Diffractive imaging of groove structures on optical tape
AssigneeOracle International Corporation
InventorScott D. Wilson
Life of this patent
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Abstract
A groove-monitoring system for imaging an optical tape surface is provided. The optical tape surface includes a plurality of groove patterns embossed thereon. The groove-monitoring system includes an optical sensor, a first light source directing a first light beam onto the optical tape surface with a first angle of incidence such that the first light beam is directly reflected from the optical tape surface and imaged by the optical sensor. The groove-monitoring system also includes a second light source directing a second light beam onto the optical tape surface with a second angle of incidence such that the second light beam is diffracted from the optical tape surface and imaged by the optical sensor as a diffracted light image.
Claims20
A groove-monitoring system for imaging an optical tape surface that includes a plurality of groove patterns, the groove-monitoring system comprises:
- an optical sensor;
- a first light source providing a first light beam that is directed onto the optical tape surface with a first angle of incidence such that the first light beam is directly reflected from the optical tape surface and imaged by the optical sensor as a direct reflection image;
- and
- a second light source directing a second light beam onto the optical tape surface with a second angle of incidence such that the second light beam is diffracted from the optical tape surface and imaged by the optical sensor as a diffracted light image.
A groove-monitoring system for imaging an optical tape surface that includes a plurality of groove patterns, the groove-monitoring system comprises:
- a linear optical sensor array;
- a first light emitting diode providing a first light beam that is directed onto the optical tape surface with a first angle of incidence such that the first light beam is directly reflected from the optical tape surface and imaged by the linear optical sensor array as a direct reflection image;
- and
- a second light emitting diode directing a second light beam onto the optical tape surface with a second angle of incidence such that the second light beam is diffracted from the optical tape surface and imaged by the linear optical sensor array as a diffracted light image;
- a tape guide that holds an optical tape proximate to the first light emitting diode and the second light emitting diode such that the first light emitting diode and the second light emitting diode direct light onto the tape surface;
- and
- a tape drive subsystem for moving an optical tape in front of the first light emitting diode and the second light emitting diode, the tape drive subsystem moving the optical tape over the tape guide.
A method for imaging an optical tape surface that includes a plurality of grooves patterns, the method comprising:
- directing a first light beam onto the optical tape surface at a first angle of incidence to produce directly reflected light from the optical tape surface;
- directing a second light beam the optical tape surface at a second angle of incidence to produce diffracted light from the optical tape surface;
- imaging the directly reflected light as a direct reflection image;
- and
- imaging the diffracted light as a diffracted light image.
Dependencies are inferred from the claim text.