U.S. patent application number 11/615339 was filed with the patent office on 2008-06-26 for sheet processing apparatus.
This patent application is currently assigned to TOSHIBA TEC KABUSHIKI KAISHA. Invention is credited to Yasunobu Terao.
Application Number | 20080150228 11/615339 |
Document ID | / |
Family ID | 39541720 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080150228 |
Kind Code |
A1 |
Terao; Yasunobu |
June 26, 2008 |
SHEET PROCESSING APPARATUS
Abstract
A sheet processing apparatus according to this invention is for
sorting and discharging papers supplied from an image forming
apparatus, and includes an alignment device configured to shift the
papers transported from the image forming apparatus into a
direction orthogonal to the direction of the transport and thus
align the papers in the direction of width, and a paper discharge
unit configured to guide the aligned and shifted papers to a
discharge port and discharge the shifted papers from the discharge
port and at different angles from each other.
Inventors: |
Terao; Yasunobu;
(Izunokuni-shi, JP) |
Correspondence
Address: |
AMIN, TUROCY & CALVIN, LLP
1900 EAST 9TH STREET, NATIONAL CITY CENTER, 24TH FLOOR,
CLEVELAND
OH
44114
US
|
Assignee: |
TOSHIBA TEC KABUSHIKI
KAISHA
Tokyo
JP
|
Family ID: |
39541720 |
Appl. No.: |
11/615339 |
Filed: |
December 22, 2006 |
Current U.S.
Class: |
271/286 |
Current CPC
Class: |
B65H 2404/725 20130101;
B65H 2301/4213 20130101; B65H 2801/27 20130101; B65H 2405/11151
20130101; B65H 2301/4219 20130101; B65H 2801/06 20130101; B65H
2301/4211 20130101; B65H 33/08 20130101; B65H 2801/31 20130101 |
Class at
Publication: |
271/286 |
International
Class: |
B65H 29/00 20060101
B65H029/00 |
Claims
1. A sheet processing apparatus capable of sorting and discharging
papers supplied from an image forming apparatus, comprising: an
alignment device configured to shift the papers sequentially
transported from the image forming apparatus into a first direction
orthogonal to the direction of the transport and a second direction
opposite to the first direction, and thus align the papers in the
direction of width; a paper discharge unit configured to guide the
papers aligned by the alignment device to a discharge port and
discharge the papers shifted to the first direction and the second
direction, from the discharge port and at different angles from
each other; and a paper discharge tray configured to receive the
papers discharged from the discharge port.
2. The sheet processing apparatus according to claim 1, wherein the
paper discharge unit discharges the papers shifted to the first
direction and the second direction, into angular directions
dispersing from each other.
3. The sheet processing apparatus according to claim 1, wherein the
paper discharge unit discharges the papers shifted to the first
direction and the second direction, into angular directions
crossing each other.
4. The sheet processing apparatus according to claim 1, wherein the
paper discharge unit has a first roller member that guides the
papers aligned by the alignment device to the discharge port, and
plural discharge rollers arranged on a shaft orthogonal to the
direction of discharge of the papers, the plural discharge rollers
including a first discharge roller that supports a central part of
the papers to be discharged and second and third discharge rollers
that support both side of the papers to be discharged, and the
papers guided by the first roller member are transported to the
discharge port by rotations of the first, second and third
discharge rollers, and in the course of the transport, the rotation
speeds of the second and third discharge rollers are relatively
switched with reference to the rotation speed of the first
discharge roller.
5. The sheet processing apparatus according to claim 4, wherein the
paper discharge unit alternately switches the rotation speeds of
the second and third discharge rollers every time the paper shifted
to the first direction and the paper shifted to the second
direction are discharged.
6. The sheet processing apparatus according to claim 4, wherein the
paper discharge unit stops the rotation of the first, second and
third discharge rollers immediately before the papers shifted to
the first direction and the second direction are discharged to the
paper discharge tray.
7. The sheet processing apparatus according to claim 1, wherein the
paper discharge tray is arranged at a predetermined inclination
angle, and is provided with a slip preventing member for reducing
slip of the papers discharged at a predetermined angle to the paper
discharge tray because of the inclination angle.
8. The sheet processing apparatus according to claim 7, wherein the
slip preventing member includes a pin that can protrude on a paper
stacking surface of the paper discharge tray when sorting and
discharging the papers.
9. The sheet processing apparatus according to claim 7, wherein the
slip preventing member includes a pin that can protrude from the
discharge port side to a paper stacking surface of the paper
discharge tray when sorting and discharging the papers.
10. The sheet processing apparatus according to claim 1, wherein
the paper discharge tray has an angular-adjustable paper stacking
surface, and the paper stacking surface becomes closer to a flat
surface when sorting and discharging the papers.
11. The sheet processing apparatus according to claim 1, wherein
the alignment devices includes a pair of lateral alignment plates
that align the papers in the direction of width, and alternately
shifts the papers sequentially transported from the image forming
apparatus into the first direction and the second direction by
moving the pair of lateral alignment plates.
12. A sheet processing apparatus capable of sorting and discharging
papers supplied from an image forming apparatus, comprising: an
alignment device including a pair of alignment plates that align
the papers in the direction of width, and capable of shifting the
papers sequentially transported from the image forming apparatus
into a first direction orthogonal to the direction of the transport
and a second direction opposite to the first direction; a paper
discharge unit including a first discharge roller that is arranged
near a paper discharge port and that supports a central part of the
papers to be discharged, and second and third discharge rollers
that support both sides of the papers to be discharged; a paper
discharge tray configured to receive the papers discharged from the
discharge port; a first control unit configured to shift the pair
of alignment plates to the first direction and the second
direction; and a second control unit configured to control rotation
states of the first, second and third discharge rollers, transport
the shifted papers to the discharge port, relatively switch the
rotation speeds of the second and third discharge rollers with
reference to the rotation speed of the first discharge roller, and
thus control discharge angle of the papers.
13. The sheet processing apparatus according to claim 12, wherein
the second control unit rotates the first, second and third
discharge rollers to transport the papers shifted to the first
direction and the second direction, to the discharge port, and
relatively switches the rotation speeds of the second and third
discharge rollers in the course of the transport, thus controlling
the discharge angle of the papers.
14. The sheet processing apparatus according to claim 12, wherein
the paper discharge unit alternately switches the rotation speeds
of the second and third discharge rollers every time the paper
shifted to the first direction and the paper shifted to the second
direction are discharged.
15. The sheet processing apparatus according to claim 12, wherein
the paper discharge unit stops the rotation of the first, second
and third discharge rollers immediately before the papers shifted
to the first direction and second direction are discharged to the
paper discharge tray.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a sheet processing apparatus that
performs post-processing of sheets discharged from an image forming
apparatus such as a copy machine, printer, or multifunction
peripheral.
[0003] 2. Description of the Related Art
[0004] Recently, for some image forming apparatuses, a sheet
post-processing apparatus is provided next to the paper discharge
unit in the body of the image forming apparatus in order to perform
post-processing such as sorting sheets after images are formed
thereon, or performing stapling processing to the sheets.
[0005] JP-A-5-139610 (laid open on Jun. 8, 1993) describes a sheet
post-processing apparatus that can carry out sorting processing of
sheets. In this example, it is described that an aligning unit that
aligns a sheet pack is provided and the alignment position of the
sheet pack is shifted, thereby discharging each sheet of the sheet
pack in an offsetting manner.
[0006] Also, JP-A-5-278921 (laid open on Oct. 26, 1993) describes a
paper discharge tray mounted on an image forming apparatus. The
paper discharge tray in this example can freely open and close in a
sectorial form.
[0007] Moreover, JP-A-2001-2314 (laid open on Jan. 9, 2001)
describes a sheet processing apparatus that sorts sheets into
plural tray groups. In this example, the plural tray groups
attached to an image forming apparatus can be turned in a sectorial
form.
[0008] However, in the above examples, no technique is described
for clarifying the distribution of sheets when sorting the
sheets.
[0009] This invention provides a sheet processing apparatus that
enables discharge of sheets in a distributed manner to a
predetermined angular direction when performing sorting processing
of the sheets.
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic configuration view showing a sheet
processing apparatus according to an embodiment of this
invention.
[0011] FIG. 2 is a perspective view showing essential parts of the
sheet processing apparatus of this invention.
[0012] FIG. 3 is an explanatory view showing a paddle of the sheet
processing apparatus of this invention.
[0013] FIG. 4 is a schematic perspective view showing a
longitudinal alignment roller of the sheet processing apparatus of
this invention.
[0014] FIG. 5 is a schematic perspective view showing a standby
tray and a processing tray of the sheet processing apparatus of
this invention.
[0015] FIG. 6 is a top view showing the standby tray and the
processing tray of the sheet processing apparatus of this
invention.
[0016] FIG. 7 is a schematic perspective view showing a lateral
alignment plate and a transport belt of the sheet processing
apparatus of this invention.
[0017] FIG. 8 is a block diagram showing a control system of the
sheet processing apparatus of this invention.
[0018] FIG. 9 is an explanatory view showing an operation of
sorting processing in the sheet processing apparatus of this
invention.
[0019] FIG. 10 is an explanatory view showing another operation of
sorting processing in the sheet processing apparatus of this
invention.
[0020] FIG. 11 is an explanatory view showing still another
operation of sorting processing in the sheet processing apparatus
of this invention.
[0021] FIG. 12 is an explanatory view showing an operation of a
sheet discharge unit in the sheet processing apparatus of this
invention.
[0022] FIG. 13 is an explanatory view showing another operation of
the sheet discharge unit in the sheet processing apparatus of this
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Throughout this description, the embodiments and examples
shown should be considered as exemplars, rather than limitations on
the apparatus of the present invention.
[0024] Hereinafter, an embodiment of this invention will be
described in detail with reference to the drawings. In the
drawings, the same parts are described with the same reference
numerals.
[0025] FIG. 1 is a schematic configuration view showing a sheet
post-processing apparatus 2 with an image forming apparatus 1 such
as a copy machine arranged next to it. A paper P on which an image
has been formed by the image forming apparatus 1 is discharged from
paper discharge rollers 4 and transported to the sheet
post-processing apparatus 2. The paper discharge rollers 4 include
an upper roller 4a and a lower roller 4b.
[0026] The sheet post-processing apparatus 2 has a standby tray 10,
a processing tray 12, a stapler 14, a first paper discharge tray
16, a second paper discharge tray 18, and a fixed tray 20.
[0027] The paper P discharged by the paper discharge rollers 4 of
the image forming apparatus 1 is received by entry rollers 22
provided near an entry port of the sheet post-processing apparatus
2. The entry rollers 22 include an upper roller 22a and a lower
roller 22b and are driven by a motor (not shown).
[0028] Paper feed rollers 24 are provided downstream of the entry
rollers 22. The paper P received by the entry rollers 22 is sent to
the standby tray 10 via the paper feed rollers 24. Between the
entry rollers 22 and the standby tray 10, a paper path 23 for
guiding the paper P to the paper feed rollers 24 is provided. The
paper feed rollers 24 include an upper roller 24a and a lower
roller 24b.
[0029] The standby tray 10 has the papers P stacked thereon and is
structured to be openable. When a predetermined number of papers P
are stacked thereon, the standby tray 10 opens and the papers P
fall down to the processing tray 12 because of their own weight.
Below the standby tray 10, the processing tray 12 is provided on
which the papers P falling from the standby tray 10 are stacked.
The processing tray 12 aligns and supports the papers P while the
stapler 14 as a post-processing mechanism staples the papers P.
[0030] The papers that have fallen onto the processing tray 12 are
guided to the stapler 14 by rollers 28 and stapling processing is
performed. The rollers 28 include an upper roller 28 and a lower
roller 28b. In the case of performing stapling processing, the
plural papers P that have fallen onto the processing tray 12 from
the standby tray 10 are aligned in the longitudinal direction,
which is the transporting direction, and also aligned in the
lateral direction orthogonal to the transporting direction, and are
then stapled.
[0031] Turnable paddles 40 are arranged at a position to which the
rear end of the papers P falls when the papers P fall onto the
processing tray 12.
[0032] The paddles 40 are attached to a rotary shaft 26 and are to
slap down the papers P falling from the standby tray 10 onto the
processing tray 12 and thus send the papers P toward the stapler
14. The details of the paddles 40 will be later described with
reference to FIG. 3.
[0033] A stopper 45 that regulating the rear end position of the
papers P is provided at the end of the processing tray 12 near the
stapler 14. Also, a transport belt 50 is provided that transports
the sorted or stapled papers P to the first paper discharge tray 16
or the second paper discharge tray 18.
[0034] The transport belt 50 is laid between pulleys 36 and 38. The
transport belt 50 has a pawl member 50a attached thereto that hooks
the rear end of the papers P and sends them. The lower roller 28b
of the rollers 28 is arranged coaxially with the pulley 38. The
rollers 28 rotate in opposite directions when guiding the aligned
papers toward the stapler 14 and when discharging the stapled
papers P.
[0035] The pulley 36 is attached to a shaft 34, and plural
discharge rollers 30 are rotatably attached to this shaft 34. The
discharge rollers 30 will be described with reference to FIG.
2.
[0036] The papers P transported by the transport belt 50 are
discharged to the first paper discharge tray 16 or the second paper
discharge tray 18, and the first paper discharge tray 16 and the
second paper discharge tray 18 are lifted and lowered by a driving
unit (not shown) and thus receive the papers P.
[0037] Also, the papers P stacked on the standby tray 10 may be
discharged to the first paper discharge tray 16 or the second paper
discharge tray 18 without being stapled. In this case, the papers P
are discharged by a roller 32 without causing them to fall onto the
processing tray 12.
[0038] The standby tray 10 is arranged at an inclination angle of
.theta.1 to support the papers P in the state where the distal end
of the papers P is higher than their rear end. Also the paper
discharge trays 16 and 18 are arranged at an inclination angle
.theta.2 to support the papers P in the state where the distal end
of the papers P is higher than their rear end.
[0039] The papers P that do not require post-processing can also be
discharged to the fixed tray 20. A transport passage to guide the
papers P to the fixed tray 20 is provided, though not shown.
[0040] FIG. 2 is a perspective view of essential parts of the sheet
post-processing apparatus 2, as viewed from the direction of the
arrow x in FIG. 1.
[0041] In FIG. 2, the shaft 34 is arranged orthogonally to the
direction of transporting the papers P. The pulley 36 is attached
to an intermediate part of the shaft 34 and the belt 50 is laid on
this pulley 36. The discharge rollers 30 include central rollers
30a, 30a and side rollers 30b, 30c. The central rollers 30a are
attached to both sides of the pulley 36, and the turning of the
belt 50 causes the central rollers 30a to rotate, too.
[0042] The side rollers 30b and 30c are attached to two side parts
of the shaft 34. The side rollers 30b and 30c are symmetrically
arranged about the central rollers 30a.
[0043] The central rollers 30a rotate, interlocked with the driving
of the belt 50. The side roller 30b and the side roller 30c are
rotationally controlled by their respective driving units
synchronously with the rotation of the central rollers 30a, and
they rotate when discharging the papers P to the tray 16 or 18.
[0044] FIG. 3 shows the configuration of the paddle 40. The paddle
40 has its attachment member 41 attached to the rotary shaft 26.
The attachment member 41 includes a receiving part 42 that receives
the rear end of the papers P falling from the standby tray 10, a
slapping part 43 that slaps the papers P down onto the processing
tray 12, and a feed part 44 that feeds the papers P on the
processing tray 12 toward the stapler 14.
[0045] In the case of feeding the papers P on the processing tray
12 toward the stapler 14 (arrow q), the upper roller 28a of the
rollers 28 rotates counterclockwise and the lower roller 28b
rotates clockwise. In the case of discharging the papers P on the
processing tray 12, the upper roller 28a rotates in the direction
of the arrow r and the lower roller 28b rotates in the direction of
the arrow s.
[0046] The rotary shaft 26 is rotationally driven by a motor 54
(see FIG. 4). Alternatively, the rotation force of the motor can be
transmitted to the rotary shaft 26 via a gear mechanism. The
slapping part 43 and the feed part 44 of the paddle 40 are made of
a rubber material and are elastic.
[0047] As can be seen from FIG. 2, the plural paddles 40 are
attached to the rotary shaft 26. Moreover, guide members 52 are
provided to guide the papers to the processing tray 12. The guide
members 52 serve as guides when pulling the rear end of the
transported papers P toward the stapler 14.
[0048] FIG. 4 is a schematic perspective view showing the
configuration of the rollers 28 for longitudinal alignment of the
papers P and the transport belt 50. As shown in FIG. 4, the
transport belt 50 is laid between the pulleys 36 and 38 and is
rotationally driven by a motor 56, thus moving in a circulating
manner between the stapler 14 and a paper discharge port 100 (FIG.
1) along the direction of discharging the papers.
[0049] When transporting the papers P toward the paper discharge
trays 16 and 18, the transport belt 50 moves in the direction of
the arrow t and the upper roller 28a and the lower roller 28b for
longitudinal alignment rotate in the direction of the arrow r and
the direction of the arrow s shown in FIG. 3. The upper roller 28a
for longitudinal alignment is rotationally driven by a motor 58.
The lower roller 28b is rotationally driven by the motor 56, which
drives the transport belt 50.
[0050] FIG. 5 and FIG. 6 schematically show the standby tray 10 and
the processing tray 12. The standby tray 10 has a pair of tray
members 10a, 10b. They receive the papers P in the state of being
slid to the width of the papers P and support both sides of the
papers P. On the tray members 10a, 10b, standby stoppers 10c, 10d
to regulate the rear end of the papers P are provided.
[0051] The standby tray 10 is slid in the directions of the arrows
m and n by a motor (not shown). Before the papers P reach the
processing tray 12 from the standby tray 10, the papers P may
deviate in the lateral direction orthogonal to the transporting
direction when the papers P on the standby tray 10 are dropped and
supplied to the processing tray 12.
[0052] Therefore, a lateral alignment device 46 that prevents the
deviation of the papers P is provided, as shown in FIG. 7. The
lateral alignment device 46 has a pair of lateral alignment plates
47a, 47b. The lateral alignment plates 47a, 47b are slidable in the
direction v to fit the width of the papers P, and the alignment
position can be changed by a motor 48.
[0053] Also, the lateral alignment device 46 is used for sorting
and discharging papers by controlling the movement of the lateral
alignment plates 47a, 47b.
[0054] The driving units such as the motors 48, 54, 56 and 58 that
drive the above various mechanisms are drive-controlled by a
control circuit.
[0055] Next, a post-processing operation by the sheet
post-processing apparatus 2 will be described along the flow of
papers. The post-processed papers are discharged to either the
paper discharge tray 16 or the paper discharge tray 18.
Hereinafter, the case of discharging the papers to the paper
discharge tray 16 will be described as a representative
example.
[0056] The papers P transported from the entry rollers 22 via the
paper path ceiling 23 are supplied onto the standby tray 10 by the
paper feed rollers 24. Next, the papers P fall onto the processing
tray 12.
[0057] When the papers P fall, the upper roller 28a for
longitudinal alignment is retreating above and the receiving parts
42 of the paddles 40 receive the rear end of the papers P.
[0058] Then, the paddles 40 rotate in the direction of the arrow y
as shown in FIG. 3. The rear end of the papers P falls off the
receiving parts 42, and the slapping parts 43 slap the papers down
to the processing tray 12. The papers fall while both lateral sides
of the papers P contact the lateral alignment plates 47a, 47b, thus
performing lateral alignment. Moreover, the paddles 40 send the
papers P in the direction of the arrow q by the feed parts 44. As
the rear end of the papers P is abutted against the stopper 45,
longitudinal alignment of the papers P is completed.
[0059] In this way, the papers P on which images have been formed
are guided from the paper feed rollers 24 to the processing tray 12
while the papers are sequentially aligned laterally and
longitudinally.
[0060] In the case of performing stapling processing, when the
number of papers P stacked on the processing tray 12 has reached a
predetermined number, the stapler 14 staples the papers P on the
processing tray 12 at a desired position and thus forms a sheet
pack. After this, the upper roller 28a rotating in the direction of
the arrow r and the lower roller 28b rotating in the direction of
the arrow s, as shown in FIG. 3, nip and transport the sheet pack
toward the paper discharge tray 16.
[0061] When the rear end of the sheet pack has passed the rollers
28a, 28b, it is hooked by the feed pawl 50a of the transport belt
50, transported toward the paper discharge tray 16, and then
discharged onto the paper discharge tray 16 by the discharge
rollers 30.
[0062] Meanwhile, in the case of performing sorting processing as
post-processing, the lateral position of the papers P is shifted
one by one by the lateral alignment plates 47a, 47b and the papers
are thus discharged onto the paper discharge tray 16.
[0063] The overall operations of the sheet post-processing
apparatus 2 have been described above. Next, the configuration of a
sorting processing unit, which is a characteristic unit of this
invention, will be described.
[0064] FIG. 8 is a block diagram showing a control system that
controls the sorting processing unit. In FIG. 8, 60 denotes a
control circuit that controls the image forming apparatus 1. It is
formed by, for example, a microprocessor including a CPU and
controls an image forming unit 64 or the like in response to an
operation of an operating unit 62. The operating unit 62 has keys
for entering the number of print sheets and the like, and an
instruction unit 66 that instructs post-processing such as sorting
processing.
[0065] Numeral 70 denotes a control circuit that controls the sheet
post-processing apparatus 2. It is formed by, for example, a
microprocessor including a CPU, transmits information to and from
the control circuit 60 for the image forming apparatus 1, and
controls each part for sheet post-processing so that the image
forming operation and the operation of the sheet post-processing
apparatus 2 are linked with each other.
[0066] Also, the control circuit 70 is connected to a paper
discharge control unit 72 that controls the rotation of the
discharge rollers 30a, 30b, 30c, and to a sorting control unit 80
that controls the lateral alignment plates 47a, 47b to sort the
papers P.
[0067] The paper discharge control unit 72 has a first driver 74
that controls the turning or rotation of the transport belt 50 and
the discharge rollers 30a, a second driver 76 that controls the
rotation of the discharge roller 30b, and a third driver 78 that
controls the rotation of the discharge roller 30c.
[0068] The discharge rollers 30a, 30b, 30c are controlled by the
first driver 74, the second driver 76 and the third driver 78. When
discharging normal papers P, the discharge rollers 30a, 30b, 30c
rotate at the same speed synchronously with each other. However,
when discharging sorted papers P, the discharge rollers take
different rotation forms from each other.
[0069] Also, the sorting control unit 80 controls the motor 48
(FIG. 7) to slide the positions of the lateral alignment plates
47a, 47b.
[0070] FIG. 9 and FIG. 10 are explanatory views for explaining the
operations of the paper discharge unit under the control of the
control circuits 60 and 70.
[0071] In the case of sorting and discharging the papers P, for
example, in the case of making two copies of plural originals, then
sorting and discharging them, the papers P are shifted one by one
alternately in the direction of width by the lateral alignment
plates 47a, 47b and thus discharged to the paper discharge tray
16.
[0072] FIG. 9 shows a discharge state in ordinary sorting
processing. It shows an example in which the first paper P1 and the
second paper P2 are shifted in the direction of width and thus
discharged. The first paper P1 is shifted to the left in FIG. 9 by
the lateral alignment plates 47a, 47b (indicated by the solid
line). The second paper P2 is shifted to the right in FIG. 9 by the
lateral alignment plates 47a, 47b (indicated by the dotted line)
These papers are thus discharged to the paper discharge tray 16 by
the rotation of the discharge rollers 30a, 30b, 30c.
[0073] The third paper is discharged to the same position as the
first paper P1, and the fourth paper is discharged to the same
position as the second paper P2. The subsequent papers are
similarly discharged to the alternately shifted positions.
Alternately moving the lateral alignment plates 47a, 47b to shift
the papers P1, P2 is carried out by the sorting control unit
80.
[0074] FIG. 10 is for explaining another operation of sorting
processing according to this invention. FIG. 10 is similar to FIG.
9 in that the first paper P1 is shifted to the left in FIG. 10 by
the lateral alignment plates 47a, 47b (indicated by the solid line)
and the second paper P2 is shifted to the right in FIG. 10 by the
lateral alignment plates 47a, 47b (indicated by the dotted
line).
[0075] Also, the papers P1, P2 are discharged to the paper
discharge tray 16 by the rotation of the discharge rollers 30a,
30b, 30c, but the rotating states of the discharge rollers 30b, 30c
change before the papers are discharged to the paper discharge tray
16.
[0076] That is, while the first paper P1 is discharged toward the
paper discharge tray 16, the rotation speed of the discharge roller
30b becomes lower than the rotation speed of the discharge rollers
30a, and the rotation speed of the discharge roller 30c becomes
higher than the rotation speed of the discharge rollers 30a. Thus,
the discharge of the paper P1 at the left end in the direction of
width becomes slower and the discharge at the right end becomes
faster. Therefore, the paper P1, shifted to the left in FIG. 10, is
further inclined to the left and discharged.
[0077] On the other hand, when discharging the second paper P2,
while the second paper P2 is discharged toward the paper discharge
tray 16, the rotation speed of the discharge roller 30b becomes
higher than the rotation speed of the discharge rollers 30a, and
the rotation speed of the discharge roller 30c becomes lower than
the rotation speed of the discharge rollers 30a. Thus, the
discharge of the paper P2 at the left end in the direction of width
becomes faster and the discharge at the right end becomes slower.
Therefore, the paper P2, shifted to the right in FIG. 10, is
further inclined to the right and discharged.
[0078] As a result, the papers P1 and P2 are discharged to the
paper discharge tray 16 as they are inclined at a predetermined
angle into diffusing directions from each other. Similarly, the
subsequent papers are sequentially inclined at a predetermined
angle alternately in diffusing directions from each other and are
discharged to the paper discharge tray 16.
[0079] The first, second and third drivers 74, 76, 78 control the
rotation speeds of the discharge rollers 30a, 30b, 30c, and when
discharging the papers P1, P2, these rollers rotate at the same
rotation speed up to a certain point. Also, while the papers P1, P2
are discharged, the rotation speeds of the discharge rollers 30b
and 30c are relatively switched without changing the rotation speed
of the discharge rollers 30a, thus inclining the papers P1, P2.
[0080] Moreover, the rotation of the discharge rollers 30a, 30b,
30c is stopped immediately before the papers P1, P2 are discharged
to the paper discharge tray 16. Thus, the papers P1, P2 are
discharged to the paper discharge tray 16 by inertia.
[0081] As the rotation speed of the discharge rollers 30a is thus
kept constant and the rotation speeds of the discharge roller 30b
and the discharge roller 30c are alternately made higher or lower,
the papers can be inclined to different directions from each other
and discharged.
[0082] Also, since corners P01, P02 of the papers P1, P2 protrude
from the paper discharge tray 16, as shown in FIG. 10, one can take
out the papers P1, P2 by holding these corners P01, P02, and the
take-out after the sorting processing can be easier.
[0083] The directions of discharging the papers P1, P2 and the like
may be the opposite directions to those shown in FIG. 10. That is,
when the discharge of the left end of the paper P1 in the direction
of width is made faster and the discharge of the right end is made
slower, the paper P1 is inclined to the right and discharged, as
shown in FIG. 11. On the other hand, when the discharge of the left
end of the paper P2 in the direction of width is made slower and
the discharge of the right end is made faster, the paper P2 is
inclined to the left in FIG. 11 and discharged. Thus, the shifted
papers P1, P2 can be discharged into angular directions that cross
each other.
[0084] Also in this case, since corners P01, P02 of the papers P1,
P2 protrude from the paper discharge tray 16, as shown in FIG. 11,
one can take out the papers P1, P2 by holding these corners P01,
P02, and the take-out after the sorting processing can be
easier.
[0085] Also, since the paper discharge tray 16 is inclined at the
inclination angle 02 as described with reference to FIG. 1, the
discharged papers P1, P2 and the like slip and fall in this state.
The inclinations of the discharged papers may be lost, and this may
cause the state of FIG. 9.
[0086] Thus, a movable pin 90 is provided on the paper stacking
surface of the paper discharge tray 16, and in the case of
performing sorting processing, the pin 90 can be protruded from the
paper discharge tray 16. Thus, even when the papers P1, P2
discharged at predetermined angles are about to slip down because
of the inclination angle .theta.2 of the tray 16, it can be
prevented by the pin 90.
[0087] When the pin 90 is protruded, the thickness of the papers
stacked on the paper discharge tray 16 may exceed the height of the
pin 90 in some cases. Therefore, the pin 90 may be configured to
movably protrude from the body of the sheet post-processing
apparatus 1.
[0088] FIG. 12 shows the case where the pin 90 is protruded on the
paper stacking surface of the paper discharge tray 16. FIG. 13
shows the case where a pin 91 is protruded from the body of the
sheet post-processing apparatus 1.
[0089] Also, FIG. 12 is a view for explaining the state before the
papers P are discharged to the paper discharge tray 16, and FIG. 13
is a view for explaining the state after the papers P are
discharged to the paper discharge tray 16.
[0090] Moreover, the angle of the paper discharge tray 16 can be
made adjustable, instead of providing the pin 90 or 91. In this
case, when performing sorting processing and discharging papers,
the inclination angle .theta.2 can be decreased so that the paper
stacking surface becomes closer to a flat surface.
[0091] In this manner, according to this invention, a sheet
post-processing apparatus can be provided in which, when
discharging papers to the paper discharge tray, the papers are
distributed into different angular directions and thus discharged,
thus clarifying the distinction of the sorted papers.
[0092] This invention is not limited to the above description and
various modifications can be made without departing form the
claims. For example, stapled sheet packs can be sorted and
discharged. Also, the paper discharge control unit 72 may be
controlled in accordance with the mode selection by the user so
that a mode of discharging without inclination as shown in FIG. 9
and a mode of discharging with inclination as shown in FIG. 10 or
FIG. 11 can be selected.
[0093] Although exemplary embodiments of the present invention have
been shown and described, it will be apparent to those having
ordinary skills in the art that a number of changes, modifications,
or alterations to the invention as described herein may be made,
none of which depart from the spirit of the present invention. All
such changes, modifications, and alterations should therefore be
seen as within the scope of the present invention.
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