Acoustic transfer assist driver system
US6157804A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2000 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Mar 22, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A piezoelectric acoustic transducer, especially for a printer photoreceptor toner transfer assist system, having a mechanical resonance varying over a substantial frequency range, is driven by a driver circuit having an automatically variable frequency electrical power output. The driver circuit initially automatically slowly sweeps over a wide frequency range encompassing the resonance range of the transducer until the resonant frequency is detected from the electrical impedance change of the transducer at resonance. The driver circuit then automatically switches to a frequency control with a phase lock loop system responsive to the phase of the transducer voltage and current, to hold and maintain the driver circuit output at the varying resonant frequency of the transducer. A small frequency range rapid dithering of the driver circuit frequency may be additionally provided above and below the resonant frequency of the transducer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.