Optical head and optical disk apparatus
AssigneeFuji Xerox Co., Ltd.
InventorsKiichi Ueyanagi, Kazuo Baba
Life of this patent
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Abstract
A small-sized optical head and optical disk apparatus capable of high-density recording at a high data transfer rate. A collimated light beam is incident on a first surface of a transparent condensing medium. The light beam incident on the first surface is reflected by a reflective structure, such as a metallic film or a hologram, formed on the outside of a second surface of the transparent condensing medium. The reflected light forms a beam spot on a third surface of the transparent condensing medium. Light condensed at the beam spot is emitted as near field light, and propagates to a recording medium for optical recording or reproduction.
Claims33
An optical head, comprising:
- a light emitter that emits a light beam;
- and
- a transparent condensing medium that has a first surface on which said light beam is incident, and a second surface at which a reflective structure is formed that reflects light incident on said first surface to form a beam spot on a third surface of the transparent condensing medium to record or reproduce information using near field light.
An optical disk apparatus having an optical disk which rotates and an optical head which forms a beam spot on said optical disk by condensing a light beam, to record or reproduce information using near field light, said optical head comprising:
- a light beam emitter that emits said light beam;
- and
- a transparent condensing medium having a first surface on which said light beam is incident, and a second surface, at which a reflective structure is formed that reflects light incident on said first surface to form a beam spot on a third surface of the transparent condensing medium to record or reproduce information using near field light.
An optical disk apparatus having a plurality of optical disks that are coaxially arranged, spaced apart at a predetermined interval and rotate, and a plurality of optical heads which condense light beams to form beam spots near said plurality of optical disks for recording or reproducing information using near field light, said optical heads each comprising:
- a light beam emitter that emits a light beam;
- and
- a transparent condensing medium having a first surface on which said light beam is incident, and a second surface, at which a reflective structure is formed that reflects said light beam to form a beam spot on a third surface of the transparent condensing medium for recording or reproducing information using near field light.
An optical disk apparatus, having an optical disk that rotates, and an optical head having a transparent condensing medium that has a first surface on which said light beam is incident, and a second surface at which a reflective structure is formed that reflects light incident on said first surface to form a beam spot on a third surface of the transparent condensing medium to form a beam spot on said optical disk by condensing a light beam to record or reproduce information using near field light, comprising:
- an optical head mover that moves said optical head in predetermined tracking directions;
- a semiconductor laser that emits said light beam;
- a piezoelectric element that moves said semiconductor laser to displace a position at which said beam spot is formed;
- and
- a driver that drives said optical head mover on the basis of an error signal in a low frequency area and that drives said piezoelectric element on the basis of an error signal in a high frequency area.
An optical disk apparatus that forms a beam spot near an optical disk by condensing a light beam to record or reproduce information using near field light, comprising:
- an irradiator that emits a collimated light beam;
- and
- a reflector that reflects said light beam to form said beam spot near said optical disk to record or reproduce information using near field light, wherein said reflector comprises a transparent condensing medium that has a first surface on which said light beam from said irradiator is incident and a second surface, at which a reflective structure is formed that reflects said laser beam incident on said first surface to form a beam spot on a third surface of the transparent condensing medium.
An optical head having a transparent condensing medium that has a first surface on which said light beam is incident, and a second surface at which a reflective structure is formed that reflects light incident on said first surface to form a beam spot on a third surface of the transparent condensing medium to form a beam spot near an optical disk to record or reproduce information using near field light.
Dependencies are inferred from the claim text.