| 摘要 |
PROBLEM TO BE SOLVED: To provide an information reproducing/recording device for a recording medium wherein reflected light losses from the recording medium are limited. SOLUTION: An emitted light from the laser diode 12 of a wavelength 780 band is set to be an S-polarized light. A polarization plane rotating means 2 (λ/4 phase plate) is arranged between a super-resolution cut-off filter 10A constituted of a polarization filter film 34 and an objective lens 16. During DVD reproducing, the objective lens 16, the polarization plane rotating means 2 and the super-resolution cut-off filter 19A are arranged in an optical path. The S-polarized light is drawn to a very small spot diameter by the super- resolution operation of the super-resolution cut-off filter 10A and the objective lens 16. The S-polarized light reflected by the recording medium is converted into a P-polarized light by reciprocating the polarization plane rotating means 2. The P-polarized light is passed through the super-resolution cut-off filter 10A without any losses, and received by a photodetector 90. |
