Patent · US Expired

Image forming apparatus

US6122075A · kind A · utility

25Cited by
3References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 15, 1997
Grant dateSep 19, 2000
Priority date
Expiry dateOct 15, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/4078
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

According to this invention, a controlled image quality is obtained without adjustment with respect to a short range of environmental changes in temperature, humidity and the like, and feedback control is easily performed for controlled variables over a long range to cope with changes with time, and the like. In the two-component non-contact development, the image density becomes stable irrespective of any environmental changes in temperature, humidity and the like when the developing bias AC voltage in the developer unit is a predetermined value. At the same developing bias AC voltage, when the rotating speed of the development roll is changed, the image density varies While making the developing bias AC voltage and the development roller rotating speed variable at the same time, a reference pattern is prepared on a banner sheet to measure the image density with an optical sensor. From the measured results, the stable value for the developing bias AC voltage is determined, and further the rotating speed of the development roller at which desired image quality density is attained, is determined.

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