Cutting machine for pits on CD master
AssigneeIndustrial Technology Research Institute
InventorsJia-Ming Shyu, Kuoan Huang, Jung-Lung Liu
Life of this patent
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Abstract
A cutting machine for cutting pits on a laser disc master comprising a disc signal source with a RAM and a series of shift registers; a machine unit having a servo-rotary shaft for mounting a master disc; a servo-horizontally moving shaft perpendicular to the rotary shaft; a deviation sensor mounted on the horizontally moving shaft perpendicular to the master disc; and a diamond cutting tool controlled by a signal-source-controlled piezoelectric driver. It also comprises a computer unit, which includes a disc signal control interface, and machine unit control interfaces. The rotation error of the machine unit can modulate the signal output speed of the signal source.
Claims3
A machine for cutting pits on a compact disc master comprising:
- a disc signal source for generating an adjustable signal corresponding with a length and space of the pits to be cut;
- a machine unit including:
- a rotary shaft having an axis,
- a working table for mounting a master disc perpendicular to said axis,
- a motor,
- a rpm sensor,
- a first servo-control circuit, said first servo-control circuit operating with said rpm sensor and said motor for servo-driving said rotary shaft,
- a horizontally moving shaft having a sliding block supported perpendicular to said axis to move horizontally,
- a linear actuating means controlled by a second servo-control circuit with a displacement sensor for servo-driving said horizontally moving shaft,
- a piezoelectric crystal mounted on said sliding block, perpendicular to said master disc, able to have corresponding extension and contraction motions in an axial direction,
- a cutting tool fixedly mounted on a moving end of said piezoelectric crystal, said cutting tool having a suitable blade so as to cut or lift above said master disc in accordance with said motion of said piezoelectric crystal,
- distance deviation sensor means for sensing a position error of said piezoelectric crystal along said axial direction, said distance deviation sensor means having a sensing head perpendicular to said master disc and being fixedly mounted on said sliding block close to said cutting tool to sense a distance deviation of said cutting tool to said master disc, converting said deviation into an electric signal, and
- distance setting means, responsive to said distance deviation sensor means and said adjustable signal from said disc signal source, for extending or contracting said piezoelectric crystal along said axial direction;
- and
- a computer unit including:
- signal control interface means electrically connected to said disc signal source for adjusting said adjustable signal from said disc signal source,
- first servo-control interface means for controlling said first servo-control circuit, and
- second servo-control interface means for controlling said second servo-control circuit.
Dependencies are inferred from the claim text.