CN1113728C - Clamp for grinding or polishing optical elements - Google Patents

Abstract

The invention discloses a jig for grinding or polishing an optical element, which includes a clamping piece and a cylindrical clamping seat, the clamping piece has a support surface, and the support surface is supported by an elastic layer to be ground or polished The contact surface of the optical element; the cylindrical clamping seat is installed around the clamping piece, and has an inner peripheral surface matched with the outer diameter of the optical element to clamp the outer peripheral surface of the optical element, and is characterized in that A concave surface is formed on a part of the inner peripheral surface of the holding seat, and this part is on the side of the contact surface of the optical element and is opposite to the outer peripheral edge of the outer peripheral surface of the optical element.

Description

Fixtures for Grinding or Polishing Optical Components

The present invention relates to an optical element jig for holding an optical element such as a lens, and more particularly to a jig for grinding or polishing an optical element, which holds the optical element such as a lens when grinding or polishing the optical element.

When an optical element such as a lens used in an optical instrument such as a camera or a video recorder is to be ground or polished, an optical element holder having a structure as shown in FIG. 7 is conventionally used to hold the optical element. The optical element holder 101 shown in Fig. 7 has a holder 102 made of a hard material and has a bearing surface 102a supporting an optical element L such as a lens, and a cylindrical holder 103 installed around the holder 102. , and the elastic layer 104 fixed on the supporting surface 102a of the clamping member 102 by bonding. The radius of curvature of the supporting surface 102a of the holding member 102 coincides with the radius of curvature of the contact surface La of the optical element L to be ground or polished, and a supporting member seat 105 is formed at the center portion of the surface of the supporting member opposite to the supporting surface 102a. . The inner diameter of the holding seat 103 matches the outer diameter of the optical element L to be ground or polished, and forms a continuous inner peripheral surface 103a for clamping the outer peripheral surface Lb of the optical element L mounted therein. When the optical element L is fitted in the optical element holder 101 , it is clamped by the inner peripheral surface 103 a of the cylindrical holding seat 103 while the contact surface La of the optical element is in contact with the elastic layer 104 .

When utilizing this type of optical element holder 101 to grind or polish the optical element L, the optical element L held by the optical element holder 101 is urged to contact a processing tool (not shown), such as a polishing plate with a radius of curvature to be processed, And press the optical element L with the pressure necessary for processing by a support (not shown; a rod-shaped member that can be engaged with the support holder 105), and the support is pressed against the support holder 105 of the clamping member 102 , while supporting the optical element holder 101 with the supporting member. When the processing tool is driven to rotate around its central axis while the support member swings, under the rotation of the processing tool and the guidance of the support member, the optical element holder 101 and the optical element L held by it have a curvature to be processed along the surface of the processing tool. The machining surface of the radius turns and swivels in an arc, thereby grinding or polishing the optical element L.

When the optical element L is ground or polished as described above, resistance is generated in the optical element L due to the frictional force on the processing surface of the processing tool. Therefore, a rotational difference occurs due to the rotation of the optical element L or a change in sliding between the contact surface of the optical element holder 101 and the optical element L during the rotation of the optical element L. As shown in FIG. This rotational difference causes wear. Also, there is a gap between the inner peripheral surface 103a of the holding seat 103 and the outer peripheral surface Lb of the optical element L. As shown in FIG. Thus, under the action of the swinging motion, the optical element L moves to one side of the optical element holder 101, and the above-mentioned behavior or similar motion of the optical element L in the swinging cycle produces an uneven impact on the outer peripheral surface Lb of the optical element L or similar. This can easily lead to edges or burrs. Then, even a very slight impact may cause undesired damage such as cracks or cuts on the outer peripheral edge Lc because the outer peripheral edge Lc of the optical element L is often brittle.

For this reason, some precautions need to be taken so that no impacts act on the fragile outer peripheral edge Lc of the optical element L during processing. For example, an optical element jig disclosed in Japanese Laid-Open Patent Publication No. 6-328355 is available as a technical solution in which such countermeasures are taken. Figure 8 shows such an optical element holder.

Referring to Fig. 8, the optical element fixture 111 has a clamping piece 112, a clamping seat 114 and an annular high-friction piece 116, the clamping piece 112 is used to support the optical element L through an elastic O-ring 113; the clamping seat 114 has a The groove of the clamping part 112 is used to support the clamping part 112 by the spring 115, so that the clamping part can move in the groove; the annular high friction part 116 is fixed on the inner peripheral surface of the groove of the clamping seat 114 distal and made of polyurethane or similar material. When the optical element L is to be ground or polished using this optical element holder 111, under the action of processing pressure, the outer peripheral ridge Lc of the optical element L supported by the clamp 112 through the elastic O-ring 113 is pressed against the high friction surface. on the slope of piece 116. A frictional force corresponding to the processing load and a high friction coefficient acts on the outer peripheral edge Lc of the optical element L to generate a high clamping force. Therefore, the optical element L can be securely held so as to be integrated with the optical element holder 111 . This structure can eliminate impact or the like on the outer peripheral edge Lc of the optical element L, or can alleviate such impact by shock absorption. Therefore, the optical element L can be processed without causing damage such as cracks or cuts on its outer peripheral edge Lc.

The conventional optical element holder shown in FIG. 8 is effective in avoiding cracks or cuts because it relieves impact or the like acting on the outer peripheral edge Lc of the optical element L. As shown in FIG. However, this makes the optical element holder 111 of this structure complicated and expensive. When a new optical element is to be mounted on the optical element holder 111, or when the high friction member 116 is to be replaced due to wear, the optical element must be clamped and adjusted. These fixings and adjustments are difficult to carry out. Since a complicated mechanism is introduced in the optical element holder 111, the thickness between the supporting member 119 supporting and pressing the optical element holder 111 and the optical element contact surface La increases. Then, the machining fulcrum through the support member 119 becomes high, possibly disturbing the machining balance, which is not desirable.

The present invention has been made in consideration of the unsolved problems of the above-mentioned prior art, and its object is to provide an optical element jig for clamping an optical element such as a lens when grinding or polishing the element, which can be reliably performed with a simple structure. Damage such as cracks, cuts or the like occurring in the outer circumferential edge of the optical element in the optical element holder can be avoided as much as possible.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a jig for optical element grinding or polishing, which includes a clamping piece and a cylindrical clamping seat, the clamping piece has a supporting surface, The supporting surface supports the contact surface of the optical element to be ground or polished through an elastic layer; the cylindrical clamping seat is installed around the clamping piece, and has an inner peripheral surface matched with the outer diameter of the optical element to clamp The outer peripheral surface of the optical element is characterized in that a concave surface (relief) is formed on a part of the inner peripheral surface of the holding seat, and this part is on the contact surface side of the optical element, and the outer peripheral edge of the outer peripheral surface of the optical element relatively.

According to a second aspect of the present invention, there is provided a jig for grinding or polishing an optical element, wherein the grinding or polishing tool is placed above the surface of the optical element to be processed, and the optical The element holder clamps the optical element, and it is characterized in that a clamping seat for regulating the outer peripheral surface of the optical element is provided in the optical element holder, and the optical element is clamped at one end opposite to the outer peripheral portion of the optical element A concave surface is formed in the seat, and a gap is formed between the optical element holding seat and the outer peripheral surface of the optical element.

With the jig for grinding or polishing an optical element of the present invention, a concave surface is formed in the portion of the inner peripheral surface of the jig opposite to the fragile outer peripheral edge of the optical element, so that the inner peripheral surface of the jig does not press against the edge of the optical element. Outer circumference edge. With this simple structure, even if repeated shocks are caused by abrasion or changing processes, machining or the like caused by slight backlash between the optics and the optics holder, such shocks will not damage the outer circumference of the optics. The ribs have a negative effect, so that no damages like cracks or cuts can form in the outer peripheral ribs of the optical element. Therefore, grinding or polishing of optical elements such as lenses can be performed stably.

Other objects and advantages than those discussed above will be apparent to those skilled in the art from the ensuing description of preferred embodiments of the invention. In the specification, reference is made to the accompanying drawings, which form a part hereof, and which schematically illustrate examples of the invention. These examples, however, are not exhaustive of the various embodiments of the invention, so reference is made to the claims appended hereto to determine the scope of the invention.

1 is a cross-sectional view showing a jig for grinding or polishing an optical element according to an embodiment of the present invention;

2 is a cross-sectional view showing a jig for grinding or polishing an optical element according to another embodiment of the present invention;

3 is a cross-sectional view showing a jig for grinding or polishing an optical element according to still another embodiment of the present invention;

4 is a cross-sectional view showing a jig for grinding or polishing an optical element according to still another embodiment of the present invention;

Fig. 5 is a view showing the shape of a convex clamp;

Fig. 6 is a view showing the shape of a concave clamp;

7 is a cross-sectional view of a traditional optical element grinding or polishing jig;

Fig. 8 is a cross-sectional view showing another conventional optical element grinding or polishing jig;

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

(first embodiment)

FIG. 1 is a cross-sectional view showing a jig for grinding or polishing an optical element according to an embodiment of the present invention.

A jig 1 for grinding or polishing an optical element shown in FIG. 1 has a holding member 2 , a cylindrical holding seat 3 and an elastic layer 4 . The holder 2 is made of a hard material such as metal and has a supporting surface 2a which supports an optical element such as a lens with a radius of curvature consistent with the contact surface La of the optical element L, and is formed in contact with the supporting surface 2a. The central part of the opposite support member surface forms the support member seat 5; the cylindrical holding seat 3 is installed around the holding member 2, and is made of a synthetic resin material such as polyacetal resin; the elastic layer 4 is fixed on the On the support surface 2a of the holder 2, so as to contact the contact surface La of the optical element L. The formed cylindrical holding seat 3 has an inner peripheral surface 3a whose inner diameter matches the outer diameter of the optical element L to hold the outer peripheral surface Lb of the optical element L mounted therein. A concave surface 6 is formed in the inner peripheral surface 3a so that the inner peripheral surface portion of the inner peripheral surface 3a corresponding to the outer peripheral edge Lc on the outer peripheral surface Lb on the side of the contact surface La of the optical element L does not come into contact with the outer peripheral surface. The circumferential ribs Lc are in contact. The concave surface 6 is recessed in a range including a portion facing the outer circumferential edge Lc and a side portion facing the holder 2.

When using the optical element holder 1 of this structure to grind or polish the optical element L, the element L is contained in the optical element holder 1 so that the inner peripheral surface 3a of the cylindrical holding seat 3 clamps the outer peripheral surface of the element Lb, while the contact surface La of the element is in contact with the elastic layer 4 . Note that a gap 7 of about 0.1-0.2 mm is formed between the inner peripheral surface 3a of the holding seat 3 and the outer peripheral surface Lb of the optical element L. As shown in FIG.

The optical element holder 1 holding the optical element L is placed on the processing machine, and the optical element L is brought into contact with a processing tool (not shown), such as a polishing plate having a radius of curvature to be processed, and placed on the clamping member The support on the support holder 5 of 2 (not shown; a rod-shaped member that can cooperate with the support holder 5) supports the optical element. Then, a load is applied to the optical element holder 1 . When the processing tool is driven to rotate around its central axis and the support member swings at the same time, under the rotation of the processing tool and the guidance of the support member, the optical element holder 1 and the optical element held by it have a curvature radius to be processed along the processing tool The processing surface rotates and arc swings. The combined motion of rotation and oscillation described above grinds or polishes the optical element.

When the optical element L is ground or polished as described above, resistance is generated due to the frictional force acting on the processing surface of the processing tool. Therefore, a rotational difference occurs due to follow-up rotation of the optical element L or variation in sliding between the contact portion of the optical element holder 1 and the optical element L during rotation of the optical element L. This rotational difference causes wear. Under the action of the swinging motion, the optical element L moves to one side of the optical element holder 1 . This swing cycle-dependent movement or the like produces excessive repeated impacts on the outer peripheral surface Lb of the optical element L. As shown in FIG. However, in this embodiment, since the optical element holder 1 has the concave surface 6, the outer peripheral edge Lc on the outer peripheral surface Lb on the contact surface La side of the optical element L does not contact the inner surface of the holding seat 3. The circumferential surfaces 3a are in contact. Therefore, the above-mentioned impact does not act on the fragile outer peripheral edge Lc, and such damage such as cracks or cuts in the optical element can be prevented.

(second embodiment)

A jig for grinding or polishing an optical element according to another embodiment of the present invention will be described with reference to FIG. 2 . Fig. 2 is a cross-sectional view of the optical element holder of the present embodiment.

The optical element holder 11 of the present embodiment shown in Fig. 2 is made of an integral holder-holder 12, which member is made of metal materials such as stainless steel, by making the holder part 12a and the cylindrical holder The part 12b is integrated to obtain this member. The supporting surface 12c of the holder part 12a is used to support the optical element L, and the inner peripheral surface 12d of the holder part 12b matches the outer diameter of the optical element L to clamp the optical element L contained therein The outer circumference of Lb. At the intersection of the supporting surface 12c and the inner peripheral surface 12d, on the outer peripheral surface Lb of the optical element L opposite to the outer peripheral edge Lc on the contact surface La side, at the above-mentioned position part of the integrated clamping seat-clamping member 12 The groove is obliquely opened to form the concave surface 16 . In FIG. 2, reference numeral 14 denotes an elastic layer, which is fixed by bonding on the bearing surface 12c of the integral clamping seat-clamping member 12, so as to be pressed against the contact surface La of the optical element L; Reference numeral 15 denotes a support seat formed in the central portion of the surface of the integral clamp seat-clamp 12, opposite to the support surface 12c.

When utilizing the optical element holder 11 of the above-mentioned structure to grind or polish the optical element L, since the concave surface 16 is obliquely recessed, even if too many repeated impacts act on the outer peripheral surface Lb of the optical element L, the outer circumference of the optical element L The rib Lc is also not pressed against the inner peripheral surface 12d of the holding seat portion 12b. Therefore, it is possible to avoid occurrence of such damages such as cracks or cuts in the outer peripheral edge Lc of the optical element L.

As described above, the function of the optical element holder 11 of this embodiment is similar to that of the first embodiment, whereby it is possible to obtain the same functions and effects as those of the first embodiment. The optical element holder 11 of the present embodiment is constituted by an integral holder-holder 12, which is made of a metal material such as stainless steel, and can be made by integrating the holder part 12a and the holder part 12b Get the widget. In this way, the wear resistance of the inner peripheral surface 12d of the holding seat portion 12b relative to the outer peripheral surface Lb of the optical element L which is in frictional contact can be improved, and it is possible to adapt to the limitations and limitations according to the processing machine and the size, shape, and the like of the optical element. The need to simplify the specification of optics fixtures.

Figure 3 shows an optics holder 21 for accommodating convex optics. The structure of this jig 21 is the same as that of the optical element jig 1 shown in FIG. 1 except that the supporting surface 22a of the jig 22 is concave.

Similarly, Figure 4 shows an optics holder 31 that accommodates a convex optic. The structure of this jig 31 is the same as that of the optical element jig 11 shown in FIG. 2 except that the supporting surface 32c of the jig 32 is concave.

Here's how to determine the dimensions of your optics holder.

Figure 5 shows an optical element L holder with a convex holder 2, and Figure 6 shows an optical element holder with a concave holder.

Referring to Figures 5 and 6, the concave interval X is determined by the height of the outer circumference of the lens to be processed according to the following formula:

X＝(a-b)+m′+c (1)

where a, b, c and m' are expressed by:

a=e×K

b=e×L

c=t×N

m'=m+Δh-Δh' (convex clamp)

m'=m+Δh'-Δh (concave clamp)

The meanings of the symbols used in the above relation are as follows:

a: The length of the portion of the clamping seat opposite to the outer circumference of the lens to be processed (clamping position)

b: The length of the part where the holder is in contact with the outer circumference of the lens to be processed

c: The length of the concave portion of the clamp seat opposite to the outer circumference of the clamp

e: the height of the outer circumference of the lens to be processed

t: Height of the outer peripheral portion of the clamp

K: Coefficient, expressing the ratio of the length of the portion of the holder opposite to the outer circumference of the lens to be processed to the height of the outer circumference of the lens to be processed

L: Coefficient, representing the ratio of the length of the part where the holder is in contact with the outer circumference of the lens to be processed to the height of the outer circumference of the lens to be processed

N: coefficient, indicating the ratio of the length of the concave portion of the clamping seat opposite the outer circumference of the clamp to the height of the outer circumference of the clamp

m: thickness of elastic layer 4

m': Thickness of the elastic layer portion corresponding to the outer peripheral portion of the holder Δh: Height difference between the central portion and the outer peripheral portion of the bearing surface of the support Δh': Elastic layer bonded to the holder The difference in height between the central part and the outer peripheral part of the

The relationship between the concave surface distance and the height of the outer peripheral portion of the lens to be processed will be described by citing the holder and the holder as two separate parts.

From the viewpoint of processing stability, the position a of the holding seat where the outer peripheral portion of the lens to be processed is clamped is preferably as low as possible (closer to the processing surface) relative to the processing surface. However, the position a is limited by the radius of curvature and shape to be machined, eg convex or concave. Therefore, when determining the clamping position a, according to the shape of the lens to be processed, the clamping position a is set to be 0.9-0.7 times the height e of the outer circumference of the lens to be processed. This ratio is set as coefficient K. The factor K determines the clamping position a.

The purpose of the length b of the portion of the clamping seat in contact with the outer circumference of the lens to be processed is to reduce the impact caused by movement during processing. Therefore, the determined length b is not longer than necessary, but also not particularly short, since wear resistance and the like must be maintained to a certain extent. For example, depending on the shape of the lens to be processed, some lenses have a low outer peripheral portion, and constraints must also be considered. Therefore, when determining the length b of the portion of the clamping seat in contact with the outer circumference of the lens to be processed, the length b is set to be 0.4-0.3 times the height e of the outer circumference of the lens to be processed according to the shape of the lens to be processed. This ratio is set as the coefficient L. The coefficient L determines the length b of the part where the clamping seat is in contact with the outer circumference of the lens to be processed.

Now, the length c of the concave portion of the holding seat opposed to the outer peripheral portion of the holding member will be described. When the load necessary for processing is applied to the optical element holder, even if the elastic layer is pressed by the load (the elastic layer is bonded to the supporting surface of the holder to accept the lens to be processed on the contact surface side thereof), the specific The concave surface of the lens must also ensure that the outer peripheral edge of the lens to be processed will not touch the holder. Furthermore, the holder itself must have a sufficient mounting portion so that it can be securely mounted to the holder. For the above reasons, when determining the length c of the concave surface portion of the holding seat opposite to the outer circumferential portion of the holding member, the length c is uniformly set to be 0.3 times the height of the outer circumferential portion of the holding member. This ratio is set as the coefficient N. The coefficient N determines the length c of the concave portion of the holding seat opposite to the outer peripheral portion of the holding member.

The thickness m' of the portion of the elastic layer bonded to the holding member corresponding to the outer peripheral portion of the holding member will be explained below. Since the elastic layer is bonded to the holding member, according to the radius of curvature of the holding member (the shape of the holding member is irrelevant), the thickness m′ and The thickness m of the elastic layer in a natural state satisfies m≤m'. Therefore, the margin obtained by subtracting the height difference Δh' from the total height which is the sum of the thickness m and the height difference Δh is equal to the thickness m', which can be obtained by the radius of curvature of the contact surface of the elastic layer bonded to the holding member. The above margin is obtained, wherein the thickness m is the thickness of the elastic layer in the natural state, the height difference Δh is the height difference between the central portion and the outer peripheral portion of the bearing surface of the clamping member, and the height difference Δh′ is the central portion of the contact surface The height difference between the outer peripheral portion and the thickness m′ is the thickness in the vertical direction of the portion of the elastic layer corresponding to the outer peripheral portion of the holding member. The above explanation applies when the clip is convex. If the clamp is concave, reverse Δh and Δh'.

Therefore, according to the relationship (1), the concave distance X can be obtained from the height (clamping position) a, length b, length c and thickness m', where a is the distance between the clamping seat and the outer circumference of the lens to be processed. The length of the part, b is the length of the part where the holder is in contact with the outer circumference of the lens to be processed, c is the length of the concave part of the holder and the outer circumference of the holder, and m' is the length of the part that is in contact with the holder. The outer circumference portion corresponds to the thickness of the elastic layer portion.

Similarly, as shown in the second embodiment, the concave surface obtained by obliquely making grooves on the part of the integral clamping seat-clamping member opposite to the outer circumferential edge of the lens to be processed is separated from the above-mentioned The same method is used to calculate the concave surface distance of the optical element fixture composed of the clamping piece and the clamping seat.

As described above, according to the above embodiment, in a jig for a separate optical element such as a lens (the jig is used when grinding or polishing an optical element), on the inner peripheral surface of the jig opposite to the fragile outer peripheral edge of the optical element A concave surface is formed in the part so that the jig does not press against the outer peripheral edge of the optical element. With this simple structure, even if repeated shocks are caused by abrasion or behavior, machining or the like caused by slight backlash between the optic and the optic holder, such shock will not damage the outer peripheral edge of the optic. This has the negative effect that no damages like cracks or cuts can form in the outer peripheral edge of the optical element. Therefore, grinding or polishing of optical elements such as lenses can be performed stably.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, the following claims are drafted to apprise the public of the scope of the invention.

Claims (5)

1. A clamp for optical element grinding or polishing, which includes a clamping piece and a cylindrical clamping seat, the clamping piece has a supporting surface, and the supporting surface supports the object to be ground or polished by an elastic layer The contact surface of the optical element; the cylindrical clamping seat is installed around the clamping piece, and has an inner peripheral surface matched with the outer diameter of the optical element to clamp the outer peripheral surface of the optical element, It is characterized in that a concave surface is formed on a part of the inner peripheral surface of the clamping seat, and this part is on the side of the contact surface of the optical element and is opposite to the outer peripheral edge of the outer peripheral surface of the optical element. 2. The clamp according to claim 1, wherein the clamping member and the clamping seat are integrally formed. 3. The jig according to claim 1 or 2, characterized in that the shape of the concave surface is obtained by making a groove in a part of the inner peripheral surface of the holding seat opposite to the outer peripheral surface of the optical element. 4. The fixture according to claim 1 or 2, characterized in that the concave surface is obtained by obliquely opening a groove on a part of the inner peripheral surface of the holding seat opposite to the outer peripheral edge of the optical element. shape. 5. A jig for grinding or polishing an optical element, wherein the grinding or polishing tool is placed above the surface of the optical element to be processed, and the optical element is clamped by an optical element holder through an elastic member on the side of the non-processing surface of the optical element , It is characterized in that a holding seat for stabilizing the outer peripheral surface of the optical element is provided in the optical element holding member, a concave surface is formed in the optical element holding seat opposite to one end of the outer peripheral portion of the optical element, and in A gap is formed between the optical element holding seat and the outer peripheral surface of the optical element.

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