OPTICAL TYPE SCANNER

摘要

PURPOSE: To realize an optical scanning device in which first and second types of recording media are reproduced without enlarging a beam diameter. CONSTITUTION: The radiation beam 5 of first wavelength is emitted from a radiation source 4. A scanning spot 7 formed by the radiation beam follows the center line of a track to be scanned in the first type of recording medium which is designed for the first wavelength. When the second-type of recording medium in which information is recorded as a phase structure body designed for second wave length being longer than the first one is reproduced, the reading spot by this invention does not follow the center line 18 but rather the edge part of the track 38. In this case, an information signal with performance for satisfying not only the first type of recording medium but also the second type of recording medium is generated.