Browse Prior Art Database

CONSTANT VELOCITY TRANSPORT

IP.com Disclosure Number: IPCOM000025226D
Original Publication Date: 1984-Feb-29
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 68K

Publishing Venue

Xerox Disclosure Journal

Abstract

A document transport 1 suitable for transporting individual document 7 at a constant velocity passed an optics system in a copier is shown in the accompanying figure. The document transport consists of a glass platen 10, a scan slit 12, a first nip 14 defined by driven roller 3 and idler roller 4, and a second nip 16 defined by driven roller 5 and the platen. A timing belt 6 drives both roller 3 and 5 at the same time. In operation, the document 7 enters the first nip 14, moves over the scan slit 12 in the direction of arrow 18, and then enters the second nip 16. Prior to entry of the document 7 into nip 14, driven roller 5 is lifted off the platen. Once the lead edge of document 7 has entered the vicinity of second nip 16, driven roller 5 is lowered into contact with the document to form nip 16 with the document already therein.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 81% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

CONSTANT VELOCITY TRANSPORT Proposed Victor Castro-Hahn Classification

U.S. CI. 355/14R Int. C1. G03g 15/00

6

5

I

A document transport 1 suitable for transporting individual document 7 at a constant velocity passed an optics system in a copier is shown in the accompanying figure. The document transport consists of a glass platen 10, a scan slit 12, a first nip 14 defined by driven roller 3 and idler roller 4, and a second nip 16 defined by driven roller 5 and the platen. A timing belt 6 drives both roller 3 and 5 at the same time. In operation, the document 7 enters the first nip 14, moves over the scan slit 12 in the direction of arrow 18, and then enters the second nip 16. Prior to entry of the document 7 into nip 14, driven roller 5 is lifted off the platen. Once the lead edge of document 7 has entered the vicinity of second nip 16, driven roller 5 is lowered into contact with the document to form nip 16 with the document already therein.

Without lifting driven roller 5 out of contact with the platen before the document enters the first nip, the nip friction coefficient would decrease by approximately a factor of ten as soon as the document entered the second nip 16. Similarly, the driving torque would decrease by the same factor and this sudden change in driving torque changes the velocity of the document resulting in a smearing of part of the latent image.

Alternatively, instead of lifting driven roller 5, driven roller may be suppor...