Title:
OPTICAL DISC REPRODUCTION DEVICE AND OPTICAL DISC REPRODUCTION METHOD
Document Type and Number:
WIPO Patent Application WO/2004/036563
Kind Code:
A1
Abstract:
A bottom hold circuit generates a bottom hold signal (BH signal) from an RFDC signal of an RF amplifier and sends it to a comparator. The comparator compares a reference level to the BH signal and generates an Rfdet signal which becomes H level if the BH signal is lower than the reference level. The Rfdet signal becomes H level when the laser spot is in the data recording area of the disc and L level when the laser spot is in an unrecorded area. When a servo processing microcomputer detects that the Rfdet signal is at H level during one cycle of the disc, the servo processing microcomputer controls an optical pickup to perform tracking servo.
Inventors:
KOBAYASHI TOSHIKAZU
ENOKIHARA TAKASHI
ENOKIHARA TAKASHI
Application Number:
PCT/JP2003/010487
Publication Date:
April 29, 2004
Filing Date:
August 20, 2003
Export Citation:
Assignee:
SONY COMPUTER ENTERTAINMENT INC (JP)
International Classes:
G11B7/085; G11B27/22; G11B7/09; G11B7/095; (IPC1-7): G11B7/085
Foreign References:
| JP2001250245A | 2001-09-14 | |||
| JP2003030865A | 2003-01-31 |
Other References:
See also references of EP 1580736A4
Attorney, Agent or Firm:
Yoneyama, Hisashi (Nichiginmae Bldg. 5th Floor 3-2-3, Nihonbashi Hongokuch, Chuo-ku Tokyo, JP)
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