| 摘要 |
PURPOSE: To obtain an optical information recording/reproducing apparatus which can detect a signal by dividing a data signal and a servo signal and moreover remove adverse influence by unwanted light beam. CONSTITUTION: A prism block 12 is provided with an anamorphic prism 19 for shaping the cross-section of optical flux from an anamorphic prism 18 into a circle, a condensing lens 21 coupled thereto and a right-angle prism 20. Contact surface of the anamorphic prism 19 and the right-angle prism 20 is finished as a half-mirror surface 22 to have the special shape and arrangement to prevent adverse influence of unwanted light beam. A part of the optical flux from a light source 11 is reflected by the half-mirror surface 22, condensed to a light receiving element 50 by the condensing lens 21, while the other optical flux passes through the half-mirror surface 22 and is then reflected by a rising mirror prism 23. The light receiving element 50 generates a signal for automatic output adjustment of a semiconductor laser 16, depending on the intensity of the incident optical flux. |
