Optical storage device and emission control method
AssigneeFujitsu Limited
InventorTakashi Masaki
Life of this patent
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Abstract
An optical storage device decreases the influence of return light to the laser light source and prevents an increase of power consumption even if high frequency superimposing is performed. The optical storage device applies drive current, to which a high frequency signal is superimposed, to the laser light source, and reads/writes data from/in the storage medium. The high frequency superimposing is set to OFF as a default to save power consumption, and high frequency superimposing is turned ON only when it is judged that servo is unstable, and high frequency superimposing is turned OFF when it is judged that servo is stable.
Claims15
An optical storage device for writing and/or reading data to/from a storage medium using a laser beam, comprising:
- a light source for emitting the laser beam onto said storage medium;
- a servo controller for performing follow-up control of said laser beam on said storage medium according to the reflected light of said storage medium;
- a light source driver for applying drive current to said light source for said writing and/or reading;
- a signal generator for generating high frequency signals to be superimposed onto said drive current;
- and
- a controller for judging whether the laser emission of said light source is unstable from the servo control status by said servo controller, and superimposing said high frequency signals onto said drive current when judging that the laser emission is unstable, and
- wherein the controller cancels superimposing of said high frequency signals onto said drive current when judging that the laser emission is stable from the servo control status by the servo controller.
An emission control method of controlling emission of the laser light source for irradiating light onto a storage medium, comprising:
- a servo controlling step of performing follow-up control of said laser beam on said storage medium according to the reflected light of said storage medium;
- a step of judging whether emission of said laser light source is unstable from the servo control status by said servo control;
- a step of superimposing high frequency signals onto the drive current supplied to said laser light source when judging that the laser emission is unstable;
- and
- a step of canceling said superimposing of said high frequency signals onto said drive current when judging that the laser emission is stable from the servo control status by the servo control.
An optical storage device for writing and/or reading data to/from a storage medium using a laser beam, comprising:
- a light source for emitting the laser beam onto said storage medium;
- a servo controller for performing follow-up control of said laser beam on said storage medium according to the reflected light of said storage medium;
- a light source driver for applying drive current to said light source for said writing and/or reading;
- a signal generator for generating high frequency signals to be superimposed onto said drive current;
- and
- a controller for judging whether the laser emission of said light source is unstable from the servo control status by said servo controller, and superimposing said high frequency signals onto said drive current when judging that the laser emission is unstable;
- wherein said controller counts the number of times when said servo control became OFF, and judges whether said laser emission is unstable according to said count value.
Dependencies are inferred from the claim text.