| 摘要 |
PURPOSE: To obtain an optical head device with which the operating performance is stable, a speed is high and the reduction in the size and weight is possible. CONSTITUTION: A semiconductor laser 21A is installed at approximately the central part of the exit surface of an objective lens 22A and luminous fluxes are made incident on the objective lens 22A and are condensed to a recording surface S by a reflection mirror 23A installed on the bottom of the lens. The reflected return light from this recording surface S is separated toward a photodetector 25A by a hologram element 26A installed on the bottom of the objective lens 22A. |
