| 摘要 |
1,217,642. Photo-electric inspection. OMRON TATEISI ELECTRONICS CO. March 24, 1969 [April 8, 1968j, No.15268/69. Heading G1A. A moving web is inspected photo-electrically for faults which involve defective parts standing out from its surface by a narrow beam of light close to the surface and directed across the web at right angles to the direction of movement, total or partial reflection of the beam by a defect being detected by a lateral array of photo-cells. The beam which may be a laser beam may cross the web in the vicinity of a roller, and may be chopped to facilitate amplification and two close parallel beams may be directed one from each other. The apparatus may include additional fault detecting apparatus for holes or marks, the light beam of which may shine through the web and the detector of which may respond to its absorption or reflection. In a circuit for the point control of a fault marking system including the detectors of two lateral arrays, outputs of corresponding detectors are applied after pre-amplifications to provide with the output of another pair the input to a differential amplifier the output from which is used to effect control or marking error a threshold circuit. |
