Bottom margin indicator apparatus for typewriters and the like

摘要

This disclosure is concerned with improved 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 itself in manner that is particularly advantageous for optical sensing of the paper, with the sensor maintained in extremely closed proximity to the paper irrespective of its thickness, and adapted for simple and ready adjustment, if desired, to vary the margin setting.