Optical apparatus for optical information recording medium
AssigneeHitachi Maxell, Ltd.
InventorsTamotsu Iida, Hiroshi Nagate, Toshiaki Taii, Toyoyuki Nunomura, Atsuki Hirose
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Abstract
An optical apparatus for an optical information recording medium including a light source, two acoustooptical elements for modulating the light beam emitted from the light source and an objective lens for focusing the light beam emitted from the acoustooptical elements to the optical information recording medium, the acoustooptical elements being provided in an optical path extending from the light source to the objective lens arranged such that directions of travel of supersonic waves generated in the respective acoustooptical elements are crossed to each other.
Claims25
An optical apparatus for an optical information recording medium comprising:
- an optical information recording medium;
- a beam deflector arranged in an optical path extending from a light source through a light modulator to an objective lens for deflecting a modulated light beam from said light modulator when a wobbling pit is to be recorded, said beam deflector being composed of two acoustooptical elements which are arranged in such a manner that directions of travel of supersonic waves generated in said acoustooptical elements are crossed to each other;
- and
- light intensity control means for increasing an intensity of said modulated light beam exposed to said optical information recording medium in synchronism with the beam deflection when the wobbling pit is recorded.
An optical apparatus for an optical information recording medium comprising:
- a light source;
- an acoustooptical element for modulating a light beam emitted from the light source;
- and
- an objective lens for focusing the light beam emitted from the acoustooptical element to the optical information recording medium;
- two such acoustooptical elements being provided in an optical path extending from the light source to the objective lens and arranged such that directions of travel of supersonic waves generated in the respective acoustooptical elements are crossed to each other.
An optical apparatus for an optical information recording medium comprising:
- an optical disk as the optical information recording medium;
- a spindle motor for rotating said optical disk;
- an acoustooptical beam deflector arranged in an optical path extending from a light source through a light modulator to an objective lens, said acoustooptical beam deflector being composed of two acoustooptical elements which are arranged in such a manner that the directions of travel of supersonic waves generated in the acoustooptical elements are orthogonal to each other;
- and
- means for driving said acoustooptical beam deflector such that a locus of a light spot irradiated to said optical disk draws concentric circles when an optical system including the objective lens is moved at a constant speed in a radial direction of said optical disk while said optical disk is rotated.
An optical apparatus for an optical information recording medium comprising:
- an optical disk as the optical information recording medium;
- a spindle motor for rotating said optical disk;
- an acoustooptical beam deflector arranged in an optical path extending from a light source through a light modulator to an objective lens;
- means for driving said acoustooptical beam deflector by applying a saw tooth shaped driving signal thereto such that a locus of a light spot irradiated to said optical disk draws concentric circles when an optical system including the objective lens is moved at a constant speed in a radial direction of said optical disk while said optical disk is rotated, said driving means including a voltage controlled oscillator and driving amplifier, a voltage signal varying in synchronism with an encoder output of said spindle motor being applied to said voltage controlled oscillator, further and
- an input circuit which includes a memory circuit and a D/A converter, whereby a linearity of a voltage-frequency characteristic of said voltage controlled oscillator is improved by data prestored in said memory circuit.
Dependencies are inferred from the claim text.