| 摘要 |
<p>A laser beam emitted from a laser diode is shaped into a vertically narrow light beam having a limited horizontal width and scanned horizontally. The light beam reflected by the object is captured by a horizontally oblong light receiving area which is scanned vertically and has a limited vertical width, and received by a photodiode. Even if the vertical width of the light beam is large enough to absorb the vertical error of attachment of the radar, by vertically scanning the horizontally oblong light receiving area, the period during which the direct rays from the sun enter the light receiving area and consequently the detection is impossible can be shortened. With this constitution, except the case where the height of the sun coincides with the height of the object, the influence of the direct rays of the sun can be minimized, and the object can be detected reliably without precise aiming.</p> |
