 denotes an optical element molding die. The shapes of the optical material and the optical element according to the second embodiment, the structure of the optical element molding apparatus, and the like are not basically different from those of the first embodiment, and therefore are not illustrated here and refer to FIGS. 1 to 5. It will be explained.

First, the optical material 1 according to the second embodiment
Is made of acryl (load deflection temperature Tt = 115 ° C., glass transition temperature Tg = 130 ° C.), and has a shape as shown in FIG. 1, that is, a convex surface on both sides having a radius of curvature of 2.9 mm and a center thickness of 3.1 mm. As shown in FIG. 2, the lens 2 which is pre-processed into a substantially spherical shape and is an optical element has a radius of curvature R1 of one lens surface 2a of 2 mm and a radius of curvature R2 of another lens surface 2b of 3 mm. , The center thickness is 3mm,
The outer diameter is 4.7 mm. Note that the optical material 1 and the lens 2 are not limited to those manufactured using polyolefin, and may be manufactured using other thermoplastic plastic materials such as polycarbonate and acrylic. Of course, the optical element may be a prism, a mirror, or the like.

As shown in FIG. 6, the optical element molding die 7 includes an upper die 4 and a lower die 5 and a body die 6 into which main parts thereof are fitted. Mold 5 and body mold 6
A body spacer 8 is interposed between the contact portions of the body 6 with a body 6 by using a heat-resistant adhesive (not shown). In addition, the torso die 6 and the torso spacer 8
Is not necessarily joined to the
Needless to say, the body-shaped spacer 8 and the body-shaped spacer 8 need not be joined. Further, inside the optical element mold 7,
A cavity 7a surrounded by the main part of the upper mold 4 and the lower mold 5 and the body mold 6 is provided.
The pre-processed optical material 1, that is, the optical material 1 shown in FIG. 1 is stored. Incidentally, in FIG.
A body spacer 8 is interposed between the contact portions between the upper mold 4 and the body die 6 (not shown). On the other hand, it is also possible to interpose the trunk type spacer 8 in advance.

At this time, the upper mold 4 and the lower mold 5 and the body mold 6 are made of a super hard material such as cobalt-containing tungsten carbide, while the body mold spacer 8 is made of quartz. It was made using
The thermal conductivity of the upper mold 4 and the lower mold 5 and the body mold 6 is 0.2
cal / cm · sec · ° C.
Has a thermal conductivity of 0.034 cal / cm · sec ·
° C. That is, although the thermal conductivity of the upper mold 4 and the lower mold 5 and the thermal conductivity of the body mold 6 match each other, the heat of the upper mold 4, the lower mold 5, and the body 6 The conductivity and the thermal conductivity of the body spacer 8 are different from each other, and the thermal conductivity of the upper mold 4 and the lower mold 5 and the body mold 6 is H1, and the heat of the body spacer 8 is H1. Assuming that the conductivity is H2, the thermal conductivity H1 of the upper mold 4 and the lower mold 5 and the body mold 6 is higher than the thermal conductivity H2 of the body spacer 8 (H1> H2).

Further, as shown in FIG. 4 and FIG.
1 and the take-out stage 12, and these stages 11, 1
And a molding chamber 13 provided between the two. A preheating stage 14, a molding stage 15, and a first stage are provided inside the molding chamber 13 provided with an openable and closable entrance door 13a and an exit door 13b. Cooling stage 16, second cooling stage 1
7 are from the loading stage 11 to the unloading stage 12
They are arranged in the order toward. At the lower position of each of the stages 14 to 17, a heater 18 for heating the optical element molding die 7, which is transported by the transport arm (not shown) and placed, to a predetermined temperature is provided. A press head 19 for pressing the optical material 1 in the optical element molding die 7 with a predetermined pressure is provided at an upper position of the optical element molding die 7, and the optical head mounted on each of the preheating stage 14 to the second cooling stage 17 is provided. The element mold 3 is to be heated to the set temperature shown in Table 2.

[0030]

[Table 2]

Next, a method of manufacturing the optical element, that is, the lens 2 when the optical element molding die 7 according to the present invention is used will be described according to the procedure. In this manufacturing method, each of the optical element molds 7 is to be conveyed at a tact time of 40 seconds, and each of FIGS. 5A to 5D shows each of the preheating stage 14 to the second cooling stage 17. 5 shows the state of the optical element molding die 7 in FIG. First, the preprocessed acrylic optical material 1 is stored in the cavity 3a of the optical element molding die 7, that is, in the cavity 7a surrounded by the upper die 4, the lower die 5, and the body die 6. 1
Is placed on the loading stage 11. Then, the optical element molding die 7 placed on the loading stage 11 is transported by the transport arm to the preheating stage 14 and placed thereon.

Then, in the preheating stage 14, FIG.
As shown in (a), the optical element molding die 7 is heated to the preheating temperature (190 ° C.) by the heater 18 and is pressed by the optical material 1 by the press head 19 in contact with the upper die 4 of the optical element molding die 7. A certain acrylic is pressed with a pressing force of 5 kgf or less, and the optical element molding die 7 after a predetermined time has passed is conveyed to the molding stage 15. Subsequently, in the molding stage 15, as shown in FIG. 5B, the pressing of the optical material 1 by the press head 19 in contact with the upper mold 4 of the optical element molding die 7 is performed. , Acrylic has its glass transition temperature Tg =
Since the optical material 1 is heated to a molding peak temperature exceeding 130 ° C. (200 ° C.) and reaches a molding peak temperature at which the optical material 1 can be deformed in a short time, the pressing force of the press head 19 is set to about 80 kgf. I have.

Therefore, as shown in FIG. 5B, the optical material 1 in the optical element molding die 7 placed on the molding stage 15 has the optical element transfer surfaces of the upper mold 4 and the lower mold 5, that is, Then, the optical material 1 is deformed by being pressed while being heated by the portion in contact with the lens transfer surface, and the optical material 1 eventually reaches the inner surface of the body spacer 8. However, the inner surface of the barrel spacer 8 is at a temperature about 10 to 20 ° C. lower than the lens transfer surface due to the difference in thermal conductivity between the upper mold 4 and the lower mold 5 and the barrel mold 6. Has a lower fluidity at the portion of the upper mold 4 and the lower mold 5 that are in contact with the inner surface of the barrel mold 6 than at the portion of the lower mold 5 that is in contact with the lens transfer surface. Even if there is a clearance (gap) between the portion and the body-shaped spacer 8, the optical material 1 having poor fluidity does not enter the clearance, and the molded lens 2
No burr can be generated on the outer diameter surface along the thickness direction.

After that, the optical element molding die 7 having passed for a predetermined time is moved to the first cooling stage 1 as shown in FIG.
After being conveyed to 6 and placed thereon, and pressed under a first cooling temperature (120 ° C.) lower than the glass transition point temperature Tg = 130 ° C. of acrylic as the optical material 1, the second The second cooling stage 17 is transported to and mounted on the cooling stage 17, and the second cooling stage 17 has a second cooling temperature lower than the acrylic deflection temperature Tt of 115 ° C. as shown in FIG. Pressurization at a temperature (60 ° C.) is performed.
Then, the optical element mold 3 on which the series of molding described above has been completed is conveyed and placed on the take-out stage 12, and is molded from the optical element mold 7 that has been disassembled at the take-out stage 12. The lens 2 as the completed optical element is taken out. The inventors of the present invention have investigated and found that no burr has occurred on the outer diameter surface of the lens 2.

[0035]

As described above, according to the first aspect of the present invention,
In the optical element molding die according to the above, the inner surface of the barrel die is lower in temperature than the optical element transfer surfaces of the upper die and the lower die due to the difference in the thermal conductivity between the upper die and the lower die. In such a case, since the fluidity of the optical material is worse in the portion in contact with the inner surface of the barrel mold than in the portion in contact with the optical element transfer surface, the upper mold and the lower mold Even if there is a clearance between the mold and the barrel mold, the optical material with poor fluidity does not enter the clearance and the molded optical element has no burr. Can be

Further, in the optical element molding die according to the second aspect of the present invention, the inner surface of the body spacer is changed due to the difference in the thermal conductivity of the body spacer with respect to the upper and lower dies and the body. The temperature is lower than the upper and lower optical element transfer surfaces.
Thus, similarly to the first aspect, the effect that no burr is generated in the molded optical element can be obtained. Therefore, according to the present invention, it is not necessary to perform the deburring process, and the optical element is not damaged at the time of the deburring process. Therefore, not only the yield can be improved, but also the maintenance work can be reduced. However, the effect that the cost required for manufacturing the optical element can be easily reduced is obtained.

[Brief description of the drawings]

FIG. 1 is an external perspective view illustrating a shape of an optical material according to a first embodiment.

FIG. 2 is a sectional view showing a shape of the optical element according to the first embodiment.

FIG. 3 is a cross-sectional view illustrating a structure of an optical element molding die according to the first embodiment.

FIG. 4 is a sectional view showing the structure of the optical element molding device according to the first embodiment.

FIG. 5 is a cross-sectional view showing a state of an optical element molding die at each stage of the optical element molding apparatus according to the first embodiment.

FIG. 6 is a cross-sectional view illustrating a structure of an optical element molding die according to a second embodiment.

FIG. 7 is a cross-sectional view showing the structure of an optical element molding die according to a conventional mode.

FIG. 8 is a cross-sectional view showing a shape of an optical element according to a conventional mode.

[Explanation of symbols]

 Reference Signs List 1 optical material 3 optical element molding die 3a cavity 4 upper die 5 lower die 6 trunk die 7 optical element molding die 7a cavity 8 trunk die spacer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AA03 AA21 AA28 AH74 AH76 AH78 AJ02 AM33 CA09 CB01 CK09 CK25 CK43 CK56 CL02 CL42 CN01 CQ01 CQ05

Claims (2)

[Claims] 1. An optical element molding die for molding an optical material housed in a cavity surrounded by an upper die, a lower die, and a trunk die, wherein the thermal conductivity of the upper die and the lower die is determined by the thermal conductivity of the die. The thermal conductivity of the upper and lower molds is different from the thermal conductivity of the upper mold and the lower mold, and the thermal conductivity of the upper and lower molds is H2. An optical element molding die, wherein H1 has a relationship (H1> H2) that exceeds the thermal conductivity H2 of the body mold. 2. An optical element molding die for molding an optical material housed in a cavity surrounded by an upper die, a lower die and a trunk die, wherein at least one of the upper die and the lower die is in contact with the trunk die. A trunk type spacer is interposed between the parts, and the thermal conductivity of the upper die and the lower die and the thermal conductivity of the trunk type match each other,
The thermal conductivity of the upper mold and the lower mold and the body mold and the heat conductivity of the body mold spacer are different from each other, and the heat conductivity of the upper mold and the lower mold and the body mold is H1, Assuming that the thermal conductivity of the torso spacer is H2, the thermal conductivity H1 of the upper and lower dies and the torso has a relationship exceeding the thermal conductivity H2 of the torso spacer (H1> H2). An optical element molding die characterized in that: