Patent ID: 7545726

Claim:
An optical disc drive comprising: a light source including a red/infrared unit and a blue LD, the red/infrared unit being configured to generate both a red beam and an infrared beam, the blue LD being configured to generate a blue beam; an objective optical system for condensing light from the light source onto a recording surface of an optical disc, the objective optical system including a first and a second object lenses having different focal distances and arranged side by side in a circumferential direction of the disc; a chassis that is movable radially of the optical disc and supports both the light source and the objective optical system; an erecting optical system disposed farther away from the optical disc than the objective optical system for causing two beams propagating circumferentially of the disc in opposite directions to be directed toward the first and the second object lenses, respectively; a first optical path provided between the red/infrared unit and the first object lens, the first optical path including a first section extending circumferentially of the disc to the erecting optical system and a second section extending from the erecting optical system to the first object lens; and a second optical path provided between the blue LD and the second object lens, the second optical path including a third section extending, in an opposite direction to the first section of the first optical path, to the erecting optical system and a fourth section extending from the erecting optical system to the second object lens.