Lens holding device

Abstract

To provide a lens holding device having high holding accuracy of a lens at the time of centering of an optical lens and grinding an outer shape of the optical lens into an irregular shape.SOLUTION: Provided is a lens holding device used for centering a lens. The lens holding device has a pair of a first support device and a second support device arranged so as to face each other for holding the lens therebetween. Rotation drive transmission of the first support device is controlled by a first drive part and a first belt, and rotation drive transmission of the second support device is controlled by a second drive part and a second belt.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lens holding device used in the centering process of an optical lens.

Background Art

[0002] In the centering process of an optical lens, the lens is sandwiched and rotated by a pair of opposed holders called a bell holder, a cup holder, etc., to perform centering. After that, not only circular grinding but also grinding is performed on the outer shape of the lens into various irregular shapes such as D-cut, I-cut, and square machining using a rotary grinding wheel. Here, when grinding the outer shape of the lens into an irregular shape with a grinding wheel, it is necessary not only to hold the lens with a first support device and a second support device but also to perform fixed control at a predetermined angle.

[0003] Conventionally, for example, as shown in Patent Document 1, a pair of upper and lower lens support devices for sandwiching a lens have been rotationally controlled by gear drive. In such a gear drive transmission, there is always a predetermined backlash, so there is a problem of low positioning accuracy when grinding the lens into an irregular shape. In addition, in gear drive, there is also a problem that vibration is likely to occur when the rotation speed is increased.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a lens holding device having high holding accuracy of a lens during centering processing of an optical lens and grinding of the outer shape into an irregular shape, and excellent quality of the grinding surface.

Means for Solving the Problems

[0006] The lens holding device according to the present invention is a lens holding device for use in centering a lens, and has a pair of first support devices and second support devices arranged opposite to each other for sandwiching the lens. The first support device is rotationally driven and transmitted and controlled by a first drive unit and a first belt, and the second support device is rotationally driven and transmitted and controlled by a second drive unit and a second belt.

[0007] Here, the first support device and the second support device each have a cup-shaped holder that is rotationally and fixedly controlled, and sandwich the lens from both sides. Therefore, the first support device and the second support device are controlled to move in the relatively approaching direction and the separating direction. At that time, one of the first support device and the second support device may be fixed, but at least one of them is controlled to move closer and farther in conjunction with or integrally with the drive unit with the belt stretched.

[0008] In the present invention, it is preferable that the first support device and the second support device are synchronously controlled by a computer numerical control (CNC) device. This is because in the present invention, drive units such as motors are provided for each of the first support device and the second support device.

Effect of the Invention

[0009] In the present invention, since the first support device and the second support device that sandwich and hold the lens are rotationally and fixedly controlled by belt drive, the rotation speed can be made faster than gear drive during centering of the lens, and the backlash is smaller and the positioning accuracy is higher compared to gears when fixing and supporting the lens. As a result, there are also the following effects during grinding of the lens. In the field of optical lenses, a black layer such as black painting may be formed on the back surface of the lens for the purpose of antireflection or the like. In such a case, if the quality of the grinding surface is poor, white dot-like defects may occur. In the present invention, since the vibration is small due to belt drive, there are few defects on the ground surface, and the occurrence of white spot defects can be suppressed. In addition, since the vibration is small, there is an effect of suppressing the occurrence of chipping at the grinding corner.

Brief Description of the Drawings

[0010]

Figure 1

Embodiments for Carrying Out the Invention

[0011] A structural example of the lens holding device according to the present invention will be described below with reference to the drawings. The present invention is characterized in that a belt drive system is used as means for sandwiching a lens and performing rotation control and positioning and fixing control. Other than that, design changes can be made as appropriate.

[0012] FIG. 1 schematically shows the configuration of the lens holding device. This embodiment is an example in which the first support device 10 and the second support device 20 are arranged to face each other vertically, but they may be arranged to face each other on the same axis line, and may also be in the horizontal direction.

[0013] The first support device 10 has a first spindle 11 having a cup-shaped lens holder 11a on the lower end side (tip end side), and the first spindle 11 is rotatably held on the inner peripheral side of the first spindle holder 12. On the inner peripheral side of the upper end of the first spindle holder 12, a first driven pulley 13 is attached via a first bearing 14, and the upper end side of the first spindle is detachably attached to the inner peripheral side of the first driven pulley 13 by a first connecting member. Here, there is no limitation on the connection and fixing structure between the first spindle 11 and the first driven pulley 13.

[0014] What is characteristic in the present invention is that a belt drive system in which a first belt 18 is stretched between the driven first pulley 13 and a first drive pulley 17 connected to the shaft of a first drive unit 16 such as a motor. In this embodiment, the first spindle holder 12 and the first drive unit 16 are integrally or interlocked and controlled to move up and down.

[0015] The lens 1 is sandwiched between the first lens holder 11a of the first support device 10 and the second lens holder 21a of the second support device 20. In this embodiment, the second support device 20 is arranged opposite to the first support device 10 in the vertical direction. Since the symbols in the 10s are correspondingly displayed as the symbols in the 20s with respect to the first as the second, detailed description is omitted.

[0016] Although illustration is omitted in the centering process of the optical lens, grinding is performed on the lens by a rotationally controlled grinding wheel to perform true circularity processing and grinding on various non-circular lenses such as D-cut, I-cut, and square-shaped lenses of the outer shape.

Description of Symbols

[0017] 1 Lens 10 First support device 11 First spindle 11a First lens holder 12 First spindle holder 13 First driven pulley 14 First bearing 15 First connecting member 16 First drive unit 17 First drive pulley 18 First belt 20 Second support device 21 Second spindle 21a Second lens holder 22 Second spindle holder 23 Second driven pulley 24 Second bearing 25 Second connecting member 26 Second drive unit 27 Second drive pulley 28 Second belt

Claims

1. A lens holding device for use in centering a lens, comprising: a pair of first and second support devices arranged opposite to each other for sandwiching the lens; the first support device is rotationally driven and transmitted and controlled by a first drive unit and a first belt; the second support device is rotationally driven and transmitted and controlled by a second drive unit and a second belt. A lens holding device characterized by this.

2. The lens holding device according to claim 1, wherein the first support device and the second support device are synchronously controlled by a computer numerical control (CNC) device.

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