Browse Prior Art Database

PLATEN DOCUMENT TRANSPORT SHOW-AROUND DELETION

IP.com Disclosure Number: IPCOM000024789D
Original Publication Date: 1982-Feb-28
Included in the Prior Art Database: 2004-Apr-03
Document File: 2 page(s) / 123K

Publishing Venue

Xerox Disclosure Journal

Abstract

Many existing original document transports have a common flaw - "show-around". For example, over-platen document transport vacuum belts, or foam wheels all can print out (image) distinctive markings on the copy sheet if the copy paper is larger than the original, or if optical reduction is used and the document image is smaller than the copy. These markings may appear as ?ebra stripes" from multiple belts, or shadows from vacuum holes in a vacuum belt or wheel wells. Various techniques have been suggested to eliminate show-around, including shutters behind the foam wheels or measuring the document length as the document is fed (by the trail edge passing a sensor on its way onto the platen) and also measuring the copy paper length and appropriately turning on the inter-document erase lamp at the trail edge of the document image. However, the latter does not solve the problem in a manual copying mode, where the operator manually places the original on the platen. The disclosed system solves the problem in both the auto feed mode and manual mode with a sensor to detect the document trail/edge on the platen as the document is being imaged.

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Page 1 of 2

XEROX DISCLOSURE JOURNAL

PLATEN DOCUMENT TRANSPORT SHOW- AROUND DELETION U.S. Cl. 355/8 Thomas Acquaviva

Proposed Classification

Int. Cl. G03g 15/28

\,

TIMING

i

'0 1

/7

3

4

Volume 7 Number 1 January/February 1982 41

[This page contains 1 picture or other non-text object]

Page 2 of 2

PLATEN DOCUMENT TRANSPORT SHOW-AROUND DELETION (Contld)

Many existing original document transports have a common flaw - "show-around". For example, over-platen document transport vacuum belts, or foam wheels all can print out (image) distinctive markings on the copy sheet if the copy paper is larger than the original, or if optical reduction is used and the document image is smaller than the copy. These markings may appear as ?ebra stripes" from multiple belts, or shadows from vacuum holes in a vacuum belt or wheel wells. Various techniques have been suggested to eliminate show-around, including shutters behind the foam wheels or measuring the document length as the document is fed (by the trail edge passing a sensor on its way onto the platen) and also measuring the copy paper length and appropriately turning on the inter-document erase lamp at the trail edge of the document image. However, the latter does not solve the problem in a manual copying mode, where the operator manually places the original on the platen. The disclosed system solves the problem in both the auto feed mode and manual mode with a sensor to detect the document trail/edge on the platen as the document is being imaged.

As shown in Figures 1 and 2, this system will work on a conventional document handler platen transport 1 using either multiple vacuum belts, wheels or friction belts 2, as shown. A strip of retro-reflective tape or paint 3 extends along the white backing plate 4 throughout the image area. An integral infra-red LED source and sensor 5 unit is attached to the document illumination scan carriage 6 below the platen glass 7 and focused on the tape 3 sur...