INFORMATION RECORDING/REPRODUCING APPARATUS

WIPO Patent Application WO/2001/022412

A1

A laser waveform generating function is given not to a modulating circuit (6) but to a laser drive waveform generating circuit (2) close to a laser (3). A recording clock generating circuit (9) is included in the laser drive waveform generating circuit (2) to generate a clock of a higher frequency than that of a synchronizing clock (202). Thus, a recording laser current (waveform) can be generated without sending a signal of high frequency from the modulating circuit (6). Information can be recorded with high accuracy by using a recording laser current (waveform) of high accuracy while being hardly influenced by the delay precision between signals. During reproduction, e.g., reproduction of an ID portion, the feed of the synchronizing clock (202) is stopped, so that adverse effects such as obstruction to reproduction, e.g., reproduction of the ID portion can be reduced. Since the response speed of the recording clock generating circuit (9) can be switched, a clock of high precision can be generated. Therefore, the recording laser current (waveform) can be produced to record information with high accuracy.

HOSHINO TAKASHI (JP)
KAKU TOSHIMITSU (JP)
ASADA AKIHIRO (JP)
SEKINE TAKEHIKO (JP)

PCT/JP1999/005106

March 29, 2001

September 20, 1999

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HITACHI LTD (JP)
HITACHI VIDEO & INF SYST (JP)
HOSHINO TAKASHI (JP)
KAKU TOSHIMITSU (JP)
ASADA AKIHIRO (JP)
SEKINE TAKEHIKO (JP)

G11B7/0045; G11B7/005; G11B7/125; G11B20/14; G11B27/30; G11B7/007; (IPC1-7): G11B7/004; G11B7/125

EP0628960A1	1994-12-14
US5586098A	1996-12-17
JPH05258527A	1993-10-08
JPH0652569A	1994-02-25

Sakuta, Yasuo (Ltd. 5-1, Marunouchi 1-chome Chiyoda-ku Tokyo, JP)

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