JP2010173049A - Grinding machine, carrier for grinding machine, and grinding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding machine efficiently grinding an end surface of a columnar workpiece into a spherical shape even with a small radius of curvature; a carrier for the grinding machine; and a grinding method. <P>SOLUTION: In the carrier for the grinding machine, the columnar workpiece 30 is inserted into a through-hole having a narrowed portion 122 therein. By moving the carrier for the grinding machine with respect to upper and lower surface plates, one of which is driven to rotate with respect to the other, while allowing the carrier for the grinding machine to rotate on its axis between these surface plates, the workpiece 30 is irregularly swung with the narrowed portion 122 as a supporting point. By this swing, the end surface of the workpiece 30 can be uniformly rubbed against the surface plates, thereby grinding the end surface into the spherical surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polishing machine for polishing spherical surfaces of optical elements and the like, a carrier for a polishing machine, and a polishing method using them.

  Conventionally, an Oscar type polishing machine is known as a polishing machine for spherically polishing an optical element such as a lens. FIG. 13 shows a schematic configuration of a main part of the Oscar type polishing machine 50. The Oscar-type polishing machine 50 includes a fixed plate 52 on which a work 51 such as a lens is fixed on the upper surface, and a polishing plate 53 arranged to face the fixed plate 52. The fixed plate 52 rotates around a rotating shaft 521 protruding downward from the center of the lower surface. The lower surface of the polishing dish 53 has a predetermined curvature, and a polishing pad 54 is attached to the surface. A swing arm 55 whose tip is swung in a horizontal plane (a plane perpendicular to the paper surface) is disposed above the polishing dish 53, and a bar material called a kanzashi 56 is suspended from the tip. The polishing dish 53 is supported at the lower end of the canker 56 so as to be tiltable.

  When performing spherical polishing using such an Oscar-type polishing machine 50, the work 51 is fixed to the fixing plate 52 with wax or the like, and then fixed while supplying an abrasive between the work 51 and the polishing pad 54. The workpiece 51 is rotated by the rotation of the plate 52 and the polishing plate 53 is reciprocated by the swing of the swing arm 55. Thereby, the entire upper surface of the workpiece 51 is polished into a spherical surface.

  Although FIG. 13 shows an example in which one workpiece 51 is fixed to the fixed plate 52, a plurality of workpieces 58 such as small lenses may be fixed to the fixed plate 57 as shown in FIG. Thereby, a plurality of workpieces 58 can be spherically polished at a time.

Other than the Oscar type polishing machine, a polishing machine for spherical polishing has been proposed. The polishing machine described in Patent Document 1 places a spherical work on a rotatable disc-shaped grindstone, rotates the grindstone while covering the work with a holder from above, and rolls the work to perform spherical polishing. Do.
In the polishing machine described in Patent Document 2, a carrier having a plurality of through holes is arranged between upper and lower surface plates, and a spherical work larger than the height of the hole is put in each through hole. The entire surface of the workpiece is polished by rotating the upper and lower surface plates in opposite directions and moving the carrier in a planetary motion while holding them with the upper and lower surface plates.

JP-A-6-31608 JP 2002-326154 A

  In recent years, the end face of a semiconductor-pumped solid-state laser element has been given the function of a mirror of a laser resonator. For example, laser resonance occurs between one end face of a laser element and a concave mirror disposed on the other end face side. It has been proposed to form a vessel. Furthermore, with the aim of further miniaturization, high efficiency, and low price, it is called a monolithic laser element in which both ends of a laser element or a laser element and a nonlinear optical element are subjected to spherical processing and a laser resonator is formed by these spherical surfaces. Laser elements have also been proposed. Usually, the monolithic laser element has a columnar shape with a length of about 1 to 2 mm, and the axis of the column coincides with the crystal axis of the laser crystal.

It is not easy for a conventional polishing machine to efficiently spherically polish the end face of such a small laser element with a small radius of curvature (for example, a radius of curvature of several millimeters). In order to polish the workpiece end face with a small radius of curvature in an Oscar type polishing machine, a polishing dish having a lower surface corresponding to the curvature radius must be used. With such a polishing dish, a workpiece that can be polished at one time is used. The number is limited.
In an Oscar-type polishing machine, a problem also arises when a workpiece is fixed to a fixed plate with wax. When fixing a columnar laser element in a standing position with wax, it is not easy to accurately fix a large number of laser elements so that their crystal axes are in a predetermined direction. Further, when the workpiece is fixed in a state where it floats from the fixed plate in the wax, an error occurs in the length of the workpiece after polishing.

  The polishing machines described in Patent Documents 1 and 2 are used for spherical polishing of the entire surface of a spherical workpiece, and cannot be used for applications in which the end surfaces of the spherical workpiece are polished while controlling the direction of the crystal axis as in a laser element. .

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a polishing machine, a polishing machine carrier capable of efficiently spherically polishing the end surface of a columnar workpiece with a small radius of curvature. It is to provide a polishing method.

A carrier for a polishing machine according to the present invention made to solve the above-mentioned problems,
Up-down adjustment that has one or a plurality of through holes for inserting columnar workpieces, and is driven so that one of them rotates relative to the other with the opposing surfaces arranged parallel to each other. A polishing machine carrier that moves relative to the surface plate while rotating between the plates,
Inside the through-hole, there is a narrowed portion with an inner diameter so that a predetermined gap is formed between the inserted workpiece and the side surface of the inserted workpiece, and the workpiece inserted into the through-hole during the movement is It is characterized in that the end surface of the workpiece is subjected to spherical polishing by swinging around the portion as a fulcrum.

Further, a polishing machine according to the present invention made to solve the above problems is
a) Upper and lower surface plates that are arranged facing each other and whose opposing surfaces are parallel to each other;
b) a surface plate driving mechanism for driving the upper and lower surface plates so that one rotates relative to the other;
c) A narrowed portion having an inner diameter so as to have one or a plurality of through holes for inserting a columnar workpiece, and a predetermined gap is formed between the through hole and the side surface of the inserted workpiece. A carrier for a polishing machine having
d) a carrier driving mechanism for moving the polishing machine carrier relative to the surface plate while rotating between the upper and lower surface plates;
And the workpiece inserted into the through-hole during the movement of the carrier for the polishing machine swings around the narrowed portion as a fulcrum, thereby polishing the end surface of the workpiece. .

Furthermore, the polishing method according to the present invention made to solve the above problems is
A columnar workpiece is inserted into one or more through-holes between the upper and lower surface plates that are arranged to face each other and are driven so that one of them faces the other in parallel. A polishing machine carrier, wherein the surface plate is rotated while rotating the polishing machine carrier having a narrowed portion with an inner diameter such that a predetermined gap is formed between the through hole and the side surface of the workpiece. The end surface of the workpiece is spherically polished by moving the workpiece with respect to the narrowed portion and using the narrow portion as a fulcrum.

  According to the polishing machine, the carrier for the polishing machine, and the polishing method according to the present invention, the carrier for the polishing machine in which the columnar workpiece is inserted into the through hole having the narrowed portion inside is rotated between the upper and lower surface plates that rotate with each other. However, by performing a complicated movement with respect to the surface plate, the workpiece inserted into the through hole swings irregularly with the narrow portion as a fulcrum. By this swinging, the end surface of the work is evenly rubbed against the surface plate, and the end surface is polished into a substantially spherical surface.

The radius of curvature of the workpiece end surface to be polished is substantially determined by the distance from the narrowed portion to the workpiece end surface. Therefore, by reducing the distance, end face polishing with a small radius of curvature is facilitated. Therefore, if a large number of through holes are provided in one carrier for a polishing machine and a short work is inserted into each through hole, the end face of each work can be polished at a time with a small curvature radius.
The workpiece does not need to be fixed with wax or the like, and only needs to be inserted into the through hole. Since the end surface is spherically polished around the main axis of the workpiece, it is not necessary to use a nerve to set the workpiece, and can be easily set in a short time. In addition, since the length of the workpiece after polishing is determined by the distance between the upper and lower surface plates, the length of each workpiece is substantially constant even when a large number of workpieces are polished at the same time as described above.

It is a figure explaining the carrier for polishers concerning Example 1 of the present invention, (a) is a top view and (b) is an AA arrow sectional view of (a). The figure which shows an example of the formation method of the through-hole which has a constriction part. 1 is an exploded perspective view of a carrier for a polishing machine according to Embodiment 1. FIG. It is a figure explaining the carrier for grinding machines concerning Example 1, (a) is a perspective view and (b) is a section perspective view which cut out the neighborhood of a penetration hole. It is a figure explaining the state which inserted the workpiece | work in the through-hole, (a) is a longitudinal cross-sectional view when a workpiece | work stands upright, (b) is a longitudinal cross-sectional view when a workpiece | work inclines. A side view of a work when an upright work is inclined. The longitudinal cross-sectional view which shows a mode that a workpiece | work rock | fluctuates within a through-hole. FIG. 3 is a perspective view illustrating a state where the upper surface plate is lifted in the polishing machine according to the first embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the grinding | polishing method based on Example 1, (a) is a perspective view of a laser crystal substrate, (b) is a perspective view of the cut | disconnected laser crystal substrate, (c) is a perspective view of the cut-out workpiece | work. It is. It is a figure explaining the rocking | fluctuation of the workpiece | work within a through-hole, (a) is a longitudinal cross-sectional view when a workpiece | work stands upright, (b) is a longitudinal cross-sectional view when a workpiece | work is rocking | fluctuating, c) is a longitudinal sectional view after polishing. It is a figure explaining the grinding | polishing method which concerns on Example 2, (a) is a perspective view of the laser crystal substrate before bonding, (b) is a perspective view of the cut | disconnected laser crystal substrate, (c) is before grinding | polishing. The side view of a workpiece | work, (d) is a side view of the workpiece | work after grinding | polishing, (e) is a side view of the laser element formed by isolate | separating a workpiece | work. It is a figure explaining the modification of the rocking | fluctuation of the workpiece | work within a through-hole, (a) is a longitudinal cross-sectional view when the workpiece | work is rock | fluctuating, (b) is a longitudinal cross-sectional view after grinding | polishing. The figure which shows schematic structure of the principal part of an Oscar type polisher. The figure which shows schematic structure of the principal part of an Oscar type polisher.

  Embodiments of a polishing machine, a carrier for a polishing machine, and a polishing method according to the present invention will be described below with reference to the drawings.

  FIG. 1 shows a plan view (a) and a sectional view (b) of a carrier 10 for a polishing machine according to a first embodiment of the present invention. The carrier 10 for a polishing machine is a disc having a gear 11 on the outer periphery, and has a through-hole 12 for inserting a columnar workpiece. The number of through holes 12 is arbitrary, but is 12 here. Inside the through-hole 12, a narrowed portion 122 having an inner diameter that is narrower than the opening 121 and that forms a predetermined gap with the side surface of the workpiece is provided. In this embodiment, the narrowed portion 122 is formed in the center of the through hole 12 in the depth direction.

  FIG. 2 shows an example of a method for forming the through hole 12 having the narrowed portion 122. In this example, the through-hole 12 having the narrowed portion 122 is produced by processing one disk. First, a through hole 12A having an inner diameter coinciding with the narrowed portion 122 is formed in the disk 10A having a predetermined thickness by machining or the like (FIG. 2A), and then coincides with the opening 121 from both sides of the through hole 12A. A counterbore 12B having an inner diameter is processed (FIG. 2B). Thereby, the narrow portion 122 is formed between the bottom surfaces of the two spot facings 12B.

  The through-hole 12 having the narrowed portion 122 can also be formed using three disks as shown in FIG. In this method, an intermediate disk 14 having an inner diameter opening corresponding to the constriction 122 by machining or etching, and two outer disks 13 having an inner diameter opening corresponding to the opening 121 are prepared. The outer disk 13 is fixed to both surfaces of the intermediate disk 14 by bonding or the like so that the centers of the openings of the intermediate disk 14 and the outer disk 13 coincide. Thereby, a carrier 10 for a polishing machine having a three-layer structure as shown in FIG. 4 is obtained. Since this method does not require precise machining, it is suitable when the carrier for the polishing machine is thin.

The material of the outer disk 13 and the intermediate disk 14 may be determined in consideration of mechanical strength, wear resistance, ease of processing, etc. For example, a metal such as stainless steel or a plastic such as epoxy / vinyl chloride is used. Can do.
In this embodiment, the outer peripheral gear is formed on both the outer disk 13 and the intermediate disk 14 so that the surface area of the side surface of the gear 11 is made as wide as possible, and the mechanical strength and wear resistance of the gear are increased. However, the processing cost may be suppressed by forming the gear only on a part of the disks.

The height and inner diameter of the narrowed portion 122 are set as follows. FIG. 5 shows a longitudinal sectional view when the work 30 is inserted into the through hole 12. Here, the workpiece 30 is a cylinder having a length L and a diameter D, and the narrow portion 122 is a height t and an inner diameter (D + 2d). d is the size of the gap formed between the narrowed portion 122 and the side surface of the workpiece 30 when the workpiece 30 is arranged at the center of the opening of the narrowed portion 122 as shown in FIG.
FIG. 6 shows a side view of the workpiece 30 when the upright workpiece 30 is inclined with a certain point at the edge of the lower end surface as a fulcrum P. FIG. When the workpiece 30 has a center of gravity O on the vertical line passing through the fulcrum P (FIG. 6B), the work 30 tries to return to an upright state if the inclination is smaller than that (FIG. 6A). If the inclination is larger than that, it tends to fall sideways (FIG. 6C). The work 30 is given a frictional force larger than the gravitational force (partial force) from the upper and lower surface plates. In order to polish the entire end face more uniformly, the work 30 is in the state shown in FIG. It is desirable to be. There are two cases where the maximum inclination of the work 30 is the case where the upper and lower ends of the work 30 are restricted by the opening and the case where the center part of the work 30 is restricted by the narrowed portion 122. In any case, the maximum inclination of the workpiece is shown in FIG. 6 by appropriately determining the length and inner diameter of the opening 121 or the height and inner diameter of the narrowed portion 122 according to the length L and diameter D of the workpiece 30. It is desirable that (b) be satisfied. In the case of FIG. 6B, the inclination angle θ is calculated as follows.
θ = tan ⁻¹ (D / L)
When the central portion of the workpiece 30 is regulated by the narrowed portion 122, the relationship between the maximum inclination angle θ, the height t of the narrowed portion 122, and the gap d can be expressed as follows.
t = 2d / tanθ− (D / tanθ) · ((1 / cosθ) −1)
d = (t / 2) · tan θ + (D / 2) · ((1 / cos θ) −1)
For example, if the length L of the workpiece 30 is 2 mm and the diameter D is 1 mm, the clearance d is first set to 0.15 mm (2d = 0.3 mm) in consideration of the machining accuracy of the workpiece 30 and the narrowed portion 122. Then, the height t of the constriction 122 is determined to be 0.36 mm. Similarly, when the gap d is 0.15 mm, the height t of the constricted portion 122 is 0.74 mm when the length L of the workpiece 30 is 3 mm and the diameter D is 1 mm, the length L of the workpiece 30 is 5 mm, and the diameter D is If it is 2mm, it becomes 0.36mm.

  The maximum inclination of the work 30 may be regulated by the opening 121 as shown in FIG. Thereby, the force applied to the edge of the narrowed portion 122 during polishing is reduced, and early wear of the narrowed portion 122 is prevented.

FIG. 8 shows a perspective view of the polishing machine 20 in which the polishing machine carrier 10 is disposed between the upper surface plate 21 and the lower surface plate 22. This figure shows a state where the upper surface plate 21 is lifted. The upper surface plate 21 and the lower surface plate 22 are circular plates having a circular opening at the center and face each other. On the upper surface of the upper surface plate 21, circumferential and radial flow paths 211 for pouring the abrasive into the opposing surface (polishing surface) of each surface plate, and two hooks extending in the center direction from the edge of the central opening 212 is provided.
The carrier 10 for polishing machine is placed on the lower surface plate 22. In FIG. 8, three polishing machine carriers 10 are shown as representatives, but in reality, the other polishing machine carriers 10 are also arranged rotationally symmetrically on the lower surface plate 22, and the load from the upper surface plate 21 is subjected to each polishing. It is desirable that the workpiece 30 in the machine carrier 10 be applied without any bias.

A ring-shaped internal gear 23 having a gear on the inner side is disposed on the outer peripheral side of the upper and lower surface plates, and a ring-shaped external gear 24 having a gear on the outer side is disposed on the center side of the upper and lower surface plates. These gears mesh with the gear 11 of the carrier 10 for the polishing machine.
On the center side of the external gear 24, an upper surface plate drive unit 25 provided with a notch 251 for engaging with the hook 212 at the edge of the upper surface is arranged. The upper surface plate 21 is rotated by the upper surface plate driving unit 25. The lower surface plate 22, the internal gear 23, and the external gear 24 are also rotationally driven by a drive mechanism such as a motor.

Hereinafter, a method for polishing a laser element using the carrier 10 for polishing machine and the polishing machine 20 will be described. First, a laser crystal substrate 31 (FIG. 9A) cut out in a plane perpendicular to the crystal axis direction is cut into a lattice shape with a dicing saw or the like (FIG. 9B), and a number of columnar laser elements (work 30) are cut. ). In general, the workpiece 30 is preferably a columnar shape, but may be a prism as shown in FIG. 9C as long as the constricted portion 122 is circular. Conversely, if the workpiece 30 is cylindrical, the constricted portion 122 may be polygonal.
Instead of the laser crystal substrate 31, a bonding plate of a laser crystal substrate and a nonlinear optical crystal substrate may be used, and a monolithic laser element in which the laser crystal and the nonlinear optical crystal are bonded may be cut out from the bonding plate.

  Next, the cut workpiece 30 is inserted into the through hole 12 of the polishing machine carrier 10 on the polishing machine 20 shown in FIG. 8, and the upper surface plate 21 is placed thereon. And while supplying an abrasive | polishing agent between the surface plates from the flow path 211 of the upper surface plate 21, the upper surface plate 21 and the lower surface plate 22 are rotationally driven in the mutually opposite direction in the state which made each opposing surface parallel. Further, the internal gear 23 and the external gear 24 are rotated at different rotational speeds so that the polishing machine carrier 10 revolves (planetary motion) while rotating between the surface plates.

The state of the workpiece 30 in the through hole 12 at this time is shown in FIG. The workpiece 30 (FIG. 10A) inserted into the through-hole 12 swings irregularly around the narrowed portion 122 as a fulcrum in the through-hole 12 by the rotation of the upper and lower surface plate and the polishing machine carrier 10 described above. (FIG. 10 (b)). Due to this swinging, both end surfaces of the work 30 uniformly rub against the upper and lower surface plates, and the end surfaces are polished into spherical surfaces (FIG. 10C).
At this time, the radius of curvature of the polished work end face substantially matches the distance from the narrowed portion 122 to the end face. In this embodiment, the narrowed portion 122 is provided in the center of the through hole 12 in the depth direction, and the carrier 10 is disposed in the center between the upper and lower surface plates, so that the curvature radii of both end surfaces are the same. .

  FIG. 11 is a view for explaining a polishing method according to the second embodiment of the present invention. In the polishing method according to the present embodiment, the workpiece 40 produced as follows is polished using the same carrier 10 for polishing machine and the polishing machine 20 as in the first embodiment.

  First, two laser crystal substrates 41 (FIG. 11A) are bonded together with wax or the like and integrated. The integrated joining plate 42 is cut into a lattice shape on a surface intersecting the joining surface using a dicing saw or the like (FIG. 11B), and the columnar workpiece 40 having the joining portion 44 is cut out (FIG. 11). (C)). The workpiece 40 is set in the polishing machine 20 in the same manner as in the first embodiment, and both end surfaces thereof are polished to a spherical surface (FIG. 11 (d)).

  After the polishing is completed, the workpiece 40 is taken out from the carrier 10 for the polishing machine and separated at the joint portion 44 of the workpiece 40 (FIG. 11E). As a result, it is possible to obtain the laser element 43, which is an object to be polished whose one surface is spherically polished.

  The present invention is not limited to the above-described embodiments, and appropriate modifications are allowed within the scope of the gist of the present invention. For example, in order to polish both end faces of the workpiece with different curvatures, the narrowed portion 122 may be provided at a position shifted from the center in the depth direction of the through hole 12 as shown in FIG. Since the radius of curvature of the end face of the work 30 is determined by the distance from the narrowed portion 122 to the end face, in this example, the radius of curvature is large on one end face and small on the other end face (FIG. 12B). Further, by combining this method with the method of bonding two substrates shown in Example 2, two types of objects to be polished having different curvature radii on one end face can be produced by one polishing.

  A dummy member having a predetermined length may be fixed to the object to be polished, and the end surface of the columnar workpiece made of the object to be polished and the dummy member may be spherically polished. Thus, the radius of curvature of one surface of the object to be polished can be adjusted by the length of the dummy member. In addition, when the object to be polished is difficult to swing in the through hole, for example, it is flat, a dummy member having a predetermined length is fixed to the object to be polished, and a workpiece made of the object to be polished and the dummy member is fixed. If it is swung in the through hole, one surface of the object to be polished which is difficult to be spherically polished can be easily spherically polished.

  The movement of the carrier for the polishing machine between the upper and lower surface plates is not limited as long as the workpiece can be rocked irregularly in the through hole. In addition to the planetary motion described above, for example, while rotating, It is also possible to make it swing irregularly.

  If the thickness of the carrier for the polishing machine, the diameter of the through hole, etc. are appropriately selected according to the size of the workpiece, not only a small workpiece such as a laser element but also a relatively large workpiece can be polished.

DESCRIPTION OF SYMBOLS 10 ... Polishing machine carrier 11 ... Gear 12 ... Through-hole 121 ... Opening part 122 ... Constriction part 13 ... Outer disk 14 ... Intermediate disk 15 ... Outer disk 20 ... Polishing machine 21 ... Upper surface plate 211 ... Channel 212 ... Hook 22 ... Lower surface plate 23 ... Internal gear 24 ... External gear 25 ... Upper surface plate drive unit 251 ... Incisions 30, 40, 51, 58 ... Workpieces 31, 41 ... Laser crystal substrate 42 ... Junction plate 43 ... Laser element 44 ... Junction 50 ... Oscar type polishing machine 52 ... fixed plate 521 ... rotating shaft 53 ... polishing plate 54 ... polishing pad 55 ... oscillating arm 56 ... mountain 57 ... fixed plate

Claims (7)

Up-down adjustment that has one or a plurality of through holes for inserting columnar workpieces, and is driven so that one of them rotates relative to the other with the opposing surfaces arranged parallel to each other. A polishing machine carrier that moves relative to the surface plate while rotating between the plates,
Inside the through-hole, there is a narrowed portion with an inner diameter so that a predetermined gap is formed between the inserted workpiece and the side surface of the inserted workpiece, and the workpiece inserted into the through-hole during the movement is A carrier for a polishing machine, characterized in that the end surface of the workpiece is subjected to spherical polishing by swinging about a portion as a fulcrum. The polishing machine carrier is
a) an intermediate disc having the constriction,
b) an outer disk fixed to both surfaces of the intermediate disk and having an opening with an inner diameter larger than that of the constriction at a position corresponding to the constriction;
The carrier for a polishing machine according to claim 1, comprising:   3. The carrier for a polishing machine according to claim 1, wherein the narrowed portion is provided at the center in the depth direction of the through-hole in order to polish both end surfaces of the columnar workpiece with the same curvature. .   The said narrowing part is provided in the position shifted | deviated from the center of the depth direction of the said through-hole in order to grind | polish the both end surfaces of a columnar workpiece | work with a different curvature, The Claim 1 or 2 characterized by the above-mentioned. Carrier for polishing machine. a) Upper and lower surface plates that are arranged facing each other and whose opposing surfaces are parallel to each other;
b) a surface plate driving mechanism for driving the upper and lower surface plates so that one rotates relative to the other;
c) A narrowed portion having an inner diameter so as to have one or a plurality of through holes for inserting a columnar workpiece, and a predetermined gap is formed between the through hole and the side surface of the inserted workpiece. A carrier for a polishing machine having
d) a carrier driving mechanism for moving the polishing machine carrier relative to the surface plate while rotating between the upper and lower surface plates;
And the workpiece inserted into the through-hole swings around the narrowed portion during the movement of the polishing machine carrier, whereby the end surface of the workpiece is spherically polished. Polishing machine.   A carrier for a polishing machine in which a columnar workpiece is inserted into one or a plurality of through holes, and a narrowed portion having an inner diameter such that a predetermined gap is formed between the through holes and a side surface of the workpiece. A carrier for a polishing machine having the surface of the polishing machine is rotated while rotating between upper and lower surface plates which are arranged to face each other and are rotated so that one of them is rotated with respect to the other. A polishing method comprising: spherically polishing an end surface of a workpiece by moving the workpiece with respect to a disc and swinging the workpiece with the narrow portion as a fulcrum.   A columnar workpiece having a bonding portion, which is produced by cutting a bonding plate bonded with a plurality of substrates at a plane intersecting the bonding surface, is inserted into the through hole, and the spherical polishing is performed on the workpiece. 7. The polishing method according to claim 6, wherein after the workpiece is separated at the joint portion, the object to be polished whose surface is spherically polished is formed.

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