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EP0317193A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Optical disc recording system

Assignee: Yamaha Corp
•
Filing: 1988-11-11
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Granted: —
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Expires: 2008-11-11
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Abstract

Abstract An optical disc recording system can record data on a writable type optical disc and reproduce the recorded data by utilizing a playback device adapted exclusively for playing back a standardized unwritable optical disc such as a Compact Disc. The optical disc recording system comprises recording medium (1) and a recording device (2). The recording medium (1) consists of an optical disc having its recording surface made of a material which is writable with a semiconductor laser and has a relatively high rate of laser beam reflection, having a mechanical size agreeing with a standard size of an optical disc for playback only and having a pregroove of a relatively small depth. The recording device (2) comprises a data signal outputting circuit for outputting an input signal to be recorded at a predetermined transfer speed as a data signal of a mark length recording system agreeing with a standard format of the optical disc for playback only, a drive control circuit for driving the recording medium at a standard speed of the optical disc for playback only and controlling positions of the recording medium and the semiconductor laser so as to agree with a standard track pitch of the optical disc for playback only, and a laser control circuit for controlling irradiation state of the semiconductor laser in accordance with output of the data signal outputting circuit. The recording medium (1) recorded by the recording device (2) is played back by utilizing a playback device (3) for the optical disc for playback only.

Inventors

  • 👤 Seiji C/O Yamaha Corporation Matsumoto
  • 👤 Katsuichi C/O Yamaha Corporation Osakabe

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-01 22:47
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2407; G11B7/24085; G11B27/00; G11B27/02; G11B27/031; G11B27/034; G11B7/004; G11B7/0045; G11B2220/00; G11B2220/20; G11B2220/21; G11B2220/213; G11B2220/215; G11B2220/216; G11B2220/218; G11B2220/25; G11B2220/2525; G11B2220/2537; G11B2220/2545; G11B2220/255; G11B2220/2587

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 199 words
An optical disc recording system comprising: recording medium means consisting of an optical disc having its recording surface made of a material which is writable with a laser and has a relatively high rate of laser beam reflection, having a mechanical size agreeing with a standard size of an optical disc for playback only and having a pregroove of a relatively small depth; and a recording device comprising data signal outputting means for outputting an input signal to be recorded at a predetermined transfer speed as a data signal of a mark length recording system agreeing with a standard format of the optical disc for playback only, drive control means for driving said recording medium means at a standard speed of the optical disc for playback only and controlling positions of said recording medium means and said laser so as to agree with a standard track pitch of the optical disc for playback only, and laser control means for controlling irradiation state of said laser in accordance with output of said data signal outputting means, said recording medium means recorded by said recording device being played back by utilizing a playback device for the optical disc for playback only.
Claim 2
Dependent Claim 199 words
An optical disc recording system comprising: recording medium means consisting of an optical disc having its recording surface made of a material which is writable with a laser and has a relatively high rate of laser beam reflection, having a mechanical size agreeing with a standard size of an optical disc for playback only and having a pregroove of a relatively small depth; and a recording device comprising data signal outputting means for outputting an input signal to be recorded at a predetermined transfer speed as a data signal of a mark length recording system agreeing with a standard format of the optical disc for playback only, drive control means for driving said recording medium means at a standard speed of the optical disc for playback only and controlling positions of said recording medium means and said laser so as to agree with a standard track pitch of the optical disc for playback only, and laser control means for controlling irradiation state of said laser in accordance with output of said data signal outputting means, said recording medium means recorded by said recording device being played back by utilizing a playback device for the optical disc for playback only.
Claim 3
Dependent Claim 43 words
An optical disc recording system as defined in claim 1 wherein said recording device comprises data signal correction means for correcting the data signal in its waveform in accordance with pit length of its pit and immediately preceding blank length of the pit.
Claim 4
Dependent Claim 71 words
An optical disc recording system as defined in claim 2 wherein said data signal correction means reduces difference in position between data signal timing and recorded pit and blank due to a heat accumulation effect caused by laser beam irradiated on the recording surface of said recording medium means by increasing or decreasing the data signal timing and prevents increase in width of recorded pit by splitting the data signal timing.
Claim 5
Dependent Claim 113 words
An optical disc recording system as defined in claim 3 wherein said data signal correction means, for increasing and decreasing the data signal timing, shortens irradiation time of the laser beam when a pit whose immediately preceding blank length is short is formed, quickens start of irradiation of the laser beam when a pit whose immediately preceding blank length is long is formed and shortens irradiation time of the laser beam when a long pit is formed, and for splitting the data signal timing, determines split number, pulse width and pulse intensity of each split laser beam pulse so that the bit width is formed in the range of 0.3 - 0.9 µm.
Claim 6
Dependent Claim 31 words
An optical disc recording system as defined in claim 1 wherein the laser beam reflecting rate of material of said recording medium means is in the range of 59 - 75%.
Claim 7
Dependent Claim 28 words
An optical disc recording system as defined in claim 1 wherein depth of a pregroove of said recording medium means is in the range of 20 - 50nm.

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