Image forming apparatus and cartridge having charging roller
US10310402B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2018 |
| Grant date | Jun 4, 2019 |
| Priority date | — |
| Expiry date | Jun 13, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/021
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus includes a photosensitive member having a surface having elastic deformation power of 47% or more, a charging roller forming a nip between itself and the photosensitive member, and an image forming portion. When a nip region corresponding to the nip is formed and then an area of independent contact portions between the charging member and a measuring contact member is measured, the following relationship is satisfied: (contact width X)×(Contact area ratio α)≤0.1, where a length from a position of one end to a position of the other end of the nip region with respect to a direction perpendicular to a longitudinal direction of the charging roller is the contact width X, and a ratio of a sum of areas of the independent contact portions to an entire area of a measuring region is the contact area ratio α.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.