Charging roller having elastic member
US6778797B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 2001 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Jan 12, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/025
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A charging device, an image forming apparatus including the charging device, an image carrier unit including the charging device and a charging roller, which faces a body to be charged and is applied with a voltage, are disclosed. The charging roller includes a metallic core and an elastic member covering the core. Films are respectively wrapped around and adhered to the opposite end portions of the elastic member. Springs press the charging roller toward a body to be charged, causing the elastic member to deform due to compression. The maximum deformation of the films, which deform along the outer periphery of the elastic member, is selected to be smaller than the thickness of each film in the radial direction of the charge roller. A gap is therefore formed between the elastic member and the body to be charged. This prevents the portion of the elastic member, which corresponds to an image forming region, other than opposite end portions from contacting the surface of the body to be charged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.