Proximity detector using light sources - produces intersecting beams which form spots on target with separation dependent on distance between source and target

摘要

The proximity detector is illustrated by an example using a bomb (1) to which two light sources (5,6) are attached. These produce beams of light (7,8) directed towards the target surfaces with thier axes crossing some distance in front of the bomb. The light emitted is modulated or pulsed either by mechanical or electrical means. In the centre of the nose of the bomb there is a light receiver (10) sensitive to light reflected from the object. The two beams form two spots of light on the target object which approach each other as the bomb nears the target. When the bomb is at a specified distance from the target the spots of light overlap. The light intensity received by the receiver (10) is increased and then passes through a maximum. This is used to provide the required indication of promixity. The receiver may be receptive to light from a limited angle to minimise ambient light disturbance.