| 摘要 |
PURPOSE:To simplify an optical system by forming at least one pair of recording films separately having steep absorption edges close to each other. CONSTITUTION:A pair of recording films R1, R2 are formed. The film R1 has an absorption peak at a first specified wavelength W1, a steep absorption edge A1 at the longer wavelength side of the peak and a gently-sloping absorption region at the shorter wavelength side. The film R2 has an absorption peak at a second specified wavelength W2 which is slightly longer than the first wavelength W1, a steep absorption edge A2 at the shorter wavelength side of the peak and a gently-sloping absorption region at the longer wavelength side. The peaks W1 and W2 are set in the narrowest wavelength range of 10-100nm. An optical system can be made common to recording and reproduction and can be simplified. |
