| 摘要 |
<p>PURPOSE:To detect objects including light transparent objects by mounting an air flow generating part on an object carrying or moving passage and fitting an element for detecting the chang of air flow of an air flow passage to detect the arrival or passage of these objects. CONSTITUTION:Plural grippers 24 are arranged to the periphery of a transfer roller 33 and an opening 334 of an air flowing hole 333 passed from the external periphery to the direction of a rotational axis is drilled near the grippers 24. The other end of the rotational axis 34 is connected to a suction fan 37 by hoses. A hot wire e.g. is used as a detecting element, i.e., a tungsten wire 38 is stretched in an air flow passage inside the rotational shaft 34 of the transfer roller 33 and current is supplied to the wire 38 to heat it. When a transfer paper 201 is normally gripped, the whole wire 38 acts as high resistance during the rotation of the roller 33 and, in case of a gripping error, a part of the wire 38 between the gripping part and the transfer part is turned to low resistance, so that a light penetrating object also can be detected.</p> |
