Developing device for image forming apparatus with toner recirculation operation
US5655193A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1995 |
| Grant date | Aug 5, 1997 |
| Priority date | — |
| Expiry date | Sep 18, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/0819
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A developing device capable of obviating the cohesion of toner and reducing the amount of dead toner is disclosed. The device has a developing unit accommodating a first and a second screw therein. The first and second screws extend from the toner hopper to the other longitudinal end of the developing unit in parallel to a developing roller and a supply roller. The first screw feeds toner from a toner hopper to a developing section. The second screw collects toner not contributed to development from the developing section and returns it to the first screw for recirculation. In this configuration, the collected toner and dead toner aggregating in the lower portion of the developing unit are forcibly moved to the developing section. The direction in which the screw portion of the second screw is inclined may be partly reversed to form a reverse transfer portion. Alternatively, a part of a casing adjoining the hopper may be implemented as a slant. The reverse transfer portion or the slant recirculates the toner more forcibly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.