Patent ID: 6449237
Filing Date: 2002-09-10
Classification: G02B,G11B

Abstract:
An optical recording and pickup head for a plurality of optical discs for performing recording and reproduction of information with respectively different wavelengths, the optical recording and pickup head comprising:a first optical source for emitting first light having a relatively shorter wavelength; a second optical source for emitting second light having a relatively longer wavelength; a photo detector; an objective lens for focusing the light emitted from the first and second optical sources on the information recording surfaces of optical discs, respectively; an optical path altering unit for transferring the light emitted from the first and second sources to the objective lens and transferring the first and second light reflected from the information recording surfaces of the plurality of discs to the photo detector, respectively; and a flat plate lens for substantially totally transmitting the first light proceeding from the optical path altering unit to the objective lens and diffracting the second light proceeding from the optical path altering unit to the optical axis of the objective lens.