| 摘要 |
<p>Bottom-edge margin indicators for typewriter paper and the like using an optical sensor-monitor wherein spurious effects of the edge of the paper exiting from the bottom margin sensor region and pre-printed material thereon are obviated, and in which the sensor-monitor of the bottom edge of the paper is preferably carried by the platen shield (2) itself in a manner that is particularly advantageous for optical sensing of the paper, with the sensor (7-7 min ) maintained in extremely close proximity to the paper irrespective of its thichness, and adapted for simple and ready adjustment, if desired, to vary the margin setting.</p> |
