JP3064637B2 - Infrared lens manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical lens, particularly an infrared transmitting lens using a silver halide crystal.

[0002]

2. Description of the Related Art In recent years, as a method for mass-producing optical lenses, a press molding method, which has the advantages of greatly simplifying the process and easily processing a high-performance aspherical lens, has attracted attention.

[0003] Silver halide crystals are expected to be used as materials for high-sensitivity lenses for infrared sensors, taking advantage of their high transmittance, but have the problem that polishing is difficult and not suitable for mass production.

[0004] On the other hand, silver halide crystals have high plastic deformability so that they can be formed into fibers by extrusion, and take advantage of such features that other materials do not have. Expectations for mass production of lenses are increasing.

Hereinafter, an example of a conventional manufacturing method will be described with reference to the drawings. FIG. 6 shows a cross-sectional structure of a main part of an apparatus used in a conventional infrared lens manufacturing method. Reference numeral 21 denotes an upper lens mold having a mirror surface portion 22 for transferring a lens shape, and reference numeral 23 denotes a lens. This is a lower lens mold having a mirror surface portion 24 for transferring a shape. Reference numeral 25 denotes a lens glass material made of silver halide crystals such as silver chloride and silver bromide, which is cut out to an appropriate size.
(JP-A-59-212801).

The operation will be described below. When the lens glass material 25 is placed at the center between the upper and lower lens molds 21 and 23 and pressurized from above, the lens glass material 25 is
Flows along to transfer the lens shape.

[0007]

However, in the above-described structure, as shown in FIG. 7, the flow of the material at the center of the mirror surface of the lens glass material cut out hardly occurs. There is a problem that grinding flaws remain after molding.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a method of manufacturing an infrared lens for transferring a desired lens shape without leaving a surface flaw on a lens glass material.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a mold comprising a mirror portion for transferring a lens shape and an edge portion surrounding the mirror portion, and accommodating the mold.
A container, a pressure rod, and a diameter larger than a diameter of the mirror surface portion.
Using a disk-shaped lens glass material smaller than the diameter of the mold, the mirror surface
Part and the lens glass material are decentered, and the lens glass material is
The entire periphery of the flat part is in contact with the edge, and inside the container.
The present invention is characterized in that a desired lens shape is obtained by pressing while holding the lens glass material so as to have a gap between the wall and the wall . Further, the present invention uses a mold comprising a mirror surface portion for transferring a lens shape and an edge portion surrounding the mirror surface, a container for accommodating the mold, a pressure rod, and
It is larger than the diameter of the mirror surface and smaller than the diameter of the mold.
Using a parallel wedge-shaped disc lens glass material,
The lens is provided with a characteristic that a desired lens shape is obtained by pressing while holding the lens glass material at the concentric position of the mirror surface portion .

[0010]

According to the present invention, when the lens glass material eccentrically held by the mold is pressed by the pressing rod, micro plastic deformation is caused from the outer periphery of the flat portion of the lens glass material along the mirror surface of the mold. proceed. In other words, the lens glass material installed eccentrically flows along the mirror surface of the mold, and the entire lens surface becomes a flowing surface and becomes a mirror surface because the lens shape is gradually transferred. The remaining scar disappears.

Further, by pressing the wedge-shaped lens glass material, the lens material flows from the thick portion along the mirror surface of the mold, and the lens shape is gradually transferred, so that the entire lens surface becomes a flowing surface and becomes a mirror surface. Therefore, the scratches remaining on the surface of the lens material disappear.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method for manufacturing an infrared lens according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of an infrared lens manufacturing apparatus which embodies an infrared lens manufacturing method according to one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an upper lens mold,
A mirror portion 2 for transferring a lens shape, and a lens glass material 8
And has an edge portion 3 for holding and pressing. Reference numeral 4 denotes a lower lens mold, which is a mirror surface portion 5 for transferring a lens shape.
And an edge portion 3 for holding and pressing the lens glass material 8. Reference numeral 6 denotes a container in which the upper and lower dies 1, 4 and the pressure rod 7 are slidably housed. 8 is a lens glass material consisting of silver halide crystals such as silver chloride, silver bromide, example
For example, smaller than the diameter of the molds 1 and 4, and the mirror surface portion 2,
Than the diameter of 5 that have been cut into large disc-shaped.

The operation of the infrared lens manufacturing apparatus configured as described above will be described with reference to FIGS.

First, as shown in FIG. 1, the lower lens mold 4 is inserted into the container 6 with the mirror part 5 facing upward, and then the lens glass material 8 is placed on the mirror part 5 of the lower lens mold 4.
And the entire circumference of the plane portion of the lens glass material 8 is
A gap between the container 3 and the inner wall of the container 6
The lens glass material 8 is placed so as to have the following. Next, when inserting the upper lens molds 1 and the mirror unit 2 downwards, the <br/> lens glass material 8 is polarized between the edge portion 3 of the upper and lower lens mold 1,4
It is in a state of being held in mind .

Next, the pressure rod 7 is inserted, and in this state, the pressure rod 7 is
When pressure is applied to the lens , the lens glass material 8 undergoes plastic deformation.
Then, as shown in FIG. 2, an infrared lens having a transferred lens shape can be obtained.

When pressure is applied to the pressure rod 7, as shown in FIG.
As described above, the lens glass material 8 is first used for the upper and lower lens molds 1 and 4.
The edge 3 is pressed by the edge 3 in contact with the
Part flows to the inner wall side of the container 6, and the non-contact part gradually moves up and down.
Flow along the mirror surfaces 2 and 5 and the edge 3 of the lens molds 1 and 4
And some reach the inner wall of the container first,
Due to continuous pressing, the gap does not flow to the inner wall
The lens shape gradually transfers to the side with
It is something to be done.

As described above, according to this embodiment, the lens glass material is decentered with respect to the lens mold, thereby gradually
The lens shape was transferred and the entire lens surface flowed
The material flows even in the central part of the mirror surface because it becomes a mirror surface.
That eliminates scratches remaining on the lens glass surface
It is.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a sectional view of a main part of a manufacturing apparatus embodying a second embodiment of the manufacturing method of the present invention, and has the same configuration as that of FIG. In FIG. 4, reference numeral 1 denotes an upper lens mold, which has a mirror surface portion 2 for transferring a lens shape and an edge portion 3 for pressing. 4 is a lower lens mold,
It has a mirror surface portion 5 for transferring the lens shape and an edge portion 3 for pressing. Reference numeral 6 denotes a container in which the upper and lower dies 1, 4 and the pressure rod 7 are slidably housed. 11 for example, a lens glass material consisting of silver halide crystals such as silver-silver bromide chloride, larger than the diameter of the mirror surface portion 2, 5 the gold
Formed into a wedge-shaped disk with smaller diameters than molds 1 and 4 and non-parallel on both sides
Is done.

The operation of the infrared lens manufacturing method having the above-described structure will be described with reference to FIGS.

[0022] First, the container 6, as shown in FIG. 4, by inserting the lower lens mold 4 by the mirror surface portion 5 upwards, then a wedge-shaped disc lens glass material 11 of the lower lens mold 4 center sand
That is, it is placed at the concentric position of the mirror surface portion 5 . Next, when the upper lens mold 1 is inserted with the mirror surface portion 2 facing downward, the wedge
The thick part of the glass lens 11 is made of the upper and lower lens molds 1, 4
Between the edges 3 and the thin portion is in a non-contact state.
You.

Next, the pressure rod 7 is inserted, and in this state, the pressure rod 7
When pressure is applied to the lens , the lens glass material 11 undergoes plastic deformation.
As shown in FIG. 2, an infrared lens having a transferred lens shape can be obtained.

When pressure is applied to the pressure rod 7, as shown in FIG.
As described above, first, the thick portion of the lens glass material 11 has upper and lower lens gold.
Pressed by the edge portions 3 of the molds 1 and 4 which are in contact, the edge portions 3
A part of flows along the inner wall side of the container 6 along the
The mirror surfaces 2, 5 of the upper and lower lens molds 1, 4 and the edge 3 gradually
Flows along and partially reaches the inner wall of the container first
Then, as the pressing continues, the inner wall
Since it flows to the side with a gap without flowing, the lens gradually
The shape is transferred.

As described above, according to this embodiment, the lens glass
By making the material a wedge-shaped disk, the lens shape gradually rolls.
It is mirrored as the whole lens surface becomes a flowing surface
There is a flow of material even in the center of the mirror surface,
The scratches remaining on the surface of the glass material disappear.

[0026]

As described above, according to the method for manufacturing an infrared lens of the present invention, the disk-shaped lens material eccentrically installed flows along the mirror surface of the mold, and the lens shape is gradually transferred. Because the entire lens surface becomes a flowing surface and becomes a mirror surface, scratches remaining on the lens glass material surface are eliminated, a mirror surface lens surface with excellent transferability is obtained, and mass production of highly accurate aspheric lenses It becomes possible.

Further, by pressing the lens glass material of the wedge-shaped disk , the lens material flows from the thick part along the mirror surface of the mold, and the lens shape is gradually transferred, so that the entire lens surface becomes a flowing surface. Since the surface of the lens is made mirror-finished, scratches remaining on the surface of the lens glass material are eliminated, a mirror surface of the lens having excellent transferability is obtained, and mass production of highly accurate aspherical lenses becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an infrared lens manufacturing apparatus that embodies a first embodiment method of the present invention.

FIG. 2 is a view showing a molding state of an infrared lens by the manufacturing apparatus.

FIG. 3 is a diagram illustrating the operation of the manufacturing apparatus.

FIG. 4 is a sectional view of an infrared lens manufacturing apparatus embodying the method of the second embodiment of the present invention.

FIG. 5 is an explanatory diagram of an operation in the embodiment.

FIG. 6 is a sectional view of a main part of a conventional infrared lens manufacturing apparatus.

FIG. 7 is a diagram illustrating the operation of the conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper lens mold 2 Mirror part 3 Edge part 4 Lower lens mold 5 Mirror part 8 Lens glass material

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Claims (2)

(57) [Claims] 1. A mold comprising a mirror surface portion for transferring a lens shape and an edge portion surrounding the mirror surface portion, and storing the mold portion .
Container, a pressure rod, and a front portion larger than the diameter of the mirror surface portion.
Using a disk-shaped lens glass material smaller than the diameter of the
Decentering the surface and the lens glass material, and the lens glass material
The entire periphery of the flat portion of the container contacts the edge portion, and the container
A method of manufacturing an infrared lens, wherein a desired lens shape is obtained by pressing while holding the lens glass material so as to have a gap with an inner wall . Used wherein the mirror unit for transferring the lens shape and the mold comprising a flange portion surrounding it, yield the mold
Container to be packed, pressurizing rod, and larger than the diameter of the mirror surface
A wedge-shaped disk len which is smaller than the diameter of the mold and whose both sides are non-parallel
Using the lens glass material, the lens glass material is
A method of manufacturing an infrared lens, wherein a desired lens shape is obtained by pressing while holding at a concentric position of a portion .