Browse Prior Art Database

Optical Reader

IP.com Disclosure Number: IPCOM000093889D
Original Publication Date: 1966-Mar-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 22K

Publishing Venue

IBM

Related People

Rogers, LSA: AUTHOR [+2]

Abstract

This optical reader uses a gallium arsenide diode D as a light source and a phototransistor T as a detector. Detection is accomplished by interruption of the light indicated by the arrow from the diode D which falls upon the normally conducting phototransistor T. A feedback arrangement is provided by resistor R2 which carries the voltage at the collector of transistor T back to diode D. Capacitor C is in parallel with diode D to reduce the AC signal feedback. R1 and R3 are biasing resistors tied to a voltage V, biased so that both transistor T and diode D normally conduct.

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Optical Reader

This optical reader uses a gallium arsenide diode D as a light source and a phototransistor T as a detector. Detection is accomplished by interruption of the light indicated by the arrow from the diode D which falls upon the normally conducting phototransistor T. A feedback arrangement is provided by resistor R2 which carries the voltage at the collector of transistor T back to diode D. Capacitor C is in parallel with diode D to reduce the AC signal feedback. R1 and R3 are biasing resistors tied to a voltage V, biased so that both transistor T and diode D normally conduct.

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