| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve a high speed transfer rate and high density recording by increasing the rotational speed of an optical recording medium so as to increase the linear velocity. <P>SOLUTION: The controller of semiconductor laser is provided with a semiconductor laser 12 that emits laser light beams by which the optical recording medium is illuminated, first and second current sources 14a and 14b which are connected to the semiconductor laser 12, a fist switch 21a which switches the current being supplied to the semiconductor laser 12 from the first current source 14a into first and second levels and a second switch 21b which controls the current being supplied to the semiconductor laser 12 from the second current source 14b. In the erasing period of information signals to the optical recording medium, current from the second current source 14b is supplied to the semiconductor laser 12 under the control of the second switch 21b. The first switch 21a conducts the switching operation based on the signals having the same frequency during the recording or high frequency superimposed signals of the reproducing. Laser light beams from the semiconductor laser 12 is emitted based on the switching operations of the first switch 21a. <P>COPYRIGHT: (C)2007,JPO&INPIT |
