JPH0745331B2 - Mold for optical element molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mold used for manufacturing an optical element made of glass such as a lens and a prism by press molding a glass material.

[Prior Art] The technology of manufacturing a lens by press molding of a glass material without the need for a polishing step eliminates the complicated steps required in the conventional manufacturing of a lens, and allows a lens to be manufactured simply and inexpensively. It has become possible and has recently come to be used for manufacturing not only lenses but also optical elements made of glass such as prisms.

The properties required for the mold material used for press molding of such glass optical elements include excellent hardness, heat resistance, mold releasability and mirror surface workability. Conventionally,
As this type of mold material, many proposals have been made for metals, materials coated with metals, and the like. For example, JP-A-49-
51112 includes 13Cr martensitic steel, which is disclosed in JP-A-60-246230.
Has proposed a material obtained by coating a cemented carbide with a noble metal.

However, 13Cr martensitic steel is apt to be oxidized, and further, Fe diffuses into the glass at a high temperature and the glass is colored. Further, a material coated with a noble metal is unlikely to cause fusion, but has a defect that it is easily softened and easily deformed because it is extremely soft.

[Problems to be Solved by the Invention] In contrast to the above technique, Japanese Patent Publication No. 62-21733 discloses that a mold base material is formed of molybdenum, titanium, or tungsten, and the molding surface of the mold base material is coated with titanium nitride. It has been disclosed that an optical element excellent in specularity can be obtained for the time being. But molybdenum,
Since the hardness of titanium and tungsten is as low as Hv200-300, it has the disadvantage that the part that comes into contact with the glass is dented during repeated molding and the life of the mold is shortened. Further, although it is possible to use a cemented carbide as the die base material in the above-mentioned die, in the case of the cemented carbide, since many pores are generated, the specularity is not satisfactory. Further, as a mold using cemented carbide as a base material, in addition to the above-mentioned mold coated with titanium nitride, TiC,
There are many publicly known examples such as TiCN, TaN and TaC, but none of them are satisfactory in specularity.

Therefore, an object of the present invention is to provide an optical element molding die suitable for molding an optical element of glass, and in particular, it has excellent specularity, has suitable hardness, and causes fusion with glass at high temperature. No
Moreover, it is to provide a mold for a durable optical element that is resistant to chemical erosion by glass.

[Means for Solving the Problems] Japanese Patent Application No. 63-269600 describes a mold made of cemented carbide without a metal binder. The mold is improved to some extent by fusion with glass at high temperature, chemical erosion by glass, etc.
The hardness is also appropriate. However, when the SF8 glass is molded with the mold, the mold and the SF8 glass react with each other, but when the continuous molding is performed with the same mold, reaction precipitates are gradually deposited on the surface of the mold and the surface condition of the molded product. Adversely affect. Further, as the amount of reaction deposits increases, the surface roughness of the molding surface of the mold increases and the shape of the molding surface deteriorates. Therefore, frequent reworking to restore the surface shape of the mold is necessary. There were some drawbacks.

The present invention is an optical element in which a hard bonded body of a two-layer mixed structure which does not contain cobalt or nickel which is a binder metal of cemented carbide and has a composite carbide phase as a second phase is coated with TiN, TaN or the like. By using the molding die base material, the long life and the improvement of the mirror surface of the die are achieved.

That is, the present invention, in the optical element molding die used for press molding of the optical element, the mold base material is a cemented carbide having no metal binder, and at least the molding surface of the mold base material, TiN, TaN, Optical element molding characterized by being coated with a film of at least one nitride selected from SiN ₄ , BN, AlN, HfN, and ZrN or at least one carbide selected from TaC, SiC, and HfC It is a working type.

The metal binder-less cemented carbide has a higher indentation strength at high temperatures than a cemented carbide using a normal metal binder, and since it does not contain a metal binder, the polished surface is also a good mirror surface with small roughness. However, because of the above-mentioned drawbacks, TiN, Ta which has better oxidation resistance than the metal binderless cemented carbide on the molding surface of the mold made of the metal binderless cemented carbide.
A film such as N is coated. For example, the fact that TiN and TaC have better oxidation resistance than WC, which is the main component of ordinary cemented carbide,
It is also clear from the results of thermogravimetric analysis in an oxygen atmosphere shown in the figure (TiN), FIG. 10 (WC), and FIG. 11 (TaC). Also, as a coating material having better oxidation resistance than WC other than TiN and TaC, nitrides such as TaN, Si ₃ N ₄ , BN, AlN, HfN, and ZrN, and Si
The presence of carbides such as C and HfC has also been found from the results of thermogravimetric analysis in an oxygen atmosphere.

In order to produce the mold base material used in the present invention, for example, WC powder is used as the first component, and TiC powder or solid solution powder of TiC and WC (TiC / WC = 3/7) is used as the second component. On the other hand, it is wet-mixed with a ball mill or an attritor, dried, and then pressure-molded into a desired shape at about 1 t to 10 t / cm ² .

Next, after sintering the obtained mixed powder compact at high temperature,
A shape base material is obtained by processing into a shape corresponding to the shape of the final optical element.

Sintering temperature is higher than ordinary WC-Co cemented carbide by 200 ° C or more and 1550 ° C or more and 2550 ° C or less, and sintering is performed in a non-oxidizing atmosphere. The desirable mixing ratio of WC and TiC is 70 to 99% by weight of WC and 1 to 30% by weight of TiC.

Here, the meaning of adding TiC is to densify the structure. That is, if the amount of TiC is less than 1% by weight, the sinterability becomes poor, and if it exceeds 30% by weight, the sinterability becomes poor, and the obtained crystal grains are apt to become coarse, and a gap can be formed at the grain boundary.

When WC powder and TiC powder are used as the raw material powder, the first phase of WC and a part of WC form a solid solution with TiC during sintering and are represented by (Ti, W) C (NaCl type crystal). It constitutes the second phase of the compound carbide. The solid solution limit of WC in the double carbide at the sintering temperature is about 70% by weight. Therefore, the microstructure after sintering is 96.7% WC for the first phase when the raw material powder is 99% by weight WC and 1% by weight TiC.
% By weight, (Ti, W) C in the second phase is 3.3% by weight, and when the raw material powder is 70% by weight in W and 30% by weight in TiC, WC in the first phase is 0% by weight, (Ti, W) in the second phase C becomes 100% by weight.

In addition, as a second component, a part of TiC powder is used as IV b, V b,
It is also possible to use a solid solution double carbide powder in which one or more kinds of transition metals belonging to VIb group are substituted with carbides or nitrides.

For example, when TaC is used as a part of the second component in order to improve heat resistance, the second phase after sintering becomes a (Ti, Ta, W) C ternary compound carbide.

The die base material thus obtained is mirror-polished into a shape corresponding to a desired optical element, and after cleaning, it is cleaned with an ion bombardment in a film forming apparatus, and then the molding surface of the die base material is subjected to an ion plating method and sputtering. Ti by law
The optical element molding die of the present invention can be obtained by forming a film of N, TaN or the like on the order of 0.5 to 3 μm.

It is preferable to provide an intermediate layer of metal Ti or the like between the mold base material and a film of TiN or the like for improving the adhesion.

Metallic Ti has high reactivity, and it is compatible with metal binderless cemented carbide.
It has the effect of increasing the adhesion of TiN and relaxing the compressive stress of the film. Further, the purpose of providing the intermediate layer is to prevent the peeling of the film by lowering the reactivity and film stress of the TiN layer and the like and the metal binderless cemented carbide, and therefore other active metals such as Cr and Ni. Has the same effect. In such a mold, a metal Ti layer or the like is formed as an intermediate layer to a thickness of about 0.1 to 0.5 μm and a TiN layer or the like is formed to a thickness of about 0.5 to 3 μm on the molding surface of the mold base material by an ion plating method or a sputtering method. Obtained.

Further, for example, in the case of a mold coated with a TiN layer, a so-called graded film in which the composition on the mold base material side is metallic Ti and N gradually increases toward the TiN layer so that the composition on the TiN layer side becomes TiN By providing it as the intermediate layer, abrupt stress change between the intermediate layer and the TiN layer is eliminated, and peeling of the film can be further prevented.

[Examples] Specific examples of the present invention will be described below with reference to the drawings.

Example 1 FIGS. 1 and 2 show an optical element molding die 1 according to the present invention.
2 illustrates one embodiment.

FIG. 1 shows a state before press molding of the optical element, and FIG. 2 shows a state after molding the optical element. In FIG. 1, 1 and 2 are mold base materials, 1-a and 2-a are TaN films formed on a molding surface of the mold base material in contact with the glass material, 3 is a glass material, and 2
In the figure, 4 is an optical element.

By pressing the glass material 3 placed between the molds as shown in FIG. 1, the optical element 4 such as a lens is molded as shown in FIG.

Preparation of mold base material Three kinds of mixed powders were prepared by changing the mixing ratio of WC powder and TiC powder. Table 1 shows the respective mixing ratios.

These mixed powders were press-molded into a predetermined shape, sintered at 1550 ° C. in vacuum, and then mirror-finished into a shape corresponding to the shape of the optical element to form a die base material.

Preparation of Tantalum Nitride (TaN) Coating Mold [FIG. 3] FIG. 3 is a schematic configuration diagram showing an ion plating apparatus for forming a TaN layer. In FIG. 3, 6 is a vacuum chamber. An exhaust port 7 is connected to the vacuum chamber, and the exhaust port is connected to an exhaust system including a decompression source (not shown). A heater 8 is arranged in the upper part of the vacuum chamber 6.
A vapor deposition film thickness monitor 9 and a die base material support 10 are disposed below the heater 8, and an appropriate number of die base materials 12 are supported on the support with the film forming surface facing downward. Reference numeral 14 is a bias power source for applying a bias voltage to the die base material.
The die base material support 10 can be rotated around a rotation center 10a in the vertical direction, and the rotation is driven by drive means (not shown).

On the other hand, in the lower part of the vacuum chamber 6, an electron gun 18 as an evaporating means containing a vapor deposition material (Ta) 16 is arranged. Above the electron gun is an ionization electrode for the ionization of the evaporation material.
20 is located, and 22 and 24 are its power source and cooling water circulation means, respectively. A shutter above the ionization electrode 20.
26 is disposed, and the shutter is rotated by a driving device (not shown) outside the vacuum chamber 2 so that the path between the electron gun 18 and the mold base material support 10 can be blocked at appropriate times.

An ion gun 28, which is a reaction gas (nitrogen gas) ionization means, is also disposed in the vacuum chamber 6. The outer ion gun includes a reaction gas discharge part and an electrode for ionizing the reaction gas discharged from the discharge part. 30 is a pipe for supplying reaction gas to the reaction gas discharge part of the ion gun,
Reference numeral 32 is a cooling water circulating means for the ion gun.

FIG. 4 is a schematic configuration diagram showing another ion plating apparatus. 4, the same members as those in FIG. 3 are designated by the same reference numerals. The apparatus shown in FIG. 4 differs from the apparatus shown in FIG. 3 only in the structure of the power supply unit for applying a voltage to the mold base material 12. That is, the DC power supply 14 of the apparatus of FIG.
Instead of the high frequency power supply 34 and the matching circuit in the device of FIG.
36 and are used. The TaN layer similar to that of the device shown in FIG. 3 is formed by using the device of FIG.

When forming the TaN layer, the mold base material 1 finished to the specified accuracy
2 was washed with an organic solvent and then supported by the mold base material support 10. Next, the inside of the vacuum chamber 6 was evacuated to 1 × 10 ⁻⁵ torr or less, and the die base material 12 was heated to about 300 ° C. by the heater 8. Ar gas is introduced into the ion gun to a vacuum degree of 3 × 10 ⁻⁴ torr, and cleaning is performed for 10 minutes by ion bombardment of the mold surface under conditions of a discharge voltage of about 250 V and a discharge current of about 1.3 A. Next, a positive bias voltage of 50 V was applied to the ionization electrode 20, and the vapor deposition material Ta16 was vapor-deposited by the electron gun 18 to a thickness of 0.2 μm. At the same time, nitrogen gas was introduced into the vacuum chamber 6 from the ion gun 28 at a flow rate of 70 sccm to a vacuum degree of 5 × 10 ⁻⁴ torr and tantalum (T
a) A TaN film was continuously formed on the film. The film thickness monitor 8 was used to monitor the film forming speed and the film thickness. Deposition rate is about 2Å / sec
Met. The vapor deposition was stopped when the 1 μm thick TaN layer was formed.

Although the ion plating method is used as the method for forming the TaN layer in the above-described embodiment, the TaN layer can be formed by using another method, for example, a reactive sputtering method.

FIG. 5 is a schematic configuration diagram of a reactive sputtering apparatus for forming a TaN layer. In FIG. 5, 34 is a vacuum chamber. An exhaust port 35 is connected to the vacuum chamber, and the exhaust port is connected to a decompression source (not shown). A heater 36 is arranged in the upper part of the vacuum chamber 34, and 37 is a power source thereof.
A mold base material support 38 is disposed below the heater 36,
The die base material 39 is supported on the support with the molding surface facing downward. 40 is a bias power source for applying a bias voltage to the die base material. A coil 41 for generating glow discharge is arranged below the die base material 40, 42 is a high-frequency power source for the glow discharge, and 43 is a matching circuit. A cathode electrode 44 is arranged in the lower part of the vacuum chamber 34, and a Ta electrode is formed on the electrode.
The target 45 is arranged. 46 is a power supply for applying a voltage to the cathode electrode 44. 47 is a pipe for supplying argon gas toward the Ta target 45, and 48 is a pipe for supplying nitrogen gas and / or ammonia gas toward the die base material 39. .

When forming the TaN layer, the mold base material 3 is finished to the specified accuracy.
After cleaning 9 with an organic solvent, it is supported by a mold base material support 38. Next, the vacuum chamber 34 is evacuated to a predetermined degree of vacuum, argon gas is introduced from the pipe 47, and a high frequency voltage is applied to the coil 41 by a high frequency power source to generate glow discharge,
Further, a negative voltage is applied to the mold base material 39 by the bias power source 40 to perform sputter cleaning of the mold base material 39 with argon ions. After that, a high frequency or DC voltage is applied to the cathode electrode 44 by the power source 46 to generate a glow discharge of argon in the vicinity of the Ta target 45, and the Ta target is bombarded with argon ions. / Or ammonia gas is introduced, a high frequency voltage is applied to the coil 41 by the power supply 42 to form nitrogen plasma, and a negative bias voltage is applied to the mold base material 39 by the bias power supply 40 to generate nitrogen plasma in the nitrogen plasma. Reactive sputtering of Ta can be performed by drawing ions toward the mold base material 38. As a result, a TaN layer is formed on the surface of the mold base material 39.

Molding of Lens with TaN Coated Molding Mold Next, an example in which a glass lens is press-molded with the optical element molding mold of the present invention will be described in detail. As a comparison
A mold of a conventional cemented carbide mold base consisting of WC (90%) + Co (10%) coated with TaN (Comparative Example 1), a mold base mold of molybdenum coated with TaN (Comparative Example 2) Was used.

The lens forming apparatus used is shown in FIG.

In FIG. 6, 51 is a vacuum chamber main body, 52 is a lid thereof, 53 is an upper mold for molding an optical element, 54 is a lower mold thereof, 55 is an upper mold holder for holding an upper mold, and 56 is a body mold. , 57 is a mold holder, 58
Is a heater, 59 is a lifting rod that lifts the lower die, 60 is an air cylinder that operates the lifting rod, 61 is an oil rotary pump,
62, 63 and 64 are valves, 65 is an inert gas inflow pipe, 66 is a valve, 67 is a leak pipe, 68 is a valve, 69 is a temperature sensor, 70 is a water cooling pipe, and 71 is a stand for supporting a vacuum chamber.

The process of manufacturing the lens will be described below. Flint optical glass SF14 (transition point Tg = 485 ° C, softening point Sp = 586 ° C) is made spherical and the glass material adjusted to a predetermined amount is put into the mold cavity.

After placing the mold into which the glass material was placed in the equipment, vacuum chamber
The lid 52 of 51 is closed, water is flowed through the water cooling pipe 70, and the heater 58
Pass a current through. At this time, the nitrogen gas valves 66 and 68 are closed, and the exhaust system valves 62, 63 and 64 are also closed. The oil rotary pump 61 is always rotating.

Open the valve 62 and start evacuation. When it becomes 10 ^-2 Torr or less, close the valve 62 and open the valve 66 to introduce nitrogen gas into the vacuum chamber from the cylinder. Air cylinder when the temperature reaches a certain level
Activate 60 and pressurize at a pressure of 10 kg / cm ² for 5 minutes. After removing the pressure, the cooling rate is −5 ° C./min until the temperature reaches the dislocation point or lower. After that, cooling is performed at a rate of −20 ° C./min or higher, and when the temperature drops to 200 ° C. or lower, the valve 66 is closed. The leak valve 63 is opened to introduce air into the vacuum chamber 51. Then, the lid 52 is opened, the upper die is removed, and the molded product is taken out.

As described above, the lens was molded using the Freton optical glass SF14. FIG. 7 shows a molding condition at this time, that is, a time-temperature relationship diagram.

The press molding as described above was repeated 200 times to examine the deformation of the mold. For the deformation of the mold, the amount of depression in the center was measured with an interferometer. In addition, the specularity of the mold and the molded product is
200), the number of surface defects in an area of 100 μm × 100 μm was examined and evaluated. It should be noted that a pinhole is used as a surface defect in a mold and a protrusion is used as a molded product in a molded product. The results are shown in Table 2.

As is clear from the results shown in Table 2, the center part of the mold using molybdenum as the base material was deformed, and the mold using the cemented carbide as the base material was not deformed, but the mold surface had defects. It was transferred to a molded product and protrusions were generated on the surface.

Example 2 Tantalum carbide (TaC) was prepared in the same manner as in Example 1 except that methane gas was used as the reaction gas instead of nitrogen gas by the ion plating apparatus shown in FIG. 3 on the same mold base material as in Example 1. ) Layers were formed. Using the mold thus obtained, press molding was performed in the same manner as in Example 1 to evaluate the deformation of the mold and the specularity of the mold and the molded product. The results are shown in Table 3.

As is clear from the results in Table 3, the mold of the present invention was not deformed, and the mirror surface properties of the mold and the molded product were good.

Example 3 Preparation of mold base material In addition to WC powder and TiC powder, various mixed powders were prepared using WC powder, TaC powder, HfN powder and the like. Table 4 shows the respective mixing ratios.

These mixed powders were press-molded into a predetermined shape, sintered at 1550 ° C. in vacuum, and then mirror-finished into a shape corresponding to the shape of the optical element to form a die base material.

Preparation of Titanium Nitride (TiN) Coating Mold A TiN layer was formed by the ion plating apparatus shown in FIG. However, the vapor deposition material (Ta) 16 used in Example 1
I chose Ti.

First, the mold base material 12 finished to a predetermined accuracy was washed with an organic solvent and then supported by the mold base material support 10. Next, the inside of the vacuum chamber 6 was evacuated to 1 × 10 ⁻⁵ torr or less, and the die base material 12 was heated to about 300 ° C. by the heater 8. Ar to ion gun
Gas is introduced up to a vacuum degree of 3 × 10 ^-4 torr and the discharge voltage is about 250.
The mold surface is cleaned by ion bombardment for 10 minutes under conditions of V and discharge current of about 1.3A. Next, a positive bias voltage of 40 V was applied to the ionization electrode 20, and the vapor deposition material Ti16 was vapor-deposited by the electron gun 18 to a thickness of 0.2 μm. Similarly, nitrogen gas was introduced from the ion gun 28 into the vacuum chamber 6 at a flow rate of 70 sccm to a vacuum degree of 5 × 10 ⁻⁴ torr, and Ti was continuously formed on the titanium (Ti) film.
An N film was formed. The film thickness monitor 8 was used to monitor the film forming speed and the film thickness. The film formation rate was about 10Å / sec. 1 μm thick
The vapor deposition was stopped when the TiN layer was formed.

Molding of lens with TiN coated molding die Next, an example in which a glass lens is press-molded with the optical element molding die of the present invention will be described in detail. As a comparison
A mold made of a conventional cemented carbide alloy consisting of WC (90%) + Co (10%) coated with TiN (Comparative Example 3), and a mold matrix made of molybdenum coated with TiN (Comparative Example 4) Was used.

The continuous molding apparatus used is shown in FIG.

In FIG. 8, 104 is an intake substitution chamber, 106 is a forming chamber, 108 is a vapor deposition chamber, and 110 is an ejection substitution chamber. Reference numerals 112, 114, and 116 are gate valves, 118 is a rail, and 120 is a pallet that can be conveyed on the rail in the direction of arrow A. Reference numerals 124, 138, 140 and 150 are cylinders, and 126 and 152 are valves. A heater 128 is arranged along the rail 118 in the molding chamber 106.

Inside the molding chamber 106, a heating zone 106-1, a press zone 106-2, and a slow cooling zone 106-in order along the pallet conveying direction.
It is said to be 3. At the lower end of the rod 134 of the cylinder 138 in the press zone 106-2, the upper mold member 130 for molding is formed.
Is fixed, and a lower molding die member 132 is fixed to the upper end of the rod 136 of the cylinder 140. The upper mold member 130 and the lower mold member 132 are the mold members according to the present invention shown in FIG. In the vapor deposition chamber 108, a container 142 containing a vapor deposition substance 146 and a heater 144 for heating the container 142.
Are arranged.

Flint optical glass (SF14, softening point Sp = 586 ° C., glass transition point Tg = 485 ° C.) was roughly processed into a predetermined shape and size to obtain a blank for molding.

Place the glass blank on the pallet 120 and take in the replacement chamber 1
Put the pallet at the position 120-1 in 04 and push the pallet at that position in the direction A by the rod 122 of the cylinder 124 to move the gate valve.
Transported over 112 to the position 120-2 in the molding chamber 106,
In the same manner, new intake and replacement chambers will be sequentially added at the specified timing.
Put the pallet in 104, and form the pallet each time in the molding room 1
It was transported to the position of 120-2 → …… → 120-8 in 06 in order. In the meantime, in the heating zone 106-1, the glass blank is gradually heated by the heater 128 to reach the softening point or higher at the position 120-4, and then conveyed to the press zone 160-2, where the cylinders 138 and 140 are operated. By pressing the upper mold member 130 and the lower mold member 132 at a pressure of 10 kg / cm ² for 5 minutes, then releasing the applied pressure and cooling to below the glass transition point, and then operating the cylinders 138 and 140 to operate the upper mold member 130 and the lower mold member. Mold member
132 was released from the glass molding. At the time of the pressing, the pallet was used as a body member for molding. Then, in the cooling zone 106-3, the glass molded product was gradually cooled. The interior of the molding chamber 106 was filled with an inert gas.

The pallet that has reached the position 120-8 in the forming chamber 106 is transferred to the position 120-9 in the vapor deposition chamber 108 over the gate valve 114 in the next transfer. Usually, vacuum deposition is performed here, but this deposition was not performed in this embodiment. Then, in the next transportation, the material was transported over the gate valve 116 to the position 120-10 in the take-out replacement chamber 110. Then, at the time of the next conveyance, the cylinder 150 is operated to operate the rod 148.
Then, the glass molded product was taken out of the molding apparatus 102.

Repeat the above press molding 10,000 times,
The deformation of the mold was investigated. For the deformation of the mold, the amount of depression in the center was measured with an interferometer. For the specularity of the mold and the molded product, the degree of surface defects was examined with an optical microscope (× 200). The results are shown in Table 5.

As is clear from the results in Table 5, the center part of the mold using molybdenum as the base material was greatly deformed by 2λ, and the center part of the mold using cemented carbide as the base material was deformed by λ / 2. There was a defect on the surface, which was transferred to the molded product and a protrusion was generated on the surface.

[Effect of the Invention] According to the molding die of the present invention, since there are no defects such as pinholes on the surface of the mold, defects such as protrusions do not occur on the molded product, and the mold does not deform even after repeated use.

[Brief description of drawings]

1 and 2 are sectional views showing one embodiment of an optical element molding die according to the present invention. FIG. 1 shows a state before press molding, and FIG. 2 shows a state after press molding. 3, 4 and 5 are schematic views showing a film forming apparatus used in the present invention. FIGS. 3 and 4 show an ion plating apparatus and FIG. 5 shows a reactive sputtering apparatus. FIGS. 6 and 8 are sectional views showing a lens molding apparatus using a molding die for an optical element according to the present invention. FIG. 6 is a discontinuous molding type and FIG. 8 is a continuous molding type. FIG. 7 is a time-temperature relationship diagram when molding a lens. FIG. 9 is a thermogravimetric analysis chart of TiN, FIG. 10 is a thermogravimetric analysis chart of WC, and FIG. 11 is a thermogravimetric analysis chart of TaC. 1,2 ... Mold base material, 1-a, 2-a ... TiN film, 3 ... Glass material, 4 ... Molded lens, 6 ... Vacuum chamber, 8 ... Heater, 10 ... Mold Base material support, 12 …… type base material, 16 …… evaporation material, 18 …… electron gun, 20 …… ionization electrode, 28 …… ion gun, 34 …… vacuum chamber, 35 …… exhaust port, 36 …… Heater, 37 ... Heater power supply, 38 ... Mold base material support, 39 ... Mold base material, 40 ... Bias power supply, 41 ... Glow discharge generating coil, 42 ... High frequency power supply, 43 ... Matching circuit , 44 …… Cathode electrode, 45 …… Ta target, 46 …… Cathode power supply, 47 …… Argon gas supply pipe, 48 …… Nitrogen gas, ammonia gas supply pipe, 51 …… Vacuum chamber body, 52 …… Lid, 53 …… Upper mold, 54 …… Lower mold, 55 …… Upper mold hold, 56 …… Body mold, 57 …… Mold holder, 58 …… Heater, 59 …… Raising rod, 60 …… Air cylinder, 61 …… Oil rotary pump, 62,63,64 …… Valve, 65 …… Inflow pipe, 66 …… Valve, 67 …… Outflow pipe, 68 …… Valve, 69 …… Temperature sensor, 70 …… Water cooling pipe, 71 …… Table, 102 …… Molding device, 104 …… Injection displacement chamber, 106 …… Molding chamber, 108 …… Deposition chamber, 110 …… Extraction chamber, 112 …… Gate valve, 114 …… Gate valve, 116 …… Gate valve, 118 …… Rail, 120 …… Pallet, 122 …… Rod, 124 …… Cylinder, 126 …… Valve, 128 …… Heater, 130 …… Upper mold, 132 …… Lower mold, 134… … Rod, 136 …… Load, 138 …… Cylinder, 140 …… Cylinder, 142 …… Container, 144 …… Heater, 146 …… Evaporation material, 148 …… Rod, 150 …… Schilling, 152 …… Valve.

Claims (2)

[Claims] 1. An optical element molding die used for press molding of an optical element, wherein the die base material is a cemented carbide having no metal binder, and at least the forming surface of the die base material,
At least one nitride selected from TiN, TaN, Si ₃ N ₄ , BN, AlN, HfN, ZrN or at least one carbide selected from TaC, SiC, HfC is coated. Characteristic optical element molding die. 2. The composition of the cemented carbide is WC-Ti (C, N) system or W.
The optical element molding die according to claim 1, which is a C-Ti (C, N) -TaC system.