Eyeglass lens processing apparatus

An eyeglass lens processing apparatus for beveling a peripheral edge of an eyeglass lens, comprising:

• a pair of lens chuck shafts which hold the eyeglass lens;
• a V-groove beveling grindstone which simultaneously processes bevel slopes on front and rear sides of the eyeglass lens;
• a front beveling grindstone and a rear beveling grindstone which individually process the bevel slopes on the front and rear sides, respectively, wherein a width of each of a front beveling slope of the front beveling grindstone and a rear beveling slope of the rear beveling grindstone is larger than a width of each of a front beveling slope and a rear beveling slope of the V-groove beveling grindstone;
• a lens edge position detector for detecting edge positions of a front surface and a rear surface of the eyeglass lens on the basis of target lens shape data;
• a mode selector which selects one of a low curve lens processing mode and a high curve processing mode;
• a computing unit which:
• acquires, if the low curve lens processing mode is selected by the mode selector, a low curve bevel path for locating a bevel apex between the front surface and the rear surface using a predetermined computing equation on the basis of the edge positions detected by the edge position detector, thereby providing low curve beveling data for the V-groove beveling grindstone;
• and
• acquires, if the high curve lens processing mode is selected by the mode selector, a high curve bevel path for locating the bevel apex on the front surface or at a position shifted by a predetermined quantity from the front surface curve toward the rear side on the basis of the edge positions detected by the lens edge position detector, wherein if the bevel apex of the high curve bevel path is located on the front surface, the computing unit acquires first high curve beveling data for the rear beveling grindstone based on the high curve bevel path and the height data of the rear bevel slope, and if the bevel apex of the high curve bevel path is located at the position shifted by the predetermined quantity from the front surface toward the rear side, the computing unit acquires second high curve beveling data for the front and rear beveling grindstones based on the high curve bevel path and the height data of the rear bevel slope;
• and
• a beveling controller that in the low curve lens processing mode, performs beveling the peripheral edge of the eyeglass lens by the V-groove beveling grindstone on the basis of the low curve beveling data, and in the high curve lens processing mode, performs beveling the peripheral edge of the eyeglass lens by the rear surface beveling grindstone on the basis of the first high curve beveling data, or performs beveling the peripheral edge of the eyeglass lens by the front and rear beveling grindstones on the basis of the second high curve beveling data.