Patent ID: 7373706

Claim:
An apparatus for generating an optical surface on an ophthalmic workpiece comprising: a chuck for chucking the ophthalmic workpiece to be processed, said chuck having a longitudinal axis, a tool spindle arrangement for rotating about an axis of tool rotation a fly cutting tool having a tool tip for cutting the workpiece; a moving system for moving one of said chuck and said tool spindle arrangement generally transverse to said longitudinal axis of said chuck; said tool spindle arrangement comprises a rotary encoder for detecting an angle of rotation of said fly cutting tool about said axis of tool rotation and thus an angular position of said tool tip relative to the ophthalmic workpiece; and wherein said chuck is operatively connected with a fast workpiece servo capable of moving said chuck over short distances at high velocities, said fast workpiece servo being controllable taking into account the given angle of rotation of said fly cutting tool so that the ophthalmic workpiece can be advanced toward and retracted from said fly cutting tool in a defined manner while the ophthalmic workpiece is being cut by said tool tip.