Piezoelectric sensor for in-situ monitoring of electrostatographic developers
US5532802A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1995 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Jan 13, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0848
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A toner mass sensor includes a piezoelectric crystal having a resonant frequency, an electrode on a first face of the crystal, an electrically conductive lead connecting the first face of the crystal to an electrical contact point in the vicinity of a second side of the crystal, and a casing closed at one end by the crystal with the first face of the crystal allowed to contact developer outside of the closed casing through the opening of the casing. The casing and crystal defines an interior which is sealed from developer in a development station, within which sealed interior the second face of the crystal is protected from contamination by developer. The electrode is wrapped around the edge of the crystal to be accessible from the second side of the crystal, and the electrode is a metal; preferably aluminum. The interior of the casing is closed by a base member which carries an electrical circuit. The casing is cylindrical, and an elastomeric, electrical insulator gasket around the crystal seals the interior of the casing to inhibit contamination of the interior of the casing by developer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.