U.S. patent application number 11/805780 was filed with the patent office on 2008-11-27 for method of operating a document feeding mechanism to detect and recover from a multi-feed condition and an apparatus therefor.
This patent application is currently assigned to NCR Corporation. Invention is credited to Frank B. Dunn.
Application Number | 20080290584 11/805780 |
Document ID | / |
Family ID | 39736918 |
Filed Date | 2008-11-27 |
United States Patent
Application |
20080290584 |
Kind Code |
A1 |
Dunn; Frank B. |
November 27, 2008 |
Method of operating a document feeding mechanism to detect and
recover from a multi-feed condition and an apparatus therefor
Abstract
A method is provided of operating a document feeding mechanism
having a document feed path which extends through a nip defined
between an advance roller disposed on one side of a document feed
path and a retard roller disposed on an opposite side of the
document feed path. The method comprises detecting a multi-feed
condition in which a first document and a second document
overlapping the first document have been fed through the nip from
an upstream end of the document feed path to a downstream end of
the document feed path, and controlling operation of the advance
roller and the retard roller such that the second document is
driven backwards through the nip to allow the first document to be
fed through the nip by itself in a non-overlapping manner without
any human intervention.
Inventors: |
Dunn; Frank B.; (Waterloo,
CA) |
Correspondence
Address: |
Michael Chan;Intellectual Property Section, Law Department
NCR Corporation, 1700 South Patterson Blvd.
Dayton
OH
45479-0001
US
|
Assignee: |
NCR Corporation
|
Family ID: |
39736918 |
Appl. No.: |
11/805780 |
Filed: |
May 24, 2007 |
Current U.S.
Class: |
271/10.02 |
Current CPC
Class: |
B65H 2553/30 20130101;
B65H 2701/1912 20130101; B65H 2513/41 20130101; B65H 2513/514
20130101; B65H 2513/412 20130101; B65H 2513/412 20130101; B65H 7/06
20130101; B65H 7/12 20130101; B65H 5/062 20130101; B65H 2511/524
20130101; B65H 2513/514 20130101; B65H 2513/41 20130101; B65H
2513/512 20130101; B65H 2220/02 20130101; B65H 2220/01 20130101;
B65H 2220/02 20130101; B65H 2220/02 20130101; B65H 2220/11
20130101; B65H 2220/02 20130101; B65H 2301/44514 20130101; B65H
2513/512 20130101; B65H 2511/524 20130101 |
Class at
Publication: |
271/10.02 |
International
Class: |
B65H 7/06 20060101
B65H007/06 |
Claims
1. A method of operating a document feeding mechanism having a
document feed path which extends through a nip defined between an
advance roller disposed on one side of a document feed path and a
retard roller disposed on an opposite side of the document feed
path, the method comprising: detecting a multi-feed condition in
which a first document and a second document overlapping the first
document have been fed through the nip from an upstream end of the
document feed path to a downstream end of the document feed path;
and controlling operation of the advance roller and the retard
roller such that the second document is driven backwards through
the nip to allow the first document to be fed through the nip by
itself in a non-overlapping manner without any human
intervention.
2. A method according to claim 1, further comprising: after the
first document has been fed through the nip by itself, controlling
operation of the advance roller and the retard roller such that the
second document is fed through the nip by itself in a
non-overlapping manner without any human intervention.
3. A method of operating a document feeding mechanism having a
document feed path which extends through a nip defined between an
advance roller disposed on one side of a document feed path and a
retard roller disposed on an opposite side of the document feed
path, the method comprising: detecting a multi-feed condition in
which a first document and a second document overlapping the first
document have been fed through the nip from an upstream end of the
document feed path to a downstream end of the document feed path;
halting operation of the advance roller when the multi-feed
condition is detected; and reversing direction of rotation of the
retard roller when the multi-feed condition is detected such that
the second document which is adjacent to the retard roller is
driven backwards through the nip from the downstream end of the
document feed path to the upstream end of the document feed path
while the first document which is adjacent to the halted advance
roller is maintained in the nip between the advance roller and the
retard roller.
4. A method according to claim 3, further comprising: after the
second document has been driven backwards completely through the
nip, continuing operation of the advance roller such that the first
document continues to be fed through the nip from the upstream end
of the document feed path to the downstream end of the document
feed path.
5. A method according to claim 4, further comprising: after the
first document has been fed through the nip from the upstream end
of the document feed path to the downstream end of the document
feed path, continuing operation of the advance roller such that the
second document is fed through the nip from the upstream end of the
document feed path to the downstream end of the document feed
path.
6. A document feeding apparatus comprising: an advance roller
disposed on one side of a document feed path; a retard roller
disposed on an opposite side of the document feed path and facing
the advance roller to form a nip therebetween; a sensor for (i)
detecting a multi-feed condition in which a first document and a
second document overlapping the first document have been fed
through the nip from an upstream end of the document feed path to a
downstream end of the document feed path, and (ii) providing a
sensor signal indicative of the multi-feed condition; a controller
for (i) providing a first control signal to halt operation of the
advance roller when the sensor signal indicative of the multi-feed
condition is detected, and (ii) providing a second control signal
to reverse direction of rotation of the retard roller when the
sensor signal indicative of the multi-feed condition is detected
such that the second document which is adjacent to the retard
roller is driven backwards through the nip from the downstream end
of the document feed path to the upstream end of the document feed
path while the first document which is adjacent to the halted
advance roller is maintained in the nip between the advance roller
and the retard roller.
7. A document feeding apparatus according to claim 6, wherein after
the second document has been driven backwards completely through
the nip, the controller provides a third control signal to continue
operation of the advance roller such that the first document
continues to be fed through the nip from the upstream end of the
document feed path to the downstream end of the document feed
path.
8. A document feeding apparatus according to claim 7, wherein after
the first document has been fed through the nip from the upstream
end of the document feed path to the downstream end of the document
feed path, the controller provides a fourth control signal to
continue operation of the advance roller such that the second
document is fed through the nip from the upstream end of the
document feed path to the downstream end of the document feed
path.
9. A document feeding apparatus according to claim 8, wherein the
third control signal and the fourth control signal are
substantially the same.
10. A document feeding apparatus according to claim 6, wherein the
sensor comprises an ultrasonic-type of sensor.
Description
BACKGROUND
[0001] The present invention relates to document feeding along a
document feed path, and is particularly directed to a method of
operating a document feeding mechanism to detect and recover from a
multi-feed condition and an apparatus therefor.
[0002] Many different types of document feeding mechanisms are
known. From time to time, a multi-feed document condition occurs in
which more than one document is fed along a document transport path
when only one document should have been fed along the document feed
path. The occurrence of a multi-feed condition usually causes an
undesirable result. For example, in an automated teller machine
(ATM) type of application in which banknotes are being dispensed, a
multi-feed condition of a banknote will result in a loss to the ATM
owner. In another type of ATM type of application in which checks
are being deposited, a multi-feed condition of a deposited check
will result in a missing deposit item. It would be desirable to
provide a document feeding mechanism in which multi-feed conditions
are not only detected but are also recovered from.
SUMMARY
[0003] In accordance with one embodiment of the present invention,
a method is provided of operating a document feeding mechanism
having a document feed path which extends through a nip defined
between an advance roller disposed on one side of a document feed
path and a retard roller disposed on an opposite side of the
document feed path. The method comprises detecting a multi-feed
condition in which a first document and a second document
overlapping the first document have been fed through the nip from
an upstream end of the document feed path to a downstream end of
the document feed path, and controlling operation of the advance
roller and the retard roller such that the second document is
driven backwards through the nip to allow the first document to be
fed through the nip by itself in a non-overlapping manner without
any human intervention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] In the accompanying drawings:
[0005] FIG. 1 is a schematic view of a document feeding mechanism
constructed in accordance with one embodiment of the present
invention;
[0006] FIGS. 2-11 are views similar to FIG. 1 and showing parts in
different positions.
DETAILED DESCRIPTION
[0007] The present invention is directed to a method of operating a
document feeding mechanism to detect and recover from a multi-feed
condition and an apparatus therefor. The specific use and
construction of the document feeding mechanism may vary. By way of
example, a document feeding mechanism 10 constructed in accordance
with one embodiment of the present invention is illustrated in FIG.
1.
[0008] The document feeding mechanism 10 has an upstream end 12, a
downstream end 14, and a document feed path 16 extending between
the upstream end and the downstream end. The document feeding
mechanism 10 includes an advance roller 32 which is adjacent to the
document feed path 16. The advance roller 32 has a longitudinal
central axis and an outer circumferential surface 33. The advance
roller 32 is rotatably mounted on a first shaft 34 for rotation
about its longitudinal central axis.
[0009] The document feeding mechanism 10 further includes a retard
roller 36 which is adjacent to the document feed path 16 and lies
opposite the advance roller 32. The retard roller 36 has a
longitudinal central axis and an outer circumferential surface 37.
The retard roller 36 is rotatably mounted on a second shaft 38 for
rotation about its longitudinal central axis. A nip 39 is defined
between the outer circumferential surface 33 of the picker roller
32 and the outer circumferential surface 37 of the retard roller
36.
[0010] The document feeding mechanism 10 also includes a sensor 40
for detecting a multi-feed condition in which more than one
document has been fed through the nip 39 along the document feed
path 16. The sensor 40 may be of the ultrasonic type, for example.
A controller 50 monitors and receives a sensor signal via line 52
from the sensor 40. The controller 50 provides a control signal via
line 54 to the advance roller 32 to control operation of the
advance roller. The controller 50 also provides a control signal
via line 56 to the retard roller 36 to control operation of the
retard roller.
[0011] During normal operation of the document feeding mechanism 10
(as shown in FIG. 1), the controller 50 controls the advance roller
32 to rotate about its longitudinal central axis in the clockwise
direction (as viewed looking at FIG. 1). The controller 50 controls
the retard roller 36 to rotate about its longitudinal central axis
also in the clockwise direction. As the advance roller 32 and the
retard roller 36 both rotate in the clockwise direction, the
rollers co-operate to feed a first document 60 through the nip 39
along the document feed path 16. More specifically, due to
frictional engagement between the outer circumferential surface 33
of the advance roller 32 and the outer circumferential surface 37
of the retard roller 36, the first document 60 is transported from
the upstream end 12 of the document feed path 16 towards the
downstream end 14 along the document feed path for further handling
and processing at the downstream end of the document feed path.
[0012] When the first document 60 is the only document fed through
the nip 39 (such as shown in FIG. 1), the sensor 40 does not detect
a multi-feed condition. Accordingly, the sensor 40 does not provide
a signal on line 52 which is indicative of a multi-feed condition.
Since the controller 50 does not receive a signal on line 52
indicative of a multi-feed condition, the controller continues to
provide signals on lines 54, 56 to rotate the advance roller 32 in
the clockwise direction and the retard roller 36 in the clockwise
direction. After the first document 60 has been normally fed
through the nip 39, the advance roller 32 and the retard roller 36
continue to feed a second document 62 (as shown in FIG. 2) through
the nip 39 in the same manner as the first document 60 was normally
fed through the nip.
[0013] However, when a multi-feed condition occurs in which both
the first and second documents 60, 62 pass through the nip 39 in
overlapping manner (such as shown in FIG. 3), the sensor 40 detects
the occurrence of the multi-feed condition and provides a signal on
line 52 indicative thereof. In response to receiving the signal on
line 52 from the sensor 40, the controller 50 provides a control
signal on line 54 to the advance roller 32 to halt rotation of the
advance roller in the clockwise direction (as shown in FIG. 4). At
the same time, the controller 50 continues providing the same
previous signal on line 56 to the retard roller 36 so that the
retard roller continues rotating in the clockwise direction.
[0014] When the advance roller 32 is halted and the retard roller
36 continues to rotate in the clockwise direction, the second
document 62 is driven backwards (i.e., to the right as viewed
looking at FIG. 4) through the nip 39 towards the upstream end 12
of the document feed path 16. After the second document 62 has been
driven back completely through the nip 39 (as shown in FIG. 5), the
controller 50 again provides a control signal on line 54 to control
the advance roller 32 to rotate in the clockwise direction. This
rotation of the advance roller 32 again in the clockwise direction
moves the first document 60 (which is now by itself between the
advance roller 32 and the retard roller 36) through the nip 39
towards the downstream end 14 of the document feed path 16. After
the first document 60 has moved completely through the nip 39
towards the downstream end 14 of the document feed path 16 (as
shown in FIG. 6), the advance roller 32 and the retard roller 36
co-operate to feed the next document (i.e., the second document 62
in this case) through the nip 39 towards the downstream end of the
document feed path. The second document 62 is also now fed by
itself through the nip 39 towards the downstream end 14 of the
document feed path 16.
[0015] As the second document 62 is being driven backwards through
the nip 39 as just described hereinabove, it is recognized that the
controller 50 will detect absence of the multi-feed condition
signal from the sensor 40 before the second document 62 is actually
driven back completely through the nip 39. To ensure that the
second document 62 has been driven back completely through the nip
39 before the advance roller 32 is again activated to rotate in the
clockwise direction, the controller 50 is programmed with a
sufficient time delay in responding to removal of the multi-feed
condition signal on line 52 from the sensor 40 as an input signal.
This time delay will provide sufficient time for the second
document 62 to be driven back completely through the nip 39 before
the controller 50 provides the control signal on line 54 to again
control the advance roller 32 to rotate in the clockwise
direction.
[0016] It should be apparent that the operation of the document
feeding mechanism 10 described hereinabove enables a multi-feed
condition to be not only detected but also to be automatically
corrected without any human intervention. Accordingly, a human
operator is not needed to halt operation of the document feeding
mechanism 10 to remove documents from the document feed path 16 to
clear a multi-feed condition which has occurred along the document
feed path.
[0017] Although the above description describes two overlapped
documents (i.e., the first document 60 and the second document 62)
passing through the nip 39, it is conceivable that more than two
overlapped documents could pass through the nip 39. For example, as
shown in FIG. 7, if three overlapping documents 70, 72, 74 have
passed through the nip 39 and sensed by the sensor 40, then the
advance roller 32 is controlled to halt rotation in the clockwise
direction and the retard roller 36 is controlled to continue
rotating in the clockwise direction. The advance roller 32 is
halted and the retard roller 36 rotates in the clockwise direction
until the document 74 has been driven backwards completely through
the nip (as shown in FIG. 8). However, since the sensor 40 still
detects a multi-feed condition in FIG. 8, the advance roller 32
remains halted and the retard roller 36 continues rotating in the
clockwise direction until the document 72 has also been driven
backwards completely through the nip 39 (as shown in FIG. 9).
[0018] After the two documents 72, 74 have been driven backwards
completely through the nip 39 as shown in FIG. 9, the advance
roller 32 is controlled to again rotate in the clockwise direction
to feed the document 70 (which is now by itself between the advance
roller 32 and the retard roller 36) through the nip 39 towards the
downstream end 14 of the document feed path 16 (as shown in FIG.
10). Also as shown in FIG. 10, after the document 70 has been fed
completely through the nip 39, the next document (i.e., the
document 72) is fed through the nip. Accordingly, it should be
apparent that the document feeding mechanism 10 is capable of not
only detecting but also correcting a multi-feed condition in which
more than two overlapping documents have passed through the nip 39,
without any human intervention.
[0019] Further, it is conceivable that co-operation of the halting
of the advance roller 32 and the reversing of the retard roller 36
may not result in driving multi-fed documents (such as the two
documents 72, 74 shown in FIG. 7) back behind the nip 39 so that
documents can be separated in the manner as described hereinabove.
If this should occur, then the advance roller 32 could be driven to
rotate in the reverse direction (i.e., in the counter-clockwise
direction as viewed looking at FIG. 7) so that the entire bunch of
documents (i.e., all three documents 70, 72, 74 in this example) is
driven and fed back behind the nip 39 as shown in FIG. 11. After
the entire bunch of documents has been fed behind the nip 39 as
shown in FIG. 11, the advance roller 32 is controlled to again
rotate in the clockwise direction in an effort to feed the
documents 70, 72, 74 one by one through the nip. By driving and
feeding the entire bunch of documents behind the nip 39 as shown in
FIG. 11, the retard roller 36 is provided with a second chance to
catch the edge of the underlying documents (i.e., the documents 72,
74 in this example) so that a clean separation of all three
documents can be achieved.
[0020] The particular arrangements disclosed are meant to be
illustrative only and not limiting as to the scope of the
invention. From the above description, those skilled in the art to
which the present invention relates will perceive improvements,
changes and modifications. Numerous substitutions and modifications
can be undertaken without departing from the true spirit and scope
of the invention. Such improvements, changes and modifications
within the skill of the art to which the present invention relates
are intended to be covered by the appended claims.
* * * * *