US Patent 7848843 Eyeglass lens processing apparatus and lens fixing cup

In a two-step processing mode in which a cup for attaching a lens to a chuck axis is changed from a large diameter cup to a small diameter cup on the way of processing, a roughing path data computing unit for computing first roughing path data larger than the target lens shape data by a predetermined finishing margin, and second roughing path data having a radius vector larger by at least Δa than at least radius vector data of the large diameter cup; and a processing controller for roughing the peripheral edge of the lens based on the second roughing path data in response to a processing start signal, thereafter stopping the processing and further resuming the processing. The processing controller performs, when a processing resuming signal is inputted, processing control of either roughing and finishing, or finishing without roughing.