JP2002226230A - Forming mold for optic ang its producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing a mold capable of transferring precisely a shape in the case an optical having the shape of a free curved face not realized in the conventional grinding works is press-molded repeatedly regardless of any molding condition or any kind of glass seed. SOLUTION: The forming mold for the optic has a transferring face to shape the optic on a part of a base material 11. A layer 12 for cutting work the main component of which is a metal is formed on the base material 11 by a gas deposition method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for manufacturing optical elements made of glass, such as lenses and prisms, with high precision by press-molding a glass material, and a method of manufacturing the same.

[0002]

2. Description of the Related Art The technology of manufacturing a lens by press molding a glass material without the need for a polishing step eliminates the complicated steps required in conventional manufacturing, making it possible to manufacture a lens simply and inexpensively. In recent years, it has come to be used for manufacturing not only lenses but also optical elements made of prisms and other glasses.

The properties required of a mold used for press molding of such a glass optical element include hardness,
It is excellent in oxidation resistance, heat resistance, mold release properties, mirror workability and the like. Heretofore, many proposals have been made such as metal, ceramics, and materials coated with them as this type of mold material. If name a few examples, 13Cr martensitic steels in JP-A-49-51112 is, Japanese Patent Publication No. Sho 52-45613 is SiC and Si ₃ N _4, Sho 59-121126 JP Has Ti
A mixed material of C and a metal is disclosed in Japanese Patent Application Laid-Open No. 60-246230.
Also, JP-A-61-183134 and JP-A-61-183134
JP-A-281030 and JP-A-1-301864 propose a material coated with a diamond thin film or diamond-like carbon film, and JP-A-64-83529 proposes a material coated with a hard carbon film.

[0004]

However, no conventional mold material has been obtained which satisfies all of hardness, oxidation resistance, heat resistance, mold release property and mirror workability.

[0005] For example, 13 martensitic steel has a disadvantage that it is easily oxidized, and further, Fe diffuses into the glass at a high temperature to color the glass.

Further, SiC, Si_ThreeN_Four, TiC, diamond
Mondo thin film, diamond-like carbon film, hard carbon film
Although the hardness of the material is very high and the mechanical strength is excellent,
Poor workability, difficult to process into high-precision mold
is there. Further, SiC, Si _ThreeN_Four, TiC, at high temperature
Oxidation occurs and fusion of the glass occurs.

In a mold in which a noble metal thin film, a diamond thin film, a diamond-like carbon film, and a hard carbon film are coated on a cemented carbide base material, a method of machining a cemented carbide using a diamond grindstone may be used. Although it is general, it has a drawback that it cannot be processed into a spherical surface or a free-form surface with a small curvature. The free-form surface here means
This is a surface including a non-axisymmetric aspheric surface.

As a measure for improvement, a cutting layer which can be easily machined on a cemented carbide base material is disclosed in
No. 23230, an electroless Ni-P plating film, and JP-A-7-41326, a ternary alloy containing P (P-N
i, Co, Fe-Si, Ti, Cu, Zr, Nb, M
o, Ru, Rh, Pd, Hf, Ta, W, Re, Os,
A method has been proposed in which Ir) is sputter-deposited, the cut layer is cut with a diamond bite to form a transfer surface, and a noble metal-based alloy thin film is sputter-deposited on the cut layer. .

However, an electroless Ni-P plating film cannot be formed on a superhard material to a thickness of 10 μm or more, and does not have sufficient adhesion. There are disadvantages in that a crack is generated in the cutting layer and the base material and the cutting layer are separated.

[0010] In the case of forming a ternary alloy by sputtering for the cutting layer, it is necessary to increase the distance between the target and the base material in order to uniformly form a sputter film on the base material processed into a shape approximate to a free-form surface. In this case, the film forming speed is reduced to 50 μm
There is a disadvantage that it takes an extremely long time to form a film.

Furthermore, in vacuum film formation such as sputtering, it is not possible to form a film selectively, so that the film extends around the side surface of the mold base material, so that the mold can be covered with a high-precision jig or formed. The side face had to be post-processed after the film. In addition, a large amount of metal having the same composition as that of the cut layer is deposited on the inner wall surface of the sputtering apparatus other than the intended optical element molding die, and there is a problem in terms of resource saving and effective use of resources.

Further, when an optical component such as a polyhedral prism is manufactured by an optical element molding die using the above-mentioned cutting layer, if the shape does not include a diamond bite, an integrated die for a polyhedral prism cannot be processed. Sometimes you had to use a type. However, in the split type,
There are problems that it is difficult to ensure the positional accuracy of the polyhedron, that glass enters into the gap between the dies, that the glass is broken, and that the shape transfer accuracy is reduced.

The present invention solves such a conventional problem,
Efficiently manufacture molds that can accurately transfer the shape of optical elements with free-form surfaces that could not be achieved by conventional grinding, regardless of the molding conditions and glass type, even after repeated press molding. The purpose is to provide a way to:

[0014]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, the optical element molding die according to the present invention is an optical element molding die having a transfer surface for molding an optical element on a part of the base material, and on the base material, A cutting layer mainly composed of a metal is formed by a gas deposition method.

Further, in the optical element molding die according to the present invention, the base material is tungsten carbide (WC).
Consisting of a cemented carbide having as a main component, the cutting layer,
An alloy of one type selected from nickel (Ni), cobalt (Co), and iron (Fe) and phosphorus (P); and copper (C)
u), silicon (Si), titanium (Ti), chromium (C
r), zirconium (Zr), niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (T
a), one of ternary alloys selected from tungsten (W).

In the mold for molding an optical element according to the present invention, an underlayer mainly composed of a metal is formed on the base material by a sputtering method, and then the cut layer mainly composed of a metal is formed. It is characterized by being formed by a gas deposition method.

In the optical element molding die according to the present invention, the base material may be tungsten carbide (WC).
And the underlayer and the cutting layer are made of nickel (Ni), cobalt (Co),
An alloy of one type selected from iron (Fe) and phosphorus (P), copper (Cu), silicon (Si), titanium (Ti),
Chromium (Cr), zirconium (Zr), niobium (N
b), a ternary alloy of one selected from molybdenum (Mo), hafnium (Hf), tantalum (Ta), and tungsten (W).

Also, in the optical element molding die according to the present invention, the transfer surface is a free-form surface.

The optical element molding die according to the present invention is characterized in that the thickness of the cut layer is 50 μm or more.

Further, a method of manufacturing an optical element molding die according to the present invention is a method of manufacturing an optical element molding die having a transfer surface for molding an optical element on a part of a base material, A cutting layer mainly composed of a metal is formed on a base material by a gas deposition method.

In the method of manufacturing an optical element molding die according to the present invention, an underlayer mainly composed of a metal is formed on the base material by a sputtering method, and then the cutting layer mainly composed of a metal is formed. It is characterized in that the processing layer is formed by a gas deposition method.

Further, in the method for manufacturing an optical element molding die according to the present invention, nickel (Ni), cobalt (C
o), one type selected from iron (Fe) and phosphorus (P)
And a chamber for producing ultrafine particles of an alloy of niobium (Nb), molybdenum (Mo), hafnium (Hf), and tantalum (Ta)
It is characterized in that the cutting layer is formed by a gas deposition method by separately using one type of ultrafine particle generation chamber selected from tungsten (W).

Further, a method of manufacturing an optical element molding die according to the present invention is a method of manufacturing an optical element molding die having a transfer surface for molding an optical element on a part of a base material, After forming a cutting layer mainly composed of a metal on the base material by a gas deposition method, the cutting layer is cut into a desired shape and uniformly polished. In the case of a film, a surface layer is formed by ion beam evaporation, and in the case of a noble metal alloy thin film, a surface layer is formed by sputtering.

In the method of manufacturing an optical element molding die according to the present invention, an underlayer mainly composed of a metal is formed between the base material and the cut layer by a sputtering method. .

In the method for manufacturing an optical element molding die according to the present invention, an intermediate layer made of a metal carbide, nitride, or carbonitride is formed between the cut layer and the surface layer. It is characterized by:

Further, a method of manufacturing an optical element molding die according to the present invention is a method of manufacturing an optical element molding die having a transfer surface for molding an optical element on a part of a base material, A step of processing the base material into a shape approximate to the minus tolerance of the desired shape, and forming a shape forming layer mainly composed of a metal by a gas deposition method according to a difference between the approximate shape of the base material and a desired shape. A step of forming a film with high precision, a step of uniformly polishing the shape forming layer, and a step of forming a surface layer on the shape forming layer by ion beam evaporation for a hard carbon film and sputtering for a noble metal-based alloy thin film And a step of performing

Further, the method for manufacturing an optical element molding die according to the present invention further comprises a step of forming an underlayer mainly composed of a metal between the base material and the shape forming layer by a sputtering method. It is characterized by:

Further, in the method of manufacturing an optical element molding die according to the present invention, the base material is made of a cemented carbide mainly containing tungsten carbide (WC), and the underlayer and the shape forming layer are An alloy of one selected from nickel (Ni), cobalt (Co), and iron (Fe) and phosphorus (P), and copper (Cu), silicon (Si), titanium (Ti), chromium (Cr), Zirconium (Zr),
Niobium (Nb), molybdenum (Mo), hafnium (H
f), one of ternary alloys selected from tantalum (Ta) and tungsten (W).

In the method of manufacturing an optical element molding die according to the present invention, an intermediate layer made of a metal carbide, nitride, or carbonitride is formed between the shape forming layer and the surface layer. It is characterized by further comprising a step.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described.

In the present embodiment, a molding die having a transfer surface for molding an optical element on a part of a base material, wherein a cutting layer mainly composed of a metal formed on the base material is formed. In the method for manufacturing an optical element molding die having a cutting layer, a cutting layer is formed by a gas deposition method.

The base material is a cemented carbide mainly composed of tungsten carbide (WC). The underlayer and the cutting layer are made of nickel (Ni), cobalt (Co), iron (Fe).
Alloy of phosphorus (P) and copper (C)
u), silicon (Si), titanium (Ti), chromium (C
r), zirconium (Zr), niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (T
a), a ternary alloy with one selected from tungsten (W).

Further, in the method of manufacturing a mold for forming an optical element, there is provided a method for manufacturing nickel (Ni), cobalt (Co), iron (Fe).
And a chamber for generating ultrafine particles of an alloy of phosphorus (P) and one selected from the group consisting of niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (Ta), and tungsten (W) It is desirable to form a cutting layer by a gas deposition method using two types of ultrafine particle generation chambers.

Further, as a method of manufacturing a new optical element molding die which does not perform a cutting process, a molding die having a transfer surface for molding an optical element on a part of a base material, wherein the base material is desirably used. And forming a shape-forming layer mainly composed of a metal corresponding to the difference between the approximate shape of the base material and the desired shape with high precision by a gas deposition method. A step of forming a film, a step of uniformly polishing the shape-forming layer, and a step of forming a surface layer on the shape-forming layer by ion beam evaporation in the case of a hard carbon film or by sputtering in the case of a noble metal-based alloy thin film. .

The operation of the present embodiment configured as described above will be described.

In the gas deposition method, an ultrafine particle generation chamber,
It is composed of a film forming chamber and a transport pipe.In the ultra-fine particle generation chamber, the metal ultrafine particles generated by arc, resistance heating, etc. in an inert gas atmosphere are guided to the film forming chamber through the transport pipe by a pressure difference, and high-speed A dry film forming method for directly drawing a pattern by spraying is disclosed in Japanese Patent Application Laid-Open No. 60-106.
964.

The following is a description of the characteristics in the case where a cut layer mainly containing a metal is formed by the gas deposition method.

In the gas deposition method, the differential pressure, the substrate temperature,
By changing the gas type and the like, the particle size, packing, density, and the like of the formed ultrafine particle film can be changed, and an ultrafine powder as an aggregate thereof can be formed. These are factors that affect the machinability and mold durability of the cut layer, and therefore, these characteristics can be controlled by optimizing the film forming conditions.

In addition, since the gas deposition method basically uses all raw materials that have become ultrafine particles,
Material utilization efficiency is very good. On the other hand, the material use efficiency of the sputtering method or the vacuum evaporation method is about 5% at best.

FIG. 1 is a schematic sectional view of the optical element molding die of the present embodiment. In FIG. 1, 11 is a mold base material, 12 is a cutting layer, and 13 is a release layer. Further, as shown in FIG. 2, an intermediate layer 23 may be introduced between the cutting layer 22 and the release layer 24. Although FIG. 1 shows a concave free-form prism forming die, the present invention is not limited to a concave free-form prism forming die, but includes a convex forming die and an aspheric lens forming die. It can also be used for cylindrical lens molding dies and the like.

When a cut layer is formed on such an optical element molding die by sputtering, the side surface other than the molding surface is also
An extra metal film is formed due to the influence of the wraparound. Therefore, the sputtering method requires a high-precision jig during film formation and post-processing after film formation, which increases the number of steps.However, since the gas deposition method is direct drawing, metal is mainly used at an arbitrary location. A cutting layer as a component can be formed. For this reason,
This greatly contributes to a reduction in the number of processes and cost reduction. Also, in particular, since the film formation range can be limited by the conditions such as the nozzle shape and the distance between the nozzle and the substrate, a cutting layer is formed only on a desired surface of the mold base material to prevent wraparound to the side surface. It is also possible.

The cutting layer used in the present embodiment is made of nickel (Ni), cobalt (Co), iron (F) from the viewpoint of workability with a diamond tool and hardness during molding.
e) an alloy of one selected from the group consisting of phosphorus (P), copper (Cu), silicon (Si), titanium (Ti), chromium (Cr), zirconium (Zr), niobium (Nb), and molybdenum ( Mo), hafnium (Hf), tantalum (T
a), it is preferably a ternary alloy with one type selected from tungsten (W).

FIG. 3 is a schematic diagram of a gas deposition film forming apparatus used in the present embodiment. In this gas deposition film forming apparatus, first, a substance such as a metal (this is referred to as an evaporation material A) in an atmosphere of an inert gas in the ultrafine particle generation chamber 31.
As a heating and evaporating device, a plasma torch 33 connected to a plasma arc power supply 32 is provided, and a water-cooled copper hearth 34 in which an evaporating material A is stored on the upper surface is provided to face the plasma torch 33. The vapor of the metal evaporated into ultra-fine particles (aerosol-like) by this heating and evaporating device is converted into a water-cooled copper hearth 3
4 is sucked by a transfer pipe 36 provided with an ultrafine particle gas inlet 35 directly above the transfer pipe 4, transferred to a film formation chamber 37 as shown by an arrow a in FIG. From the nozzle 38 attached to the tip, the ultrafine particles are sprayed at a high speed onto the mold base material 39 immediately below and deposited on the mold base material to form a metal film.

Although not shown in the drawing, the mold base material 39 has a structure in which a heating mechanism using a heater and an XYZθφ stage can be connected as necessary. Similarly, the inert gas in the ultrafine particle generation chamber 31 is introduced by a gas introduction pipe connected thereto, and the film formation chamber 37 is evacuated by a vacuum pump connected thereto through an exhaust pipe provided with a valve. As a result, a constant pressure difference is generated between the ultrafine particle generation chamber 31 and the film formation chamber 37, so that the inert gas introduced into the ultrafine particle generation chamber 31 It is sucked into the fine particle gas inlet 35 and transported to the film forming chamber 37. The above-described transport of the evaporated metal vapor into ultrafine particles from the ultrafine particle generation chamber 31 to the film formation chamber 37 is performed by being accompanied by the flow of the inert gas. Further, the formation of the metal film of the molding die base material 39 in the fine particle generation chamber 31 is performed by moving the molding die base material 39 in a direction indicated by an arrow b in FIG. Done. When depositing metals having different melting points, it is desirable that there are two ultrafine particle generation chambers.

As the mold base material used in this embodiment, it is desirable to use a WC cemented carbide in terms of hardness.

Further, in order to improve the adhesion between the cemented carbide base material and the cut layer formed by the gas deposition method, it is desirable to form an underlayer mainly composed of a metal by a sputtering method. It is desirable that the metal of the underlayer has the same composition as that of the cutting layer from the viewpoint of adhesion.

Then, a thin film of metal carbide, metal nitride, metal carbonitride or the like is formed as an intermediate layer on the cutting layer,
Thereafter, a release layer may be formed.

In this embodiment, the shape shortage between the desired shape and the shape of the forming base material that has been processed into an approximate shape is measured in advance, and the movement of the forming base material in the particle generation chamber is controlled with high precision. By forming a film while forming, the base material of the molding die can be formed into a desired shape. In this case, in order to obtain a mirror surface, it is desirable to perform uniform polishing without changing the shape.

Hereinafter, specific embodiments will be described.

Embodiment 1 In this embodiment, a cut layer made of metal was formed by a gas deposition apparatus as shown in FIG.

A rectangular parallelepiped (30 mm × 10 mm in the longitudinal direction, line-symmetrical) obtained by subjecting a WC-based cemented carbide sintered body to a predetermined free-form surface by electric discharge machining was used as a mold base material. After thoroughly cleaning the mold, it was set in a gas deposition apparatus.

Next, N was added to the water-cooled copper hearth in the ultrafine particle generation chamber.
The granules obtained by mixing i ₃ P and Cu at a weight ratio of 1: 1 were melted and evaporated by applying a DC voltage between the plasma torch and the water-cooled copper hearth. As a carrier gas, He, Ar,
It is conceivable to use a mixed gas of these, and a gas obtained by adding nitrogen thereto. In the case of manufacturing a film mainly composed of a high melting point material such as Ni ₃ P (melting point 965 ° C.) or Cu (melting point 1083 ° C.) formed in this embodiment, a carrier gas other than He easily forms an agglomerate and adheres. He is desirable because it causes a decrease in force. In this embodiment, the purity is 99.999.
9% He was used as a carrier gas. If the pressure in the ultrafine particle generation chamber at the time of film formation is 2 atm or more, agglomerates are easily formed and the adhesion to the substrate is reduced, so the pressure is preferably 2 atm or less. In this embodiment, it is 1 atm. The nozzle used had an inner diameter (10 mm × 0.1 mm). The distance between the nozzle and the mold base material was 3 mm. Further, in order to avoid generation of aggregates, a heating mechanism is provided in the nozzle and the transport pipe.

Thus, the ultrafine particle film sprayed through the gas transfer pipe was formed on the mold base material. The nozzle is fixed, and the stage holding the mold base material moves in x-y, z, and θ directions.

In this embodiment, this stage is operated in the longitudinal direction of the mold base material and in the direction in which the distance between the nozzle and the mold base material becomes 3 mm to form an alloy layer of Ni ₃ P and Cu of about 50 μm. It was also confirmed that there was no thickness unevenness and no wraparound to the side. The mold base material temperature at this time was 450 ° C. At this time, the use efficiency of the material was 98% or more.

Next, this processed layer is cut into a desired free-form surface by a diamond tool, and finished by uniform polishing.

Next, a TiN intermediate layer of 1 μm is formed on the processed layer by reactive sputtering using a Ti target and a nitrogen gas as an introduction gas.

Next, a surface layer of a hard carbon film having a thickness of 100 nm is formed on the intermediate layer by an ion beam evaporation method.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and no deterioration of the transfer surface was observed.

[Comparative Example 1] An optical element molding die was manufactured in the same manner as in Example 1, except that when forming a processed layer, sputtering was performed using a Ni ₃ P and Cu target. . When the glass moldability of this mold was measured, it was equal to that of Example 1. However, since a film having the same composition as the processing layer was formed on the side surface of the mold base material, additional processing by grinding was required to remove this portion. Further, due to the consumption of the target, the material utilization efficiency was 3% or less.

[Example 2] In Example 1, when forming a processed layer, instead of using Ni ₃ P and Cu granules,
One type selected from Ni ₃ P, Fe ₃ P (melting point 1100 ° C.), Co ₂ P (melting point 1386 ° C.) and Cu, Si (melting point 1
412 ° C), Ti (melting point 1668 ° C), Cr (melting point 18
An optical element molding die was manufactured in the same manner as in Example 1 except that a mixture with a weight of one of 75 ° C.) and Zr (melting point of 1850 ° C.) was used at a weight ratio of 1: 1. When the side wraparound state, the machinability, and the glass formability of this mold were measured, Example 1 was obtained.
Was equivalent to In addition, the usage efficiency of the materials was 98% or more.

FIG. 5 shows the types of target materials and the results.

Example 3 In Example 1, when forming a processed layer, instead of using Ni ₃ P and Cu granules,
One selected from Ni ₃ P, Fe ₃ P (melting point 1100 ° C.), Co ₂ P (melting point 1386 ° C.), and Nb (melting point 246)
8 ° C.), Mo (melting point 2615 ° C.), Hf (melting point 2222)
° C), Ta (melting point 2998 ° C), W (melting point 3380 ° C)
Of the two nozzles 48A and 48B so that the weight ratio becomes 1: 1 on the mold base material (see FIG. 4). An optical element molding die was manufactured in the same manner as in Example 1 except that the plasma arc power supply was controlled. When the side wraparound state, the machinability, and the glass formability of this mold were measured, Example 1 was obtained.
Was equivalent to In addition, the usage efficiency of the materials was 95% or more.

FIG. 6 shows the types of target materials and the results.

Example 4 Example 1 is the same as Example 1 except that a carbide, nitride or carbonitride of titanium, tantalum, chromium or silicon is formed instead of forming the intermediate TiN film. An optical element molding die was manufactured. The glass moldability of this mold was measured and found to be equivalent to that of Example 1.

FIG. 7 shows the types of intermediate layer materials and the results.

Example 5 In Example 1, Pt, Pd, Ir, and R were used instead of forming the hard carbon film of the surface layer.
An optical element molding die was manufactured in the same manner as in Example 1 except that a binary alloy of h, Os, Ru, Re, Au, W, and Ta was formed to 0.5 μm or more. The Vickers hardness and glass moldability of this mold were measured and found to be the same as in Example 1.

FIG. 8 shows the types of surface layer materials and the results.

In the embodiment of the present invention, the components are changed in the working layer, the intermediate layer and the surface layer. However, it is needless to say that the same effect can be obtained by combining these.

Example 6 A mold for molding an optical element was manufactured in the same manner as in Example 1, except that the intermediate layer was not formed.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 2,000 shot molding.
Deterioration of transfer accuracy was observed.

[Embodiment 7] In the embodiment 1, when forming the intermediate layer, the metal Ti is heated and evaporated by an electron gun, and the TiN is formed by ion plating in a nitrogen plasma.
A mold for molding an optical element was manufactured in the same manner as in Example 1 except for forming.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and no deterioration of the transfer surface was observed.

[Example 8] A WC-based cemented carbide sintered body was used as a mold base material (a minus tolerance from the desired free-form surface shape).
A rectangular parallelepiped (linearly symmetric in the longitudinal direction, 30 mm × 10 mm) which was subjected to electric discharge machining into a free-form surface shape was used.

The difference between this mold and a desired free-form surface shape is measured by a high-precision three-dimensional shape measuring instrument.

Next, the mold was thoroughly washed and then set in a gas deposition apparatus.

Then, a DC voltage was applied between the plasma torch and the water-cooled copper hearth with the granules obtained by mixing Ni ₃ P and Cu at a weight ratio of 1: 1 with the water-cooled copper hearth in the ultrafine particle generation chamber,
Melted and evaporated. In this embodiment, the purity is 99.9999%.
He was used as a carrier gas. The pressure in the ultrafine particle generation chamber during film formation was 1 atm. Nozzle inner diameter 0.00
A 2 mm one was used. The distance between the nozzle and the mold was 3 mm. Further, in order to avoid generation of aggregates, a heating mechanism is provided in the nozzle and the transport pipe.

The film was formed by controlling the xy, z, and θ axes on the stage. The mold temperature at this time was 450 ° C.

Next, this processed layer is subjected to finish processing by uniform polishing.

Next, on the processed layer, a TiN intermediate layer is formed to a thickness of 1 μm by reactive sputtering using a Ti target and a nitrogen gas as an introduction gas.

Next, a surface layer of a hard carbon film having a thickness of 100 nm is formed on the intermediate layer by an ion beam evaporation method.

When this mold was subjected to glass molding (phosphate glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and no deterioration of the transfer surface was observed.

In the method of manufacturing an optical element molding die having a cutting layer mainly composed of a metal formed on a base material according to the present embodiment, the metal is deposited at an arbitrary place by using a gas deposition method. A cutting layer having excellent machinability as a main component could be formed. This greatly contributed to the reduction in the number of processes, cost reduction, and resource saving. Also,
In particular, since the film formation range can be limited by conditions such as the nozzle shape and the distance between the nozzle and the mold base material, a cut layer is formed only on a desired surface of the mold base material, and the wraparound to the side surface is prevented. It became possible.

In addition, the lack of the shape of the molding die base material processed into the desired shape and the approximate shape is measured in advance, and only the lack of the shape is formed by the gas deposition method, so that the cutting which has not been achieved before can be achieved. It has become possible to manufacture optical element molding dies without processing.

[0084]

As described above, according to the present invention, an optical element having a free-form surface, which cannot be realized by conventional grinding, can be formed irrespective of molding conditions and glass type.
Provided is a method for efficiently manufacturing a mold capable of transferring a shape precisely even when press molding is repeatedly performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an optical element molding die according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of an optical element molding die according to a modification of the embodiment of the present invention.

FIG. 3 is a schematic view of a gas deposition film forming apparatus according to one embodiment.

FIG. 4 is a schematic cross-sectional view of the vicinity of a nozzle in a film forming chamber according to a third embodiment.

FIG. 5 is a diagram showing types of target materials and their results.

FIG. 6 is a diagram showing types of target materials and their results.

FIG. 7 is a diagram showing types of intermediate layer materials and their results.

FIG. 8 is a diagram showing types of surface layer materials and their results.

[Explanation of symbols]

 11, 21, 39, 49 Mold base material 12, 22 Cutting layer 13, 24 Surface layer 23 Intermediate layer 31 Ultrafine particle generation chamber 32 Power supply for plasma arc 33 Plasma torch 34 Water-cooled copper hearth 35 Ultrafine particle gas inlet 36 Transport pipe 37 Film formation chamber 38, 48A, 48B Nozzle

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 3/02 G02B 3/02 // B29L 11:00 B29L 11:00 (72) Inventor Nao Miyazaki Tokyo 3-30-2 Shimomaruko, Ota-ku Canon Inc. F-term (reference) 4F202 AJ02 AJ09 AJ11 CA30 CB01 CD18 CD22 CD30 CK11 4G015 HA01 4K029 AA04 BA22 BA24 BA25 BA26 BA34 BB02 BD05 CA03 CA05 GA03

Claims (16)

[Claims] An optical element molding die having a transfer surface for molding an optical element on a part of a base material, wherein a cutting layer mainly composed of metal is gas-deposited on the base material. A mold for forming an optical element, characterized by being formed by a method. 2. The method according to claim 1, wherein the base material is tungsten carbide (W).
C) as a main component, and the cutting layer is made of nickel (Ni), cobalt (Co), iron (Fe).
Alloy of phosphorus (P) and copper (C)
u), silicon (Si), titanium (Ti), chromium (C
r), zirconium (Zr), niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (T
2. The optical element molding die according to claim 1, comprising a ternary alloy of a) and one type selected from tungsten (W). 3. The method according to claim 1, wherein a base layer mainly composed of a metal is formed on the base material by a sputtering method, and then the cut layer mainly composed of a metal is formed by a gas deposition method. The mold for molding an optical element according to claim 1. 4. The method according to claim 1, wherein the base material is tungsten carbide (W).
C) as a main component, and the underlayer and the cutting layer are made of nickel (Ni), cobalt (C
o), one type selected from iron (Fe) and phosphorus (P)
Alloy with copper (Cu), silicon (Si), titanium (T
i), chromium (Cr), zirconium (Zr), niobium (Nb), molybdenum (Mo), hafnium (Hf),
1 selected from tantalum (Ta) and tungsten (W)
4. The mold for molding an optical element according to claim 3, wherein the mold comprises a ternary alloy. 5. The optical element molding die according to claim 1, wherein the transfer surface is a free-form surface. 6. The optical element molding die according to claim 1, wherein the thickness of the cut layer is 50 μm or more. 7. A method for producing an optical element molding die having a transfer surface for molding an optical element on a part of a base material, comprising: a cutting layer mainly composed of metal on the base material. Is formed by a gas deposition method. 8. A method according to claim 8, wherein a base layer mainly composed of a metal is formed on the base material by a sputtering method, and then the cutting layer mainly composed of a metal is formed by a gas deposition method. The method for manufacturing an optical element molding die according to claim 7. 9. Nickel (Ni), cobalt (Co),
A chamber for generating ultrafine particles of an alloy of one selected from iron (Fe) and phosphorus (P), and niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (Ta) and tungsten (W) The method for manufacturing an optical element molding die according to claim 7, wherein the cut layer is formed by a gas deposition method using a selected one type of ultrafine particle generation chamber separately. 10. A method for producing an optical element molding die having a transfer surface for molding an optical element on a part of a base material, comprising: a cutting layer mainly composed of metal on the base material. After the film is formed by a gas deposition method, after the cutting layer is cut into a desired shape and uniformly polished, on the processing layer, in the case of a hard carbon film, ion beam evaporation, in the case of a noble metal alloy thin film, Is a method for producing an optical element molding die, wherein a surface layer is formed by sputtering. 11. The method for manufacturing an optical element molding die according to claim 10, wherein an underlayer mainly composed of a metal is formed between the base material and the cut layer by sputtering. . 12. Between the cutting layer and the surface layer,
The method for manufacturing an optical element molding die according to claim 10, wherein an intermediate layer made of a metal carbide, nitride, or carbonitride is formed. 13. A method of manufacturing an optical element molding die having a transfer surface for molding an optical element on a part of a base material, wherein the base material has a shape approximate to a minus tolerance of a desired shape. Processing, and, depending on the difference between the approximate shape and the desired shape of the base material, a step of forming a shape-forming layer containing a metal as a main component with high precision by a gas deposition method, An optical element, comprising: a step of performing uniform polishing; and a step of forming a surface layer on the shape forming layer by ion beam evaporation for a hard carbon film or sputtering for a noble metal based alloy thin film. A method for manufacturing a molding die. 14. The optical element molding according to claim 13, further comprising a step of forming a base layer mainly composed of a metal between the base material and the shape forming layer by a sputtering method. Manufacturing method of mold. 15. The base material is made of a cemented carbide mainly containing tungsten carbide (WC), and the underlayer and the shape forming layer are made of nickel (Ni), cobalt (Co), iron (Fe). An alloy of one selected from the group consisting of phosphorus (P), copper (Cu), silicon (Si), titanium (Ti), chromium (Cr), zirconium (Zr),
Niobium (Nb), molybdenum (Mo), hafnium (H
The method of manufacturing an optical element molding die according to claim 14, comprising a ternary alloy of one type selected from f), tantalum (Ta), and tungsten (W). 16. The method according to claim 16, further comprising the step of:
14. The method for manufacturing an optical element molding die according to claim 13, further comprising a step of forming an intermediate layer made of a metal carbide, nitride, or carbonitride.