Surface inspection by amplitude modulated specular light detection
AssigneeSeagate Technology LLC
InventorsPeter C. Jann, Wafaa Abdalla
Life of this patent
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Abstract
An apparatus for detecting defects on a disk surface includes a light source that generates a light beam and a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion. The first light beam portion illuminates the surface of the disk and produces a reflected light beam. An acoustic-optic deflector deflects the reflected light beam and the second light beam portion producing a deflected output beam having a deflection angle. A detector detects an incident beam translation signal corresponding to reflected light beam angular deflection and acoustic-optic deflector beam angular deflection from the deflected output beam.
Claims20
An apparatus for detecting defects on a disk surface, comprising:
- a light source that generates a light beam;
- a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion, the first light beam portion illuminating the surface of the disk and produces a reflected light beam;
- an acoustic-optic deflector that deflects the reflected light beam and the second light beam portion producing a deflected output beam having a deflection angle;
- and
- a detector that detects an incident beam translation signal corresponding to reflected light beam angular deflection and acoustic-optic deflector beam angular deflection from the deflected output beam.
A method for detecting defects on a disk surface, comprising:
- generating a light beam;
- splitting the light beam into a first light beam portion and a second light beam portion, the first light beam portion illuminating the surface of the disk which produces a reflected light beam;
- deflecting the reflected light beam and the second light beam portion to produce a deflected output beam having a deflection angle;
- and
- detecting an incident beam translation signal corresponding to reflected light beam angular deflection and acoustic-optic deflector beam angular deflection from the deflected output beam.
A system for detecting defects on a disk surface, comprising:
- a light source that generates a light beam;
- a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion, the first light beam portion illuminating the surface of the disk and produces a reflected light beam;
- an acoustic-optic deflector that deflects the reflected light beam and the second light beam portion producing a deflected output beam having a deflection angle;
- a detector that detects an incident beam translation signal corresponding to reflected light beam angular deflection and acoustic-optic deflector beam angular deflection from the deflected output beam;
- and
- a processor coupled to the detector that determines the presence of a defect based on the incident beam translation signal.
Dependencies are inferred from the claim text.