Optical disk device

An optical disk device comprising:

• optical means for extracting information stored on a disk;
• control means for controlling said optical means;
• signal process means for optimally converting a regenerated signal extracted by said optical means into a binary signal;
• reference clock generation means for generating a reference clock substantially equal to a basic transfer speed of the regenerated signal from a fixed clock;
• and
• data clock extraction means for extracting a clock element from binary data of the regenerated signal;
• said reference clock generation means comprising:
• a first divider for dividing the fixed clock;
• a second divider for dividing the reference clock;
• a first phase comparator for detecting a phase error between a division clock output by said first divider and a division clock output by said second divider;
• a first voltage/current control oscillator oscillating at a frequency depending on the phase error output by said first phase comparator;
• and
• central frequency setting means for setting a central oscillation frequency of said first voltage/current control oscillator;
• said data clock extraction means comprising:
• a second phase comparator for detecting a phase error between the regenerated binary data and a data clock;
• and
• a second voltage/current control oscillator oscillating at a frequency depending on the phase error output by said second phase comparator;
• whereby characteristics of said first voltage/current control oscillator are set equal or similar to the characteristics of said second voltage/current control oscillator, and the oscillation frequency of said first voltage/current control oscillator is referred to by said second voltage/current control oscillator.

An optical disk device comprising:

• optical means for extracting information stored on a disk;
• control means for controlling said optical means;
• signal process means for optimally converting a regenerated signal extracted by said optical means into a binary signal;
• reference clock generation means for generating a reference clock substantially equal to a basic transfer speed of the regenerated signal from a fixed clock;
• and
• data clock extraction means for extracting a clock element from binary data of the regenerated signal;
• said reference clock generation means comprising:
• a first divider for dividing the fixed clock;
• a second divider for dividing the reference clock;
• a phase comparator for detecting a phase error between a division clock output by said first divider and a division clock output by said second divider;
• a first voltage/current control oscillator oscillation at a frequency depending on the phase error output by said phase comparator;
• and
• setting means for setting a central oscillation frequency or a gain of said first voltage/current control oscillator;
• said data clock extraction means comprising:
• a second voltage/current control oscillator having at least characteristics equal to characteristics of said first voltage/current control oscillator;
• and
• synchronization detection means for detecting a synchronization state of said data clock extraction means;
• whereby characteristics of said signal process means can be optimally varied based on a detection state of said synchronization detection means.

An optical disk device comprising:

• reference clock generation means for generating a reference clock substantially equal to a basic transfer speed of the regenerated signal from a predetermined fixed clock;
• said reference clock generation means comprising:
• a first divider for dividing the fixed clock;
• a second divider for dividing the reference clock;
• a phase comparator for detecting a phase error between a division clock output by said first divider and a division clock output by said second divider;
• a charge pump for converting the phase error detected by said phase comparator into a voltage or an amount of electric current;
• and
• a voltage/current control oscillator for oscillation at a frequency depending on the phase error output by said phase comparator;
• whereby a gain of said reference clock generation means is varied based on an amount of division of said first divider.