Patent attributes
An optical system and pick-up device having an optical magnification suitable for three different optical disc formats and a light emitting means for emitting a laser beam having a wavelength corresponding to each disc in the optical system of the optical pickup for recording and/or reproducing an information signal to the optical discs. The optical pickup device has a first light emitting unit for emitting a laser beam having a first wavelength or a second wavelength, a second light emitting unit for emitting a laser beam having a third wavelength, a first collimator lens for transmitting the laser beams having the first or second wavelengths, a second collimator lens for transmitting the laser beam having the third wavelength, a first objective lens for transmitting the laser beams having the first or third wavelengths, and a second objective lens for transmitting the laser beam having the second wavelength.
