Device for protecting a danger zone, especially the danger zone of an automatic machine

摘要

The invention relates to a device for protecting a danger zone (26), especially the danger zone (26) of an automatic machine (28). The inventive device (10) comprises first means (12, 16) for producing an optically monitored, virtual barrier (30) and second means for generating a switch signal that stops the machine (28) when said barrier (30) is broken through (24). The first means (12, 16) are provided with an image recording element (12) and a defined target (16) the image of which is recorded by the image recording element (12). The second means contain a comparative element that compares the recorded image with a value that is characteristic of a reference image. The inventive device is further characterized in that the defined target (16) contains position marks that are used to determine its present position.