发明名称 Optical disk signal processing apparatus using modulated light source in a playback operation
摘要 An optical disk signal processing apparatus retains compatibility with the conventional continuous servo recording technique, and reduces the amount of noise included in a signal played back from the optical disk without the need to decrease the size of the area for recording data, resulting in a drastically increased signal-to-noise ratio. The optical disk signal processing apparatus has a light source, an optical system for leading a light beam generated by the light source, an optical device for converging the light beam output by the optical system and applying the converged beam to the rotating optical disk, a signal detecting optical system for detecting a signal reflected by the rotating disk through the optical device, and a light detecting instrument for converting light produced by the signal detecting optical system into an electrical signal and a data detecting circuit. The intensity of the beam radiated by the light source is modulated by a modulation circuit in synchronism with data detection timing so that a playback signal having an improved signal-to-noise ratio can be obtained by integrating a product of a response waveform signal generated by a light beam reflected from an information mark and a light-intensity modulating signal over a fixed period of time.
申请公布号 US6570830(B1) 申请公布日期 2003.05.27
申请号 US20000515596 申请日期 2000.02.29
申请人 HITACHI, LTD. 发明人 MAEDA TAKESHI;SUGIYAMA HISATAKA
分类号 G11B7/00;G11B7/005;G11B7/125;G11B20/14;G11B27/30;(IPC1-7):G11B5/09 主分类号 G11B7/00
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