Using a light curtain to guard machinery

摘要

Light curtains are commonly used trip devices and are often used on power presses, hydraulic presses, guillotines, trimmers and palletisers. They operate by detecting an obstruction in the path taken by a beam or beams of light. The device may consist of a single beam ora number of beams of light in horizontal or vertical "curtains". The light may be visible or invisible (eg infrared) and may be continuous or modulated, (eg a scanning system).