Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Multi-Feed Sensor of Auto Document Feeder

IP.com Disclosure Number: IPCOM000116289D
Original Publication Date: 1995-Aug-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Nishimoto, A: AUTHOR

Abstract

Disclosed is a device of finding multi-feed error of auto document feeder which is installed in printer, scanner or copy machine. The document passes between LED and photo diode Sensor (shown in Fig. 1). The output of Sensor depends on the strength of light through document from LED. So, the output varies if fed document is single or more. With this difference of output, multi-feed error is detected.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 91% of the total text.

Multi-Feed Sensor of Auto Document Feeder

      Disclosed is a device of finding multi-feed error of auto
document feeder which is installed in printer, scanner or copy
machine.  The document passes between LED and photo diode Sensor
(shown in Fig. 1).  The output of Sensor depends on the strength of
light through document from LED.  So, the output varies if fed
document is single or more.  With this difference of output,
multi-feed error is detected.

      Usually, LED and Sensor are fixed (shown in Fig. 3).  In this
disclosed device, the Sensor moves according to the thickness of fed
documents.  Therefore, the difference of output is larger than the
usual type.  Then, the confidence of judgment is improved against
paper dust or other aging stress.

      Figs. 1 and 2 show this device operation.  Fig. 1 shows right
situation that single document is fed.  Fig. 2 shows error situation
that multi documents are fed.  Separate plate moves wider than right
situation.  It pushes down leaf spring on which Sensor is set.
Distance between LED and Sensor becomes far and the axis of Sensor
leans.  So, the output of Sensor decreases more than usual type
(shown in Fig. 3).

      When too many documents rush into separate point, they can not
pass that point and a jam occurs.  The usual type can not sense that
and continues to rotate rollers until time-out error is recognized.
Then, documents tend to be damaged.  This device can detect that
because the pla...