Wobbled pit recording method and device of optical recording medium utilizing a plurality of time different signal waveforms
AssigneeHitachi, Ltd.
InventorSeiji Yonezawa
Life of this patent
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Abstract
A method and device for recording pre-pits on an optical recording medium by projecting a modulated optical beam onto the recording medium. A formatter signal source provides an output waveform which is divided into a plurality of separate signal waveforms different in time from one another and each of the separate signal waveforms is superposed with a different carrier frequency. The superposed signals are supplied to an acoustic-optic modulator for modulating the optical beam which is projected onto the recording medium for forming pre-wobbled pre-pits thereon.
Claims10
A recording method for an optical recording medium on which a pre-pit is recorded by projecting an optical beam modulated by a pre-pit recording signal, comprising the steps of:
- dividing output waveforms from a formatter signal source into a plurality of separate signal waveforms different in time from one another;
- superposing each of the plurality of separate signal waveforms with a different carrier frequency and providing signal outputs indicative thereof;
- modulating the optical beam by the superposed signal outputs;
- and
- projecting the optical beam onto the recording medium for forming pre-wobbled pre-pits by the modulated optical beam.
A recording device for an optical recording medium comprising:
- formatter signal source means for providing an output waveform and including means for dividing the output waveform into a plurality of separate signal waveforms different in time from one another and providing outputs of the separate signals;
- driver means for superposing each of said plurality of separate signals by acoustic signal waves different in carrier frequency from one another for providing superposed signal outputs;
- acoustic-optic modulator means for modulating an optical beam by the superposed signal outputs of the driver means and providing a modulated optical beam;
- and
- means for projecting the modulated optical beam onto the optical recording medium for forming pre-wobbled pre-pits thereon.
Dependencies are inferred from the claim text.