Analog-digital converter for the evaluation of the output signal of an optoelectronic sensor element

US4338515A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Heiner Herbst · Haar, DE
• Hans-Jorg Pfleiderer · Zorneding, DE

Key dates

• Filing date: Jul 11, 1980
• Grant date: Jul 6, 1982
• Expiry date: Jul 11, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C3/085
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An analog-digital converter is disclosed which monitors an output signal of an optoelectronic sensor element for the attainment or non-attainment of a reference charge, whereupon switchover occurs from one logic signal to the other. An exclusion to a large extent of parameter or characteristic tolerance effects on the result of the evaluation is achieved. For this purpose, the converter contains an inverter, the input of which is connected via a reset transistor with a constant voltage source and which is connected via a potential barrier defining transistor with the output of the sensor element. The converter shows no dependence upon fluctuations of the inverter. Applications include distance measuring devices, and photographic and electronic cameras.