Reflective surface flying spot fault checker - has frosted image plate with output to photomultiplier

摘要

A laser source (2) projects its output onto a polygonal mirror wheel (3) which then projects the light ray (4) over the width of the reflecting surface (5). The direct reflected ray (4a) is diffused by a frosted opal glass plate (6) behind a diaphragm (7). The diffused light is received by a photomultiplier (8) mounted in a multiplying chamber (10) whose sides (9) are coated with reflecting material to increase the light at the photomultiplier. Errors due to reflections from the edges are discounted by a photomultiplier detector (14) which receives the ray (13) through a transparent glass blade (12) which divides this ray from the transmitted ray (4).