| 摘要 |
PROBLEM TO BE SOLVED: To enable the output of secondary harmonics in a drawing region, for example, to be stabilized at a desired value in an image projection device or the like. SOLUTION: The image projection device 1 is equipped with a distributed Bragg reflection semiconductor laser 2 having a DBR part 23 and a phase part 22, an optical wavelength conversion device 4 which converts fundamental waves 3 emitted from the semiconductor laser 2 to the secondary harmonics 5, a light deflector 7 which scans the secondary harmonics 5, and a modulation means 111 which modulates the semiconductor laser 2 responding to image signals. The method of controlling the distributed Bragg reflection semiconductor laser 2 in the image projection device is provided. A coefficient computing process of computing, at least, one of the coefficients used in an relational expression of currents injected into the DBR part 23 and the phase 22 for continuously shifting the wavelength of the fundamental waves 3 emitted from the semiconductor laser 2 and a wavelength adjusting process of adjusting the output of secondary harmonics by changing currents injected into the DBR part 23 and the phase part 22 resting on the relational expression are carried out within a non-drawing time when no image signal is present. COPYRIGHT: (C)2006,JPO&NCIPI
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