| 摘要 |
PROBLEM TO BE SOLVED: To assure a signal intensity level at a sufficiently high level by using the light beams of light sources which emit the light beams of the wavelengths which are absorbed to a lesser degree by dyestuff at the time of reproducing a recording medium formed with a recording film by using the dyestuff. SOLUTION: The disk formed with the recording film by using the dyestuff is reproduced by using the laser beams(LBs) from first and second semiconductor lasers 1, 2 on long and short wavelength sides. The absorption of the LBs by the dyestuff of the recording film is large with the LB from the laser 2 at present but is larger with the LB from the laser 1 in some cases from the relation with the material quality of the dyestuff of the recording film. In such a case, both of the second pupil part 10 of a pupil filter 7 and the filter surface 5 of a beam splitter 4 are formed by a wavelength selective dichroic filter. As a result, the sufficient signal intensity level is obtd. by selectively switching the third pupil different in the diameter from the diameter of the first and second pupil parts 9, 10 by using the LB from the laser 2. |
