Patent · US Expired

Image forming apparatus and image forming method for forming color images by gray-level image forming technique

US6249304A · kind A · utility

91Cited by
3References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 13, 1999
Grant dateJun 19, 2001
Priority date
Expiry dateMay 13, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/295
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

The present invention is aimed at carrying out high-precision and stable image formation using a gray-level image forming technique. In carrying out image formation by a gray-level electrophotographic process, the relationship between the layer thickness Tp of the photosensitive layer on the photosensitive member and the exposure diameter Db of a light beam emitted onto the photosensitive member is defined as 2Tp <Db, so that the charge diffusion and electric field in the photosensitive layer on the photosensitive member can be small. The maximum exposure within the exposure diameter Db is set at a value that can sufficiently reduce the differential sensitivity of the photosensitive layer, where the exposure diameter Db of the light beam is the minimum diameter at 1/e.sup.2 with respect to the peak value of the exposure distribution obtained by integrating the energy distribution of the light beam with the exposure time. In this manner, excellent gray-level image presentation can be obtained, and high-precision and stable image formation can be carried out by using a region of damping characteristics on the photosensitive member.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.