Back to results
US 7,688,874 B2Granted
Semiconductor laser driving device, optical head, optical disk device, and semiconductor laser driving method
AssigneeKabushiki Kaisha Toshiba
InventorsNobuaki Kaji, Kazuo Watabe
Life of this patent
Estimating the term…
Abstract
A semiconductor laser driving device includes a current supply unit supplying current to a semiconductor laser; a first control unit controlling the current supply unit to supply a first current which is half or less of a lasing threshold of the semiconductor laser; and a second control unit controlling the current supply unit to supply a second current which is larger than the lasing threshold after a first time is passed from an edge of a clock signal.
Claims6
A semiconductor laser driving device, comprising:
- a current supply unit supplying current to a semiconductor laser;
- a first control unit controlling said current supply unit to supply a first current which is half or less of a lasing threshold of the semiconductor laser;
- a second control unit controlling said current supply unit to supply a second current which is larger than the lasing threshold after a first time is passed from an edge of a clock signal;
- an input unit inputting a signal representing light-emission intensity of the semiconductor laser, and a signal representing a second time from the edge of the clock signal to a start of light-emission of the semiconductor laser;
- a first decision unit deciding the first current based on the difference between the first and second times, the first current being the half or less of the lasing threshold;
- a second decision unit deciding the sum of the first and second current based on the light-emission intensity;
- and
- a third decision unit deciding the second current based on the sum and the decided first current.
5 more elements
A semiconductor laser driving method, comprising:
- supplying a first current which is half or less of a lasing threshold to a semiconductor laser;
- and
- supplying a second current which is larger than the lasing threshold to the semiconductor laser after a first time is passed from an edge of a clock signal;
- inputting a signal representing light-emission intensity of the semiconductor laser, and a signal representing a second time from the edge of the clock signal to a start of light-emission of the semiconductor laser;
- deciding the first current based on the difference between the first and second times, the first current being the half or less of the lasing threshold;
- deciding the sum of the first and second current based on the light-emission intensity;
- and
- deciding the second current based on the sum and the decided first current.
5 more elements
Dependencies are inferred from the claim text.