| 摘要 |
PROBLEM TO BE SOLVED: To provide a recording/reproducing device capable of reproducing a great variety of optical disks without increasing the number of light sources. SOLUTION: A variable BPF 4 is positioned between the LED light source 1 having wide spectrum range and the optical disk 2. A multi-dividing BPF part dividing the light beam for every wavelength is furnished on the variable BPF 4, and only the light beam having a required wavelength is passed by making the divided light beam pass through the light beam passing band. Consequently, only the light beam having the wavelength in the band required for reproducing the optical disk 2 among the light beams entered into the variable BPF 4 is passed through the variable BPF 4 and converged to a recording layer of the optical disk 2, then the recorded information is reproduced in accordance with the intensity of this reflection. Also a diffraction grating may be used as the means to pass the required light beam. |
