JPH04372351A - Lens grinding method and device therefor - Google Patents

Abstract

PURPOSE:To apply a desired V-shape along the whole periphery of the edge of a lens only by selecting two optional edge positions and inputting desired V-positions. CONSTITUTION:V-apex position information divided into the desired ratio and shift quantity along the edge of a machine lens L and its whole periphery is obtained, and on the basis of this V-apex position information, the edge of the machined lens L is V-machined. In this case, an edge radial locus is to be the locus of a machined edge obtained by copy-grinding using a template shaped after the shape of a spectacle frame into which the lens L is framed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens grinding method and apparatus for grinding an uncut lens to correspond to the shape of the lens frame of an eyeglass frame in order to fit the lens into the lens frame. It is something.

0002

[Prior Art] Conventionally, in this type of lens grinding device, the thickness of the edge is determined over the entire circumference of the edge radial trajectory of the lens to be processed in accordance with the edge radial trajectory, and a desired ratio is obtained. The bevel apex position information was obtained by inputting the information.

0003

[Problems to be Solved by the Invention] However, in the conventional method and apparatus described above, the desired ratio is input to the edge thickness data of the entire circumference and the bevel apex position is determined. The operation involved repeating input operations and checking the results, which was cumbersome.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a lens grinding method and an apparatus for the same, in which the bevel ratio and the bevel position shift amount can be determined by simply inputting a desired ratio and shift amount, and which does not require any troublesome operation. be.

[0005]

[Means for Solving the Problems] Based on this object, the lens grinding method of the present invention includes a first step for obtaining bevel apex position information that divides the edge of the lens to be processed into desired ratio shift amounts over the entire circumference. and a second step of bevelling the edge based on the bevel apex position information.

Furthermore, the edge radius vector locus is given from information on the radius vector of a lens frame of a spectacle frame in which the lens is framed. Further, in the first step, the edge thickness of the lens is determined in an unprocessed state.

Furthermore, the edge radial locus is a locus of a processed edge obtained by copy grinding using a template modeled after the shape of an eyeglass frame in which the lens is framed. Also, in the first step, the edge thickness of the processed edge is determined.

Further, the lens grinding apparatus according to the present invention includes means for selecting two arbitrary edge positions corresponding to the edge radius locus of the lens to be processed, and an input for inputting the bevel apex positions of the two points. means for calculating the positional information of the bevel apex that divides the edge over its entire circumference according to the ratio and shift amount determined from the bevel apex positions of the two points; and processing control means for bevelling the edges.

Moreover, the edge radius vector locus is given from the radius vector information of the lens frame of the eyeglass frame in which the lens is framed. Further, the measuring means determines the edge thickness of the lens in an unprocessed state. Further, the edge radial locus is a locus of a processed edge obtained by copy-grinding using a template modeled after the lens frame of an eyeglass frame in which the lens is framed. Furthermore, the measuring means measures the edge thickness of the processed edge.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to FIGS. 1 to 6.

[First Embodiment] FIGS. 1 and 2 are block diagrams showing a first embodiment of the present invention.

In FIG. 1, 10 is a frame shape measuring device, and 12 is an edge thickness measuring device.

This frame shape measuring device 10 has the same structure and operation as the device described in the applicant's earlier application, ie, Japanese Patent Application No. 1987-287491. Moreover, this frame shape measuring device 10 can measure the shape of the lens frame of the eyeglass frame in which the lens L is framed using radius vector information (ρi, θi).
is measured and stored in the memory 11.

The edge thickness measuring device 12 has a structure and operation similar to that described in detail in the applicant's earlier application, ie, Japanese Patent Application No. 115079/1983. This edge thickness measuring device 12 includes a pulse motor 120, fillers 123 and 124 that come into contact with the front and rear refractive surfaces of the lens L to be processed, and encoders 121 and 122 for measuring the amount of movement of the fillers 123 and 124. , this filler 123,12
4 and encoders 121 and 122 and is moved by a pulse motor 120.

Further, the lens L is held by a lens rotation shaft 13 of a carriage C (see FIG. 2), and is driven by a pulse motor 1.
4, it can be rotated around its optical axis.

The radius ρi of the radius vector information (ρi, θi) of the lens frame stored in the memory 11 is determined by the pulse motor 120.
The pulse motor 120 moves the support base 125 based on this input. As a result, the filler 123,
124 is arranged so that it can come into contact with the refractive surface of the raw lens L at the position of radius ρi.

On the other hand, the angle information θi is determined by the pulse motor 14.
The pulse motor 14 rotates the lens rotation shaft 13 by θi based on this input. As a result, the lens L is rotated by an angle θi. The respective movement amounts ai and bi of the fillers 123 and 124 at the radial positions (ρi, θi) (see FIGS. 3 and 4) set in this way are input to the calculation device 15.

In this calculation device 15, as shown in FIG. 3, the edge thickness Δi [i=1, 2, 3, . . .
bi …………………………………………Calculated from (1).

Then, the maximum edge thickness ΔMAX and the minimum edge thickness ΔMIN are selected from the edge thickness data ΔN.

Next, the bevel position input device 16 determines the bevel position YMAX of the maximum edge thickness ΔMAX and the minimum edge thickness ΔMIN.
, YMIN. Based on the above data, the arithmetic unit 15 calculates the bevel ratio X and the bevel shift amount c using the following formulas.

X=(YMAX-YMIN)/(ΔMAX-ΔMIN)
………(2)c=YMAX−X×ΔMAX……
………………………(3) From the above values, the bevel apex position Zi at the edge thickness Δi is determined as Zi=ai+Δi×x+c...
…………………………………(4) is obtained, and this Zi
The radius vector information ρ of the lens frame input to the calculation device 15
i, θi, that is, the bevel position information (ρi, θi, Zi) [i=1, 2, 3,...
. . .N] is output and stored in the memory 17.

By associating this Zi with the lens frame radius vector information ρi, θi, that is, the measured edge position, which is input to the arithmetic unit 15, bevel position information (ρi, θi, Zi) is obtained.
[i=1, 2, 3, . . . N] is output and stored in the memory 17.

The bevel processing of the lens L is performed by a processing apparatus shown in FIG. A carriage C holding the lens L is moved in the Z direction by a pulse motor 21 and a feed screw 21a. In addition, the lens rotation axis 13 and the grindstones G1, G2
The distance from the grinding surface to the grinding surface is controlled by moving the stopper 23 in the X direction. The movement of the stopper 23 is carried out by a pulse motor 22.
and the feed screw 22a. The detailed structure and operation of this processing device are described in the above-mentioned Japanese Patent Application No. 115079/1982.

First, from the memory 17, lens frame radius information (
Only ρi, θi) are read out by the controller 20,
This lens frame radius vector information (ρi, θi) is used by the pulse motor 1.
4 and 22. Then, put the lens L on the rough whetstone G.
1, rough grinding is performed to a shape corresponding to the radius vector information (ρi, θi).

Next, the controller 20 reads the bevel apex information (ρi, θi, Zi) from the memory 17, inputs the angle information θi to the pulse motor 14, inputs the radius information ρi to the pulse motor 22, Pulse motor 21
The Z-direction information Zi is inputted to each of the positions, and the bevel y is set on the lens L using the V-groove grindstone G2 (see FIG. 5).

As a result, as shown in FIG. 5, a bevel y is formed over the entire edge of the lens such that the apex of the bevel is located at the desired bevel position Δi×X+c.

[Second Embodiment] The edge thickness measuring device 12 of the first embodiment described above is capable of measuring the edge thickness Δi corresponding to the lens frame shape when the lens L is unprocessed (before rough grinding). However, the present invention is not limited to this, and as shown in FIG. 6, the edge thickness Δi of the lens after rough grinding is
may be measured.

In FIG. 6, the edge thickness measuring device 30 includes truncated conical pieces 32 and 33 inserted through a rod 31 that contacts the edge of the lens, and encoders 34 and 35 that measure the amount of movement of the pieces 32 and 33. etc. This frame 3
The edge thickness Δi is obtained by sandwiching the edges of the lens L after rough grinding between the shoulders 32a and 33a of No. 2 and 33. The structure and operation of this edge thickness measuring device 30 are detailed in Japanese Patent Application No. 58-225198 previously filed by the present applicant.

Furthermore, the grinding of the lens L does not need to be done by a direct grinding method based on pre-measured radius vector information of the lens frame, but instead of grinding the lens L using a grinding method that is performed based on pre-measured radial information of the lens frame. It may also be done by a copying method using a template made after the shape.

When using this copying method, the template T is attached to the end of the lens rotation shaft 13 of the carriage C as added on the left side of FIG. Fix it at the height. Moreover, the bevel apex position information is combined with the angle information θi of the lens rotation axis (Zi,
θi).

[0031]

[Effect] As explained above, according to the present invention, a desired bevel can be applied to the entire circumference of the lens edge by simply selecting two arbitrary edge positions and inputting the desired bevel position. This eliminates the hassle of operation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an edge thickness measuring device portion of a lens grinding device according to the present invention.

FIG. 2 is a block diagram simultaneously showing a first and second embodiment of a beveling device portion of a lens grinding device of the present invention.

FIG. 3 is a schematic diagram showing the relationship between edge thickness and bevel apex position.

FIG. 4 is a schematic diagram showing the relationship between the lens vector radius and the lens.

FIG. 5 is a side view showing the lens after beveling.

FIG. 6 is an explanatory diagram showing a second embodiment of the edge thickness measuring portion of the lens grinding device of the present invention.

[Explanation of symbols]

L...Lens 10...Frame shape measuring device 12, 30...Edge thickness measuring device 14, 21, 22...Pulse motor 15...Arithmetic device 16...Bevel position input device 20...Controller

Claims (10)

[Claims] 1. A first step of obtaining bevel apex position information that divides the edge of the lens to be processed into desired ratios and shift amounts over the entire circumference, and beveling the edge based on the bevel apex position information. A lens grinding method comprising a second step of: 2. The lens grinding method according to claim 1, wherein the edge radius trajectory is given from radius radius information of a lens frame of an eyeglass frame in which the lens is framed. 3. The lens grinding method according to claim 2, wherein in the first step, the edge thickness is determined while the lens is in an unprocessed state. 4. The edge radial locus is a locus of a processed edge obtained by copy grinding using a template modeled after the shape of an eyeglass frame in which the lens is inserted. The lens grinding method according to claim 1. 5. The lens grinding method according to claim 4, wherein the first step includes determining the edge thickness of the processed edge. 6. Means for selecting two arbitrary edge positions corresponding to the edge radius locus of the lens to be processed; input means for inputting bevel apex positions of the two points; and input means for inputting the bevel apex positions of the two points. calculation means for determining position information of a bevel apex that divides the edge over its entire circumference according to a ratio and shift amount determined from the position; and processing control means for beveling the edge based on the bevel apex position information. A lens grinding device characterized by having: 7. The lens grinding device according to claim 6, wherein the edge radius vector locus is given from radius vector information of a lens frame of an eyeglass frame in which the lens is framed. 8. The measuring means determines the edge thickness of the lens in an unprocessed state.
The lens grinding device described in . 9. The edge radial locus is a locus of a processed edge obtained by copy grinding using a template modeled after the lens frame of an eyeglass frame in which the lens is inserted. The lens grinding device according to claim 8. 10. The lens grinding apparatus according to claim 9, wherein the measuring means measures the edge thickness of the processed edge.