| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk device capable of performing the pulling-in of a focus servo surely by properly switching circuit constitution which is usually equipped in the optical disk even when a laser beam of a blue wavelength is used as a laser beam for recording and reproduction. <P>SOLUTION: In the optical disk device, when an optical disk corresponding to the laser beam of the blue wavelength is loaded, the pulling-in of the focus servo is performed not using the laser beam of the blue wavelength but using a laser beam of red or infrared wavelength. As a result, the amplitude of a focus error signal which is generated during the pulling-in of the focus servo can be made large and the pulling-in operation of the focus servo based on the focus error signal can be performed smoothly. Moreover, since the optical device uses only irradiation means of other wavelengths which are equipped in the device from the beginning, special circuit constitution is not needed in addition in the device and the simplifying of the constitution of the device can be attained. <P>COPYRIGHT: (C)2007,JPO&INPIT |
