Browse Prior Art Database

Simplex/Duplex Mode Switching in an Electrophotographic Collation Printer

IP.com Disclosure Number: IPCOM000035790D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 6 page(s) / 117K

Publishing Venue

IBM

Related People

Comeaux, RA: AUTHOR [+3]

Abstract

In an electrophotographic printer capable of selectively printing multi-sheet, collated, document sets in either the simplex or the duplex mode, paper feeding is controlled to insure that the printer switches between these two modes of operation in a manner that maximizes the output of the printer.

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At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 24% of the total text.

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Simplex/Duplex Mode Switching in an Electrophotographic Collation Printer

In an electrophotographic printer capable of selectively printing multi-sheet, collated, document sets in either the simplex or the duplex mode, paper feeding is controlled to insure that the printer switches between these two modes of operation in a manner that maximizes the output of the printer.

Fig. 1 shows this printer. The printer includes a belt photoconductor 10. Photoconductor 10 moves in a counterclockwise (CCW) direction (see arrow 11) at a constant linear speed.

Photoconductor 10 is conceptually divided into six panels upon which electrostatic latent images may be formed. Each photoconductor panel is 11 inches wide and about 16 inches long (the length dimension is measured normal to the direction of photoconductor movement 11).

In the following description, a "print cycle" is defined as the time it takes for the photoconductor to move a distance equal to one panel.

(Image Omitted)

The paper used in the printer moves through the printer with its long edge as the leading edge. Thus, 8 1/2 by 11 inch paper moves through the printer with an 11 inch edge as the leading edge. Each photoconductor panel is about 11 inches wide, i.e., 2 1/2 inches wider than the width of the latent image to be formed on the panel (i.e., 8 1/2 inches plus 2 1/2 inches).

A tachometer (not shown) is connected to be driven in synchronism with photoconductor movement. This tachometer counts from the number "0000" to the number "2640", and then resets to "0000", as the photoconductor moves the length of one 11 inch panel, i.e., one print cycle.

The printer's process stations comprise a charging station 12, a scanning laser exposure station 13, a magnetic brush developer station 14, a second-side
(i.e., even numbered page) transfer station 15, a first-side (i.e., odd numbered page) transfer station 16 and a cleaning station 17.

Operation of laser exposure station 13 will be described in connection with the "expose" function of Figs. 2 and 3.

The toner image(s) carried by a paper sheet is fused at roll fusing station 18. In the case of duplex printing, the sheet's first and second side images are fused simultaneously.

Two cut sheet paper supply bins are provided (not shown). A first of these bins cooperates with paper feed means 19, whereas a second of these bins cooperates with a similar paper feed means 20.

(Image Omitted)

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Each of the paper feeding paths includes a pick station 21. Each station 21 is defined by a pair of paper feed rollers. The leading edge of the next sheet to be used to make a print stops at pick station 21, ready to be fed to a sheet aligning station. This function is the "pick" function of Figs. 2 and 3, as will be described.

An aligner station 22 is located downstream of each of the pick stations 21. The function of aligner stations 22 is to properly align the sheet in a direction normal to the sheet's direction of movement. The sheet stops a...