Copyright © Philip M. Parker, INSEAD. Terms of Use.
| Year | Description |
| 1998 | Invention patented by John W. May, Dean R. Smith, David M. Zacher, Bonnie A. Maye, Dennis A. Kenyon, and Martin J. Pernesky on December 16th, 1998. 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: selected by the editor from original sources. | |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
