| 摘要 |
Apparatus is disclosed which includes two side-by-side planar light sensors. A light stop is spaced from one light sensor in position to stop or shade half of the light sensor surface from a projected light beam when the beam is orthogonal thereto. The other light sensor is completely exposed to the projected light beam. The one light sensor is exposed to more or less of the light beam dependent upon the beam's departure in one direction or the other from orthogonality to the plane of the one light sensor. A ratio of the output from the one light sensor to the output from the other provides beam angle information relative to the plane of the one light sensor. |
