| 摘要 |
<p>A vehicle (1) includes an optical device (3) mounted on the exterior of the vehicle at the rear corner thereof. The device (3) consists of a part only of a Fresnel lens having a negative focal length with the optical centre of the lens lying adjacent to or outside of the outer side of the lens. The device (3) gives a driver good vision of the area behind the vehicle when reversing. </p> |
