JPH09267246A - Optical raw material centering holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To center and hold a lens to be centered and edged without damaging it by forming its contact edge of a material softer than an optical raw material in a centering holder having a clamp part having on the tip the circular contact edge which can come into contact with a spherical surface of the optical raw material. SOLUTION: An installing part 12 of a lens holder 11 being a centering holder of a lens is formed of, for example, brass or the like, and has an almost thin cylindrical small diameter part 12a and an almost thick cylindrical large diameter part 12b. A clamp part 13 is composed of engineering plastic or the like, and is formed in an almost thin cylindrical shape, and is fitted to the small diameter part 12a of the installing part 12 from outside, and is fixed by adhesion between an inside surface 13b of the clamp part 13 and an outside surface of the small diameter part 12a of the installing part 12 and between a rear end surface 13c of the clamp part 13 and a front face 12e of the large diameter part 12b of the installing part 12. The lens is sandwiched and held between the opposed lens holders 11, and centering of the lens is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical material centering method for holding an optical material in a centering operation for aligning an optical axis of an optical material made of an optical material such as optical glass with a mechanical center line of a centering axis or the like. TECHNICAL FIELD The present invention relates to a holder for optical materials, and particularly to a holder for centering an optical material when performing centering by "bell clamp type centering".

[0002]

2. Description of the Related Art Conventionally, in the processing of optical materials, for example, in the case of producing a biconvex lens, the optical material made of an optical material including an optical glass such as a crown type glass and a flint type glass is taken and the lens surface is processed. The lens outer diameter is processed in this order. The material removing process is a process of roughly forming an optical material for one lens to obtain an optical material to be processed. The lens surface processing is performed in the order of rough processing, smoothing, and polishing (polishing).

[0003] Of these, the first roughing is a process for improving the surface roughness by bringing the dimensions of the optical material from which the material has been removed close to the final value of the lens, and by using "roughing" or "curve generator grinding". Done. The following smoothing process is
This is a process of making the surface roughness generated by the roughing process finer and adjusting the thickness dimension of the lens within the required accuracy, and is performed by "sanding" or "diamond smoothing". The final polishing process finishes the lens surface to an optical mirror surface,
This is a step of bringing the size and shape into the final precision, and is performed using a water slurry-like abrasive or the like.

[0004] The lens outer diameter processing is called "centering",
An optical material in which at least one of the two surfaces facing each other is polished into a spherical lens shape (hereinafter referred to as "centering lens") after the polishing step is completed is a "centering machine".
It is attached to a cylindrical grinding machine called "centering machine" and "centering" is performed to align the center axis of the cylindrical grinding process with the optical axis of the lens. Is a process for removing a lens to obtain a lens having a predetermined diameter. Therefore, in the first stage of lens processing, material processing is performed to a large diameter in consideration of a margin for centering in a designed diameter value. In this centering step, in addition to cutting out the correct outer diameter of the lens, chamfering of the lens outer peripheral portion, front chamfering, etc. are also performed.

As a centering method described above, the one shown in FIG. 3 is known. This centering method uses a method called "bell clamp type centering".
3A shows a state before centering by the bell clamp type centering, and FIG. 3B shows a state before centering and centering by the bell clamp method. In this bell clamp method, as shown in the figure, a centering machine having two substantially cylindrical metal spindles 41 and 42 is used. The spindles 41 and 42 share the same central axis A1 and are configured to be movable in the left-right direction in the drawing. This central axis A1 coincides with the central axis of the cylindrical grinding process in the centering machine (hereinafter referred to as "machine axis"). Further, male screw portions 41a and 42a are formed at the tip portions of the spindles 41 and 42 that face each other. Substantially cylindrical lens holders 31 and 32 are prepared for the spindles 41 and 42, respectively, and female screw portions 31a and 32a are formed at the rear portions of the lens holders 31 and 32, respectively. Therefore, the male screw portion 41a or 42a is attached to the female screw portion 31a.
Alternatively, the lens holders 31 or 32 can be mounted on the spindles 41 or 42 by screwing 32a, so that the central axes of the lens holders 31 and 32 are coaxial. Further, the lens holder 31 or 32 can be detached from the spindle 41 or 42 by loosening the screwing of both. Further, the front portions 31b and 32b of the lens holders 31 and 32 facing each other are formed so as to form a conical surface toward the inner hole of the cylinder, and the taper angle of the cross section of the conical surface is, for example, about 45 degrees. Is set to. Therefore, the front ends of the front portions 31b and 32b of the lens holders 31 and 32 are circular edge-shaped contact edges.

First, the centering of the lens is performed by the centering device having the above-mentioned configuration. Therefore, as shown in FIG. 3A, the pre-centering lens L for which the lens surface processing up to the polishing processing is completed is inserted between the lens holders 31 and 32. In this case, the pre-centering lens L has spherical lens surfaces S1 and S1.
2, the radius of curvature of the lens surface S1 is R1 and the center of curvature is at O1. The radius of curvature of the lens surface S2 is R2, and the center of curvature is at O2. The true optical axis of the lens L is A2, but the center axis of the outer diameter of the lens L is A3 before centering, and the two do not match.

Next, as shown in FIG. 3B, both sides of the pre-centering lens L are sandwiched by lens holders 31 and 32,
When the contact edges of the front ends 31b and 32b of the lens holders 31 and 32 are brought into contact with the lens surfaces S1 and S2 and pressed with a predetermined force, the lens surface S2 is spherical and the lens holder 3
No. 1 is in line contact with the abutting edge of the front portion 31b, and the contact line is a circle, and the lens surface S1 is spherical and has a line contact with the abutting edge of the front portion 32b of the lens holder 32, and the contact line is a circle. Therefore, the pre-centering lens L moves to a position where the optical axis A2 thereof coincides with the processing machine axis A1 which is the central axis of the centering machine, and then stabilizes at that position. That is, centering is automatically performed by the sliding movement of the lens itself.

In this state, if unnecessary peripheral portions C1 and C2 of the pre-centering lens L are ground by the centering machine by a required amount, the lens diameter which was D1 before the centering is changed to the required lens diameter D2. can do. After centering, the center axis of the outer diameter of the lens L coincides with the optical axis A2 of the lens L.

[0009]

However, in the above-described conventional centering method, since the lens holders 31 and 32 used for clamping the lens are formed of a metal material such as brass, the optical material of the lens is a soft material. In this case, there is a problem in that the lens surface is damaged by the circular contact edge of the tip of the lens holder.

In order to solve the above problems, thin paper having a thickness of about 0.02 mm was attached to both surfaces of the pre-centering lens to prevent scratches on the lens. In addition to increasing the number of processes, the thin paper is interposed between the lens and the lens holder, so that even if both sides of the lens are sandwiched between the lens holders and pressed, the lens does not slide smoothly and the centering accuracy is reduced. There was a problem.

For this reason, when both lens holders were formed of a synthetic resin material for centering, the lenses were not scratched and the centering accuracy was within a predetermined value. However, in this case, the female screw portion 31 at the rear of the lens holder is
The portions a and 32a are also made of synthetic resin. Therefore, the synthetic resin female screw portion 31 at the rear of the lens holder is used.
The a and 32a are more deformed than the metal spindles 41 and 42. Therefore, in order to perform centering of other types of lenses, the lens holders 31 and 32 are attached to the spindle 41,
Once removed from 42 and screwed again, the meshing state of the female threaded portions 31a, 32a at the rear of the lens holder and the male threaded portions 41a, 42a of the spindle changes to a meshing state different from the initial meshing state, A small eccentricity or declination occurs between the center axes of the lens holders 31 and 32 and the spindles 41 and 42, which causes a problem of poor reproducibility that the initially obtained centering accuracy cannot be obtained. did.

The present invention has been made in order to solve the above problems, and the problems to be solved by the present invention are as follows. Another object of the present invention is to provide a bell clamp type optical material centering holder capable of preventing the centering accuracy from being lowered due to attachment / detachment to / from the spindle of the centering machine.

[0013]

In order to solve the above-mentioned problems, the optical material centering holder according to the present invention is made of an optical material, and at least one of the two surfaces facing each other is processed into a spherical shape. In a holder for optical material centering, which comprises a clamp part having a circular contact edge capable of contacting the spherical surface of the optical material at its tip, and a mounting part detachable from the centering device, The contact edge is formed of a first material that is softer than the optical material, and the mounting portion is formed of a second material that is less deformed before and after being attached to and detached from the centering device.

In the above-mentioned optical material centering holder,
Preferably, the first material includes a synthetic resin material.

In the above optical material centering holder, preferably, the second material contains a metal material or a ceramic material.

In the optical material centering holder described above, preferably, the front portion of the mounting portion is formed in a substantially cylindrical shape and projects toward the clamp portion, and the clamp portion is in front of the mounting portion. It is formed in a substantially cylindrical shape having an inner diameter slightly larger than the outer diameter of the portion, and is externally fitted and fixed to the clamp portion.

Further, in the above-mentioned optical material centering holder, preferably, the clamp portion is formed in a substantially cylindrical shape, and is fixed to a front portion of the mounting portion.

[0018]

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

(1) First Embodiment FIG. 1 shows the configuration of a first embodiment of the optical material centering holder according to the present invention, and shows the centering of the lens. The upper half of the figure shows a side view, and the lower half of the figure shows a cross-sectional view of that portion. As shown in FIG. 1, a lens holder 11 which is a holder for centering an optical material includes a mounting portion 12 and a clamp portion 13.

The mounting portion 12 is made of a metal material which is a second material,
For example, a thin portion 1 formed of brass or the like and having a substantially thin cylindrical shape
2a and a large-diameter portion 12b having a substantially thick cylindrical shape. The small diameter portion 12a projects forward toward the clamp portion 13. The large diameter portion 12b has an outer diameter larger than the outer diameter of the small diameter portion 12a, and is connected to the rear portion of the small diameter portion 12a. Further, inside the mounting portion 12, the small diameter portion 12a and the large diameter portion 12 are
A through hole 12d that penetrates b is formed. Large diameter part 1
A female threaded portion 12c is formed on the inner surface of the rear through hole of 2b, and the female threaded portion 12c can be attached to and detached from the spindle 41 or 42 of the centering machine shown in FIG. 3 by screwing. .

The front portion of the small diameter portion 12a is formed to have a conical surface shape toward the through hole 12d inside the cylinder, and the taper angle of the cross section of the conical surface 12g is, for example, about 45 degrees. Is set to. The front surface 12e of the large diameter portion 12b is formed in a flat surface shape orthogonal to the axis of the cylinder.

The clamp portion 13 is made of a synthetic resin material which is the first material, for example, engineering plastic such as polyacetal, and is formed in a substantially thin cylindrical shape. The rear end surface 13c of the clamp portion 13 is formed in a flat surface shape orthogonal to the axis of the cylinder. Further, the inner diameter of the clamp portion 13 is the same as that of the small diameter portion 12 in front of the mounting portion 12 described above.
It is set to be slightly larger than the outer diameter of a. With such a configuration, the clamp portion 13 has the above-described mounting portion 1
2 is fitted from the outside into the small diameter portion 12a, and the clamp portion 13
The inner surface 13b of the mounting portion 12 and the outer surface of the small diameter portion 12a of the mounting portion 12, and the rear end surface 13c of the clamp portion 13 and the front surface 12e of the large diameter portion 12b of the mounting portion 12 are bonded and fixed.

The front portion of the clamp portion 13 is formed to have a conical surface shape toward the through hole 12d inside the cylinder, and the taper angle of the cross section of the conical surface 13a is, for example, about 45 degrees. It is set. In addition, the clamp portion 13
The conical surface 13a at the front part of is connected to the conical surface 12g at the front part of the small-diameter portion 12a to form one conical surface. Also,
The tip of the clamp portion 13 is a contact edge 13d having a circular, pointed edge shape. The roundness of the contact edge 13d is 2μ.
It is set to be m or less.

Next, a method for manufacturing the lens holder 11 of the above-described first embodiment will be described. First, prepare a cylindrical material made of a metal material such as brass, and use a processing machine such as a lathe to form a thin diameter front part and a large diameter rear part by cutting, and the inside of the cylindrical material inside A metal member having a through hole is formed. The front portion of the metal member is a portion that becomes the small diameter portion 12a of the mounting portion 12 in FIG. 1, and the rear portion of the metal member is the portion that becomes the large diameter portion 12b of the mounting portion 12 in FIG. Further, the through hole inside the metal member is a portion that becomes the through hole 12d in FIG.
Then, a female screw portion is formed on the rear inner surface of the through hole. This female screw portion is the female screw portion 12c of the mounting portion 12 in FIG.
It is the part that becomes. In this case, the length of the front portion of the metal member is set to be slightly longer than the length of the clamp portion 13 shown in FIG.

Next, a synthetic resin material such as engineering plastic is used to form a cylindrical resin member by injection molding or the like. This resin member is a portion that becomes the clamp portion 13 in FIG. In this case, the inner diameter of the resin member is set to be slightly larger than the outer diameter of the front portion of the metal member described above, and the length of the resin member is the same as the length of the front portion of the small diameter described above. Set to.

Next, an adhesive is applied to the inner surface and the rear end surface of the above resin member, the front portion of the metal member is fitted from the outside, and the front outer surface and the rear front surface of the metal member are adhered and fixed. In this state, the contact edge 13d, the conical surface 13a, and the conical surface 12g shown in FIG. 1 can be formed by tapping the front end surface of the metal member and the front end surface of the resin member in a tapered shape.
In this way, the lens holder 11 can be created.

Therefore, the lens holder 11 of the first embodiment is different from the above-mentioned conventional lens holder 31 in that
The contact edge 13d at the tip of the lens holder 11 is formed of a synthetic resin material, and the female screw portion 12c of the mounting portion that is attached to and detached from the centering machine is formed of a metal material, and is configured as a "hybrid member". It is in.

By the above-described bell clamp type centering, the two lens holders 11 and 11 are centered so that the contact edges 13d face the pre-centering lenses, for example, the two surfaces L shown in FIG. It is attached to the spindle of the machine, for example, 41 and 42 shown in FIG. Then, the lens holder 11,
By sandwiching and holding the pre-centering lens between 11, the optical axis of the pre-centering lens is automatically aligned with the processing machine axis by the above-described principle, and centering is performed. While maintaining this centered state and grinding the outer peripheral portion with a diamond tool or the like while rotating the lens before centering, the outer diameter of the lens can be set to a desired value and the center axis of the outer diameter of the lens can be adjusted. Can be aligned with the optical axis. As a result of the test processing, the centering accuracy (eccentricity between the lens outer diameter center axis and the lens optical axis) by the lens holder 11 of the first embodiment is 20 degrees.
It was within seconds.

Further, the lens holder 1 of the first embodiment
In No. 1, the contact edge 13d at the tip of the lens holder 11 is made of a synthetic resin material. Since synthetic resin materials are generally softer than optical materials such as optical glass, the optical materials are not damaged when they are pressed. Therefore, even if the pre-centering lens is clamped from both sides by the lens holder 11, neither lens surface is damaged.
About 100 pieces were tested and processed, but no scratches were found.

On the other hand, the lens holder 1 of the first embodiment
1, the female screw portion 12c provided on the rear mounting portion of the lens holder 11 is made of a metal material. Therefore, unlike a synthetic resin material, it does not undergo a large deformation,
Even when the lens holder 11 is mounted by screwing it into the male thread of the spindle of the centering machine and then detached, and then mounted again, the male thread of the spindle and the female thread of the mounting section are always in the same meshing state. Can be reproduced. Therefore, even if the lens holder 11 is repeatedly attached to and detached from the spindle of the centering machine, the centering accuracy does not decrease, and it is possible to always reproduce a predetermined centering accuracy. As a result of the test, with respect to this accuracy reproducibility, it was possible to obtain almost the same centering accuracy before and after the attachment / detachment of the lens holder.

(2) Second Embodiment Next, a second embodiment of the present invention will be described. FIG.
Shows a configuration of a second embodiment of a holder for centering an optical material of the present invention, wherein the upper half of the figure is a side view and the lower half of the figure is a cross-sectional view of the part. Shows. As shown in FIG. 2, the lens holder 21, which is a holder for centering the optical material, includes a mounting portion 22 and a clamp portion 23.

The mounting portion 22 is made of a metal material which is a second material,
For example, it is formed of brass or the like into a substantially thick-walled cylindrical shape.
Further, a through hole 22d is formed inside the mounting portion 22. A female screw portion 22c is formed on the inner surface of the through hole at the rear of the mounting portion 222, and the female screw portion 22c is
The spindle 41 or 42 of the centering machine shown in FIG.

The front surface 22e of the mounting portion 22 is formed in a flat surface shape orthogonal to the axis of the cylinder. This front 22
An annular groove 22f is formed on e.

The clamp portion 23 is made of a synthetic resin material which is the first material, for example, engineering plastic such as polyacetal, and is formed in a substantially thin cylindrical shape. The rear end surface 23c of the clamp portion 23 is formed in a flat surface shape orthogonal to the axis of the cylinder. Further, the through hole 23 e in the clamp portion 23 is the through hole 22 in the mounting portion 22.
It communicates with d. The rear portion of the clamp portion 23 has an annular groove 2 provided on the front surface 22e of the mounting portion 22 described above.
2f, and between the rear end surface 23c of the clamp portion 23 and the inner bottom surface of the annular groove 22f of the mounting portion 22, and the inner and outer side surfaces adjacent to the rear end surface 23c of the clamp portion 23 and the mounting portion 2
It is adhered and fixed between the inner surface of the second annular groove 22f.

The front portion of the clamp portion 23 is formed so as to have a conical surface shape toward the through hole 23e inside the cylinder, and the taper angle of the cross section of the conical surface 23a is, for example, about 45 degrees. It is set. In addition, the clamp portion 23
Has a contact edge 23d in the shape of a circular pointed edge. The roundness accuracy of the contact edge 23d is the same as that of the first embodiment.

Next, a method of manufacturing the lens holder 21 of the second embodiment described above will be described. First, a columnar material made of a metal material such as brass is prepared, and the inside of the columnar material is bored by a processing machine such as a lathe to manufacture a metal member having a through hole formed therein. The front surface of this metal member is a portion that becomes the front surface 22e of the mounting portion 22 in FIG. Further, the through hole inside the metal member is a portion that becomes the through hole 22d in FIG. Next, an annular groove is formed on the front surface of the metal member. The annular groove on the front surface of the metal member is a portion that becomes the annular groove 22f on the front surface 22e of the mounting portion 22 in FIG. Then, a female screw portion is formed on the rear inner surface of the through hole. This female screw portion is a portion that becomes the female screw portion 22c of the mounting portion 22 in FIG.

Next, a synthetic resin material such as engineering plastic is used to form a cylindrical resin member by injection molding or the like. This resin member is a portion that becomes the clamp portion 23 in FIG.

Next, an adhesive is applied to the rear end surface of the resin member and the inner and outer side surfaces adjacent to the rear end surface, fitted into the annular groove on the front surface of the metal member, and adhered to the inner bottom surface and the inner side surface of the annular groove. To fix. In this state, the contact edge 23 shown in FIG. 2 is formed by tapping the front end surface of the resin member in a tapered shape.
d and the conical surface 23a can be formed. In this way, the lens holder 21 can be manufactured.

Therefore, the lens holder 21 of the second embodiment is different from the above-mentioned conventional lens holder 31 in that
The contact edge 23d at the tip of the lens holder 21 is formed of a synthetic resin material, and the female screw portion 22c of the mounting portion that is attached to and detached from the centering machine is formed of a metal material, similar to the case of the first embodiment. , It has a hybrid structure.

Therefore, also in the case of the lens holder 21 of the second embodiment, as in the case of the first embodiment described above, the centering and the outer peripheral portion grinding by the bell clamp method described above can be easily performed. You can take care of yourself.
In this case, the position adjustment accuracy of the lens holders on both sides of the lens, the value of the bell clamp pressure, and the like are the same as those in the above-described first embodiment.

The lens holder 21 of the second embodiment is also the same as the lens holder 21 of the first embodiment.
The contact edge 23d at the tip of No. 1 is made of a synthetic resin material that is softer than an optical material such as optical glass. Therefore, even if both are pressed during the bell clamp, neither lens surface is scratched.

On the other hand, the lens holder 2 of the second embodiment
Also in the case of 1, the female screw portion 22c provided on the mounting portion on the rear side of the lens holder 21 is formed of a metal material that does not significantly deform. Therefore, even if it is repeatedly attached to and detached from the spindle of the centering machine, it is possible to always reproduce the same meshing state between the male screw of the spindle and the female screw of the mounting portion, and always reproduce the predetermined centering accuracy. You can

The present invention is not limited to the above embodiments. Each of the above embodiments is merely an example, and has substantially the same configuration as the technical idea described in the claims of the present invention, and those having the same functions and effects are:
Anything is included in the technical scope of the present invention.

For example, in each of the above-described embodiments, a biconvex lens is described as an example of a pre-centering lens that is held by a lens holder that is a holder for centering an optical material and is subjected to centering processing. The invention is not limited to this, and may be any lens as long as at least one surface is a spherical lens, and a lens having another shape, for example, a biconcave lens, one surface is convex and the other surface is concave. It may be a meniscus lens or the like. Further, not only the centering processing of the lenses but also the bonding work of the lenses may be performed, and further, not only the lenses but also the centering / centering of optical materials such as spherical mirrors can be applied.

However, whether or not centering can be performed by the above-mentioned Bell clamp method depends on the value of Z represented by the following formula: Z = [(r1 / R1) ± (r2 / R2)] / 2. This value Z is "centering coefficient"
That. In the above equation, [] indicates an absolute value symbol, R1 and R2 are the radii of curvature of the respective lens surfaces S1 and S2 in FIG. 3, and r1 is the tip of the lens holder 32 that contacts the lens surface S1 in FIG. The radius of the circle at the contact edge is r2
Is the lens holder 3 that contacts the lens surface S2 in FIG.
The radius of the circle of the abutting edge at the tip of No. 1 is shown respectively.
If the centering lens is a biconvex lens or a biconcave lens, the positive sign of the positive and negative compound signs in the above formula is adopted.If the centering lens is a meniscus lens, the positive and negative signs in the above formula are used. Adopt the negative number of the double number. In order to perform centering by the Bell clamp method, the centering coefficient value Z expressed by the above equation needs to be about 0.15 or more. This is because the centering of the bell clamp method uses the sliding motion between the contact edge of the lens holder and the lens, and depends on the coefficient of friction between the two.

Further, in each of the above-described embodiments, an example in which the tip of the lens holder, which is a holder for centering the optical material, is formed so as to have a conical surface shape toward the inner hole of the cylinder, is described. The invention is not limited to this, and may have any shape as long as the tip of the holder for optical material centering can be in line contact with the lens in a circular line. The tip may have a conical surface shape when facing the outside or the inside of the cylinder, and may be formed to have a V-shaped cross section. Alternatively, the optical material centering holder may be formed so that the cross section of the tip end thereof has a smooth “U” shape. Further, when centering the biconcave lens, the tip of the optical material centering holder is formed so as to form a conical surface toward the outside of the cylinder, contrary to the case of each of the above embodiments. Good.

Further, in each of the above-described embodiments, the synthetic resin material such as engineering plastic has been described as an example of the first material forming the contact edge of the lens holder which is the holder for centering the optical material. The present invention is not limited to this, and any material can be used as long as it is softer than the optical material that constitutes the precentering lens, which is an optical material, and does not scratch the lens surface during the bell clamp. Alternatively, another material, for example, a composite material containing a synthetic resin, a material obtained by forming a thin film (coating) with another material on the surface of a metal material, or the like may be used.

Further, in each of the above-described embodiments, an example has been described in which the entire clamp portion of the lens holder which is the holder for centering the optical material is made of the soft material such as the synthetic resin material which is the first material. , The present invention is not limited to this, it is sufficient that at least the contact edge portion of the tip of the optical material centering holder is formed of a soft material,
The main body portion and the contact edge of the clamp portion may be formed by another member and joined together.

In each of the above embodiments, brass is taken as an example of the second material forming the mounting portion of the lens holder which is the holder for centering the optical material, but the present invention is not limited to this. However, any material may be used as long as it has a small deformation before and after attachment / detachment to / from the spindle of the centering machine.Other materials, for example, other metal materials such as soft iron and steel, nitride and It may be a ceramic material such as carbide.

Further, in each of the above-described embodiments, screwing by screws is taken as an example of means for attaching / detaching the lens holder, which is a holder for optical material centering, to / from the spindle of a centering machine, which is a cylindrical grinding machine. However, the present invention is not limited to this, and any mechanical attaching / detaching means may be used, and other types of attaching / detaching means, for example, in the above-described embodiments, the spindle side is the female screw and the lens is used. The holder side may be a male screw, or the type in which a recess is provided at one end and the other is inserted and the periphery is tightened or loosened by bolts or the like to be attached or detached.

Further, in each of the above-described embodiments, an example in which the entire mounting portion of the lens holder, which is the optical material centering holder, is made of the metal material which is the second material has been described. However, it is sufficient that at least the female screw portion (attachment / detachment means) of the mounting portion is formed of a material that is small in deformation before and after attachment / detachment to / from the spindle of the centering machine. The female screw portion (attachment / detachment means) may be formed and joined by another member.

Further, in each of the above-mentioned embodiments, as the lens holder which is the holder for centering the optical material, the one in which the cylindrical member is combined is taken as an example, and the one having the through hole therein is described. Is not limited to this, and may have a minimum concave portion for forming an abutting edge and a minimum concave portion for forming a female screw portion for attaching / detaching to / from the spindle. The conical surface and its vicinity, or the vicinity of the female screw portion of the mounting portion may be formed in a blind hole shape so as not to penetrate.

In each of the above embodiments, as a method for forming the vicinity of the contact edge of the tip of the clamp portion of the lens holder which is the holder for centering the optical material, an example of cutting after adhering and fixing to the mounting portion However, this is because the accuracy of the abutment edge and the central axis is taken into consideration.
The present invention is not limited to this, and as long as the manufacturing accuracy can be ensured, a clamp part having a contact edge preprocessed may be adhesively fixed to the mounting part.

Further, in each of the above-described embodiments, an example has been described in which the lens holder, which is a holder for centering the optical material, is clamped from both sides in the horizontal direction of the pre-centering lens, that is, from the left and right directions. The optical axis of the pre-centering lens is oriented in the vertical direction, and the lens holder, which is a holder for optical material centering, is clamped from both sides in the vertical direction of the pre-centering lens, that is, the vertical direction. Good.

[0055]

As described above, according to the optical material centering holder according to the present invention, in the optical material centering holder by the bell clamp method, the abutting edges that press the lens surfaces while sandwiching each lens surface. Softer than optical materials that take care of
Since the mounting part that is made of a material and that is attached to and detached from the cylindrical grinding machine that performs centering is made of the second material that has a small deformation before and after attachment and detachment, scratches the lens surface for centering. Therefore, the sliding movement of the lens at the time of centering is smooth, and the predetermined centering accuracy can be consistently reproduced by repeatedly attaching and detaching the lens to and from the cylindrical grinder.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a configuration of a lens holder according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing a configuration of a lens holder according to a second embodiment of the present invention.

3A and 3B are views for explaining a conventional centering method for a lens. FIG. 3A shows a state before centering by a bell clamp method, and FIG. 3B shows centering by a bell clamp method. It shows up to taking each.

[Explanation of symbols]

 11 lens holder 12 mounting portion 12a small diameter portion 12b large diameter portion 12c female screw portion 12d through hole 12e front surface 12g conical surface 13 clamp portion 13a conical surface 13b inner wall surface 13c rear end surface 13d contact edge 21 lens holder 22 mounting portion 22c female Screw part 22d Through hole 22e Front face 22f Groove 23 Clamp part 23a Conical surface 23c Rear end face 23d Contact edge 23e Through hole 31,32 Lens holder 31a, 32a Female screw part 31b, 32b Front part 41, 42 Spindle 41a, 42a Male screw Part A1 Processing machine axis A2 Optical axis of lens before centering A3 Outer diameter center axis of lens before centering C1, C2 Grinding part D1 Lens diameter before centering D2 Lens diameter after centering L Lens before centering O1 Lens surface S1 Center of curvature O2 center of curvature of lens surface S2 R1 radius of curvature of lens surface S1 R2 lens Radius of curvature of surface S2 S1, S2 lens surface

Claims (5)

[Claims] 1. A clamp portion having at its tip a circular contact edge capable of contacting the spherical surface of an optical material, which is made of an optical material and at least one of two surfaces facing each other is processed into a spherical shape. An optical material centering holder including a mounting portion that is detachably attached to the centering device, wherein at least the abutting edge is softer than the optical material;
An optical material centering holder characterized by being formed of a material, and wherein the mounting portion is formed of a second material that is less deformed before and after being attached to and detached from the centering device. 2. The optical material centering holder according to claim 1, wherein the first material contains a synthetic resin material. 3. The optical material centering holder according to claim 1, wherein the second material includes a metal material or a ceramic material. 4. The optical material centering holder according to any one of claims 1 to 3, wherein the front portion of the mounting portion is formed in a substantially cylindrical shape in the direction of the clamp portion. The optical material centering is characterized in that the clamp portion is formed into a substantially cylindrical shape having an inner diameter slightly larger than the outer diameter of the front portion of the mounting portion, and the clamp portion is externally fitted and fixed to the clamp portion. Holder. 5. The optical material centering holder according to any one of claims 1 to 3, wherein the clamp portion is formed in a substantially cylindrical shape and is fixed to a front portion of the mounting portion. A holder for centering an optical material, which is characterized in that