| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical path compensation apparatus compensating an optical path of a three wavelength laser corresponding to a CD, a DVD and a BD and to provide an optical pickup corresponding to three waves. <P>SOLUTION: The optical path compensation apparatus 14 is provided with a first wavelength plate 15, a first double refraction plate 16, a second wavelength plate 17, a second double refraction plate 18 and a third wavelength plate 19 and is disposed on the front side of the three wavelength laser 20. In the optical path compensation apparatus 14 corresponding to three wavelengths, two double refraction plates are used, laser beams respectively having a wavelength λ<SB>1</SB>and a wavelength λ<SB>2</SB>emitted by the three wavelength laser are transmitted through the same optical path using the first double refraction plate 16 and then the laser beams having the wavelength λ<SB>1</SB>and the wavelength λ<SB>2</SB>and a laser beam having a wavelength λ<SB>3</SB>emitted by the three wavelength laser are transmitted through the same optical path using the second double refraction plate 18. <P>COPYRIGHT: (C)2007,JPO&INPIT |
