| 摘要 |
An apparatus for the redistribution of acoustic energy is provided which comprises a lens having a reflective surface defined by the surface of revolution R1 of an elliptical arc A1 rotated about a line L through an angle alpha 1 and the surface of revolution R2 of an elliptical arc A2 rotated about the line L through an angle alpha 2. Each elliptical arc A1 and A2 constitutes a portion of an ellipse E1 or E2 having a focal point located at a point F1 on line L, and shares an end point P which lies on the reflective surface and the line L. The angle alpha 1 is chosen such that the surface of revolution R1 is convex with respect to an adjoining surface S1 and the angle alpha 2 is chosen such that the surface of revolution R2 is concave with respect to the adjoining surface S1. |
