Patent ID: 8379503

Claim:
An optical information recording reproduction apparatus comprising: a first light beam source; a second light beam source emitting a beam with a wavelength shorter than that of the first light beam source; and an object lens condensing the beams from the first and second light beam sources to an optical information recording medium, wherein when information is recorded in the optical information recording medium, a recording beam is emitted from the first light beam source and a beam used to generate a signal for controlling a position of the object lens is emitted from the second light beam source, and wherein when the information of the optical information recording medium is reproduced, a reproduction beam is emitted from the second light beam source; an optical attenuator, wherein the optical attenuator adjusts a beam quantity which is supplied from the second light beam source and is incident on the optical detection unit in the recording so as to be the same as a beam quantity which is supplied from the second light beam source and is incident on the optical detection unit in the reproducing.