JP2003071855A - Optical element processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical element having good shape accuracy or surface roughness by suppressing the deformation of an optical material or the generation of a chatter mark in the optical material at processing. SOLUTION: In the optical element processing method for obtaining the optical element by processing the optical material 1 by cutting or grinding, the space between the holding member 3 for holding the optical material 1 and the optical material 1 is filled with a curable liquid material 5 and, thereafter, the curable liquid material 5 is cured. In such a state, the optical material 1 is processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing an optical element, such as a lens or a prism, which is made of a material such as plastic that is easily deformed, by cutting or grinding.

[0002]

2. Description of the Related Art First, FIG.
A conventional processing method (prior art 1) for manufacturing the plastic lens shown in FIG. 3 will be described. 1 is a perspective view of an optical material of a plastic lens, FIG. 2 is a longitudinal sectional view of the optical material of the plastic lens, and FIG. 3 is a side view of the plastic lens. When the plastic lens 1A as a thin concave meniscus optical element shown in FIG. 3 is cut, as shown in FIGS. 1 and 2, the mounting portion 1a is provided on the outer periphery.
A lens blank 1 as an optical material having a near net shape is manufactured. Next, as shown in FIG. 2, a holder of a precision processing machine (not shown) holds the mounting portion 1a of the lens blank 1, and the optical surface A and the optical surface B are cut. Then, the mounting portion 1a of the lens blank 1 is cut off to obtain the plastic lens 1A shown in FIG.

A conventional processing method (prior art 2) for processing the plastic prism as the optical element shown in FIG. 4 used in the second to fourth embodiments will be described later.
FIG. 4 is a perspective view of the optical material of the plastic prism. As shown in FIG. 4, the prism blank 2 as an optical material uses an NC machine tool in a near-net shape in which two mounting portions 2b are provided on the side surface portion 2d (including the facing surface) that is not an optical surface. Produced. Next, a holder of a precision processing machine (not shown) holds the mounting portion 2b of the prism blank 2 and sequentially processes each optical surface C, D, E of the plastic prism.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 6-226610 (conventional technique 3), the lens material, which is an optical material, is attached to the lens holding member for processing, but the back surface of the processed surface is also optically processed. Since it is a surface, the lens holding member has a hollow central portion so as to avoid the optical surface of the lens material.

[0005]

However, the above-mentioned prior art has the following problems. That is, in the prior art 1, when the thickness of the plastic lens is thin, the lens blank 1 as the workpiece is deformed by the cutting of the tool in the step of processing the optical surface after the blank processing,
There is a problem that a desired shape cannot be obtained.
If the unprocessed back surface is pressed from the back so that it does not deform during processing, it will not deform, but if it is necessary to press the processed optical surface, it is necessary to press it with a mold with the inverted optical surface. Yes, in this case, it was expensive and expensive to manufacture the inverted mold. Also,
Since the optical surface has been precision processed and there is nothing to fix the lens 1A when the mounting portion 1a and the lens 1A are separated,
The position of the lens 1A shifts as the outer periphery is separated,
The outer circumference could not be separated accurately.

[0006] In the prior art 2, in the thick portion of the plastic prism, the deformation due to the cutting of the tool is small, but in the peripheral portion, the thickness is thin, so that the deformation or chattering occurs and the desired shape and surface roughness are obtained. There was a problem that I could not.

In the prior art 3, since there is no support at the center of the lens holding member, when processing a lens that is thin in the center, the lens that is the object to be processed is deformed to obtain the desired shape. There was a problem that I could not do it.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the invention according to claim 1, 2, 3 or 4 is to prevent deformation and chattering of an optical material during processing, and to improve the shape accuracy. Another object of the present invention is to provide an optical element processing method capable of obtaining an optical element having good surface roughness.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1, 2, 3 or 4 is a method of processing an optical element for processing an optical material by cutting or grinding to obtain an optical element. In (1), after filling the space between the optical material and a holding member that holds the optical material with a curable liquid material, the curable liquid material is cured, and the optical material is processed in that state.

In the method for processing an optical element of the invention according to claim 1, 2, 3 or 4, after filling the curable liquid material in the space between the holding member holding the optical material and the optical material,
By curing the curable liquid material and processing the optical material in that state, the cured curable liquid material integrates the optical material and the holding member, and receives the processing force of the optical material,
Backs up the thin part of the optical material.

In the method for processing an optical element according to a second aspect of the present invention, in addition to the above-mentioned effects, the curable liquid material is a thermoplastic material, and thus the curable liquid material is melted or solidified by heating and cooling.

In the method for processing an optical element according to the third aspect of the present invention, in addition to the above action, the curable liquid material is a reaction-curable elastic material, so that the curable liquid material is cured by chemical treatment. Or soften.

In the method of processing an optical element according to a fourth aspect of the present invention, in addition to the above-mentioned effects, before the space between the holding member for holding the optical material and the optical material is filled with the curable liquid material, the optical material is previously optically By forming the coating of the reaction-curable elastic material on the element, the coating of the reaction-curable elastic material prevents the curable liquid material from eroding the optical surface of the optical element.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Specific embodiments will be described below.

(Embodiment 1) FIGS. 1 to 3 and 5
10 shows the first embodiment, FIGS. 1 to 3 have already been described in the prior art, and FIG. 5 is a longitudinal sectional view of a processing jig with a lens blank attached for processing the optical surface A. 6 is an explanatory view of a state where the processing jig is filled with wax, and FIG.
Is an explanatory view of the state where the wax is solidified, FIG. 8 is a vertical cross-sectional view of the processing jig with a lens blank attached for processing the optical surface B, and FIG. 9 is an explanation of the state where the processing jig is filled with wax again. FIG. 10 and FIG. 10 are explanatory views of the state where the wax is solidified again.

First, as already described with reference to FIGS. 1 to 3, the lens blank 1 as an optical material has a near net shape having a mounting portion 1a on the outer periphery, and finally has a thin shape shown in FIG. It is processed into a plastic lens 1A as a concave meniscus optical element. The material of the lens blank 1 is polycarbonate or PMMA.

Next, a processing method for obtaining the plastic lens 1A from the lens blank 1 will be described. In FIG. 5, the processing jig includes a lens holder 3 as a holding member that holds the outer periphery of the lens blank 1 and the lens blank 1.
The lens blank holder 4 for suppressing the thrust direction of the lens blank 3 is fitted in the lens holder holder 3 so that the mounting portion 1a of the lens blank 1 is fitted to the lens portion 3a of the lens holder 3 so that the optical surface A can be processed. Next, as shown in FIG. 6, the processing jig is set vertically so that the hollow portion 3b of the lens holder 3 faces upward. A space formed by the unprocessed optical surface B of the lens blank 1 and the hollow portion 3b of the lens holder 3 is filled with a melted wax 5 as a curable liquid material and a thermoplastic material. After the wax 5 is hardened and solidified, as shown in FIG. 7, a processing jig in which the wax 5 is filled and solidified is attached to a precision processing machine (not shown) to finish the optical surface A.

After finishing the optical surface A, the processing jig is removed from the precision processing machine, and the lens blank 1 having the optical surface A finished is warmed and the wax 5 in the lens holder 3 is removed. Next, as shown in FIG. 8, the lens blank 1 is turned over so that the optical surface B can be processed, and is fixed by the lens blank retainer 4. Then, FIG.
As shown in, in the space on the finished optical surface A side,
The molten wax 5 is filled. After the wax 5 is solidified, as shown in FIG. 10, a processing jig in which the wax 5 is filled and solidified is attached to a precision processing machine (not shown) to finish the optical surface B of the lens blank 1. After finishing the optical surface B, from the lens holder 3 to the lens blank holder 4
Is removed, and the solidified wax 5 and the lens blank 1 are adhered to each other and removed in a state of being integrated.
Next, the machine tool (not shown) is caused to grip the outer periphery of the solidified wax 5, the mounting portion 1a of the lens blank 1 is cut off, and the outer periphery of the plastic lens 1A is accurately processed. Finally, the solidified wax 5 and the plastic lens 1A are warmed to melt the wax 5, and the plastic lens 1A is separated.

According to the present embodiment, since the back surface is supported by the solidified wax when the optical surface of the plastic lens is subjected to precision finishing, the processing surface of the plastic lens is bent by the processing force such as cutting force. There is no such thing. Therefore, it is possible to suppress the occurrence of chattering and deformation and obtain a plastic lens having good shape accuracy and surface roughness. Also,
When the processed surface is turned over and supported, the melted wax receives the optical surface in an inverted shape, so the processed surface does not get scratched and there is no need to make a mold, so it can be cheaper. . Further, when the plastic lens is separated from the mounting portion after the precision finishing of both surfaces is completed, the plastic lens is stuck to the solidified wax, so that the outer periphery can be processed with high precision.

In the present embodiment, the plastic lens has been described as an example, but the present invention can be applied to the grinding and polishing process of a glass lens having a similar shape, with a slight modification.

(Second Embodiment) FIG. 4 and FIGS. 11 to 1
7 shows the second embodiment, FIG. 4 has already been described in the prior art, and FIG. 11 is a perspective perspective view of a processing jig with a prism blank attached to process the optical surface C.
2 is a vertical cross-sectional view of FIG. 11, FIG. 13 is an explanatory view of a state in which a space between the processing jig and the prism blank is filled with wax, and FIG. 14 is a state in which a prism blank is attached for processing the optical surface D. FIG. 15 is a vertical cross-sectional view of the processing jig, FIG. 15 is an explanatory view of a state in which the space between the processing jig and the prism blank is filled with wax, and FIG. 16 is a processing in which the prism blank is attached for processing the optical surface E. FIG. 17 is a vertical cross-sectional view of the jig, and FIG. 17 is an explanatory view of a state in which the space between the processing jig and the prism blank is filled with wax.

First, as already described with reference to FIG.
The prism blank 2 as an optical material has an optical surface A,
It is an optical material of a plastic prism as an optical element having B and C, and a mounting portion 2b is projected at two places on a side surface portion 2d which is not an optical surface. The material of the prism blank 2 is polycarbonate or PMMA.

Next, a processing method for obtaining a plastic prism from the prism blank 2 will be described. Figure 11
In the processing jig 6 as a holding member, a hollow portion 6 a for housing the prism blank 2 in a rectangular parallelepiped block.
And two supporting portions 6b for holding the mounting portion 2b of the prism blank 2. The support portion 6b is arranged at a position such that when the mounting portion 2b of the prism blank 2 is mounted, the optical surface C of the prism blank 2 which is the surface to be processed protrudes from the upper surface of the processing jig 6 and can be processed. The same applies to the processing jig 6A shown in FIGS. 14 and 15 and the processing jig 6B shown in FIGS. 16 and 17, which will be described later.

First, as shown in FIG. 12, the processing jig 6
Then, the prism blank 2 is mounted so that the optical surface C faces upward. Next, as shown in FIG. 13, the molten wax 5 is placed in the space between the processing jig 6 and the prism blank 2.
And then solidify. This is attached to a precision processing machine (not shown) to finish the optical surface C. After the processing is finished, the processing jig 6 is removed from the precision processing machine, warmed to remove the wax 5, and the optical surface C is removed from the processing jig 6. The prism blank 2 processed by is removed.

Next, as shown in FIG.
The prism blank 2 is attached to A so that the optical surface D faces upward. Next, as shown in FIG. 15, the processing jig 6A
The molten wax 5 is filled into the space between the prism blank 2 and the prism blank 2 and solidified. Further, the optical surface D is finished in the same manner as the optical surface C. The optical surface E is also shown in FIG.
6 and FIG. 17, using the processing jig 6B,
Finish as in the case of the optical surfaces C and D.

According to the present embodiment, since the space between the processing jig and the prism blank is filled with wax, the filled wax functions as a strength member even in the thin portion of the plastic prism. As a substitute, it is possible to obtain a plastic prism having good shape accuracy and surface roughness while suppressing chattering and deformation of the plastic prism during processing.

In the present embodiment, the plastic prism has been described as an example, but the present invention can also be applied to the grinding and polishing process of a glass prism having a similar shape with a slight modification.

(Third Embodiment) The present embodiment shows a modification of the second embodiment, which is different from the second embodiment only in the optical material and the curable liquid material, and the other portions are the same. Therefore, only different parts will be described, and drawings and description of similar parts will be made with reference to FIGS. 12 to 17 of the second embodiment.

In the present embodiment, as the optical material, polyolefin is used instead of the material of the prism blank 2 of the second embodiment to polycarbonate or PMMA. As the curable liquid material, instead of the wax 5, silicone 7 as a reaction-curable elastic material is used. The other structure of the processing jig and the processing sequence of the prism blank 2 are the same as those in the second embodiment.

Next, a processing method for obtaining a plastic prism from the prism blank 2 will be described. First,
As shown in FIG. 12, the prism blank 2 is mounted on the processing jig 6 so that the optical surface C faces upward. Next, FIG.
As shown in FIG. 3, the space between the processing jig 6 and the prism blank 2 is filled with the softened silicone 7 and cured. This is attached to a precision processing machine (not shown) and the optical surface C is attached.
Finish processing. After the processing is completed, the processing jig 6 is removed from the precision processing machine, and the prism blank 2 having the optical surface C processed and the silicone 7 attached to the other surface is removed from the processing jig 6. Then, the silicone 7 is softened and removed from the prism blank 2.

Next, as shown in FIG. 14, the processing jig 6
The prism blank 2 is attached to A so that the optical surface D faces upward. Next, as shown in FIG. 15, the processing jig 6A
The molten silicone 7 is filled in the space between the prism blank 2 and the prism blank 2 and solidified. Further, the optical surface D is finished in the same manner as the optical surface C. Also, the optical surface E is
As shown in FIGS. 16 and 17, the processing jig 6B is used to finish the optical surface C and the optical surface D in the same manner.

According to the present embodiment, in addition to the effect similar to that of the second embodiment, when the optical surface of the prism blank is easily corroded by a wax component or the like, by using silicone, the optical surface of the prism blank is improved. It is possible to prevent erosion.

(Embodiment 4) FIGS. 18 and 19 show Embodiment 4, and FIG. 18 is a vertical sectional view of a processing jig in which a prism blank having a silicone coating adhered to an unprocessed surface is attached, FIG. 19 is an explanatory diagram showing a state in which the space between the processing jig and the prism blank is filled with wax.
The present embodiment shows another modified example of the second embodiment, which is different from the second embodiment only in the optical material and the curable liquid material, and the other portions are the same, so only different portions will be described. The same parts as in FIG. 12 are described with reference to FIG.
~ Perform with reference to FIG.

In this embodiment, as the optical material, polyolefin is used instead of the material of the prism blank 2 of Embodiment 2 to polycarbonate or PMMA. Also, the curable liquid material uses wax 5,
Before that, the prism blank 2 is once dipped in silicone 7 to form a coating. Other structures of the processing jig and the processing sequence of the prism blank 2 are almost the same as those in the second embodiment.

Next, a processing method for obtaining a plastic prism from the prism blank 2 will be described. First,
As shown in FIG. 12, the prism blank 2 is mounted on the processing jig 6 so that the optical surface C faces upward. Next, FIG.
As shown in 3, the space between the processing jig 6 and the prism blank 2 is filled with the melted silicone 7, the silicone 7 is adhered to the optical surfaces D and E, and then the silicone 7 is discharged. Thereby, as shown in FIG. 18, a thin coating of silicone 7 is formed on the optical surfaces D and E. In this state, the silicone 7 coating is cured. Next, as shown in FIG. 19, the wax 5 melted in the space 6a between the processing jig 6 and the prism blank 2 is used.
And then solidify. This is attached to a precision processing machine (not shown) to finish the optical surface C. After the processing is completed, the processing jig 6 is removed from the precision processing machine, and the optical blank C is processed from the processing jig 6, and the prism blank 2 having the wax 5 attached to the other surface is removed. Then, the wax 5 is warmed to remove the wax 5 from the prism blank 2. Further, the silicone blank 7 is softened and removed from the prism blank 2.

Next, as shown in FIG. 14, the processing jig 6
The prism blank 2 is attached to A so that the optical surface D faces upward. Further, as shown in FIG.
The molten silicone 7 is filled in the space between the prism blank 2 and the prism blank 2 and the optical surface C and the optical surface E are filled with the silicone 7.
After depositing the silicone, the silicone 7 is discharged. As a result, a thin film of silicone 7 is formed on the optical surfaces C and E. In this state, the silicone 7 coating is solidified. Further, the optical surface D is finished in the same manner as the optical surface C. The optical surface E is also shown in FIGS.
As shown in FIG. 5, the processing jig 6B is used to finish the optical surfaces C and D in the same manner.

According to the present embodiment, in addition to the effect similar to that of the third embodiment, when the plastic prism with silicone is removed from the processing jig or when the silicone is removed from the plastic prism, the plastic prism is not easily removed. Since no force is applied, the prism is not deformed.

[0038]

According to the invention of claim 1, 2, 3 or 4, the hardened curable liquid material integrates the optical material and the holding member, receives the processing force of the optical material, and receives the optical material. Since the thin-walled portion is backed up, chattering and deformation of the optical material during processing can be suppressed, and an optical element with good shape accuracy and surface roughness can be obtained.

According to the invention of claim 2, in addition to the above effect, the curable liquid material is melted or solidified by heating and cooling, so that the working jig and the optical material can be easily integrated and separated. Can be done.

According to the invention of claim 3, in addition to the above effect, the curable liquid material is hardened or softened by a chemical treatment. Therefore, the working jig and the optical material are integrated and separated. Can be done easily and
It is possible to protect the optical surface of the optical material from erosion.

According to the invention of claim 4, in addition to the above effect, the coating made of the reaction-curable elastic material prevents the optical surface of the optical element from being corroded by the curable liquid material, so that the optical material can be easily handled. Becomes

[Brief description of drawings]

FIG. 1 is a perspective view of an optical material of a plastic lens according to a related art 1 and a first embodiment.

FIG. 2 is a longitudinal sectional view of an optical material of a plastic lens according to the related art 1 and the first embodiment.

FIG. 3 is a side view of a plastic lens according to the related art 1 and the first embodiment.

FIG. 4 is a perspective view of an optical material of a plastic prism according to the related art 2 and the second embodiment.

FIG. 5 is a vertical cross-sectional view of a processing jig with a lens blank attached for processing the optical surface A according to the first embodiment.

FIG. 6 is an explanatory diagram showing a state in which the processing jig of the first embodiment is filled with wax.

FIG. 7 is an explanatory view of a solidified wax according to the first embodiment.

FIG. 8 is a vertical cross-sectional view of a processing jig with a lens blank attached for processing the optical surface B according to the first embodiment.

FIG. 9 is an explanatory diagram showing a state where the processing jig of the first embodiment is filled with wax again.

FIG. 10 is an explanatory diagram showing a state in which the wax of the first embodiment has been solidified again.

FIG. 11 is a perspective perspective view of a processing jig with a prism blank attached for processing the optical surface C according to the second embodiment.

FIG. 12 is a vertical sectional view of FIG. 11 according to the second embodiment.

FIG. 13 is an explanatory diagram showing a state where wax is filled in a space between the processing jig and the prism blank according to the second embodiment.

FIG. 14 is a vertical cross-sectional view of a processing jig with a prism blank attached for processing the optical surface D according to the second embodiment.

FIG. 15 is an explanatory diagram showing a state where wax is filled in the space between the processing jig and the prism blank according to the second embodiment.

FIG. 16 is a vertical cross-sectional view of a processing jig with a prism blank attached for processing the optical surface E according to the second embodiment.

FIG. 17 is an explanatory diagram showing a state where wax is filled in the space between the processing jig and the prism blank according to the second embodiment.

FIG. 18 is a vertical cross-sectional view of a processing jig in a state where a prism blank having a silicone coating adhered to the unprocessed surface of Embodiment 4 is attached.

FIG. 19 is an explanatory diagram showing a state where wax is filled in the space between the processing jig and the prism blank of the fourth embodiment.

[Explanation of symbols]

1 lens blank 3 lens holder 5 wax

Claims (4)

[Claims] 1. A method of processing an optical element for processing an optical material by cutting or grinding to obtain an optical element, comprising filling a curable liquid material in a space between a holding member holding the optical material and the optical material. After that, the curable liquid material is cured, and the optical material is processed in the state, and a method for processing an optical element. 2. The method for processing an optical element according to claim 1, wherein the curable liquid material is a thermoplastic material. 3. The method of processing an optical element according to claim 1, wherein the curable liquid material is a reaction-curable elastic material. 4. Before the space between the holding member holding the optical material and the optical material is filled with the curable liquid material, a coating film made of a reaction-curable elastic material is previously formed on the optical element. The method for processing an optical element according to claim 1, which is characterized in that.