| 摘要 |
<p>The light barrier generates a signal in response to an object, esp. a plate shaped object, passing between a light source (7) and receiver (9) and is designed to detect objects of varying transparency, including clear glass objects. The direction of the light beam forms an acute angle with the transport plane of the object. The angle is less than 45 degrees. Two coaxial cylindrical channels form the light path either side of the transport plane. One has the light source and the other the receiver at its end remote from the transport plane.</p> |
