Multiple copy and transparency detector with illumination control
US4577096A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1983 |
| Grant date | Mar 18, 1986 |
| Priority date | — |
| Expiry date | Aug 15, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00721
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A sheet detector having an emitter (lamp), detector (phototransistor), operational amplifier and an RC network. As contamination is deposited on the emitter or detector, a feedback loop provides more drive to the lamp providing sufficient drive to hold the emitter of the phototransistor at its desired stage. As a first copy paper is passed between the emitter and detector, the RC network of a common mode operational amplifier detects a change and generates an output. As a subsequent sheet enters the system, the transmissibility abruptly changes again causing the common mode operational amplifier to provide a subsequent pulse indicating the presence of a multiple feed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.