| 摘要 |
PURPOSE:To make the optical head miniaturized, light and thin structive by using an optical element for converting a cross section shape of an optical beam. CONSTITUTION:An incident light beam is reflected by splitting into >= 2 in one direction on an reflecting surface of the optical element 10 formed in a sequential stepped shape as the reflecting surface set up at a prescribed inclination, thus changing the conversion ratio of the direction of a major axis to the direction of a minor axis of the cross section shape of the optical beam. By this method, a shaping prism for shaping the major axial direction and the minor axial direction of the optical beam of an ellipse, etc., in length and suppressing a loss quantity of light can be out of use, and the constitution of the optical head which should have been in complicated constitution can be simplified, while the miniaturization with light weight and thin formation can be attained. |
