U.S. patent application number 16/209770 was filed with the patent office on 2019-08-08 for sheet conveying apparatus and image forming system.
The applicant listed for this patent is TOSHIBA TEC KABUSHIKI KAISHA. Invention is credited to Yasunobu TERAO.
Application Number | 20190241384 16/209770 |
Document ID | / |
Family ID | 67476431 |
Filed Date | 2019-08-08 |
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United States Patent
Application |
20190241384 |
Kind Code |
A1 |
TERAO; Yasunobu |
August 8, 2019 |
SHEET CONVEYING APPARATUS AND IMAGE FORMING SYSTEM
Abstract
According to an embodiment, a sheet conveying apparatus includes
a roller conveying mechanism, a sheet conveying sensor, an aligning
mechanism, and a conveying controller. The conveying controller
causes the paper feed roller of the roller conveying mechanism to
be driven to convey the sheet. Furthermore, the conveying
controller causes the adjustment roller of the aligning mechanism
to be driven on the basis of a detection output of the sheet
conveying sensor such that a deviation between the course of the
sheet and a predetermined standard course is corrected.
Inventors: |
TERAO; Yasunobu; (Izunokuni
Shizuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOSHIBA TEC KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
67476431 |
Appl. No.: |
16/209770 |
Filed: |
December 4, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 7/10 20130101; B65H
9/006 20130101; B65H 2404/1441 20130101; B65H 2801/06 20130101;
B65H 2511/242 20130101; B65H 9/002 20130101; B65H 2301/3613
20130101; B65H 5/062 20130101; B65H 2404/1424 20130101; B65H 7/06
20130101 |
International
Class: |
B65H 9/00 20060101
B65H009/00; B65H 5/06 20060101 B65H005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2018 |
JP |
2018-021388 |
Claims
1. A sheet conveying apparatus, comprising: a roller conveying
mechanism that conveys a sheet by causing the sheet to come in
contact with at least one paper feed roller; a sheet conveying
sensor that detects a course of the sheet conveyed by the roller
conveying mechanism; an aligning mechanism that has at least one
adjustment roller, the adjustment roller correcting the course of
the sheet, conveying the sheet, and aligning an edge position of
the sheet; and a conveying controller configured to cause the paper
feed roller of the roller conveying mechanism to be driven to
convey the sheet, and cause the adjustment roller of the aligning
mechanism to be driven on the basis of a detection output of the
sheet conveying sensor such that a deviation between the course of
the sheet and a predetermined standard course is corrected.
2. The sheet conveying apparatus according to claim 1, wherein the
adjustment roller includes a course correcting roller that corrects
the course of the sheet conveyed by the paper feed roller and
conveys the sheet, and a resist roller that aligns the edge
position of the sheet conveyed by the course correcting roller.
3. The sheet conveying apparatus according to claim 2, further
comprising: a first contact/separate mechanism that selectively
switches a state of the course correcting roller between a first
state that the course correcting roller presses the sheet and a
second state that the course correcting roller does not press the
sheet.
4. The sheet conveying apparatus according to claim 3, wherein the
conveying controller is configured to cause the first
contact/separate mechanism to switch the state of the course
correcting roller to the first state, and cause the first
contact/separate mechanism to switch the state of the course
correcting roller to the second state after the edge of the sheet
conveyed by the course correcting roller in the first state is
nipped between the course correcting roller and the resist
roller.
5. The sheet conveying apparatus according to claim 4, wherein the
first contact/separate mechanism selectively switches between the
first state that the course correcting roller presses the sheet and
the second state that the course correcting roller does not press
the sheet on the basis of a control signal from the conveying
controller.
6. The sheet conveying apparatus according to claim 1, further
comprising: a second contact/separate mechanism that selectively
switches a state of the paper feed roller between a third state
that the paper feed roller presses the sheet and a fourth state
that the paper feed roller does not press the sheet.
7. The sheet conveying apparatus according to claim 6, wherein the
conveying controller is configured to cause the second
contact/separate mechanism to switch the state of the paper feed
roller to the third state, and cause the second contact/separate
mechanism to switch the state of the paper feed roller to the
fourth state after the edge of the sheet conveyed by the paper feed
roller in the third state arrives at the aligning mechanism.
8. The sheet conveying apparatus according to claim 7, wherein the
second contact/separate mechanism selectively switches between the
third state that the paper feed roller presses the sheet and the
fourth state that the paper feed roller does not press the sheet on
the basis of the control signal from the conveying controller.
9. An image forming system, comprising: a printer that forms an
image on a sheet; and a sheet conveying apparatus that conveys the
sheet to the printer, the sheet conveying apparatus including a
roller conveying mechanism that conveys a sheet by causing the
sheet to come in contact with at least one paper feed roller, a
sheet conveying sensor that detects a course of the sheet conveyed
by the roller conveying mechanism, an aligning mechanism that has
at least one adjustment roller, the adjustment roller correcting
the course of the sheet, conveying the sheet, and aligning an edge
position of the sheet, and a conveying controller configured to
cause the paper feed roller of the roller conveying mechanism to be
driven to convey the sheet, and cause the adjustment roller of the
aligning mechanism to be driven on the basis of a detection output
of the sheet conveying sensor such that a deviation between the
course of the sheet and a predetermined standard course is
corrected.
10. The image forming system according to claim 9, wherein the
adjustment roller includes a course correcting roller that corrects
the course of the sheet conveyed by the paper feed roller and
conveys the sheet, and a resist roller that aligns the edge
position of the sheet conveyed by the course correcting roller.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No.
2018-021388, filed on Feb. 8, 2018, the entire contents of which
are incorporated herein by reference.
FIELD
[0002] An embodiment to be described here generally relates to a
sheet conveying apparatus and an image forming system.
BACKGROUND
[0003] For example, an image forming system has a sheet conveying
apparatus such as an original document conveying apparatus, an
automatic paper feeding apparatus, and a manual feeding paper
feeding apparatus. The sheet conveying apparatus has guide fences
for feeding sheets in a predetermined conveying direction. The
sheets are aligned by the guide fences in the conveying direction.
After the sheets are aligned, the sheet conveying apparatus starts
to feed the sheets. However, if the sheets get out from the guide
fences of the sheet conveying apparatus, a sheet course (conveying
direction) may be changed. For example, if the conveying direction
of conveying rollers is tilted in latter parts of the guide fences
with respect to the conveying direction of the aligned sheets, the
conveying direction of the sheets is tilted. If conveyance
resistance of a conveying path of the sheets varies in a direction
orthogonal to the conveying direction of the sheets, the sheet
course is curved. The sheet conveying apparatus has a resist
mechanism. Even if the sheets skew during conveyance, edge
positions of the sheets are aligned by the resist mechanism.
However, skewed sheets may be twisted between the resist mechanism
and a paper feeding mechanism. Twisting of the sheets may cause
creases. Furthermore, the resist mechanism cannot correct
horizontal deviation of the sheets in the direction orthogonal to a
sheet conveying direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a cross-sectional view schematically showing a
configuration example of an image forming system according to an
embodiment.
[0005] FIG. 2 is a perspective view schematically showing a
configuration example of a manual paper feeding device of a sheet
conveying apparatus according to the embodiment.
[0006] FIG. 3 is a cross-sectional view schematically showing a
configuration example of a manual paper feeding device and
peripherals of the sheet conveying apparatus according to the
embodiment.
[0007] FIG. 4 is a perspective view schematically showing a
configuration example of a roller conveying mechanism and
peripherals of the sheet conveying apparatus according to the
embodiment.
[0008] FIG. 5A is a view schematically showing a configuration
example of main parts of a second contact/separate mechanism of the
sheet conveying apparatus according to the embodiment.
[0009] FIG. 5B is a view schematically showing a configuration
example of main parts of a second contact/separate mechanism of the
sheet conveying apparatus according to the embodiment.
[0010] FIG. 6A is a plan view showing a configuration example of a
course correcting unit of the sheet conveying apparatus according
to the embodiment.
[0011] FIG. 6B is a sectional view taken along A-A of FIG. 6A
showing course correcting rollers of the sheet conveying apparatus
according to the embodiment.
[0012] FIG. 7A is a view schematically showing a configuration
example of main parts of a first contact/separate mechanism of the
sheet conveying apparatus according to the embodiment.
[0013] FIG. 7B is a view schematically showing a configuration
example of main parts of a first contact/separate mechanism of the
sheet conveying apparatus according to the embodiment.
[0014] FIG. 8 is a block diagram showing a configuration example of
a control system of the sheet conveying apparatus according to the
embodiment.
[0015] FIG. 9 is a flowchart showing control actions of the sheet
conveying apparatus according to the embodiment.
[0016] FIG. 10 is a view for describing actions of the sheet
conveying apparatus according to the embodiment.
[0017] FIG. 11 is a view for describing actions of the sheet
conveying apparatus according to the embodiment.
[0018] FIG. 12 is a view for describing actions of the sheet
conveying apparatus according to the embodiment.
[0019] FIG. 13 is a view for describing actions of the sheet
conveying apparatus according to the embodiment.
[0020] FIG. 14 is a view for describing actions of the sheet
conveying apparatus according to the embodiment.
[0021] FIG. 15 is a view for describing actions of the sheet
conveying apparatus according to the embodiment.
DETAILED DESCRIPTION
[0022] According to an embodiment, a sheet conveying apparatus
includes a roller conveying mechanism, a sheet conveying sensor, an
aligning mechanism, and a conveying controller. The roller
conveying mechanism conveys the sheet by causing the sheet to come
in contact with at least one paper feed roller. The sheet conveying
sensor detects a course of the sheet conveyed by the roller
conveying mechanism. The aligning mechanism has at least one
adjustment roller that corrects the course of the sheet, conveys
the sheet, and aligns an edge position of the sheet. The conveying
controller causes the paper feed roller of the roller conveying
mechanism to be driven to convey the sheet. Furthermore, the
conveying controller causes the adjustment roller of the aligning
mechanism to be driven on the basis of a detection output of the
sheet conveying sensor such that a deviation between the course of
the sheet and a predetermined standard course is corrected.
[0023] Hereinafter, the sheet conveying apparatus and the image
forming system according to an embodiment will be described with
reference to the drawings. In the drawings, the same symbols denote
the same or similar parts. FIG. 1 schematically shows a
configuration example of an image forming system 100 including
sheet conveying apparatuses 1, 2, 3 according to the embodiment.
FIG. 2 schematically shows a configuration example of a manual
paper feeding device 106 of the sheet conveying apparatus 1
according to the embodiment. FIG. 3 schematically shows a
configuration example of a manual paper feeding device 106 and
peripherals. FIG. 4 schematically shows a configuration example of
a roller conveying mechanism 43 and peripherals of the sheet
conveying apparatus 1 according to the embodiment. FIG. 5A and FIG.
5B schematically show a configuration example of main parts of a
second contact/separate mechanism 44A. FIG. 6A shows a
configuration example of a course correcting unit 46 of the sheet
conveying apparatus 1 according to the embodiment. FIG. 6B is a
sectional view taken along A-A of FIG. 6A and shows course
correcting rollers 46A and 46B of the course correcting unit 46.
FIG. 7A and FIG. 7B schematically show a configuration example of
main parts of a first contact/separate mechanism 48 of the sheet
conveying apparatus 1 according to the embodiment. In the
above-mentioned drawings, the size and the shape of each member are
exaggerated or simplified for ease of view (the same applies to the
following drawings).
[0024] The image forming system 100 according to the embodiment
shown in FIG. 1 is, for example, an MFP (Multi-Function
Peripherals). The image forming system 100 may be a printer, a copy
machine, or the like. The image forming system 100 includes a
scanner 101, an ADF (Auto Document feeder) 102, a printer 103, a
paper feeding device 104, an inverting device 105, a manual paper
feeding device 106, and a controller 110. Note that, in the
following description, the configuration of the image forming
system 100 will be described on the basis of an arrangement
position of FIG. 1. The image forming system 100 of FIG. 1 is
arranged on a horizontal plane. The longitudinal direction of FIG.
1 corresponds to the vertical direction. In the image forming
system 100 of FIG. 1, a front part of the system corresponds to a
front of FIG. 1. Viewed from the direction facing to the front part
of the image forming system 100, the right side shown corresponds
to the right side of the image forming system 10. Viewed from the
direction facing to the front part of the image forming system 100,
the left side shown corresponds to the left side of the image
forming system 100. In the image forming system 100 of FIG. 1, a
back part of the system faces to the back side of FIG. 1. In the
following description, unless otherwise specified, in relation to
relative positions of the members forming the image forming system
100, terms of "front", "back", "up", "down", "left", "right", and
the like are used on the basis of the arrangement position of the
above-described image forming system 100 of FIG. 1. Accordingly,
the terms of "front", "back", "up", "down", "left", "right", and
the like in the following description may be different from the
shown positional relationship in FIG. 1.
[0025] The scanner 101 reads an original document (not shown). At
the top of the scanner 101, there is an original document plate
101a on which the original document is placed. On the original
document plate 101a, an ADF 102 is provided. The ADF 102 conveys
the original document placed on an original document placing tray
102a to an original document reading position (not shown) of the
scanner 101. After the original document is conveyed to the
original document reading position, the original document is
ejected to an original document discharging plate 102b located
downward the original document placing tray 102a.
[0026] The scanner 101 includes an illumination light source (not
shown) that illuminates the original document and an image sensor
(not shown) that photoelectrically converts reflected light from
the original document. The scanner 101 reads information of the
original document fed to the original document reading position by
the ADF 102 or the original document placed on the original
document plate 101a using the illumination light source and the
image sensor. Though not shown, at a front of the scanner 101 in
the drawing, there is provided an operation device (operation unit)
by which an operator operates actions of the image forming system
100. For example, the operation device has an operation panel
including a variety of keys or a touch panel type display.
[0027] Downward the scanner 101, a printer 103 (image forming
system body) and a paper feeding device 104 are provided in this
order. The paper feeding device 104 feeds sheets P to be imaged to
the printer 103. A direction of the sheets P moving within a paper
feeding cassette 104a described later in order to feed the sheets P
to the printer 103 by the paper feeding device 104 is referred to
as a "first paper feeding direction" in the following description.
In the example of FIG. 1, the first paper feeding direction is a
direction from the left side to the right side in the drawing. A
direction orthogonal to the first paper feeding direction in a
sheet plane of each sheet P is referred to as a first paper feeding
orthogonal direction in the following description. The paper
feeding device 104 has the paper feeding cassette 104a. The paper
feeding device 104 of FIG. 1 is provided with one paper feeding
cassette 104a as an example. However, the paper feeding device 104
may be provided with a plurality of the paper feeding cassettes
104a. The paper feeding cassette 104a is capable of holding a
variety of sizes of the sheets P. In addition, the paper feeding
cassette 104a holds the sheets P on a center basis. In other words,
the sheets P are held in the paper feeding cassette 104a such that
a center axis line in a width of each sheet in the first paper
feeding orthogonal direction is aligned at a fixed position.
Furthermore, the paper feeding device 104 has a paper feed roller
104b. The paper feed roller 104b moves the sheet P to the first
paper feeding direction in the paper feeding cassette 104a and
feeds the sheet P from the paper feeding cassette 104a to a
conveying path of the printer 103. At this time, the paper feeding
device 104 feeds the sheets P one by one separately. A method of
feeding the sheets P by the paper feeding device 104 is not
especially limited as long as the sheets P are fed by a roller
paper feeding system. Similarly, a method of separating the sheets
P is not especially limited. As the method of separating the sheets
P, an appropriate separation system such as a corner pawl system, a
separation pad system, and a separation roller system may be used,
for example. The paper feeding device 104 includes a variety of
rollers, pad members, and the like other than the paper feed roller
104b corresponding to the paper feeding system and the separation
system.
[0028] The printer 103 forms images on the sheets P on the basis of
image data of the original document read by the scanner 101 or
image data generated by a personal computer or the like. The
printer 103 is a color printer, for example, in a so-called tandem
system. The printer 103 includes an image forming device 30, a
conveying device 40, a fuser 50, and paper ejection rollers 60.
[0029] The image forming device 30 forms the images on the sheet P
by using toner having a color of yellow (Y), magenta (M), cyan (C),
or black (K). The image forming device 30 includes an exposure unit
31, imaging units 32, and a transfer unit 33.
[0030] The exposure unit 31 generates light 31a for exposing a
photoreceptor drum 32A (hereinafter referred to as exposing light
31a). The exposing light 31a forms an electrostatic latent image
corresponding to the image of the above-described each color on the
photoreceptor drum 32A included in each of four imaging units 32
described later. As the exposure unit 31, an exposure unit that
scans the photoreceptor drum 32A by using laser light from a
semiconductor laser device may be used. As the exposure unit 31, an
exposure unit including a solid scanning device such as an LED
instead of the semiconductor laser device.
[0031] Each of the four imaging units 32 includes one image
carrying body, i.e., the photoreceptor drum 32A. The respective
photoreceptor drums 32A are separated each other from the left side
to the right side and arranged in parallel in FIG. 1. Each
photoreceptor drum 32A is rotary driven clockwise as shown by using
a drive motor (not shown). Each imaging unit 32 includes a charger
32B, a developing unit 32C, and a photoreceptor cleaner 32E at each
outer periphery of the photoreceptor drum 32A. The charger 32B, the
developing unit 32C, and the photoreceptor cleaner 32E are arranged
in this order in a rotational direction of each photoreceptor drum
32A. The imaging units 32 are arranged upward the exposure unit 31.
On the four photoreceptor drums 32A, the electrostatic latent
images corresponding to the respective colors of Y, M, C, and K
from the left side to the right side are formed. Thereafter, toner
images corresponding to the electrostatic latent images are formed.
Each charger 32B, each developing unit 32C, and each photoreceptor
cleaner 32E in each imaging unit 32 have the same configuration
except that the color of the toner used for imaging is
different.
[0032] The charger 32B uniformly charges the surface of the
photoreceptor drum 32A. The exposure unit 31 irradiates the
exposing light 31a modulated on the basis of the image data onto
the charged photoreceptor drum 32A. On the photoreceptor drum 32A,
the electrostatic latent image is formed.
[0033] Each developing unit 32C includes a developing roller. The
developing unit 32C charges the toner therein. A developing bias is
applied to the developing roller. The developing unit 32C feeds the
charged toner to the surface of the photoreceptor drum 32A using
the developing roller. Once the toner is fed to the surface of the
photoreceptor drum 32A, the electrostatic latent image on the
photoreceptor drum 32A is developed with the toner. Each toner
cartridge 32F is arranged upward each developing unit 32C via each
transfer unit 33 described later. According to this embodiment,
four toner cartridges 32F feeding toner having respective colors of
Y, M, C, and K are arranged. Between each toner cartridge 32F and
each developing unit 32C, a toner dispenser (not shown) is
arranged. The toner in each toner cartridge 32F is fed to each
developing unit 32C by the toner dispenser.
[0034] Each photoreceptor cleaner 32E removes the toner not primary
transferred by a transfer unit 33 described later and remained on
the photoreceptor drum 32A from the surface of the photoreceptor
drum 32A. For example, the photoreceptor cleaner 32E has a cleaning
blade that comes in contact with the photoreceptor drum 32A. The
cleaning blade removes the toner remained on the surface of the
photoreceptor drum 32A.
[0035] The transfer unit 33 is arranged upward each photoreceptor
drum 32A facing to each photoreceptor drum 32A. The transfer unit
33 sequentially transfers each toner image formed on the surface of
each photoreceptor drum 32A to an intermediate transfer belt 33A
described later (primary transfer). By the primary transfer, the
toner image of each color (primary transferred image) is formed on
the intermediate transfer belt 33A. Furthermore, transfer unit 33
transfers the primary transferred image on the sheet P (secondary
transfer). By the secondary transfer, the toner image is formed on
the sheet P. The transfer unit 33 includes the intermediate
transfer belt 33A, a drive roller 33B, an idler roller 33C, a
primary transfer roller 33D, a secondary transfer roller 33E, and
an intermediate transfer belt cleaner 33F.
[0036] The intermediate transfer belt 33A is horizontally stretched
in the left and right directions by the drive roller 33B and a
plurality of idler rollers 33C in FIG. 1. The drive roller 33B is
rotary driven counterclockwise as shown by using a drive motor (not
shown). When the drive roller 33B is driven, the intermediate
transfer belt 33A endlessly travels counterclockwise as shown. A
linear speed of the intermediate transfer belt 33A is controlled
corresponding to a speed (process speed) of forming the toner image
on the photoreceptor drum 32A. The process speed is set in advance.
The lower surface of the intermediate transfer belt 33A shown is in
contact with the upper surface of each photoreceptor drum 32A.
[0037] Inside the intermediate transfer belt 33A, each primary
transfer roller 33D is arranged at the position facing to each
photoreceptor drum 32A. When a voltage for the primary transfer is
applied, the primary transfer roller 33D performs the primary
transfer of the toner image on each photoreceptor drum 32A to the
intermediate transfer belt 33A.
[0038] The secondary transfer roller 33E is arranged facing to the
drive roller 33B via the intermediate transfer belt 33A. The
contact position between the secondary transfer roller 33E and the
intermediate transfer belt 33A is a secondary transfer position
where the toner image is transferred (secondary transfer) from the
intermediate transfer belt 33A to the sheet P. A secondary transfer
voltage is applied to the secondary transfer roller 33E at the
secondary transfer position, when the sheet P passes between the
drive roller 33B and the secondary transfer roller 33E. When the
secondary transfer voltage is applied, the secondary transfer
roller 33E performs the secondary transfer of the toner image of
the intermediate transfer belt 33A on the sheet P.
[0039] At the position near the idler roller 33C shown at the left
end of the drawing, an intermediate transfer belt cleaner 33F is
arranged. The intermediate transfer belt cleaner 33F removes the
toner that is not secondary transferred to the sheet P and remained
on the intermediate transfer belt 33A from the intermediate
transfer belt 33A. For example, the intermediate transfer belt
cleaner 33F includes a cleaning blade being in contact with the
intermediate transfer belt 33A. The cleaning blade removes the
toner remained on the surface of the intermediate transfer belt
33A.
[0040] The conveying device 40 conveys the sheet P fed from the
paper feeding cassette 104a in the first conveying direction
(direction from the lower side to the upper side as shown) along a
first conveying path 41 of the printer 103. The first conveying
path 41 includes a plurality of conveying guide members. The first
conveying path 41 guides conveyance of the sheet P. The first
conveying path 41 is arranged between the position of the paper
feed roller 104b and the above-described secondary transfer
positon, between the secondary transfer position and a position of
the fuser 50 described later, and between the position of the fuser
50 and positions of the paper ejection rollers 60 described
later.
[0041] The conveying device 40 further includes an aligning
mechanism 42. The aligning mechanism 42 is arranged at the first
conveying path 41 between the position of the paper feed roller
104b and the secondary transfer position. The aligning mechanism 42
includes at least one adjustment roller driven by a drive motor
(not shown). The adjustment roller corrects the course of the sheet
P on the basis of detection outputs of sheet conveying sensors 47
described later. The adjustment roller aligns the edge position of
the sheet P. In a case where the aligning mechanism 42 includes a
plurality of adjustment rollers, the adjustment rollers may include
course correcting rollers (first and second course correcting
rollers 46A and 46B) and resist roller 45s. The course correcting
rollers (first and second course correcting rollers 46A and 46B)
correct the course of the sheet P on the basis of the detection
outputs of the sheet conveying sensors 47 described later. The
resist rollers 45 align the edge position of the sheet P. In a case
where the adjustment roller of the aligning mechanism 42 is
rotary-driven by the drive motor (not shown), the adjustment roller
conveys the sheet P in the first conveying direction. A linear
speed of the adjustment roller is controlled so as to synchronize
with the linear speed of the intermediate transfer belt 33A. In
other words, the linear speed of the adjustment roller is
controlled such that the toner image formed on the intermediate
transfer belt 33A and the edge of the sheet P are synchronized with
and arrive at the secondary transfer position. Note that a detailed
configuration of the aligning mechanism 42 will be described after
an overall configuration of the image forming system 100 is
described.
[0042] The fuser 50 fuses the toner image transferred to the sheet
P passing through the secondary transfer position on the sheet P.
The fuser 50 is arranged upward the secondary transfer roller 33E.
The fuser 50 includes a fusing member 51 and a pressing member 52.
The fusing member 51 and the pressing member 52 come in contact
with each other to form a nip (fusing nip). The fusing member 51
and the pressing member 52 nips the sheet P conveyed through the
first conveying path 41 at the fusing nip. The fusing member 51
heats the sheet P at the fusing nip. As the fusing member 51, a
tube-shaped endless belt or roller is used. A heating source of the
fusing member 51 is not especially limited as long as the surface
temperature of the fusing member 51 can be controlled at a fusing
temperature. The pressing member 52 presses the sheet P at the
fusing nip. As the pressing member 52, the tube-shaped endless belt
or roller is used, for example.
[0043] At least one of the fusing member 51 and the pressing member
52 is rotary-driven by a drive motor (not shown). When the drive
motor is rotated, the sheet P nipped between the fusing member 51
and the pressing member 52 is conveyed in the first conveying
direction at the fusing speed corresponding to the process
speed.
[0044] The paper ejection rollers 60 are arranged at the end of the
first conveying path 41 upward the fuser 50. Upward the fuser 50,
the first conveying path 41 is curved from the right side to the
left side as the first conveying path 41 directs from the lower
side to the upper side as shown. A paper ejection plate 103a is
arranged at the left side of the paper ejection rollers 60 as
shown, upward the image forming device 30, and downward the scanner
101.
[0045] The paper ejection rollers 60 are rotary-driven in a forward
and reverse ratable manner by a drive motor (not shown). When the
paper ejection rollers 60 rotate forward, the paper ejection
rollers 60 convey the sheet P conveyed through the first conveying
path 41 further to the paper ejection plate 103a. While the paper
ejection rollers 60 continue to rotate forward, the sheet P is
ejected on the paper ejection plate 103a. The paper ejection
rollers 60 are a pair of rollers, for example. When the paper
ejection rollers 60 rotate reverse while the sheet P enters between
the pair of paper ejection rollers 60, the sheet P is conveyed from
the left side to the right side along a route of the end of the
first conveying path 41 (switch back). In this case, the paper
ejection rollers 60 can convey the sheet P to an inverting device
105 described later.
[0046] The inverting device 105 inverses the sheet P inside out
that is passed through the fuser 50 and is switch-backed, and feeds
the sheet P again to the aligning mechanism 42. The inverting
device 105 is used for double-sided printing. The inverting device
105 is arranged at the position (right side as shown) facing to the
image forming device 30 via the first conveying path 41. The
inverting device 105 has a second conveying path 71. The second
conveying path 71 includes a plurality of conveying guide members.
The second conveying path 71 guides conveyance of the sheet P. The
second conveying path 71 is branched from the first conveying path
at the position between the fuser 50 and the paper ejection rollers
60. At the branched position of the first conveying path 41 and the
second conveying path 71, a conveying path switching unit 72 is
arranged. The conveying path switching unit 72 has a conveying path
switching member 73 that guides the sheet P from the first
conveying path 41 to the second conveying path 71 upon the reverse
rotation of the paper ejection rollers 60. The second conveying
path 71 merges with the first conveying path 41 at a merge position
between the paper feeding device 104 and the aligning mechanism
42.
[0047] The second conveying path 71 includes a plurality of
inversing conveying rollers driven by a drive motor (not shown).
Each inversing conveying roller conveys the sheet P in the second
conveying direction. The second conveying direction directs from
the paper ejection rollers 60 to the conveying path switching unit
72 via the first conveying path 41 and from the conveying path
switching unit 72 to the merge position 74 via the second conveying
path 71. The sheet P conveyed from the merge position 74 to the
first conveying path 41 is conveyed in the first conveying
direction of the first conveying path 41.
[0048] The manual paper feeding device 106 feeds the sheets P for
image formation set manually as appropriate to the printer 103. In
the following description, the direction to which the sheets P are
moved for feeding the sheets P to printer 103 by the manual paper
feeding device 106 is referred to as a second paper feeding
direction. In the example of FIG. 1, the second paper feeding
direction is the direction from the right side to the left side as
shown. In the following description, the direction orthogonal to
the second paper feeding direction in the sheet plane of the sheets
P is referred to as a second paper feeding orthogonal
direction.
[0049] The manual paper feeding device 106 has a manual paper
feeding tray 106a and manual feeding guides 106b. The manual paper
feeding tray 106a is revolvably arranged making an axis of rotation
extending in the second paper feeding orthogonal direction as the
center. In a case where the manual paper feeding device 106 is
used, the manual paper feeding tray 106a is revolved in the arrow
direction as shown (clockwise direction) and is held at the
position protruding from a side of a housing of the image forming
system 100 (position shown in FIG. 1). In a case where the manual
paper feeding device 106 is not used, the manual feeding paper
feeding tray 106a is housed in the side of the housing of the image
forming system 100 at the position overlapping with the inverting
device 105 (position shown by a long dashed double dotted line in
FIG. 1). The manual feeding guides 106b include wall-shaped members
extending in the second paper feeding direction in parallel with
and facing to the second paper feeding orthogonal direction with
respect to each other. The manual feeding guides 106b are arranged
such that each sheet P set on the manual feeding paper feeding tray
106a is nipped therebetween in the second paper feeding orthogonal
direction. The manual feeding guides 106b are slide-movable in the
second paper feeding orthogonal direction corresponding to a size
of the sheet set on the manual feeding paper feeding tray 106a. The
manual feeding guide 106b aligns each sheet P having a certain size
on a center basis on the manual feeding paper feeding tray 106a. In
other words, the sheets P are set on the manual feeding paper
feeding tray 106a by the manual feeding guide 106b such that the
center axis line of the width of each sheet P in the second paper
feeding orthogonal direction is aligned with a fixed position.
[0050] The manual paper feeding device 106 has a roller conveying
mechanism 43. The roller conveying mechanism 43 separates the
sheets P one by one from the manual feeding paper feeding tray 106a
and feeds the sheet P to the first conveying path 41. The method of
feeding the sheets P by the roller conveying mechanism 43 is not
especially limited as long as it is the roller paper feeding
method. Similarly, the method of separating the sheets P by the
roller conveying mechanism 43 is also not especially limited.
Examples of the method of separating the sheets P include an
appropriate separation method such as a separation pad system, a
separation roller system, and the like. FIG. 1 shows the separation
roller system as an example. The roller conveying mechanism 43 has
a variety of rollers, pad members, or the like corresponding to the
paper feeding system and the separation system. A detailed
configuration of the roller conveying mechanism 43 will be
described after the overall configuration of the image forming
system 100 is described.
[0051] The controller 110 controls actions of each device of the
image forming system 100 on the basis of an operation input from
the operation device (not shown). For example, the controller 110
has a CPU, a read only memory (ROM), a random access memory (RAM),
an input-output interface, an input-output control circuit, a paper
feeding/conveying control circuit, an image forming control
circuit, and a fusing control circuit. The CPU realizes a
processing function for image formation by executing a program
stored in the ROM or the RAM. The input-output control circuit of
the controller 110 controls the operation device and a display
device. As the operation device, an operation panel including a key
board, a display, and the like may be used. As the display device,
a display displaying an image, character information, and the like
may be used. The paper feeding/conveying control circuit
drive-controls the paper feeding device 104, the inverting device
105, the printer 103, the paper ejection rollers 60, and a variety
of drive motors included in the inverting device 105. The image
forming control circuit controls actions of the ADF 102, the
scanner 101, and the image forming device 30 on the basis of a
control signal from the CPU. The fusing control circuit controls
actions of the drive motor of the fuser 50 and the temperature of
the fusing member 51 on the basis of the control signal from the
CPU. A paper feeding control by the controller 110 will be
described later.
[0052] The image forming system 100 includes the sheet conveying
apparatuses 1, 2, 3 according to this embodiment. The sheet
conveying apparatus 1 according to this embodiment includes the
manual paper feeding device 106, the aligning mechanism 42, the
sheet conveying sensors 47 described later, and the controller 110.
The sheet conveying apparatus 2 according to this embodiment
includes the paper feeding device 104, the aligning mechanism 42,
the sheet conveying sensors 47, and the controller 110. The sheet
conveying apparatus 3 according to this embodiment includes the
inverting device 105, the aligning mechanism 42, the sheet
conveying sensors 47, and the controller 110. Hereinafter, a
detailed configuration of the sheet conveying apparatus 1 will be
mainly described.
[0053] As shown in FIGS. 2 to 4, the roller conveying mechanism of
the manual paper feeding device 106 has a pick-up roller 43B, a
paper feed roller 43A, and a separation roller 43C. The pick-up
roller 43B is arranged upward an edge of the manual feeding paper
feeding tray 106a. The pick-up roller 43B rotates in conjunction
with the rotation of the paper feed roller 43A described later. The
pick-up roller 43B includes a one-way clutch inside so as not to
rotate in the direction opposite to a rotational direction of the
paper feed roller 43A. The pick-up roller 43B is
contactable/separatable to an upper surface of the manual feeding
paper feeding tray 106a by a third contact/separate mechanism 44B
(see FIG. 5A and FIG. 5B) descried later. The pick-up roller 43B
takes out the sheet P (see FIG. 2) set on the manual feeding paper
feeding tray 106a. The pick-up roller 43B conveys the taken-out
sheet P in the second paper feeding direction toward the paper feed
roller 43A.
[0054] The paper feed roller 43A is arranged in line with the
pick-up roller 43B at the position toward the second paper feeding
direction with respect to the pick-up roller 43B (e.g., left side
in FIG. 3). The paper feed roller 43A is fixed to the axis of
rotation 43b. The axis of rotation 43b is revolvably fixed to a
body of the printer 103 by a bearing (not shown). The axis of
rotation 43b is connected to a paper feed roller drive motor (not
shown). The paper feed roller drive motor rotary-drives the axis of
rotation 43b. A pick-up arm 43a is connected to the axis of
rotation 43b. The pick-up arm 43a is revolvable around the center
axis line of the axis of rotation 43b. The pick-up arm 43a
rotatably supports the pick-up roller 43B around the center axis
line. As shown in FIG. 4, belt pulleys are provided to the paper
feed roller 43A and the pick-up roller 43B, respectively. A belt
43j is turned around the belt pulleys. The pick-up roller 43B
rotates in conjunction with the paper feed roller 43A with the belt
43j in the same direction as the paper feed roller 43A.
[0055] A configuration of the third contact/separate mechanism 44B
is not especially limited as long as the pick-up roller 43B is
contactable/separatable to the manual feeding paper feeding tray
106a and the sheets P on the manual feeding paper feeding tray
106a. In the example shown in FIG. 5A, the third contact/separate
mechanism 44B has a lever 44g, a tension spring 44m, and a solenoid
44k.
[0056] The lever 44g is revolvably supported by a revolving shaft
44h with respect to the body of the printer 103. The lever 44g is
extended in different directions from the revolving shaft 44h. The
lever 44g has a first end 44i and a second end 44j at edges in the
extending direction. To the first end 44i, the tension spring 44m
and the solenoid 44k are connected. The second end 44j is arranged
at a lower side of the locking unit 43i. The second end 44j is
contactable/separatable to the locking unit 43i at a lower side of
the locking unit 43i. The locking unit 43i is arranged at the
pick-up arm 43a or the pick-up roller 43B. The tension spring 44m
pulls the first end 44i. The tension direction of the tension
spring 44m is the direction where the lever 44g is revolved
counterclockwise as shown by taking the revolving shaft 44h as the
center. The end of the tension spring 44m opposite to the end
connected to the first end 44i is fixed to the body of the printer
103. The solenoid 44k switches the state of pulling the first end
44i and the state of cancelling the pulling by turning on/off
electricity. The solenoid 44k pulls the first end 44i in the
direction opposite to the pulling direction of the tension spring
44m when electricity is turned on. The solenoid 44k revolves the
lever 44g clockwise as shown by pulling the first end 44i against
the pulling of the tension spring 44m when electricity is turned
on.
[0057] FIG. 5A shows the state that the lever 44g is revolved at
the maximum clockwise as shown when electricity is turned on to the
solenoid 44k. In this case, the second end 44j is separated
downward the locking unit 43i. The pick-up arm 43a is revolved at
the maximum clockwise as shown by own weights of the pick-up arm
43a and pick-up roller 43B. The pick-up roller 43B is in contact
with the manual feeding paper feeding tray 106a or the sheet P (not
shown) on the manual feeding paper feeding tray 106a from the
above. In contrast, FIG. 5B shows the state of the solenoid 44k
when electricity is turned off. When electricity is turned off to
the solenoid 44k, the lever 44g is pulled by the tension spring
44m. The lever 44g is revolved counterclockwise as shown. FIG. 5B
shows the state that the lever 44g is revolved at the maximum
counterclockwise as shown. In this case, the second end 44j is in
contact with a lower end of the locking unit 43i downward. The
pick-up arm 43a is revolved counterclockwise as shown taking the
axis of rotation 43b as the center. The pick-up roller 43B is moved
upward the manual feeding paper feeding tray 106a or the sheets P
(not shown) on the manual feeding paper feeding tray 106a. The
pick-up roller 43B is separated from the manual feeding paper
feeding tray 106a or the sheets P (not shown) on the manual feeding
paper feeding tray 106a.
[0058] As shown in FIG. 3, the separation roller 43C is arranged
facing to the paper feed roller 43A downward the paper feed roller
43A. The separation roller 43C is contactably/separatably arranged
with respect to the paper feed roller 43A and the sheet P (not
shown) conveyed by the paper feed roller 43A. The separation roller
43C is connected to a paper feed roller drive motor (not shown) via
a torque limiter 43f, an axis of rotation 43d, and a transmission
mechanism (not shown). Note that a rotary drive direction of the
separation roller 43C is the same direction as the rotational
direction of the paper feed roller 43A. The torque limiter 43f is
arranged so as to perform a separation action that prevents the
sheets P from multiple paper feeding.
[0059] The torque limiter 43f cancels the connection to the paper
feed roller drive motor with a torque based on a frictional force
received from the paper feed roller 43A when the paper feed roller
43A comes in contact with the separation roller 43C. In this case,
the separation roller 43C rotates in conjunction with the paper
feed roller 43A in a reverse direction. The separation roller 43C
adds a certain torque load to the paper feed roller 43A. The torque
limiter 43f maintains the connection to the paper feed roller drive
motor with the torque based on a frictional force received from the
sheet P in a case where the sheet P enters between the paper feed
roller 43A and the separation roller 43C. In this case, the
separation roller 43C continues to rotate clockwise as shown. The
frictional force from the separation roller 43C acts on the sheet P
in the direction opposite to the second paper feeding direction.
The frictional force from the separation roller 43C is smaller than
a frictional force acted from the paper feed roller 43A to the
sheet P being in contact with the paper feed roller 43A. Note that
the frictional force from the separation roller 43C is greater than
a frictional force between a plurality of sheets P. Accordingly,
the separation roller 43C slips with respect to one sheet P being
in contact with the paper feed roller 43A. In a case where a
plurality of sheets P enter between the paper feed roller 43A and
the separation roller 43C, the separation roller 43C pushes back
the sheets P thereunder in the direction opposite to the second
paper feeding direction until the number of the sheets P between
the paper feed roller 43A and the separation roller 43C becomes
one. By performing the separation action, the separation roller 43C
prevents the sheets P from multiple paper feeding.
[0060] As shown in FIG. 5A and FIG. 5B, in this embodiment, the
axis of rotation 43d of the separation roller 43C is rotatably
supported by a bearing 43e fixed to a revolving arm 43h. The
revolving arm 43h is revolvably fixed to a support shaft 43g
arranged by a support shaft 43g arranged at the right side of the
separation roller 43C. The support shaft 43g extends in parallel
with the axis of rotation 43b. The support shaft 43g is fixed to
the body of the printer 103. The revolving arm 43h is revolved
around the support shaft 43g by a second contact/separate mechanism
44A described later. With this configuration, the separation roller
43C is contactably/separatably supported on the paper feed roller
43A. The above-described separation action is performed in a case
where the separation roller 43C is in contact with the paper feed
roller 43A or in a case where the separation roller 43C is in
contact with the sheet P conveyed by the paper feed roller 43A.
[0061] The second contact/separate mechanism 44A is not especially
limited as long as the separation roller 43C can be
contacted/separated with respect to the sheet P conveyed by the
paper feed roller 43A and the paper feed roller 43A. In the example
shown in FIG. 5A, the second contact/separate mechanism 44A has the
configuration substantially similar to that of the third
contact/separate mechanism 44B. The second contact/separate
mechanism 44A has a lever 44a, a tension spring 44f, and a solenoid
44e.
[0062] The lever 44a is revolvably supported by a revolving shaft
44b with respect to the body of the printer 103. The lever 44a is
extended in different directions from the revolving shaft 44b. The
lever 44d has a first end 44c and a second end 44d at edges in the
extending direction. To the first end 44c, the tension spring 44f
and the solenoid 44e are connected. The second end 44d is arranged
at a lower side of the bearing 43e. The second end 44d is
contactable/separatable to the bearing 43e at a lower side of the
bearing 43e. The tension spring 44f pulls the first end 44c. The
tension direction of the tension spring 44f is the direction where
the lever 44a is revolved clockwise as shown by taking the
revolving shaft 44b as the center. The end of the tension spring
44f opposite to the end connected to the first end 44c is fixed to
the body of the printer 103. The solenoid 44e switches the state of
pulling the first end 44c and the state of cancelling the pulling
by turning on/off electricity. The solenoid 44e pulls the first end
44c in the direction opposite to the pulling direction of the
tension spring 44f when electricity is turned on. The solenoid 44e
revolves the lever 44a counterclockwise as shown by pulling the
first end 44c against the pulling of the tension spring 44f when
electricity is turned on.
[0063] FIG. 5A shows the state that the lever 44a is revolved at
the maximum clockwise as shown when electricity is turned off to
the solenoid 44e. In this case, the lever 44a is pulled by the
tension spring 44f. The second end 44d presses the bearing 43e from
downward to upward. The revolving arm 43h is revolved at the
maximum clockwise as shown. The separation roller 43C is in contact
with the paper feed roller 43A or the sheet P (not shown) fed by
the paper feed roller 43A from the lower side. In contrast, FIG. 5B
shows the state of the solenoid 44e when electricity is turned on.
When electricity is turned on to the solenoid 44e, the lever 44a is
pulled by the solenoid 44e in the direction opposite to the pulling
direction of the tension spring 44f. The lever 44a is revolved
counterclockwise as shown. FIG. 5B shows the state that the lever
44g is revolved at the maximum counterclockwise as shown. In this
case, the second end 44d is in contact with the bearing 43e fallen
down by own weights of the revolving arm 43h and the separation
roller 43C. The revolving arm 43h is revolved counterclockwise as
shown taking the axis of rotation 43g as the center. The separation
roller 43C is moved downward the paper feed roller 43A or the sheet
P (not shown) fed by the paper feed roller 43A. The separation
roller 43C is separated from the paper feed roller 43A or the sheet
P (not shown) fed by the paper feed roller 43A.
[0064] As shown in FIG. 3, the aligning mechanism 42 has the resist
rollers 45 (adjustment roller), pre-resist detection sensor 45s,
and the course correcting unit 46. The resist rollers 45 include a
first roller 45a (adjustment roller) and a second roller 45b
(adjustment roller). The first roller 45a and the second roller 45b
come in contact with each other to form a nip. For example, as the
first roller 45a, a metal roller may be used. For example, as the
second roller 45b, a rubber roller may be used. The first roller
45a and the second roller 45b are driven by a resist roller drive
motor (not shown). The resist rollers 45 align the edge of the
sheet P. After the edge of the sheet P is aligned, the resist
rollers 45 convey the sheet P through the first conveying path 41
to the secondary transfer position.
[0065] As shown in FIG. 3, the pre-resist detection sensor 45s is
arranged at the first conveying path 41 between the resist rollers
45 and the course correcting unit 46 described later. The
pre-resist detection sensor 45s detects whether or not the edge of
the sheet P arrives at a detection position. A length from a
detection position of the pre-resist detection sensor 45s in the
first conveying direction to positions of the resist rollers 45 is
stored in the controller 110 in advance.
[0066] The course correcting unit 46 is arranged at the first
conveying path 41 between the merge position 74 and the aligning
mechanism 42. As shown in FIG. 6A and FIG. 6B, the course
correcting unit 46 has a holder 46a, flanges 46h and 46s, a motor
for parallel movement Mp, a drive plate 46m, a motor for revolving
Mr, first course correcting rollers 46A (adjustment roller and
course correcting roller), and second course correcting rollers 46B
(adjustment roller and course correcting roller).
[0067] The holder 46a holds the first course correcting rollers 46A
and the second course correcting rollers 46B described later. The
holder 46a can move the first course correcting rollers 46A and the
second course correcting rollers 46B together. As shown in FIG. 6A,
the holder 46a is moved in parallel with a conveying surface of the
sheet P by the motor for parallel movement Mp described later.
Specifically, the holder 46a is moved in a parallel movement
direction Dp along a first conveying orthogonal direction D2
orthogonal to a first conveying direction D1 in the conveying
surface of the sheet P. The holder 46a rotates and moves in a
revolving direction Dr in the conveying surface of the sheet P by
the motor for revolving Mr described later. As shown in FIG. 6B,
both ends of the holder 46a, respective side plates 46d are mounted
upright. A bearing 46b is fixed to each side plate 46d. The bearing
46b rotatably supports the first course correcting rollers 46A
around the center axis line. In each side plate 46d, a long slide
hole 46e penetrates in the direction facing to the bearing 46b next
to the bearing 46b.
[0068] Flanges 46h and 46s are arranged at a base end (upper end in
FIG. 6B) of each side plate 46d. The flanges 46h and 46s extend
from the both ends of the holder 46a in the longitudinal direction
to downward. A flange 46h has a slide hole 46i and a rack 46j. As
shown in FIG. 6A, the slide hole 46i penetrates in the thickness
direction of the flange 46h. The slide hole 46i is long in the
longitudinal direction of the holder 46a. A guide pin 46k fixed to
the body of the printer 103 is inserted into the slide hole 46i.
The rack 46j is formed in an extension direction in a side facing
to the extension direction of the flange 46h. A drive force of the
motor for parallel movement Mp is transmitted to the rack 46j via a
transmission mechanism Gp. For example, as the transmission
mechanism Gp, a gear wheel transmission mechanism having a pinion
of driving the rack 46j may be used. To the body of the printer
103, a first HP detection sensor H1 is fixed. The first HP
detection sensor H1 detects a home position (HP) of the flange 46h
in the parallel movement direction Dp. For example, as the first HP
detection sensor H1, a photo interpreter may be used.
[0069] As shown in FIG. 6A and FIG. 6B, the flange 46s has a slide
hole 46r. The slide hole 46r penetrates in the thickness direction
of the flange 46s. The slide hole 46r is long in the longitudinal
direction of the holder 46a. The drive plate 46m is revolvably
arranged in a plane parallel to the conveying surface of the sheet
P taking the rotation shaft 46n as the center. A drive pin 46q is
mounted upright to an upper surface of the drive plate 46m. The
drive pin 46q penetrates through the slide hole 46r of the flange
46s downward. As shown in FIG. 6A, the flange 46s receives the
drive force from the drive pin 46q when the drive plate 46m is
revolved around the rotation shaft 46n as the center. Corresponding
to an amount of movement of the drive pin 46q, the flange 46s is
revolved in the revolving direction Dr. At this time, the guide pin
46k is inserted into the slide hole 46i. Accordingly, the holder
46a is revolved in the revolving direction Dr as a whole around the
guide pin 46k as the center. At an outer periphery of the drive
plate 46m, a gear 46p is formed.
[0070] The drive force of the motor for revolving Mr is transmitted
to the gear 46p via the transmission mechanism Gr. For example, as
the transmission mechanism Gr, a gear wheel transmission mechanism
may be used. A second HP detection sensor H2 is fixed to the body
of the printer 103. The second HP detection sensor H2 detects the
HP of the flange 46s in the revolving direction Dr. For example, as
the second HP detection sensor H2, the photo interpreter may be
used. In this embodiment, the HP of the holder 46a is the position
when the first course correcting rollers 46A and the second course
correcting rollers 46B extend in the first conveying orthogonal
direction D2 and the first course correcting rollers 46A and the
second course correcting rollers 46B are positioned at the center
of the first conveying path 41 in the first conveying orthogonal
direction D2, as described later. Hereinafter, unless otherwise
specified, a positional relationship among respective members of
the course correcting unit 46 is described in a case where the
holder 46a is in the HP as an example.
[0071] The first course correcting rollers 46A are fixed to the
axis of rotation 46f. Both ends of the axis of rotation 46f are
inserted into the bearing 46b fixed to each side plate 46d. The
axis of rotation 46f extends in the longitudinal direction of the
holder 46a. As shown in FIG. 6B, an end of the axis of rotation 46f
(end at right side shown) penetrating to the side plate 46d having
the flange 46h is connected to the transmission mechanism Gd via a
joint 46t. The transmission mechanism Gd transmits the drive force
from a course correcting roller drive motor (not shown) to the axis
of rotation 46f. For example, as the transmission mechanism Gd, a
gear wheel transmission mechanism may be used. The joint 46t is
expandable, contractable, and revolvable along with the movement of
the axis of rotation 46f if the axis of rotation 46f moves in
association with a parallel movement and a revolving movement of
the holder 46a. A drive gear 46u is fixed to the axis of rotation
46f between the joint 46t and the side plate 46d. The drive gear
46u transmits the drive force from the course correcting roller
drive motor to the second course correcting rollers 46B.
[0072] The second course correcting rollers 46B are fixed to the
axis of rotation 46g. Both ends of the axis of rotation 46g are
inserted into the bearing 46c. The bearing 46c is, for example, a
stepped slide bearing. As shown in FIG. 7A, a small diameter part
46w of the bearing 46c is slidably fitted to the slide hole 46e in
the longitudinal direction. A large diameter part 46x of the
bearing 46c is slidably locked to an outer surface of the side
plate 46d. An idler gear 46v is fixed to the end (end at right side
shown) of the axis of rotation 46g penetrating through the side
plate 46d at the side where the flange 46h is arranged. The number
of teeth of the idler gear 46v equals to the number of teeth of the
drive gear 46u. The idler gear 46v is engaged with the drive gear
46u in a case where a positional relationship is such that the
second course correcting rollers 46B come in contact with the first
course correcting rollers 46A each other. When the idler gear 46v
is engaged with the drive gear 46u, the second course correcting
rollers 46B will be rotatable in the reverse direction of the first
course correcting rollers 46A.
[0073] The course correcting unit 46 further includes a first
contact/separate mechanism 48. The first contact/separate mechanism
48 allows the second course correcting rollers 46B to be in contact
with/be separated from the first course correcting rollers 46A. The
first contact/separate mechanism 48 is not especially limited as
long as the second course correcting rollers 46B are
contactable/separatable to the first course correcting rollers 46A.
In the example shown in FIG. 7A, the first contact/separate
mechanism 48 has a lever 48a, a tension spring 48f, and a solenoid
48e.
[0074] The lever 48a is revolvably supported by a revolving shaft
48b with respect to the holder 46a. The lever 48a is extended in
different directions from the revolving shaft 48b. The lever 48a
has a first end 48c and a second end 48d at edges in the extending
direction. To the first end 48c, the tension spring 48f and the
solenoid 48e are connected. The second end 48d is arranged at a
lower side of the large diameter part 46x of the bearing 46c. The
second end 48d is contactable/separatable to the large diameter
part 46x. The tension spring 48f pulls the first end 48c. The
tension direction of the tension spring 48f is the direction where
the lever 48a is revolved counterclockwise as shown by taking the
revolving shaft 48b as the center. The end of the tension spring
48f opposite to the end connected to the first end 48c is fixed to
a fixing unit (not shown) extending from the holder 46a. The
solenoid 48e switches the state of pulling the first end 48c and
the state of cancelling the pulling by turning on/off electricity.
The solenoid 48e pulls the first end 48c in the direction opposite
to the pulling direction of the tension spring 48f when electricity
is turned on. The solenoid 48e revolves the lever 48a
counterclockwise as shown by pulling the first end 48c against the
pulling direction of the tension spring 48f when electricity is
turned on.
[0075] FIG. 7A shows the state that electricity is turned off to
the solenoid 48e. When electricity is turned off to the solenoid
48e, the lever 48a is pulled by the tension spring 48f. The lever
48a is revolved clockwise as shown. FIG. 7A shows the state that
the lever 48a is revolved at the maximum clockwise as shown. In
this case, the second end 48d presses the large diameter part 46x
of the bearing 46c from downward to upward. At this time, as shown
in FIG. 6B, the first course correcting rollers 46A and the second
course correcting rollers 46B are in contact with each other. The
drive gear 46u and the idler gear 46v are engaged with each other
on their pitch circles. In contrast, FIG. 7B shows the state of the
solenoid 48e when electricity is turned on. When electricity is
turned on to the solenoid 48e, the lever 48a is pulled by the
solenoid 48e in the direction opposite to the pulling direction of
the tension spring 48f. The lever 48a is revolved counterclockwise
as shown. In this case, the second end 48d is in contact with the
large diameter part 46x of the bearing 46c fallen down by own
weights of the second course correcting rollers 46B. At this time,
the second course correcting rollers 46B are separated from the
first course correcting rollers 46A (see the long dashed double
dotted line in FIG. 3).
[0076] The sheet conveying sensors 47 detect the course of the
sheet P conveyed toward the resist roller 45. The course of the
sheet P is represented by an amount of skew deviation with respect
to a predetermined normal course and an amount of horizontal
deviation. The sheet P1 shown by the long dashed double dotted line
in FIG. 6A is a first size sheet P that moves in the normal course.
Similarly, the sheet P 2 is a second size sheet P that moves in the
normal course. Edges F of the sheets P1 and P2 extend in the first
conveying orthogonal direction D2. A first side end SL and a second
side end SR of the sheets P1 and P2 extend in the first conveying
direction Dl. Here, the first side end SL is the side end
positioned at a front side of the image forming system 100. The
second side end SR is the side end positioned at a back side of the
image forming system 100. The center axis lines of the sheets P1
and P2 in the first conveying orthogonal direction D2 are coincide
with the center axis line C of the normal course.
[0077] The skew deviation is represented by an angle of the edge of
the sheet P in the conveying direction tilted with respect to the
axis line extending in the first conveying orthogonal direction.
The horizontal deviation is represented by an amount of deviation
between the center axis line in the standard course and a rotation
center of the skew in the first conveying orthogonal direction D2
since the image forming system 100 conveys the sheet P on a center
basis. Note that it is not easy to determine the rotation center
during conveyance of the sheet P. In this embodiment, the amount of
horizontal deviation is detected on the basis of the position of
the side end of the sheet P after the skew deviation is corrected,
as described later.
[0078] As shown in FIG. 3, in this embodiment, as the sheet
conveying sensors 47, a skew detection sensor 47A and a horizontal
deviation detection sensor 47B are arranged in the first conveying
path 41. Furthermore, as the sheet conveying sensors 47, a skew
detection sensor 47C and a horizontal deviation detection sensor
47D are arranged in the second conveying path 71. The skew
detection sensor 47A and the horizontal deviation detection sensor
47B detect the course of the sheet P (not shown) toward the course
correcting unit 46 from the inverting device 105 through the merge
position 74. The detection action by the skew detection sensor 47A
and the horizontal deviation detection sensor 47B and the detection
action by the skew detection sensor 47C and the horizontal
deviation detection sensor 47D are similar with respect to each
other. Hereinbelow, the skew detection sensor 47A and the
horizontal deviation detection sensor 47B are taken as an example
and described.
[0079] The skew detection sensor 47A has a first skew detection
sensor 47a and a second skew detection sensor 47b. The first skew
detection sensor 47a and second skew detection sensor 47b are
arranged at a certain distance from the nips between the first
course correcting rollers 46A and the second course correcting
rollers 46B in the first conveying direction D1 at the HP of the
holder 46a. The first skew detection sensor 47a and the second skew
detection sensor 47b are arranged to leave a space with respect to
each other on the axis line extending in the first conveying
orthogonal direction D2. The first skew detection sensor 47a and
the second skew detection sensor 47b are arranged in line symmetry
with respect to each other by the center axis line C. A distance
between the first skew detection sensor 47a and the second skew
detection sensor 47b is smaller than a minimum width of the sheet P
to be fed.
[0080] If there are a plurality of width sizes of the sheets P fed
in the first conveying orthogonal direction D2, it is desirable
that the horizontal deviation detection sensor 47B have a pair of
sensors for each width size. Note that a plurality kinds of the
sheets P having similar sizes may be detected by a common pair of
sensors. In a case where the sheets P to be fed have only one
determined width size, the horizontal deviation detection sensor
47B may have only one sensor. FIG. 6A shows an example that the
horizontal deviation detection sensor 47B has first horizontal
deviation detection sensors 47c and 47e and second horizontal
deviation detection sensors 47d and 47f. The first horizontal
deviation detection sensors 47c and 47e and the second horizontal
deviation detection sensors 47d and 47f are arranged apart from the
skew detection sensor 47A in the direction opposite to the first
conveying direction D1 and on the axis line extending in the first
conveying orthogonal direction D2. The first horizontal deviation
detection sensors 47c and 47e are arranged at positions
corresponding to respective first side ends SL to the sheets P1 and
P2 moving the standard courses, respectively. The second horizontal
deviation detection sensors 47d and 47f are arranged at positions
corresponding to respective second side ends SR to the sheets P1
and P2 moving the standard courses, respectively.
[0081] The skew detection sensor 47A is not especially limited as
long as arrival of the edge F of the sheet P on sensor arrangement
positions is detectable. Examples of the skew detection sensor 47A
include a reflection type or transmission type photo sensor, a line
sensor, a CCD, and the like. The horizontal deviation detection
sensor 47B is not especially limited as long as arrival of the
first side end SL or the second side end SR of the sheet P on
sensor arrangement positions is detectable. Examples of the
horizontal deviation detection sensor 47B may include the sensors
similar to those used in the skew detection sensor 47A.
[0082] Here, a relationship between the components of the sheet
conveying apparatus 1 described above and the controller 110 will
be described. FIG. 8 is a block diagram showing a configuration
example of a control system of the sheet conveying apparatus
according to the embodiment.
[0083] As shown in FIG. 8, the controller 110 includes a system
controller 111, a conveying controller 112, and a storage device
113. The system controller 111 controls overall actions of the
image forming system 100. The system controller 111 is connected to
and communicable with a display device 114, an operation device
115, the ADF 102, the scanner 101, the image forming device 30, the
fuser 50, a conveying controller 112 described later, and the
storage device 113.
[0084] The conveying controller 112 is connected to and
communicable with the system controller 111 and the storage device
113. The conveying controller 112 controls the actions of the paper
feeding device 104, the manual paper feeding device 106, the roller
conveying mechanism 43, the inverting device 105, and the aligning
mechanism 42 described above on the basis of a control signal from
the system controller 111. The conveying controller 112 is further
connected to and communicable with the skew detection sensor 47A,
the horizontal deviation detection sensor 47B, a first HP detection
sensor H1, a second HP detection sensor H2, the pre-resist
detection sensor 45s, the motor for parallel movement Mp, the motor
for revolving Mr, the first contact/separate mechanism 48, the
second contact/separate mechanism 44A, the third contact/separate
mechanism 44B, the course correcting roller drive motor M46, the
resist roller drive motor M45, and a paper feed roller drive motor
M43. Here, the course correcting roller drive motor M46 drives the
first course correcting rollers 46A. The resist roller drive motor
M45 drives the resist roller 45. The paper feed roller drive motor
M43 supplies a drive force to the roller conveying mechanism 43.
The paper feed roller drive motor M43 drives at least the paper
feed roller 43A.
[0085] The storage device 113 stores control data needed for the
control performed by the system controller 111 and the conveying
controller 112. The storage device 113 includes a ROM, a RAM, other
storage medium, or the like.
[0086] Next, the actions of the image forming system 100 will be
described mainly about the actions of the sheet conveying apparatus
1. FIG. 9 is a flowchart showing the actions of the sheet conveying
apparatus according to the embodiment. FIGS. 10 to 13 are views for
describing the actions of the sheet conveying apparatus according
to the embodiment.
[0087] The image forming system 100 according to the embodiment
shown in FIG. 1 performs image formation on the sheets P by an
operation of an operator on the operation device or operation
commands from an external device connected to the image forming
system 100. When the sheet P is conveyed from the sheet conveying
apparatuses 1, 2, and 3, the toner image is formed on the sheet P
by a well-known electrophotographic process performed by the image
forming device 30. The toner image of the sheet P is fused to the
sheet P by the fuser 50. The sheet P to which the toner image is
fused is ejected to the paper ejection plate 103a by the paper
ejection rollers 60 or is conveyed to the inverting device 105 for
performing the image formation on both sides of the sheet P
(double-sided printing). Hereinafter, a conveying action of the
sheets P performed by the sheet conveying apparatus 1 will be
described in detail.
[0088] For example, when a start operation of the image formation
is done from the operation device 115, the system controller 111
transmits a control signal of starting paper feeding to the
conveying controller 112. For example, the paper feeding from the
manual paper feeding device 106 is selected by an operation input
from the operation device 115. In this case, the conveying
controller 112 feeds and conveys the sheets P to the printer 103 by
executing processes of ACT1 to ACT12 shown in FIG. 9. In the
following description, the width size of the sheet P is the same as
that of the sheet P1 described above. Before the paper feeding is
started by the control of the conveying controller 112, electricity
is turned off to the solenoid 48e of the first contact/separate
mechanism 48, the solenoid 44e of the second contact/separate
mechanism 44A, and the solenoid 44k of the third contact/separate
mechanism 44B. The holder 46a of the course correcting unit 46 is
positioned at the HP.
[0089] In ACT1, the roller conveying mechanism 43 feeds the sheets
P. By the conveying controller 112, electricity is turned on to the
solenoid 44k of the third contact/separate mechanism 44B. As shown
in FIG. 3, the pick-up roller 43B comes in contact with the upper
surface of the sheet P set on the manual paper feeding device 106.
The separation roller 43C is in contact with the paper feed roller
43A. The conveying controller 112 rotates the paper feed roller
drive motor M43. The paper feed roller 43A and the pick-up roller
43B rotates clockwise as shown. The separation roller 43C rotates
counterclockwise in FIG. 3 by the drive force from the paper feed
roller 43A. The sheet P is taken out from the manual feeding paper
feeding tray 106a by the pick-up roller 43B. The sheet P is
conveyed in the second paper feeding direction by the pick-up
roller 43B. The edge of the sheet P arrives at the nip between the
paper feed roller 43A and the separation roller 43C. Even if a
plurality of sheets P are conveyed from the manual feeding paper
feeding tray 106a, the above-described separation action is
performed by the separation roller 43C. Accordingly, one sheet P
enters into the nip between the paper feed roller 43A and the
separation roller 43C. The sheet P is conveyed in the first
conveying path 41 that directs to the course correcting unit 46 by
receiving the drive force from the paper feed roller 43A. In this
manner, the process of ACT1 is ended.
[0090] After the process of ACT1, a process of ACT2 is performed.
In ACT2, the skew detection sensor 47A detects skew of the sheet P.
For example, after the process of ACT1, when the sheet P moves in
the standard course, as schematically shown as the P1 in FIG. 10, a
nip N45 of the paper feed roller 43A and the separation roller 43C,
a nip N46 of the first course correcting rollers 46A and the second
course correcting rollers 46B, and the edge F are all parallel to
the axis line extending in the first conveying orthogonal direction
D2. However, due to a various reasons, the sheet P may not move in
the standard course. For example, as shown in FIG. 11, the sheet P
may move by tilting at angle .theta. with respect to the center
axis line C of the standard course. The edge F of the sheet P is
skewed with respect to the nip N45 by the angle .theta..
Furthermore, the course of the sheet P1 is horizontally deviated
with respect to the center axis line C.
[0091] The skew of the sheet P is detected by the first skew
detection sensor 47a and the second skew detection sensor 47b of
the skew detection sensor 47A. In the example shown in FIG. 11, the
edge F of the sheet P passes through the detection position of the
second skew detection sensor 47b at time t1 and then passes through
the detection position of the first skew detection sensor 47a at
time t2. The second skew detection sensor 47b and the first skew
detection sensor 47a transmit detection signals that detect the
passage of the edge F to the conveying controller 112 at respective
detection times. The conveying controller 112 receives the
detection signals from both of the second skew detection sensor 47b
and the first skew detection sensor 47a and then calculates the
angle .theta. that represents the skew deviation of the edge F on
the basis of a time difference between time t2 and time t1, the
linear speed of the paper feed roller 43A. In this manner, the
process of ACT2 is ended.
[0092] After the process of ACT2, a process of ACT3 is performed.
In ACT3, corresponding to the skew of the sheet P, the first course
correcting rollers 46A and the second course correcting rollers 46B
revolve. The conveying controller 112 revolves the holder 46a such
that the nip N46 will be in parallel with the edge F. Specifically,
the conveying controller 112 calculates an amount of rotation of
the motor for revolving Mr with respect to the angle .theta.. The
conveying controller 112 rotates the motor for revolving Mr on the
basis of the amount of rotation calculated. The holder 46a holding
the first course correcting rollers 46A and the second course
correcting rollers 46B is revolved by the angle .theta. taking the
guide pin 46k as the revolving center. In this manner, as shown in
FIG. 11, the nip N46 is arranged in parallel with the edge F. In
this manner, the process of ACT3 is ended.
[0093] After the process of ACT3, a process of ACT4 is performed.
In ACT4, the edge F of the sheet P enters to the nip N46 of the
first course correcting rollers 46A and the second course
correcting rollers 46B (see FIG. 12). In this embodiment, the
conveying controller 112 calculates in advance an estimated arrival
time t3 that the edge F arrives at the nip N46 with certainty on
the basis of the time t2 when the edge F arrives at the first skew
detection sensor 47a and the linear speed of the paper feed roller
43A until the sheet P arrives at the nip N46. For example, as the
distance between the roller conveying mechanism 43 and the course
correcting unit 46 is long, revolving the holder 46a is ended with
certainty until the estimated arrival time t3. In this case, the
conveying controller 112 may rotate the course correcting roller
drive motor M46 at the same time as the start of the paper feeding
in ACT1. For example, as the distance between the roller conveying
mechanism 43 and the course correcting unit 46 is short, revolving
the holder 46a may not be ended with certainty until the estimated
arrival time t3. In this case, the conveying controller 112 may
rotate the course correcting roller drive motor M46 after revolving
the holder 46a is ended. For example, the conveying controller 112
may rotate the course correcting roller drive motor M46 after the
end of revolving the holder 46a and after the estimated arrival
time t3. In this case, the position of the edge F of the sheet P is
aligned by the first course correcting rollers 46A and the second
course correcting rollers 46B where their rotation is stopped.
[0094] In a case where the course correcting roller drive motor M46
is rotated, the sheet P arrived at the nip N46 enters to the nip
N46 by the rotations of the first course correcting rollers 46A and
the second course correcting rollers 46B. The sheet P is nipped
with the first course correcting rollers 46A and the second course
correcting rollers 46B. The sheet P is conveyed in the first
conveying direction D1 by the rotations of the first course
correcting rollers 46A and the second course correcting rollers
46B. In this manner, the process of ACT4 is ended.
[0095] After the process of ACT4, a process of ACT5 is performed.
In ACT5, the second contact/separate mechanism 44A cancels the
pressing of the paper feed roller 43A to the sheet P. Specifically,
after the estimated arrival time t3 and in a case where the course
correcting unit 46 is driven, the conveying controller 112 controls
such that electricity is turned off to the solenoid 44e of the
second contact/separate mechanism 44A and the solenoid 44k of the
third contact/separate mechanism 44B. When electricity is turned
off to the solenoid 44e, the separation roller 43C is separated
downward from the sheet P conveyed by the paper feed roller 43A.
The second contact/separate mechanism 44A gives the state (fourth
state) that the sheet P is not pressed by the paper feed roller
43A. In FIG. 12, the paper feed roller 43A is shown by a long
dashed double dotted line, which schematically shows that the paper
feed roller 43A becomes in the fourth state. In other words, the
second contact/separate mechanism 44A cancels the state (third
state) that the sheet P is pressed by the paper feed roller 43A.
When electricity is turned off to the solenoid 44k, the separation
roller 43B is separated upward from the surface of the sheet P. The
state that the pick-up roller 43B presses the sheet P is canceled.
In this manner, the sheet P is conveyed by the rotations of the
first course correcting rollers 46A and the second course
correcting rollers 46B. At this time, a conveyance load of the
sheet P caused by the paper feed roller 43A, the pick-up roller
43B, and the separation roller 43C is canceled. In particular,
since the sheet P is separated from the separation roller 43C, the
sheet P will not receive the drive force that returns the sheet P
in the direction opposite to the first conveying direction D1 and
the reverse direction due to the rotation of the separation roller
43C. Furthermore, the sheet P will not be restricted by the paper
feed roller 43A, the pick-up roller 43B, and the separation roller
43C that do not press the sheet P. The sheet P is conveyed in the
direction orthogonal to the nip N46. In this manner, the process of
ACT5 is ended.
[0096] After the process of ACT5, a process of ACT6 is performed.
In ACT6, the first course correcting rollers 46A and the second
course correcting rollers 46B are revolved together with the holder
46a, whereby the skew of the sheet P is corrected. Specifically,
the conveying controller 112 drives the motor for revolving Mr and
returns the holder 46a to the HP. The nip N46 is revolved as shown
by an arrow R46 in FIG. 12. The revolving angle of the nip N46 is
-.theta.. At this time, the sheet P is not pressed by the paper
feed roller 43A, the pick-up roller 43B, and the separation roller
43C. The sheet P is revolved similar to the nip N46 as shown by
arrow RP. The sheet P is not restricted except by the first course
correcting rollers 46A and the second course correcting rollers
46B. The sheet P is smoothly revolved. No warp, corrugation, or the
like is generated on the sheet P. As shown in FIG. 13, the edge F
of the sheet P' is in parallel with the nip N45. The skew of the
sheet P is corrected. At this time, the position of the edge F in
the first conveying direction D1 is calculated from the time
required to revolve and an amount of conveyance by the first course
correcting rollers 46A and the second course correcting rollers 46B
within the time. In this manner, the process of ACT6 is ended.
[0097] After the process of ACT6 is ended, a process of ACT7 is
performed. In ACT7, the first course correcting rollers 46A and the
second course correcting rollers 46B move in parallel together with
the movement holder 46a, whereby the horizontal deviation of the
sheet P is corrected. Specifically, the conveying controller 112
monitors the detection signals of the first horizontal deviation
detection sensor 47c and the second horizontal deviation detection
sensor 47d. For example, in the example shown in FIG. 12, the first
horizontal deviation detection sensor 47c detects that the sheet P
(P') is not present at the detection position of the first
horizontal deviation detection sensor 47c. The second horizontal
deviation detection sensor 47d detects that the sheet P (P') is
present at the detection position of the second horizontal
deviation detection sensor 47d. On the basis of the combination of
the detection signals, the conveying controller 112 moves in
parallel the holder 46a in the first conveying orthogonal direction
D2 closer to the first horizontal deviation detection sensor 47c as
shown by the arrow S46. Specifically, the conveying controller 112
drives the motor for parallel movement Mp such that the holder 46a
moves in the direction shown by the arrow S46. In a case where the
first horizontal deviation detection sensor 47c and the second
horizontal deviation detection sensor 47d detect the first side end
SL and the second side end SR of the sheet P, respectively, the
conveying controller 112 stops driving of the motor for parallel
movement Mp. By the parallel movement of the holder 46a, the sheet
P (P') is moved in parallel in the direction shown by the arrow DP.
The arrow DP is a skew direction closer to the center axis line C
of the center axis line CP as the edge F of the sheet P (P') moves
in the first conveying direction D1. At this time, the sheet P is
not pressed by the paper feed roller 43A, the pick-up roller 43B,
and the separation roller 43C. The sheet P is moves in parallel
smoothly similar to the revolvement in ACT6. No warp, corrugation,
or the like is generated on the sheet P. In this manner, the
horizontal deviation of the sheet P is corrected shown as the sheet
P'' in FIG. 14. In this manner, the process of ACT7 is ended.
[0098] For example, the width size of the sheet P is different from
an arrangement distance between the first horizontal deviation
detection sensor 47c and the second horizontal deviation detection
sensor 47d. In this case, in ACT7, the conveying controller 112
moves in parallel the sheet P such that the first horizontal
deviation detection sensor 47c detects the first side end SL of the
sheet P or the second horizontal deviation detection sensor 47d
detects the second side end SR of the sheet P. Thereafter, on the
basis of the predetermined width size of the sheet P, the sheet P
is moved in parallel for a moved distance where the center axis
line CP is matched with the center axis line C.
[0099] After the process of ACT7 is ended, a process of ACT8 is
performed. In ACT8, it is determined whether or not the edge F of
the sheet P arrives at the resist roller 45. Specifically, the
conveying controller 112 monitors the detection signal of the
pre-resist detection sensor 45s. When the detection signal of the
pre-resist detection sensor 45s notifies the conveying controller
112 of the arrival of the edge F at a detection position of the
first roller 45a, the conveying controller 112 determines that the
edge F of the sheet P arrives at the nip N45 of the resist rollers
45 after a predetermined time from a detection time. The
predetermined time that is different depending on the conveying
speed of the sheet P is stored in the storage device 113 in
advance. In a case where it is determined that the edge F of the
sheet arrives at the nip N45 of the resist rollers 45 (ACT8: YES),
the process in ACT9 is performed. In a case where it is determined
that the edge F of the sheet does not arrive at the nip N45 of the
resist rollers 45 (ACT8: NO), the process in ACT8 is again
performed.
[0100] After the process of ACT8 is ended, a process of ACT9 is
performed. In ACT9, the second contact/separate mechanism 44A
causes the paper feed roller 43A to press the sheet P.
Specifically, by the conveying controller 112, electricity is
turned off to the solenoid 44e. Since the tension spring 44f of the
second contact/separate mechanism 44A revolves the lever 44a, the
revolving arm 43h is revolved. The separation roller 43C is pressed
toward the paper feed roller 43A by a tension force of the tension
spring 44f. The paper feed roller 43A presses the sheet P toward
the separation roller 43C. The sheet P is ready to be conveyed in
the first conveying direction D1 by the course correcting unit 46
and the paper feed roller 43A. The resist rollers 45 are stopped.
The edge F of the sheet P is pressed toward the nip N45 of the
resist rollers 45. In this manner, the process of ACT9 is
ended.
[0101] After the process of ACT9 is ended, a process of ACT10 is
performed. In ACT10, the first contact/separate mechanism 48
cancels the pressing of the sheet P to the first course correcting
rollers 46A and the second course correcting rollers 46B.
Specifically, by the conveying controller 112, electricity is
turned on to the solenoid 48e of the first contact/separate
mechanism 48. When electricity is turned on to the solenoid 48e,
the second course correcting rollers 46B are separated from the
first course correcting rollers 46A by own weights. The first
contact/separate mechanism 48 gives the state (second state) that
the sheet P is not pressed by the first course correcting rollers
46A and the second course correcting rollers 46B. Accordingly, the
state (first state) that the sheet P is pressed by the first course
correcting rollers 46A and the second course correcting rollers 46B
is canceled. The sheet P is conveyed by the paper feed roller 43A
in the first conveying direction Dl. Depending on the amount of
conveyance, slack is generated between the resist rollers 45 and
the paper feed roller 43A. In this manner, the process of ACT10 is
ended.
[0102] After the process of ACT10 is ended, a process of ACT11 is
performed. In ACT11, the conveying controller 112 monitors whether
or not a resist ON signal for starting driving of the resist
rollers 45 is transmitted from the system controller 111. The
system controller 111 generates the resist ON signal depending on a
state of progress in an imaging process that is performed in
parallel with the above-described paper feeding conveying action.
The resist ON signal is generated at timing when the toner image on
the intermediate transfer belt 33A arrives at the secondary
transfer position and an effective image area of the sheet P can be
arrived at the secondary transfer position. In a case where the
resist ON signal is generated (ACT11: YES), a process of ACT12 is
performed. In a case where the resist ON signal is not generated
(ACT11: NO), the process of ACT11 is performed again.
[0103] After the process of ACT11 is ended, a process of ACT12 is
performed. In ACT11, it starts to convey the sheet P toward the
secondary transfer position. Specifically, the conveying controller
112 drives the resist roller drive motor M45 and rotates the resist
roller 45. The sheet P receives the drive forces of the resist
rollers 45 and the paper feed roller 43A and is conveyed through
the first conveying path 41 toward the secondary transfer position.
At this time, the course of the sheet P coincides with the standard
course. In this manner, the process of ACT11 is ended.
[0104] When the sheet P moving in the first conveying path 41
arrives at the secondary transfer position, the toner image is
transferred from the intermediate transfer belt 33A. When the sheet
P arrives at the fuser 50, the toner image is fused on the sheet P
by the fuser 50. The sheet P passed through the fuser 50 is ejected
to the paper ejection plate 103a by the paper ejection rollers 60
or is conveyed by the inverting device 105 for the double-sided
printing. In this manner, the image forming system 100 forms the
image on the sheet P.
[0105] As described above, the sheet conveying apparatus 1
according to this embodiment can inhibit the skew of the edge F of
the sheet P fed to the printer 103 and the horizontal deviation of
the sheet P in the first conveying orthogonal direction D2. Thus,
the image forming system 100 prevents the image formed on the sheet
P from skewing or horizontally deviated to the sheet P. According
to sheet conveying apparatus 1 of this embodiment, if at least one
of the skew and the horizontal deviation occurs on the conveying
path where the sheet P is fed from the manual feeding paper feeding
tray 106a to the course correcting unit 46, the course of the sheet
P can coincides with the standard course until the sheet P arrives
at the resist roller 45. For example, even if the manual feeding
guide 106b is loose or the operator roughly sets the sheets P on
the manual feeding paper feeding tray 106a, the course of each
sheet P can coincide with the standard course.
[0106] In the above-described embodiments, the sheet conveying
apparatus 1 is described. However, the sheet conveying apparatuses
2 and 3 also have the course correcting unit 46 and it is thus
possible to inhibit the skew of the edge of the sheet and the
horizontal deviation of the sheet in the direction orthogonal to
the conveying direction similar to the sheet conveying apparatus
1.
[0107] As described above, according to at least one embodiment,
there can be provided a sheet conveying apparatus and an image
forming system that can inhibit the skew of the edge of the sheet
and the horizontal deviation of the sheet in the direction
orthogonal to the conveying direction.
[0108] Note that, in the above-described embodiments, the sheet
conveying apparatus used for the manual paper feeding device 106,
the paper feeding device 104, and the inverting device 105 is
described. However, the sheet conveying apparatus may be used for
conveying the original document as the sheet. For example, the
sheet conveying apparatus may be used for the ADF 102. In this
case, a resist member in a last stage of the aligning mechanism may
be a plate-shaped stopper.
[0109] In the above-described embodiments, the sheet conveying
apparatus 1 having the first contact/separate mechanism 48, the
second contact/separate mechanism 44A, and the third
contact/separate mechanism 44B is described. However, depending on
the arrangement distance among the resist roller 45, the course
correcting unit 46, and the roller conveying mechanism 43, the
sheet conveying apparatus 1 does not have at least one of the first
contact/separate mechanism 48, the second contact/separate
mechanism 44A, and third contact/separate mechanism 44B, the course
may be appropriately corrected by the course correcting unit 46. In
this case, the sheet conveying apparatus 1 may not have at least
one of the first contact/separate mechanism 48, the second
contact/separate mechanism 44A, and the third contact/separate
mechanism 44B.
[0110] The above-descried embodiments illustrate that the second
contact/separate mechanism 44A moves the separation roller 43C such
that the paper feed roller 43A does not press the sheet P. However,
the separation roller 43C may be fixed and the paper feed roller
43A may be moved to perform the contact/separate action.
Furthermore, both the separation roller 43C and the paper feed
roller 43A may be moved to perform the contact/separate action.
[0111] The above-descried embodiments illustrate that the roller
conveying mechanism 43 has the pick-up roller 43B and the
separation roller 43C. However, the paper feeding method and the
separation method are not limited thereto. For example, in a case
where a separation pad method is used, the separation pad is
separated from the paper feed roller. Then, it is possible to
perform the contact/separate action similar to the second
contact/separate mechanism 44A.
[0112] The above-descried embodiments illustrate that the aligning
mechanism 42 has the resist rollers 45 and the course correcting
unit 46. However, if it is possible to form paper slack between the
course correcting unit 46 and the roller conveying mechanism 43
while the resist ON signal is waited, the aligning mechanism 42 may
not have the resist roller 45. In this case, the following
modifications may be added to the above-described embodiments. For
example, after the process of ACT4 in FIG. 9, the course correcting
roller drive motor M46 is stopped and the processes of ACTS to 7
are performed. Thereafter, the process of ACT8 is omitted. After
the process of ACT9 is performed, the process of ACT10 is omitted,
and the process of ACT11 is performed. Furthermore, in ACT12, it
starts to drive the first course correcting rollers 46A and the
second course correcting rollers 46B.
[0113] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the inventions. Indeed, the novel
embodiments described herein may be embodied in a variety of other
forms; furthermore, various omissions, substitutions and changes in
the form of the embodiments described herein may be made without
departing from the spirit of the inventions. The accompanying
claims and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
inventions.
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