JPH11151648A - Optical element holding method and holding jig - Google Patents

Abstract

(57) [Summary] [PROBLEMS] An optical element holding that can surely hold an optical element during polishing of the optical element, and does not cause scratches on an optical surface or burns due to a polishing liquid flowing around. A method and a holding jig are provided. SOLUTION: A portion near the outer periphery of a back surface 10b of an optical element 10 is supported by a ring-shaped first elastic body 12, and an optical element 1 is provided.
A plurality of ring-shaped second surfaces provided on the inside
To be supported by the elastic bodies 13 and 14, and
The optical element 10 is vacuum-sucked through the annular grooves 11d and 11e by the vacuum suction system to hold the optical element 10 in the thrust direction, and a plurality of clamps 16 are provided.
16, the outer peripheral edge surface 10c of the optical element 10 is pressed at a plurality of locations to hold the optical element 10 in the rotation direction and the radial direction, thereby causing scratches on the optical surface at the time of holding and causing burns due to the polishing liquid flowing around. The optical element can be reliably held without causing the optical element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element holding method and a holding jig used for polishing an optical element such as a spherical lens or an aspherical lens having two optical surfaces.

[0002]

2. Description of the Related Art Conventionally, in polishing an optical element having two optical surfaces, each surface is individually polished by a step of polishing and finishing a first surface and a step of polishing and finishing a second surface. In this case, at the time of polishing the second surface, the polishing is performed based on the first surface which has been polished and finished, but the means for bonding the jig based on the first surface which has been polished and finished by pitch or the like is used. It is common to hold the entire surface with a.

[0003] As another method, there is a method of mechanically holding by a collet chuck or the like.

[0004]

However, in the prior art as described above, when bonding is used, the polished surface that has already been polished is fixed to a jig via an adhesive, so that the adhesive layer When the thin portion comes into contact with the holding jig, a scratch is generated, and when dust or the like is mixed in the adhesive layer, the scratch may be caused by the dust or the like. Also,
Although it is necessary to remove the adhesive after polishing the second surface, a small scratch may occur when the adhesive is removed. For example, a high-precision surface roughness such as a surface through which light having a short wavelength passes. May be a problem on the optical surface where is required.

In the case of mechanically holding, when polishing the second surface, the polishing liquid flows around the already polished first surface, and the polishing liquid causes chemical deterioration (burn) on the polished surface. However, for example, there may be a problem on an optical surface that requires highly accurate surface roughness such as a surface through which an ultraviolet laser passes.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and can surely hold an optical element when polishing the optical element and can prevent scratches on an optical surface. It is an object of the present invention to provide an optical element holding method and a holding jig which do not cause generation of burns or burns due to a polishing liquid spill.

[0007]

In order to achieve the above object, an optical element holding method according to the present invention is directed to a holding method for holding an optical element when polishing an optical element whose front and back surfaces are optical surfaces. A portion near the outer periphery of the back surface of the surface to be polished is supported by a ring-shaped first elastic body, and further, a portion between the support portion of the first elastic body on the back surface of the optical element and the center of the optical element. A plurality of ring-shaped second elastic bodies can support the gap, and the back surface portion of the optical element that is not in contact with the first elastic body and the plurality of second elastic bodies is suctioned by vacuum. The optical element is held in the thrust direction, and the outer edge surface of the optical element is pressed at a plurality of locations to hold the optical element in the rotation direction and the radial direction.

In the optical element holding method of the present invention, the first elastic body supporting the back surface of the optical element is an O-ring, and the second elastic body is an elastic body having a lower hardness than the O-ring. Preferably, the second elastic body is positioned lower than the first elastic body with respect to the back surface shape of the optical element.

Further, in the optical element holding method of the present invention, polyurethane or synthetic leather is suitable as the second elastic body.

An optical element holding jig according to the present invention is a holding jig for holding an optical element whose front and back surfaces are optical surfaces, wherein the ring supports a portion near the outer periphery of the back surface of the polished surface of the optical element. A belt-shaped first elastic body, and the ring-shaped first elastic body;
A plurality of ring-shaped second elastic bodies that support the back surface of the polished surface inside the elastic body, and the second elastic body that is not in contact with the first elastic body and the plurality of second elastic bodies. A vacuum suction system opened in an annular groove provided to vacuum-suck the back surface portion of the polishing surface, and a plurality of clamps provided to press the outer peripheral edge surface of the optical element at each location. It is characterized by having.

In the optical element holding jig of the present invention, the second elastic body is preferably an elastic body having a lower hardness than the first elastic body, and the first elastic body is an O-ring. Preferably, the second elastic body is an elastic body having a lower hardness than the O-ring.

Further, in the optical element holding jig of the present invention, the second elastic body disposed inside is positioned lower than the first elastic body with respect to the back surface shape of the optical element. Is preferred.

Further, in the optical element holding jig of the present invention, polyurethane or synthetic leather is preferable as the second elastic body.

In the optical element holding jig according to the present invention, the clamp portion includes a pushing piece that contacts the outer peripheral face of the optical element and a pressing screw that presses the pushing piece against the outer peripheral face of the optical element. Is preferred.

[0015]

According to the present invention, only the first elastic body, the O-ring, and the second elastic body are in contact with the already polished back surface of the optical element, and the polished surface has already been polished. Does not scratch the surface. Further, the portion near the outer periphery of the optical element is supported by an O-ring or a first elastic body, and is held in the thrust direction by vacuum suction, whereby the holding in the thrust direction is performed, and the O-ring is provided on the already polished holding surface side. Etc. can prevent the polishing liquid from flowing around,
There is no occurrence of chemical deterioration (burn) caused by the already polished surface coming into contact with the polishing liquid.

Further, the inner elastic body has lower hardness and lower height than the elastic body supporting the outer periphery,
The support on the outer periphery is complete, the inside of the elastic support on the outer periphery is reliably vacuum-absorbed, the polishing liquid can be completely prevented, and the force applied to the optical element by the inner support is reduced. The holding deformation is also controlled.

When the optical element is polished, a force for rotating the optical element is generated by the polishing force, but the rotation direction and the radial direction are regulated by a clamp portion which presses the outer edge of the optical element. So fast,
Polishing at a high pressure becomes possible, and the efficiency of the polishing step can be improved.

[0018]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of an optical element holding jig according to the first embodiment of the present invention, and FIG. 2 is a plan view of the optical element holding jig according to the first embodiment of the present invention. A-A
It is sectional drawing along the line.

In FIGS. 1 and 2, reference numeral 10 denotes an optical element to be polished (hereinafter, referred to as a workpiece).
The upper surface 10a to be polished is a substantially convex spherical surface, and the lower surface (back surface)
Polishing has already been completed for the plane indicated by 10b. 1
Reference numeral 1 denotes a holding jig according to the first embodiment of the present invention, which has a ring-shaped convex portion 11a having a diameter slightly smaller than the diameter of the workpiece 10;
A convex portion 11b serving as a circular receiving surface provided at a central portion, and a circular receiving surface 11b and an annular convex portion 11a at a central portion.
And at least one orifice 11c serving as an orbicular receiving surface is formed between them, and the upper surface of the outermost orbicular annular protrusion 11a has an orbicular first sheet-like elasticity. Body 12
Is completely adhered, and a second sheet-like elastic body (for example, polyurethane or bontex, etc.) softer than the first elastic body 12 is provided on the upper surfaces of the central receiving surface 11b and the annular receiving surface 11c. Synthetic leathers) 13 and 14 are respectively attached, and these first and second elastic bodies 12 and 1 are attached.
Reference numerals 3 and 14 support the back surface 10 b of the workpiece 10. Then, for example, the upper surfaces of the polyurethane sheets 13 and 14 as the second elastic body are
The shape of the back surface is set to be slightly lower than the upper surface of the elastic sheet 12. That is,
The back surface 10b of the workpiece 10 has a ring-shaped first elastic body 12
When the work piece 10 is placed on the rear surface, the back surface 10b of the workpiece 10 does not come into contact with the central polyurethane sheet 13 and the annular polyurethane sheet 14, and a small gap is interposed therebetween.

A portion of the holding jig 11 which is not the receiving surface of the workpiece 10, that is, an annular groove portion 11 d located between a central circular receiving surface 11 b and an annular convex portion 11 c, An opening 15 for vacuum suction is provided in an annular groove 11e located between the annular convex portion 11a and the annular convex portion 11c.
d and 15e are respectively opened and communicate with a vacuum source suction connector 15g provided on the outer peripheral portion of the holding jig 11 via a path 15f inside the holding jig 11 and a vacuum device (not shown). Linked to

The holding jig 11 has a plurality of clamp portions 16 on the outer side of the outermost ring-shaped convex portion 11a for abutting the outer periphery of the workpiece 10 and fixing the workpiece 10. ,
16 are further provided. Each clamp 16
As shown in FIGS. 1 and 2, a push piece 17 formed in an arc shape similar to the outer peripheral cylindrical surface (edge face) 10 c of the workpiece 10, and a push for pressing the push piece 17 against the workpiece 10. It is composed of a pressure screw 18 and a fixing screw 19 for holding the push piece 17 from rising. In the present embodiment, the length of the arc of contact with the workpiece per one of the push pieces 17 is set to about 1/8 of the entire circumference of the workpiece, and the clamp portion 16 is connected to the outer circumference of the workpiece 10. The push pieces 17 can be individually fed to the workpiece 10 individually. This is for the purpose of exerting a fastening force such that the holding of the processing torque applied from the polishing tool during the polishing processing does not come off or the workpiece does not shift.

In each clamp portion 16, the push piece 17 has an arc-shaped concave surface 17a formed on the inner side surface of the workpiece 10 which is in contact with the outer peripheral surface 10c, and penetrates in the radial direction. A plurality of (three in the illustrated example) slits 17b are formed, and a fixing screw 19 is inserted into each of the slits 17b.
Is screwed to the holding jig 11. The fixing screw 19 suppresses the lifting of the pushing piece 17 and
To guide the radial movement of. The pressing screw 18 is screwed into each of a plurality of (three in the illustrated example) screw holes 11h provided in a rising portion 11g provided on the outer peripheral portion of the holding jig 11, and a push piece is formed at the tip end thereof. The push piece 17 is pressed inward by contacting the outer surface of the push piece 17.

Next, a description will be given of a holding method for holding a workpiece using the holding jig of the present embodiment configured as described above.

A workpiece 10 such as a lens material having a flat back surface (lower surface) 10b is placed on the upper surface of the holding jig 11, that is, the first sheet-like elastic body 1 on the outermost annular convex portion 11a.
Put on top of 2. At this time, the back surface 10b of the workpiece 10
Are the central circular receiving surface 11b and the annular receiving surface 1
Instead of abutting the respective polyurethane sheets 13, 14 on 1c, there is a slight gap between them. Then, the workpiece 1 is clamped by the outer peripheral clamp portions 16, 16.
The workpiece 10 is temporarily fixed by pressing the outer peripheral edge surface 10c of 0. Next, a vacuum device (not shown) is connected to the vacuum source suction connector 15g to operate the vacuum device. Then, the back surface of the workpiece 10 is sucked through the annular grooves 11d and 11e, and the workpiece 10 is pulled down as a whole, and the first workpiece 10 on the outermost annular ridge 11a is formed.
The sheet-like elastic body 12 is crushed and functions as a seal on the back surface, and the back surface 10b of the workpiece 10 has the polyurethane sheet 13 and 14 of the center circular receiving surface 11b and the annular receiving surface 11c, respectively. The workpiece 10 such as a lens material is firmly fixed to the holding jig 11 in both the vertical direction (thrust direction) and the circumferential direction.

The already polished back surface 1 of the workpiece 10
Only the first and second elastic bodies 12, 13, 14 are in contact with Ob, and these elastic bodies 12, 13, 14
The hardness of the workpiece 10 is lower than that of the workpiece to be polished, so that the already polished back surface 10b is not damaged, and a portion close to the outer periphery of the workpiece 10 is
The support in the thrust direction and the vacuum suction in the thrust direction maintain the thrust direction, and the sealing action of the first elastic body 12 prevents the polishing liquid from flowing around the already polished back surface 10b side. No chemical deterioration (burn) occurs when the already polished surface comes into contact with the polishing liquid.

Further, the inner second elastic bodies 13 and 14
The first elastic body 12 supporting the outer circumference has a lower hardness and a lower height, so that the outermost first elastic body 12 is completely supported by the outermost first elastic body 12, and the inside of the supporting portion is a vacuum. Adsorption is ensured and spillage of the polishing liquid is completely prevented. In the rotating direction, a force to rotate the workpiece 10 is generated by the polishing force. However, the rotating direction and the radial direction are regulated by the clamp 16 which presses the outer edge 10 c of the workpiece 10. Therefore, high-speed and high-pressure polishing can be performed, and the efficiency of the polishing process can be improved.

Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 3, reference numeral 20 denotes a workpiece to be polished, and an upper surface 20a to be polished has a substantially concave spherical surface.
Polishing of the convex spherical surface indicated by 20b on the lower surface (back surface) has already been completed. Reference numeral 21 denotes a holding jig according to the second embodiment of the present invention, which is a ring-shaped convex portion 21a having a diameter slightly smaller than the diameter of the workpiece 20, and a convex portion serving as a circular receiving surface provided at the center. 21b and at least one convex portion 21c which is provided between the circular receiving surface 21b at the center and the annular convex portion 21a and serves as an annular receiving surface is formed. An annular groove 21f is engraved on the upper surface of the belt-shaped convex portion 21a, and an O-ring 22 is fitted into the groove 21f.
It is configured to be higher than the upper surface of 1a. On the upper surfaces of the circular receiving surface 21b and the annular receiving surface 21c at the center, a second sheet-like elastic body (for example, synthetic leather such as polyurethane or bontex) 23 which is softer than the O-ring 22; 24 are attached to each other, for example, a polyurethane sheet 23 as a second elastic body,
24 is formed so as to have a concave surface shape corresponding to the convex spherical surface of the back surface 20b of the workpiece 20, and the back surface 20b of the workpiece 20 when the O-ring 22 supports the workpiece 20. Is set so that there is a slight gap.

A portion of the holding jig 21 which is not the receiving surface of the workpiece 20, that is, an annular groove portion 21 d located between a central circular receiving surface 21 b and a ring-shaped convex portion 21 c, An opening 25 for vacuum suction is formed in an annular groove 21e located between the annular convex portion 21a and the annular convex portion 21c.
d and 25e are respectively opened, and these are communicated via a path 25f inside the holding jig 21 with a vacuum source suction connector 25g provided on an outer peripheral portion of the holding jig 21. Linked to

The holding jig 21 has a plurality of clamps 26, 26 on the outer side of the outermost annular ridge 21a for fixing the workpiece 20 by contacting the outer periphery of the workpiece 20. …
Is further provided. The clamp portion 26 is provided on the outer peripheral edge surface 2 of the workpiece 20 similarly to the first embodiment.
0c, a pressing piece 27 formed in the same arc shape as that of 0c, a pressing screw 28 for pressing the pressing piece 27 against the workpiece 20,
And a fixing screw 29 for holding the push-piece 27 up. A detailed description of the clamp unit 26 is omitted.

Next, a description will be given of a holding method for holding a workpiece using the holding jig of the present embodiment configured as described above.

A workpiece 20 such as a lens material having a convex back surface (lower surface) 20b is placed on the upper surface of the holding jig 21, that is, on the O-ring 22 on the outermost ring-shaped convex portion 21a. At this time, the back surface 20b of the workpiece 20 does not come into contact with the respective polyurethane sheets 23 and 24 on the central circular receiving surface 21b and the annular receiving surface 21c, and there is a slight gap between them. I do. The outer peripheral edge surface 20 c of the workpiece 20 is formed by the outer peripheral clamp portions 26, 26.
To temporarily fix the workpiece 20. Next, a vacuum device (not shown) is connected to the vacuum source suction connector 25g to operate the vacuum device. Then, the back surface of the workpiece 20 is sucked through the annular grooves 21d and 21e, the workpiece 20 is pulled down as a whole, and the O-ring 22 on the outermost annular ridge 21a is crushed. And the back surface 20b of the workpiece 20 is supported by the respective polyurethane sheets 23 and 24 of the central circular receiving surface 21b and the annular receiving surface 21c in the vertical direction (thrust direction). The lens material is firmly fixed to the holding jig in both the circumferential direction and the circumferential direction.

In the present embodiment, the portion near the outer periphery of the workpiece 20 is supported by the O-ring 22 and sucked in the thrust direction by vacuum, so that the holding in the thrust direction is performed. In addition, it is possible to prevent the polishing liquid from flowing around the already polished back surface 20b side, so that the already polished surface does not come into contact with the polishing liquid and does not cause chemical deterioration (burn). Further, the inner second elastic members 23 and 24 have a lower hardness and a lower height than the O-ring 22 supporting the outer periphery, so that the support by the outermost O-ring 22 becomes complete, The inside of the support is ensured by vacuum suction and the spilling of the polishing liquid can be completely prevented.

In this embodiment, one O-ring is used for sealing the back surface. However, two O-rings may be used to improve the reliability of the seal.

[0036]

The method for holding an optical element according to the present invention is configured as described above, so that the first polished back surface of the workpiece has a first elastic body, an O-ring, and other first and second O-rings. 2
Are in contact with each other, and the hardness of these elastic bodies and the like is lower than that of the optical element to be polished, so that the already polished surface is not damaged.

Further, a portion close to the outer periphery of the optical element is supported by a first elastic body such as an O-ring and vacuum-adsorbed in the thrust direction, so that the holding in the thrust direction is performed, and the holding surface side which has been polished is already used. Can prevent the polishing liquid from wrapping around due to the sealing action of the O-ring or the like, and does not cause chemical deterioration (burn) caused when the already polished surface comes into contact with the polishing liquid.

Further, the inner elastic body has lower hardness and lower height than the elastic body supporting the outer periphery,
The support on the outer periphery is complete, the inside of the elastic support on the outer periphery is reliably vacuum-absorbed, the polishing liquid can be completely prevented, and the force applied to the optical element by the inner support is reduced. The holding deformation is also controlled.

Further, in the rotating direction, a force for rotating the optical element is generated by the polishing force, but the rotating direction and the radial direction can be regulated by a clamp mechanism for pressing the outer edge of the optical element. Polishing at high speed and high pressure is possible, and the efficiency of the polishing process is improved.

As described above, the holding method and the holding jig of the optical element according to the present invention allow the optical element to be moved in the thrust direction.
Both the radial direction and the rotating direction can be reliably held, and the occurrence of scratches on the optical surface during holding and the occurrence of burns due to the flow of the polishing liquid do not occur.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical element holding jig according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the optical element holding jig according to the first embodiment of the present invention, taken along line AA of FIG.

FIG. 3 is a sectional view similar to FIG. 2 of a holding jig for an optical element according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10; 20 optical element (workpiece) 11; 21 holding jig 11a; 21a annular convex portion 11b; 21b central circular receiving surface (convex portion) 11c; 21c annular annular receiving surface (convex portion) 11d, 11e; 21d, 21e Annular groove portion 11g; 21g Rise portion 12 First sheet-like elastic body 22 O-ring 13, 14, 23, 24 Second sheet-like elastic body 15d, 15e; 25d, 25e Vacuum 26, 26 ... Clamping section 17, 17 ...; 27, 27 ... Push piece 18, 18 ...; 28, 28 ... Pressing screw 19, 19 ...; 29, 29 ... Fixing screw

Claims (11)

[Claims] 1. A holding method for holding an optical element when polishing an optical element whose front and rear surfaces are optical surfaces, wherein a portion near the outer periphery of the back surface of the polished surface of the optical element is formed by a ring-shaped first elastic body. Supporting, furthermore, between the support portion of the first elastic body on the back surface of the optical element and the center of the optical element can be supported by a plurality of ring-shaped second elastic bodies, The rear surface portion of the optical element that is not in contact with the first elastic body and the plurality of second elastic bodies is suctioned by vacuum to hold the optical element in the thrust direction, and the outer peripheral surface of the optical element An optical element holding method in which the light is pressed at a plurality of positions to hold the light in the rotational direction and the radial direction. 2. The optical element holding method according to claim 1, wherein the second elastic body supporting the back surface of the optical element is an elastic body having a lower hardness than the first elastic body. 3. The optical element according to claim 1, wherein the first elastic body supporting the back surface of the optical element is an O-ring, and the second elastic body is an elastic body having a lower hardness than the O-ring. Optical element holding method. 4. The optical element holding method according to claim 1, wherein the second elastic body is made of polyurethane or synthetic leather. 5. The optical device according to claim 1, wherein the second elastic body is positioned lower than the first elastic body with respect to the back surface shape of the optical element. Optical element holding method. 6. A holding jig for holding an optical element whose front and rear surfaces are optical surfaces, wherein the first elastic body has an annular shape and supports a portion of the polished surface of the optical element which is close to the outer periphery of the back surface.
A plurality of orbicular second elastic bodies supporting the back surface of the surface to be polished inward of the orbicular first elastic body, the first elastic body and the plurality of second elastic bodies, A vacuum suction system opened to an annular groove provided to vacuum-contact the back surface portion of the surface to be polished that is not in contact with the polishing surface, and an outer peripheral edge surface of the optical element were provided to be pressed at respective locations. An optical element holding jig having a plurality of clamp portions. 7. The optical element holding jig according to claim 6, wherein the second elastic body is an elastic body having a lower hardness than the first elastic body. 8. The optical element holding jig according to claim 6, wherein the first elastic body is an O-ring, and the second elastic body is an elastic body having a lower hardness than the O-ring. 9. The optical system according to claim 6, wherein the second elastic body disposed inside is positioned lower than the first elastic body with respect to the back surface shape of the optical element. The optical element holding jig according to claim 1. 10. The optical element holding jig according to claim 6, wherein the second elastic body is made of polyurethane or synthetic leather. 11. The clamping unit according to claim 6, wherein said clamp portion includes a push piece which abuts on the outer peripheral surface of said optical element and a pressing screw which presses said push piece against said outer peripheral surface of said optical element. The optical element holding jig according to any one of claims 10 to 10.