| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high performance objective lens optical system by improving light use efficiency and reducing stray light of the objective lens optical system in which the wavelengths of a light beam to be focused on the two or more optical recording media are the same, the wavelengths of the light beams to be focused on the two or more optical recording media are different, and light is focused on at least three optical recording media. <P>SOLUTION: The objective lens optical system focuses the light beam with a wavelength λ1 on an information recording surface of a first optical recording medium including a transparent substrate with a thickness t1, the light beam with the wavelength λ1 on an information recording surface of a second optical recording medium including a transparent substrate with a thickness t2, and the light beam with a wavelength λ3 on an information recording surface of a third optical recording medium including a transparent substrate with a thickness t3, by using a refraction action. Sectioning the area of the objective lens optical system is applied to a compatible technique for the same wavelengths, and generating an aberration for canceling a chromatic aberration caused by a difference in wavelength λ of the light beam is applied to a compatible technique for different wavelengths. <P>COPYRIGHT: (C)2008,JPO&INPIT |
