Patent · US Expired

Color image forming apparatus for preventing toner image displacement on an image support

US6075547A · kind A · utility

8Cited by
4References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 8, 1998
Grant dateJun 13, 2000
Priority date
Expiry dateMay 8, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2215/0177
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A color image forming apparatus includes an image forming unit which forms a multicolor image on a second image support by sequentially transferring toner images related to a plurality of colors from a first image support to the second image support in an overlaying manner. A reference position detecting unit detects a reference mark signal every time a reference mark at a reference position on the second image support is sensed during rotation of the second image support. A laser scan start timing control unit controls a laser scan start timing for the image forming unit to start scanning the first image support by a laser beam, based on the reference mark signal. A phase error measurement unit measures a phase error between a line sync signal and the reference mark signal by counting system clocks before the laser scan start timing. A drive speed control unit adjusts a rotating speed of the second image support to a controlled speed by outputting a drive pulse to a motor which rotates the second image support, the drive speed control unit determining an ON-state period of the drive pulse depending on the phase error measurement such that a timing of detection of the reference mar…

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