| 摘要 |
PURPOSE:To measure the main optical axis of a head light by producing the balance exactly the same as the balance of the illuminances at the prescribed two points located remote from the head light near the head light by means of a pair of lenses and measuring this. CONSTITUTION:If it is assumed that a head light 1 deviates by an angle alpha as shown, the direction of its main optical axis deviates by the angle alpha as well to a direction (b), and the illuminance chart of a surface S of that time deviates by the angle alpha as well. Then, sensing parts 3, 3' sense illuminances l2, l3, respectively. Since the illuminances bear unbalance, a sensing body 2 moves automatically in the direction where the parts 3, 3' attain the same illuminance, and when the parts 3, 3' come to the positions P2, P2', both parts 3, 3' sense the same illuminance l4 and the body 2 stops. The angle alpha of deviation and illuminance of the head light 1 are measured by the distance moved during this time. |
