| 摘要 |
PURPOSE:To detect whether a body is present or not and its position and shape by positioning a stripe pattern consisting of parts which differ in reflectance on the background of the body and scanning a light spot so that the spot crosses stripes. CONSTITUTION:The body 2 is conveyed while being mounted on a disk 1 where black and white stripes are drawn on the surface in the conveyance direction of a conveyor 3. The laser beam from a laser beam generating device 5 is reflected downward by a rotary mirror 4 to scan across the dish 1, reflected light from the dish 1 and body 2 is photodetected by a photoelectric converting element 6 through a mirror 4, and the output of the element 6 is amplified 7 and supplied to a binary coding circuit 8. The output signal of the circuit 8 is a pulse signal and a timer circuit 9 clocks the time from the leading edge to the trailing edge of each pulse and supplies the output to an arithmetic circuit 10, which specified the position and length of the body 2 in the scanning direction of the laser beam and the moving direction of the body 2, calculating the position and shape of the body.
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