Patent · US Expired

Optoelectronic circuit

US4750838A · kind A · utility

15Cited by

1References

13Claims

0Family size

Assignee

Agfa-Gevaert NV · BE

Inventors

Alfons J. De Wolf · Ranst, BE
Robert Janssens · Geel, BE

Key dates

Filing date	Oct 20, 1986
Grant date	Jun 14, 1988
Priority date	—
Expiry date	Oct 20, 2006

Classification

Technology area (CPC G)Physics
CPC primaryG03G2215/00042
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

An optoelectric circuit for measuring the different optical densities of an image carrier, a toned test patch in an otherwise untoned imaging area of a photoconductor surface in a xerographic apparatus, wherein a LED (46) irradiates a test area of the surface, a phototransistor (47) receives radiation reflected from the text area, an amplifier (51) amplifies the output signal of the phototransistor, the LED is driven by the amplified output current of the phototransistor, and the current through the LED is used as a measure of the optical density.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.