US 6,552,987 B1Granted

Optical disk apparatus wherein recording clock signal is stopped being supplied to semiconductor laser drive circuit on optical pickup during reproduction operation

AssigneeHitachi, Ltd.

InventorsAkihiro Asada, Toshimitsu Kaku, Takashi Hoshino, Masaaki Kurebayashi

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Abstract

According to the present invention, in an optical disk apparatus constructed to supply signals for controlling a semiconductor laser drive circuit provided to an optical pickup from a signal processing circuit through a flexible cable, the semiconductor laser drive circuit is so constructed as to generate a drive current signal for the semiconductor laser on the basis of a binary signal and a clock signal which are supplied from the signal processing circuit through the flexible cable and the signal processing circuit is so constructed as to supply the clock signal during recording of data and stop the supply of the block signal during reproduction of data.

Claims13

Dependent claims

An optical disk apparatus comprising:

a flexible cable;
a semiconductor laser drive circuit, connected to the flexible cable, including
laser drive (LD) recording drive current waveform generating means for generating a recording drive current waveform for a semiconductor laser based on a clock signal when recording information on a recording medium, and
reproduction drive current supply means for supplying a reproduction drive current to the semiconductor laser when reading information from the recording medium;
recording clock supply means, connected to the flexible cable, for supplying the clock signal to the semiconductor laser drive circuit through the flexible cable;
signal processing means, connected to the flexible cable, for supplying mark length information representing information to be recorded on the recording medium to the semiconductor laser drive circuit through the flexible cable;
recording/reproduction mode control means for controlling a recording/reproduction operation of the semiconductor laser drive circuit;
and
clock stop means for stopping the clock signal from being supplied from the recording clock supply means to the semiconductor laser drive circuit when an output of the recording/reproduction mode control means designates a reproduction operation;
wherein the laser drive (LD) recording drive current waveform generating means generates the recording drive current waveform based on the mark length information and the clock signal.

7 more elements

An optical disk apparatus comprising:

a flexible cable;
a semiconductor laser drive circuit, connected to the flexible cable, including
multiplying means for generating a second clock signal having a frequency which is n times a frequency of a first clock signal (n being a positive integer),
laser drive (LD) recording drive current waveform generating means for generating a recording drive current waveform for a semiconductor laser based on the second clock signal when recording information on a recording medium, and
reproduction drive current supply means for supplying a reproduction drive current to the semiconductor laser when reading information from the recording medium;
recording clock supply means, connected to the flexible cable, for supplying the first clock signal to the semiconductor laser drive circuit through the flexible cable;
signal processing means, connected to the flexible cable, for supplying mark length information representing information to be recorded on the recording medium to the semiconductor laser drive circuit through the flexible cable;
recording/reproduction mode control means for controlling a recording/reproduction operation of the semiconductor laser drive circuit;
and
clock stop means for stopping the first clock signal from being supplied from the recording clock supply means to the semiconductor laser drive circuit when an output of the recording/reproduction mode control means designates a reproduction operation;
wherein the laser drive (LD) recording drive current waveform generating means generates the recording drive current waveform based on the mark length information and the second clock signal.

8 more elements

An optical disk apparatus constructed to supply signals for controlling a semiconductor laser drive circuit carried on an optical pickup from a signal processing circuit to the semiconductor laser drive circuit through a flexible cable;

wherein the semiconductor laser drive circuit is constructed to generate a drive current signal for a semiconductor laser based on a binary signal representing data to be recorded using the optical pickup and a clock signal which are supplied from the signal processing circuit to the semiconductor laser drive circuit through the flexible cable;
and
wherein the signal processing circuit is constructed to supply the clock signal to the semiconductor laser drive circuit through the flexible cable during recording of data, and to stop supplying the clock signal to the semiconductor laser drive circuit through the flexible cable during reproduction of data.

An optical disk apparatus constructed to supply a signal for controlling a semiconductor laser drive circuit carried on an optical pickup from a signal processing circuit to the semiconductor laser drive circuit through a flexible cable;

wherein the semiconductor laser drive circuit is constructed to generate a drive current signal for a semiconductor laser based on a binary signal representing data to be recorded using the optical pickup and a clock signal which are supplied from the signal processing circuit to the semiconductor laser drive circuit through the flexible cable;
and
wherein the signal processing circuit is constructed to supply the clock signal to the semiconductor laser drive circuit through the flexible cable during a period in which the binary signal is supplied from the signal processing circuit to the semiconductor laser drive circuit through the flexible cable, and to stop supplying the clock signal to the semiconductor laser drive circuit through the flexible cable during a period in which the binary signal is not supplied from the signal processing circuit to the semiconductor laser drive circuit through the flexible cable.

Dependencies are inferred from the claim text.