Lens edging system, edging size management device, edging size management method and method of manufacturing spectacle lens

Patent metadata

Field	Value
Publication number	US-9962803-B2
Application number	US-201314443482-A
Country	US
Kind code	B2
Filing date	Nov 1, 2013
Priority date	Nov 26, 2012
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A lens edging system includes: an edger configured to perform edging to a spectacle lens in accordance with three-dimensional edging locus data obtained from edging shape data by calculation; a three-dimensional circumferential length measurement device configured to measure a circumferential length of the spectacle lens edged by the edger; and an edging size management device configured to correct a calculation parameter used for calculating the edging locus data, based on a difference between a measured circumferential length obtained by a three-dimensional circumferential length measurement device, and a theoretical circumferential length obtained by calculation.

First claim

The invention claimed is:

1. A lens edging system, comprising:
a lens holder configured to secure a lens and rotate the lens about a lens axis;
an edger configured to perform edging to the lens with an edging tool for edging;

the edging tool for edging configured to rotate about a tool axis offset from the lens axis, at least one of the lens holder and the edger being configured to allow a distance between the tool axis and the lens axis to be adjustable;
a three-dimensional measurement device configured to three-dimensionally measure an actual circumferential edge length of the lens;
a controller configured to:
receive edging shape data defining a desired finish shape of the lens with a theoretical circumferential edge length, the controller configured to use the edging shape data and a calculation tool diameter of an edging tool for calculation to calculate three-dimensional edging locus data defining distances between the tool axis and the lens axis wherein the edging tool, at the calculation tool diameter, maintains tangential contact with the desired finish shape defining a plurality of points of contact around the entire theoretical circumferential edge length;
perform a first edging operation by rotating the lens about the lens axis, rotating the edging tool for edging about the tool axis and controlling the distance between the tool axis and the lens axis using the three-dimensional edging locus data,
receive a three-dimensional measurement of an actual circumferential edge length of the lens after the first edging operation,
calculate a difference between the actual circumferential edge length and the theoretical circumferential edge length,
determine a correction value based on the difference,
calculate a corrected tool diameter of the edging tool for calculation based on applying the correction value to the calculation tool diameter,
use the edging shape data to calculate corrected three-dimensional edging locus data defining corrected distances between the tool axis and the lens axis wherein the distance between the tool axis and the lens axis is adjusted based on maintaining a cutting edge of the edging tool, at the corrected tool diameter, coincident with the respective plurality of points of tangential contact around the entire theoretical circumferential edge length, and
perform another edging operation by rotating a second lens about the lens axis, rotating the edging tool about the tool axis and controlling the distance between the tool axis and the lens axis using the corrected three-dimensional edging locus data to produce a finish shape of the second lens with a corrected circumferential edge length.

2. The lens edging system according to claim 1 , further comprising a memory that stores and holds a plurality of predetermined correction values in association with (i) different spectacle lens materials and (ii) different edging tool types, wherein the controller corrects the calculation tool diameter value of the edging tool for each spectacle lens material and for each edging tool type, using the stored and held predetermined correction values.

3. The lens edging system according to claim 2 , wherein the memory is further configured to sequentially store the measured value of the circumferential length and the theoretical value of the circumferential length as edging history data, in association with a spectacle lens material of the spectacle lens and an edging tool type of the edging tool used, every time the edging is performed once;
and wherein the controller is further configured to:
extract from the memory a plurality of edging history data stored in the memory, each of the extracted plurality of edging history data being associated with the same spectacle lens material and edging tool type as that of a current edging; and
obtain an average value of the difference between the measured circumferential length and the theoretical circumferential length using the extracted plurality of edging history data, and when the obtained average value exceeds a preset defined range, change the correction value used for the current edging.

4. The lens edging system according to claim 1 , further comprising:
a memory configured to sequentially store the measured value of the circumferential length and the theoretical value of the circumferential length as edging history data, in association with a spectacle lens material of the spectacle lens and an edging tool type of the edging tool used, every time the edging is performed once;

wherein the controller is further configured to:
extract from the memory a plurality of edging history data stored in the memory, each of the extracted plurality of edging history data being associated with the same spectacle lens material and edging tool type as that of a current edging; and
obtain an average value of the difference between the measured circumferential length and the theoretical circumferential length using the extracted plurality of edging history data, and when the obtained average value exceeds a preset defined range, change the correction value used for the current edging.

5. A controller that controls a lens edging system that includes (i) a lens holder configured to secure a lens and rotate the lens about a lens axis; (ii) an edger configured to perform edging to the lens with an edging tool for edging; the edging tool for edging configured to rotate about a tool axis offset from the lens axis, at least one of the lens holder and the edger being configured to allow a distance between the tool axis and the lens axis to be adjustable; and (iii) a three-dimensional measurement device configured to three-dimensionally measure an actual circumferential edge length of the lens; the controller being configured to:
receive edging shape data defining a desired finish shape of the lens with a theoretical circumferential edge length, and use the edging shape data and a calculation tool diameter of an edging tool for calculation to calculate three-dimensional edging locus data defining distances between the tool axis and the lens axis wherein the edging tool, at the calculation tool diameter, maintains tangential contact with the desired finish shape defining a plurality of points of contact around the entire theoretical circumferential edge length;
perform a first edging operation by rotating the lens about the lens axis, rotating the edging tool for edging about the tool axis and controlling the distance between the tool axis and the lens axis using the three-dimensional edging locus data,
receive a three-dimensional measurement of an actual circumferential edge length of the lens after the first edging operation,
calculate a difference between the actual circumferential edge length and the theoretical circumferential edge length,
determine a correction value based on the difference,
calculate a corrected tool diameter of the edging tool for calculation based on applying the correction value to the calculation tool diameter,
use the edging shape data to calculate corrected three-dimensional edging locus data defining corrected distances between the tool axis and the lens axis wherein the distance between the tool axis and the lens axis is adjusted based on maintaining a cutting edge of the edging tool, at the corrected tool diameter, coincident with the respective plurality of points of tangential contact around the entire theoretical circumferential edge length, and
perform another edging operation by rotating a second lens about the lens axis, rotating the edging tool about the tool axis and controlling the distance between the tool axis and the lens axis using the corrected three-dimensional edging locus data to produce a finish shape of the second lens with a corrected circumferential edge length.

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Assignees

• Hoya Corp

Inventors

• SUZUE Takahiro
• Sato Tsukasa

Classifications

• B24B49/02

  according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent (B24B49/12 takes precedence) · CPC title

• B24B9/148 Primary

  electrically, e.g. numerically, controlled · CPC title