U.S. patent application number 16/776577 was filed with the patent office on 2020-05-28 for feeding device and sheet processing device with the same.
This patent application is currently assigned to DUPLO SEIKO CORPORATION. The applicant listed for this patent is DUPLO SEIKO CORPORATION. Invention is credited to Hiroki IKESHITA, Masayasu MATSUMOTO.
Application Number | 20200165087 16/776577 |
Document ID | / |
Family ID | 63720451 |
Filed Date | 2020-05-28 |
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United States Patent
Application |
20200165087 |
Kind Code |
A1 |
IKESHITA; Hiroki ; et
al. |
May 28, 2020 |
FEEDING DEVICE AND SHEET PROCESSING DEVICE WITH THE SAME
Abstract
A feeding device includes a suction feeding unit having a belt
for feeding a sheet in a suction state and a belt driving unit, a
sheet detection sensor, and a control unit. The control unit
controls the belt drive unit so as to feed the sheet in a feeding
direction at a first speed. If the sheet does not arrive at the
sheet detection sensor, the control unit controls the belt drive
unit so as to execute a low-speed feeding of moving the belt in the
feeding direction at a second speed lower than the first speed or
so as to execute a reverse feeding of moving the belt in a reverse
feeding direction opposite to the feeding direction.
Inventors: |
IKESHITA; Hiroki;
(Kinokawa-shi, JP) ; MATSUMOTO; Masayasu;
(Kinokawa-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DUPLO SEIKO CORPORATION |
Kinokawa-shi |
|
JP |
|
|
Assignee: |
DUPLO SEIKO CORPORATION
Kinokawa-shi
JP
|
Family ID: |
63720451 |
Appl. No.: |
16/776577 |
Filed: |
January 30, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16104241 |
Aug 17, 2018 |
|
|
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16776577 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2220/01 20130101;
B65H 2220/01 20130101; B65H 2220/02 20130101; B65H 2220/01
20130101; B65H 2220/01 20130101; B65H 2220/02 20130101; B65H
2220/02 20130101; B65H 2513/41 20130101; B65H 2511/515 20130101;
B65H 3/128 20130101; B65H 7/06 20130101; H04N 1/00729 20130101;
B65H 2513/10 20130101; H04N 1/0061 20130101; B65H 2515/10 20130101;
B65H 2511/10 20130101; B65H 2511/414 20130101; B65H 2513/41
20130101; B65H 3/124 20130101; B65H 2511/414 20130101; B65H
2511/242 20130101; B65H 2515/10 20130101; B65H 2511/10 20130101;
B65H 2511/242 20130101; B65H 2513/10 20130101; B65H 2511/515
20130101 |
International
Class: |
B65H 3/12 20060101
B65H003/12; B65H 7/06 20060101 B65H007/06; H04N 1/00 20060101
H04N001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 7, 2017 |
JP |
2017-172346 |
Claims
1. A feeding device comprising: a suction feeding unit having a
belt for feeding a sheet on a feeding table along a feeding path in
a suction state, and a belt drive unit for moving said belt; a skew
detection sensor that is provided in said feeding path in a
downstream of said suction feeding unit and detects presence or
absence of a skewed state of said sheet; and a control unit for
controlling said belt drive unit, wherein said control unit
controls said belt drive unit so as to execute a first operation of
moving said belt in a feeding direction at a first speed by a belt
feeding amount capable of feeding said sheet from said feeding
table to said skew detection sensor, and wherein said control unit,
if the skewed state of said sheet is detected by said skew
detection sensor, controls said belt drive unit so as to execute a
reverse feeding of moving said belt in a reverse feeding direction
opposite to said feeding direction by a belt reverse feeding amount
capable of feeding said sheet detected as being in the skewed state
up to said feeding table.
2. The feeding device according to claim 1, wherein said control
unit controls said belt drive unit so as to repeat said first
operation after executing said reverse feeding or so as to repeat a
second operation of moving said belt in said feeding direction at a
second speed lower than said first speed after executing said
reverse feeding.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S.
Ser. No. 16/104,241, which was filed on Aug. 17, 2018, and which
claims the benefit of priority for Japanese Patent Application No.
2017-172346 filed Sep. 7, 2017. The subject matter of Japanese
Patent Application No. 2017-172346 and U.S. Ser. No. 16/104,241 is
incorporated herein in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present disclosure relates to a feeding device for
feeding a sheet and a sheet processing device with the same feeding
device.
Description of the Prior Art
[0003] A sheet processing device has been well known in which a
feeding device separates a sheet one by one by air suction from a
sheet bundle stacked on a feeding table and feeds the sheet to
execute a variety of processings on the sheet being fed, such as
cutting and creasing. An example of such a sheet processing device
has been disclosed in Japanese Unexamined Patent Application
Publication No. 2015-196571.
SUMMARY OF THE INVENTION
[0004] In the device disclosed in Japanese Unexamined Patent
Application Publication No. 2015-196571, a suction force in feeding
a sheet is controlled by moving a closing member so that a suction
opening part at a predetermined location functions depending on a
size or thickness of the sheet. However, since a sheet state
changes due to various factors and the suction force also changes
due to changes in the sheet state, it is difficult to prevent an
abnormal state upon feeding of a sheet only by controlling the
suction force. Then, there is a problem that a complicated drive
mechanism for moving the closing member is required and further,
there is another problem that controlling of the drive mechanism is
complicated.
[0005] Accordingly, a technical problem to be solved of the present
disclosure is to provide a feeding device which, if an abnormal
state occurs upon feeding of a sheet, can easily recover the
abnormal state and a sheet processing device with the same feeding
device.
[0006] To solve the above-mentioned technical problem, there is
provided a feeding device and a sheet processing device with the
feeding device.
[0007] According to an embodiment of the present invention, there
is provided a feeding device comprises a suction feeding unit
having a belt for feeding a sheet on a feeding table along a
feeding path in a suction state, and a belt drive unit for moving
the belt; a sheet detection sensor that is provided in the feeding
path in a downstream of the suction feeding unit and detects
presence or absence of the sheet; and a control unit for
controlling the belt drive unit. The control unit controls the belt
drive unit so as to execute a first operation of moving the belt in
a feeding direction at a first speed by a belt feeding amount
capable of feeding the sheet from the feeding table to the sheet
detection sensor. If the first operation is executed and an arrival
of the sheet cannot be detected by the sheet detection sensor, the
control unit controls the belt drive unit so as to execute a
low-speed feeding of moving the belt in the feeding direction at a
second speed lower than the first speed by the belt feeding amount
or so as to execute a reverse feeding of moving the belt in a
reverse feeding direction opposite to the feeding direction by a
belt reverse feeding amount capable of feeding the sheet up to the
feeding table.
[0008] According to the present embodiment, if any abnormal state
occurs upon feeding of the sheet, the abnormal state can be easily
recovered to a normal state by feeding of the sheet with a sheet
feeding force enhanced by the low-speed feeding or by returning the
sheet by a reverse feeding finally to an original feeding start
position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more complete appreciation of the present invention and
many of the attendant advantages thereof will be readily obtained
as the same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0010] FIG. 1 is a longitudinal sectional view illustrating
schematically an entire structure of a sheet processing device
according to an embodiment of the present invention;
[0011] FIG. 2 is a block diagram showing an electrical
configuration of the sheet processing device shown in FIG. 1;
[0012] FIG. 3 is a schematic view for explaining an example of
reducing a belt reverse feeding amount in a reverse feeding
direction;
[0013] FIG. 4 is a schematic view for explaining another example of
reducing a belt reverse feeding amount in a reverse feeding
direction;
[0014] FIG. 5 is a schematic view for explaining a skew detection
of a sheet;
[0015] FIG. 6 is a flow chart for explaining a first recovery
operation according to the first embodiment;
[0016] FIG. 7 is a flow chart for explaining a reverse feeding
according to a second embodiment;
[0017] FIG. 8 is a flow chart for explaining a reverse feeding
according to a third embodiment;
[0018] FIG. 9 is a flow chart for explaining a reverse feeding
according to a fourth embodiment; and
[0019] FIG. 10 is a flow chart for explain a second recovery
operation according to a fifth embodiment.
DESCRIPTION OF THE EMBODIMENTS
[0020] Hereinafter, a feeding device 7, a sheet processing device 1
having the same feeding device 7 and a feeding method will be
described with reference to the drawings. For convenience of
description, a downstream side of a feeding direction F of a sheet
100 is called "forward" or just "downstream side" as described in
FIG. 1, etc. An upstream side of the feeding direction F of the
sheet 100 is called "backward" or just "upstream side". A reverse
direction of the feeding direction F of the sheet 100 is called
"reverse feeding direction B". An upside and a downside with
respect to a feeding path 10 are called "upside" and "downside",
respectively. A sheet width direction (horizontal direction
perpendicular to the feeding direction F) is called "left-right
direction", and the "left side" and "right side" are defined when
viewed from backward of the sheet 100. Further, according to the
present disclosure, the sheet 100 includes not only a paper sheet
but also a resin sheet.
Entire Structure of a Sheet Processing Device
[0021] FIG. 1 is a longitudinal sectional view for explaining
schematically an entire configuration of a sheet processing device
1 according to an embodiment of the present invention. The sheet
processing device 1 includes a feeding device 7, a first processing
unit 21, a second processing unit 22 and a discharge tray (not
shown). The feeding device 7 sequentially feeds a sheet one by one
in a feeding direction F along a feeding path 10 from the top of a
plurality of sheets 100 stacked in the form of a sheet bundle. The
first processing unit 21 and the second processing unit 22 operate
as a sheet processing unit to apply a predetermined processing to
the sheet 100 fed from the feeding device 7, respectively. A
plurality of feeding rollers are disposed separately in the feeding
path 10 from the feeding device 7 to the discharge tray. Each of
the feeding rollers 4 is composed of a pair of roller parts and
sequentially feeds the sheet 100 nipped by a pair of the roller
parts. A position of the sheet 100 being fed is appropriately
detected by various sensors provided in the feeding path 10.
[0022] At least the first processing unit 21 and the second
processing unit 22 are provided in the feeding path 10 in order
from the side of the feeding device 7 (i.e., from the upstream side
to the downstream side). The sheet processing device 1 may be
provided with the first processing unit 21 and the second
processing unit 22 detachably or fixedly. In case where those units
are used as an independent unit, they are configured to have a same
dimension and shape in appearance so that they can be detachably to
any installation place. Further, the first processing unit 21 and
the second processing unit 22 are provided with a first processing
motor and a second processing motor 45 as a driving means,
respectively. In the meantime, the first processing unit 21 and the
second processing unit 22 do not mean just only two sheet
processing units but are defined as a wider concept including two
or more sheet processing units. As the first processing unit 21 and
the second processing unit 22, a longitudinal cutting processing
unit, a transverse cutting processing unit, a longitudinal folding
processing unit, a transverse folding processing unit, a rounding
processing unit, an emboss processing unit, a printing unit, a
pseudo-adhering unit, a bonding unit, a binding unit, a perforating
unit and the like may be exemplified. Depending on the purpose of
processing the sheet 100, a necessary processing unit is
appropriately selected from these various processing units and a
selected processing unit is installed to any appropriate place in
the sheet processing unit 1. Further, the sheet processing unit 1
has a trash box for collecting cut chips which are generated upon
cutting of the sheet 100 at the bottom part thereof.
Electrical Configuration of Sheet Processing Device
[0023] FIG. 2 is a block diagram showing an electrical
configuration of the sheet processing device 1. The sheet
processing device 1 contains a control unit (central processing
unit (CPU)) 6 which controls various operations of the sheet
processing device 1. A variety of memories such as a read-only
memory (ROM), a random access memory (RAM) and electrically
erasable programmable read-only memory (EEPROM) are connected to
the control unit 6. An operation display panel 5 which contains
buttons, switches and a display is connected to the control unit 6.
A variety of motors such as a belt drive motor (belt drive unit)
41, a feeding table lift motor (lifting drive unit) 42, a main
motor 43, a first processing motor 44 and a second processing motor
45 are connected to the control unit 6. A variety of sensors such
as a sheet detection sensor 35, a first sheet position detection
sensor 36, a second sheet position detection sensor 37, a CCD
sensor 38 and a skew detection sensor 39 are connected to the
control unit 6.
[0024] The sheet 100 is fed by a belt 13 and a feeding position of
the sheet 100 on the feeding path 10 is determined by a rotation
amount of the belt drive motor 41 which moves the belt 13, that is,
a belt feeding amount of the belt 13.
[0025] The control unit 6 controls an entire operation of the sheet
processing device 1. At the same time, the control unit 6 controls
the feeding position of the sheet 100 (i.e., the rotation amount of
the belt drive motor 41) and various kinds of components in the
first processing unit 21 and the second processing unit 22. The
control unit 6 controls setting and registration of information on
a variety of processing jobs and notification of error information
through the operation display panel 5. The notification of
information means visual display on the display of the operation
display panel 5 and audio notification through a speaker. The
operation display panel 5 contains a start button. And pressing the
start button starts a sequence of sheet processing operations. A
CCD sensor 38 connected to the control unit 6 reads a barcode or
the like formed on the sheet 100 so as to automatically set and
register information on the variety of processing jobs.
Configuration of Feeding Device
[0026] The feeding device 7 contains a feeding table 30, a suction
feeding unit 8 and a separation blowing unit 31. A plurality of the
sheets 100 are stacked on the feeding table 30. A front stopper 15
is provided on a front side of the feeding table 30. Further, a
separation member 34 is provided at the top end of the front
stopper 15. Front ends of the sheets 100 abut against a front end
restriction surface 16 of the front stopper 15 to regulate a
position of the sheet 100. Consequently, the front ends of the
sheets 100 stacked on the feeding table 30 are positioned. The
feeding table 30 is electrically lifted up/down by a lift unit
which is driven by the feeding table lift motor 42. An upper limit
position and a lower limit position of the feeding table 30 are
detected by an upper limit sensor 32 and a lower limit sensor,
respectively. The upper limit sensor contains, for example, a
detection lever 32a and an optical sensor 32b. When a swinging
detection lever 32a blocks the optical sensor 32b, the control unit
6 detects that the feeding table 30 has reached a predetermined
height (the upper limit position). Further, as these sensors, for
example, a limit switch may be used and in this case, it functions
as a safety device for an emergency.
[0027] The feeding table 30 can be lifted up/down by a lifting
means (not shown). When supplying the sheet, the lifting means
ascends the feeding table 30 up to a predetermined height which
allows an uppermost sheet 100 to be sucked and fed by the suction
feeding unit 8. A fan 31 which blows air toward the front ends of
the sheets 100 on the feeding table 30 functions as a separation
blowing unit, so that the uppermost sheet 100 is separated from the
plurality of the stacked sheets 100. That is, the sheet 100 is
handled by air blown from the separation blowing unit 31. The
separated sheet 100 is sucked to the suction feeding unit 8 and fed
by the belt 13. The separation member 34 prevents a sheet 100
located below the uppermost sheet 100 sucked to the suction feeding
unit 8 from being fed in the downstream direction together with the
uppermost sheet 100. That is, the sheet 100 is separated more
accurately by the separation member 34.
[0028] The suction feeding unit 8 is provided over a front portion
of the feeding table 30. The suction feeding unit 8 includes the
belt 13, a pair of belt drive rollers 12, 12, a belt drive motor
41, a suction box (not shown), a suction fan 47 and a suction
detection sensor 33.
[0029] Depending on a kind, thickness and feeding speed of the
sheet 100, the suction feeding unit 8 can be arranged in an
inclined state at a predetermined inclination angle with respect to
the feeding direction F of the sheet 100 in a plan view. By
arranging the suction feeding unit 8 in the inclined state, the
sheet 100 can be fed in a state in which a side end of the sheet
100 is kept in contact with a side plate on one side provided on
the feeding device 7. The inclination angle is, for example,
0.degree. to 30.degree. and can be adjusted manually or
automatically. By arranging the suction feeding unit 8 in the
inclined state with the sheet 100 kept in contact with the side
plate on one side, the sheet 100 can be prevented from being fed in
a skewed state.
[0030] The belt 13 is formed in an endless shape and a plurality of
the belts 13 are disposed in line in a direction perpendicular to
the feeding direction F of the sheet 100. Each belt 13 is wound
around each of the pair of the belt drive rollers 12, 12 which are
spaced in the back and forth direction while arranged opposite to
each other. The sheet 100 is fed by the belt 13 while sucked to the
suction box. One of the pair of the belt drive rollers 12 is
connected to the belt drive motor 41 via a drive mechanism. When
the belt drive motor 41 is driven by the control unit 6, the one of
the belt drive rollers 12 rotates so that the belt 13 is circularly
traveled while the other of belt drive roller 12 is led to rotate.
That is, the control unit 6 controls the belt drive motor 41 so as
to move the belt 13 by driving the belt drive motor 41.
[0031] The belt drive motor 41 which moves the belt 13 serves as a
belt drive unit. The belt drive motor 41 is, for example, a
stepping motor, a servo motor or a DC motor. In case of the
stepping motor, the belt feeding amount of the belt 13 is
determined by a rotation amount proportional to the number of drive
pulses. In case of the servo motor, the belt feeding amount of the
belt 13 is determined by a rotation amount of an encoder
accompanying the servo motor. In case of the DC motor, the belt
feeding amount of the belt 13 is determined by a rotation amount of
an encoder arranged on an output shaft thereof.
[0032] The control unit 6 controls the belt drive motor 41 so as to
move the belt 13 in the feeding direction F or in a reverse feeding
direction B at a predetermined timing, by a predetermined feeding
amount or at a predetermined feeding speed. For example, the
control unit 6 controls the belt drive motor 41 so as to move the
belt 13 as a normal feeding in the feeding direction F by a
predetermined belt feeding amount at a first speed. Further, for
example, the control unit 6 controls the belt drive motor 41 so as
to move the belt 13 as a low-speed feeding in the feeding direction
F by a predetermined belt feeding amount at a second speed which is
lower than the first speed. Further, for example, the control unit
6 controls the belt drive motor 41 so as to move the belt 13 as a
reverse feeding by a predetermined belt reverse feeding amount at a
predetermined third speed.
[0033] The second speed mentioned here is lower than the first
speed, for example, approximately 25% of the first speed. The
predetermined belt feeding amount in the feeding direction F is a
feeding amount of the belt 13 which allows the sheet 100 to be fed
from a feeding start position at the feeding table 30 to at least
the sheet detection sensor 35. Preferably, the predetermined belt
feeding amount in the feeding direction F is, for example, a
feeding amount of the belt 13 equivalent to twice a distance R
between the sheet detection sensor 35 and the front end restriction
surface 16 of the front stopper 15 so that the sheet 100 can be fed
from the feeding start position up to the feeding roller 4 located
between the feeding device 7 and the first processing unit 21. The
predetermined belt reverse feeding amount in the reverse feeding
direction B is, for example, a reverse feeding amount of the belt
13 equivalent to a distance R between the sheet detection sensor 35
and the front end restriction surface 16 of the front stopper 15 so
that the sheet 100 which may be located in the upstream of the
sheet detection sensor 35 can be returned to the feeding table 30,
that is, the feeding start position. Here, the third speed upon the
reverse feeding of the belt 13, for example, lower than the first
speed so as to enhance a sheet feeding force upon the reverse
feeding.
[0034] When the suction fan 47 starts to operate, the internal
pressure in the suction box becomes negative. The suction detection
sensor 33 detects that the sheet 100 has been sucked to the suction
box. The suction detection sensor 33 contains, for example, a swing
member 33a and an optical sensor 33b. A lower end of the swing
member 33a protrudes downward from the lower surface of the suction
box. The optical sensor 33b contains a light emitting element and a
light receiving element. When the sheet 100 comes into contact with
the swing member 33a, the swing member 33a is pushed up so that it
swings. With a swing of the swing member 33a, an upper end of the
swing member 33a shields the optical sensor 33b so as to detect
that the sheet 100 has been sucked. When the optical sensor 33b
passes light, it can be detected that the sheet 100 has not been
sucked.
[0035] As shown in FIG. 1, a first sheet position detection sensor
36 is provided just in the downstream of the front stopper 15. The
first sheet position detection sensor 36 is a transmission type
photosensor in which a light emitting element and a light receiving
element are disposed to face each other with the feeding path 10
interposed therebetween. When the sheet 100 shields the first sheet
position detection sensor 36, it is detected that the sheet 100 has
passed.
[0036] In the downstream of the first sheet position detection
sensor 36, a sheet detection sensor 35 is provided between the
first processing unit 21 and the feeding roller 4 located in the
upstream of the first processing unit 21. The sheet detection
sensor 35 is a transmission type photosensor in which a light
emitting element and a light receiving element are disposed to face
each other with the feeding path 10 interposed therebetween. When a
front end of the sheet 100 shields the sheet detection sensor 35, a
position of the front end of the sheet 100, namely, an arrival of
the sheet 100 can be detected. The position of the front end of the
sheet 100 in the upstream of the sheet detection sensor 35 can be
calculated and estimated based on whether the sheet 100 is detected
by the first sheet position detection sensor 36 and based on a belt
feeding amount of the belt 13 from a position of the front end of
the sheet 100 when feeding starts (a drive amount or drive time of
the belt drive motor 41).
[0037] As shown in FIG. 3, the first sheet position detection
sensor 36 is located at a distance P in the downstream of the
feeding direction with respect to the front end restriction surface
16 of the front stopper 15. The distance P between the front end
restriction surface 16 and the first sheet position detection
sensor 36 in the feeding direction F corresponds to a reduced belt
reverse feeding amount P. The sheet detection sensor 35 is located
at a distance R in the downstream of the feeding direction with
respect to the front end restriction surface 16 of the front
stopper 15. The distance R between the front end restriction
surface 16 and the sheet detection sensor 35 in the feeding
direction F corresponds to a belt reverse feeding amount R. The
distance P, that is, the reduced belt reverse feeding amount P is
smaller than the distance R, that is, the belt reverse feeding
amount R.
Basic Operation of Sheet Processing Device
[0038] With reference to FIG. 1, a basic operation of the sheet
processing device 1 will be described below.
[0039] In the sheet processing device 1 of FIG. 1, information on
the variety of processing jobs (size and kind of the sheet 100,
arrangement, quantity, dimension and the like of object to be
processed) is set and registered using the operation display panel
5 (shown in FIG. 2). In the meantime, instead of this manual
setting and registration, the information on the variety of
processing jobs may be set and registered by reading a bar code
with a CCD sensor 38 (shown in FIG. 2) in cooperation with the
manual setting and registration.
[0040] In sequence to the above-mentioned setting and registration
operation, a following feeding operation is executed. When the
separation blowing unit 31 blows air toward the front ends of a
plurality of the sheets 100 stacked on the feeding table 30 of the
feeding device 7, the sheet 100 is separated from each other. Only
the uppermost sheet 100 is sucked to the suction feeding unit 8.
Suction of the sheet 100 is detected by the suction detection
sensor 33. When the suction detection sensor 33 detects that the
sheet 100 has been sucked, the control unit 6 controls the belt
driving motor 41 so as to move the belt 13. When the belt 13 is
moved, the sheet 100 is fed to the downstream side of the feeding
path 10 while sucked to a sheet feeding surface of the suction
feeding unit 8.
[0041] In sequence to the above-mentioned feeding operation, a
following processing operation is executed. The sheet 100 fed along
the feeding path 10 is held by the feeding rollers located between
the feeding device 7 and the first processing unit 21. The first
processing unit 21 and the second processing unit 22 may form a
plurality of slit lines, perforations or folds extending parallel
to the feeding direction F in the sheet 100 or perforations or
folds extending in a horizontal direction perpendicular to the
feeding direction F in the sheet 100.
[0042] In sequence to the above-mentioned processing operation, a
following discharge operation is executed. The processed object
subjected to various kinds of processing by the first processing
unit 21 and the second processing unit 22 is fed to the downstream
and collected in the discharge tray. On the other hand, margin
parts or shredded pieces are discharged to the trash box below.
Recovery Operation Upon Sheet Feeding
[0043] With reference to FIG. 6, a first recovery operation upon
sheet feeding according to a first embodiment will be described. It
should be noted that description overlapping with the
above-mentioned feeding operation will be omitted.
[0044] In FIG. 6, the feeding operation is started in step S1. In
step S3, the control unit 6 controls the belt driving motor 41 so
that the sheet 100 located at the feeding start position is sucked
by the suction feeding unit 8 so as to move the belt 13 in the
feeding direction F along the feeding path 10 by a predetermined
belt feeding amount in the feeding direction F along the feeding
path 10 at a predetermined first speed (to execute the first
operation as the normal feeding). In step S5, the control unit 6
determines whether the sheet detection sensor 35 is shielded by the
sheet 100 being fed. If the control unit 6 determines that the
sheet detection sensor 35 is shielded (YES in step S5), the control
unit 6 regards that the normal feeding has been executed and
completes the feeding operation (step S10).
[0045] If the control unit 6 determines that the sheet detection
sensor 35 is not shielded (NO in step S5), the control unit 6
controls the belt drive motor 41 so as to move the belt 13 in the
feeding direction F at the second speed which is lower than the
first speed by a predetermined belt feeding amount (to execute the
low-speed feeding) (step S7). Because the sheet 100 is slowly fed
at the second speed, a friction force between the belt 13 and the
sheet 100 is improved so as to improve the sheet feeding force of
the suction feeding unit 8. In the meantime, the predetermined belt
feeding amount upon the speed feeding is, for example, equal to the
predetermined belt feeding amount upon the normal feeding. In the
meantime, the predetermined belt feeding amount upon the low-speed
feeding may be different from the predetermined belt feeding amount
upon the normal feeding.
[0046] In step S9, the control unit 6 determines whether the sheet
detection sensor 35 is shielded by the sheet 100 being fed. If the
control unit 6 determines that the sheet detection sensor 35 is
shielded (YES in step S9), the control unit 6 regards that the
normal feeding has been executed and completes the feeding
operation (step S10).
[0047] If the control unit 6 determines that the sheet detection
sensor 35 is not shielded (NO in step S9), the control unit 6
increments a count number of the repetition number N by 1 (step
S11). In step S13, the control unit 6 determines whether the
repetition number N has reached a predetermined number A. The
predetermined number A is, for example, 3.
[0048] If the control unit 6 determines that the repetition number
N has not reached the predetermined number A (NO in step S13), the
control unit 6 controls the belt drive motor 41 so as to move the
belt 13 in the reverse feeding direction B which is opposite to the
feeding direction F by the predetermined belt reverse feeding
amount (to feed the belt 13 reversely) (step S15). In this way, the
control unit 6 controls the belt drive motor 41 so as to execute
the normal feeding (the first operation) in step S3 and a first
recovery operation from step S7 to the reverse feeding in step S15.
In the meantime, the predetermined belt reverse feeding amount is a
belt reverse feeding amount which allows a sheet 100 which may not
have reached the sheet detection sensor 35 to return to the feeding
table 30 (that is, to return to an original feeding start
position). The predetermined belt reverse feeding amount is a
reverse feeding amount equivalent to, for example, the distance R
between the sheet detection sensor 35 and the front end restriction
surface 16 of the front stopper 15. If the low-speed feeding of the
sheet 100 fails, the feeding operation can be executed again by
returning the sheet 100 to the original feeding start position by
the reverse feeding. There is a high possibility that the feeding
may be finally completed by executing the feeding operation
again.
[0049] After the first recovery operation from the low-speed
feeding at the second speed in step S7 up to the reverse feeding in
step S15 is executed, the control unit 6 controls the belt drive
motor 41 so as to execute the normal feeding (the first operation)
in step S3 again. Then, the above-mentioned step S5, step S7, step
S9, step S11, step S13 and step S15 are executed in sequence. If
the control unit 6 determines that the repetition number N has
reached the predetermined number A (YES in step S13), the control
unit 6 regards that an abnormal feeding has been executed and then
terminates the feeding operation (step S17). Then, the control unit
6 controls the operation display panel 5 so as to display or notify
its feeding error.
[0050] If in the first operation, the sheet 100 has not been fed up
to the position of the sheet detection sensor 35 due to an idle
feeding of the sheet 100, the sheet feeding force is enhanced by
adopting the lower second speed. However, if the sheet 100 still
cannot be fed although the sheet feeding force is enhanced, the
first recovery operation in which the sheet is reversely fed to the
feeding table 30 or the original feeding start position is
executed. Even if any abnormal state occurs in the feeding
operation, the abnormal state can be easily recovered to the normal
state by returning the sheet 100 to the original feeding start
position.
[0051] After the first recovery operation from the low-speed
feeding at the second speed in step S7 to the reverse feeding in
step S15 is executed, the control unit 6 can control the belt drive
motor 41 so as to repeat the first recovery operation by repeating
the first recovery operation from the low-speed feeding at the
second speed in step S7 up to the reverse feeding in step S15.
Reverse Feeding in First Recovery Operation
[0052] With reference to FIG. 3 and FIG. 7, the reverse feeding in
the first recovery operation according to a second embodiment will
be described. The reverse feeding according to the second
embodiment corresponds to the reverse feeding in step S15 in FIG.
6.
[0053] In FIG. 7, the reverse feeding is started in step S21. In
step S22, the control unit 6 determines whether the first sheet
position detection sensor 36 is shielded by the sheet 100 being
reversely fed.
[0054] If the control unit 6 determines that the first sheet
position detection sensor 36 is shielded (NO in step S22), the
control unit 6 regards that the front end of the sheet 100 is
located in the upstream of the first sheet position detection
sensor 36 and controls the belt drive motor 41 so as to move the
belt 13 in the reverse feeding direction B at a third speed by the
reduced belt reverse feeding amount P (to feed the belt 13
reversely). Then, the control unit 6 regards that the reverse
feeding is terminated by moving the belt 13 in the reverse feeding
direction B by the reduced belt reverse feeding amount P (step
S25).
[0055] If in step S22, the control unit 6 determines that the first
sheet position detection sensor 36 is shielded (YES in step S22),
the control unit 6 regards that the front end of the sheet 100 is
located in the downstream of the first sheet position detection
sensor 36 and controls the belt drive motor 41 so as to move the
belt 13 at the third speed, by the belt reverse feeding amount R in
the reverse feeding direction B (to feed the belt 13 reversely)
(step S24). Then, the control unit 6 regards that the reverse
feeding is terminated by moving the belt 13 in the reverse feeding
direction B by the belt reverse feeding amount R (step S25).
[0056] When executing the reverse feeding, a distance necessary for
the reverse feeding can be reduced by detecting a position of the
front end of the sheet 100 with the first sheet position detection
sensor 36, thereby shortening a time required for the reverse
feeding.
[0057] With reference to FIG. 4 and FIG. 8, a reverse feeding in
the first recovery operation according to a third embodiment will
be described. The reverse feeding in the first recovery operation
according to the third embodiment corresponds to the reverse
feeding in step S15 in FIG. 6.
[0058] As shown in FIG. 4, a second sheet position detection sensor
37 is provided between the first sheet position detection sensor 36
and the sheet detection sensor 35. The second sheet position
detection sensor 37 is a transmission type photosensor in which a
light emitting element and a light receiving element are disposed
to face each other with the feeding path 10 interposed
therebetween. When the sheet 100 shields the first sheet position
detection sensor 36, it is detected that the sheet 100 has passed.
The second sheet position detection sensor 37 is located at a
distance Q in the downstream of the feeding direction with respect
to the front end restriction surface 16 of the front stopper 15.
The distance Q between the front end restriction surface 16 and the
second sheet position detection sensor 37 in the feeding direction
F corresponds to a reduced belt reverse feeding amount Q. The
distance Q, that is, the reduced belt reverse feeding amount Q is
smaller than the belt reverse feeding amount R and larger than the
reduced belt reverse feeding amount P.
[0059] In FIG. 8, the reverse feeding is started in step S31. In
step S32, the control unit 6 determines whether the first sheet
position detection sensor 36 is shielded by the sheet 100 being
reversely fed. If the control unit 6 determines that the first
sheet position detection sensor 36 is not shielded (NO in step
S32), the control unit 6 regards that the front end of the sheet
100 is located in the upstream of the first sheet position
detection sensor 36 and controls the belt drive motor 41 so as to
move the belt 13 in the reverse feeding direction B at the third
speed by the reduced belt reverse feeding amount P (to feed the
belt 13 reversely) (step S33). Then, the control unit 6 regards
that the reverse feeding is terminated by moving the belt 13 in the
reverse feeding direction B by the reduced belt reverse feeding
amount P (step S37).
[0060] In step S32, if the control unit 6 determines that the first
sheet position detection sensor 36 is shielded (YES in step S32),
the control unit 6 proceeds to step S34 where the control unit 6
determines whether the second sheet position sensor 37 is shielded
by the sheet 100 being reversely fed (step S34).
[0061] If the control unit 6 determines that the second sheet
position detection sensor 37 is not shielded (NO in step S34), the
control unit 6 regards that the front end of the sheet 100 is
located in the downstream of the first sheet position detection
sensor 36 and further in the upstream of the second sheet position
detection sensor 37. Then, the control unit 6 controls the belt
drive motor 41 so as to move the belt 13 at the third speed, by the
reduced belt reverse feeding amount Q in the reverse feeding
direction B (to feed the belt 13 reversely) (step S35). Then, the
control unit 6 regards that the reverse feeding is terminated by
moving the belt 13 in the reverse feeding direction B by the
reduced belt reverse feeding amount Q (step S37).
[0062] In step S34, if the control unit 6 determines that the
second sheet position detection sensor 37 is shielded (YES in step
S34), the control unit 6 regards that the front end of the sheet
100 is located in the downstream of the second sheet position
detection sensor 37. Then, the control unit 6 controls the belt
drive motor 41 so as to move the belt 13 at the third speed, by the
belt reverse feeding amount R in the reverse feeding direction B
(to feed the belt 13 reversely) (step S36). Then, the control unit
6 regards that the reverse feeding is terminated by moving the belt
13 in the reverse feeding direction B by the belt reverse feeding
amount R (step S37).
[0063] When executing the reverse feeding, a distance necessary for
the reverse feeding can be further reduced by finely detecting a
position of the front end of the sheet 100 with the second sheet
position detection sensor 37 as well as the first sheet position
detection sensor 36, thereby further shortening a time required for
the reverse feeding.
[0064] With reference to FIG. 9, a reverse feeding in the first
recovery operation according to a fourth embodiment will be
described.
[0065] In FIG. 9, the reverse feeding is started in step S41. In
step S42, the control unit 6 determines whether the first sheet
position detection sensor 36 is shielded by the sheet 100 being
reversely fed. If the control unit 6 determines that the first
sheet position detection sensor 36 is not shielded (NO in step
S42), the control unit 6 regards that the front end of the sheet
100 is located in the upstream of the first sheet position
detection sensor 36. Then, the control unit 6 controls the belt
drive motor 41 so as to move the belt 13 in the reverse feeding
direction B at the third speed by the reduced belt reverse feeding
amount P (to feed the belt 13 reversely) (step S43).
[0066] In step S42, if the control unit 6 determines that the first
sheet position detection sensor 36 is shielded (YES in step S42),
the control unit 6 proceeds to step S44 where the control unit 6
determines whether the second sheet position sensor 37 is shielded
by the sheet 100 being reversely fed (step S44).
[0067] If the control unit 6 determines that the second sheet
position detection sensor 37 is not shielded (NO in step S44), the
control unit 6 regards that the front end of the sheet 100 is
located in the downstream of the first sheet position detection
sensor 36 and further in the upstream of the second sheet position
detection sensor 37. Then, the control unit 6 controls the belt
drive motor 41 so as to move the belt 13 at the third speed, by the
reduced belt reverse feeding amount Q in the reverse feeding
direction B (to feed the belt 13 reversely) (step S45).
[0068] In step S44, if the control unit 6 determines that the
second sheet position detection sensor 37 is shielded (YES in step
S44), the control unit 6 regards that the front end of the sheet
100 is located in the downstream of the second sheet position
detection sensor 37. Then, the control unit 6 controls the belt
drive motor 41 so as to move the belt 13 at the third speed, by the
belt reverse feeding amount R in the reverse feeding direction B
(to feed the belt 13 reversely) (step S46). In the meantime, the
reduced belt reverse feeding amount Q is smaller than the belt
reverse feeding amount R and larger than the reduced belt reverse
feeding amount P.
[0069] In step S47, the control unit 6 reversely feeds the sheet
100 by moving the belt 13 by the reduced belt reverse feeding
amount P, the reduced belt reverse feeding amount Q or the belt
reverse feeding amount R in the reverse feeding direction B, and
then, the control unit 6 determines whether the first sheet
position detection sensor 36 passes light.
[0070] If the control unit 6 determines that the first sheet
position detection sensor 36 is not shielded (NO in step S47), the
control unit 6 regards that the front end of the sheet 100 is
located in the downstream of the first sheet position detection
sensor 36 (that is, the sheet has not returned to the original
feeding start position) and terminates as the reverse feeding due
to an error (step S49).
[0071] In step S47, if the control unit 6 determines that the first
sheet position detection sensor 36 passes light (YES in step S47),
the control unit 6 regards that the front end of the sheet 100 is
located in the upstream of the first sheet position detection
sensor 36 (that is, the sheet has returned to the original feeding
start position) and completes the reverse feeding (step S48).
[0072] After feeding the sheet 100 reversely by moving the belt 13
by the reduced belt reverse feeding amount P, the reduced belt
reverse amount Q or the belt reverse feeding amount R, presence or
absence of the sheet 100 is detected with the first sheet position
detection sensor 36 nearest the feeding table 30. Consequently, it
can be easily determined whether the sheet 100 has returned to the
original feeding start position.
[0073] In the meantime, in case of NO in step S42, the first sheet
position detection sensor 36 passes light even before feeding the
sheet 100 reversely. Thus, after feeding the sheet 100 reversely by
the reduced belt reverse feeding amount P in step S43, it is
permissible to directly proceed to step S48 without determining
whether the first sheet position detection sensor 36 passes light
and then complete the reverse feeding.
[0074] Next, with reference to FIG. 10, a second recovery operation
upon sheet feeding according to a fifth embodiment will be
described. It should be noted that description overlapping with the
above-mentioned first recovery operation will be omitted.
[0075] The second recovery operation according to the fifth
embodiment is characterized by executing the following. That is,
the feeding operation is started in step S51 compared with the
first recovery operation. Then, the normal feeding at the first
speed (first operation) is executed (step S52), and when an arrival
of the sheet 100 cannot be detected (NO in step S53), the reverse
feeding is executed (step S56). After that, the low-speed feeding
at the second speed is executed (step S57).
[0076] That is, when the first operation is executed and an arrival
of the sheet 100 cannot be detected by the sheet detection sensor
35, the control unit 6 controls the belt drive motor 41 so as to
execute the second recovery operation of moving the belt 13 in the
reverse feeding direction B by the belt reverse amount R which is
capable of feeding the sheet 100 in the reverse feeding direction B
opposite to the feeding direction F to the feeding table 30 and
further moving the belt 13 at the second speed lower than the first
speed by the belt feeding amount R. In the meantime, if the control
unit 6 determines that the sheet detection sensor 35 is shielded
(YES in step S53), the control unit 6 regards that the normal
feeding is executed and then completes the feeding operation (step
S58).
[0077] Unless the sheet 100 has been fed to the sheet detection
sensor 35 due to the idle feeding or the like in this way, the
sheet 100 is reversely fed to the feeding table 30 or the original
feeding start position. Then, the sheet 100 is fed from the
original feeding start position at the lower second speed in the
feeding direction F, thereby enhancing the sheet feeding force.
Consequently, the abnormal state upon feeding of the sheet 100 is
recovered to the normal state thereby increasing a possibility that
the feeding of the sheet 100 may be finally completed.
[0078] In the meantime, in the second recovery operation according
to the fifth embodiment, unless an arrival of the sheet 100 can be
detected even if the sheet 100 is fed at the lower second speed,
the sheet 100 may be reversely fed and returned to the feeding
table 30 or the original feeding start position.
[0079] In the second recovery operation according to the fifth
embodiment, the control unit 6 can control the belt drive motor 41
so as to repeat the second recovery operation. That is, steps (step
S54 and step S55) of determining the repetition number N may be
provided between the step (step S53) of determining whether the
sheet detection sensor 35 is shielded and the step (step S56) of
the reverse feeding. In this case, if the control unit 6 determines
that the sheet detection sensor 35 is not shielded (NO in step
S53), the control unit 6 increments the count number of the
repetition number N by 1 (step S54). In step S55, the control unit
6 determines whether the repetition number N has reached a
predetermined number A. The predetermined number A is, for example,
3. If the control unit 6 determines that the repetition number N
has not reached the predetermined number A (NO in step S55), the
control unit 6 controls the belt drive motor 41 so as to feed the
sheet 100 reversely (step S56) and after that, move the belt 13
slowly at the second speed (step S57). If the control unit 6
determines that the repetition number N has reached the
predetermined number A (YES in step S55), the control unit 6
regards that the abnormal feeding is executed and terminates the
feeding operation (step S59).
[0080] Like the first recovery operation according to the second
embodiment (shown in FIG. 7), it is permissible to detect the front
end of the sheet 100 with the first sheet position detection sensor
36 upon the reverse feeding. This configuration can reduce a
distance necessary for the reverse feeding.
[0081] Like the first recovery operation according to the third
embodiment (shown in FIG. 8), it is permissible to detect the front
end of the sheet 100 more finely with the second sheet position
detection sensor 37 as well as the first sheet position detection
sensor 36 upon the reverse feeding. This configuration can reduce a
distance necessary for the reverse feeding thereby further
shortening a time required for the reverse feeding.
[0082] Further, like the first recovery operation according to the
fourth embodiment (shown in FIG. 9), it is permissible to move the
belt 13 by the reduced belt reverse feeding amount P, the reduced
belt reverse feeding amount Q or the belt reverse amount R to feed
the sheet 100 reversely and after that, detect presence or absence
of the sheet 100 with the first sheet position detection sensor 36
nearest the feeding table 30. This configuration can easily
determine whether the sheet 100 has returned to the original
feeding start position.
[0083] The control unit 6 can change the second speed upon the
low-speed feeding depending on the size and/or basis weight of the
sheets 100. For example, when feeding a thin sheet 100 at a low
speed, it can be stably fed at the low speed by lowering the second
speed compared to a case of feeding a thick sheet 100. That is, the
control unit 6 controls the belt drive motor 41 so that the more
flexible the sheet 100, the lower the second speed upon the
low-speed feeding depending on the size and/or basis weight of the
sheet 100.
[0084] The control unit 6 can change the third speed upon the
reverse feeding depending on the size and/or basis weight of the
sheets 100. For example, when feeding the thin sheet 100 reversely,
the thin sheet can be reversely fed stably by lowering the third
speed compared to the thick sheet 100. That is, the control unit 6
controls the belt drive motor 41 so that the more flexible the
sheet 100, the lower the third speed upon the reverse feeding
depending on the size and/or basis weight of the sheet 100.
[0085] The control unit 6 can control the belt drive motor (belt
drive unit) 41 so as to increase the predetermined belt feeding
amount as the repetition number of the first recovery operation or
the second recovery operation increases. The repetition number of
the first recovery operation or the second recovery operation
mentioned here means a repetition number of repeating the first
operation, the low-speed feeding and then the reverse feeding or a
repletion number of repeating the low-speed feeding and then the
reverse feeding or a repetition number of repeating the reverse
feeding and then the low-speed feeding. According to this control,
in case where an arrival of the sheet 100 can be detected with the
sheet detection sensor 35 only by increasing the predetermined belt
feeding amount a little more, the sheet 100 can be detected with
the sheet detection sensor 35 only by feeding the belt 13 a little
more. Thus, the reverse feeding becomes unnecessary, thereby a time
required for the feeding operation can be shortened. Particularly,
this control is effective for a slippery sheet 100.
[0086] The control unit 6 can control the feeding table lift motor
(lift driving unit) 42 so as to descend the feeding table 30 when
moving the belt 13 in the reverse feeding direction B. According to
this control, especially when a thick sheet 100 is reversely fed
and returned to the feeding table 30 (that is, the original feeding
start position), a rear end of the sheet 100 can be prevented from
making contact with the upper limit sensor 32.
[0087] The control unit 6 can control the feeding table lift motor
(lift driving unit) 42 so as to move the belt 13 in the reverse
feeding direction B after the feeding table 30 starts to descend.
For example, the control unit 6 can control the feeding table lift
motor (lift driving unit) 42 so as to move the belt 13 in the
reverse feeding direction B after the feeding table 30 has been
lowered to a position where the rear end of the sheet 100 can avoid
contact with the upper limit sensor 32. According to this control,
contact of the rear end of the sheet 100 with the upper limit
sensor 32 can be surely avoided.
[0088] Depending on the size of the sheet 100, the control unit 6
can control the feeding table lift motor (lift driving unit) 42
about whether or not the feeding table 30 will descend when
executing the reverse feeding. If the sheet 100 is an elongated
object which is longer than a predetermined length in the feeding
direction F, the rear end of the sheet 100 is located in the
downstream of the upper limit sensor 32, before the front end of
the sheet 100 fed in the feeding direction F reaches a position
detected by the sheet detection sensor 35. Thus, according to this
control, an operating of descending the feeding table 30 can be
omitted, thereby shortening a time required for the reverse
feeding. The presence or absence of descent control of the feeding
table 30 can be executed by user's arbitrary setting or by
detecting the size of the sheet 100.
[0089] The control unit 6 can control the separation blowing unit
31 so as to adjust air flow rate of the separation blowing unit 31
depending on a position of the front end of the sheet 100 being
fed. Specifically, the control unit 6 controls the separation
blowing unit 31 so as to decrease the air flow rate or turn off air
blowing in a period until the front end of the sheet 100 reaches
the position of the sheet detection sensor 35 after a suction of
the sheet 100 is detected by the suction detection sensor 33.
According to this control, a sheet 100 following the uppermost
sheet 100 is prevented from flying up unnecessarily, thereby
preventing double feeding and chain feeding of the sheets. That is,
when feeding the sheet 100, the double feeding or the chain feeding
can be prevented more easily by stopping the separation of the
sheet 100 temporarily.
[0090] Further, as shown in FIG. 5, the feeding device 7 includes
the suction feeding unit 8 having the belt 13 for feeding the sheet
100 along the feeding path 10 by sucking the sheet 100 on the
feeding table 30 and the belt drive motor (belt drive unit) 41 for
moving the belt 13, the skew detection sensor 39 which is provided
in the feeding path 10 in the downstream of the suction feeding
unit 8 in order to detect the presence or absence of a skew feeding
of the sheet 100 and the control unit 6 for controlling the belt
drive motor (belt drive unit) 41.
[0091] The skew detection sensor 39 is a transmission type
photosensor containing a pair of a light emitting element and a
light receiving element disposed to face each other with the
feeding path 10 interposed therebetween. The skew detection sensor
39 has two pairs of the transmission type photosensors which are
spaced in a direction perpendicular to the feeding path 10. The
skew detection sensors 39 are arranged substantially at the same
positions as the sheet detection sensors 35 in the feeding path 10.
Thus, the skew detection sensors 39 can also serve as the sheet
detection sensors 35. If the skew detection sensors 39 are shielded
by the front end of the sheet 100 substantially at the same time,
the control unit 6 determines that the skew feeding of the sheet
100 does not occur. If the skew detection sensors are shielded by
the front end of the sheet 100 with a certain time difference, the
control unit 6 determines that the skew feeding occurs.
[0092] If the skew feeding of the sheet 100 is detected by the skew
detection sensor 39, the control unit 6 controls the belt drive
motor (belt drive unit) 41 so as to move the belt 13 in the reverse
feeding direction B opposite to the feeding direction F by a
predetermined belt reverse feeding amount. According to this
control, when the skew feeding of the sheet 100 is detected, the
sheet 100 can be returned to the feeding table 30 (that is, the
original feeding start position), because the skew feeding is one
of abnormal states upon the feeding of the sheet 100.
[0093] When the sheet 100 returns to the feeding table 30 (that is,
returns to the original feeding start position), the control unit 6
controls the belt drive motor (belt drive unit) 41 so as to execute
the normal feeding. However, if the skew feeding of the sheet 100
is detected again, the control unit 6 controls the belt drive motor
(belt drive unit) 41 so as to repeat the reverse feeding. According
to this control, the feeding operation can be executed again. By
executing the feeding operation again, a possibility that the
feeding operation is finally completed becomes high.
[0094] If a suction of the sheet 100 is detected by the suction
detection sensor 33, the control unit 6 can control the feeding
table lift motor (lift driving unit) 42 so as to repeat slight
ascending and descending of the feeding table (for example, about 5
mm). According to this control, since it is easy for air blowing
from the separation blowing unit 31 to reach the sheet 100, the
separation action of the sheet 100 can be promoted.
[0095] When repeating the first recovery operation or the second
recovery operation, the control unit 6 can control the belt drive
motor 41 so as to lengthen a feeding start time until the feeding
of the sheet 100 starts after the suction of the sheet 100 is
detected. According to this control, when a next sheet 100 is
adhered to a sucked sheet 100, a postponement time for detachment
of an adhered sheet 100 is provided, so that the separation action
of the sheet 100 can be promoted.
[0096] In the first recovery operation and the second recovery
operation, the control unit 6 can control the recovery operation so
as to be executed only once by setting the predetermined number A
to 2 in order to recover to the normal state. However, by setting
the predetermined number A to 3 or more and controlling so as to
repeat the recovery operation multiple times, a possibility of the
recovery to the normal state can be further enhanced.
[0097] As described above, the feeding device 7 according to the
present disclosure has following excellent effects.
[0098] (1) A feeding device 7 comprises a suction feeding unit 8
having a belt 13 for feeding a sheet 100 on a feeding table 30
along a feeding path 10 in a suction state, and a belt drive unit
41 for moving said belt 13; a sheet detection sensor 35 that is
provided in said feeding path 10 in a downstream of said suction
feeding unit 8 and detects presence or absence of the sheet 100;
and a control unit 6 for controlling said belt drive unit 41. The
control unit 6 controls said belt drive unit 41 so as to execute a
first operation of moving said belt 13 in a feeding direction F at
a first speed by a belt feeding amount capable of feeding said
sheet 100 from said feeding table 30 to said sheet detection sensor
35. If the first operation is executed and an arrival of said sheet
100 cannot be detected by said sheet detection sensor 35, said
control unit 6 controls said belt drive unit 41 so as to execute a
low-speed feeding of moving said belt 13 in the feeding direction F
at a second speed lower than the first speed by the belt feeding
amount or so as to execute a reverse feeding of moving said belt 13
in a reverse feeding direction B opposite to the feeding direction
F by a belt reverse feeding amount capable of feeding said sheet
100 up to said feeding table 30. Thereby, if any abnormal state
occurs upon feeding of the sheet 100, the abnormal state in the
feeding can be recovered to a normal state by feeding the sheet 100
with a sheet feeding force enhanced by the low-speed feeding or by
returning the sheet 100 by the reverse feeding finally to the
original feeding start position.
[0099] (2) The control unit 6, if the low-speed feeding is executed
and an arrival of said sheet 100 cannot be detected by said sheet
detection sensor 35, controls said belt drive unit 41 so as to
execute the reverse feeding. Thereby, even if any abnormal state
occurs upon feeding of the sheet 100, the abnormal state can be
easily recovered to the normal state by returning the sheet 100 to
the feeding table 30 (that is, the original feeding start position)
finally.
[0100] (3) The control unit 6 controls said belt drive unit 41 so
as to repeat the low-speed feeding after executing said first
operation and then further said reverse feeding or so as to repeat
said reverse feeding after executing said low-speed feeding.
Thereby, the feeding operation can be continued.
[0101] (4) The control unit 6 controls said belt drive unit to
execute said low-speed feeding after said reverse feeding. Thereby,
the sheet feeding force is enhanced so that there is a high
possibility that the feeding is finally completed by returning from
the abnormal state in the feeding to the normal state.
[0102] (5) The control unit 6 controls said belt drive unit so as
to repeat executing said low-speed feeding after executing said
reverse feeding. Thereby, the feeding operation can be
continued.
[0103] (6) The feeding device 7 further comprises sheet position
detection sensors 36, 37 that are provided in the upstream of said
sheet detection sensor 35 in said feeding path and detects a
position of a front end of said sheet 100, wherein said control
unit 6 controls said belt drive unit 41 so as to reduce said belt
reverse feeding amount depending on the position of said sheet 100
detected by said sheet position detection sensors 36, 37 and move
said belt 13 in the reverse feeding direction B. Thereby, since the
sheet feeding force is enhanced by feeding the sheet 100 in the
reverse direction and then feeding the sheet 100 from the original
feeding start position in the feeding direction F at the low second
speed, there is a high possibility that the feeding is finally
completed by returning from the abnormal state in the feeding to
the normal state.
[0104] (7) The control unit 6 controls said belt drive unit 41 so
as to move said belt 13 in a reverse feeding direction B at a third
speed lower than said first speed. Thereby, the sheet feeding force
upon the reverse feeding can be enhanced.
[0105] (8) The control unit 6 changes said second speed depending
on a size and/or basis weight of said sheet 100. Thereby, the sheet
can be stably fed upon the low-speed feeding.
[0106] (9) The control unit 6 changes the third speed depending on
the size and/or basis weight of the sheet. Thereby, the sheet 100
can be stably fed upon the reverse feeding.
[0107] (10) The control unit 6 controls said belt drive unit so as
to increase said belt feeding amount as said repetition number
increases. Thereby, the reverse feeding becomes unnecessary,
thereby shortening a time required for the feeding operation.
[0108] (11) The feeding device further comprises a lift driving
unit 42, wherein said feeding table 30can be lifted up/down by said
lift driving unit 42 and said control unit 6, when moving said belt
13 in the reverse feeding direction B, controls said lift driving
unit 42 so as to descend said feeding table 30. Thereby, the rear
end of the sheet 100 can be prevented from coming into contact with
the upper limit sensor 32.
[0109] (12) A feeding device comprises a suction feeding unit 8
having a belt 13 for feeding a sheet 100 on a feeding table 30
along a feeding path 10 in a suction state, and a belt drive unit
41 for moving said belt 13; a skew detection sensor 39 that is
provided in said feeding path 10 in a downstream of said suction
feeding unit 8 and detects presence or absence of a skewed state of
said sheet 100; and a control unit 6 for controlling said belt
drive unit 4l. The control unit 6 controls said belt drive unit 41
so as to execute a first operation of moving said belt 13 in a
feeding direction F at a first speed by a belt feeding amount
capable of feeding said sheet from said feeding table 30 to said
skew detection sensor 39. The control unit 6, if the skewed state
of said sheet 100 is detected by said skew detection sensor 39,
controls said belt drive unit 41 so as to execute a reverse feeding
of moving said belt 13 in a reverse feeding direction B opposite to
the feeding direction F by a belt reverse feeding amount capable of
feeding said sheet 13 detected as being in the skewed state up to
said feeding table 30. Thereby, the feeding operation can be
executed again, and by executing the feeding operation again, there
is a high possibility that the feeding is finally completed.
[0110] (13) The control unit 6 controls said belt drive unit 41 so
as to repeat said first operation after executing said reverse
feeding or so as to repeat a second operation of moving said belt
13 in the feeding direction F at a second speed lower than said
first speed after executing said reverse feeding. Thereby, the
feeding operation can be executed again, and by executing the
feeding operation again, there is a high possibility that the
feeding is finally completed.
[0111] (14) A sheet processing device 1 comprises a feeding device
7 described above and a sheet processing unit 21 for executing a
predetermined processing on a sheet 100 supplied by said feeding
device 7. Thereby, even if any abnormal state occurs upon feeding
of the sheet 100, the abnormal state can be easily recovered by
enhancing the sheet feeding force or by returning the sheet to the
original feeding start position.
[0112] Although specific embodiments of the present invention have
been described above, the present invention is not restricted to
the above-described embodiments but may be modified and executed in
various ways within the scope of the present invention. Further, an
embodiment in which contents described in the above embodiments are
suitably combined may be one embodiment of the present
invention.
[0113] Although the control unit 6 controls the belt drive motor 41
so as to move the belt 13 at the third speed as the reverse feeding
speed, the control unit 6 may control the belt drive motor 41 so as
to move the belt 13 in the reverse feeding direction B at the first
speed as the reverse feeding speed.
[0114] Since the sheet detection sensor 35 is provided between the
feeding roller 4 located in the upstream of the first processing
unit 21 and the first processing unit 21, the detection by the
sheet detection sensor 35 is executed in a state in which the sheet
100 is nipped by the feeding roller 4 having a higher sheet feeding
force than the suction feeding unit 8. By the way, when the sheet
100 needs to be processed at a predetermined processing timing in
the processing by the first processing unit 21, the processing
timing is adjusted based on a position of the front end of the
sheet 100 detected by the sheet detection sensor 35. That is, since
the sheet 100 detected by the sheet detection sensor 35 is fed
toward the first processing unit 21 by the feeding roller 4 having
a high sheet feeding force, it is possible to process at the
predetermined processing timing in accordance with a processing
position of the sheet 100, and to suppress occurrence of a
deviation of the processing position.
[0115] Although if NO in step S47, the control unit 6 controls so
as to terminate as the reverse feeding due to the error, the
control unit 6 may control as follows. If the control unit 6
determines that the first sheet position detection sensor 36 is not
shielded (NO in step S47), the control unit 6 regards that the
front end of the sheet 100 is located in the downstream of the
first sheet position detection sensor 36 (that is, the sheet 100
has not returned to the original feeding start position) and
terminates as the reverse feeding due to the error (step S49). That
is, when the control unit 6 determines that the first sheet
position detection sensor 36 passes no light, the control unit 6
may control so as to repeat the reverse feeding, for example, up to
three times and if the first sheet position detection sensor 36
passes no light despite three reverse feedings, the control unit 6
may control so as to terminate as the reverse feeding due to the
error.
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