Developing device having toner recycling means and toner concentration controller
US5508793A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1994 |
| Grant date | Apr 16, 1996 |
| Priority date | — |
| Expiry date | Feb 14, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G21/105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A developing device has a developing unit to develop an electrostatic latent image formed on an image carrier surface with two-component developer composed of toner and carrier, a toner recycling device to feed toner removed from the image carrier surface by a cleaner back to the developing unit so as to recycle the removed toner, a supply member for supplying fresh toner to the developing device, and a toner concentration controller to control toner concentration in accordance with the result of a comparison between a reference signal that has been set, and a toner concentration of developer determined when the magnetic permeability of developer is detected by a toner concentration detection sensor disposed in the developing device. A drive source of the developing unit and that of the toner recycling device can be individually controlled. When a reference signal for the toner concentration sensor is to be set, a forcible idling operation is started in which the toner recycling device recycles toner to the developing device without the supply of fresh toner to the developing device by the supply member. Alternatively, the reference signal can be set when both the recycling device …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.