Patent · US Expired

Image forming apparatus for scanning both sides of an original and producing a duplex copy

US4958187A · kind A · utility

37Cited by
9References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 9, 1988
Grant dateSep 18, 1990
Priority date
Expiry dateFeb 9, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/193
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In a duplex image forming apparatus, first and second image forming devices are arranged respectively in upstream and downstream sides of a moving direction of a transfer member. Each image forming device includes an image bearing member, a developer for forming on the image bearing member a toner image corresponding to first and second information signals, respectively, and a transfer device for transferring the respective toner images to respective sides of the transfer member. A reader is provided for reading a first side of an original and, at a point of time after reading of the first side begins, a second side of the original. The length of time required to move the transfer member from the first transfer station to the second transfer station is equal to the length of time between beginning to read the first side of the original and beginning to read the second side of the original. Advantageously, the electric polarity used to transfer the first toner image to the first side of the transfer member is opposite to that required to transfer the second toner image to the second side of the transfer member.

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