Patent ID: 8241091

Claim:
An eyeglass lens processing apparatus comprising: a lens rotation unit including a motor for rotating a lens chuck shaft for holding a lens; a processing tool rotation unit including a motor for rotating a processing tool rotation shaft to which a roughing tool for rough-processing a periphery of the lens is attached; an axis-to-axis distance changing unit including a motor for changing an axis-to-axis distance between the lens chuck shaft and the processing tool rotation shaft; a lens surface configuration acquiring unit which acquires front and rear surface curve configurations of the lens by measurement or input; a lens outer diameter acquiring unit which acquires, by measurement or inputting, an outer diameter of the lens before subjected to the processing; a calculation unit which calculates, for every rotation angle of the lens, a thickness of the lens, which changes in accordance with a distance from a rotation center of the lens, based on the front and rear surface curve configurations, and calculates a cutting depth of the lens for every predetermined rotation angle of the lens, so that torque applied onto the chuck shaft in the rough-processing becomes substantially constant, based on the calculated lens thickness and a processing distance from the rotation center for every predetermined rotation angle of the lens; and a control unit which controls the axis-to-axis distance changing unit in accordance with the calculated cutting depth to perform rough-processing based on input target lens shape data.