JPH072300B2 - Lens processing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lens processing method.

[Conventional technology]

Conventional lens grinding processing includes generation grinding of optical functional surfaces (hereinafter referred to as CG processing) and peripheral side surface grinding processing and chamfering grinding processing performed after the CG processing. Conventionally, CG processing and peripheral side surface grinding are performed. It is general that the processing and the like are performed individually in separate steps. As conventional examples of performing these processing methods simultaneously or continuously, for example, Japanese Utility Model Publication No. 51-47669 (conventional example 1), Japanese Patent Application Laid-Open No. 62-152664 (conventional example 2), and Japanese Patent Application Laid-Open No. 59-192449. As disclosed in Japanese Laid-Open Patent Publication (Prior Art 3) and the like, there is known.

The lens processing methods of Conventional Example 1 and Conventional Example 2 perform chamfering grinding processing in addition to CG processing.

On the other hand, the lens grinder of Conventional Example 3 performs peripheral side surface grinding in addition to CG processing, and in addition to the CG grindstone, a peripheral side surface grinding grindstone is provided on the lens outer periphery so as to be able to come into contact with and separate from the lens outer circumference.

However, the above-mentioned three conventional examples propose processing methods in which CG processing and chamfering grinding processing, or CG processing and peripheral side surface grinding processing are performed simultaneously or continuously.

[Problems to be Solved by the Invention]

However, the peripheral side surface grinding process found in JP-A-59-192449 (Conventional Example 3) must be performed simultaneously or continuously with the CG process on either the first surface side or the second surface side. Will be completed by. In other words, it means that the entire outer peripheral portion of the lens or the chamfered portions on both sides of the entire outer peripheral portion are processed by one grinding process.

According to this method, for example, in chucking which is generally widely used as a lens holding means, the lens is held by using the lens peripheral side surface portion. Therefore, in the above processing, the lens holding member and the peripheral side surface grinding grindstone are used. Will interfere with each other and will be impossible to implement. Therefore, it is necessary to use a spherical surface holding method such as a sticking method as the lens holding means, but these are more complicated than the above chucking and are not sufficient from the viewpoint of reducing the number of steps.

The present invention has been made in view of the above-mentioned conventional problems, and simultaneously performs the lens CG processing and the peripheral side surface portion and the chamfered portion grinding processing in two divisions of the first surface side and the second surface side. In view of the above, it is an object of the present invention to provide a lens processing method capable of reducing the cost of a lens by shortening the processing process regardless of which lens holding means.

[Means and Actions for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a rotatable work spindle unit having a mechanism for holding a lens that is a work piece at a shaft tip, and a CG grindstone is detachably provided at a shaft tip, A CG tool spindle unit that is rotatable and can be moved relatively close to and away from the work spindle tip, and a centering grindstone is detachably provided on the shaft outer peripheral portion, and is rotatable, and the grindstone grinding portion is relative to the work spindle tip. In a lens processing system that consists of a centering tool spindle unit that can be moved closer to and away from the work spindle, rotate the lens attached to the tip of the work spindle to bring the work spindle and the CG tool spindle relatively close to each other The CG processing on the first surface side is performed, and at the same time as this CG processing, the centering grindstone is brought into contact with the lens and the peripheral side surface on the first surface side , And after chamfering the chamfered portion, the spherical surface portion and the peripheral side surface portion, which have already been machined, are made into a collision (a reference position for positioning: a collision), and the lens optical axis and the workpiece rotation axis The CG processing on the second surface side is performed so as to match the CG processing, and at the same time as this CG processing, the centering grindstone is brought into contact with the lens and the peripheral side surface portion on the second surface side left uncut during the processing on the first surface side. And grinding the chamfered portion.

〔Example〕

(First Embodiment) FIG. 1 is a schematic view of a lens processing system for explaining a first embodiment of the present invention. FIG. 2A shows the first surface side processing, and FIG. 2B shows the second surface. The state of side processing is shown respectively.

In FIG. 1, the lens processing system includes a work spindle unit 1, a CG tool spindle unit 2,
It is roughly composed of a centering tool spindle unit 3.

The work spindle 4 of the work spindle unit 1 is provided with a lens holder 6 that detachably holds the lens 5 at the tip of the shaft. The work spindle 4 is rotatably provided in the direction of arrow A (around the axis), and is supported by the work spindle support 7 so as to be movable in the direction of the arrow B (axial direction).

CG tool spindle 8 of CG tool spindle unit 2
An optical function surface grinding wheel 9 for grinding the optical function surface of the lens 5 is detachably attached to the shaft end of the lens.
Further, the CG tool spindle 8 is rotatably provided in the direction of arrow C (around the axis), and the axis line of the work spindle 4 (coincident with the optical axis of the lens 5) and the axis line of the CG tool spindle 8 are always It is movably supported by the CG tool spindle support 10 so as to be in the same plane. That is, the CG tool spindle 8 is swingable in the direction of arrow D with the center of the lens 5 as the swing center in a plane including the axis of the work spindle 4 (in the horizontal plane in FIG. 1). It is provided so as to be linearly movable in the direction of arrow E which is a direction perpendicular to.

In addition, the grindstone 9 for optically functional surface grinding has a creation edge diameter increased by about 20 to 30% of the radius of the lens 5.

As shown in FIGS. 1 and 2, the centering tool spindle 12 of the centering tool spindle unit 3 has a disc-shaped outer peripheral grinding wheel 13 for grinding the outer peripheral portion of the lens 5 on the outer peripheral portion of the shaft. Is detachably attached. Further, the centering tool spindle 12 is rotatably provided in the direction of the arrow (around the axis), is parallel to the optical axis of the lens 5, and is in the direction of the arrow (axial direction) and the direction of the arrow C. It is provided so as to be movable in the radial direction of the lens 5, which is the vertical direction in this embodiment.

FIG. 2a shows the processing state on the first surface side.

The centering grindstone 13 includes a peripheral side surface grindstone 13a for grinding the peripheral side surface part 5a on the first surface side of the lens 5 and a chamfering grindstone 13b for grinding the chamfering part 5b.

In order to process the lens 5 with the lens grinder provided with the centering grindstone 13 having such a structure, first, the work spindle 4, the CG tool spindle 8 and the centering tool spindle 12 are rotated, respectively, and the work spindle 4 is rotated. Is moved in the axial direction to bring the lens 5 into contact with the grindstone 9 for optically functional surface grinding, and the centering tool spindle 12 is moved to move the peripheral side grindstone 13a of the centering grindstone 13 and the chamfering grindstone 13b to the lens. 5, the peripheral side surface portion 5a and the chamfered portion 5
abut b. And the cutting speed is 1-6mm
/ min, the optical function surface 5c, the peripheral side surface 5a and the chamfered portion 5b of the lens 5 are ground (CG processing and centering processing).

After that, when the predetermined cutting amount is completed, spark-out grinding is started. After the spark-out grinding is completed, the work spindle 4 is moved backward in the axial direction to separate the lens 5 from the grindstone 9 for optically functional surface grinding, and the centering tool spindle 12 is moved to separate the centering grindstone 13 from the lens 5. Then, the first side processing is completed.

FIG. 2b shows the second surface side processed state.

The lens 5 is held by the chuck claw 6a and the abutment ring 6b, which are lens holders, with the already processed peripheral side surface portion 5a and the spherical surface portion 5c of the lens 5 that has been processed on the first surface side facing each other. The holder is made with high accuracy so that the optical axis of the chucked lens and the workpiece rotation axis coincide with each other.

The centering grindstone 14 includes a peripheral side surface grindstone 14d for grinding the peripheral side surface part 5d on the second surface side of the lens 5 and a chamfering grindstone 14e for grinding the chamfered part 5e.

In the following, the peripheral side surface 5d on the second surface side, the chamfered portion 5e, and the spherical surface portion 5f are processed by the same procedure as the processing on the first surface side.

As described above, according to this embodiment, it is possible to grind a lens with a high core accuracy without increasing the processing steps and unnecessary man-hours even by the holding method using a chuck that uses the outer circumference.

In FIG. 3, the tip shape of the centering grindstone used for each of the first surface side and the second surface side is provided on the front surface and the back surface of one grindstone. In the figure, 15a is the peripheral side grindstone 13a, 15b is the chamfering grindstone, and 15d is the peripheral side grindstone 14d.
Further, 15e corresponds to the chamfering grindstone 14e, respectively. With the grindstone having such a structure, only one grindstone is required for each lens component, which is effective in terms of cost and management.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention. This shows a method of processing a lens having a step on the peripheral side surface.

The processing means is generally the same as that in the first embodiment, and will be described briefly.

First, as shown in FIG. 4a, the first surface side is processed.
That is, the spherical portion 5c is ground by a CG grindstone (not shown), and at the same time as the grinding, the peripheral side grindstone of the centering grindstone 13 is ground.
The portion 13a and the flat centering grindstone 13b are brought into contact with the peripheral side surface portions 5a and 5b on the first surface side, and the cutting speeds 1 to 6 (mm / mi
In n), as shown in FIG. 5, grinding is performed in the intermediate direction between the grindstone axis direction and the direction perpendicular to the grindstone axis.

Next, as shown in FIG. 4B, the second surface side is processed. That is, the spherical surface portion 5f is ground by a CG grindstone (not shown), and at the same time, the peripheral side surface grindstone 14d of the centering grindstone 14 and the stepped grindstone 14g allow the peripheral side surface 5d on the second surface side to be ground.
And the stepped portion 5g is ground.

As described above, the spherical surface portion, the peripheral side surface portion, the step taper portion, and the chamfered portion of the lens having the step can be ground.

If the lens having the peripheral side surface portion having a complicated shape as in this embodiment is tried to be subjected to the peripheral side surface grinding processing and the chamfering portion grinding processing only once, the cutting edge shape of the centering grindstone is considerably complicated. Therefore, the compatibility with other parts is poor. Further, with a grindstone having such a cutting edge shape, the cutting method is limited to only the direction perpendicular to the grindstone axis, and according to such a processing method, the a-part and the locus shown in FIG. There is a high possibility that a part will be chipped.

According to the present embodiment, the above-mentioned problems are divided into two parts and processed, so that the tip shape of the grindstone becomes a simple one composed of a flat surface portion and a taper portion, and is compatible with other parts. Since it has the property of being capable of grinding in the cutting direction, it is possible to perform processing without the problem of chipping.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention. The present embodiment relates to a centering grindstone used in the method of the present invention. The centering grindstone 13 is composed of a circular plate body, and has grindstone portions 13a, 13d used for grinding the peripheral side surface of the circular plate body and grindstone portions 13b, 13e used for chamfering grinding process, and the grindstone shaft has In contrast, it has a symmetrical shape with respect to a plane cut in the vertical direction. An example of lens processing using the present grindstone is shown below.

In FIG. 6a, the lens first surface side processing is performed.

The lens 5 is provided with a edging portion 15 in order to increase the width of the peripheral side surface portion on the convex side, and the lens 5 has a peripheral side surface portion of the edging portion 15 and a convex portion side outer peripheral flat surface portion for holding the lens. It is held by a chuck claw 6a, which is a tool, and an abutment ring 6b.

Then, in this state, the spherical portion 5c is ground by the CG grindstone 9, and at the same time, by the peripheral side surface grindstone portion 13a and the chamfering grindstone portion 13b of the centering grindstone 13, the peripheral side surface portion 5a on the first surface side.
And the chamfered portion 5b is ground.

Next, as shown in FIG. 6B, the lens second surface side processing is performed. The lens 5 holds the lens 5 with the lens holders 6a and 6b by using the peripheral side surface portion 5a and the spherical surface portion 5c which are ground in the first surface side processing, and the spherical surface portion 5f is ground by the CG grindstone 9. To process. In this CG processing, the lens edge portion 15 left in the first surface side processing is removed, and since it is not necessary to chamfer the second surface side of the lens, the second surface
In the face side processing, the peripheral side surface portion and the chamfered portion are not ground.

As in the present embodiment, in the lens in which the peripheral side surface portion and the outer peripheral portion are ground during the first surface side processing, if the front and back sides of the centering grindstone have the same shape, It is also possible to turn the centering whetstone 13 over and perform the above-mentioned processing using the whetstone portions 13d and 13e, and the effect of doubling the life of the whetstone can be obtained.

〔The invention's effect〕

As described above, according to the lens processing method of the present invention, regardless of the lens holding method, it is possible to perform the CG processing and the peripheral side surface and the chamfered portion grinding processing at the same time, and the lens with good centering accuracy is processed at low cost. I was able to do it.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a schematic view, FIGS. 2 (a) and 2 (b) are explanatory views of the first embodiment, and FIG. 3 shows another embodiment of a centering grindstone. Side view, FIG. 4 (a),
FIG. 6B is an explanatory diagram of the second embodiment, FIG. 5 is an explanatory diagram showing the relationship between the lens and the grindstone, and FIGS. 6A and 6B are explanatory diagrams of the third embodiment. 1 …… Work spindle unit 2 …… CG tool spindle unit 3 …… Centering tool spindle unit 4 …… Work spindle 5 …… Lens 6 …… Lens holder 7 …… Work spindle support 8 …… CG tool spindle 9 …… Grinding wheel 10 …… CG tool spindle support 12 …… Centering tool spindle 13 …… Centering wheel

Claims (1)

[Claims] 1. A rotatable work spindle unit having a mechanism for holding a lens, which is a workpiece, at the tip of a shaft, and a grinding stone for spherical surface creation of the lens, which is detachably provided at the tip of the shaft, for rotation. A CG tool spindle unit that can freely move relative to the tip of the work spindle and a peripheral surface of the lens and a grinding wheel (chamfering grinding wheel) for grinding the chamfered portion on the outer circumference of the shaft. , A lens processing device having a centering tool spindle unit in which a grindstone grinding part is capable of moving closer to and away from the work spindle tip end part is used to create an optical functional surface of the lens, which is performed by the spherical surface creating grinding grindstone. The grinding process and the grinding process of the peripheral side surface on the CG processing surface side and the chamfering part performed by the centering grindstone at the same time are performed on the lens first surface side and And a method for processing a lens, which is performed by dividing into two processings on the second surface side.