| 摘要 |
PURPOSE:To provide a photoelectric converting element on an optional position, by providing a pair of glass fibers in the proximity of a condensing element so as to photodetect a diffracted light beam from an information carrier, and leading it to the photoelectric converting element. CONSTITUTION:A diffracted light beam by pits 9 of an optical disk 7, which has been incident from each one end of a pair of glass fibers 31 passes through the glass fibers 31 and are projected form the other ends, respectively. On the end parts of the glass fibers, photodetectors 5, 6 are provided, and their outputs are provided to a differential amplifier 32 and are outputted as a position correcting signal of a condensing spot. According to such a constitution, the photodetectors 5, 6 and the differential amplifier 32 are provided on an optional position, and also the pickup is made small-sized. |
