U.S. patent application number 17/360305 was filed with the patent office on 2021-12-30 for sheet conveying apparatus.
This patent application is currently assigned to CANON FINETECH NISCA INC.. The applicant listed for this patent is Toshiyuki IWATA, Tetsuya KAWASAKI, Tsukasa KONDO, Yuuki KUBOTA. Invention is credited to Toshiyuki IWATA, Tetsuya KAWASAKI, Tsukasa KONDO, Yuuki KUBOTA.
Application Number | 20210403262 17/360305 |
Document ID | / |
Family ID | 1000005735294 |
Filed Date | 2021-12-30 |
United States Patent
Application |
20210403262 |
Kind Code |
A1 |
IWATA; Toshiyuki ; et
al. |
December 30, 2021 |
SHEET CONVEYING APPARATUS
Abstract
In order to provide a configuration capable of correcting skew
and lateral displacement of a sheet, a pair of regulation guides
are capable of guiding opposite end edges in a sheet width
direction of a sheet S conveyed by a conveyance belt and spheres,
while being nipped. Further, the pair of regulation guides are
capable of shifting to guide positions for guiding the opposite end
edges of the sheet, and retract positions retracted from the
opposite end edges of the sheet more than the guide positions,
wherein a control section conveys the sheet by the conveyance belt
in a state in which the pair of regulation guides are positioned in
the retract positions, and brings a front end of the sheet in a
state of being conveyed by the conveyance belt into contact with a
conveyance roller pair with drive halted.
Inventors: |
IWATA; Toshiyuki; (Tokyo,
JP) ; KONDO; Tsukasa; (Minamikoma-gun, JP) ;
KAWASAKI; Tetsuya; (Minamikoma-gun, JP) ; KUBOTA;
Yuuki; (Minamikoma-gun, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IWATA; Toshiyuki
KONDO; Tsukasa
KAWASAKI; Tetsuya
KUBOTA; Yuuki |
Tokyo
Minamikoma-gun
Minamikoma-gun
Minamikoma-gun |
|
JP
JP
JP
JP |
|
|
Assignee: |
CANON FINETECH NISCA INC.
Misato-shi
JP
|
Family ID: |
1000005735294 |
Appl. No.: |
17/360305 |
Filed: |
June 28, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 9/002 20130101 |
International
Class: |
B65H 9/00 20060101
B65H009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2020 |
JP |
2020-112403 |
Jun 4, 2021 |
JP |
2021-094029 |
Claims
1. A sheet conveying apparatus which receives and conveys a sheet
conveyed by a conveyance member for conveying the sheet in a
predetermined conveyance direction, comprising: an endless
conveyance belt disposed on a downstream side of the conveyance
member in the conveyance direction to include a conveyance face
extended in the conveyance direction and to convey the sheet
delivered to the conveyance face in the conveyance direction; a
plurality of spheres disposed in positions opposed to the
conveyance face in the conveyance direction to be rotatable in any
direction, while nipping the sheet between the spheres and the
conveyance face; a conveyance roller pair disposed on the
downstream side of the conveyance belt in the conveyance direction
to be able to convey the sheet; a pair of regulation guides
disposed on opposite sides of the conveyance belt with respect to a
sheet width direction crossing the conveyance direction to be able
to guide opposite end edges in the sheet width direction of the
sheet conveyed by the conveyance belt and the spheres, while being
nipped; a guide shift section capable of shifting the pair of
regulation guides to guide positions for guiding the opposite end
edges of the sheet in the sheet width direction and retract
positions retracted from the opposite end edges of the sheet in the
sheet width direction more than the guide positions; and a control
section adapted to control the conveyance belt, the conveyance
roller pair and the guide shift section, wherein in conveying the
sheet, the control section is capable of executing a mode for
conveying the sheet by the conveyance belt in a state in which the
pair of regulation guides are positioned in the retract positions,
positioning the pair of regulation guides from the retract
positions to the guide positions after bringing a front end of the
sheet in a state of being conveyed by the conveyance belt into
contact with the conveyance roller pair with drive halted, and
subsequently, driving the conveyance roller pair to convey the
sheet to the downstream side in the conveyance direction.
2. The sheet conveying apparatus according to claim 1, wherein in
executing the mode, the control section positions the pair of
regulation guides from the retract positions to the guide
positions, and subsequently, after driving the conveyance roller
pair to start conveyance of the sheet to the downstream side in the
conveyance direction by the conveyance roller pair, shifts the pair
of regulation guides from the guide positions to the retract
positions.
3. The sheet conveying apparatus according to claim 1, wherein the
guide positions are positions where a distance between the pair of
regulation guides is longer than a length of the sheet in the sheet
width direction by a predetermined length.
4. The sheet conveying apparatus according to claim 1, wherein in
conveying the sheet, when a length of the sheet in the conveyance
direction is a first length, the control section executes the mode,
while when the length of the sheet in the conveyance direction is a
second length longer than the first length, the control section
shifts the pair of regulation guides from the retract positions to
the guide positions, while conveying the sheet by the conveyance
belt, and delivers the sheet from the conveyance belt to the
conveyance roller pair, without halting drive of the conveyance
roller pair.
5. The sheet conveying apparatus according to claim 1, wherein in
conveying the sheet, when weighing of the sheet is first weighing,
the control section executes the mode, while when the weighing of
the sheet is second weighing larger than the first weighing, the
control section shifts the pair of regulation guides from the
retract positions to the guide positions, while conveying the sheet
by the conveyance belt, and delivers the sheet from the conveyance
belt to the conveyance roller pair, without halting drive of the
conveyance roller pair.
Description
TECHNICAL FIELD
[0001] The present invention relates to a sheet conveying apparatus
for conveying sheets.
BACKGROUND ART
[0002] In a sheet conveying apparatus for conveying sheets, there
is the risk that misregistration such as skew of a sheet occurs due
to various factors during conveyance of the sheet. The skew is that
the sheet is inclined with respect to a sheet conveyance direction.
Then, while the misregistration occurs, for example, in the case of
conveying to an image forming apparatus for forming an image on the
sheet, the inconvenience occurs such that the image is displaced
with respect to the sheet.
[0003] Therefore, there is a disclosed configuration for correcting
skew of a sheet by causing the sheet to strike a register roller
pair (e.g., Japanese Unexamined Patent Publication No.
2004-106995). In this configuration, the sheet is continued to be
fed by a conveyance roller pair on the upstream side in a state in
which a sheet front end is truck by the register roller pair, and
by rotating the register roller pair after forming a loop in the
sheet, the skew of the sheet is corrected.
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0004] In the case of the sheet conveying apparatus described in
Japanese Unexamined Patent Publication No. 2004-106995, it is
possible to correct the skew of the sheet as described above, but
it is not possible to correct lateral displacement of the sheet
i.e. it is not possible to correct that the sheet is displaced in a
width direction and is conveyed.
[0005] It is an object of the present invention to provide a
configuration capable of correcting skew and lateral displacement
of a sheet.
Means for Solving the Problem
[0006] In the present invention, a sheet conveying apparatus which
receives and conveys a sheet conveyed by a conveyance member for
conveying the sheet in a predetermined conveyance direction is
provided with an endless conveyance belt disposed on the downstream
side of the conveyance member in the conveyance direction to
include a conveyance face extended in the conveyance direction and
to convey the sheet delivered to the conveyance face in the
conveyance direction, a plurality of spheres disposed in positions
opposed to the conveyance face in the conveyance direction to be
rotatable in any direction, while nipping the sheet between the
spheres and the conveyance face, a conveyance roller pair disposed
on the downstream side of the conveyance belt in the conveyance
direction to be able to convey the sheet, a pair of regulation
guides disposed on opposite sides of the conveyance belt with
respect to a sheet width direction crossing the conveyance
direction to be able to guide opposite end edges in the sheet width
direction of the sheet conveyed by the conveyance belt and the
spheres, while being nipped, a guide shift section capable of
shifting the pair of regulation guides to guide positions for
guiding the opposite end edges of the sheet in the sheet width
direction and retract positions retracted from the opposite end
edges of the sheet in the sheet width direction more than the guide
positions, and a control section for controlling the conveyance
belt, the conveyance roller pair and the guide shift section, where
in conveying the sheet, the control section is capable of executing
a mode for conveying the sheet by the conveyance belt in a state in
which the pair of regulation guides are positioned in the retract
positions, positioning the pair of regulation guides from the
retract positions to the guide positions after bringing a front end
of the sheet in a state of being conveyed by the conveyance belt
into contact with the conveyance roller pair with drive halted, and
subsequently, driving the conveyance roller pair to convey the
sheet to the downstream side in the conveyance direction.
[0007] According to the present invention, it is possible to
correct skew and lateral displacement of the sheet.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a schematic configuration cross-sectional view of
an image forming system according to an Embodiment;
[0009] FIG. 2 is a perspective view of a relay conveying apparatus
according to the Embodiment;
[0010] FIG. 3 is a plan view of the relay conveying apparatus
according to the Embodiment; FIG. 4 is a side elevational view of
the relay conveying apparatus according to the Embodiment;
[0011] FIG. 5 is a cross-sectional view of the relay conveying
apparatus according to the Embodiment;
[0012] FIG. 6A is a perspective view of a regulation guide
according to the Embodiment; FIG. 6B is a view of the guide looking
from the left side in FIG. 6A; FIG. 6C is a cross-sectional view of
the guide taken in a direction along a conveyance direction of a
sheet; FIG. 6D is a cross-sectional view of the guide taken in a
direction orthogonal to the conveyance direction of the sheet;
[0013] FIG. 7 is a perspective view illustrating a
contact-separation mechanism of conveyance rollers according to the
Embodiment;
[0014] FIG. 8A is a side elevational view illustrating a nip state
of the conveyance rollers of the contact-separation mechanism of
conveyance rollers according to the Embodiment; FIG. 8B is a side
elevational view illustrating a nip release state of the conveyance
rollers;
[0015] FIG. 9 is a block diagram in relation to sheet conveyance
control according to the Embodiment;
[0016] FIGS. 10A to 10C contain schematic views in the relay
conveying apparatus according to the Embodiment, where FIG. 10A
illustrates a state in which a sheet is delivered to a conveyance
belt, FIG. 10B illustrates a state in which the sheet is struck by
a conveyance roller pair, and FIG. 10C illustrates a state in which
a pair of regulation guides are positioned in guide positions;
[0017] FIGS. 11A and 11B contain schematic views in the conveying
apparatus according to the Embodiment, where FIG. 11A illustrates a
state of conveying a sheet with a long sheet length, and FIG. 11B
illustrates a state of conveying a sheet with a short sheet
length;
[0018] FIG. 12 is a flowchart in relation to sheet conveyance
control according to the Embodiment; and
[0019] FIGS. 13A and 13B contain schematic views in a sheet
conveying apparatus according to a comparable example, where FIG.
13A illustrates a state in which a sheet is struck by a register
roller pair, and FIG. 13B illustrates a state in which a loop is
formed in the sheet.
MODE FOR CARRYING OUT THE INVENTION
[0020] An Embodiment will be described with reference to FIGS. 1 to
13B. First, an image forming system of this Embodiment will be
described with reference to FIG. 1.
[Image Forming System]
[0021] FIG. 1 is a cross-sectional view schematically showing one
example of an image forming system provided with a multi-stage feed
apparatus and image forming apparatus according to this Embodiment.
In the following description, as the image forming apparatus
including an image forming section, a laser printer system
(hereinafter, simply called a printer) using an electrophotographic
scheme will be described as an example. In addition, as well as the
printer, the image forming apparatus constituting the image forming
system may be a copier, facsimile, composite machine and the like.
Further, the image forming apparatus is not limited to the
electrophotographic scheme, and may be a configuration of another
scheme such as an ink jet scheme.
[0022] The image forming system 1000 of this Embodiment includes an
image forming apparatus 100, a multi-stage feed apparatus 200
connected to the image forming apparatus 100 as a sheet feed
apparatus, and a feed deck 500. As described later in detail, the
multi-stage feed apparatus 200 includes a plurality of storage
chambers each capable of storing a plurality of sheets, and is
capable of feeding a sheet from each of the storage chambers to the
image forming apparatus 100. Further, the feed deck 500 also
includes a storage chamber capable of storing a plurality of
sheets, and is disposed on the upstream side of the multi-stage
feed apparatus 200 with respect to a sheet conveyance direction.
Further, the sheet fed from the feed deck 500 is conveyed to the
image forming apparatus 100 via a relay conveying apparatus 400
provided in the multi-stage feed apparatus 200. In addition, as
sheets, there are papers such as normal paper, thin paper and thick
paper, plastic sheets and the like.
[0023] The image forming apparatus 100 forms a toner image (image)
on a sheet corresponding to an image signal from a document reading
apparatus 102 connected to an image forming apparatus main body
101, or a host apparatus such as a personal computer connected to
the image forming apparatus main body 101 to be communicable and
the like. In the case of this Embodiment, the document reading
apparatus 102 is disposed on the image forming apparatus main body
101.
[0024] In reading a document, the document reading apparatus 102
irradiates the document placed on platen glass 103 with light by a
scanning optical system light source, while inputting reflected
light to a CCD, and thereby reads a document image. Further, the
document reading apparatus 102 is provided with an automatic
document feeder (ADF) 104, and is also able to read a document
image by automatically conveying a document placed on a tray 105 to
a reading section of the document reading apparatus 102 by the ADF
104. Then, the read document image is converted into an electric
signal, and is transmitted to a laser scanner 113 of an image
forming section 110 described later. In addition, there is also the
case where image data transmitted from the personal computer or the
like as described above is input to the laser scanner 113.
[0025] The image forming apparatus 100 is provided with the image
forming section 110, a plurality of sheet feed apparatuses 120,
sheet conveying apparatus 130 and the like. In the image forming
apparatus 100, a control section 140 controls each section. The
control section 140 has a CPU (Central Processing Unit), ROM (Read
Only Memory), and RAM (Random Access Memory). The CPU reads
programs that correspond to control procedures stored in the ROM to
control each section. Further, in the RAM is stored operation data
and input data, and the CPU performs control by referring to the
data stored in the RAM, based on the programs and the like
described previously.
[0026] Each of the plurality of sheet feed apparatuses 120 is
provided with a cassette 121 for storing sheets S, a pick-up roller
122, and a separation conveyance roller pair 125 comprised of a
feed roller 123 and retard roller 124. The sheets S stored inside
the cassette 121 are separated and fed on a sheet-by-sheet basis,
by the pick-up roller 122 for performing up-and-down operation and
rotating at predetermined timing, and the separation conveyance
roller pair 125.
[0027] The sheet conveying apparatus 130 is provided with a
conveyance roller pair 131, and register roller pair 133. The sheet
S fed from the sheet feed apparatus 120 is passed through a sheet
conveyance path 134 by the conveyance roller pair 131, and then, is
guided to the register roller pair 133. Subsequently, the sheet S
is sent to the image forming section 110 at predetermined timing by
the register roller pair 133.
[0028] In addition, the sheet, which is conveyed from the
multi-stage feed apparatus 200 described later and the feed deck
500 via a conveyance roller pair 201, is conveyed into the image
forming apparatus 100 via a connection path 202 with the image
forming apparatus 100. Then, the sheet, which is conveyed from the
multi-stage feed apparatus 200 and the feed deck 500 into the image
forming apparatus 100, is sent into the image forming section 110
at predetermined timing via the register roller pair 133, as the
sheet conveyed from the sheet feed apparatus 120 inside the image
forming apparatus 100.
[0029] The image forming section 110 is provided with a
photosensitive drum 111, charger 112, laser scanner 113, developing
device 114, transfer apparatus 115, cleaner 117 and the like. At
the time of image formation, the photosensitive drum 111 is driven
to rotate in the arrow direction shown in the figure, and first, a
surface of the photosensitive drum 111 is uniformly charged by the
charger 112. Then, the charged photosensitive drum 111 is
irradiated with laser light from the laser scanner 113 emitted
corresponding to the image signal, and an electrostatic latent
image is thereby formed on the photosensitive drum 111. Further,
the electrostatic latent image thus formed on the photosensitive
drum 111 is subsequently developed as a toner image by the
developing device 114.
[0030] Subsequently, the toner image on the photosensitive drum 111
is transferred to the sheet S by the transfer apparatus 115 in a
transfer section 116. Further, the sheet S with the toner image
thus transferred is conveyed to a fuser apparatus 150 to fuse the
toner image, and then, is discharged to a discharge tray 152
outside the apparatus by a discharge roller 151.
[0031] In the case where a toner image is formed on the backside of
the sheet S, the sheet S discharged from the fuser apparatus 150 is
conveyed to a reverse conveyance path 160. Then, in a state in
which the side is reversed by the reverse conveyance path 160, the
sheet S is conveyed again to the transfer section 116 of the image
forming section 110. The sheet S with the toner image transferred
to the backside is conveyed to the fuser apparatus 150, and after
fusing the toner image, is discharged to the discharge tray 152 by
the discharge roller 151. In addition, after transferring, transfer
residual toner left on the photosensitive drum 111 is removed by
the cleaner 117.
[Multi-Stage Feed Apparatus]
[0032] Successively, the outline of the multi-stage feed apparatus
200 will be described with reference to FIG. 1. The multi-stage
feed apparatus 200 is provided with a plurality of storage chambers
210a to 210c, relay conveying apparatus 400 and the like. In this
Embodiment, three storage chambers 210a to 210c are arranged
vertically in three stages, and the relay conveying apparatus 400
is disposed between the lowermost storage chamber 210c and the
second uppermost storage chamber 210b.
[0033] A sheet fed from the uppermost storage chamber 210a is
conveyed to a conveyance path 212, a sheet fed from the second
uppermost storage chamber 210b is conveyed to a conveyance path
213, and a sheet fed from the lowermost storage chamber 210c is
conveyed to a conveyance path 214. Further, a sheet conveyed from
the relay conveying apparatus 400 is conveyed to a conveyance path
215. The conveyance path 213 merges with the conveyance path 212 at
some midpoint. Further, the conveyance paths 212, 214 and 215 merge
at a confluence 216, and the sheet is conveyed to the conveyance
roller pair 201 through a conveyance path 217, and is conveyed to
the image forming apparatus 100 via the connection path 202.
[0034] Further, a multi feed detecting sensor for detecting multi
feed of sheets is disposed in each of the conveyance path 212
merged with the conveyance path 213, the relay conveying apparatus
400 and the conveyance path 214. Then, sheets with multi feed
detected by the multi feed detecting sensor are conveyed to the
conveyance path 217. Below the conveyance path 217 is disposed a
multi feed sheet storage section (escape tray) 218 for storing
sheets with multi feed detected. The sheets with multi feed
detected are conveyed to the conveyance path 217, and are conveyed
to the multi feed sheet storage section, by switching between
conveyance paths by a switch member 219 provided in the conveyance
path 217.
[0035] Further, in the multi-stage feed apparatus 200, a control
section 203 controls each section. The control section 203 has a
CPU (Central Processing Unit), ROM (Read Only Memory), and RAM
(Random Access Memory). Further, the control section 203 is capable
of communicating with the control section 140 of the image forming
apparatus 100, and by communicating with the control section 140,
controls feed timing of the sheet and the like.
[0036] The sheet fed from the feed deck 500 on the upstream side
passes through a conveyance path 512, and is conveyed to the relay
conveying apparatus 400. Further, the multi-stage feed apparatus
200 enables a sheet manually inserted to be also fed. The manually
fed sheet is conveyed to a conveyance path 510 merging with the
conveyance path 512, and is conveyed to the relay conveying
apparatus 400 via the conveyance path 512 by a conveyance roller
pair 511.
[0037] Although details will be described next, the relay conveying
apparatus 400 is provided with a misregistration correcting section
410 provided with a conveyance belt 12 and the like, a conveyance
roller pair 401 on the upstream side of the misregistration
correcting section 410 in the sheet conveyance direction, a
conveyance roller pair 402 on the downstream side of the
misregistration correcting section 410 in the sheet conveyance
direction, and the like. The sheet conveyed in the conveyance path
512 is fed to the misregistration correcting section 410 by the
conveyance roller pair 401. After correcting side registration
(misregistration of end edges in the sheet width direction, lateral
displacement) and side skew (skew of the end edge of the sheet in
the width direction with respect to the sheet conveyance direction,
skew) in the misregistration correcting section 410, the sheet is
delivered to the conveyance roller pair 402 on the downstream side.
Then, the sheet is conveyed to the conveyance path 215 by the
conveyance roller pairs 402, 403. Thus, the relay conveying
apparatus 400 corrects misregistration and so on of the sheet
conveyed from the feed deck 500 and the like on the upstream side,
and delivers to the image forming apparatus 100 on the downstream
side.
[Relay Conveying Apparatus]
[0038] The relay conveying apparatus 400 as a sheet conveying
apparatus will be described next. First, a schematic configuration
of the relay conveying apparatus 400 will be described with
reference to FIGS. 2 to 5. The relay conveying apparatus 400
includes the conveyance roller pair 401 on the upstream side, the
conveyance roller pair 402 on the downstream side, the
misregistration correcting section 410 described above and the
like, and conveys the sheet in a conveyance direction X. The
misregistration correcting section 410 has the conveyance belt 12,
a plurality of spheres 20, a pair of regulation guides 14A, 14B,
guide shift section 420 and the like.
[0039] The conveyance belt 12 is disposed downstream (downstream in
the conveyance direction) in the conveyance direction X from the
conveyance roller pair 401 as a conveyance member for conveying the
sheet. The conveyance belt 12 is an endless belt looped between
pulleys 11A, 11B, and has a conveyance face 12A provided to extend
along the conveyance direction X. To the pulley 11A on one side is
connected a motor M1 as a drive source, and the conveyance belt 12
rotates by drive of the motor Ml. Such a conveyance belt 12
conveys, in the direction X, the sheet delivered from the
conveyance roller pair 401 on the upstream side in the conveyance
direction X to the conveyance face 12A.
[0040] A plurality of spheres 20 is disposed along the conveyance
direction X in positions opposed to the conveyance face 12A of the
conveyance belt 12. In this Embodiment, the plurality of spheres 20
is disposed above the conveyance belt 12. The plurality of spheres
20 is capable of rotating in any direction, while nipping the sheet
with the conveyance face 12A. Therefore, each of the plurality of
spheres 20 is held in a hold plate 18 provided above the conveyance
belt 12 rotatably in any direction. In other words, as shown in
FIGS. 2 and 3, the hold plate 18 is a long plate disposed along the
conveyance direction X in a position spaced a predetermined
distance apart from the conveyance face 12A above the conveyance
belt 12, and has a plurality of hold holes 18A at a distance from
one another in the conveyance direction X. Then, the hold holes 18A
hold the spheres 20 rotatably, respectively.
[0041] As shown in FIG. 4, the sphere 20 is exposed from the hold
hole 18A, is placed on the conveyance face 12A of the conveyance
belt 12, and is made rotatable in any direction. Each of the
spheres 20 is brought into contact with the conveyance face 12A
under its own weight. In addition, the number of spheres 20 may be
set corresponding to a pressing force required for the sheet
conveyed on the conveyance belt 12. Further, since the sheet is
conveyed, while slipping on the conveyance belt 12 as described
later, the sphere 20 is preferably comprised of a material such as
glass and plastic with a relatively low coefficient of friction. In
addition, this Embodiment describes the configuration where the
plurality of spheres 20 is arranged in a single line along the
conveyance direction X, and a plurality of spheres 20 may be
arranged and disposed in each of a plurality of lines such as two
lines in the conveyance direction X.
[0042] A pair of regulation guides 14A, 14B are disposed on
opposite sides of the conveyance belt 12, with respect to the sheet
width direction Y (in this Embodiment, direction orthogonal to the
conveyance direction) crossing the conveyance direction X. Then,
the pair of regulation guides 14A, 14B are capable of guiding
opposite end edges (opposite end edges in the sheet width
direction) in the sheet width direction Y of the sheet that is
conveyed by the conveyance belt 12 and the sphere 20, while being
nipped. In other words, the regulation guide 14A, which is disposed
on one side (front side of the apparatus) with respect to the sheet
width direction Y, is capable of guiding the end edge on one side
in the sheet width direction of the sheet that is conveyed by the
conveyance belt 12 and the sphere 20, while being nipped. Further,
the regulation guide 14B, which is disposed on the other side (rear
side of the apparatus) with respect to the sheet width direction Y,
is capable of guiding the end edge on the other side in the sheet
width direction of the sheet that is conveyed by the conveyance
belt 12 and the sphere 20, while being nipped. In addition, the one
side (front side) in the sheet width direction Y is the side to
operate the image forming system 1000.
[0043] As shown in FIG. 5, each of the pair of regulation guides
14A, 14B includes a side plate portion 15, lower plate portion 16,
and upper plate portion 17, and enables the end portion of the
sheet S conveyed by the conveyance belt 12 to enter a space
surrounded by the plate portions 15, 16 and 17. The pair of
regulation guides 14A, 14B are supported by support shafts 421A,
421B (see FIG. 3) to be able to shift to guide positions and
retract positions by the guide shift section 420 described later.
Each of the support shafts 421A, 421B is disposed substantially
parallel with the sheet width direction Y, and supports end portion
sides of the pair of regulation guides 14A, 14B in the conveyance
direction X. The pair of regulation guides 14A, 14B are capable of
shifting in the sheet width direction Y along the support shafts
421A, 421B.
[0044] The side plate portion 15 has a guide face 15A opposed to
the end edge (end edge in the sheet width direction) in the sheet
width direction Y of the sheet S that is conveyed by the conveyance
belt 12 and the sphere 20, while being nipped, in the guide
position. The guide face 15A is disposed parallel with the
conveyance direction X. Further, the guide face 15A is a face
orthogonal to each of the conveyance direction X and the sheet
width direction Y, and in this Embodiment, is a face along the
substantially vertical direction.
[0045] The lower plate portion 16 has a support face 16A which is
disposed to be orthogonal to the side plate portion 15, and
supports the end edge in the sheet width direction Y of the sheet S
that is conveyed by the conveyance belt 12 and the sphere 20, while
being nipped, in the guide position. The support face 16A is
provided to extend substantially in the horizontal direction from a
lower end portion of the guide face 15A in the vertical direction.
Further, the support face 16A is positioned below the conveyance
face 12A of the conveyance belt 12 in the vertical direction.
[0046] Herein, the case is considered where the support face 16A
and conveyance face 12A are the same height, or the support face
16A is positioned above the conveyance face 12A in the vertical
direction. In this case, when a sheet S such as thick paper with
high stiffness is conveyed to between the conveyance belt 12 and
the sphere 20 in a downward curled state (state in which the
opposite end edges in the width direction Y are lower than the
center) as shown in FIG. 5, the opposite end edges of the sheet S
in the width direction Y are supported by the support faces 16A. At
this point, the center portion of the sheet S in the width
direction Y is in a state of being raised (in a bridged state), and
pushes the sphere 20 up. As a result, the conveyance belt 12 and
the sphere 20 are in a separate state, and there is the risk that
the conveyance force of the conveyance belt 12 is not transferred
to the sheet S, and that a conveyance failure occurs. Therefore, in
this Embodiment, the support face 16A is disposed below the
conveyance face 12A of the conveyance belt 12 in the vertical
direction.
[0047] The upper plate portion 17 has an opposed face 17A disposed
opposite the support face 16A. The opposed face 17A is positioned
above the end edge in the sheet width direction Y of the sheet S
that is conveyed by the conveyance belt 12 and the sphere 20, while
being nipped, in the guide position. Further, the opposed face 17A
is formed substantially parallel with the support face 16A.
[0048] As shown in FIGS. 2 and 3, the guide shift section 420 as a
guide shift section has a first shift section 420A for shifting the
regulation guide 14A on one side in the pair of regulation guides
14A, 14B, and a second shift section 420B for shifting the
regulation guide 14B on the other side. Further, the guide shift
section 420 has a motor M2 for generating a driving force to shift
the regulation guide 14A, and a motor M3 for generating a driving
force to shift the regulation guide 14B on the other side.
[0049] The first shift section 420A has a pair of pulleys 422A,
423A, an endless belt 424A looped between both of the pulleys 422A,
423A, and a connection portion 425A for connecting between the belt
424A and the regulation guide 14A. Similarly, the second shift
section 420B has a pair of pulleys 422B, 423B, an endless belt 424B
looped between both of the pulleys 422B, 423B, and a connection
portion 425B for connecting between the belt 424B and the
regulation guide 14B on the other side.
[0050] Further, as shown in FIG. 2, the first shift section 420A is
driven by the motor M2 as a drive source, and the second shift
section 420B is driven by the motor M3 as a drive source. In other
words, in the case of this Embodiment, different motors are used as
drive sources for shifting the pair of regulation guides 14A, 14B,
respectively, and the pair of regulation guides 14A, 14B are
capable of shifting independently of each other. Therefore, the
pulley 422A of the first shift section 420A is coupled to a pulley
427A via a coupling shaft 426A, and a belt 428A is looped between
the pulley 427A and a pulley driven to rotate by the motor M2.
Then, rotation drive of the motor M2 is transferred to the belt
424A via the belt 428A, pulley 427A, coupling shaft 426A, and
pulley 422A. As described above, since the belt 424A is connected
to the regulation guide 14A via the connection portion 425A, by
drive of the motor M2, the regulation guide 14A shifts in the sheet
width direction Y along the support shafts 421A, 421B.
[0051] Similarly, the pulley 422B of the second shift section 420B
is coupled to a pulley 427B via a coupling shaft 426B, and a belt
428B is looped between the pulley 427B and a pulley driven to
rotate by the motor M3. Then, rotation drive of the motor M3 is
transferred to the belt 424B via the belt 428B, pulley 427B,
coupling shaft 426B, and pulley 422B. As described above, since the
belt 424B is connected to the regulation guide 14B on the other
side via the connection portion 425B, by drive of the motor M3, the
regulation guide 14B on the other side shifts in the sheet width
direction Y along the support shafts 421A, 421B.
[0052] By thus driving the motors M2, M3, the regulation guides
14A, 14B are shifted to the guide positions and retract positions,
respectively. In the case of this Embodiment, each of the motors
M2, M3 is a pulse motor (stepping motor), and a position of each of
the regulation guides 14A, 14B is controlled by the number of
pulses sent to the motor, respectively. Further, each of the
regulation guides 14A, 14B has a home position, and a sensor for
detecting each of the regulation guides 14A, 14B is provided in the
home position, respectively. Therefore, positions of the regulation
guides 14A, 14B are detected in home positions, and subsequently,
using the number of pulses sent to the motor, each of the
regulation guides 14A, 14B is shifted to the guide position and the
retract position.
[0053] In addition, in the case of this Embodiment, the motor M1
for driving the conveyance belt 12 described above, the motors M2,
M3 for shifting the regulation guides 14A, 14B, and motors M5, M7,
M8 described later are disposed on the other-side regulation guide
14B side. Particularly, with respect to the conveyance direction X,
motors within a conveyance range of the sheet of the
misregistration correcting section 410 are preferably disposed on
the rear side of the conveyance belt 12 (the other-side regulation
guide 14B side). This is because the case of this Embodiment is
configured to remove a jammed sheet from the front side (one-side
regulation guide 14A side).
[0054] Further, in the case of this Embodiment, as shown in FIGS. 3
and 4, a multi feed detecting sensor 430 for detecting multi feed
of sheets is disposed between the conveyance roller pair 401 on the
upstream side and the conveyance belt 12. For example, the multi
feed detecting sensor 430 is a sensor for detecting that two or
more sheets are stacked and conveyed by an ultrasonic wave. In the
case of detecting multi feed of sheets by the multi feed detecting
sensor 430, the control section 203 (FIG. 1) of the multi-stage
feed apparatus 200 conveys the multi-fed sheets to the multi feed
sheet storage section 218 via the relay conveying apparatus 400,
and the conveyance paths 215, 217.
[0055] Further, as shown in FIG. 4, the relay conveying apparatus
400 of this Embodiment has a plurality of sheet detecting sensors
433, 435, 436 to detect a jam of a sheet. In addition, the jam of a
sheet is that the sheet remains in the conveyance path by jamming
or the like. The sheet detecting sensor 433 as an upstream-side
sheet detecting section is disposed on the upstream side (upstream
side in the conveyance direction) of the conveyance belt 12 in the
conveyance direction X, and detects the presence or absence of the
sheet. The sheet detecting sensor 433 is disposed between the
conveyance belt 12 and the conveyance roller pair 401.
[0056] The sheet detecting sensor 435 is disposed on the downstream
side (downstream side in the conveyance direction) of the
conveyance belt 12 in the conveyance direction X, and detects the
presence or absence of the sheet. The sheet detecting sensor 435 is
disposed between the conveyance roller pair 402 and the conveyance
roller pair 403 disposed on the downstream side of the conveyance
belt 12. The sheet detecting sensor 436 is disposed on the
downstream side of the sheet detecting sensor 435 in the conveyance
direction X, and detects the presence or absence of the sheet. The
sheet detecting sensor 436 is disposed downstream of the conveyance
roller pair 403. The sheet detecting sensors 435, 436 correspond to
downstream-side detecting sections.
[0057] Based on detection signals of various sheet detecting
sensors such as the sheet detecting sensors 433, 435, 436, the
control section 203 (FIG. 1) of the multi-stage feed apparatus 200
determines whether or not a sheet is jammed in the conveyance path.
Then, in the case where the control section 203 determines that the
sheet is jammed, the section 203 halts conveyance of the sheet, and
displays the jam of the sheet and a portion of the jam on a display
section such as a liquid crystal panel provided in the image
forming system 1000. At this point, the section urges an operator
such as a user and service person to open a door of the
corresponding portion.
[0058] Further, in the case of this Embodiment, as shown in FIG. 3,
with respect to the sheet width direction Y, opposed members 450,
460 opposed to the backside of the sheet conveyed by the conveyance
belt 12 are disposed between the conveyance belt 12 and the pair of
regulation guides 14A, 14B. In the case where an end portion of a
sheet is conveyed, without being supported by any of the regulation
guides 14A, 14B, the opposed members 450, 460 support the end
portion of the sheet.
[0059] The relay conveying apparatus 400 thus configured nips the
sheet delivered from the conveyance roller pair 401 upstream in the
conveyance direction X to the conveyance belt 12 with the
conveyance belt 12 and the sphere 20. Then, the sheet is conveyed
by rotation of the conveyance belt 12. At this point, although
details will be described later, the apparatus causes the opposite
ends in the width direction Y of the sheet conveyed by the
conveyance belt 12 to strike the guide faces 15A of the pair of
regulation guides 14A, 14B. When the sheet is struck by the guide
faces 15A, the sheet is conveyed in a direction parallel with the
guide faces 15A, while causing the opposite side ends to move along
the guide faces 15A and slipping between the conveyance belt 12 and
the face. At this point, the sheet is nipped by the conveyance belt
12 and the sphere 20, and since the sphere 20 is rotatable in any
direction, is capable of shifting, while slipping on the conveyance
belt 12 in any direction. By this means, the side registration and
side skew of the sheet is corrected.
[Regulation Guide]
[0060] Next, descriptions will be given to the detailed
configuration of the pair of regulation guides 14A, 14B, with
reference to FIGS. 6A to 6D. In addition, although FIGS. 6A to 6D
illustrate only the regulation guide 14A on one side, the
regulation guide 14B on the other side also has the same
configuration. As shown in FIG. 5, the regulation guide 14A
includes the side plate portion 15 having the guide face 15A, the
lower plate portion 16 having the support face 16A, and the upper
plate portion 17 having the opposed face 17A.
[0061] As shown in FIGS. 6A and 6B, the lower plate portion 16 and
upper plate portion 17 are provided continuously over almost the
entire area in the longitudinal direction of the regulation guide
14A. As shown in FIG. 2 and so on, since the regulation guide 14A
is disposed substantially parallel with the conveyance direction X,
a predetermined region A refers to a range where the lower plate
portion 16 and upper plate portion 17 are continuous with respect
to the conveyance direction X. Accordingly, in this Embodiment, the
support face 16A of the lower plate portion 16 and the opposed face
17A of the upper plate portion 17 are provided continuously over
the predetermined region A with respect to the conveyance direction
X. The predetermined region A is almost the entire area of the
region where the sheet is conveyed by the misregistration
correcting section 410.
[0062] On the other hand, as shown in FIGS. 6A to 6C, the side
plate portion 15 is provided continuously over a guide region B
that is a region shorter than the predetermined region A. In this
Embodiment, an upstream end (upstream end in the conveyance
direction) B1 of the side plate portion 15 in the conveyance
direction X is positioned on the downstream side from an upstream
end Al of the predetermined region A in the conveyance direction X.
In other words, the upstream end B1 of the guide face 15A of the
side plate portion 15 in the conveyance direction X is positioned
on the downstream side from the upstream end Al of the
predetermined region A. Further, with respect to the conveyance
direction X, the guide face 15A is provided continuously up to a
downstream end A2 of the predetermined region A. Accordingly, a
position of a downstream end B2 of the side plate portion 15 in the
conveyance direction X and a position of the downstream end A2 of
the predetermined region A in the conveyance direction X are almost
the same position with respect to the conveyance direction X.
[0063] In this Embodiment, a notch 19C is provided on the upstream
side from the upstream end B1 of the side plate portion 15. Then,
in a part of the notch 19C is disposed an outer plate portion 19
positioned on the outer side of the side plate portion 15 in the
sheet width direction Y. The outer side in the sheet width
direction Y is a side spaced apart from the conveyance belt 12 with
respect to the sheet width direction Y. Therefore, as shown in FIG.
6C, an inner face 19A of the outer plate portion 19 is positioned
on the outer side in the sheet width direction Y than the guide
face 15A that is the inner face of the side plate portion 15.
Further, with respect to the conveyance direction X, between the
outer plate portion 19 and the side plate portion 15 is provided an
inclined plate portion 19B inclined closer to the side plate
portion 15, as going downstream.
[0064] Each of the pair of regulation guides 14A, 14B is configured
as described above, and a distance in the width direction Y between
the inner faces 19A of the outer plate portions 19 on the upstream
side in the conveyance direction X is thereby wider than a distance
in the width direction Y between the guide faces 15A of the side
plate portions 15. Therefore, as described later in detail, the
opposite end edges in the width direction Y of the sheet delivered
from the conveyance roller pair 401 on the upstream side to the
conveyance belt 12 are positioned between the inner faces 19A on
the upstream side in the conveyance direction X, and by conveying
to the downstream side, are positioned between the guide faces
15A.
[0065] In addition, the outer plate portion 19 and inclined plate
portion 19B may be omitted. However, in the case where the end
portion in the width direction Y of the sheet delivered from the
conveyance roller pair 401 on the upstream side to the conveyance
belt 12 is positioned inside the notch 19C, when the sheet is
further conveyed, there is the risk that the end portion of the
sheet is caught in the upstream end B1 of the side plate portion
15. Therefore, in this Embodiment, the outer plate portion 19 and
inclined plate portion 19B are provided, and it is configured that
also in the case where the sheet is conveyed, while being displaced
from a normal position in the width direction Y, the outer plate
portion 19 regulates a position of the sheet, and that the inclined
plate portion 19B further guides the end portion of the sheet to
the guide face 15A of the side plate portion 15.
[Contact-Separation Configuration of the Conveyance Roller
Pair]
[0066] Next, referring to FIGS. 1 and 2, the contact-separation
configuration of the conveyance roller pairs 401 to 403 will be
described using FIGS. 7, 8A and 8B. As described above, each of the
conveyance roller pairs 401 to 403 is disposed upstream or
downstream of the conveyance belt 12 in the conveyance direction X.
Each of the conveyance roller pairs 401 to 403 has a drive roller
32 and driven roller 33 as a pair of conveyance rollers. The drive
roller 32 is an elastic roller where an elastic body such as rubber
is provided around a rotation shaft 32a. The driven roller 33 comes
into contact with the drive roller 32 to form the nip portion for
nipping the sheet to convey. The drive roller 32 of the conveyance
roller pair 401, the drive roller 32 of the conveyance roller pair
402, and the drive roller 32 of the conveyance roller pair 403 are
capable of being driven to rotate independently of one another, by
a motor M4, motor M5 and motor M6, respectively.
[0067] In this Embodiment, the conveyance roller pairs 402, 403
disposed on the downstream side (downstream side in the conveyance
direction) of the conveyance belt 12 in the conveyance direction X
have the configuration for enabling the drive roller 32 and driven
roller 33 to come into contact and separate with/from each other.
By a motor M7 and motor M8, the conveyance roller pairs 402, 403
enable the drive roller 32 and driven roller 33 to come into
contact and separate with/from each other independently,
respectively. Since configurations of the conveyance roller pairs
402, 403 are the same, the contact-separation configuration will be
described below using the conveyance roller pair 402 as an example,
with reference to FIGS. 7, 8A and 8B.
[0068] A contact-separation mechanism 31 for causing the drive
roller 32 and driven roller 33 to come into contact and separate
with/from each other has a compression spring 34 as a biasing
member, support member 35, motor M7, separation cam 36 and link
member 37. The contact-separation mechanism 31 corresponds to a
roller shift section for enabling at least one of the pair of
conveyance rollers i.e. the driven roller 33 to shift to a nip
position for enabling a sheet to be nipped and conveyed, and a nip
release position where the pair of conveyance rollers are separate
from the nip position.
[0069] The compression spring 34 is a spring for biasing the driven
roller 33 toward the drive roller 32. The support member 35
supports a rotation shaft 33a of the driven roller 33, and is
supported swingably around a swing shaft 37a as the center.
Further, the support member 35 is biased by the compression spring
34 in a direction for pressing the driven roller 33 to the drive
roller 32 with the swing shaft 37a as the center. The support
member 35 is fixed to the swing shaft 37a, rotates together with
the swing shaft 37a, and shifts the driven roller 33 in a direction
for approaching the drive roller 32 and in a direction for
separating from the drive roller 32.
[0070] The motor M7 drives the separation cam 36 to rotate via
pulleys 38a, 38b, and a belt 38c. The pulley 38a is fixed to a
drive shaft of the motor M7, and the pulley 38b is fixed to a
rotation shaft 36a of the separation cam 36. The belt 38c is an
endless belt looped between the pulleys 38a, 38b. The separation
cam 36 is an eccentric cam that the center of the outer
circumferential surface is eccentric from the center of the
rotation shaft 36a, and rotates together with the rotation shaft
36a by drive of the motor M7.
[0071] The link member 37 is fixed to the swing shaft 37a, and is
provided swingably together with the swing shaft 37a. Accordingly,
the link member 37 rotates in synchronization with the support
member 35 via the swing shaft 37a. The link member 37 is disposed
to come into contact with the separation cam 36, by the support
member 35 being biased by the compression spring 34.
[0072] In the case where the separation cam 36 is in a phase shown
in FIG. 8A, the driven roller 33 is brought into press-contact with
the drive roller 32 by the biasing force of the compression spring
34. The state of FIG. 8A is the nip position. From this state, for
example, when the separation cam 36 is driven to rotate 180.degree.
by the motor M7, as shown in FIG. 8B, the link member 37 is pressed
by the separation cam 36 to swing around the swing shaft 37a as the
center in a counterclockwise direction in the figure. Then, the
support member 35 coupled to the link member 37 via the swing shaft
37a swings around the swing shaft 37a as the center in the same
direction. The driven roller 33 is supported by the support member
35 via the rotation shaft 33a, and therefore, by the swing of the
support member 35, separates from the drive roller 32. In other
words, the driven roller 33 is shifted to the nip release
position.
[0073] In the case of shifting the driven roller 33 from the nip
release position to the nip position, the separation cam 36 is
further rotated 180.degree. from the state of FIG. 8B by the motor
M7. In addition, the contact-separation mechanism for causing the
drive roller 32 and driven roller 33 to come into contact and
separate with/from each other may be a configuration for shifting
both the drive roller 32 and the driven roller 33. Further, in the
above-mentioned example, the contact-separation mechanism is driven
by the motor, and contact and separation of a pair of conveyance
rollers may be performed by another drive source such as a
solenoid.
[0074] Further, in the above-mentioned example, the conveyance
roller pairs 402, 403 on the downstream side of the conveyance belt
12 in the conveyance direction X are allowed to come into contact
and separate, and only the conveyance roller pair 402 may be
allowed to come into contact and separate. Further, the conveyance
roller pair 401 on the upstream side of the conveyance belt 12 in
the conveyance direction X may be allowed to come into contact and
separate. In this case, only the conveyance roller pair 401 on the
upstream side may be allowed to come into contact and separate, and
also the conveyance roller pair 402 on the downstream side and
further, also the conveyance roller pair 403 may be allowed to come
into contact and separate.
[Control Configuration of Sheet Conveyance Operation]
[0075] Next, descriptions will be given to a control configuration
for various motors and various sensors in control of sheet
conveyance operation in the relay conveying apparatus 400 in this
Embodiment with reference to FIG. 9. A control board of the control
section 203 has a CPU (or ASIC) 230, motor driver 231, and sensor
input circuit 232. The CPU 230 performs detection of sheet
conveyance timing, sheet jam and the like, using output signals
from the sheet detecting sensors 433, 434, 435 and the like.
Particularly, in this Embodiment, based on output signals from the
sheet detecting sensors 433, 434, 435, the CPU 230 performs control
of various motors M1 to M6. As described above, the motor M1 drives
the conveyance belt 12, the motors M2, M3 shift the pair of
regulation guides 14A, 14B, the motor M4 drives the conveyance
roller pair 401, the motor M5 drives the conveyance roller pair
402, and the motor M6 drives the conveyance roller pair 403.
[Conveyance Operation for Sheets]
[0076] Next, referring to FIGS. 2 to 4, 9 and so on, a specific
example of control of conveyance operation for sheets will be
described. In this Embodiment, the control section 203 as the
control section controls the conveyance belt 12, conveyance roller
pair 402 and guide shift section 420, and corrects lateral
displacement and skew of the sheet delivered from the conveyance
roller pair 401 on the upstream side to the conveyance belt 12. The
conveyance roller pair 402 disposed on the downstream side of the
conveyance belt 12 in the conveyance direction X corresponds to a
register roller pair which the sheet strikes in a state in which
drive is halted. Further, actually, as shown in FIG. 9, the control
section 203 controls the motor M1 for driving the conveyance belt
12, the motors M2, M3 to shift the pair of regulation guides 14A,
14B, and the motor M5 for driving the conveyance roller pair
402.
[0077] Specifically, the section 203 controls the motors M2, M3
corresponding to a conveyance state of the sheet, and changes
positions of the pair of regulation guides 14A, 14B in the sheet
width direction Y. As described above, by controlling the motors
M2, M3, and thereby driving the guide shift section 420 (FIG. 2),
it is possible to shift the pair of regulation guides 14A, 14B to
the guide positions and retract positions.
[0078] Herein, the guide positions are positions for enabling the
guide faces 15A of the pair of regulation guides 14A, 14B to guide
the end edges in the width direction Y of the sheet that is
conveyed by the conveyance belt 12 and the sphere 20, while being
nipped. In this Embodiment, the guide positions are positions where
a distance between the guide faces 15A (between the guide faces) of
the pair of regulation guides 14A, 14B is longer than a length in
the sheet width direction Y of the sheet that is conveyed by the
conveyance belt 12 and the sphere 20, while being nipped by a
predetermined length.
[0079] Specifically, in a state in which a center position of the
sheet in the width direction Y coincides with a center position
between the guide faces 15A on the opposite sides and in a state in
which the end edges of the sheet in the width direction Y are
parallel with the guide faces 15A (center reference), when the
sheet is conveyed, the guide positions are positions where a
predetermined distance is made between the end edge of the sheet in
the width direction Y and the guide face 15A. The predetermined
distance is capable of being set as appropriate according to the
apparatus, and is a distance capable of permitting displacement
between the sheet and an image formed on the sheet when the sheet
is displaced within the distance. For example, the predetermined
distance is 0.5 mm. In other words, in the guide positions, the
guide faces 15A of the pair of regulation guides 14A, 14B are in
positions spaced 0.5 mm apart from the end edges of the sheet in
the width direction Y, respectively. The control section 203 is
capable of modifying the guide position as appropriate
corresponding to the sheet size.
[0080] Thus, in the guide positions, since the pair of regulation
guides 14A, 14B are positioned in the positions where the distance
between the guide faces 15A of the pair of regulation guides 14A,
14B is longer than the length of the sheet in the sheet width
direction Y, it is possible to suppress a conveyance load of the
sheet conveyed by the conveyance belt 12. For example, in the case
where the distance between the guide faces is the same as the
length of the sheet in the width direction Y, the sheet is conveyed
with the end portions of the sheet rubbing against the guide faces,
and conveyance resistance is increased. Particularly, in this
Embodiment, since the sheet is nipped and conveyed by the
conveyance belt 12 and the sphere 20, the nip pressure for nipping
the sheet by the conveyance belt 12 and the sphere 20 is low.
Therefore, when the conveyance resistance of the sheet is high,
there is the risk that a conveyance failure tends to occur such
that a delay occurs in conveyance of the sheet, and that conveyance
of the sheet is halted. Therefore, in this Embodiment, by
positioning the pair of regulation guides 14A, 14B in the guide
positions as described above, it is configured to suppress the
conveyance resistance of the sheet.
[0081] In addition, it is preferable to correct (perform alignment
operation) the lateral displacement and skew of the sheet as
described later, by conveying the sheet with the center reference
as described above. This is because in this Embodiment, the
correction of the skew is made, by slipping the sheet between the
conveyance belt 12 and the sphere 20 and rotating the sheet. In
other words, by starting the alignment operation in the position
(center reference) where the center of gravity of the sheet S
substantially coincides with the center portion of the regulation
guides 14A, 14B, it is possible to reduce damage to the sheet in
the alignment operation.
[0082] On the other hand, the retract positions are positions where
the guide faces 15A of the pair of regulation guides 14A, 14B are
retracted from the end edges of the sheet in the width direction Y
more than the guide positions. In other words, the distance in the
width direction Y between the guide faces 15A of the pair of
regulation guides 14A, 14B in the retract positions is wider than
the distance in the width direction Y between the guide faces 15A
of the pair of regulation guides 14A, 14B in the guide
positions.
[0083] In this Embodiment, the retract position is a position where
a distance is 5 mm from the end edge in the width direction Y of
the sheet conveyed with the above-mentioned center reference. In
addition, the sheet S is delivered to the conveyance belt 12 in a
state in which the regulation guides 14A, 14B are in the retract
positions, and in this state, a shift of the sheet S in the
vertical direction is regulated by the support faces 16A and
opposed faces 17A. By this means, even in the case where the sheet
S is curled, when the regulation guides 14A, 14B shift from the
retract positions to the guide positions, it is possible to
accommodate the opposite end edges of the sheet S within the region
surrounded by the guide faces 15A, support faces 16 and opposed
faces 17A.
[0084] In this Embodiment, in the sheet alignment operation, the
control section 203 is capable of executing a first mode and a
second mode. In the first mode, the section 203 shifts the pair of
regulation guides 14A, 14B from the retract positions to the guide
positions, while conveying a sheet by the conveyance belt 12, and
without halting drive of the conveyance roller pair 402 on the
downstream side, delivers the sheet from the conveyance belt 12 to
the conveyance roller pair 402.
[0085] On the other hand, in the second mode, in conveying a sheet,
the section 203 conveys the sheet by the conveyance belt 12 in a
state in which the pair of regulation guides 14A, 14B are
positioned in the retract positions. In other words, in the state
in which the pair of regulation guides 14A, 14B are positioned in
the retract positions, the sheet is delivered from the conveyance
roller pair 401 on the upstream side to the conveyance belt 12. At
this point, the section 203 halts drive of the conveyance roller
pair 402 on the downstream side. Then, the front end of the sheet
in a state of being conveyed by the conveyance belt 12 is brought
into contact with the conveyance roller pair 402 with the drive
halted. Subsequently, the section 203 positions the pair of
regulation guides 14A, 14B from the retraction positions to the
guide positions, and then, drives the conveyance roller pair 402 to
convey the sheet to the downstream side in the conveyance
direction.
[0086] In other words, in the second mode, after causing the sheet
to strike the conveyance roller pair 402 on the downstream side
with the drive halted, the section 203 shifts the pair of
regulation guides 14A, 14B from the retraction positions to the
guide positions. In contrast thereto, in the first mode, for a
period during which the sheet is conveyed by the conveyance belt
12, the section 203 shifts the pair of regulation guides 14A, 14B
from the retraction positions to the guide positions. Further, in
the first mode, the section 203 performs neither halting of the
conveyance roller pair 402 on the downstream side, nor the
operation for causing the sheet to strike the conveyance roller
pair 402. The modes will specifically be described below.
[First Mode]
[0087] First, in the first mode, in the case of conveying a sheet
from the conveyance roller pair 401 on the upstream side to the
conveyance belt 12, the pair of regulation guides 14A, 14B are
shifted to the retract positions. This is because in the case where
the pair of regulation guides 14A, 14B are in the guide positions
at the time the sheet S1 is delivered to the conveyance belt 12,
when the sheet is skewed and/or misregistered in the width
direction Y, there is the risk that the end portion of the sheet S1
interferes with one of the regulation guides 14A, 14B to generate a
conveyance failure of the sheet S1.
[0088] Next, after the rear end (upstream end) of the sheet, which
is delivered from the conveyance roller pair 401 to the conveyance
belt 12, passes through the conveyance roller pair 401, the control
section 203 shifts the pair of regulation guides 14A, 14B from the
retract positions to the guide positions. In other words, it is
configured that the pair of regulation guides 14A, 14B arrive at
the guide positions after the sheet S loses contact with the
conveyance roller pair 401.
[0089] In addition, in the case where the conveyance roller pair
401 on the upstream side is the configuration capable of coming
into contact and separating, the conveyance roller pair 401 may be
separated before the rear end of the sheet S comes out of the
conveyance roller pair 401, after the front end of the sheet S is
delivered to the conveyance belt 12. In other words, the
contact-separation mechanism (conveyance roller pair shift section)
31 described in the above-mentioned FIGS. 7, 8A and 8B is also
applicable to the conveyance roller pair 401. The
contact-separation mechanism 31 does not only contact and separate
the conveyance roller pair, but is also capable of shifting the
conveyance roller pair to the nip position for applying the
conveyance force to the sheet, and the nip release position where
the nip pressure is weaker than in the nip position. Accordingly,
after the front end of the sheet S is delivered to the conveyance
belt 12, before the rear end of the sheet S comes out of the
conveyance roller pair 401, the conveyance roller pair 401 may be
shifted to the nip release position with the weak nip pressure.
[0090] In this case, it is configured that the pair of regulation
guides 14A, 14B arrive at the guide positions, after the conveyance
roller pair 401 is separated (shifts from the nip position to the
nip release position) by the contact-separation mechanism 31. In
addition, the nip release position is not only the state of
thoroughly completing separation as described above, and is, for
example, a state where the nip pressure is weak to the extent that
the effect is not imposed on regulation by the regulation guides
14A, 14B, and all states where the conveyance roller pair is
separated more than this state correspond to the nip release
position. In other words, the nip release position corresponds to
the state where the conveyance roller pair is separated, and the
state where the conveyance roller pair mutually comes into contact
but the nip pressure is lower than in conveying the sheet. Anyway,
in the first mode, in the state in which the sheet Si delivered to
the conveyance belt 12 exists within the predetermined region A
(FIG. 6B, within the predetermined region), the pair of regulation
guides 14A, 14B are shifted from the retract positions to the guide
positions. By this means, the correction (alignment operation) of
lateral displacement and skew of the sheet S1 is made.
[0091] In other words, in the case where the sheet exists on the
upstream side in the conveyance direction X, the regulation guides
14A, 14B are positioned in the retract positions, and the opposite
end edges of the sheet are separated from the guide faces 15A.
Then, after the sheet is further conveyed to the downstream side,
and the rear end of the sheet passes through the conveyance roller
pair 401, the regulation guides 14A, 14B shift to the guide
positions. Then, the opposite end edges of the sheet in the width
direction Y are brought into contact with the guide faces 15A. When
the sheet is struck by the guide faces 15A, while the end edges
travel along the guide faces 15A, the sheet slips between the
conveyance belt 12 and the faces, and is conveyed in the direction
parallel with the guide faces 15A. By this means, the side
registration and side skew of the sheet S1 is corrected.
[Second Mode]
[0092] The second mode will be described next with reference to
FIGS. 10A to 10C. In the second mode, as shown in FIG. 10A, first,
the sheet S is conveyed to the conveyance belt 12 in the state in
which the pair of regulation guides 14A, 14B are in the retract
positions. At this point, drive is halted in the conveyance roller
pair 402 on the downstream side from the conveyance belt 12. For
example, at timing at which the sheet detecting sensor 433 on the
upstream side of the conveyance belt 12 detects the front end of
the sheet S, the conveyance roller pair 402 is halted.
[0093] Next, as shown in FIG. 10B, in the state in which the sheet
S is conveyed by the conveyance belt 12, the front end of the sheet
S is struck by the conveyance roller pair 402 with the drive halted
on the downstream. At this point, the skew of the sheet S is
corrected, and the sheet S becomes the state shown by the solid
lines from the state shown by the dashed lines.
[0094] Then, after a lapse of a predetermined time since the front
end of the sheet S strikes the conveyance roller pair 402 i.e. when
the skew of the sheet S is corrected, as shown in FIG. 10C, the
pair of regulation guides 14A, 14B are shifted from the retract
positions to the guide positions. At this point, the lateral
displacement of the sheet S is corrected, and the sheet S becomes
the state shown by the solid lines from the state shown by the
dashed lines. In addition, the predetermined time for correcting
the skew is capable of being set as appropriate, and for example,
in this Embodiment, is 100 ms.
[0095] Subsequently, the conveyance roller pair 402 on the
downstream side is driven to convey the sheet to the downstream
side. When the front end of the sheet S arrives at the sheet
detecting sensor 435 (see FIG. 4) existing on the downstream side
of the conveyance roller pair 402, the pair of regulation guides
14A, 14B are shifted from the guide positions to the retract
positions. In other words, at the time of execution of the second
mode, after driving the conveyance roller pair 402 and starting
conveyance of the sheet to the downstream side in the conveyance
direction by the conveyance roller pair 402, the pair of regulation
guides 14A, 14B are shifted from the guide positions to the retract
positions. Then, the next sheet is received.
[Switching Between the Modes]
[0096] Herein, the above-mentioned second mode is not performed on
all sheets, and is executed on sheets with lengths (sheet lengths)
of the sheets being short in the conveyance direction and sheets
with small weighing. On the other hand, in the case of sheets with
long sheet lengths and sheets with large weighing, the first mode
is executed. Herein, the case will be described where sheet lengths
are different. In other words, the second mode is executed in the
case where the sheet length of the sheet is a first length, and the
first mode is executed in the case where the sheet length of the
sheet is a second length longer than the first length. In this
Embodiment, it is configured that the second mode is executed on
only the envelope size, and that the first mode is executed on
sheets except the envelope. A length of the sheet to switch whether
to execute the first mode or the second mode is capable of being
set as appropriate according to the apparatus.
[0097] The reason why the mode is thus switched corresponding to
the sheet size will be described with reference to FIGS. 11A and
11B. FIG. 11A illustrates a state in which a sheet S1 of the second
length with a long sheet length is conveyed onto the conveyance
belt 12, and FIG. 11B illustrates a state in which a sheet S2 of
the first length with a short sheet length is conveyed onto the
conveyance belt 12. For example, the sheet S2 is an envelope.
Further, FIGS. 11A and 11B illustrate the state in which the pair
of regulation guides 14A, 14B are in the guide positions.
[0098] In the state in which the pair of regulation guides 14A, 14B
are in the guide positions, as described above, since the pair of
regulation guides 14A, 14B are in the positions each spaced 0.5 mm
apart from the end of the sheet in the width direction, there are
slight gaps between the pair of regulation guides 14A, 14B and the
sheet. In this case, even when lengths (widths) of sheets in the
width direction are the same, the skew amount is large in the sheet
with a short sheet length. In addition, in order to make the
description easy to understand, FIGS. 11A and 11B exaggeratedly
illustrate the gaps between the sheet and the regulation guides
14A, 14B and the skew amount of the sheet.
[0099] As shown in FIG. 11A, in the case of the sheet S1 with a
long sheet length, since the pair of regulation guides 14A, 14B are
in the guide positions, it is possible to accommodate the skew
amount within a design allowable range. In contrast thereto, as
shown in FIG. 11B, in the case of the sheet S2 with a short sheet
length, even when the pair of regulation guides 14A, 14B are
positioned in the guide positions, the skew amount is large, and it
is not possible to accommodate within the design allowable range.
Therefore, in this Embodiment, in the case where the sheet length
is short, the second mode is executed, the front end of the sheet
is once struck by the conveyance roller pair 402 to correct the
skew, and subsequently, the regulation guides are shifted from the
retract positions to the guide positions to correct the lateral
displacement.
[0100] Next, one example of such mode switch control corresponding
to the sheet size will be described using FIG. 12, while referring
to FIGS. 2 to 4, 9 and so on. When a job of sheet conveyance is
started, the control section 203 acquires a sheet size from
information input to the apparatus, information beforehand
registered with the cassette for storing sheets to convey, and the
like, and determines whether or not a sheet length of sheets
conveyed to the relay conveying apparatus 400 is a predetermined
sheet length or less (S1). In addition, at the time of a start of
the job, the pair of regulation guides 14A, 14B are configured to
be positioned in the retract positions.
[0101] In the case where the sheet length is longer than the
predetermined length (No in S1), the first mode is executed. In
other words, the conveyance belt 12 and conveyance roller pair 402
are continued to be driven (S2). Then, when the rear end of the
sheet passes through the sheet detecting sensor 433 on the upstream
side of the conveyance belt 12 (Yes in S3), the pair of regulation
guides 14A, 14B are shifted from the retract positions to the guide
positions (S4).
[0102] Next, when conveyance of the sheet by the conveyance belt 12
is finished, and the sheet is delivered to the conveyance roller
pair 402 on the downstream side, it is ascertained whether or not
the sheet is a last sheet of the job (S5). When the sheet is not
the last sheet (No in S5), the flow returns to S1. When the sheet
is the last sheet (Yes in S5), the pair of regulation guides 14A,
14B are shifted from the guide positions to the retract positions,
and control is finished. In addition, in the case where the flow
returns to S1 from S5, the regulation guides 14A, 14B are already
positioned in the guide positions in S4. In addition, irrespective
of whether or not the sheet is the last sheet, the regulation
guides 14A, 14B may be shifted to the retract positions whenever a
single sheet is conveyed.
[0103] In S1, in the case where the sheet length is the
predetermined length or less, for example, in the case where the
sheet is an envelope (Yes in S1), the conveyance belt 12 is driven,
and drive of the conveyance roller pair 402 on the downstream side
is halted (S7). Then, while conveying the sheet by the conveyance
belt 12, the front end of the sheet is caused to strike the
conveyance roller pair 402, and after a lapse of a predetermined
time since the sheet strikes (Yes in S8), the pair of regulation
guides 14A, 14B are shifted from the retract positions to the guide
positions (S9). For example, the predetermined time since the front
end of the sheet strikes the conveyance roller pair 402 is
determined from the time when the front end of the sheet passes
through the sheet detecting sensor 433, the sheet length, and a
conveyance velocity of the sheet of the conveyance belt 12.
[0104] After shifting the pair of regulation guides 14A, 14B to the
guide positions, the control section 203 starts to drive the
conveyance roller pair 402 on the downstream side (S10). Then, when
the sheet detecting sensor 435 on the downstream side detects the
front end of the sheet (Yes in S11), the section 203 shifts the
pair of regulation guides 14A, 14B from the guide positions to the
retract positions, and prepares for conveyance of the next sheet
(S12). The section 203 ascertains whether or not the sheet is the
last sheet of the job (S13), and when the sheet is not the last
sheet (No in S13), returns to S1. When the sheet is the last sheet
(Yes in S13), the section 203 finishes control.
[0105] As described above, in this Embodiment, in performing the
alignment operation on the sheet, in the second mode, in the state
in which the pair of regulation guides 14A, 14B are positioned in
the retract positions, the sheet is once brought into contact with
the halted conveyance roller pair 402 on the downstream side. By
this means, it is possible to correct the skew of the sheet. Then,
subsequently, by shifting the pair of regulation guides 14A, 14B
from the retract positions to the guide positions, the lateral
displacement of the sheet is corrected. Particularly, in this
Embodiment, even in the sheet such as an envelope with a short
sheet length, it is possible to correct the skew and lateral
displacement of the sheet.
[Comparable Example]
[0106] Herein, as a comparable example, the case will be described
where the alignment operation is performed on a sheet in a
configuration shown in FIGS. 13A and 13B. In the configuration of
the comparable example, the sheet S is conveyed downward or upward
viewed in the figure, along the conveyance direction X. Then, in
order to correct skew of the sheet S, as shown in FIG. 13A, the
sheet S is conveyed by a conveyance roller pair 601 on the upstream
side, and is struck by a register roller pair 602 with drive halted
as a conveyance roller pair on the downstream side. The register
roller pair 602 and conveyance roller pair 601 on the upstream side
are disposed parallel in the direction orthogonal to the sheet
conveyance direction X.
[0107] In the case of the configuration of such a comparable
example, as shown in FIG. 13B, in causing the skewed sheet S to
strike the register roller pair 602, the skew of the sheet front
end is corrected by moving along the register roller pair 602, but
a portion nipped by the register roller pair 601 on the upstream
side is conveyed, while being skewed. Therefore, a loop is formed
obliquely with respect to the sheet S, and in the case of large
skew, there is a possibility that damage is applied to the sheet
S.
[0108] This is because the nip force for nipping the sheet of the
conveyance roller pair 601 on the upstream side is strong.
Therefore, distortion occurs between the sheet front end portion
struck by the register roller pair 602 and the portion of the sheet
nipped by the conveyance roller pair 601 on the upstream side.
Then, when the distortion is large, the damage applied to the sheet
is increased, and for example, there is the risk that a wrinkle and
the like occur. Further, in the case of the configuration of the
comparable example, since the front end of the sheet is only struck
by the register roller pair 602, although it is possible to correct
the skew of the sheet, it is not possible to correct the lateral
displacement.
[0109] In contrast thereto, in this Embodiment, the portion that
corresponds to the conveyance roller pair 601 on the upstream side
of the comparable example is the conveyance belt 12 and spheres 20,
and the nip force is weak. Therefore, when the front end of the
sheet is struck by the conveyance roller pair 402 on the downstream
side, the sheet rotates, and at this point, it is possible to make
a skew correction. Further, subsequently, also in shifting the
regulation guides 14A, 14B from the retract positions to the guide
positions, the portion of the sheet nipped by the conveyance belt
12 and spheres 20 slides in the width direction orthogonal to the
conveyance direction, and it is thereby possible to correct the
lateral displacement.
[0110] Further, in the case of this Embodiment, in both the first
mode and the second mode, it is possible to correct the skew and
lateral displacement of the sheet. Particularly, in the case where
the sheet length is long, by executing the first mode, it is
possible to suppress reductions in productivity. In other words, in
the case of the second mode, since drive of the conveyance roller
pair 402 on the downstream side is once halted, the front end of
the sheet is caused to strike the conveyance roller pair 402, and
then, the pair of regulation guides 14A, 14B are shifted to the
guide positions, as compared with the first mode, it takes a time
to perform the alignment operation. Therefore, the second mode is
executed in the case where it is not possible to sufficiently
correct skew of the sheet in the first mode such as an envelope,
and in the other cases, the first mode is executed. By this means,
while reliably making corrections of the skew and lateral
displacement of the sheet, it is possible to suppress reductions in
productivity.
<Another Embodiment>
[0111] In the above-mentioned Embodiment, the Aspect is shown where
the first mode and second mode are switched corresponding to the
sheet length, but the present invention is not limited thereto. For
example, the first mode and second mode may be switched
corresponding to a size of weighing of the sheet. In other words,
the second mode may be executed in the case where the weighing of
the sheet is first weighing, and the first mode may be executed in
the case where the weighing of the sheet is second weighing larger
than the first weighing. For example, even in the same sheet
length, the second mode may be executed on sheets (thin paper to
normal paper) with the weighing of the sheet being less than 106
g/m.sup.2, and the first mode may be executed on sheets (normal
paper to thick paper) with the weighing of the sheet being 106
g/m.sup.2 or more. In this case, it is desirable that the user is
allowed to configure the sheet weighing for each of cassettes for
storing sheets. When the user configures, the user may directly
input the weighing or may input sheet information (model number,
etc.), or a barcode reader not shown may be provided to read the
sheet information, and for example, papers ranging from thin paper
to thick paper may be sorted into ten stages for enabling the user
to select (the weighing is originally configured for each stage,
and information on the weighing is read from a thickness of the
selected sheet.). Further, a sheet thickness detecting sensor not
shown may be provided upstream of the relay conveying apparatus
400, and by detecting a thickness of the conveyed sheet, the
thickness may be converted into the weighing.
[0112] In the above-mentioned each Embodiment, the control section
203 for controlling the relay conveying apparatus 400 is provided
in the multi-stage feed apparatus 200, and the control section 140
of the image forming apparatus 100 may perform control by the
section 203. In other words, the control section may be the control
section 140. Further, the relay conveying apparatus 400 may be
provided with a control section as control sections for controlling
respective sections of the relay conveying apparatus 400.
Furthermore, the sheet conveying apparatus is not limited to the
above-mentioned relay conveying apparatus, and may be another
configuration that is a sheet conveying apparatus for conveying
sheets.
[0113] In addition, this application claims priority from Japanese
Patent Application No. 2020-112403 and Japanese Patent Application
No. 2021-094029 incorporated herein by reference.
* * * * *