AC corona charger for an electrostatographic reproduction apparatus
US6134095A · kind A · utility
Inventors
Key dates
| Filing date | Dec 17, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Dec 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0291
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A particularly configured aperiodic grid for a grid-controlled AC corona charger for uniformly charging a dielectric member, of an electrostatographic reproduction apparatus, moving along a travel path in operative relation to the corona charger. The corona charger includes an insulating housing and an electrically biased grid, in which the grid transparency is larger than a nominal transparency at the upstream edge of the charger grid, transparency is nominal at the center of the grid, and transparency is smaller than nominal at the downstream edge of a charger grid. The invention, which has been demonstrated for negative primary charging, preferably uses a trapezoidal AC waveform having a DC offset for corona excitation, and may be practiced over a large range of process speeds. The invention is also practiced using trapezoidal waveforms having negative duty cycles in the range 50% (conventional AC) to 90% (negative DC). The range of the variation in grid transparency from the upstream grid edge to the downstream grid edge is far greater than in prior art commercial machines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.