| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve optical characteristics of a wide band 1/4 wavelength plate and to reduce the number of optical components constituting an optical pickup. <P>SOLUTION: The wide band wavelength plate is configured by laminating two wavelength plates across a spacer in order to eliminate the wavefront aberration of a 1/4 wavelength plate, and includes gaps in optical surfaces of the two wavelength plates. A wide band 1/4 wavelength plate 20 is formed by laminating a 1/2 wavelength plate 17 and a 1/4 wavelength plate 18 across a frame-shaped spacer 21. Thus, the optical surfaces of the 1/2 wavelength plate 17 and the 1/4 wavelength plate 18 are laminated together via a gap 22, thereby eliminating the wavefront aberration of the wide band 1/4 wavelength plate 20. <P>COPYRIGHT: (C)2010,JPO&INPIT |
