The present invention relates to an optical pickup device that reproduces information recorded on a recording surface of an optical disk, or records information on the recording surface, and an optical disk apparatus using the same.
Conventionally, in optical pickup devices, a semiconductor laser, a laser drive IC, a high-frequency module, an optical detector, focusing coils, and tracking coils, which generate heat at the time of recording and reproduction, are mounted. When these heat generating parts generate heat, temperature of an optical pickup device rises to bring about a fear that generated heat causes degradation in performance, deterioration in service life, malfunction, etc. of parts. Hereupon, in order to dissolve such disadvantage, an optical disk apparatus described in JP-A-2003-45053 includes weights bonded to a focusing coil and a tracking coil, the weights being partially exposed to the atmosphere to heighten an efficiency of heat radiation.
As described above, heat generated from the focusing coil and the tracking coil in the optical disk apparatus described in JP-A-2003-45053 is radiated to the atmosphere through the weights bonded to the coils. Since the performance of heat radiation from the weights to the atmosphere is dependent upon the rotating speed of an optical disk, it is decreased when the rotating speed of an optical disk is low. That is, in the case where an optical pickup device is one for CD, DVD, etc., a major part of heat generated from a focusing coil and a tracking coil is transmitted to a pickup housing at the time of low-speed recording, so that temperature of the pickup housing rises. As a result, temperature of a semiconductor laser mounted on the pickup housing rises. When temperature of the semiconductor laser rises, degradation in performance and shortening in service life are caused in the semiconductor laser.
USPTO Backgrounds
USPTO Backgrounds