Patent ID: 6876620

Claim:
An optical storage device capable of at least reproducing information recorded on first and second optical storage media different in distance from a medium surface on which a light beam is incident to a recording surface and in operating wavelength, said optical storage device comprising: a first light emitting element for emitting a light beam having a first wavelength; a second light emitting element for emitting a light beam having a second wavelength different from said first wavelength; a first photodetector for detecting a reproduction signal from a light beam reflected on said first optical storage medium; a second photodetector for detecting a reproduction signal from a light beam reflected on said second optical storage medium; a first optical element for combining optical paths of said light beams emitted from said first and second light emitting elements; a first collimator lens located between said first light emitting element and said first optical element for collimating said light beam emitted from said first light emitting element; a second collimator lens located between said second light emitting element and said first optical element for collimating said light beam emitted from said second light emitting element; an objective lens located commonly on said optical paths combined by said first optical element for optimally focusing said light beam emitted from said first light emitting element onto said first optical storage medium; a second optical element located between said second light emitting element and said first optical element for producing a rotationally symmetrical aberration compensating for an aberration occurring on said second optical storage medium, in said light beam emitted from said second light emitting element; and an aperture limiting member for limiting the diameter of said light beam emitted from said second light emitting element.