| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact and inexpensive optical pickup apparatus which precisely controls laser output. <P>SOLUTION: Laser beams respectively emitted from a plurality of laser beam sources 1, 2 and 3 are made to enter a dichroic prism 12 and to be emitted from a common emission opening. The emitted laser beams are split into main beams and monitoring beams with a prescribed light quantity ratio by a beam splitting element 15. The main beams are condensed on the information recording surface of an optical disk 31 and the monitoring beams are received by a monitor detector 27 to be converted to electric signals. On the basis of the obtained electric signals, control means 29 and 30 control the output power levels of the respective laser beam sources. The monitor detector comprises an arithmetic amplifier, a plurality of variable resistors, and an analog switch which switch-connects to the input path of the arithmetic amplifier for each laser beam source depending on a selection signal from outside. <P>COPYRIGHT: (C)2009,JPO&INPIT |
