| 摘要 |
PURPOSE: An optical pick using a slim lens is provided to reduce the number of optical parts installed on an optical path from an objective lens to a photo detector, and arrange each optical part in a line. CONSTITUTION: A laser diode(11) scans a laser beam having a predetermined wavelength. A diffraction grid lens(12) diffracts and divides the laser beam output from the laser diode. A beam splitter(13) reflects a part of the laser beam transmitting the diffraction grid lens while transmitting the rest of the laser beam. A collimating lens(14) is arranged on one side of the beam splitter for setting the beam reflected and dispersed by the beam splitter as a parallel light. An objective lens(15) is arranged in front of the collimating lens for focusing the parallel light for forming an optical spot on an optical disk(D). A photo detector(16) is arranged on the other side of the beam splitter for detecting a signal from the light reflected from the optical disk. A monitoring photo diode(17) monitors a state of the laser beam based on the laser beam transmitting the beam splitter. |
