Electrophotographic device with improved bead pickoff arrangement
US4829338A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1988 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Jan 29, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/095
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A bead pickoff device for removal of carrier beads adhering to a charge retentive surface subsequent to development of an electrostatic latent image with a developer mix including toner and carrier beads. A stationary magnet member supported within a rotating non-magnetic shell includes a permanent magnet supported in a ferromagnetic strip is provided with first and second sides disposed at an angle in the range of 70.degree. to 110.degree. with respect to each other. The first long side is supported with angled surface free end adjacent the charge retentive surface. The stationary magnet is seated on the second side, spaced from the first. The magnetic field is concentrated in the space between the magnet and the first side to provide an increased bead pickoff force at the charge retentive surface, while the field is attenuated to reduce the force of attraction on the beads as they move away from the charge retentive surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.