opto-electronic character counter for photo-composing machine - has photodetector responding to flashes arising during setting and supplying electronic counter

摘要

An electro-optical detector ascertains the number of characters set by a photo-composing machine. A photo-detector registers the light flashes and supplies a counter whose content is displayed. Pref. an amplifier and pulse shaper are assigned to the photo-detector. In the illustrated embodiment, a photo-detector respond to the light flashes appearing inside the housing of a photo-composing machine during a setting process. The photo-detector output is fed to an amplifier integrated with a pulse shaper. The latter serves to convert the pulses received from the detector into rectangular signals so that they can be processed without fear of error by the following electronic counter. Rapidly following pulses, belonging to a single character, are recognised as such and shaped to form a single pulse. The counter has inputs for start and stop signals and a resetting key.