| 摘要 |
PROBLEM TO BE SOLVED: To easily identify management information without damaging functions of parts by adhering to the whole or part of the parts a color for identifying management information having a wavelength absorption area in a band where a wavelength range of a laser light is removed. SOLUTION: Optical parts constituting the optical pickup, for example, a diffraction grating 3, a polarizing beam splitter 4, a detecting lens 5, a collimator lens 7, a reflecting mirror 8 and an objective lens 9 are all formed of a plastic resin. Each of the optical parts is prepared to be colored totally in accordance with a preliminarily set arrangement. A characteristic curve of a transmittance of a coloring agent is set so that the transmittance becomes nearly 0% in a band of not higher than approximately 550 nm, and becomes nearly 100% in a long wavelength band including wavelength components of a laser light. A difference of management information of the optical parts colored in accordance with the predetermined arrangement can be simply distinguished from a difference of colors. |
