Patent · US Expired

Image forming apparatus

US6655774B2 · kind B2 · utility

4Cited by
4References
30Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 26, 2001
Grant dateDec 2, 2003
Priority date
Expiry dateDec 26, 2021

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2201/04794
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A high quality image is obtained by decreasing color aberration and image blurring accompanying the temperature rise in an image forming apparatus while escaping the rise of costs and the increase of the size thereof. A DSP samples a surface image of a transferring belt or a transferring material at a fixed period with a CMOS sensor, and the DSP takes the sampled image into an inner buffer and stores it in an image memory. Next, the DSP performs the comparison operation of the image taken in by the sampling and an image on the image memory that has been sampled at last sampling in advance with an image comparison processing part. Next, the DSP detects a shifted amount of the image in the conveyance direction of the transferring material or the transferring belt. Thereby, it is introduced how many pixels of the last sampled image has shifted in the conveyance direction at the time of the next sampling, and then the movement rate is calculated on the sampling time. The DSP obtains a control rate of a transferring belt driving motor on the result of the calculated movement rate to perform the servo control of the motor.

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