Apparatus for sensing deterioration of developing substance including ferromagnetic carrier and non-magnetic toner particles
US4195260A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1978 |
| Grant date | Mar 25, 1980 |
| Priority date | — |
| Expiry date | Feb 6, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S222/01
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Deterioration of a dry developing substance causes toner particles to be so strongly adhered to carrier particles that they cannot be readily separated therefrom. The present apparatus comprises means for applying a predetermined electrostatic or air suction force to the developer to readily remove toner therefrom except for spent toner particles strongly adhered to the carrier particles. The toner density, or the ratio of toner to carrier particles, is then measured electromagnetically or optically and compared to a reference value. The developer deterioration determines what proportion of toner will be removed from the developer by said force and thereby the subsequently sensed toner density. The higher the sensed toner density, the greater the degree of deterioration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.