Duplex printing system

• US 20050174379A1
• Filed: 01/21/2005
• Published: 08/11/2005
• Est. Priority Date: 01/23/2004
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Printing Systems Limited (Ricoh Company Limited)
• Inventors: Mizuno, Masahiro, Inoue, Takahiro, Nakazawa, Souichi, Miyamoto, Atsushi
• Granted Patent: US 7,552,995 B2
• Time in Patent Office: Days
• US Class Current: 347/19
• CPC Class Codes: B41J 11/46 by marks or formations on the paper being fed
• CPC Class Codes: B41J 15/04 Supporting, feeding, or guiding devices; Mountings for web rolls or spindles
• CPC Class Codes: B41J 3/60 for printing on both faces of the printing material

Abstract

An operator sets a distance from the page head of an alignment mark using a mark position setting switch mounted in a duplex printing system. A first printer forms the alignment mark in a position of the distance from the page head of a web, and reports position information about the alignment mark to a second printer. The alignment mark is detected by mark detection means of the second printer. Control means performs control of a web transport speed so that a phase between generation timing of a mark detection signal which the mark detection means generates by detecting the alignment mark and control timing calculated from alignment mark position data, alignment mark interval data and a web feed control signal generated at a preset period becomes constant.

Claims

1. A duplex printing system comprising:

a first printer for forming an image on a first side of a web without a feed hole;

a second printer which is provided in a backward stage of the first printer and forms an image on a second side of the web;

a control device for transporting print data and a web transport signal indicating instruction of printing to the first printer and the second printer;

mark detection means for detecting an alignment mark formed on the web; and

image alignment control means for matching a position of the image formed on the second side with a position of the image formed on the first side of the web by controlling a transport speed of the web so as to match a phase of the web transport signal with a phase of a mark detection signal from the mark detection means, wherein

the image alignment control means has position information indicating a position in which the alignment mark is formed and calculation means for calculating timing at which the alignment mark is detected by the position information, and

the image alignment control means aligns the images based on the alignment mark detection timing calculated by the calculation means.

2. The duplex printing system according to claim 1, wherein

the first printer has mark formation means for forming the alignment mark in a previously specified position of each page of the web.

3. The duplex printing system according to claim 2, wherein

the control device instructs the first printer to form the alignment mark in a position of the position information with respect to each page of the web.

4. The duplex printing system according to claim 1, wherein

the control device reports the position information to the first and second printers.

5. The duplex printing system according to claim 3, wherein

the control device has mark position setting means capable of arbitrarily setting the position information.

6. The duplex printing system according to claim 4, wherein

the control device has mark position setting means capable of arbitrarily setting the position information.