Device for forming a developer film
US4528937A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1984 |
| Grant date | Jul 16, 1985 |
| Priority date | — |
| Expiry date | Nov 23, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y15/00
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A device for forming a toner film for use in developing an electrostatic latent image on an image bearing member, such as photosensitive member, is provided. A developing sleeve is rotatably provided and a magnet roll is also rotatably provided inside of the sleeve for magnetically attracting a blade of magnetic material to the outer peripheral surface of the sleeve thereby causing the toner carried on the sleeve to be formed into a film of desired thickness and charge. The magnet roll is formed with a plurality of magnetic poles elongated axially and arranged along the periphery of the roll in alternating polarities. Thus, the magnetic attractive force applied by the magnet roll to the blade changes periodically. In the present invention, the frequency of alternating magnetic field applied to the blade is set to be larger than the first order resonant frequency of the blade, thereby allowing to maintain the applied magnetic force as constant as possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.