EYEGLASS LENS PROCESSING APPARATUS

• US 20130203322A1
• Filed: 02/01/2013
• Published: 08/08/2013
• Est. Priority Date: 02/03/2012
• Status: Active Grant

• Current Assignee: Nidek Company Limited
• Original Assignee: Nidek Company Limited
• Inventors: SHIBATA, Ryoji, TANABE, Osamu
• Granted Patent: US 9,604,342 B2
• Time in Patent Office: Days
• US Class Current: 451/5
• CPC Class Codes: B24B 49/006 taking regard of the speed
• CPC Class Codes: B24B 49/16 taking regard of the load
• CPC Class Codes: B24B 9/148 electrically, e.g. numerically, controlled

Abstract

In an eyeglass lens processing apparatus, a roughing tool for roughing a periphery of an eyeglass lens cuts the periphery up to a roughing path without rotating an eyeglass lens in a first stage and the roughing tool moves along the roughing path while rotating the eyeglass lens in a second stage. A calculating unit for obtaining control data of the lens rotating unit at the second stage. The calculating unit obtains a first load torque applied to a lens chuck shaft at every rotation angle of the lens based on condition data, and obtains a rotation speed of the lens at which the first load torque per unit time becomes equal to or lower than a predetermined reference value.

Claims

1. An eyeglass lens processing apparatus for processing a periphery of an eyeglass lens, the eyeglass lens processing apparatus comprising:

a lens rotating unit configured to rotate a lens chuck shaft for holding the eyeglass lens;

a tool rotating unit configured to rotate a tool spindle to which a roughing tool for roughing the periphery of the eyeglass lens is attached;

a moving unit configured to move the lens chuck shaft relative to the tool spindle;

a controller configured to control the lens rotating unit and the moving unit based on a roughing path for roughing the periphery the periphery of the eyeglass lens by the roughing tool, such that the roughing tool cuts the periphery of the eyeglass lens up to the roughing path without rotating the eyeglass lens in a first stage and the roughing tool moves along the roughing path while rotating the eyeglass lens in a second stage; and

a calculating unit configured to calculate control data of the lens rotating unit at the second stage,

wherein the calculating unit obtains a first load torque applied to the lens chuck shaft at every rotation angle of the lens based on condition data including the roughing path, thickness at a radial position of the lens around a chuck center of the lens chuck shaft and a diameter of the roughing tool, and obtains a rotation speed of the lens at which the first load torque per unit time becomes equal to or lower than a reference value.

2. The eyeglass lens processing apparatus according to claim 1, wherein the calculating unit divides a processing region at every rotation angle of the lens into small regions by a predetermined calculation method, obtains a second load torque at every small region based on the condition data, and obtains the first load torque at every rotation angle of the lens by integrating the obtained second load torque.

3. The eyeglass lens processing apparatus according to claim 1, wherein the calculating unit obtains a processing load applied to a force point determined by a predetermined method for the processing region at every rotation angle of the lens, and a direction of the processing load based on the condition data, and obtains the first load torque based on the distance from the chuck center of the lens chuck shafts to the force point, the processing load, and the direction of the processing load.

4. The eyeglass lens processing apparatus according to claim 2, wherein the calculating unit obtains an amount of processing at every small region roughed based on the condition data, obtains a processing load that is generated by the rotation of the roughing tool based on the processing amounts, and obtains the second load torque at every small region based on the distance from the chuck center of the lens chuck shafts to the small region, the processing load.

5. The eyeglass lens processing apparatus according to claim 1, further comprising:

lens surface shape obtaining unit for obtaining a front surface shape and a rear surface shape of the lens; and

a lens external diameter obtaining unit configured to obtain an external diameter of the lens, and

wherein the calculating unit obtains the thickness at the radial position of the lens based on the front surface shape and the rear surface shape of the lens obtained by the lens surface shape obtaining unit and the external diameter of the lens obtained by the lens external diameter obtaining unit.

6. The eyeglass lens processing apparatus according to claim 5, wherein the lens external diameter obtaining unit includes a storage unit for storing an external diameter which have been set in advance.

7. The eyeglass lens processing apparatus according to claim 1 further comprising:

a load detector configured to detect a rotation load applied to the lens by the roughing tool,

wherein when the load detected by the load detector exceeds a value set in order to suppress an occurrence of axis deviation, the controller controls the rotating speed of the lens rotating unit so that the rotation load does not exceed the value.

8. The eyeglass lens processing apparatus according to claim 1,

a load detector configured to detect a rotation load applied to the lens by the roughing tool,

wherein when the load detected by the load detector exceeds a value set in order to suppress an occurrence of axis deviation, the controller corrects a rotating speed obtained by the calculating unit by a predetermined method, and controls the lens rotating unit based on the corrected rotating speed.

9. The eyeglass lens processing apparatus according to claim 1,

wherein the controller controls the lens rotating unit so as not to exceed an upper speed limit set in order to prevent damage of the lens at least in a second half of one rotation of the lens.

10. The eyeglass lens processing apparatus according to claim 1, further comprising mode selection unit for selecting a first mode when a water-repellant lens is processed and a second mode when a normal lens is processed,

wherein the reference value applied when the second mode is selected is set to be higher than that when the first mode is selected.