OPTICAL PICKUP INTERCHANGEABLE WITH OPTICAL RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an optical pickup in which a special variable disphragm is not needed and which is can be interchanged with all of a CD type and a DVD(digital video disk) type recording mediums. SOLUTION: This optical pickup is provided with a first laser beam source 31 emitting a light having relatively short wavelength, a first photodetector 34 detecting a reflected light with respect to the releatively short wavelength and an objective lens 38 in which an annular light shielding area is formed in between a paraxial area whose radius is relatively short and a far-axial area whole radius is relatively large. Moreover, the pickup is constituted of a laser unit 44 which emits a light having a relatively long wavelength and which detects only a light passing through the paraxial area of the objective lens 38 in among the reflected light having the relatively long wavelength and plural optical dividers 32, 35, 42 which make lights to be emitted from the first laser beam source 31 and the laser unit 44 proceed to the objective lens 38 and make the light reflected from an optical recording medium proceed to one side of either the first photodetector 34 or the laser unit 44.