Printing press paper web movement monitor - has paper passed between photoresistor and fibre bundle connected to light source

摘要

The equipment monitors the progress of strip material, particularly paper through a printing press, using a light-sensitive receiver irradiated by a light source. The paper (10) passes between a light-sensitive resistance (13), connected via an amplifier (11) to a switch (12) controlling the printing operation, and a light source. The latter is formed by a fibre bundle (15) illuminated by a lamp (14). The amplifier can be a three-stage transistor amplifier, and the bundle can be formed by flexible fibres.