| 摘要 |
A lighting apparatus comprises a housing having an opening, a light source received in the housing and a light transmitting-cover (12) fixed at the opening of the housing and through which light rays are projected from the light source. The light transmitting-cover (12) includes a plate made of light transmitting-material and having a first surface and a second surface. Segment lens elements of the same size are arranged on the first and second surface of the plate and formed integrally with the plate. The segment lens elements on the first surface (33A) are positioned in face-to-face relation with the segment lens elements arranged on the second surface (33B), thus forming a segment lens (31). The segment lens elements have a common optical axis (32) and convex surfaces (33A, 33B), respectively. The focal lengths defined by these convex surfaces (33A, 33B) are equal. The focal point of one of the segment lens elements lies on the convex surface of the other segment lens element, and that of the other segment lens element lies on the convex surface of the other segment lens element.
|
