Abstract: A circuit for preventing destruction of a semiconductor laser element of an optical disc device comprises a light-emission-directing circuit part for outputting a light-emission-directing signal for directing the semiconductor laser element to emit light; a voltage-monitoring circuit part for monitoring a light-emitting voltage and, when a judgment is made that the light-emitting voltage is normal, outputting a light-emission-permitting signal for permitting the semiconductor laser element to emit light, the light-emitting voltage being supplied from a power source for the semiconductor laser element to an optical-output-controlling circuit part in order to cause the semiconductor laser element to emit light; and a light-emission-permitting circuit part for using the optical-output-controlling circuit part to cause the semiconductor laser element to emit light only when the light-emission-directing signal and the light-emission-permitting signal are inputted.

Abstract: An optical disc drive is disclosed. The optical disc drive comprises an optical pickup base including an optical pickup movable in the radius direction of an optical disc; and a main base holding the optical pickup base, wherein the main base comprises a guide rib protruding from the main base and guiding the air flow generated by the rotation of the optical disc to the optical pickup. Further, the optical pickup comprises an air spoiler for preventing contamination of an objective lens included in the optical pickup. The optical disc drive is able to control the temperature of an optical pickup unit by guiding the air flow generated by the rotation of an optical disc to the optical pickup. Moreover, the optical disc drive can reduce contamination of the objective lens of the optical pickup due to the air flow generated by the rotation of the optical disc.

Abstract: The following problem associated with optical pickup devices is solved: the temperature of a laser element is increased by excessive temperature rise in a laser driver circuit and this degrades the quality of writing and reading information to and from an optical disc. In an optical pickup enclosure, there is formed a groove recessed into a U shape, extended from the upper surface thereof opposed to an optical disc to the lower surface of the optical pickup enclosure. An air guide passage through which an air flow is passed is formed of this groove recessed into a U shape and a circuit board fastened to the outer circumferential side of the optical pickup enclosure with a screw. At this time, the laser driver circuit element is attached to the side of the circuit board opposed to the air guide passage. In a radiation cover attached to the upper surface of the optical pickup enclosure and in thermal contact with the laser element, an opening is formed.