DUAL FUNCTION CONTRAST INDICATING ARRANGEMENT IN PHOTOELECTRIC SENSING SYSTEMS

摘要

A photoelectric sensing system (11-20) (A) having a dual function capability for monitoring an object or objects to provide an indication of light contrast levels appearing on the object or objects and to provide an indication within a permissible range of the quality of the reflected light from the object or objects to provide an indication of whether the monitored object or objects possess a desired physical property such as color, shape, pattern, position, opacity or reflectivity. An LED bargraph display (C) is preset to provide a visual indication of when the reflected light from the monitored object or objects indicates that that object or objects possess the desired physical property or properties. The signal strength of the light reflected from the monitored object or objects is processed by a logic circuit (B) fed to the bargraph display (C) so that the LED bargraph display will illuminate certain selected LED diodes.