JP2000108001A - Lens grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens grinding device for reducing abrasion in a specific place of the abrasive surface of a grinding wheel to improve work efficiency in the grinding wheel, and correctly grind-working a lens to be worked based on globe type shape data while considering abrasion loss in the abrasive surface of the grinding wheel. SOLUTION: This device has a contact position setting means D for setting the contact position of a lens L to be worked with an abrasive surface 12a, and an arithmetic controlling means F for controlling a center distance adjusting means C so as to movably adjust lens holding shafts 22a and 22b in an axial direction to contact positions 12a1 and 12a2 set by the means D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens grinding apparatus which grinds a lens to be processed into a lens shape by using a grinding wheel driven to rotate.

[0002]

2. Description of the Related Art As shown in FIG. 8, a conventional lens grinding apparatus includes a lens to be processed (unprocessed circular cloth lens) L
Is held between the lens holding shafts 1 and 2, the grinding wheel 3 whose axis is parallel to the axis of the lens holding shafts 1 and 2 is rotationally driven, and the lens holding shafts 1 and 2 are By controlling the advance / retreat movement of the grinding wheel 3, the peripheral edge of the lens L to be processed is brought into contact with the polished surface 3a of the peripheral surface of the grinding wheel 3, and the lens L to be processed is shaped into a spectacle lens (ball shape). Some are designed to be ground.

[0003]

However, in the conventional lens grinding apparatus, the peripheral edge of the lens L to be processed is limited to a specific portion of the polishing surface 3a of the grinding wheel 3 (usually, the central portion 3b in the width direction of the polishing surface 3a). Was ground in contact with
The wear of a specific portion of the grinding wheel 3 becomes remarkable, and the grinding wheel 3
Had to be replaced frequently.

For this reason, conventionally, the operator has switched the position of the polishing surface 3a with which the peripheral edge of the lens to be processed comes into contact in a direction (width direction) parallel to the axis of the grinding wheel, but it takes time and skill. In short, especially for beginners of the processing technology for processing the lens to be processed, there is a possibility that the working efficiency is reduced.

As a lens grinding apparatus for automatically adjusting the movement, for example, Japanese Patent Application Laid-Open No. 9-225799
There is an apparatus as disclosed in Japanese Unexamined Patent Application Publication No. HEI 9-86. However, in this apparatus, the contact position of the lens to be processed with the grinding wheel is simply adjusted automatically in the direction along the axis of the grinding wheel (the width direction of the grinding wheel). Since the contact position of the lens to be processed with the grinding wheel cannot be changed in consideration of the amount of wear of the surface and the like, there is a possibility that the lens to be processed cannot be accurately ground based on the ball shape data.

Accordingly, the present invention can improve the working efficiency of the grinding wheel by reducing the abrasion of a specific portion of the grinding surface of the grinding wheel, and can reduce the wear on the polishing surface of the grinding wheel. It is an object of the present invention to provide a lens grinding apparatus capable of setting a contact position of a processing lens with a grindstone and accurately grinding a lens to be processed based on sphere shape data.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a lens holding shaft for holding a lens to be processed, and an axis substantially parallel to the axis of the lens holding shaft are rotatable. And a grindstone for grinding a lens to be processed held by the lens holding shaft by a polishing surface formed on the outer peripheral surface, and moving the lens holding shaft forward and backward with respect to the whetstone to form the lens to be processed. Axial adjustment means for moving the periphery toward and away from the grindstone, contact position setting means for setting the contact position of the lens to be polished on the polished surface, and setting by the contact position setting means A lens grinding device comprising: a control unit that controls the inter-axis adjustment unit so as to move and adjust the lens holding shaft to the contact position set in the axial direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. i. First Embodiment [Apparatus Configuration] FIG. 1 shows a first embodiment of the present invention. FIG. 1 is an external perspective view showing the configuration of a lens processing apparatus (lens grinding apparatus), that is, a ball mill, according to the present invention, together with an electric circuit block diagram of a bevel processing control system.

This ball mill has a housing 10, and the housing 10 is provided with a grinding wheel chamber 11. A grinding wheel A that is rotated at a high speed by a motor (not shown) is stored in the grinding wheel chamber 11. This grinding wheel A is a rough whetstone (coarse whetstone) 12
And a beveling grindstone 13.

A bearing 14 is provided behind the housing 10, and a carriage pivot 21 is fitted into the bearing 14 so as to be rotatable and movable in the axial direction. The rear end of the carriage 20 is fixed to the carriage pivot 21.
As a result, the carriage 20 can turn around the carriage turning shaft 21 and can slide in the axial direction.

A lens holding shaft 22a, 22b disposed coaxially is held at a free end of the carriage 20, and a lens L to be processed is held between the lens holding shafts 22a, 22b. ing. This lens holding shaft 22
The axes of a and 22b and the axis of the grinding wheel 11a are provided in parallel.

The lens holding shafts 22a and 22b are rotated by a drive motor 25 arranged in the carriage 20 via a known rotation transmission mechanism Q. The template T is attached to the other end of the lens holding shaft 22b by well-known template holding means 24.
Is attached. The template T is formed in a globe shape of glasses (glasses).

On the side of the housing 10, a carriage lateral moving means A is provided. The carriage lateral moving means B includes an L-shaped arm member 30 which is slidably supported by an axial rail member 15 protruding from a side wall of the housing 10. I have. One end 34 of the arm member 30 is attached to the pivot shaft 21 of the carriage so as to be rotatable around the axis and not to move laterally.

Further, the carriage lateral moving means B includes a drive motor (Y direction drive means) 32 for lateral movement (for Y direction movement) fixed to a fixed frame (not shown), and an output shaft of the drive motor 32. Has a feed screw 33 attached thereto. The feed screw 33 is provided in parallel with the carriage turning shaft 21 and is screwed to the arm member 30. The rotation of the motor 32 causes the feed screw 3
When 3 rotates forward (forward) or reverse (reverse),
The arm member 30 moves in the left-right direction along the carriage pivot shaft 21, and the movement of the arm member 30 causes the carriage 2 to move.
0 is also moved in the same direction by the same amount.

At the other end of the arm member 30, an inter-axis distance adjusting means (inter-axis adjusting means) C is mounted. The inter-axis distance adjusting means C includes a driving motor (X-axis direction driving means, that is, a vertical direction driving means) 37 which is a pulse motor fixed to the other end of the arm member 30, It has a well-known mold cradle 38 held at the end so as to be vertically movable. The mold receiving table 38 is driven to move up and down by a vertical feed screw (not shown) interlocked with the drive motor 37. A well-known structure can be adopted for this structure. The upper surface of the mold receiving table 38, that is, the mold receiving surface 38a is configured so that the mold plate T abuts. Here, the mold receiving surface 38a has the same radius of curvature as the grinding line of the beveling grindstone 13. [Arithmetic control circuit] In addition, the ball grinding machine, which is a lens grinding device, moves and adjusts the lens holding shafts 22a and 22b in the axial direction to polish the peripheral surface of the rough grinding wheel 12 of the grinding wheel A of the lens L to be processed. There is provided a contact position setting means D for setting a contact position on the surface 12a in a direction along the axis of the grinding wheel A.

The contact position setting means (lens drop position setting means) D includes the carriage lateral moving means B described above,
It has a motor drive control circuit (drive control means) E. The motor drive control circuit E has an operation control circuit (operation control means) F. The arithmetic control circuit F includes a driver 101 for driving the drive motor 32, a control circuit 102 for controlling the operation of the driver 101 with pulses, and an arithmetic circuit 103 for controlling the operation of the control circuit 102. The motor drive control circuit E calculates the amount of movement for setting the contact position (drop position) of the lens L to be worked on the rough grindstone 12 by the arithmetic circuit 103.
And a reference y position memory 105.

The arithmetic circuit 103 includes a contact position input means 10
The shift amount yi with respect to the reference y is calculated from the movement amount for setting the contact position input in step 4 and the reference y stored in the reference y position memory 105. The control circuit 102 controls the operation of the driver 101 with a drive pulse based on the reference y and the deviation amount yi calculated by the calculation circuit 103, drives the drive motor 32, and moves the carriage 20 in the horizontal direction (Y direction). The movement is controlled.

In this embodiment, the reference y position memory 10
5, a displacement amount (moving contact position) yi (y + a) with respect to the reference y is calculated from the input movement amount a for setting the contact position of the lens L to be processed and the reference y, but this is not necessarily required. However, the present invention is not limited to this. For example, the criterion y
Without providing the position memory 105, the contact position input means 104
Is input to the polished surface 12a of the lens L to be processed.
May be a moving contact position. [Operation Panel 110] FIG. 2 shows the operation panel 11 of the ball mill.
The example of 0 is shown. The operation panel 110 includes a liquid crystal display (display device) 111 as a display unit,
A lens material selection switch 112, a frame material selection switch 113, a mode selection switch 114, a start switch 115, a finish processing switch 116, a manual processing switch 117, a stop switch 118, a-switch 119, a + switch 120, and the like are provided. ing.

The lens material selection switch 112 has an L
By selectively lighting the EDs 121a, 121b, and 121c, the material of the lens to be processed such as glass, plastic (plastic), and polycarbonate (polycarbonate) can be selected. The frame material selection switch 113 is
By selectively lighting the LEDs 122a, 122b, 122c, it is possible to select the material of the cell (cell frame), metal (metal frame), and equal glasses (glasses) frame. The mode selection switch 114
By selectively lighting the LEDs 123a and 123b, an auto mode and a manual mode can be selected.

The operation panel 110 includes a switch S
W1 and SW2 are provided as the contact position input means 104 described above. The operation panel 110 includes an LED 1 and an LE for confirming the operation of the switches SW 1 and SW 2.
D2 is provided.

Although not shown, the switches 112-1
The signal from 20 is input to the arithmetic circuit 103. Also,
The arithmetic circuit 103 controls the control circuit 10 based on signals from the switches 112 to 120 and the switches SW1 and SW2.
2 and LEDs 121a-123b and LED1, L
The lighting control of the ED2 is performed. [Operation] Hereinafter, the operation of the above-described ball mill will be described.

The lens holding end 22 of the lens holding shaft 22b
In a case where the initial position y0 of b ′ is set with reference to the left end of the rough grindstone 12, for example, the lens holding shafts 22a and 22b are moved rightward by yi from the initial position y0, and the lens holding ends of the lens holding shaft 22b are moved. The position of 22b 'is yi
, The deviation amount yi is set to a predetermined value, for example, 1.
It is set to 0 mm.

The value of the predetermined shift amount yi is set as a reference position y, and the reference position y is stored in the reference y position memory 1.
05. Further, as shown in FIG. 6A, the position of the lens holding end 22b 'of the lens holding shaft 22b, that is, the reference position y is set in advance as an absolute amount from the mechanical origin Y0, and the shift amount yi is set as shown in FIG. ) As in the machine origin Y0
May be determined on the basis of. In FIG.
Reference numerals a and 12 'denote rough grinding wheels (coarse grinding stones), 12a and 12'a denote polishing surfaces of the rough grinding stones 12 and 12', and 13 denotes a polishing surface 13 for finishing.
This is a beveled whetstone (finishing whetstone) having a.

When the switch SW1 is turned on, the moving amount a is +0.35 mm, and the switch SW2 is turned on.
A case will be described in which the movement amount a is set to be +0.70 mm.

When the reference position y is preset as an absolute amount from the mechanical origin Y0, when the switch SW1 is turned on, the movement amount of the lens holding end 22b 'of the lens holding shaft 22b is set to +0. If the distance is 35 mm, the lens holding end 22b 'of the lens holding shaft 22b is moved to, for example, a position where the value of the reference position y is 56.0 mm. Further, the displacement amount yi is set to y = 56.0 mm and the movement amount a = 0.
It is obtained as a value obtained by subtracting 65 mm, that is, 55.65 mm.

When the switch SW1 is turned on before the processing is started, LED1 is turned on (LED2 is turned off at this time), and the movement amount a = 0.35 mm is input to the arithmetic circuit 102. As a result, the arithmetic circuit 103 adds the movement amount a = 0.35 mm to the reference y = 1.0 mm stored in the reference y position memory 105 and obtains the deviation amount yi = ya
= 1.35 mm, and the deviation amount yi = ya = 1.35
mm is displayed on the liquid crystal display unit 111 of FIG.

The arithmetic circuit 103 includes a control circuit 102
The operation of the driver 101 is controlled via the
Is controlled to drive the lens holding end 22 of the lens holding shaft 22b.
b 'is moved to the position of the displacement amount yi = ya. At this position, the operation of the drive motor 37 is controlled via the arithmetic circuit 103 and the control circuit 102, and the leading end of the carriage 20 and the lens holding shafts 22a and 22b are controlled to move downward, so that the periphery of the lens L to be processed is moved. Polished surface 12a of rough whetstone 12
Can be contacted in the range of the left position 12a1.

On the other hand, when the switch SW2 is turned on before the processing is started, the LED2 is turned on (the LED1 is turned off at this time), and the movement amount a = 0.70 mm is calculated by the arithmetic circuit 102.
Is input to As a result, the arithmetic circuit 103 sets the reference y
Reference y = 1.0 mm stored in position memory 105
Is added to the movement amount a = 0.70 mm, and the deviation amount yi =
yb = 1.70 mm, and the displacement amount yi = yb = 1.
70 mm is displayed on the liquid crystal display unit 111 of FIG.

The arithmetic circuit 103 includes a control circuit 102
The operation of the driver 101 is controlled via the
Is controlled to drive the lens holding end 22 of the lens holding shaft 22b.
b 'is moved to the position of the displacement amount yi = yb. At this position, the operation of the drive motor 37 is controlled via the arithmetic circuit 103 and the control circuit 102, and the leading end of the carriage 20 and the lens holding shafts 22a and 22b are controlled to move downward, so that the periphery of the lens L to be processed is moved. Polished surface 12a of rough whetstone 12
Can be contacted in the range of the right side position 12a2.

As described above, before the processing starts, the contact position of the rough grinding stone 12 of the lens L to be processed with the polishing surface 12a, that is, the left position (left contact position) 12a1 of the polishing surface 12a and the right position (right contact) Position) 12a2 can be selected, so that local wear of a specific portion of the polished surface 12a of the rough whetstone 12 can be avoided.

After selecting the contact position of the lens L to be processed, the grindstone A is driven to rotate and the mold receiving table 38 is controlled while controlling the operation of the drive motor 37 so that the peripheral edge of the lens L to be processed is removed. The shape of the template T is ground by the rough grinding stone 12.

In the above-described embodiment, the template T is configured to be in contact with the upper surface of the mold receiving table 38, that is, the mold receiving surface 38a. However, the present invention is not limited to this. For example, the same can be performed in a lens grinding apparatus that does not use the template T (for example, see Japanese Patent Application No. 60-115079). In this case, the grinding surface 12a of the rough whetstone 12 is
1, 12a2 may be alternately contacted.

As shown in FIG. 7, fillers (lens sensors) F1 and F2 for measuring the edge thickness are brought into contact with any two points of the front refracting surface Lf and the rear refracting surface Lb of the lens L to be processed, whereby the lens L is processed. In addition to detecting the positions P1 and P2 of the edge faces W1 and W2 of the processing lens L, whether the processing lens L is a plus lens or a minus lens, and the curvature of the front refraction surface Lf and the rear refraction surface Lb of the processing lens L The degree is determined.

The positions P1 and P2 of the edge surfaces W1 and W2 are compared with a predetermined reference y position (may be based on the left end of the grindstone), and the front refracting surface Lf of the lens L to be processed is compared. In consideration of the degree of curvature of the rear refraction surface Lb and the like, the polishing surface 12a1 or 1
2a2 may be set so as to be in contact with the polishing surface 12a1, 12a2 of the rough whetstone 12 during the grinding process.
May be alternately contacted.

FIG. 3 shows that the movement amount a for setting the lens contact position is +0.80 mm and the polished surface 12 is b1
6 shows an example in which the lens L to be processed is brought into contact with the polished surface 12a of the rough grindstone 12 by dividing the lens into six pieces into b6.
By dividing the contact position finely as b1 to b6 in this way, it is possible to prevent extreme wear of a specific portion of the polished surface 12a of the rough whetstone 12.

In this embodiment, the main purpose is to prevent the abrasion of only the polished surface 12a of the rough whetstone 12. However, the present invention is not limited to this. It can also be performed on a whetstone. ii. Second Embodiment As a second embodiment, as shown in FIG. 5, in a lens grinding apparatus having a liquid crystal panel (liquid crystal display device) 130 as a display means (display device), a liquid crystal screen 1 of the liquid crystal panel 130 is used.
While displaying the image 12 'of the rough whetstone 12 on 30a,
Arrow 1 indicates the contact position selected by switches SW1 and SW2.
31 may be displayed on the liquid crystal screen 130a.

[0037]

As described above, according to the first aspect of the present invention, a lens holding shaft for holding a lens to be processed, and an axis substantially parallel to the axis of the lens holding shaft are provided so as to be rotatable. A grindstone for grinding a lens to be processed held on the lens holding shaft by a polishing surface formed on an outer peripheral surface,
Inter-axis adjusting means for moving the lens holding shaft forward and backward with respect to the grindstone to move the periphery of the lens to be processed closer to and away from the grindstone, and working on a contact position of the lens to be processed with the polishing surface. Contact position setting means set by the designation of the person, and control means for controlling the inter-axis adjustment means to move and adjust the lens holding shaft to the contact position set by the contact position setting means in the axial direction. With such a configuration, it is possible to reduce abrasion at a specific portion of the polished surface of the grinding wheel, thereby improving the working efficiency of the grinding wheel. In addition, since the lens to be processed can be machined while taking into account the amount of wear on the polished surface of the grindstone, the lens to be machined can be shaped even if the contact position of the lens to be polished on the polished surface is adjusted. (Ed) It is possible to perform accurate grinding based on shape data.

In addition, even a novice in the processing technology of the lens to be processed does not require skilled polishing skills and has the effect of not lowering the working efficiency.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a lens grinding device according to the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a lens to be processed and a grinding wheel in FIG. 1;

FIG. 3 is an explanatory view showing another example of a contact position with a grinding wheel.

FIG. 4 is an explanatory diagram showing an example of an operation panel of the lens grinding device shown in FIG.

FIG. 5 is a persuasive name diagram showing an example in which an image is displayed on a display unit using a liquid crystal panel.

FIG. 6 is an operation explanatory view of the lens grinding device of the present invention.

FIG. 7 is an operation explanatory view of the lens grinding device of the present invention.

FIG. 8 is an operation explanatory view of a conventional lens grinding device.

[Explanation of symbols]

 12: rough whetstone 12a: polishing surface 22a, 22b: lens holding shaft A: grinding whetstone C: inter-axis adjustment means D: contact position adjustment means F: arithmetic control means L: lens to be processed

Claims (1)

[Claims] 1. A lens holding shaft for holding a lens to be processed, and a lens holding shaft provided rotatably about an axis substantially parallel to the axis of the lens holding shaft, and a polished surface formed on an outer peripheral surface. A grindstone that grinds the lens to be processed held by the shaft adjusting means for moving the lens holding shaft forward and backward with respect to the grindstone to move the periphery of the lens to be processed toward and away from the grindstone; Contact position setting means for setting a contact position of the lens to be polished on the polished surface according to an operator's designation; and moving and adjusting the lens holding shaft in the axial direction to the contact position set by the contact position setting means. And a control means for controlling the inter-axis adjusting means.