To provide an optical head device and an optical disc apparatus which monitor laser beam intensity to prevent a light quantity control circuit, which reflects the laser beam intensity on a laser element driving current, from being saturated depending on the laser beam intensity, whereby stable APC control can be performed irrespective of a kind of an optical disc.
According to one embodiment the present invention, an APC (Automatic Power Control) photodetector 43 accepts a light beam branched from a light beam toward a recording medium by a branching mirror 29 and detects intensity of a light beam supplied from a light source, a light quantity adjusting element 41 adjusts the intensity of the light beam, and the intensity of the light beam incident to the APC photodetector is changed in a continuous manner or a stepwise manner by the light quantity adjusting element 41. Therefore, when the single APC photodetector detects recording and reproducing light beams, the recording and reproducing light beams can fall within a dynamic range of the APC photodetector.
IWATA KATSUO
NAGATA KAZUHIRO
Satoshi Kono
Makoto Nakamura
Kurata Masatoshi
Takashi Mine
Yoshihiro Fukuhara
Sadao Muramatsu
Ryo Hashimoto
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