Reduction of banding and mottle in electrophotographic systems
US6885833B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2002 |
| Grant date | Apr 26, 2005 |
| Priority date | — |
| Expiry date | Aug 3, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00054
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A mechanism and process for detecting mottle or banding in a developed electrophotographic image. Within an electrophotographic reproduction apparatus 10, a photoconductor is used for receiving and developing a latent image. The photoconductor traverses a path that passes a charging station 28, an exposure station 34, a toning station 38, and a transfer station 46. Either a densitometer 76 for measuring the density of the developed image on the photoconductor, or an electrometer 50a or 50b for detecting the voltage of the image on the photoconductor, detects mottle or banding on the developed image. The densitometer 76 or electrometer 50a or 50b has an aperture small enough to detect mottle or banding with wavelengths perceptible by human eyes. A logic and control unit 24 averages the image density or voltage measurements, calculates the variations of the measurements about the average and the periodicities of the measurements, and if the variations or periodicities indicate mottle or banding is present, changes the operation of one or more stations to reduce mottle or banding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.