JP2011093044A - Rough grinding method for lens and lens rough grinding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of chipping at spark-in in a lens rough grinding method in which rough grinding of a lens to be machined is performed by pressing the lens to be machined to a rotated and rocked lens machining dish. <P>SOLUTION: The lens 9 to be machined is vacuum-sucked to a lens holder 7 (ST1), the lens 9 to be machined is pressed to the lens machining dish 8 (ST3), initial rough grinding is applied to the lens 9 to be machined vacuum-sucked to the lens holder 7 while rotating the lens holder 7 together by rotating the lens machining dish 8 (ST4), and the rough grinding of the lens 9 to be machined is performed while rotating and rocking the lens machining dish 8 (ST6). Since the lens machining dish 8 is only rotated at the initial rough grinding, large vibration is not applied to the lens 9 to be machined at spark-in, the lens 9 to be machined is retained in the stable state by the lens holer 7, chipping is not generated, the lens 9 to be machined is not center-deviated in the lens holder 7, and deviation of thickness is generated neither. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  In the present invention, the processing surface of the lens to be processed that is sucked and held by the lens holding surface of the lens holder is pressed against the spherical processing surface of the lens processing plate, and the lens processing plate is swung while rotating around its central axis. The present invention relates to a lens rough grinding method and a lens rough grinding machine for roughly grinding a workpiece lens by moving the lens.

  A lens rough grinding machine for roughly grinding a lens to be processed while rotating and swinging a lens processing plate is disclosed in, for example, Patent Document 1 by the present applicant. The lens grinding machine disclosed here grinds the lens to be processed while rotating the diamond tool plate and swinging the ball center. The lens to be processed is vacuum-adsorbed and held on a lens holder. The lens to be processed is cut by forcibly rotating at the same speed in the same direction as the direction of rotation of the tool plate and continuously feeding a table that supports the lens holder according to the cutting amount of the lens to be processed.

JP 2003-340702 A

  Here, when the lens to be processed is cut while forcibly rotating at the same speed in the same direction as the diamond processing pan, the side on which the swinging deflection angle is large and the side on which the diamond processing pan is swinging are swung. However, there is a slight difference in the peripheral speed between the lens to be processed and the diamond processing dish. In particular, when the rocking deflection angle is large, the peripheral speed difference is increased, and the uneven wear of the processed surface of the diamond processing pan tends to proceed.

  In order to avoid uneven wear of the diamond processing plate, the lens holder may be rotatably supported so as to rotate with the rotation of the diamond processing tool. However, in this case, spark-in is performed with respect to the diamond processing dish that is rotating and swinging simultaneously. In other words, since the non-rotated workpiece lens contacts the rotating and swinging diamond processing tool, when sparking in, the workpiece lens vibrates in the lens holder due to the rotation of the diamond processing pan, causing burrs and cracks. There is a possibility that it will occur, or the center of the lens holder will be misaligned and a flesh will be generated. In particular, when the swing angle is large, such an adverse effect appears remarkably.

  Moreover, such an adverse effect appears notably in a diamond processing dish in which diamond in a pellet state is attached to the processing surface. This is because, as shown in FIG. 4, the processed surface 109a of the lens 109 to be processed has a marking 109b or a non-smooth surface portion 109c, so that the friction during spark-in becomes very large. Is the main cause. If the diamond processing tool of the total type is used, tingling and chipping will be somewhat reduced, but it cannot be completely prevented. In addition, since the diamond tool of the total type is expensive, there is a problem that the cost is increased.

  On the other hand, there is the following problem when the lens to be processed that is vacuum-sucked by the lens holder is rotated by the lens holder without being forced to rotate. A mechanism shown in FIG. 5 is generally used as a mechanism for vacuum-sucking the lens to be processed to the lens holder. As shown in FIG. 5A, when the workpiece lens 109 is vacuum-sucked to the lens holder 107, the tip opening 129d of the vacuum suction hole 129c extending through the center of the holder spindle 129 is vacuum-sucked. Air leakage is prevented by pressing against the open end face of the pipe 130 via the seal ring 131.

  If the holder spindle 120 is rotated while the holder spindle 129 is pressed against the vacuum suction pipe 130, a large load is applied to the rotation. As a result, the processed lens 109 held by the lens holder 107 of the holder spindle 129 cannot be smoothly rotated in a dependent manner by following the rotation of the diamond processing plate 108. Therefore, when the holder spindle 129 is rotated following, the pressed state of the holder spindle 129 and the vacuum suction pipe 130 is released as shown in FIG.

  However, if vacuum suction is performed in a state where the holder spindle 129 and the vacuum suction pipe 130 are separated from each other, air leaks through the portion of the rolling bearing 132 and the suction holding force of the lens 109 to be processed becomes weak. The evil that occurs occurs. That is, the holder spindle 129 is held coaxially in the hollow portion 126 a of the hollow shaft 126 and is held in a rotatable state by the rolling bearing 132. When the holder spindle 129 disposed in the hollow portion 126a and the vacuum suction pipe 130 are separated, air flows from the outside into the vacuum suction path through the gap in the portion of the rolling bearing 131 and the hollow portion 126a, and the vacuum suction force May weaken. If the workpiece lens 109 is not securely held with respect to the lens holder 107, vibration or center misalignment is likely to occur in the workpiece lens 109 at the initial stage of rough grinding, resulting in burrs, chips, or flesh. Since possibility becomes high, it is not preferable.

  In view of such a point, the present invention has an object to provide a rough grinding method for a lens in which a lens to be processed is pressed against a rotating and swinging lens processing plate to perform rough grinding of the lens to be processed. The purpose is to be able to prevent or suppress the occurrence of tingling and chipping.

  Another object of the present invention is to propose a lens rough grinding machine that performs rough grinding by such a rough grinding method for lenses.

  In order to solve the above-described problems, the lens rough grinding method of the present invention includes the following steps. Reference numerals in parentheses indicate corresponding portions in the embodiments described later, are added for the purpose of facilitating understanding, and are intended to limit the present invention to the embodiments. is not.

That is, the rough grinding method of the lens of the present invention,
A lens suction step (ST1) for vacuum-sucking the processed lens (9) to the lens holding surface (7a) of the lens holder (7);
The processed surface (9a) of the processed lens (9) adsorbed on the lens holding surface (7a) is used as a spherical processed surface (8a) of a lens processing dish (8) using diamond pellets or diamond. ) Pressing step (ST3),
The lens processing plate (8) is rotated around its central axis (4a) and the lens holder (7) is rotated around its central axis (2a) while being vacuum-adsorbed to the lens holder (7). A first rough grinding step (ST4, ST5) for subjecting the work surface (9a) of the work lens (9) to rough surface grinding;
The lens processing pan (8) continues to rotate, and the lens processing pan (8) is swung at a predetermined swing swing angle (θmax) about the spherical center (8b) of the processing surface (8a). However, it has a second rough grinding step (ST6, ST7) in which a predetermined amount of rough grinding is performed on the work surface (9a).

  In the method of the present invention, the lens to be processed is rotated around the lens processing plate (dependent rotation). Therefore, as in the case where the lens to be processed is forcibly rotated, a difference in peripheral speed occurs between the lens to be processed and the lens processing pan on the side where the swinging deflection angle of the lens processing pan is large and the side where the swinging deflection angle is small. Thus, it is possible to avoid the adverse effect that the rough grinding accuracy of the lens to be processed is lowered.

  In addition, during the first rough grinding, the lens processing pan is only rotated without being swung, so that there is no significant vibration applied to the processed lens during spark-in, and the processed lens is stabilized by the lens holder. Therefore, no tingling or chipping occurs, and the lens to be processed does not decenter in the lens holder, and no flesh is generated.

  Here, in order to reduce the moment acting on the lens to be processed from the lens processing plate at the spark-in, in the first rough grinding step, the central axis of the lens processing plate with respect to the central axis of the lens holder The surface rough grinding may be performed in a state where the angle formed by is set to an angle smaller than the swing swing angle in the second rough grinding step. The smaller the angle, the smaller the acting moment.

  Further, by performing rough surface grinding until the surface of the lens to be processed is engraved and the rough surface disappears, it is possible to reliably prevent generation of burrs and chips. Accordingly, in the first rough grinding step, the rough grinding amount of the work surface is monitored, and after the rough grinding amount reaches the set surface grinding amount to such an extent that the marking and the rough surface are eliminated, It is desirable to move to a rough grinding process.

  In the second rough grinding step, it is also possible to perform rough grinding with the vacuum suction of the lens to be processed being released.

Next, the lens rough grinding machine (1) of the present invention comprises:
A hollow shaft (26);
A holder spindle (29) rotatably held coaxially in the hollow portion (26a) of the hollow shaft (26);
A lens holder (7) attached coaxially to the end of the holder spindle (29);
A lens processing plate (8) having a spherical processing surface (8a) facing the lens holding surface (7a) of the lens holder (7);
A processing plate spindle (41) supporting the lens processing plate (8);
A rotating mechanism (42) for rotating the processing plate spindle (41) about its central axis (4a);
With the ball center (8b) of the processing surface (8a) positioned on the center axis (4a) of the holder spindle (29), the processing plate spindle (41) is swung around the ball center (8b). A swing mechanism (42) to be moved;
The hollow shaft (26) is urged in the axial direction so that the processing surface (9a) of the processing lens (9) held by the lens holder (7) is processed in the lens processing plate (8). An urging mechanism (27) that forms a pressed state on the surface (8a);
A vacuum suction mechanism (7b, 29c, 26a, 25, 32, 33) for vacuum-sucking the lens (9) to be processed to the lens holding surface (7a) of the lens holder (7);
A controller (6) for controlling the drive of each part,
The controller (6) drives and controls the rotation mechanism, the swinging mechanism, the biasing mechanism, and the vacuum suction mechanism, and performs rough grinding on the lens to be processed by the above-described lens rough grinding method. It is a feature.

  Here, it has a measuring device which measures the amount of rough grinding of the lens to be processed by the lens processing plate, and the controller is based on the measurement value by the measuring device, from the first rough grinding step to the second rough grinding step. Control can be switched to.

  The vacuum suction mechanism has one end opened in the lens holding surface, extends through the center of the lens holder and the holder spindle, and the other end communicates with the hollow portion of the hollow shaft. If the vacuum suction hole is provided, an annular minute gap of a predetermined length communicating with the hollow portion, a grease reservoir, and a rolling bearing are provided between the hollow shaft and the holder spindle. When the hollow portions are vacuum-sucked in this order, the grease in the grease pool is sucked into the minute gaps, and the minute gaps are blocked by the viscous resistance of the grease, and the hollow shaft and the holder It is desirable to keep the space between the spindles airtight.

  In this way, it is possible to prevent air from entering the vacuum suction path from the outside and reducing the vacuum suction force of the lens to be processed. Therefore, the lens to be processed can be held in a stable state by the lens holder during rough grinding.

  In the present invention, in the initial state of processing, the lens processing tool is rotated to roughly grind the surface of the processing lens dependently rotated by the lens processing tool, and then the lens processing tool is rotated and swung while the lens processing tool is rotated and swung. Rough grinding is performed. Therefore, it is possible to solve the conventional problem that the lens to be processed vibrates in the lens holder during spark-in, and the flakes, burrs, and chips tend to occur, and the processing accuracy can be stabilized.

It is a schematic block diagram which shows the lens rough grinding machine to which this invention is applied. It is a partial expanded sectional view which shows the principal part of the lens rough grinding machine of FIG. It is a flowchart which shows the rough grinding operation | movement of the lens rough grinding machine of FIG. It is explanatory drawing which shows the state before the process start of a to-be-processed lens and a lens processing pan. It is explanatory drawing which shows the structure and operation | movement of the conventional lens rough grinding machine which does not perform vacuum suction of a to-be-processed lens during a process.

  Embodiments of a rough lens grinding machine to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
Referring to FIGS. 1 and 2, the lens rough grinding machine 1 according to the present embodiment includes an upper shaft unit 2, a lower shaft unit 4, and a controller 6 that drives and controls them. The upper shaft unit 2 includes a lens holder 7 attached downward, and the lower shaft unit 4 includes a lens processing tray 8 attached upward.

  The upper shaft unit 2 includes an elevating table 21, and the elevating table 21 is moved up and down by a linear motion mechanism including an upper shaft motor 22 (servo motor), a ball screw 23, and a ball nut 24. A shaft support cylinder 25 is fixed vertically to the elevating table 21, and a hollow shaft 26 is held vertically by the shaft support cylinder 25 and can move in the direction of the central axis. The lower end of the telescopic rod 27a of the air cylinder 27 that is vertically attached to the shaft support cylinder 25 is connected and fixed to the upper end of the hollow shaft 26 in a coaxial state. With the air cylinder 27, the hollow shaft 26 can be urged downward with a predetermined pressing force. Driving air is supplied to the air cylinder 27 via an air regulator 28.

  The lower part of the hollow shaft 26 protrudes downward from the lower end of the shaft support cylinder 25, and a holder spindle 29 is coaxially inserted into the hollow part 26a of the lower part from the lower side. The holder spindle 29 includes a head portion 29a that protrudes downward from the lower end of the hollow shaft 26, and a shaft portion 29b that extends coaxially from the upper end in the hollow portion 26a. The shaft portion 29b includes: Two portions separated in the vertical direction are supported by the circular inner peripheral surface of the hollow shaft 26 in a rotatable state via a rolling bearing 30 in a rotatable state.

  The lens holder 7 is fixed to the head 29a at the lower end of the holder spindle 29 by screwing downward in a coaxial state from below. The lens holder 7 includes a downward lens holding surface 7a and a vacuum suction hole 7b extending through the center in the vertical direction, and the lower opening of the vacuum suction hole 7b is exposed to the lens holding surface 7a. . The upper end opening of the vacuum suction hole 7 b communicates coaxially with the lower end opening of the vacuum suction hole 29 c opened at the center of the holder spindle 29.

  The upper end of the hollow portion 26 a of the hollow shaft 26 is connected to an external vacuum generation source 33 through a vacuum suction passage 31 and an electromagnetic valve 32. When evacuation is performed by the vacuum generation source 33 in a state where the lens 9 to be processed is attached to the downward lens holding surface 7a of the lens holder 7, the lens 9 to be processed is vacuum-sucked by the lens holding surface 7a and held there. A state is formed.

  Next, the lower shaft unit 4 includes a processing plate spindle 41, and the lens processing plate 8 is coaxially attached to the upper end portion of the processing plate spindle 41 in an upward state. The lens processing plate 8 has a concave spherical surface on its upward processing surface 8a. The lens processing dish 8 is a diamond processing dish using diamond pellets or total diamond.

  The processing plate spindle 41 is rotated and oscillated by a processing plate driving mechanism 42. That is, the processing plate drive mechanism 42 includes a rotation mechanism that rotates the processing plate spindle 41 about its central axis 41a. Further, the processing dish driving mechanism 42 includes a ball center swinging mechanism that swings the processing dish spindle 41 with a predetermined swing angle around the center of the processing surface 8a. The upper shaft unit 2 and the lower shaft unit 4 are arranged so that the spherical center position of the processing surface 8a is located on the center axis of the holder spindle 29 of the upper shaft unit 2.

  In the upper shaft unit 2, a length measuring plate 34 is attached to the hollow shaft 26 extending in a direction orthogonal to the outer peripheral surface thereof. A length measuring device 35 is attached to the outer peripheral surface of the shaft support cylinder 25, and the needle 35 a is pressed against the length measuring plate 34 vertically from above. As the amount of rough grinding of the processing surface 9a of the processing lens 9 by the lens processing pan 8 increases, the hollow shaft 26 moves downward relative to the shaft support cylinder 25. Therefore, the rough grinding amount can be measured by the length measuring device 35.

  Here, the drive control of each part is performed by the controller 6. A detection signal from the length measuring device 35 is input to the controller 6, and the upper shaft motor 22 is driven and controlled based on a command from the controller 6, and the air cylinder 27 is driven and controlled via the air regulator 28, and the solenoid valve The vacuuming operation is controlled via 32. In addition, the processing dish driving mechanism 42 is driven and controlled by the controller 6.

(Vacuum suction path seal mechanism)
As described above, the shaft portion 29b of the holder spindle 29 is supported by the circular inner peripheral surface 26b of the hollow shaft 26 via the rolling bearing 30 at a position separated vertically. Between the shaft portion 29 b and the hollow shaft 26, a grease reservoir 36 having an annular rectangular cross section is mounted on the upper side of the upper rolling bearing 30 at a predetermined interval. Grease is held in the grease reservoir 36. A cylindrical collar 37 having a predetermined length is disposed above the grease reservoir 36. The collar 37 is fixed to the inner peripheral surface of the hollow shaft 26, and an annular minute gap between the circular inner peripheral surface 37a and the outer peripheral surface of the shaft portion 29b opposite to the circular inner peripheral surface 37a, for example, about 10 microns. The minute gap 38 is formed.

  In this example, the outer peripheral edge portion of the lower end portion of the collar 37 protrudes downward, and a grease reservoir 36 is formed on the inner side. Further, the upper end surface of the collar 37 is prevented from being pulled upward by a stop ring 39 attached to the upper end portion of the shaft portion 29b.

(Coarse grinding operation)
The rough grinding operation by the lens rough grinding machine 1 having the above configuration will be described mainly with reference to the flowchart of FIG. First, in a standby state where the upper shaft unit 2 and the lower shaft unit 4 are vertically separated, the lens 9 to be processed is attached to the lens holding surface 7a of the lens holder 7 of the upper shaft unit 2 using a lens transfer tool or the like. Vacuuming is performed, and the lens 9 to be processed is sucked and held on the lens holding surface 7a (step ST1 in FIG. 3).

  Here, when the evacuation is started by opening the electromagnetic valve 32, the degree of vacuum of the hollow portion 26a of the hollow shaft 26 serving as a vacuum suction path is increased. As a result, the outside air passes through the clearance of the rolling bearing 30 and enters the hollow portion 26 a through the grease reservoir 36 and the minute clearance 38 between the shaft portion 29 b of the holder spindle 29 and the collar 37. When this air enters, the grease in the grease reservoir 36 also flows toward the minute gap 38 together. Since the viscous resistance of grease is large, when the grease flows into the minute gap 38, the minute gap 38 is sealed in an airtight state. As a result, intrusion of outside air is prevented or suppressed, and the degree of vacuum in the hollow portion 26a can be maintained. Therefore, the workpiece lens 9 is securely held on the lens holding surface 7 a of the lens holder 7.

  Thereafter, the swinging deflection angle of the lens processing pan 8 of the lower shaft unit 4 is set to a predetermined minimum value θmin. That is, as shown in FIG. 2, the angle formed by the central axis 4a of the lens processing plate 8 of the lower shaft unit 4 with respect to the central axis 2a of the lens holder 7 of the upper shaft unit 2 is set to a minimum value θmin. Setting is made (step ST2 in FIG. 3).

  Next, the elevating table 21 is lowered so that the processing surface 9a of the processing lens 9 faces the processing surface 8a of the lower lens processing tray 8, the air cylinder 27 is driven, and the processing is performed with a constant pressing force. A state is formed in which the lens 9 is pressed against the lens processing plate 8 (step ST3 in FIG. 3). FIG. 1 and FIG. 2 show this state.

  Next, the processing plate driving mechanism 42 starts rotating the lens processing plate 8 about its central axis 4a (step ST4 in FIG. 3). Since the lens holder 7 holding the lens 9 to be processed is held in a freely rotatable state by the hollow shaft 26, surface rough grinding is performed while the lens processing pan 8 is rotated (dependent rotation). It is applied to the work surface 9a of the lens 9 (first rough grinding operation).

  Here, as described with reference to FIG. 4, in the initial stage of processing, the processed surface 9 a of the processed lens 9 is engraved and the surface is rough. The frictional resistance between them is large. In this example, the lens 9 to be processed is securely held by the lens holder 7 as described above. Further, the lens processing plate 8 does not perform a swinging motion, but only performs a rotational motion, so that a large moment does not act on the processed lens 9 held by the lens holder 7. Therefore, it is possible to avoid or suppress the problem that the lens 9 to be processed held by the lens holder 7 is vibrated and misaligned to cause flesh, burrs, chipping, and the like.

  In this rough surface grinding, the controller 6 monitors the rough surface grinding amount based on the detection signal of the length measuring device 35. Surface rough grinding is performed until the surface rough grinding amount reaches a preset set surface grinding amount (steps ST4 and ST5 in FIG. 3), and thereafter, the process proceeds to the second rough grinding operation.

  In the second rough grinding operation, while maintaining the rotational motion of the lens processing pan 8, the lens processing pan 9 is moved while swinging the lens processing pan 8 about the spherical center 8b of the processing surface 8a at the maximum swing angle θmax. Rough grinding is performed (step ST6 in FIG. 3). Further, the pressure of the air regulator 27 is increased to increase the pressing force by the air cylinder 27. Also in this second rough grinding, the controller 6 monitors the rough grinding amount, and when the rough grinding amount reaches a preset cutting completion value (when the constant-size grinding is completed), the lens processing pan. 8 is stopped and the grinding operation is finished (steps ST6, ST7, ST8).

  Thereafter, the lens 9 to be processed is moved upward from the lens processing plate 8 (step ST9 in FIG. 3), the lens transfer tool and the like are moved to the receiving position directly below the lens 9 to be processed, and the vacuuming is released. Then, the processed lens 9 that has been processed is released from the lens holder 7 and delivered to a lens transfer tool or the like (step ST10 in FIG. 3).

  Note that after the initial roughing is completed, it is possible to release the vacuuming and perform the subsequent rough grinding operation. Such a processing state can be selected according to the state of the lens 9 to be processed.

  In this example, the length measuring device switches from the initial grinding operation to the main grinding operation based on the cutting amount. Instead, as a simple switching control method, switching control is performed based on the cutting time using a timer. It is also possible to perform.

(Other embodiments)
In the lens rough grinding machine, a lens holder is attached to the lower end of the upper shaft unit, and a convex spherical lens is sucked and held here to perform rough grinding. It is also possible to arrange the upper shaft unit and the lower shaft unit upside down. The above example is an example of rough grinding of a convex spherical lens, but the present invention is naturally applicable to the case of rough grinding of a concave spherical lens.

DESCRIPTION OF SYMBOLS 1 Lens coarse grinding machine 2 Upper shaft unit 4 Lower shaft unit 6 Controller 7 Lens holder 7a Lens holding surface 8 Lens processing plate 8a Processing surface 8b Ball center 9 Processing lens 9a Processing surface 21 Lifting table 22 Upper shaft motor 23 Ball screw 24 Ball nut 25 Shaft support cylinder 26 Hollow shaft 26a Hollow portion 26b Inner circumferential surface 27 Air cylinder 27a Telescopic rod 28 Air regulator 29 Holder spindle 29a Head 29b Shaft portion 29c Vacuum suction hole 30 Rolling bearing 31 Vacuum suction path 32 Solenoid valve 33 Vacuum generating source 34 Measuring plate 35 Measuring device 35a Measuring needle 36 Grease reservoir 37 Collar 37a Inner peripheral surface 38 Small gap 39 Stop ring 41 Processing pan spindle 42 Processing pan drive mechanism

Claims (7)

A lens suction step (ST1) for vacuum-sucking the processed lens (9) to the lens holding surface (7a) of the lens holder (7);
The processed surface (9a) of the processed lens (9) adsorbed on the lens holding surface (7a) is used as a spherical processed surface (8a) of a lens processing dish (8) using diamond pellets or diamond. ) Pressing step (ST3),
The lens processing plate (8) is rotated around its central axis (4a) and the lens holder (7) is rotated around its central axis (2a) while being vacuum-adsorbed to the lens holder (7). A first rough grinding step (ST4, ST5) for subjecting the work surface (9a) of the work lens (9) to rough surface grinding;
The lens processing pan (8) continues to rotate, and the lens processing pan (8) is swung at a predetermined swing swing angle (θmax) about the spherical center (8b) of the processing surface (8a). The lens rough grinding method, further comprising a second rough grinding step (ST6, ST7) for subjecting the work surface (9a) to a predetermined amount of rough grinding. In claim 1,
In the first rough grinding step, an angle formed by the center axis (4a) of the lens processing dish (8) with respect to the center axis (2a) of the lens holder (7) is set in the second rough grinding step. A rough grinding method for a lens, wherein the rough surface grinding is performed in a state where the angle (θmin) is smaller than the swinging swing angle (θmax). In claim 2,
In the first rough grinding step, the surface rough grinding amount of the work surface (9a) is monitored (ST5),
When the surface rough grinding amount reaches a predetermined set surface rough grinding amount, the process proceeds to the second rough grinding step (ST6). In claim 3,
In the second rough grinding step (ST6), the rough grinding method of the lens is characterized in that rough grinding is performed in a state where the vacuum suction of the processed lens (9) is released. A hollow shaft (26);
A holder spindle (29) rotatably held coaxially in the hollow portion (26a) of the hollow shaft (26);
A lens holder (7) attached coaxially to the end of the holder spindle (29);
A lens processing plate (8) having a spherical processing surface (8a) facing the lens holding surface (7a) of the lens holder (7);
A processing plate spindle (41) supporting the lens processing plate (8);
A rotating mechanism (42) for rotating the processing plate spindle (41) about its central axis (4a);
With the ball center (8b) of the processing surface (8a) positioned on the center axis (4a) of the holder spindle (29), the processing plate spindle (41) is swung around the ball center (8b). A swing mechanism (42) to be moved;
The hollow shaft (26) is urged in the axial direction so that the processing surface (9a) of the processing lens (9) held by the lens holder (7) is processed in the lens processing plate (8). An urging mechanism (27) that forms a pressed state on the surface (8a);
A vacuum suction mechanism (7b, 29c, 26a, 25, 32, 33) for vacuum-sucking the lens (9) to be processed to the lens holding surface (7a) of the lens holder (7);
A controller (6) for controlling the drive of each part,
The controller (6) drives and controls the rotation mechanism, the swing mechanism, the urging mechanism, and the vacuum suction mechanism, and performs rough grinding on the lens to be processed by the method of rough grinding a lens according to claim 1. A lens rough grinding machine (1) characterized in that it performs. In claim 5,
Measuring instruments (35, 34) for measuring the amount of rough grinding of the lens (9) to be processed by the lens processing pan (8);
The lens rough grinding machine (1), wherein the controller (6) switches the control from the first rough grinding step to the second rough grinding step based on a measurement value by the measuring instrument. In claim 5,
The vacuum suction mechanism has one end opened to the lens holding surface (7a), extends through the centers of the lens holder (7) and the holder spindle (29), and the other end is the hollow shaft ( A vacuum suction hole (7b, 29c) communicating with the hollow part (26a) of 26),
Between the hollow shaft (26) and the holder spindle (29), an annular minute gap (38) having a predetermined length communicating with the hollow portion (26a), a grease reservoir (36), Rolling bearings (30) are arranged in this order,
When the hollow portion (26a) is vacuumed, the grease in the grease reservoir (36) is sucked into the minute gap (38), and the minute gap (38) is blocked by the viscous resistance of the grease, The lens rough grinding machine (1), wherein the space between the hollow shaft (26) and the holder spindle (29) is maintained in an airtight state.

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