JP2011235424A - Dish-shaped diamond grindstone and method for grinding spherical lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a dish-shaped diamond grindstone by which the prescribed amount of a spherical lens can be ground in a short time and the spherical lens can be ground to have prescribed surface roughness so that the stock removal rate at the next grinding step can be decreased.SOLUTION: The dish-shaped diamond grindstone 60 for grinding the spherical lens includes: a tool dish body 62 having the spherical surface 61 complementary to the spherical surface of the spherical lens to be ground; and an abrasive material layer 63 which is layered on the spherical surface 61 and has fixed thickness. Mutual rubbing correction working is applied to diamond abrasive grains 65 projected from the surface 63a of the abrasive material layer 63, so that a difference ΔH between the maximum projection quantity H1 of the diamond abrasive grains 65 and the minimum projection quantity H2 thereof becomes equal to or smaller than a prescribed value. As a result, the surface accuracy of the cutting surface can be enhanced while making a cut blem, which is made on the ground surface by the dish-shaped diamond grindstone 60, smaller without decelerating a cutting speed of the dish-shaped diamond grindstone 60.

Description

  The present invention relates to a diamond dish type grindstone used for grinding an optical spherical lens used in a digital camera or the like, and a spherical lens grinding method using the diamond dish type grindstone.

  As a method for grinding an optical spherical lens, a method of creating a spherical surface using a dish-type grindstone having a spherical grinding surface is widely known. For example, the lens spherical surface is processed through three steps of a rough grinding step, a fine grinding step, and a polishing step. The required machining allowance for each step is generally 0.5 to 2 mm for rough grinding, 30 to 50 μm for fine grinding, and 10 to 20 μm for polishing. The surface roughness Rmax is 6 to 10 μm for rough grinding, 0.5 to 4 μm for fine grinding, and 0.01 to 0.02 μm for polishing. Further, the optimum particle diameter of the diamond dish type grindstone is selected according to the distribution of the processing time in each process. In particular, based on the surface roughness in the rough grinding process, which is the first grinding process, the processing time distribution in the subsequent process and the particle size of the diamond dish type grindstone are determined.

  In order to reduce the surface roughness, it is only necessary to reduce the cutting flaws caused by the diamond dish type grindstone. For this purpose, the abrasive grain size of diamond may be reduced. For example, in the lens grinding apparatus disclosed in Patent Literatures 1 and 2 by the applicant of the present application, when performing rough grinding of a lens material using a diamond dish type grindstone having a grain size of # 200 (JIS), the abrasive grain of # 200 Therefore, the depth of the cutting flaw is set to about 70 μm, and this 70 μm is used as a machining allowance in the next precision grinding step. If a diamond dish type grindstone having a finer grain size than # 200 is used, the machining allowance in the next precision grinding process can be reduced. For example, abrasive grains of # 1200 (average particle size 12 μm) or # 1500 (average particle size 10 μm) may be used. However, the cutting speed of the # 1200 and # 1500 abrasive grains is as slow as about 5 μm / second. For example, in order to roughly grind the lens material by 700 μm, a processing time of about 140 seconds is required.

  Thus, when the abrasive grain size of the diamond dish type grindstone is made fine, the processing time naturally becomes long. Therefore, conventionally, the fine grinding process is divided into two processes in consideration of the surface roughness, machining allowance, and processing time in the fine grinding process. In the first process, for example, 50 μm of grinding is performed using a metal bond grindstone as a diamond dish-type grindstone. In this way, fine grinding with a machining allowance of 70 μm and a surface roughness of 0.5 μm, for example, is realized.

  Here, in the grinding process of the spherical lens, if the surface roughness in the precision grinding process is sacrificed, the precision grinding can be performed in a single process, and the processing time can be shortened. However, because the surface roughness in the next process is determined based on the surface roughness in the previous process, if the surface roughness in the fine grinding process is sacrificed, the machining allowance in the polishing process, which is the next process, increases. Processing time will be significantly longer. Therefore, the overall machining time cannot be shortened.

  Therefore, the applicant of the present application has proposed a grinding method in which rough grinding conditions are set so that fine grinding can be performed in a single process in Patent Document 3. According to this method, it is possible to shorten the time for grinding the spherical lens and rationalize the process management.

JP 2003-340702 A JP 2007-253279 A JP 2007-253280 A

  The object of the present invention is to provide a diamond that can be ground with a predetermined surface roughness so that a predetermined amount of grinding can be performed in a short time compared to the prior art, and the machining allowance in the next grinding process can be reduced. The idea is to propose a dish-type grindstone.

  Another object of the present invention is to propose a grinding method of a spherical lens that can shorten the grinding time by using such a new diamond dish type grindstone.

In order to solve the above problems, the diamond dish type grindstone for spherical lens processing of the present invention,
It has a tool plate body having a spherical surface complementary to the lens spherical surface to be processed, and an abrasive layer of a certain thickness laminated on the spherical surface,
The abrasive layer is made of an abrasive in which diamond abrasive grains are dispersed and mixed in a bond material,
Many diamond abrasive grains protrude from the surface of the abrasive layer,
The diamond grindstone protruding from the surface of the abrasive layer is subjected to co-rubbing correction processing, and the difference between the maximum protrusion amount and the minimum protrusion amount of the diamond abrasive grains is a predetermined value or less. Yes.

  For example, by using a correction dish having a co-friction surface that is the same spherical surface as the lens spherical surface to be processed, by applying the co-friction correction process to the spherical abrasive surface of the diamond dish type grindstone, the maximum protrusion amount of the diamond abrasive grains The difference in the minimum protrusion amount can be reduced. Thereby, without reducing the cutting speed of the diamond dish type grindstone, it is possible to reduce the cutting flaws on the ground surface by the diamond dish type grindstone and increase the surface accuracy of the cutting surface.

  Here, it is desirable that the difference between the maximum protrusion amount and the minimum protrusion amount of the diamond abrasive grains is within a range of 1/3 to 1/6 of the particle diameter of the diamond abrasive grains.

  When used for rough grinding of a spherical lens, the average grain size of the diamond abrasive grains may be 149 to 37 μm (JIS general abrasive grain size: # 100 to # 400).

  Further, the abrasive layer is formed by adhering and fixing diamond pellets having a constant thickness at predetermined intervals to the spherical surface of the tool plate body, which is made of an abrasive material in which diamond abrasive grains are dispersed and mixed in a bond material. Can be formed.

  The diamond dish type grindstone of the present invention is suitable for use in grinding the spherical surface of a spherical lens.

The spherical lens grinding method according to the present invention comprises:
A rough grinding step of roughly creating a lens spherical surface by rough grinding the lens surface of the lens material to be processed using the diamond dish type grindstone,
A fine grinding process for finely grinding the created rough grinding lens spherical surface using a fine grinding tool plate;
A polishing step of polishing the lens spherical surface after fine grinding,
In the rough grinding process,
The diamond dish type grindstone is rotated about a rotation center line passing through the spherical center of the spherical surface, and the diamond dish type grindstone is drawn with a conical surface whose rotation center line is the vertex of the ball center. Sway the ball center,
While rotating the lens material in the same direction as the diamond dish type grindstone, press against the diamond dish type grindstone,
A spherical grinding process is performed on the lens material while feeding the lens material in this state.

  Here, if the average particle diameter of the diamond abrasive grains is 149 to 37 μm (JIS general abrasive grain diameter: # 100 to # 400), the machining allowance in the fine grinding step can be set to 20 μm or less. As a result, precise grinding can be performed as a single grinding process, grinding time can be shortened, and process management is simplified.

  In the diamond dish type grindstone of the present invention, the surface of the abrasive layer on which the diamond abrasive grains are dispersed and mixed is subjected to co-rubbing correction processing to reduce the difference between the maximum protrusion amount and the minimum protrusion amount of the diamond abrasive grains. . Thereby, without reducing the cutting speed of the diamond dish type grindstone, it is possible to reduce the cutting flaws on the ground surface by the diamond dish type grindstone and increase the surface accuracy of the cutting surface.

  Further, according to the spherical lens grinding method of the present invention, it is possible to perform rough grinding at a grinding speed similar to the conventional one using a diamond dish type grindstone having a grain size used for rough grinding, and at the same time, lens grinding. The surface accuracy of the surface can be increased compared to the conventional one. Therefore, since the machining allowance is small in the next precision grinding process, the precision grinding can be performed in a short time by a single grinding process using a diamond dish type grindstone having a small particle diameter. As a result, it is possible to efficiently perform spherical lens grinding including rough grinding, fine grinding, and polishing in a short time.

It is process drawing which shows the grinding process process of the spherical glass lens by this invention. It is a schematic block diagram which shows the ball center rocking | swiveling type grinding machine suitable for using for rough grinding. (A) is sectional drawing which shows the diamond plate type grindstone which is the resin bond grindstone for rough grinding, (b) is the partial expanded sectional view, (c) is the diamond plate before performing a co-rubbing correction process It is a partial expanded sectional view which shows a type | mold grindstone. (A)-(e) is explanatory drawing which shows an example of the manufacturing method of a diamond plate type grindstone.

  A spherical lens grinding method and a diamond dish type grindstone to which the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a process diagram showing a grinding method of an optical spherical lens of this example. As shown in this figure, the grinding method of the present example includes three steps of a rough grinding step ST1, a fine grinding step ST2, and a polishing step ST3. The rough grinding step (CG step) ST1 is a step of roughly creating a lens spherical surface by grinding a lens material to be processed using a diamond plate type grindstone (rough grinding tool plate). The fine grinding step ST2 is a step in which the created lens spherical surface is finely ground using a diamond plate-type grindstone having a particle diameter finer than that of the rough grinding tool pan, and is a single grinding step. The grinding machine to be used is not limited to the ball center swing type, and a grinder using a general cup type grindstone can be used. Moreover, a resin bond grindstone may be used as the diamond dish type grindstone. Next, the polishing step ST3 is a step of polishing the lens spherical surface after fine grinding. In this step, for example, the spherical surface is polished with a polishing liquid containing cerium oxide or the like using a urethane sheet.

(Rough grinding process)
In the rough grinding step ST1, a spherical surface is created on the lens material under the following conditions (1) to (3).
(1) The lens material is roughly ground using a ball center rocking type grinding device. As the ball center rocking grinding device, the one shown in FIG. 2 can be adopted.
(2) As a rough grinding tool plate, a diamond plate type grindstone having a particle size of # 100 to # 400 (JIS standard, average particle size: 149 to 37 μm) is used.
(3) The rotational speed of the rough grinding tool pan is 2500 rpm to 3500 rpm, for example 3000 rpm.

(Spherical rocking grinder)
The oscillating grinding device rotates a rough grinding tool plate having a spherical grinding surface around a rotation center line passing through the spherical center of the spherical surface, and the rotation center line has the sphere center at the top. The ball center is swung so as to draw a conical surface. Also, while rotating the lens material at the same speed in the same direction as the rough grinding tool pan, it is pressed against the grinding surface of the rough grinding tool pan that is rotating and pivoting, and in this state the lens material is fed out, The lens material is subjected to spherical grinding. Further, the rough grinding tool plate is supported by a spherical rocking body in a rotatable state, the outer peripheral surface of the spherical rocking member is a spherical surface, and the outer circumferential surface is centered on the spherical surface of the grinding surface of the rough grinding tool plate. The spherical rocking body is placed on a spherical supporting surface and compressed air is supplied between the outer peripheral surface and the supporting surface to float the spherical rocking body, and the spherical rocking body is rocked while maintaining the floating state. It is like that.

  When described in detail with reference to FIG. 2, the spherical rocking grinding apparatus 1 grinds the lens holder 3 for holding the lens material W to be processed and the lens material W held by the lens holder 3. A tool pan 4 having a spherical ground surface 4a to be processed is provided.

  The lens holder 3 is fixed to the lower end of the vertical lens spindle 5 with the holding surface 3a held horizontally so that the holding surface 3a faces downward. A suction passage 5 a extending in the axial direction is formed at the center of the lens spindle 5, its lower end opens to the center of the holding surface 3 a of the lens holder 3, and its upper end passes through the rotary joint 6 and the air filter 7. Via the suction side of the vacuum generator 8. By vacuum-suctioning the suction passage 5 a by the vacuum generator 8, the lens material W is sucked and held on the holding surface 3 a of the lens holder 3.

  The lens spindle 5 is coaxially arranged inside a cylindrical vertical holding cylinder 9 whose upper end is sealed, and is supported by the vertical holding cylinder 9 in a rotatable state via a pair of upper and lower bearings 10 and 11. ing. The lens spindle 5 is rotationally driven by a lens shaft rotating motor 12 around a lens rotation center line 5A which is a vertical center line thereof. An air cylinder 13 is connected to the upper end of the vertical holding cylinder 9, and the air cylinder 13 is fixed inside a support cylinder 14 whose upper end is sealed. The vertical holding cylinder 9 is pressed downward by a predetermined force by the air cylinder 13.

  The lens spindle 5 is moved up and down by a workpiece lifting mechanism 20. The workpiece elevating mechanism 20 includes a horizontal arm 21, and the vertical holding cylinder 9 is inserted coaxially into a vertical cylindrical portion 22 attached to the tip of the horizontal arm 21, and the support cylinder 14 is placed on the horizontal arm 21 on the upper surface. It is fixed. The horizontal arm 21 is moved up and down along the vertical linear guide 26 by a lifting mechanism including a feed screw 23, a nut 24, and a servo motor 25.

  Here, the proximity cylinder 27 for detecting the upper end 9a of the vertical holding cylinder 9 attached to the inside of the support cylinder 14 supporting the lens spindle 5 via the air cylinder 13 is attached. . Normally, the proximity sensor 27 is in an off state, and when the vertical holding cylinder 9 rises relative to the support cylinder 14, the upper end 9a is detected by the proximity sensor 27, and the sensor output is turned on.

  Next, the tool plate 4 disposed below the lens holder 3 is disposed such that the spherical center O of the spherical grinding surface 4a is positioned on the extension of the lens rotation center line 5A on the lens holder 3 side. . A spindle 4 b is integrally formed on the back surface of the tool plate 4, and the spindle 4 b is supported in a freely rotatable state by a spherical rocking body 31. Here, the spindle 4b is supported by the ball center rocking body 31 so that the rotation center line 4A of the tool plate 4 intersects the lens rotation center line 5A extending vertically at an acute angle θ at the ball center O. .

  The spherical rocking body 31 includes a hemispherical cup portion 31a and a cylindrical portion 31b projecting radially outward from the outer peripheral surface portion at the center of the bottom of the cup portion 31a, and is coaxial with the cylindrical portion 31b. The spindle 4b is attached in a rotatable state. A flange 31c extends laterally from the lower end of the cylindrical portion 31b, and a spindle driving motor 32 is mounted on the flange 31c.

  The cup portion 31 a of the ball center rocking body 31 is supported by a ring-shaped inner peripheral surface 33 a formed on the support plate 33 in a state in which the ball core can rock. The annular inner peripheral surface 33a is a spherical surface having the spherical center O as a spherical center, and the cup portion 31a having a spherical outer peripheral surface 31d placed on the annular inner peripheral surface 33a can swing around the spherical center O. It is. In this example, a compressed air blowing hole or groove 33b is formed in the annular inner peripheral surface 33a, and the compressed air is supplied to the annular inner peripheral surface 33a through a compressed air supply path 33c. Accordingly, the cup portion 31a is held in a state of being lifted from the annular inner peripheral surface 33a. Therefore, the ball swinging body 31 can be swung smoothly around the ball center O.

  The lower end of the ball swinging body 31 is connected to the output shaft of the electric motor 36 via a link joint 34 and a swinging width adjusting unit 35. The connection point 34a between the ball center rocking body 31 and the link joint 34 is located on the extension line of the tool pan rotation center line 4A, and the rotation center line 36A of the electric motor 36 is always kept facing the ball center O. When the adjustment knob 35a of the swinging width adjustment unit 35 is operated, the distance between the connection point 34a and the rotation center line 36A of the electric motor 36 changes. Therefore, the swing width of the swing motion of the ball center swing body 31 can be adjusted.

  Next, the electric motor 36 is supported by a swing angle adjusting unit 37. The swing angle adjusting unit 37 includes an arcuate cam 38 disposed at a fixed position, and the cam 38 has an arc shape with the sphere center O as the center. A support member 39 is attached so as to be slidable along the cam 38, and an electric motor 36 is attached thereto. A nut 40 is fixed to the support member 39, and a feed screw 41 is screwed into the nut 40. The end of the feed screw 41 is connected to the handle 42.

  When the handle 42 is turned, the support member 39 moves along the cam 38. That is, the tool plate spindle 4b supported by the ball center rocking body 31 rocks by a predetermined amount around the ball center O. Therefore, the swing angle adjusting unit 37 can change the angle θ formed by the rotation center line 4A of the tool plate 4 with respect to the vertical lens rotation center line 5A, that is, the angle of the swing center line.

  Here, the drive control of each part is performed by the controller 50 for numerical control. An input device 51 is connected to the controller 50. Through the input device 51, the lens material can be sent out by manual operation, and the cutting amount can be set.

  FIG. 3A is a cross-sectional view showing a diamond dish type grindstone which is a resin bond grindstone for rough grinding, and FIG. 3B is a partially enlarged cross-sectional view thereof. FIG. 3C is a partially enlarged cross-sectional view showing a diamond dish type grindstone before co-friction correction. The diamond plate type grindstone shown in FIGS. 3A and 3B is used as the tool plate 4 in the case of performing rough grinding using the spherical center rocking type grinder described above.

  The diamond dish type grindstone 60 has a tool dish body 62 having a spherical surface 61 complementary to a lens spherical surface to be processed, and an abrasive layer 63 having a constant thickness laminated on the spherical surface 61. Yes. The abrasive layer 63 is made of an abrasive in which diamond abrasive grains 65 are dispersed and mixed with the bond material 64 at a predetermined concentration (concentration). In this example, a diamond pellet 66 having a certain size is adhered and fixed to the spherical surface 61 at a predetermined interval.

  A large number of diamond abrasive grains 65 protrude from the surface 63a of the abrasive layer 63 with different protrusion amounts. As shown in FIG. 3C, the difference ΔH between the maximum protrusion amount and the minimum protrusion amount of the diamond abrasive grains 65 is large at the stage where the diamond pellet 66 is bonded and fixed. In this example, the diamond abrasive grains 65 protruding from the surface 63a of the abrasive layer 63 are subjected to co-rubbing correction processing. As a result, the tip portion on the protruding side of a part of the diamond abrasive grains 65 is polished, and the difference ΔH between the maximum protruding amount H1 and the minimum protruding amount H2 of the diamond abrasive grains 65 is a predetermined value or less. For example, the difference ΔH between the maximum protrusion amount H1 and the minimum protrusion amount H2 of the diamond abrasive grains 65 is in the range of 1/3 to 1/6 of the average particle diameter of the diamond abrasive grains.

  Next, FIGS. 4A to 4E are explanatory views showing an example of a method for producing a diamond dish type grindstone. The method for producing a diamond dish type grindstone includes an abrasive layer forming process (FIGS. 4A and 4B) and a co-rubbing correcting process (FIGS. 4C to 4E).

  In the abrasive layer forming step, an abrasive material in which diamond abrasive grains are dispersed and mixed in a bond material on a spherical surface of a tool plate body having a spherical surface complementary to the lens spherical surface to be processed is fixed in thickness. The abrasive layer is formed by laminating. For example, a fixed plate 71 having a spherical surface with a spherical accuracy (Δh) of 0.002 μm to 0.005 μm with respect to the lens spherical surface to be processed is manufactured (FIG. 4A). Next, diamond pellets 66 having a fixed thickness in which diamond abrasive grains are dispersed and mixed in a bonding material are attached to the spherical surface 72 of the fixed plate 71 with glue or the like. An adhesive 74 is applied to each surface of the adhered diamond pellet 66. Next, each of the diamond pellets 66 affixed to the spherical surface 72 is pressed against the spherical surface 61 of the tool plate main body 62 via the adhesive 74, and this pressed state is maintained until the adhesive is cured. After the adhesive is cured, the fixed plate 71 is removed to obtain the tool plate main body 62 in which the abrasive material layer 63 made of the diamond pellets 66 is formed on the spherical surface 61 (FIG. 4B). FIG. 3C shows the formed abrasive layer 63 in an enlarged manner.

  In the next co-friction correction step, the surface of the abrasive layer of the tool plate body is subjected to co-rub correction using a co-friction correction plate having a spherical co-friction surface corresponding to the lens spherical surface to be processed, and the abrasive The difference between the maximum protrusion amount and the minimum protrusion amount in the diamond abrasive grains protruding from the surface of the material layer is set to a predetermined value or less. For example, the co-rubbing correction process includes a rough correction process and a finish correction process.

  In the rough correction process, the surface of the abrasive layer 63 is subjected to co-friction correction while applying abrasive grains having a predetermined particle diameter using a co-rubbing rough correction plate 73 (FIG. 4C). For example, co-rubbing correction is performed while applying GC # 240 abrasive grains (silicon-based abrasive).

  In the finishing correction step, the surface of the abrasive layer 63 after the rough correction is subjected to co-rubbing finishing correction while applying only water using a co-rubbing finishing correction plate 75 (FIGS. 4D and 4E). For example, the co-rubbing finish correcting plate 75 is manufactured and quenched using a material that can be quenched, such as S45C. Since the deformation is caused by quenching, the spherical accuracy (Δh) of the spherical co-rubbed surface is 0.002 μm to 0.005 μm with respect to the lens spherical surface to be processed. Modify as follows. The co-rubbing finishing plate 75 obtained in this way is used. FIG. 3B shows the abrasive layer 63 after correction in an enlarged manner.

(Function and effect)
Using the diamond plate-type grindstone 60 manufactured as described above, the spherical lens was roughly ground using the spherical rocking grinding device 1 shown in FIG. As a result, although the # 100 to # 400 diamond dish type grindstone 60 was used, the cutting flaw on the lens grinding surface was around 10 μm. Further, the cutting speed of the lens material (BK7, φ30) made of boron silica glass was 20 μm / second, and a 700 μm cutting amount could be processed in about 35 seconds. Moreover, it was confirmed that since the particle size is large, there is little wear and the deterioration of the surface accuracy of the ground surface is small.

  Furthermore, in the next precision grinding process, the machining allowance can be reduced to about 10 μm, and it has been confirmed that only a single precision grinding process using a resin bond grindstone is sufficient. Therefore, it was confirmed that the spherical lens can be efficiently ground in a short grinding time as a whole as compared with the conventional spherical lens grinding method.

DESCRIPTION OF SYMBOLS 1 Ball center rocking type grinding device 3 Lens holder 4 Tool plate 4a Spherical grinding surface 4A Tool plate rotation center line 5 Lens spindle 5A Lens rotation center line 20 Work lifting mechanism 21 Horizontal arm 31 Ball center rocking body 33 Support plate 33a Circle Annular inner peripheral surface 33b Compressed air blowing hole or groove 35 Oscillation width adjustment unit 36A Rotation center line 37 Oscillation angle adjustment unit W Lens material O Ball center 60 Diamond plate type grindstone 61 Spherical surface 62 Tool plate body 63 Abrasive material layer 64 Bond material 65 Diamond abrasive grains 66 Diamond pellet 71 Fixed plate 72 Spherical surface 73 Co-rubbing rough correction plate 74 Adhesive 75 Co-rubbing finish correction plate H1 Maximum protrusion amount H2 Minimum protrusion amount ΔH Difference

Claims (7)

It has a tool plate body having a spherical surface complementary to the lens spherical surface to be processed, and an abrasive layer of a certain thickness laminated on the spherical surface,
The abrasive layer is made of an abrasive in which diamond abrasive grains are dispersed and mixed in a bond material,
Many diamond abrasive grains protrude from the surface of the abrasive layer,
The diamond grindstone protruding from the surface of the abrasive layer is subjected to co-rubbing correction processing, and the difference between the maximum protrusion amount and the minimum protrusion amount of the diamond abrasive grains is a predetermined value or less. Diamond dish type grindstone for spherical lens processing. In claim 1,
The diamond dish type grindstone characterized in that a difference between the maximum protrusion amount and the minimum protrusion amount of the diamond abrasive grains is within a range of 1/3 to 1/6 of the particle diameter of the diamond abrasive grains. In claim 1 or 2,
The diamond abrasive grain according to claim 1, wherein the diamond grain has an average grain size of 149 to 37 μm (JIS general grain size: # 100 to # 400). In any one of claims 1 to 3,
The abrasive layer is formed by adhering and fixing diamond pellets of a certain thickness made of an abrasive in which diamond abrasive grains are dispersed and mixed in a bond material to the spherical surface of the tool plate body at predetermined intervals. A diamond dish type whetstone characterized by   A spherical lens grinding method, comprising grinding a lens spherical surface of a spherical lens using the diamond dish type grindstone according to any one of claims 1 to 4. In claim 5,
A rough grinding step of roughly creating a lens spherical surface by rough grinding the lens surface of the lens material to be processed using the diamond dish type grindstone,
A fine grinding process for finely grinding the created rough grinding lens spherical surface using a fine grinding tool plate;
A polishing step of polishing the lens spherical surface after fine grinding,
In the rough grinding process,
The diamond dish-type grindstone is rotated about a rotation center line passing through the spherical center of the spherical surface, and the diamond dish-type grindstone is drawn so that the rotation center line has a conical surface with the sphere center at the top. Sway the ball center,
While rotating the lens material in the same direction as the diamond dish type grindstone, press against the diamond dish type grindstone,
A spherical lens grinding method, wherein the lens material is subjected to spherical grinding while feeding the lens material in this state. In claim 6,
The average particle size of the diamond abrasive grains is 149 to 37 μm (JIS general abrasive grain size: # 100 to # 400),
The machining allowance in the fine grinding step is set to 20 μm or less,
A spherical lens grinding method, wherein the fine grinding step is a single grinding step.

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