U.S. patent application number 11/099448 was filed with the patent office on 2005-10-20 for sheet treating apparatus and image forming apparatus therewith.
This patent application is currently assigned to CANON FINETECH INC.. Invention is credited to Funada, Naoyasu.
Application Number | 20050230896 11/099448 |
Document ID | / |
Family ID | 35095485 |
Filed Date | 2005-10-20 |
United States Patent
Application |
20050230896 |
Kind Code |
A1 |
Funada, Naoyasu |
October 20, 2005 |
Sheet treating apparatus and image forming apparatus therewith
Abstract
An object of the invention is to provide a sheet treating
apparatus and an image forming apparatus therewith which can
securely perform stapling treatment even to a sheet stack, in which
the sheets having different sizes are mixed, and improve appearance
of the sheet stack when the stapling treatment is performed to the
sheet stack. In order to achieve the object, in a sheet treating
apparatus having sheet stacking unit for stacking a sheet to be
treated, the apparatus forming a sheet stack by aligning the sheets
conveyed to the sheet stacking unit and performing binding
treatment to the aligned sheet stack by binding unit, the sheet
treating apparatus includes a side-end regulation member which is
provided on a side of a width direction orthogonal to a sheet
conveying direction of the sheet stacking unit, the side-end
regulation member regulating an end-portion position in the width
direction of the sheet; and moving unit for moving the sheet in the
width direction to cause the sheet to abut on the side-end
regulation member.
Inventors: |
Funada, Naoyasu;
(Moriya-shi, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON FINETECH INC.
MITSUKAIDO-SHI
JP
|
Family ID: |
35095485 |
Appl. No.: |
11/099448 |
Filed: |
April 6, 2005 |
Current U.S.
Class: |
270/58.08 |
Current CPC
Class: |
B65H 2404/1521 20130101;
B65H 2801/27 20130101; B65H 31/26 20130101; B65H 2404/1523
20130101; B65H 31/34 20130101; B65H 2301/3621 20130101 |
Class at
Publication: |
270/058.08 |
International
Class: |
B65H 033/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 16, 2004 |
JP |
2004-122290 |
Claims
What is claimed is:
1. A sheet treating apparatus having sheet stacking means for
stacking a sheet to be treated, said apparatus forming a sheet
stack by aligning the sheets conveyed to said sheet stacking means
and performing binding treatment to the aligned sheet stack by
binding means, said apparatus comprising: a side-end regulation
member which is provided on a side of a width direction orthogonal
to a sheet conveying direction of said sheet stacking means, said
side-end regulation member regulating an end-portion position in
the width direction of the sheet; and moving means for moving the
sheet in the width direction to cause the sheet to abut on said
side-end regulation member, wherein said moving means moves the
sheet in the width direction to cause the sheet to abut on said
side-end regulation member in each time when the sheet is conveyed
to said sheet stacking means such that the end portions in the
width directions of the sheets whose lengths differ from one
another in the width direction are aligned.
2. The sheet treating apparatus according to claim 1, wherein said
moving means moves the sheet in the width direction by a distance
corresponding to the length in the width direction.
3. The sheet treating apparatus according to claims 1 or 2, further
comprising holding means for holding the sheet abutting on said
side-end regulation member, wherein said moving means moves the
sheet in the width direction to cause the sheet to abut on said
side-end regulation member in each time when the sheet is conveyed
to said sheet stacking means, in a state that the sheet abutting on
said side-end regulation member is held by said holding means.
4. The sheet treating apparatus according to claim 1 or 2, said
moving means separates the sheet having a predetermined length in
the width direction from said side-end regulation member by a
predetermined distance in the width direction, after said moving
means causes the sheet to abut on said side-end regulation
member.
5. The sheet treating apparatus according to claim 4, wherein said
binding means is configured to be movable in the width direction to
a predetermined position where the sheets are bound, the
predetermined position being separated from said side-end
regulation member by a predetermined distance.
6. The sheet treating apparatus according to claims 1 or 2, wherein
said moving means includes: sheet conveying means for conveying the
conveyed sheet in the opposite direction to the sheet conveying
direction, said sheet conveying means being provided in a side-end
portion on the upstream side in the sheet conveying direction of
said sheet stacking means, said sheet conveying means causing the
sheet to abut on said side-end regulation member which regulates a
position in the sheet conveying direction of the sheet; and driving
means for moving said sheet conveying means in the width direction
in the state that the sheet abuts on said sheet conveying
means.
7. An image forming apparatus comprising: an image forming
apparatus main body which has an image forming portion for forming
an image in a sheet; and a sheet treating apparatus according to
claims 1 or 2 which treats the sheet in which the image is formed
by the image forming portion.
8. The image forming apparatus according to claim 7, further
comprising detection means for detecting any one of the end portion
in the width direction of the sheet, a central portion of the
sheet, and an arbitrary position of the sheet, wherein said moving
means moves the sheet in the width direction by a distance
corresponding to a distance between said side-end regulation member
and any one of the end portion in the width direction of the sheet,
the central portion of the sheet, and the arbitrary position of the
sheet.
9. The image forming apparatus according to claim 7, wherein said
moving means moves the sheet in the width direction based on
information on a length in the width direction of the sheet from
said image forming apparatus main body.
10. An image forming apparatus which forms a sheet stack by
aligning sheets conveyed an image forming portion to sheet stacking
means and performs binding treatment to the aligned sheet stack by
binding means, said image forming apparatus comprising: a side-end
regulation member which is provided on a side of a width direction
orthogonal to a sheet conveying direction of said sheet stacking
means, said side-end regulation member regulating an end-portion
position in the width direction of the sheet; and moving means for
moving the sheet in the width direction to cause the sheet to abut
on said side-end regulation member, wherein said moving means moves
the sheet in the width direction to cause the sheet to abut on said
side-end regulation member in each time when the sheet is conveyed
to said sheet stacking means such that the end portions in the
width directions of the sheets whose lengths differ from one
another in the width direction are aligned.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sheet treating apparatus
and an image forming apparatus therewith, particularly to the sheet
treating apparatus and the image forming apparatus therewith, which
perform binding treatment to a sheet stack formed by alignment of
the treated sheets by using binding means.
[0003] 2. Related Background Art
[0004] Conventionally, in the image forming apparatus such as a
copying machine, a printer, and a facsimile, in order to reduce
time and effort necessary for treatments such as binding and
punching to the sheets such as copy paper in which an image is
already formed, some image forming apparatuses includes the sheet
treating apparatus which sequentially takes the sheet to
selectively perform the treatments such as the binding and punching
to the sheet.
[0005] For example, Japanese Patent Application Laid-Open No.
H11-322160 discloses the sheet treating apparatuses in which a
predetermined sheet stack is formed by aligning the sheets
sequentially discharged from the image forming apparatus and
stapling (binding) treatment is performed to the sheet stack.
[0006] In the sheet treating apparatus disclosed in Japanese Patent
Application Laid-Open No. H11-322160, for example, the sheets
sequentially discharged from the image forming apparatus are
temporarily accommodated in a treating tray, the sheets are aligned
to form the sheet stack, the stapling treatment is performed to the
sheet stack by a stapler provided in the treating tray, and the
sheets are discharged from the treating tray to a stack tray to
stack the sheets.
[0007] The conventional sheet treating apparatus and image forming
apparatus therewith include alignment means such as an alignment
plate which aligns the sheets stacked in the treating tray at a
predetermined alignment position before the stapling treatment is
performed. The sheets are aligned at the predetermined alignment
position by the alignment means, which improves appearance of the
sheet stack in which the stapling treatment is performed.
[0008] In performing the alignment of the sheets on the treating
tray, when the discharged sheets have the same sizes, the alignment
operation can be performed with no trouble. However, when the
alignment operation is performed to the sheet stack in which the
sheets having the different sizes are mixed, it is necessary that
the alignment operation is performed by aligning the sheets having
the different sizes with the sheets having a certain size.
[0009] When the alignment operation is performed by aligning the
sheets having the different sizes with the sheet having the maximum
size, because a movement distance to the alignment plate is short
in the maximum-size sheet, when the small-size sheet is moved
toward a direction of the alignment plate by the same amount as for
the maximum-size sheet in aligning the small-size sheet, sometimes
the small-size sheet does not reach the alignment plate. Therefore,
in this case, the sheets cannot securely be aligned.
[0010] When the stapling treatment is performed to the sheet stack
in a state that the sheets are not securely aligned, the stapling
treatment cannot securely be performed to the sheet stack, or the
stapling treatment cannot be performed at an appropriate position
in the sheet stack. Accordingly, there is generated the problem
that the appearance of the sheet stack becomes worsened.
SUMMARY OF THE INVENTION
[0011] In view of the foregoing, an object of the invention is to
provide a sheet treating apparatus and an image forming apparatus
therewith which can securely perform stapling (binding) treatment
even to a sheet stack, in which the sheets having different sizes
are mixed, and improve appearance of the sheet stack when the
stapling (binding) treatment is performed to the sheet stack.
[0012] In order to achieve the object, a sheet treating apparatus
of the invention having sheet stacking means for stacking a sheet
to be treated, the sheet treating apparatus which forms a sheet
stack by aligning the sheets conveyed to the sheet stacking means
and performs binding treatment to the aligned sheet stack by
binding means, the sheet treating apparatus includes a side-end
regulation member which is provided on a side of a width direction
orthogonal to a sheet conveying direction of the sheet stacking
means, the side-end regulation member regulating an end-portion
position in the width direction of the sheet; and moving means for
moving the sheet in the width direction to cause the sheet to
abut-on the side-end regulation member, in which the moving means
moves the sheet in the width direction to cause the sheet to abut
on the side-end regulation member in each time when the sheet is
conveyed to the sheet stacking means such that the end portions in
the width directions of the sheets whose lengths differ from one
another in the width direction are aligned.
[0013] In a sheet treating apparatus according to the invention, it
is possible that the moving means moves the sheet in the width
direction by a distance corresponding to the length in the width
direction.
[0014] In a sheet treating apparatus according to the invention, it
is possible that the sheet treating apparatus further includes
holding means for holding the sheet abutting on the side-end
regulation member, in which the moving means moves the sheet in the
width direction to cause the sheet to abut on the side-end
regulation member in each time when the sheet is conveyed to the
sheet stacking means, in the state that the sheet abutting on the
side-end regulation member is held by the holding means.
[0015] In a sheet treating apparatus according to the invention, it
is possible that the moving means separates the sheet having a
predetermined length in the width direction from the side-end
regulation member by a predetermined distance in the width
direction, after the moving means causes the sheet to abut on the
side-end regulation member.
[0016] In a sheet treating apparatus according to the invention, it
is possible that the binding means is configured to be movable in
the width direction to a predetermined position where the sheets
are bound, the predetermined position being separated from the
side-end regulation member by a predetermined distance.
[0017] In a sheet treating apparatus according to the invention, it
is possible that the moving means includes sheet conveying means
for conveying the conveyed sheet in the opposite direction to the
sheet conveying direction, the sheet conveying means being provided
in a side-end portion on the upstream side in the sheet conveying
direction of the sheet stacking means, the sheet conveying means
causing the sheet to abut on the side-end regulation member which
regulates a position in the sheet conveying direction of the sheet;
and driving means for moving the sheet conveying means in the width
direction in the state that the sheet abuts on the sheet conveying
means.
[0018] Further, an image forming apparatus of the invention
includes an image forming apparatus main body which has an image
forming portion for forming an image in a sheet; and the
above-described sheet treating apparatus which treats the sheet in
which the image is formed by the image forming portion.
[0019] In an image forming apparatus according to the invention, it
is possible that the image forming apparatus further includes
detection means for detecting any one of the end portion in the
width direction of the sheet, a central portion of the sheet, and
an arbitrary position of the sheet, in which the moving means moves
the sheet in the width direction by a distance corresponding to a
distance between the side-end regulation member and any one of the
end portion in the width direction of the sheet, the central
portion of the sheet, and the arbitrary position of the sheet.
[0020] In an image forming apparatus according to the invention, it
is possible that the moving means moves the sheet in the width
direction based on information on a length in the width direction
of the sheet from the image forming apparatus main body.
[0021] Further, an image forming apparatus of the invention which
forms a sheet stack by aligning sheets conveyed an image forming
portion to sheet stacking means and performs binding treatment to
the aligned sheet stack by binding means, the image forming
apparatus includes a side-end regulation member which is provided
on a side of a width direction orthogonal to a sheet conveying
direction of the sheet stacking means, the side-end regulation
member regulating an end-portion position in the width direction of
the sheet; and moving means for moving the sheet in the width
direction to cause the sheet to abut on the side-end regulation
member, in which the moving means moves the sheet in the width
direction to cause the sheet to abut on the side-end regulation
member in each time when the sheet is conveyed to the sheet
stacking means such that the end portions in the width directions
of the sheets whose lengths differ from one another in the width
direction are aligned.
[0022] According to the invention, the sheet is abutted on the
side-end regulation member in each time when the sheet is conveyed
to the sheet stacking means such that the end portions in the width
directions of the sheets whose lengths differ from one another in
the width direction are aligned. Accordingly, the binding treatment
can be performed even to a sheet stack in which the sheets having
different sizes are mixed, and the appearance of the sheet stack
can be improved when the stapling (binding) treatment is performed
to the sheet stack.
[0023] Still other objects of the present invention, and the
features thereof, will become fully apparent from the following
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a sectional view showing a configuration of an
image forming apparatus including a sheet treating apparatus
according to an embodiment of the invention;
[0025] FIG. 2 is a view explaining the configuration of the sheet
treating apparatus;
[0026] FIG. 3 is a view showing a state in which a sheet is
discharged onto a treating tray of the sheet treating
apparatus;
[0027] FIG. 4 is a view explaining offset rollers and conveying
rollers in the sheet treating apparatus;
[0028] FIG. 5 is a view explaining a mechanism for driving the
offset roller, the conveying roller, a sheet stack discharging
member, and a sheet clamping member in the sheet treating
apparatus;
[0029] FIGS. 6A, 6B, and 6C are views explaining operation of the
offset roller and operation of the sheet associated with the
operation of the offset roller;
[0030] FIGS. 7A and 7B are first views explaining the operation of
the sheet clamping member;
[0031] FIGS. 8A and 8B are second views explaining the operation of
the sheet clamping member;
[0032] FIG. 9 is a view showing the state in which the sheet stack
discharge member discharges a sheet stack to a stack tray;
[0033] FIG. 10 is a block diagram showing the configuration of a
control portion of the sheet treating apparatus;
[0034] FIG. 11 is a flowchart explaining a part of sheet treating
operation of the sheet treating apparatus;
[0035] FIG. 12 is a flowchart explaining the remaining parts of the
sheet treating operation of the sheet treating apparatus;
[0036] FIG. 13 is a view showing the state in which a stapling
treatment is performed to the sheets offset by the offset
roller;
[0037] FIG. 14 is a view showing the state in which the stapling
treatment is performed with a stapler unit which can move the
sheets offset by the offset roller in a sheet conveying direction;
and
[0038] FIG. 15 is a view showing the state in which the stapling
treatment is performed with the stapler unit which can move the
sheets offset by the offset roller in a sheet width direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] Referring now to the accompanying drawings, a preferred
embodiment of the invention will be described in detail.
[0040] FIG. 1 is a sectional view showing a configuration of an
image forming apparatus including a sheet treating apparatus
according to an embodiment of the invention. In FIG. 1, the
reference character A denotes an image forming apparatus, the
reference numeral 500 denotes an image forming apparatus main body,
the reference numeral 300 denotes an automatic document feeder
(ADF) provided on an upper surface of the image forming apparatus
main body 500, and the reference numeral 400 denotes a sheet
treating apparatus which treats the sheet discharged from the image
forming apparatus A.
[0041] In FIG. 1, the reference numeral 120 denotes a reader
portion (image input apparatus) which converts the original into
image data, and the reference numeral 200 denotes a printer
portion. The printer portion 200 has sheet cassettes 204 and 205.
The printer portion 200 outputs the image data as a visible image
onto the sheet according to a print command.
[0042] In the image forming apparatus A having the above
configuration, when the original is read to form the image, the
original placed on the auto document feeder (ADF) 300 is conveyed
onto a platen glass surface 102 one by one.
[0043] When the original is conveyed to a predetermined position on
the glass surface 102, a lamp 103 is lit in the reader portion 120,
and a scanner unit 101 is moved to irradiate the original with the
lamp 103. Reflected light from the original is input to a CCD image
sensor portion 109 through mirrors 105, 106, and 107 and a lens
108. Normal digital processing is performed by electric processes
such as optoelectric conversion in the CCD image sensor portion
109.
[0044] The image signal to which the electric processes are
performed is converted into a modulated light signal by an exposure
control portion 201 in the printer portion 200, and a
photosensitive drum 202 is irradiated with the light signal. Then,
a latent image is formed on the photosensitive drum 202 by the
irradiation light. The latent image is developed by a developing
device 203, which allows a toner image to be formed on the
photosensitive drum 202.
[0045] A sheet S is conveyed from the sheet cassette 204 or 205 in
synchronization with a front end of the toner image. The toner
image is transferred to the sheet S with a transfer portion 206.
Then, the toner image transferred to the sheet S is fixed with a
fixing portion 207, and the sheet S to which the toner image is
fixed is discharged outside the apparatus by a sheet discharging
portion 208.
[0046] The sheet S output from the sheet discharging portion 208 is
conveyed to a sheet treating apparatus 400. In the sheet treating
apparatus 400, the sheets S are sorted according to an operation
mode previously specified, and the treatments such as binding are
performed.
[0047] When the images sequentially read are output in both sides
of one sheet S, the sheet S of which the toner image is fixed onto
one side by the fixing portion 207 is guided to a path 215 once by
switching a direction switching member 209 to a direction shown by
broken lines of FIG. 1, and then the sheet S is conveyed to a
turn-over path 212 through a path 218 by switching a direction
switching member 217 to broken lines and by switching a direction
switching member 213 to broken lines.
[0048] After a rear end of the sheet S passes through the direction
switching member 213, the direction switching member 213 is
switched to solid lines to reverse a rotating direction of a roller
211, which guides the sheet S to a path 210. Then, the sheet S is
conveyed to the transfer portion 206 to form the image on the
backside of the sheet S.
[0049] In addition to sorting operation for sorting the sheets S,
the sheet treating apparatus 400 has a stapling function in which a
stapler unit performs binding operation. As shown in FIG. 2, the
sheet treating apparatus 400 includes a treating tray 410 and a
stack tray 421. The treating tray 410 treats the sheets S
sequentially discharged from the image forming apparatus main body
500. The sheet stack treated on the treating tray 410 is finally
stacked on the stack tray. The sheet stack having the number of
sheets corresponding to the number of original sheets is formed on
the treating tray 410, and each sheet stack is discharged to the
stack tray 421.
[0050] In FIG. 2, the reference numeral 401 denotes a sheet
receiving portion which receives the sheet S discharged from the
image forming apparatus main body 500. After the sheet receiving
portion 401 receives the sheet S, the sheet S is detected by an
entrance sensor 403, and the sheet S is conveyed by conveying
rollers 405 and offset rollers 407. Then, as shown in FIG. 3, the
sheet S is conveyed onto the treating tray 410 which is of sheet
stacking means. The sheet S stacked on the treating tray 410 is
detected by a sheet stack discharge sensor 415 shown in FIG. 2.
[0051] At this point, the offset rollers 407 which are of sheet
conveying means is held about an offset roller arm 406 in the state
being able to be lifted and lowered. The offset roller arm 406 is
vertically movable about a shaft 406a shown in FIGS. 4 and 5. When
the sheet S is conveyed to the treating tray 410, the offset
rollers 407 are moved upward through the offset roller arm 406,
which allows the sheet S to be conveyed onto the treating tray 410
without being interrupted by the offset rollers 407.
[0052] The offset roller arm 406 can be lifted and lowered by a
pickup solenoid 433 while the shaft 406a acts as a fulcrum. That
is, the offset rollers 407 are lifted and lowered through a down
lever 433a by turning on and off the pickup solenoid 433.
[0053] As shown in FIG. 5, the offset rollers 407 are driven
through belts 431a and 431b by the conveying motor 431. The
conveying motor 431 also drives the conveying rollers 405. When the
conveying motor 431 is rotated, the offset rollers 407 are rotated
(hereinafter, referred to as reversely rotated) in a conveying
direction or the reverse direction according to the amount of
rotation of the conveying motor 431.
[0054] In the embodiment, the entrance sensor 403 detects the sheet
S, and the pickup solenoid 433 is turned off after the sheet S is
moved to a predetermined position away from the entrance sensor
403. Therefore, the offset rollers 407 are lowered by deadweight to
land on the sheet S. Then, the offset rollers 407 are rotated in a
conveying direction for a predetermined time, and the offset
rollers 407 are reversely rotated after the predetermined time
elapses.
[0055] The reverse rotation allows the sheet S to abut on a sheet
rear-end stopper 411 to perform alignment of the sheet S in the
conveying direction. The sheet rear-end stopper 411 is of a
side-end regulation member for regulating the position of the sheet
S in the conveying direction. The sheet rear-end stopper 411 is
vertically provided on the upstream side in the conveying direction
of the treating tray 410.
[0056] In FIG. 4, the reference numeral 416 denotes a positioning
wall which is of the side-end regulation member for regulating the
end position of the sheet S in direction (hereinafter referred to
as width direction) orthogonal to the conveying direction of the
sheet S. The reference numeral 420 denotes a stapler unit which is
of binding means for performing stapling treatment to the sheet
stack formed on the treating tray 410. The stapler unit 420 is
arranged near the positioning wall of the treating tray 410. An
offset motor 432, which is of driving means and can rotate and
reversely rotate, drives the offset rollers 407 through a rack 406c
and a pinion 406a. Therefore, the offset rollers 407 can be moved
in the width direction to be brought close to the positioning wall
416. The offset motor 432 and the offset rollers 407 constitute
moving means.
[0057] When the offset rollers 407 are brought close to the
positioning wall 46, the sheet S in which the alignment of the
conveying direction is performed by abutting on the sheet rear-end
stopper 411 is moved to the positioning wall 416 by frictional
force of the offset rollers 407, and the sheet S is positioned in
the width direction. After the sheet S abuts on the positioning
wall 416, the offset rollers 407 are moved while sliding on the
sheet S, and then the offset rollers 407 are stopped.
[0058] Thus, since the offset rollers 407 are provided, as shown in
FIG. 6A, the sheet S discharged on the treating tray 410 is
conveyed toward the stack tray side by the offset rollers 407
rotated in the sheet conveying direction. Then, as shown in FIG.
6B, the sheet S is returned to the sheet rear-end stopper 411 by
the reverse rotation of the offset rollers 407, and the rear end of
the sheet S abuts on the sheet rear-end stopper 411 to perform the
alignment of the sheet S.
[0059] FIGS. 6A, 6B, 6C, 7A, 7B, 8A and 8B, and 13 differ from FIG.
4 in the configuration in which the offset rollers 407 are arranged
inside the offset roller arm 406. However, the difference is only
the design matter. Accordingly, for the configurations shown in
FIGS. 4, 6A, 6B, 6C, 7A, 7B, 8A and 8B, and 13, there is no
difference in the functions and operations.
[0060] Then, as shown in FIG. 6C, the offset rollers 407 are moved
along the shaft 406a toward the positioning wall side in the state
being in contact with the sheet S, which allows the end portion in
the width direction of the sheet S to abut on the positioning wall
416 to perform the alignment in the width direction of the sheet
S.
[0061] In FIG. 5, the reference numeral 412 denotes a sheet
clamping member which is of sheet stack holding means. The sheet
clamping member 412 presses the rear-end portion of the aligned
sheet S from the upper side by bias force generated by biasing
means (not shown). As mentioned later, the alignment in the width
direction of the sheet S is performed, and the rear-end alignment
of the sheet S is performed. Then, when the offset rollers 407 is
lifted by the pickup solenoid 433 as shown in FIG. 7A, the aligned
sheet S is pressed from the upper side by the sheet clamping member
412 as shown in FIG. 7B.
[0062] The sheet S previously discharged (conveyed) to the treating
tray 410 can be held at a predetermined position while the
previously discharge sheet S is not affected by pull-in of the
sheets S subsequently discharged (conveyed).
[0063] When the offset rollers 407 are reversely rotated, as shown
in FIG. 8A, the sheet clamping member 412 is rotated upward so that
the sheet S can be received. When the sheet S and the offset
rollers 407 are moved in the width direction in order to perform
the alignment of the end portion of the sheet S, as shown in FIG.
8B, the sheet clamping member 412 is rotated upward so as not to
become a load against the movement of the sheet S.
[0064] In FIG. 5, the reference numeral 413 denotes sheet stack
discharging member which is cited as an example of sheet stack
discharging means. The sheet stack discharging member 413
discharges the treated sheet stack to the stack tray 421. The sheet
stack discharging member 413 rotatably holds the sheet clamping
member 412. In the state that the sheet clamping member 412 holds
the aligned sheet stack or the sheet stack stapled after the
alignment, the sheet stack discharging member 413 moves the sheet
stack toward the stack tray 421 provided on the downstream side of
the treating tray 410 as shown in FIG. 9.
[0065] When the sheet S reaches a front end portion of the treating
tray 410 which is of a sheet discharging position shown by the
solid line, a sheet stack SA on the stack tray 421 is released from
the hold of the sheet clamping member 412, and the sheet stack SA
is discharged and stacked on the stack tray 421. The sheet stack SA
discharged and stacked on the stack tray 421 is held by a pressing
member 421A shown in FIG. 2.
[0066] As shown in FIG. 5, a sheet stack discharging motor 430
transmits power to the sheet stack discharging member 413 through
the rack and pinion, which allows the sheet stack discharging
member 413 to travel between the position where the sheet S is
discharged to the stack tray 421 and a home position near the sheet
rear-end stopper 411. Usually the sheet stack discharging member
413 is fixed at the home position by magnetic excitation of the
sheet stack discharging motor 430.
[0067] In FIG. 5, the reference numeral 434 denotes a clamping
solenoid which rotates the sheet clamping member 412. The clamping
solenoid 434 is turned on after the offset rollers 407 convey the
sheet S, the clamping solenoid 434 is turned on when the offset
rollers 407 stop the rotation, and the clamping solenoid 434 is
turned on when the offset rollers 407 are moved in the width
direction. The clamping solenoid 434 rotates the sheet clamping
member 412 upward through a lever 434a and a releasing lever
portion 412a provided in the sheet clamping member 412.
[0068] In the embodiment, after the sheet S is moved in the width
direction, in order to correct the shift in the sheet conveying
direction, the offset rollers 407 are reversely rotated again to
end the alignment operation, which realizes the alignment with high
accuracy. When the alignment treatment is ended for the specified
number of sheets, the sheet clamping member 412 is closed by the
clamping solenoid 434 to hold the sheet stack.
[0069] FIG. 10 is a block diagram showing the configuration of a
control portion of the sheet treating apparatus 400. The reference
numeral 100 denotes a CPU which is cited as an example of
controlling means in the embodiment. The CPU 100 has a ROM 110. A
program corresponding to a control procedure shown in FIGS. 11 and
12 and the like are stored in the ROM 110. The CPU 100 controls
each portion while reading the program.
[0070] A RAM 121 is incorporated in the CPU 100. Action data and
input data are stored in the RAM 121. The CPU 100 controls based on
the program while referring to the data stored in the RAM 121.
Input ports of the CPU 100 are connected to sensors such as the
entrance sensor 403 and the sheet stack discharge sensor 415.
Output ports of the CPU 100 are connected to motors and solenoids
such as the conveying motor 431, the offset motor 432, the sheet
stack discharging motor 430, the pickup solenoid 433, and the
clamping solenoid 434. The CPU 100 controls loads of various motors
and solenoids, which are connected to the output ports, based on
the states of the sensors according to the program.
[0071] The CPU 100 includes a serial interface portion (I/O) 130.
The serial interface portion (I/O) 130 transmits control data to
and receives the control data from (a control portion of) the image
forming apparatus main body 500, and the CPU 100 controls each
portion based on the control data transmitted from (the control
portion of) the image forming apparatus main body 500 through the
serial interface portion (I/O) 130.
[0072] Because the image forming apparatus main body 500 grasps a
size of the sheet S discharged from the sheet discharging portion
208, the control portion of the sheet treating apparatus 400 (CPU
100) including a microcomputer system conducts serial communication
with the control portion of the image forming apparatus main body
500, which allows the size of the sheet S inserted on the treating
tray 410 to be grasped.
[0073] Accordingly, the control portion of the sheet treating
apparatus 400 (CPU 100) grasps the size of the sheet S in each time
when the sheet S is discharged (conveyed) from the image forming
apparatus main body, and the CPU 100 can control the amount of
movement in the width direction of the offset rollers 407 by
controlling the offset motor 432. Therefore, the offset rollers 407
can be moved by the amount according to the size of the sheet S
inserted on the treating tray 410, and the side portion of the
sheet S is abutted securely on the positioning wall 416.
[0074] In the embodiment, the sheet stack SA stacked on the stack
tray 421 constitutes a part of the treating tray 410. Therefore,
when the sheet stack SA is discharged from the treating tray 410,
the stack tray 421 is lowered by a stack tray lifting/lowering
motor (see FIG. 10) until the uppermost surface of the sheet stack
SA stacked on the stack tray 421 corresponds substantially to the
treating tray 410.
[0075] Then, sheet treating operation of the embodiment as
configured above will be described referring to a flowchart shown
in FIGS. 11 and 12.
[0076] When the image forming apparatus main body 500 starts the
image forming operation, the CPU 100 of the sheet treating
apparatus 400 (see FIG. 10) checks whether a sheet discharging
signal is received from the image forming apparatus main body 500
or not (S100). When the sheet discharging signal is received (Y in
S100), the pickup solenoid 433 is turned on (S110) to pull up the
offset rollers 407 supported by the offset roller arm 406.
[0077] Then, the conveying motor 431 is turned on (S120) so that
the conveying rollers 405 installed at a midpoint of a sheet
discharging path can convey the sheet S in the direction similar to
the sheet discharging direction of the image forming apparatus main
body 500. When the front end of the initial sheet S passes through
the entrance sensor 403, the entrance sensor 403 is turned on (Y in
S130). Then, the sheet S reaches the conveying rollers 405, which
allows the power to be transmitted from the conveying rollers 405.
When the sheet S is separated from the sheet discharging portion
208 (see FIG. 1) in the image forming apparatus main body 500 (Y in
S140), the delivery of the sheet S is completed.
[0078] While the conveying rollers 405 convey the sheet S to the
treating tray 410, the pickup solenoid 433 is turned off (S150)
before the sheet S passes completely through the conveying rollers
405. Then, the offset rollers 407 are caused to land on the sheet S
by the deadweight. As shown in FIG. 6A, the offset rollers 407
convey the sheet S to the predetermined position (S160). When the
sheet S is conveyed to the predetermined position (Y in S160), the
rotation of the conveying motor 431 is stopped (S170), and the
conveyance of the sheet S is stopped.
[0079] The clamping solenoid 434 is turned on at the time when the
rotation of the offset rollers 407 is stopped (S180), and the sheet
clamping member 412 installed at the home position near the sheet
rear-end stopper 411 is opened as shown in FIG. 6B. Then, the
conveying motor 431 is rotated in the opposite direction to the
conveying direction to pull back the sheet S with the offset
rollers 407 (S190), and the rear end of the sheet S is abutted on
the sheet rear-end stopper 411.
[0080] In causing the rear end of the sheet S to abut on the sheet
rear-end stopper 411, in consideration of skew of the sheet S
generated when the sheet S is conveyed from the image forming
apparatus main body 500, the amount of rotation of the offset
rollers 407 is set so that the sheet S can be conveyed slightly
longer than the distance between a point where the conveyance of
the sheet S is stopped to perform switchback and the sheet rear-end
stopper 411.
[0081] The size of the discharged sheet S is checked based on size
information from the image forming apparatus main body 500 (S200),
and the amount of offset movement according to the size of the
discharged sheet S is computed. That is, the amount of offset
movement which is of the amount of movement in the width direction
of the sheet S is computed (S210). The amount of movement in the
width direction of the sheet S is necessary for pressing the sheet
S discharged on the treating tray 410 against the positioning wall
416.
[0082] The offset motor 432 is driven to start the offset movement
of the offset rollers 407 (S220). In moving the offset rollers 407,
the offset rollers 407 and the sheet S which is in contact with the
offset rollers 407 are moved in the direction of the positioning
wall 416 by the frictional force of the offset rollers 407. At this
point, as shown in FIG. 8B, the sheet clamping member 412 is
rotated upward so that the sheet clamping member 412 does not
become the load against the movement of the sheet S.
[0083] As shown in FIG. 6C, the sheet S abuts on the positioning
wall 416 by the offset movement operation of the offset rollers
407, which performs the alignment in the width direction of the
sheet S. After the offset rollers 407 causes the sheet S to abut on
the positioning wall 416, the offset rollers 407 is slightly moved
while sliding on the sheet S and the offset rollers 407 is stopped.
In order to correct the alignment shift in the conveying direction
after the offset movement, the alignment operation in which the
offset rollers 407 are reversely rotated again to pull back the
sheet S is performed (S230), and the alignment of the first sheet S
is completed.
[0084] When the alignment of the first sheet S is completed, the
pickup solenoid 433 is turned on (S240) to lift the offset rollers
407 as shown in FIG. 7A, and the clamping solenoid 434 is turned
off (S250). Therefore, as shown in FIG. 7B, the sheet clamping
member 412 is closed the sheet S in which the alignment has been
performed is nipped and held. As a result, the pull-in of the first
discharge sheet by the subsequently discharged sheet S can be
prevented.
[0085] Then, as shown in 7B, the offset rollers 407 are returned
and moved to the home position by the offset motor 432 through the
rack and pinion in the state being lifted (S260).
[0086] It is checked whether or not the sheet S accommodated on the
treating tray 410 is the final sheet corresponding to the final
page of the original to be copied (S270). When determined based on
the information transmitted from the image forming apparatus main
body 500 that the sheet S is not the final sheet S (N in S270), the
flow returns to S100, and a sheet discharging signal sent from the
image forming apparatus main body 500 is received. The flow is
repeated until the final sheet S is accommodated in the treating
tray 410.
[0087] In the configuration of the embodiment, the control portion
(CPU 100) of the sheet treating apparatus 400 computes the amount
of offset movement suitable for the sheet S while grasping the size
of the sheet S at each time when the sheet S is discharged from the
image forming apparatus main body 500. Accordingly, the sheet S
with which the offset rollers 407 are in contact is subjected to
the alignment treatment based on the computed amount of movement,
and the sheet S is aligned with the positioning wall 416.
[0088] When determined that the sheet S is the final sheet S (Y in
S270), since the sheet stack corresponding to the original to be
copied is formed on the treating tray 410, it is checked whether
the stapling treatment is selected or not (S280). When the stapling
treatment is selected (Y in S280), the staple unit 420 is driven to
perform the stapling treatment at a staple position shown in FIG.
13 (S290).
[0089] As shown in FIG. 13, even if the sheets S1 and S2 whose
sizes differ from each other are mixed in the sheet stack stacked
on the treating tray 410, each of the sheets S1 and S2 is subjected
to the alignment treatment according to the size, so that the each
of the sheets S1 and S2 is aligned with the positioning wall 416.
Because the alignment position is one in which corner portions of
the sheets S1 and S2 are inserted into the binding portion (not
shown) of the stapler unit 420, the binding treatment is securely
performed by the subsequent stapling treatment.
[0090] When the stapling treatment is not selected (N in S280), or
after the stapling treatment is completed, the sheet stack
discharging motor 430 causes the sheet stack discharging member 413
to proceed toward the direction of the stack tray 421 in the state
that the sheet stack SA is held by the sheet clamping member 412,
and the sheet stack SA is discharged (S300).
[0091] The movement (lowering) process of the stack tray 421 is
performed in synchronization with the sheet stack discharging
operation (S310), and the sheet stack discharging member 413 is
returned to the home position (S320). In order to stop the rotation
of the conveying rollers 405 and offset rollers 407, the conveying
motor 431 is stopped (S330) and the pickup solenoid 433 is turned
off (S340), which lowers the offset rollers 407 to end the series
of the treatments.
[0092] As described above, in each time when the sheet S is
conveyed to the stack tray 421, the offset rollers 407 causes the
sheet S to abut on the positioning wall 416 to align the end
portions in the width directions of the sheets S whose lengths in
the width directions differ from one another. Therefore, even if
the sheet stack SA includes the sheets S whose sizes differ from
one another, the binding treatment is securely performed and the
appearance of the sheet stack SA becomes better when the binding
treatment is performed to the sheet stack SA. In moving the sheet S
in the width direction to abut on the positioning wall 416, since
the sheet S previously aligned is held by the sheet clamping member
412, disorder of the alignment is never generated.
[0093] In the embodiment, the fixed type stapler unit 420 for
binding the sheet stack SA is used, and the stapler unit 420 is
arranged near the positioning wall 416. The invention is not
limited to the embodiment. It is also possible to use the movable
type stapler unit 420 which can be moved in the sheet conveying
direction or in the width direction.
[0094] When the movable type stapler unit 420 which can be moved in
the sheet conveying direction is used, as shown in FIG. 14, the
stapling treatment can be performed at another point in the sheet
conveying direction of the sheet stack SA or at plural points in
the sheet conveying direction.
[0095] When the movable type stapler unit 420 which can be moved in
the width direction is used, the stapling treatment can be
performed at another point in the width direction of the sheet
stack SA or at plural points in the width direction. After the
offset rollers 407 causes the sheet S having the predetermined size
to abut on the positioning wall 416, the sheet S is separated from
the positioning wall 416 to the wide direction in accordance with
sheet size, and the movable type stapler unit 420 which can be
moved in the width direction is moved to the predetermined position
in the width direction. Therefore, as shown in FIG. 15, the sheet
stack SA in which the sheets S1, S2, and S3 having the different
sizes are mixed can be bound with respect to the center, and the
appearance of the sheet stack SA becomes better when the binding
treatment is performed.
[0096] In the embodiment, the offset rollers 407 is used as the
sheet conveying means, the offset motor 432 is used as the driving
means, and the sheet conveying means and the driving means
constitute the moving means for moving the sheet S in the width
direction. The invention is not limited to the embodiment. The same
effects are obtained, when the moving means is constituted by the
sheet conveying means for moving the member itself in the conveying
direction to convey the sheet and the driving means for moving the
sheet conveying means in the width direction.
[0097] In the embodiment, the CPU controls while reading the
program written on the RAM (or the ROM), which is shown in the
flowchart of FIGS. 11 and 12. However, the same effects are
obtained when hardware performs the processes on the control
program.
[0098] In the embodiment, the amount of offset movement is computed
based on the sheet size information which is of the length
information in the width direction of the sheet S discharged from
the image forming apparatus main body 500. The invention is not
limited to the embodiment. For example, the same effects are
obtained, when detection means for detecting the length in the
width direction of the sheet is provided in the sheet treating
apparatus 400 to control the amount of offset movement of the
offset roller 407 according to a detection signal from the
detection means.
[0099] Further, foe example, the detection means for detecting any
one of the end portion in the width direction of the sheet, the
central portion of the sheet, and an arbitrary position of the
sheet is provided, and the offset rollers 407 are moved in response
to the detection signal from the detection means by the distance
between the positioning wall 416 and any one of the end portion in
the width direction of the sheet, the central portion of the sheet,
and an arbitrary position of the sheet. Therefore, the same effects
are obtained.
[0100] In the above descriptions, the CPU of the control portion
provided in the sheet treating apparatus in the image forming
apparatus controls the operations of the offset rollers and the
like. It is also possible that the CPU of the control portion is
provided in the image forming apparatus main body and the CPU
controls the sheet treating operations of the offset rollers and
the like.
[0101] The present invention has been explained by preferred
embodiments thereof, but the present invention is by no means
limited by such embodiments and is subject to any and all
modifications within the scope and spirit of the appended
claims.
[0102] This application claims priority from Japanese Patent
Application No. 2004-122290 filed Apr. 16, 2004, which is hereby
incorporated by reference herein.
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