Information
-
Patent Grant
-
6634641
-
Patent Number
6,634,641
-
Date Filed
Tuesday, February 19, 200222 years ago
-
Date Issued
Tuesday, October 21, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Walsh; Donald P.
- Bower; Kenneth W
Agents
-
CPC
-
US Classifications
Field of Search
US
- 271 220
- 271 221
- 271 224
- 271 227
- 271 25801
- 271 265
- 270 5801
- 270 5802
- 270 5817
-
International Classifications
-
Abstract
An apparatus prevents unwanted stop caused by erroneous detection of a sheet when the sheet bends during a sheet bundle alignment or stapling. The apparatus includes a control device for ignoring a sheet presence detection result by a sensor lever and a sheet presence sensor when aligning by a paddle and an alignment plate or binding by a staple unit.
Description
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a sheet discharge apparatus to stack sheets with images thereon discharged from an image forming apparatus, such as a copier or printer, and an image forming apparatus with this sheet discharge apparatus, a sheet finishing apparatus that performs finishing process to stacked bundles of sheets and an image forming apparatus with this sheet finishing apparatus.
An apparatus that stacks sheets formed with images using an image forming apparatus, such as a copier or printer, onto a tray and to perform processes like aligning bundles of sheets stacked on the tray and to staple or punch holes into aligned sheet bundles, is well known.
However, in the conventional apparatuses, bending can develop in the sheet bundles, as shown in
FIG. 26
, when aligning the sheet S in the direction traversing the sheet transport direction by an aligning face
340
for moving the sheet S toward an aligning reference wall
341
. Furthermore, as can be seen in
FIG. 25
, bending can develop in the sheet bundle when aligning the sheet bundle in the transport direction by an aligning belt
180
for moving the sheet bundle toward the reference wall
290
. Still further, as can be seen in
FIG. 27
, when stapling a sheet bundle, the sheet bundle is lifted from the tray. Thus, sensors
30
and
31
for detecting the sheets on the tray are unable to accurately detect the presence of the sheet bundle which results in their erroneously detecting that the sheet bundle is not present based upon the signals from the sensors
30
and
31
, regardless of whether or not there is a sheet bundle present on the tray.
In such cases, the sheets from the subsequent job are discharged to the tray while aligning the sheet bundle or while stapling to cause those sheets by the subsequent job to become mixed into and processed with the sheet bundle of the current job which has already been discharged to the tray. So there are problems that the sheets from the subsequent job are discharged while aligning the sheet bundle or while stapling, to thereby strike the aligning means or the stapler to cause jams, or to crease paper, or the machine determines that the sheets had been removed from the tray and a sheet removing jam has occurred which will then cause the entire apparatus to stop operation.
Thus, in view of the situations described above, an object of the instant invention is to provide a sheet discharge apparatus to alleviate the above defects, to prevent jams or creasing of paper by accurately detecting the presence of sheets on the tray and to eliminate unnecessary apparatus stops.
SUMMARY OF THE INVENTION
In order to attain the above objectives, the sheet discharge apparatus of the present invention is equipped with sheet storage means for receiving sheets, discharge means for discharging the sheets transported from an image forming apparatus to the aforementioned sheet storage means, sheet detection means for detecting the presence of sheets on the aforementioned sheet storage means, aligning means for aligning the sheets discharged to the sheet storage means and control means that ignores the detection result of the aforementioned sheet detection means when aligning by using the aforementioned aligning means.
In order to attain the above objectives, the sheet finishing apparatus of the invention is equipped with sheet storage means for receiving sheets, discharge means for discharging the sheets transported from image forming apparatus to the aforementioned sheet storage means, sheet detection means for detecting the presence of the sheets on the aforementioned sheet storage means, aligning means for aligning the sheets discharged to the sheet storage means, finishing means for executing the prescribed finishing process on a sheet bundle aligned by the aforementioned aligning means and control means that ignores the detection results of the aforementioned sheet detection means when aligning by using the aforementioned aligning means or finishing by using the aforementioned finishing means.
In order to attain the aforementioned objectives, in the sheet discharging apparatus of the invention, the above sheet detecting means outputs signals used in the control of the discharge of the sheets from the aforementioned image forming apparatus.
In order to attain the aforementioned objectives, in the sheet finishing apparatus of the invention, the above sheet detecting means outputs signals used in the control of the discharge of the sheets from the aforementioned image forming apparatus.
In order to attain the aforementioned objectives, in the sheet discharging apparatus of the invention, the above sheet detecting means outputs signals used in the control to stop either the image forming apparatus or the sheet discharging apparatus.
In order to attain the aforementioned objectives, in the sheet finishing apparatus of the invention, the above sheet detecting means outputs signals used in the control to stop either the image forming apparatus or the sheet discharging apparatus.
In order to attain the above objectives, the image forming apparatus of the invention is equipped with sheet storage means for receiving sheets, discharge means for discharging the sheets transported from an image forming apparatus to the aforementioned sheet storage means, sheet detection means for detecting the presence of the sheets on the aforementioned sheet storage means, aligning means for aligning the sheets discharged to the sheet storage means and control means for ignoring the detection results of the aforementioned sheet detection means when aligning by using the aforementioned aligning means.
In order to attain the aforementioned objectives, in the image forming apparatus according to the invention, the aforementioned sheet detecting means outputs signals used in the control of the discharge of the sheets from the aforementioned image forming apparatus.
In order to attain the aforementioned objectives, in the image forming apparatus according to the invention, the aforementioned sheet detecting means outputs signals used in the control to stop either the aforementioned image forming apparatus or the aforementioned sheet discharge apparatus.
In order to attain the above objectives, the image forming apparatus of the instant invention is equipped with sheet storage means for receiving sheets, discharge means for discharging the sheets transported from an image forming apparatus to the aforementioned sheet storage means, sheet detection means for detecting the presence of the sheets on the aforementioned sheet storage means, aligning means for aligning the sheets discharged to the sheet storage means, a sheet finishing apparatus comprising finishing means for executing a prescribed finishing process on a sheet bundle aligned by the aforementioned aligning means, and control means for ignoring the detection results of the aforementioned sheet detection means when aligning by using the aforementioned aligning means or finishing by using the aforementioned finishing means.
In order to attain the aforementioned objectives, in the image forming apparatus according to the invention, the aforementioned sheet detecting means outputs signals used in the control of the discharge of the sheets from the aforementioned image forming apparatus.
In order to attain the aforementioned objectives, in the image forming apparatus according to the invention, the aforementioned sheet detecting means outputs signals used in the control to stop the aforementioned image forming apparatus or the aforementioned sheet discharge apparatus.
The other objectives and features of the invention will be made clear by a detailed description below, according to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
shows a general perspective view of a part of a sheet storage apparatus of the first type of an embodiment of the present invention;
FIG. 2
is a sectional view of the general internal structure of the apparatus shown in
FIG. 1
;
FIG. 3
is an enlarged view of the parts shown in
FIG. 2
;
FIG. 4
is a general perspective view of a part of the sheet temporary stacking tray of the apparatus shown in
FIG. 1
;
FIG. 5
is a front sectional view of sheet pressing means on a sheet temporary stacking tray of the apparatus shown in
FIG. 1
;
FIG. 6
is a general perspective view of the sheet pressing means on the sheet stacking tray shown in
FIG. 5
;
FIG. 7
is a sectional view of another embodiment of the sheet pressing means shown in
FIG. 5
;
FIG. 8
is a partly sectional plan view of the general structure of a rotating unit of the apparatus shown in
FIG. 1
;
FIG. 9
is a sectional view of a drive transmission system of the apparatus shown in
FIG. 1
;
FIG. 10
is a conceptual perspective view of a part of the drive transmission system shown in
FIG. 9
;
FIGS.
11
(A)-
11
(C) are explanatory views showing the operation of a drive transmission system (1) shown in
FIG. 9
;
FIGS.
12
(A) and
12
(B) are explanatory views showing the operation of a drive transmission system (2) shown in
FIG. 9
;
FIGS.
13
(A) and
13
(B) are front sectional views of the general stacking tray;
FIGS.
14
(A) and
14
(B) are explanatory views showing the operation of the sheet stacking on a stacking tray (1);
FIGS.
15
(A) and
15
(B) are explanatory views showing the operation of the sheet stacking on a stacking tray (2);
FIG. 16
is a conceptual view of another embodiment of a pressing lever that presses the sheets on the stacking tray shown in
FIG. 2
;
FIG. 17
is a conceptual view of another embodiment of the pressing lever that presses the sheets on the stacking tray shown in
FIG. 2
;
FIG. 18
shows a front sectional view of the internal mechanism of the sheet storage apparatus of the second type of another embodiment of the apparatus shown in
FIG. 1
;
FIG. 19
is perspective view showing the internal mechanism of the temporary stacking tray omitting a part of the apparatus shown in
FIG. 13
;
FIG. 20
is a perspective view of a feed belt unit shown in
FIG. 18
;
FIG. 21
is a perspective view of another embodiment of the feed belt and the unit shown in
FIG. 20
;
FIG. 22
is a front perspective view of the stacking tray mounted to the apparatus shown in
FIG. 18
;
FIG. 23
is a partial sectional view of the mechanism to detect the position of the pressing lever that presses sheets into the stacking tray of the apparatus shown in
FIG. 18
;
FIGS.
24
(A) and
24
(B) are explanatory views showing the operation of the sheet stacking on the stacking tray;
FIG. 25
is a front sectional view of the internal structure of the conventional sheet storage apparatus;
FIG. 26
is a sectional view of the aligning mechanism of the conventional sheet storage apparatus;
FIG. 27
is a sectional view of the stapling mechanism of the conventional sheet storage apparatus;
FIG. 28
is a perspective view of the relationship of the arrangement of a weight member and an endless transport belt;
FIG. 29
is a plan view of the relationship of the arrangement of the weight member and the endless transport belt;
FIGS.
30
(A)-
30
(D) are sectional views for showing the movement of the weight member and the endless transport belt;
FIGS.
31
(A)-
31
(C) are sectional views of another embodiment relating to the weight member;
FIGS.
32
(A) and
32
(B) are sectional views of another embodiment relating to the weight member;
FIGS.
33
(A)-
33
(D) are sectional views of another embodiment relating to the movement of the weight member and the endless transport belt;
FIGS.
34
(A) and
34
(B) are sectional views of another embodiment relating to the weight member;
FIG. 35
is a flowchart showing the control of the apparatus after the sheet inlet sensor is OFF;
FIG. 36
is a flowchart showing the control of a paddle after the sheet inlet sensor is OFF;
FIG. 37
is a flowchart showing the control of an aligning plate after the sheet inlet sensor is OFF;
FIG. 38
is a flowchart showing the control of a staple unit after the sheet inlet sensor is OFF; and
FIG. 39
is a flowchart showing the control of a presence sensor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention relates to a sheet storage apparatus with improved stacking performance when temporarily stacking sheets before discharging with improved placing performance. The following will describe embodiments according to the drawings.
In
FIGS. 1
to
3
, as the sheet storage apparatus, a finisher apparatus
1
is disposed next to an image forming apparatus G, such as a copier or printer. In this case, preferably, it is removably mounted to the image forming apparatus G.
The image forming apparatus G comprises a photosensitive drum that can form a latent image on its outer circumference using an optical system, not shown in the drawings, a developer to develop a toner image of the latent image formed on the photosensitive drum, a cleaner to clean the photosensitive drum, transfer rollers to transfer the toner image formed on the outer circumference of the photosensitive drum in contact with the photosensitive drum through the sheet, and image forming means composed of a fixer to heat the toner transferred to a sheet and to fix it thereto to form the images on the sheets using this image forming means.
The sheets formed with the images using this image forming apparatus are discharged to the finisher apparatus
1
by discharge means, such as discharge rollers, which are not shown in the drawings.
This finisher apparatus
1
is equipped with a main apparatus
2
, a staple unit
3
which is mounted to a side frame
2
a
on one side of the main apparatus
2
, a drive transmission system
4
(see FIG.
9
and FIG.
10
), described later, arranged on a side frame
2
b
on the other side of the main apparatus
2
, an inlet
8
to which a sheet S formed with the images and discharged from the image forming apparatus G is supplied, a discharge outlet
10
formed on the side opposing the inlet
8
, a stacking tray
5
that protrudes from the front of the main apparatus
2
to stack the sheet S discharged from the discharge outlet
10
and an escape tray
6
positioned above the stacking tray
5
to store the sheets discharged from the second discharge outlet
12
.
As is shown in
FIG. 3
, internally disposed on the main apparatus
2
are a first transport path P
1
that leads the sheet S from the inlet
7
inside, a second transport path P
2
that connects from the first transport path P
1
directly to the stacking tray
5
through the discharge outlet
10
and via a discharge path, a third transport path P
3
to switchback the direction of transport of the sheet S with a space with respect to the second transport path P
2
to the processing tray
29
as the temporary stacking tray for temporary storage, and a fourth transport path P
4
that branches from the aforementioned first transport path P
1
to lead the sheet S to a second discharge outlet
12
.
In other words, the invention comprises a “pass-through mode” wherein the sheet S passes from the first transport path P
1
to the second transport path P
2
to discharge it to the stacking tray
5
; a “staple mode” wherein the sheet S is switched back and transported from the second transport path P
2
along the third transport path P
3
, and a plurality of sheets is aligned on the processing tray
29
and is bound using the staple unit
3
, and the sheet bundle is discharged to the stacking tray; and an “escape mode” wherein the sheet S is transported from the first transport path P
1
to the fourth transport path P
4
and is discharged to the escape tray
6
.
In the first transport path P
1
, there are disposed transport guides
8
to guide and transport the sheet S supplied from the inlet
7
, an inlet sensor
11
to detect that the sheet has been supplied, a transport drive roller
15
cooperating with a follower roller
14
to send the sheet S further downstream and a rotating type flapper
11
that switches transport path to guide the sheet S transported by the transport drive roller
15
toward endless transport belts
18
as sheet transport means to feed the sheet further forward or to guide the sheet S toward the fourth transport path P
4
.
The aforementioned endless transport belts
18
transport the sheet S to the second transport path P
2
in cooperation with the follower roller
17
. Note that the transport belt
18
is composed of an endless ring type belt and it is rotated by a belt drive roller
19
that is fastened to a drive shaft
19
a
. It is flexible to allow it to be deformed in the up and down directions or directions traversing thereto in FIG.
2
and FIG.
3
.
Below the endless transport belts
18
, there is disposed a processing tray unit
20
. This processing tray unit
20
is for temporarily holding the sheets S to be stapled by a staple unit
3
placed in order thereupon.
Note that in the present embodiment, the processing tray unit
20
is described for stapling to bind a determined number of sheets but it is also perfectly acceptable to punch holes in the sheets or to temporarily hold a plurality of sheet S to align them before discharging to the stacking tray
5
.
Also, above the aforementioned second transport path P
2
, there is established a rotating unit
24
that moves up and down using a paddle drive roller shaft
21
a
as a pivot. The rotating unit
24
is positioned in the downward position, which is shown in the position of the line in
FIG. 2
, when discharging the sheet S from the first transport path P
1
to the stacking tray
5
passing directly through the discharge outlet
10
or when discharging a plurality of sheet bundles in the aforementioned processing tray unit to the stacking tray
5
. When leading the sheet S to the third transport path P
3
inside the processing tray
29
, it is positioned in the upward position shown as the dotted line in FIG.
2
.
Inside of the rotating unit
24
, there are established a rubber paddle
23
disposed on a paddle rotation shaft
22
to follow the rotation of the paddle drive roller
21
on the paddle drive roller shaft
21
a,
and a follower discharge roller
25
established on the free end of the rotating unit
24
. This follower discharge roller
25
works in cooperation with a discharge roller
26
positioned below to discharge the sheet bundles from the discharge outlet
10
to the stacking tray
5
.
The aforementioned discharge roller
26
that is rotationally driven by a drive shaft
26
a
in opposition to the follower discharge roller
25
is disposed on the discharge outlet
10
of the main apparatus
2
.
At the bottom of the aforementioned discharge roller
26
, a front frame of the main apparatus
2
is integrally formed with a sheet abutting surface
2
c
in one unit as a sheet edge regulating member to restrict the edge of the sheet S stacked in the stacking tray
5
. A sheet holding lever
78
is disposed to appear by protruding toward the aforementioned stacking tray
5
from the upper position of the sheet abutting surface
2
c
near the discharge roller
26
on the sheet abutting surface
2
c
. This sheet holding lever
78
moves to protrude toward the stacking tray
5
whenever the sheet S or bundle of the sheet S is discharged by the follower discharge roller
25
. Therefore, the sheet holding lever
78
, which is described in further detail below, holds the edges of the sheets that are stacked. This improves the stacking performance of the sheets S in the stacking tray
5
and prevents the jamming of the sheets S when the edge of the sheet S discharged and stacked into the stacking tray
5
curls and the leading edge of subsequently discharged sheet S comes into contact with them.
Note that the sheet holding lever
78
according to the invention is driven by a holding lever solenoid
83
which is positioned behind the sheet abutting surface
2
c
to appear from inside the sheet abutting surface
2
c.
A transport guide
13
is disposed in the fourth transport path P
4
and is equipped with a second discharge roller
28
that cooperates with the follower roller
27
to discharge the sheet S from the second discharge outlet
12
into the escape tray
6
when the sheet S having images formed thereupon is not to be finished by using the stapling or sorting functions, or when a special sheet of a non-standard size is used.
The above description is a general explanation of the main apparatus
2
. The following will describe the configuration of each unit and each mechanism according to
FIG. 2
to FIG.
7
.
As is clearly shown in FIG.
3
and
FIG. 4
, the processing tray unit
20
is provided with a processing tray
29
as the temporary stacking tray for temporarily stacking the sheets to staple them, a sensor lever
30
a
to detect the sheet S being discharged to the processing tray
29
, a sheet holder
31
as sheet pressure means disposed in two locations, front and back, positioned in the direction of sheet transport to touch the upper most surface of the sheet on the processing tray
29
, and an alignment plate
34
as the aligning means for aligning the sheet S stacked upon the processing tray
29
.
The processing tray
29
is formed into a unified body with a sheet stacking portion
29
a
which is inclined upward in the leading edge direction of the discharge of the sheet bundle after binding and a process sheet leading edge restricting portion
29
b
as a reference member to align the edge of the sheet by abutting against the edge thereof on the sheet stacking portion
29
a,
that rises from the back edge of the sheet stacking portion
29
a.
Furthermore, the width of the processing tray
29
is larger than the size of the width of the maximum size sheet S, but it is possible for the length of the sheet transport direction to be short, in other words, the distance from the inlet
7
to the discharge outlet
10
, regardless of the sheet size. This is because the structure enables the sheets to be stacked while overlapping the processing tray
29
and the stacking tray
5
.
One edge of a sensor lever
30
extends into the second transport path P
2
on the discharge outlet
10
side and is rotationally supported by a sensor rotation shaft
30
c
below the processing tray
29
and comprises a sensor flag
30
b
that detects by the sheet presence sensor
30
a
on the other edge. When no sheet S is present, one edge extends into the second transport path P
2
separating from the sheet stacking portion, as can be seen in FIG.
2
and FIG.
3
.
The sensor lever
30
detects the status of the sheet S when the sheet S is not transported into the second transport path P
2
and when it is not stacked in the sheet stacking portion
29
a
on the processing tray
29
.
Therefore, when the sheet S is not stacked in the sheet stacking portion
29
a,
and when one sheet at a time passes through from the first transport path P
1
to the second transport path P
2
to the stacking tray
5
, it functions as the transport through sensor for the sheet S, detecting the trailing edge of the sheet S being discharged.
Furthermore, even when discharging the bundle from the processing tray
29
, it can detect as the sheet S bundle discharge through sensor. The pass through detection signal generated by the sensor lever
30
is used as a holding lever solenoid
83
activation signal to activate the sheet holding lever
78
, described above.
A sheet middle support guide
42
is disposed on the discharge outlet
10
side of the sheet stacking portion
29
a
positioned slightly upward from the outer circumference of the discharge roller
26
.
Note that the finisher apparatus
1
switches back the sheet S from the second transport path P
2
to the third transport path P
3
and places it on the processing tray
29
, in which the sheet S is placed at one time to overlap the processing tray
29
and the stacking tray
5
because the processing tray
29
is set to be shorter than the length of the sheet S transport direction, as described above.
Therefore, to shift the sheet in the width direction substantially traversing the transport direction of the sheet S to align the sheet on the processing tray
29
, it is preferred that the sheet S does not contact the discharge roller
26
formed of a material of a high coefficient of friction, such as rubber, and that the sheet S has firmness forming a bend at the top of the discharge roller.
On the other hand, when discharging the sheet S directly to the stacking tray
5
from the first transport path P
1
to the second transport path P
2
without placing it on the sheet stacking portion
29
a,
it is preferred that the discharge roller
26
and sheet S should not contact when the leading edge of the sheet S passes through the discharge roller
26
. The above sheet middle support guide
42
is disposed to achieve this.
Note that the sheet middle support guide
42
, in association with the up and down movements of the rotation unit
24
, is positioned further inside from the surface of the outer circumference of the discharge roller
26
when the rotating unit is in the downward position indicated by the line in FIG.
2
.
As can be seen in
FIG. 4
, the aligning unit
33
includes an alignment plate
34
arranged in a position traversing the transport direction of the sheet S, an alignment plate drive motor
36
, a pinion gear
37
fastened to an output shaft
36
a
on the alignment plate drive motor
36
, a rack gear
39
meshing with a pinion gear
37
established on the bottom of the alignment plate
34
, an alignment plate position detection sensor
35
to detect the position of the alignment plate
34
below the rack gear
39
, and an alignment plate flag
38
which is unitized with the rack gear
39
to interrupt the sensor.
Therefore, the alignment plate
34
moves to touch the sheet S in the direction traversing the direction of transport of the sheet S by the rotational drive of the alignment plate drive motor
36
whenever the sheet S is transported along the third transport path P
3
to the processing tray
29
. This touches the sheet S against the main apparatus side frame
2
a
to which the staple unit
3
is mounted in a position opposing the direction of travel of the alignment plate
34
.
Note that in the present embodiment, the alignment plate
34
is disposed on only one side in the width direction of the sheet S, but it is also perfectly acceptable to align the sheet S using paired alignment plates that approach to and separate from each other on both sides in the width direction of the sheet S.
The following will describe the endless transport belts
18
. As described above, the sheet S is transported in the direction of the second transport path P
2
in cooperation with the follower roller
17
, but this is configured in the third transport path P
3
to transport the sheet S toward the sheet leading restricting portion
29
b.
In other words, as can be seen in FIG.
3
and
FIG. 4
, the endless transport belts
18
act as the sheet feeding portion to transport the sheet S further in the third transport path P
3
, by forming fine teeth on the surface abutting against the sheet S and the portion
18
a
in the drawings acts as the sheet draw-in transport portion to draw in the sheet from the first transport path P
1
. A part
18
b
cooperates with the paddle
23
, described below, acts as a pushing portion to push the trailing edge in the direction of the transport of the sheet S from the second transport path P
2
to the third transport path P
3
. The endless transport belt
18
is composed of a flexible and deformable material so the sheet feeding portion
18
c
rises according to the thickness of the sheet S even if the sheets S are stacked on the stacking portion
29
a.
To describe the positional relationships of the endless transport belts
18
and the aforementioned alignment plate
34
, the sheet feeding portions
18
c
on the endless transport belts
18
are positioned within the range of the length in the transport direction of the alignment plate
34
, as can be seen in FIG.
3
and FIG.
4
. The alignment plate
34
shifts to move the sheet S in the width direction after the endless transport belts
18
transport the edge of the sheet S to reach the sheet leading restricting portion
29
b.
However, because the sheet S and the sheet feeding portion
18
c
are in contact when aligning, rotation force acts on the sheet S around the sheet drawing portion
18
c
when the sheet drawing portion
18
c
is positioned on the outside of the alignment plate
34
to prevent mal-alignment. Also, by arranging the sheet drawing portion
18
c
inside the alignment plate
34
, it is possible to shorten the overall length of the main apparatus
2
in the direction of sheet transport to make the apparatus more compact.
The following will describe the sheet pressing members
31
and
32
that are arranged above the sheet stacking portion
29
a
according to FIG.
5
and FIG.
6
. As described above, the sheet S to be placed on the processing tray
29
is fed sequentially to the sheet stacking portion
29
a
by the endless transport belts
18
along the third transport path P
3
. At this time, the sheet S is transported while being pushed against the sheet stacking portion
29
a
by the first sheet pressing member
31
and the second sheet pressing member
32
that are rotationally mounted to the support member
40
above the processing tray
29
. Even if the sheet S curls after its leading edge reaches the sheet leading restricting portion
29
b
on the processing tray
29
, it will not result in preventing the subsequent sheet from being transported in or good alignment for later finishing processes such as binding by staples.
In other words, the first sheet pressing member
31
hangs down to a position touching the sheet stacking portion
29
a
with a reference portion
31
a
rotationally mounted to a support shaft
40
a
on a support member
40
inside the support member
40
and the leading edge portion
31
b
adjacent to the sheet leading restricting portion
29
b
on the processing tray. Furthermore, the reference portion
31
a
on the first sheet pressing member
31
is positioned to overlap a portion of the sheet leading restricting portion
29
b
on the processing tray. This overlap prevents the edge of the sheet S from passing over the gap between the leading edge portion
31
b
and the sheet leading restricting portion
29
b.
Next, the second sheet pressing member
32
is rotationally mounted to a second support shaft
40
c
in which the reference portion
32
a
is mounted to the support member
40
, the leading edge portion
32
b
hangs downward toward the sheet stacking portion
29
a
from the endless transport belts
18
.
As can be seen in
FIG. 5
, a stopper portion
32
c
touches a restricting portion
40
d
disposed on the support portion
40
b
so the second sheet pressing member
32
maintains the distance h with the sheet stacking portion
29
a.
Therefore, the leading edge portion
32
b
does not touch the sheet S if the thickness of the sheet S stacked on the sheet stacking portion
29
a
does not exceed the aforementioned h distance.
In this way, the lead edge
32
b
on the second sheet pressing member
32
is made to separate from the sheet stacking portion
29
a
to reduce the resistance and damage to the sheet S when there is a fewer number of the sheets S and to touch the sheets S to create a bundle thereof when the prescribed number of sheets (more than the distance h) is reached or there is a curl in the sheet S that exceeds the distance of h.
Therefore, when there is a small number of sheets S to be stacked on the sheet stacking portion
29
a
or when there is a smaller curl thereof, the sheet S is pushed by the first sheet pressing member
31
alone. As the number of sheet S to be stacked increases or when curling is large, the second sheet pressing member
32
pushes the sheet S.
When the curl in the sheet S is large, like the sheet S indicated by the dotted line in
FIG. 5
, the leading edge portion
32
b
on the second sheet pressing member
32
touches and abuts against the rear portion
31
c
on the first sheet pressing member
31
. Thus, when a curl occurs in the sheet S that exceeds a predetermined amount, the weight of the first sheet pressing member
31
is applied to the leading edge portion
32
b
on the second sheet pressing member
32
to quickly alleviate this curl.
Note that the second sheet pressing member
32
whose leading edge portion
32
b
separates from the sheet stacking portion
29
a
is positioned further upstream in the direction of the sheet transport relative to the first sheet pressing member
31
when the sheet S is transported into the processing tray
29
. According to the present embodiment, when there is a fewer number of the sheets S transported in, only the first sheet pressing member
31
near the sheet leading restricting portion
29
b
pushes the sheet S. As the number of the sheet S transported in increases, both the first sheet pressing member
31
and the second sheet pressing member
32
act to push the sheets S. Furthermore, as the number of the sheets S increases, so does the pushing force on the sheets and the stacking performance of the sheets is improved.
Furthermore, as can be seen in
FIG. 6
, the first sheet pressing member
31
and the second sheet pressing member
32
are arranged in series along the width direction of the sheet S and are arranged to push the edges of the sheets stacked on the sheet stacking portion
29
a.
Therefore, finishing processes on the sheet edges, such as binding the sheet bundle using the staple unit
3
can be performed with the edges of the sheets correctly aligned.
Furthermore, according to the aforementioned embodiment, the leading edge portion
31
b
on the first sheet pressing member
31
is arranged so that it rests on the sheet stacking portion
29
a
when there is no sheet stacked thereupon, but it is also perfectly acceptable to have it not touch the aforementioned sheet stacking portion. In such a case, it is possible to set the distance of the leading edge portion
31
b
of the first sheet pressing member
31
with respect to the sheet stacking portion
29
a
to be smaller than the distance h for the leading edge portion
32
b
of the second sheet pressing member
32
with respect to the sheet stacking portion
29
a.
Also, although the first sheet pressing member
31
and the second sheet pressing member
32
are aligned in series of two in the direction of sheet transport, it is possible to use 3 or 4 series to vary the pushing pressure applied to the sheet S or in the same line.
Furthermore, it is acceptable to omit the second sheet pressing member
32
, as shown in the
FIG. 7
, and to dispose the coil spring
40
f
between the support member
40
and the first sheet pressing member
31
. One end of the coil spring
40
f
is positioned on the spring pin
40
e
disposed on the support member
40
and the other end of the spring touching portion
40
g
on the back side of the first sheet pressing member
31
. Therefore, when there is a fewer number of the sheets S, there is no action of the elastic force of the coil spring
40
f
but as the number of the sheet S increases, so does the strength of the elastic force of the coil spring
40
f
to increase the pressing force against the sheet S.
The sheets S stacked on the processing tray
29
are bound by the staple unit
3
, but the staple unit
3
according to the present embodiment is arranged obliquely in substantially the same angle as the sheet stacking portion
29
a
on the processing tray
29
and is mounted to the side frame
2
a.
This staple unit is disposed with a drive head portion
3
a
to drive the staples into the front edge of the sheet S, facing the sheet stacking portion
29
a
positioned inside from the main frame
2
, and an anvil portion
3
b
that bends the staple drive by the drive head portion
3
a.
It is further equipped with the replaceable cartridge
3
c
that stores the staples in the rear which is the outer side of the main apparatus frame
2
.
Note that the staple unit
3
drives the staple from the top surface of the sheets on the sheet stacking portion
29
a
but it is perfectly acceptable to reverse the positions of the drive head portion
3
a
and the anvil portion
3
b
to drive the staple from the undersurface of the sheet S.
Next, the description is made for the rotating unit
24
which is positioned above the sheet discharge outlet of the processing tray
29
in FIG.
3
. As can be seen in the plan view of
FIG. 8
, this rotating unit
24
is equipped with the paddle
23
, a paddle rotation shaft
22
that rotates the paddle
23
, a paddle drive belt
22
a
that transmits driving power to the paddle rotation shaft
22
, a paddle drive roller
21
that drives the paddle drive belt
22
a
and the follower discharge roller
25
that cooperates with the discharge roller
26
on the main apparatus frame
2
positioned at the discharge outlet
10
to discharge the sheet S. The paddle drive roller
21
is rotationally driven by the paddle drive roller shaft
21
a
that is rotationally driven by the paddle drive transmission gear
54
which is a part of the drive transmission system
4
established on the main apparatus side frame
2
a.
Also, the rotating unit
24
swings up and down to a position near the discharge roller
26
and a position away from the discharge roller
26
by using the paddle drive roller shaft
21
a
as the pivot. These up and down swinging actions are made by engaging the elevator pin
46
b
that protrudes from the elevator lever
64
disposed on the drive transmission system
4
, with the rotating unit
24
.
The rotating unit
24
is mounted on the shaft pivot of the paddle drive roller shaft
21
a
on one side attached to the main apparatus frame
2
, the other being constantly urged to the downward side of the discharge roller
26
by the rotating unit spring
24
b
that touches the rotating unit
24
frame, but the up and down swingings are controlled by the aforementioned elevator lever
64
in resistance to this urging force.
The main apparatus
2
includes the “pass-through mode” wherein the sheet S passes from the first transport path P
1
to the second transport path P
2
to discharge it to the stacking tray
5
; the “staple mode” wherein the sheets S are transported backwardly from the second transport path P
2
along the third transport path P
3
, aligned on the processing tray
29
, bound by using the staple unit
3
and discharged to the stacking tray; and the “escape mode” wherein the sheet S is transferred from the first transport path P
1
to the fourth transport path P
4
and discharged to the escape tray
6
.
The following describes the system that drives the transport drive roller
15
, the endless transport belts
18
, the discharge roller
26
, the paddle
23
, the elevator unit
24
, and the second discharge roller
26
.
As is shown in FIG.
9
and
FIG. 10
, the drive transmission system
4
according to the instant invention comprises one of drive motors
43
, an output pulley
44
that rotates in the counter-clockwise direction disposed on an output shaft
43
a
on this one drive motors
43
, a drive pulley
45
disposed on the rotation shaft
15
a
on the transport drive roller
15
arranged on the inlet
10
side, a drive pulley
47
disposed on the rotating shaft
28
a
on the second discharge roller
26
, a drive pulley
46
disposed on the rotation shaft
19
a
on the drive roller
19
to rotationally drive the endless transport belts
18
, a rotation belt
48
to transmit the drive from the output pulleys to each of the drive pulleys
45
,
46
and
47
, a large diameter timing gear
55
connected to a transmission gear
51
via a follower transmission gear
53
disposed on the rotation shaft
19
a
which is the same shaft as the drive pulley
46
, a transmission gear
56
b
that is connected via the timing gear
55
and the intermediate gear
56
a
disposed on the rotation shaft
26
a
on the discharge roller
26
, a paddle transmission gear
54
that is equipped with a rocking plate
54
c
on the outer circumference connected to the transmission gear
51
which is the same shaft as the follower transmission gear
52
and the drive pulley
46
, established on the paddle drive roller shaft
21
a
to rotationally drive the paddle drive roller
21
while supporting the rotating unit
24
to swing up and down, a paddle drive belt
22
a
that connects the paddle rotation shaft
2
that supports the paddle drive roller
21
and the paddle
23
, a cam
65
mounted on the timing gear
55
, and an elevator lever
64
that engages the rotating unit
24
by a pin
64
b
to swing the rotating unit
24
up and down with the rotation of the cam
65
.
In the drawings, numbers
49
and
50
are the tension rollers that apply tension to the rotating belt
48
.
The sheet S is fed from the inlet on the main apparatus
2
. When the inlet sensor
8
b
detects that the machine is in operation by detection the leading edge of the sheet S, the transport drive motor
43
starts up and the rotating belt
48
rotates the transport drive roller
15
connected to the drive pulley
45
, the second discharge roller
26
connected to the drive pulley
47
and the drive roller
19
to drive the endless transport belts
18
connected to the drive pulley
46
, to continuously rotate in the direction of sequentially feeding the sheets, i.e. in the sheet transport direction.
When processing the sheet S using the “pass-through mode”, the timing drive gear
55
is rotated without rotationally driving the paddle
23
. This rotation moves the elevator lever
64
downward shown in the drawing thereby moving the rotating unit
24
also to the side of the follower discharge roller
26
to touch to the follower discharge roller
26
inside the rotating unit
24
. Along with this, the discharge roller
26
rotates via the intermediate gear
56
a
and the transmission gear
56
b,
and the timing drive gear
55
discharges the sheet S one by one to the stacking tray
5
along the second transport path P
2
.
Alternatively, in the “staple mode”, when the trailing edge of the sheet S passes the inlet sensor
11
and the sensor turns OFF (S
1001
, as indicated in the flow chart in FIG.
35
), it sets the prescribed pulse to start up the paddle
23
(S
1002
) and begins to count down the pulse that was set (S
1101
).
The prescribed pulse to start up the paddle
23
is set for the trailing edge of the sheet S to pass the endless belt drive roller
19
and the follower roller
17
, so that when the aforementioned set prescribed pulse is counted down to 0 (S
1102
), the paddle
23
starts (S
1103
) and the activating pulse is set to operate the paddle
23
at substantially the same time (S
1104
) and rotates in the direction opposite to the direction of sheet transport (the opposite direction of the drive roller
19
) to feed the sheet S from the second transport path P
2
to the processing tray
29
along the third transport path P
3
.
The activating pulse set after the aforementioned startup pulse is surpassed is counted down (S
1105
) to continuously rotate the paddle
23
until the activating pulse count is counted down to O(S
1106
), and then it stops (S
1107
).
The startup pulse for the alignment plate
34
is set after setting the startup pulse for the aforementioned paddle
23
, as shown in
FIG. 35
(S
1003
).
Note that if there is a plurality of sheets discharged to the processing tray
29
, after the alignment plate
34
starts from its prescribed home position to align the sheets, it moves to an idling position closer to the edge of the sheets than the home position and returns to its home position from the idling position after aligning the second and subsequent sheets.
The startup pulse for the aforementioned alignment plate
34
is set to start after the edge of the sheet S reaches the sheet leading restricting portion
29
b
on the processing tray
29
by the paddle
23
.
Then, when the startup pulse for the alignment plate
34
is counted down (S
1201
) to 0 (S
1202
), the activating pulse required is set to move the alignment plate
34
from its prescribed home position for the first sheet and from the aforementioned idling position for the second and subsequent sheets, and at substantially the same time, the alignment plate
34
is started (S
1203
) to push each sheet against the main apparatus side frame
2
a
for each sheet (S
1204
).
At the point (S
1206
) where the aforementioned activating or operation pulse is counted down to 0 (S
1205
), the alignment plate
34
is stopped at either the idling position or the home position according to the activating pulse (S
1207
) and clears the alignment plate
34
activating pulse.
This control is repeated until the final sheet is aligned, and the alignment plate
34
returns to its home position and stops to complete the alignment of the sheet bundle for the prescribed number of sheets. Operations using the aforementioned paddle
23
and the alignment plate
34
are repeated until the prescribed number of the sheets S has been stacked.
After the alignment operation using the alignment plate
34
has been completed, it checks for the staple operation using the staple unit
3
(S
1406
). Regardless of whether or not there will be a binding operation, the sensor lever
30
and the sheet presence sensor
30
a
detect the presence of the sheets (S
1407
and S
1411
). If no sheet is detected, it sets a waiting pulse to switch the sheet presence sensor
30
a
from no sheet to sheet presence and begins counting down (S
1408
).
If the sheet presence sensor
30
a
continues to detect no sheet until the wait pulse is counted to 0 (S
1409
), it determines that the sheet bundle has been pulled out of the processing tray and stops the finisher apparatus
1
as a sheet pull-out jam (S
1410
) and sends a jam signal to the main apparatus.
When it is confirmed that sheet bundle is to be finished by binding (S
1406
), the sensor lever
30
and the sheet presence sensor
30
a
detect whether or not there are sheets on the processing tray
29
(S
1411
). If there is no sheet, it determines as a pull-out jam as just described (S
1408
, S
1409
, S
1410
) or if there are sheets detected on the processing tray
29
(S
1411
), the sheet bundle on the processing tray
29
is finished by stapling using the staple unit
3
.
In this case, as shown in
FIG. 35
, after setting the startup pulse of the paddle
23
and the startup pulse for the alignment plate
34
to the final sheet, the startup pulse for the staple unit
3
is set (S
1004
).
Then, subsequent to the counting down to 0 for the aforementioned startup pulse (S
1301
and S
1302
), it starts up the staple unit
3
(S
1303
) and sets the startup pulse to activate the staple unit
3
at substantially the same time (S
1304
) to staple using the staple unit
3
. The binding operation using the staple unit
3
continues until the activating pulse set after the aforementioned startup pulse is surpassed is counted down (S
1305
and S
1306
) to 0, and then it stops.
After activating the staple unit
3
in this way to finish the sheet bundle on the processing tray
29
, the timing drive gear
55
is rotated. This rotation moves the elevator lever
64
downward shown in the drawing thereby moving the rotating unit
24
also to the discharge roller
26
side to touch the follower discharge roller
25
inside the rotating unit
24
to the sheet bundle. Along with this, the timing gear
55
rotates the discharge roller
26
via the intermediate gear
56
a
and the transmission gear
56
b
to discharge the sheet bundle to the stacking tray
5
.
The sheets are moved by the paddle
23
, the alignment plate
34
and the staple unit while counting down the operation pulse for the aforementioned paddle
23
or the alignment plate
34
(while aligning) or while operating the staple unit
3
, so that it is impossible for the sensor lever
30
and the sheet presence sensor
30
a
to accurately detect the presence of sheets because it is easy for the sheets to become bent. By controlling the finisher apparatus
1
and the main apparatus
2
according to the inaccurate detection results of the sensor lever
30
and the sheet presence sensor
30
a,
the finisher apparatus
1
and the main apparatus
2
will stop each time it is detected that there is no sheet when moving the sheet using the paddle
23
or the alignment plate
34
or when binding using the staple unit
3
regardless of whether or not there are sheets on the processing tray
29
. There could also be the problem of subsequent sheets being discharged to the processing tray
29
regardless of the sheets being moved by the paddle
23
or the alignment plate
34
or being bound by the staple unit
3
.
Therefore, in the finisher apparatus
1
of the invention, control means in
FIG. 39
controls by ignoring the sheet presence detection results of the sensor lever
30
and the sheet presence sensor
30
a
during the count down of the activating or operation pulse of the aforementioned paddle
23
(S
1404
), the count down of the activating pulse of the alignment plate
34
(S
1405
) or the count down of the activating pulse of the staple unit
3
(S
1412
).
According to this embodiment of the invention, the results of the sheet presence detection by the sensor lever
30
and the sheet presence sensor
30
a
are ignored only while the alignment plate
34
is moving for alignment. However, the time for the series of alignments from the first sheet to the completion of the alignment of the final sheet and the alignment plate
34
returns to its home position is considered as the aligning process time. It is acceptable to ignore the sheet presence detections by the sensor lever
30
and the sheet presence sensor
30
a
during this series of alignment operations or to consider only the time while the alignment plate
34
is actually engaging the sheets as the processing time and to ignore the sheet presence detections by the sensor lever
30
and the sheet presence sensor
30
a
only during those times.
In the same way, according to this embodiment of the invention, only when the paddle
23
feeds the sheet S from the second transport path P
2
to the processing tray
29
along the third transport path P
3
, in other words, while the paddle
23
is rotating in the direction opposing the sheet transport direction (the direction opposing the drive roller
19
), it is considered to be the aligning time and the results of the sheet presence detections by the sensor lever
30
and the sheet presence sensor
30
a
are ignored. However, the time for reverse transport of all sheets from the first sheet to the final sheet by the paddle
23
may be considered as the series of aligning operations and it is acceptable to ignore the sheet presence detection results by the sensor lever
30
and the sheet presence sensor
30
a
during that time.
According to this embodiment of the invention, the control means for ignoring the sheet presence detection results by the sensor lever
30
and the sheet presence sensor
30
a
while counting the activating pulses of the aforementioned paddle
23
, during the counting of the activating pulses of the alignment plate
34
and while counting the activating pulses of the staple unit
3
, is disposed on the finisher apparatus
1
, but it is also perfectly acceptable to employ the control means on the main apparatus side to ignore the aforementioned sheet presence detection results.
Further, according to this embodiment of the instant invention, the finishing apparatus comprising the staple unit
3
is disposed, but it is possible without saying that such unit could also be employed in the apparatuses such as a sorter or discharge tray that do not comprise the staple unit
3
to be suitable for this invention.
The sheet presence sensor that employs the sensor lever is used as the actuator on the finishing apparatus according to this embodiment of the invention, but again, it is perfectly acceptable to have a finishing apparatus that uses an optical sensor that does not use a sensor lever for the embodiment of the instant invention.
The following shall describe the drive transmission to selectively drive the paddle
23
. A lock plate
54
c
that rotates together with the follower gear
54
connected to the paddle drive roller shaft
21
a
to drive the paddle
23
constantly abuts against a reciprocally variable lock pawl
57
by a solenoid
57
b
to stop rotation. In this state, a notched gear
54
b
disposed on the follower gear
54
causes a transmission follower gear
52
to idle. Then, by releasing the engagement of the lock plate
54
c
and a lock pawl
57
by the solenoid drive, the elastic force of a spring
54
d
disposed on the lock plate
54
c
rotates the follower gear
54
which causes the follower gear
54
and the transmission follower gear
52
to mate to rotate the follower gear
54
. One rotation thereof allows the lock plate
54
to engage the lock pawl to stop rotation.
In other words, in a condition that the lock plate
54
c
engages the lock pawl
57
, the drive from the transmission follower gear
52
does not rotate the follower gear
54
because the notched gear
54
b
opposes the transmission follower gear
52
. So the paddle
23
engaging the follower gear
54
is not rotationally driven unless the lock pawl
57
is released from engaging the lock plate
54
c.
Note that it is acceptable to eliminate the stapling process using the staple unit
3
in the aforementioned staple mode, and to discharge the sheets to the stacking tray
5
after only aligning the discharged sheets at the processing tray using the alignment plate
34
and to jog sheets for stacking by shifting them on the stacking tray
5
by alternately discharging the sheets to the stacking tray
5
in the aforementioned pass-through mode.
The jog process is acceptable for one sheet aligned by the alignment plate
34
discharged to the processing tray
29
. In that case, the alignment plate
34
aligns the sheet from the aforementioned prescribed home position and returns to its prescribed home position to stop.
In this jog process, it is possible to apply the control means for ignoring the detection results of the sensor lever
30
and the sheet presence sensor
30
a
while aligning the aforementioned paddle
23
and the alignment plate
34
.
Therefore, in the pass-through mode, the paddle
23
is stopped without releasing the engagement of the lock plate
54
c
and the lock pawl
57
to lower the rotating unit
24
and discharge the sheet S to the stacking tray
5
. In the staple mode, when the trailing edge of the sheet S passes the endless belt drive roller
19
and the follower roller
17
, the lock pawl
57
is released from the lock plate
54
c
to rotate the paddle
23
to enable feeding the sheet S into the processing tray
29
.
The following will describe the timing drive gear
55
that operates the elevator lever
64
used in raising and lowering the rotating unit
24
.
This timing drive gear
55
is equipped with a locking pawl
60
disposed on one side in
FIG. 9
of the timing drive gear
55
to constantly engage the reciprocally variable lock pawl
59
by the solenoid
59
a
to stop the rotation of the timing drive gear
55
, a wheel
61
to rotate the timing drive gear
55
in the counter-clockwise direction when the engagement of the lock pawl
59
and locking pawl
60
is released, notched gears
62
and
63
that idle the rotating unit
24
and the follower roller drive transmission gear
56
a,
and a cam
65
that reciprocates along the shaft direction of the elevator lever
64
and engages the leading edge
64
a
on the elevator lever
64
which is disposed on the other side of the timing drive gear
55
to rotate the rotating unit
24
. On the elevator lever
64
, a leading edge
64
a
is constantly urged to the elastic contact direction of the cam
65
by a spring
66
, and in the initial state, the engagement of the leading edge
64
a
and the oblong hole
68
allows the leading edge
64
a
to separate from the cam
65
.
Next, explanation will be made for the operation of the timing drive gears according to FIG.
11
(A) to FIG.
12
(B) as an example of finishing the sheet S. As described above, the processing mode for the sheet S comprises the staple mode and the pass-through mode. The method used to feed the sheet S varies according to the mode, so in the following, the staple mode is first described.
In the staple mode, stapling is made as a post processing for finishing the sheet bundle, and the number of originals processed on the image forming apparatus unit G is counted when reading images. The binding process occurs based upon the count and the number of created sheet bundle. These bound sheet bundle is then stacked in this mode.
In other words, when a first sheet in one unit or bundle is supplied to the inlet
7
, the sheet inlet sensor
11
disposed between the inlet
7
and the transport roller
15
detects the sheet. Based on the detection result of this sensor, the drive motor
43
begins to drive thereby rotating the rotating belt
48
which in turn rotates the transport roller
15
, the discharge roller
28
and the endless transport belt drive roller
19
.
At this time, the transmission follower gear
52
also rotates, but the follower gear
54
is opposed to the notched gear
54
b
so that drive is not transmitted and it stops rotating. Furthermore, as shown in FIG.
11
(A), the follower transmission gear
53
also rotates, but the notched gear
62
on the timing drive gear
55
opposes the follower transmission gear
53
so the lock pawl
59
and the abutting portion
60
engage to stop the rotation of the timing drive gear
55
and the discharge drive transmission gear
56
a.
Also, the sheet S is transported toward the level of the first transport path P
1
in the transport guide
8
by the cooperation of the follower roller
14
and transport roller
15
, and the cooperation of the follower roller
17
and the endless transport belts
18
. When the sheet inlet sensor
11
detects the trailing edge of the sheet S in the direction of transport thereof, after a prescribed amount of time has passed, when the leading edge of the sheet S is positioned from the discharge outlet
10
onto the stacking tray
5
, the trailing edge of the sheet S exits from between the follower roller
17
and the endless transport belts
18
wherein it faces the direction of the third transport path P
3
by the drop portions
18
b
on the endless transport belts
18
.
In this state, to permit the rotation of the paddle
23
, the solenoid
57
b
activates to release the engagement of the lock plate
54
c
on the follower gear
54
and the lock pawl
57
. The rotation of the follower gear
54
begins by the spring
54
d.
In association with this rotation, the follower gear
54
and the transmission follower gear
52
mesh to rotate the follower gear
54
, which is disposed on the paddle drive roller shaft
19
a
thereby rotating the paddle
23
.
This paddle
23
returns the sheet S in the direction opposing the direction of transport fed up to that point and feeds it to the sheet stacking portion
29
a
and the endless transport belts
18
. The edge of the sheet S then touches the sheet leading restricting portion
29
b
on the processing tray
29
.
Then, the alignment plate drive motor
36
drives to move the alignment plate
34
to align the sheet S by touching it against the main apparatus side frame
2
a
to which the staple unit
3
is mounted in a position opposing the direction of travel of the alignment plate
34
.
At that point, the operations describe above are performed for each sheet S transport. When the prescribed number of sheets has been stacked, the staple unit
3
drives to bind the sheet S with the staple.
When the staple binding operation is executed, to allow the rotation of the timing drive gear
55
, the timing solenoid
59
a
activates, as shown in FIG.
11
(B), to release the engagement of the lock pawl
59
and the abutting portion
60
on the timing drive gear
55
and the timing drive gear
55
is rotated in the counter-clockwise direction by the weight of the wheel
61
.
This rotation causes the follower transmission gear
53
to separate from the notched gear
62
and to mesh with the timing drive gear
55
. Drive from the follower transmission gear
53
is received to start rotating the timing drive gear
55
.
Then, as can be seen in FIG.
11
(C), the leading edge cam follower portion
64
a
on the elevator lever
64
positioned on the back side of the timing drive gear
55
resists the urging force in the upward direction of the drawing of the spring
66
by the shape of the cam, in elastic contact with the timing drive gear
55
and the cam portion
65
to start the downward direction movement of the elevator lever
64
in the drawing. By the elevator lever
64
moving downward, the elevator pin
64
b
engages the slit
24
c
on the rotating unit
24
and also lowers thereby starting the downward movement of the rotating unit
24
in the drawing. In FIG.
11
(A) to FIG.
12
(B), the slit
24
c
on the rotating unit and the elevator pin
64
b
are positioned on the back side of the elevator lever
64
, but in these drawings they are shown as solid lines for explanatory purposes.
After the rotating unit
24
starts its downward movement, the discharge roller drive transmission gear
56
a
separates from the notched gear
63
on the timing drive gear
55
and meshes the timing drive gear
55
to start rotating the discharge roller drive transmission gears
56
a
and
56
b,
thereby starting the rotation of the discharge roller
26
.
Next, as shown in FIG.
12
(A), when the leading edge
64
a
on the elevator lever
64
elastically contacts the outermost circumference of the cam portion
65
having a diameter substantially equivalent to the timing drive gear
55
, the discharge roller
26
and the follower roller
25
on the leading edge side of the rotating unit
24
nip the sheet S bundle and bind them, subsequently discharging the sheet bundle to the stacking tray
5
. The completion of the discharging of the sheet S is detected by the sheet presence sensor
30
a
for detecting the upward return of the sensor lever
30
which is positioned at the leading edge of the processing tray
29
shown in FIG.
2
and FIG.
3
.
When the sheet S bundle is discharged to the stacking tray
5
after binding, the elastic contact of the leading edge
64
a
on the elevator lever
64
and the cam portion
65
is released, as shown in FIG.
12
(B), and the rotating unit
24
begins rotating in the upward origin direction. After the follower roller
25
separates from the discharge roller
26
, the notched gears
62
and
63
on the timing drive gear
55
move to a position that resists the intermediate gear
56
a
that transmits drive force to the transmission follower gear
53
and the discharge roller
26
and return to their original positions, as shown in the status of FIG.
11
(A).
The explanation will be made for the pass-through mode. This mode transfers the sheet S discharged from the image forming apparatus G directly into the stacking tray
5
from the first transport path P
1
via the second transport path P
2
and the sheet S is not bound using the staple unit. This mode is applied to stack large quantities of the sheet S. The operational differences of this mode and the staple mode are that the paddle
23
is not constantly rotated and the starting of the rotation of the timing drive gear
55
is early in accordance with the timing of the transport of the sheets.
In other words, when the sheet S is supplied to the inlet
7
, the sheet inlet sensor
11
disposed between the inlet
7
and the transport roller
15
detects the sheet. Based on the detection result of this sensor, the drive motor
43
begins to drive thereby rotating the rotating belt
48
which in turn rotates the transport roller
15
, the discharge roller
28
and the endless transport belt drive roller
19
.
At this time, as shown in FIG.
11
(A), the follower transmission gear
53
also rotates, but the notched gear
62
on the timing drive gear
55
opposes the follower transmission gear
53
, so that the lock pawl
59
and the abutting portion
60
engage to stop the rotation of the timing drive gear
55
and the discharge drive transmission gear
56
a.
After the sheet inlet sensor
11
detects the leading edge of the sheet S, for a slight delay, to permit the rotation of the timing drive gear
55
, the timing solenoid
59
a
activates, as shown in FIG.
11
(B), to release the engagement of the lock pawl
59
and the abutting portion
60
on the timing drive gear
55
, and the timing drive gear
55
is rotated in the counter-clockwise direction by the weight of the wheel
61
.
This rotation causes the follower transmission gear
53
to separate from the notched gear
62
and to mesh with the timing drive gear
55
. Drive from the follower transmission gear
53
is received to start rotating the timing drive gear
55
. The operations after that are performed in the same manner as those in the staple mode from FIG.
11
(C) to FIG.
12
(B). Therefore, the rotating unit
24
operates up and down for each time the sheet S is transported into the main apparatus
2
and is discharged to the stacking tray
5
. The completion of the discharging of the sheet S is detected by the sheet presence sensor
30
a
detecting the resetting of the sensor lever
30
which is positioned at the leading edge of the processing tray
29
shown in FIG.
2
and FIG.
3
.
Note that because the paddle
23
is not rotated, the solenoid
57
b
does not activate when executing the pass-through mode, and the lock plate
54
c
on the follower gear
54
and the lock pawl
57
are in the engaging state.
Finally, the escape mode discharges a special sheet, such as non-standard size sheet, to the escape tray
6
. The rotating flapper
16
is rotated counter-clockwise from the state shown in FIG.
2
and
FIG. 3
to transport the sheet S from the first transport path P
1
to the fourth transport path P
4
and to the escape tray
6
by the second discharge roller
28
.
In this case, the escape mode is preset to rotate the flapper
16
to be positioned to guide the sheet S into the fourth transport path P
4
. In this state, the sheet inlet sensor
11
detects the sheet S when it is supplied from the inlet
7
and the drive motor
43
starts driving. The result is that the transport roller
15
and the second discharge roller
28
are drivingly rotated to discharge the sheet S to the escape tray
6
.
Since the rotations of the paddle
23
and the timing drive gear
55
are unnecessary, the solenoid
59
a
that permits the rotation of the paddle
23
and the timing drive gear
55
is not activated.
In these operations, the sheet S is discharged from the discharge outlet
10
on the main apparatus
2
, but in the following, explanation is made for the stacking tray
5
that stacks the discharged sheet S.
As can be seen in FIG.
13
(A) and FIG.
13
(B), the stacking tray
5
includes a base
69
having a mounting portion
69
a
detachable to the main apparatus
2
, a sheet storage portion
71
held to move up and down via an elevator control unit
70
to the base
69
, and a support bracket
72
fastened to the bottom of the sheet storage portion
71
. The support bracket is fastened to the top of a movable gear
74
.
The elevator control unit
70
is equipped with a cylindrical fastening gear
73
fastened to the base
69
, the movable circular arc gear
74
fastened to the support bracket
72
, a planetary gear
75
that meshes the gears
73
and
74
to displace, a shaft arm
76
that is connected to the gears
73
and
74
and the planetary gear
75
for fixing each of the relative distances, and a coil spring
77
that constantly urges the sheet storage portion
71
upward and disposed between the top surface of the base
69
and the bottom surface of the support bracket
72
.
There are two coil springs
77
disposed to sandwich the gears
73
and
74
and the gear
75
. They displace the sheet storage portion
71
according to the weight of the sheet S stacked sequentially on the top of the sheet storage portion
71
. The spring constant is set so that it is possible to sequentially stack the subsequent sheets on top of the sheet S to have substantially a constant height.
When the sheet storage portion
71
that is the support surface for the sheets is displaced downward in resistance to the urging forces of the coil springs
77
, the upper surface of the sheet storage portion
71
mounted via the support bracket
72
on the upper surface of the movable gear
74
moves in a parallel state from the upper position shown in FIG.
13
(A) downward to the lower position shown in FIG.
13
(B) as the weight of the sheets S increases. Therefore, the sheet storage portion
71
lowers according to the weight of the stacked sheets while the upper surface of the sheet storage portion
71
and the sheet restricting surface
2
c
that restricts the edges of the stacked sheets, disposed on the front of the main apparatus
2
, constantly maintain substantially the same state without large variations in the angle created, thereby enabling a substantially constant height distance between the stacked sheet upper surface and the discharge roller
26
.
The upper surface of the sheet storage portion
71
is made to allow the sheets that are stacked thereupon to slide under their own weight. Furthermore, it is formed to have an angle from the sheet restricting surface
2
c
on the main apparatus
2
to gradually increase toward the upstream direction in the sheet discharge direction. Still further, the degree of the angle near the sheet restricting surface
2
c
is set to be different from the angle at the upstream side thereof.
In other words, the angle created by a line SP extending in the direction of the discharge of the sheet that is restricted by the discharge roller
26
and the discharge follower roller, and the upper surface of the sheet storage portion
71
a
forming the upper surface support portion of the first support surface
71
a
, has a relatively small angle α and the second support surface
71
b
on the sheet restricting surface side is set with the angle β which is larger than the angle α.
Therefore, the level for the sheet restricting surface
2
c
is set to be large with respect to the discharge roller
26
, so even if the trailing edge of the sheet that is stacked on the sheet storage portion (the edge of the sheet restricting surface) curls upward, in the drawing, the edges of the subsequently discharged sheet S will have less chance to touch the trailing edge of the previously discharged sheet and thereby preventing the leading edge of the sheet S to be caught to the curled sheet that was discharged.
Note that according to the test, when using the copy sheet used in a conventional apparatus, it is preferred that the angle α formed by the aforementioned line SP extending in the direction of sheet transport and the upper surface of the sheet storage portion
71
be within a range of 15° to 23° and more than 25° for the larger angle β. However, these angles vary according to the thickness and material quality of the sheet used and are not particularly limited to these angle values. If necessary, it is also perfectly acceptable to make the angle a larger than the angle of β.
The drawing shows the second support surface
71
b
that is angled and connected continuously to the first support surface
71
a
via a bend portion
71
c,
but it is also possible to eliminate the levels, i.e. step, and to connect the first support surface
71
a
and the second support surface
71
b
to gradually change the angle of the bend portion
71
c
in a circular arc surface. In other words, it is acceptable to have a large level between the discharge outlet
10
and the second support surface
71
b,
rather than simply extending the upper surface of the first support surface
71
a
to the sheet restricting surface
2
c.
Furthermore, the apparatus of the present embodiment alleviates the problems of upward and downward curls when overlapping the sheet over the processing tray
29
and the aforementioned sheet storage portion
71
, because the leading edge of the sheet on the sheet storage portion side is set to be positioned further upstream in the sheet discharge direction than the aforementioned bend portion
71
c
even when using the minimum size of sheet that can be stacked.
Also, the staple unit side on the second support surface
71
b
is disposed with a notched portion
71
d
as can be seen in FIG.
1
. This notched portion
71
d
is to prevent the stapled side of the sheet bundles from rising due to the size of the staples, even when the sheet bundles that have been stapled are stacked.
As shown in FIG.
2
and
FIG. 3
, the sheet holding lever
78
to push the trailing edge of the sheet S (the edge by the sheet restricting surface
2
c
) from above the second support surface
71
b
on the sheet storage portion
71
is made to appear from the sheet restricting surface
2
c.
Therefore, even if a large curl is formed in the sheet S on the second support surface, it will securely stack on the sheet storage portion
71
.
The sheet holding lever
78
rotates by using a rotating shaft
82
as the shaft pivot. When a sheet stack volume detection sensor
85
is detecting the lever end on the sheet holding lever
78
while it is holding the sheet, it determines that it is positioned at the lower limit of the sheet storage portion
71
and outputs a stop signal to the image forming apparatus G.
The following describes the sheet S stacking operation when discharged from the main apparatus
2
according to FIGS.
14
(A) to
15
(B).
Initially, the first sheet S
1
discharged, shown in FIG.
14
(A), is stacked on the upper surface of the sheet storage portion
71
and the end thereof is pressed by the sheet holding lever
78
onto the second support surface
71
b.
Subsequently, the sheet S
2
is transported along the second transport path P
2
to be discharged along the discharge path by the discharge roller
26
. The sheet S
2
is discharged along the line SP extending in the direction of the discharge of the sheet, but this line SP traverses the first sheet support surface of the sheet storage portion
71
, the angle thereof being set to the comparatively smaller angle α. Therefore, even if the leading edge of the sheet S
2
curls downward, this angle is smaller, so that the leading edge of the sheet S is not transported with its bend toward the second sheet support surface but is guided downstream in the sheet discharge direction along the first support surface
71
a.
Also, because the trailing edge of the initially stacked sheet S is being held to the second support surface
71
b
by the sheet holding lever
78
, the sheet S will not be moved by the sheet S
2
.
FIG.
14
(B) shows the trailing edge of the sheet S passing through the sensor lever
30
. After a prescribed small amount of time since the passing signal, the trailing edge of the sheet S
2
is discharged from the discharge roller
26
and it begins to fall toward the second support surface
71
b.
At substantially the same time as the discharge, the pressing solenoid
83
shown in
FIG. 2
activates for retracting the sheet holding lever
78
into the sheet restricting surface
2
c
as shown by the direction of the arrow in
FIG. 14
(B).
After retracting, the sheet S
2
falls toward the second support surface
71
b,
as can be seen in FIG.
15
(A), but there is a delay in the falling time and the lever solenoid is deactivated with the delay. This deactivation returns the sheet holding lever
78
by the spring
84
to move toward the second support surface in the direction of the arrow in the drawing. Then, in the state shown by FIG.
15
(B), it presses the edge at the sheet restricting surface
2
c,
i.e. the trailing edges of the sheet S
1
and sheet S
2
.
Because, as described above, the angle α formed by the line extending in the direction of sheet discharge for the sheet S and the first support surface is smaller than the angle β formed by the second support surface on the sheet restricting surface
2
c
side, it is possible to make a long distance between the discharge roller
26
and the second support surface and push the sheets from above, so that the stacked sheets do not jam and the stacking performance is improved.
Also, when discharging the bundles of the sheets S, the same operations are performed as in the single sheet, so in this case, the stacking performance for the sheet bundles is also improved. As the volume of the sheets S stacked upon the stacking tray
5
increases, the coil springs
77
compress to allow the stacking tray
5
to maintain substantially a constant height for the uppermost sheet of the sheets S.
Then, when the sheet is straddling between the stacking tray
5
and the processing tray
29
, the sheet is shifted in the width direction by the aligning plate, but because the sheets in the stacking tray
5
are held by the sheet holding lever
78
, there is no disturbance to the alignment of the sheets already stacked in that tray.
Note that in the explanation above for the present embodiment, the sheet holding lever
78
is disposed to be moved by the solenoid as the sheet holding means. However, it is acceptable to rotationally drive, by a motor or another source of force not shown in the drawings, a holding paddle roller
86
mounted with an elastic side composed of rubber, etc, as shown in the
FIG. 16
, to appear from the side of the sheet restricting surface
2
c
in correspondence to the sheet discharge timing. Also, as shown in
FIG. 17
, it is acceptable to hold the sheet with a structure such that an end of a sheet holding lever
87
is mounted to a cam plate
88
rotated by a motor, not shown in the drawing, and is linked by a fixed pin
89
into a slit on the sheet holding lever
87
.
In other words, it is acceptable for any means to hold the sheet end by retracting only at the time of the discharge of the sheet S from the discharge roller
26
.
The explanation above describes the first embodiment according to
FIG. 1
to FIG.
17
. The following describes the second embodiment according to
FIG. 18
to FIG.
24
. However, the portions of this second embodiment are the same as those of the first embodiment and have the same numbers, and the description thereof will be omitted.
The differences between the first and second embodiments of the invention are described in general according to FIG.
18
.
Firstly, the escape tray
6
that stores the special sized sheet positioned above the stacking tray
5
and the fourth transport path P
4
are eliminated. Therefore, the special sheet is discharged from the image forming apparatus in advance, to make the finisher apparatus
1
as the sheet stacking apparatus more compact.
Secondly, in the first embodiment, the sheet stacking portion side (
18
c
) of the endless transport belts
18
which transports the sheet S into the processing tray
29
along the third transport path P
3
is free, but in the second type of apparatus, it is supported by a follower pulley on the sheet stacking portion side (
18
c
).
Thirdly, the elevator drive of the sheet storage portion
71
on the stacking tray
5
is provided with the coil springs
77
, but the aforementioned elevator drive is provided with a motor in this embodiment and it detects the uppermost surface of the sheet stacked upon the sheet storage portion
71
, the raising and lowering the sheet storage portion
71
being made by the signal therefrom. Also, a self-weighted flapper
130
is disposed on the same shaft as the discharge follower roller
25
on the rotating unit
24
, so that the sheet discharged from the discharge roller
26
is quickly dropped into the sheet storage portion.
Next, each of the aforementioned points will be explained. The apparatus of the second embodiment shown in FIG.
18
and
FIG. 19
is equipped with a feed belt unit
100
having the endless transport belts
18
as the sheet feeding means to transfer the sheet S into the processing tray
29
along the third transport path P
3
. The feed belt unit
100
, including an explanation of
FIG. 20
, is composed of drive pulleys
101
that rotate along with the drive shaft mounted to the belt drive shaft
19
a,
follower support pulleys
102
positioned on the sheet stacking surface
29
a
having a predetermined gap with the drive pulley
101
, support plates
104
mounted to both sides of the pulleys to maintain the gap between the drive pulley
101
and the follower support pulley
102
, and the endless transport belts
18
each being disposed between the drive pulley
101
and the follower support pulley
102
. The support plate
104
rotationally supports the rotating shaft
103
on the follower support pulley
102
.
Therefore, when the belt drive shaft
19
a
is drivingly rotated, the drive pulleys
101
fastened to this shaft
19
a
also rotate, and the endless transport belts
18
and follower support pulleys
102
move while rotating.
The support plate
104
comprises an up-side-down U-shaped mounting portion
106
. Because the mounting portion is fastened to the belt drive shaft
19
a,
the support plate
104
comprising the follower support pulley
102
is swingably supported by using the belt drive shaft
19
a
as its shaft pivot. Furthermore, the support plate
104
is mounted with a weight balance
105
on the side opposing the follower support pulley
102
, as can be seen in FIG.
20
. This weight balance causes the sheet drawing portion
18
c
on the endless transport belt
18
on the follower support pulley
102
side to touch the sheet S with substantially a constant touching force.
Since the structure above employs the drawing unit
100
, the sheet drawing portion
18
c
which is the portion contacting the uppermost sheet on the endless transport belt
18
is lifted according to the sheet thickness when there are many sheets stacked on the processing tray
29
. In other words, the support plate
104
swings around the belt drive shaft
19
a.
The direction of the swing is opposite to the direction of the rotation A of the belt drive shaft
19
a.
Because the aforementioned endless transport belts
18
are backed up by the follower support pulleys
102
, it swings according to the number of sheets on the sheet stacking portion
29
a
on the processing tray
29
, but as the number of the sheets on the processing tray
11
increases, the area of contact on the sheet S will not vary. In other words, there is no variation in the transporting force depending on the number of the sheets S stacked. For that reason, even if the number of the sheets stacked upon the sheet stacking portion
29
a
increases, it does not press further the sheet S that strikes the sheet leading restricting portion
29
b,
thereby not bending the sheet S.
Also, in the same way as the endless transport belt
18
in the first embodiment of the invention, the sheet drawing portion
18
c
on the endless transport belt
18
is arranged to a position that overlaps the alignment plate
34
. Because it is backed up by the follower support pulley
102
, it is possible to accurately align the sheet S even when moving the sheet S in the width direction using the alignment plate
34
.
Furthermore, the feed belt unit
100
has the weight balances
105
, but it is possible to adjust the pressing force against the sheet S on The endless transport belts
18
by adjusting the moments of rotation by the weight balances
105
.
However, if the weight of the support plate
104
is small, the weight balance
105
is unnecessary. Also, instead of the aforementioned weight balance
105
, it is acceptable to use a spring member or the like to adjust the pressing force.
Furthermore, as illustrated in
FIG. 21
, it is acceptable to omit the structure for the support plate
104
on the feed belt unit
100
and to rotationally support a follower support pulley
107
on a wire-shaped support arm
108
and hang the up-side-down U-shaped swinging end on the side opposing this follower support pulley
107
to the belt drive shaft
19
a.
Because there is the possibility of the leading edge of the sheet striking the sheet stacking portion
29
a
on the processing tray
29
or the sheet on the sheet stacking portion
29
a,
to be bent when the sheet is discharged to the processing tray
29
while the support plate
104
swings around the belt drive shaft
19
a
and the endless transport belts
18
are in the state shown in FIG.
18
and FIG.
30
(D), it is possible to have the angle of discharge of the endless transport belts
18
facing further upward than the state shown in FIG.
18
and FIG.
30
(D) to prevent the leading edge of the sheet from ramming into the processing tray
29
when starting to discharge the sheet to the processing tray
29
as is illustrated for example in FIG.
30
(A) to FIG.
30
(C). Later, at a prescribed timing, such as the exiting of the trailing edge of the sheet from the endless transport belts
18
, the endless transport belts
18
move to a downward position shown in FIG.
18
and FIG.
30
(D). By facing the angle of discharge lower than that when starting to discharge the sheet to the processing tray
29
, the sheet drawing portions
18
c
on the endless transport belts
18
can move the sheet to the sheet leading edge restricting member
29
b
for alignment.
Specifically, it is acceptable (1) that the support plate
104
whose position is generally determined by a spring member, not shown in the drawings, at the upward position shown in FIG.
30
(A), is moved by drive means, such as a solenoid, also not shown in the drawings, to a downward position as depicted in FIG.
18
and FIG.
30
(D) to thereby move the endless transport belts
18
. Conversely, it is acceptable (2) that the support plate
104
whose positioning is generally determined by a spring, not shown in the drawing, at the downward position shown in FIG.
18
and FIG.
30
(D), is moved by drive means, such as a solenoid, also not shown in the drawings, to an upward position as depicted in FIG.
30
(A) to thereby move the endless transport belts
18
.
In this case, to move the endless transport belts
18
, as a timing control to switch the swinging of the support plate
104
, in the example (1), the solenoid is activated based upon the detection after a prescribed number of pulses or a prescribed amount time from when the sheet inlet sensor
11
detects the leading edge of the sheet until before the trailing edge of the sheet is completely discharged from the processing tray
29
. In the case of (2), it is conceivable to have a control to switch the activation of the solenoid based upon the detection of a prescribed number of pulses or a prescribed amount of time from when the sheet inlet sensor
11
detects the leading edge of the sheet until the trailing edge of the sheet is completely discharged from the processing tray
29
.
These control means can be formed on either the image forming apparatus G or the sheet finishing apparatus
1
.
Thus, as described above, it is possible to accurately finish processes including binding with a staple on a sheet bundle because the endless transport belts
18
are moved to the downward position shown in FIG.
18
and FIG.
30
(D) from the upward position when starting to discharge the sheets to the processing tray
29
, and by using the sheet feeding portions
18
c
on the endless transport belts
18
to move the sheets to the sheet leading restricting portion
29
b,
then aligning the sheets in the direction traversing the direction of discharge to the processing tray
29
or stapling the aligned sheets using the staple unit
3
shown in FIG.
19
and maintaining the optimum attitude of the sheet bundle for binding at the downward position of the endless transport belts
18
.
Note that according to this embodiment of the invention, when the sheets are discharged to the processing tray
29
and aligned by the sheet leading restricting portion
29
b,
they are moved in the direction opposite of the direction of transport to the processing tray
29
by the sheet drawing portions
18
c
on the endless transport belts
18
. However, as shown in FIGS.
30
(A) and
30
(B), it is acceptable to form the sheet leading restricting portion
29
b
in the downstream side in the direction of sheet discharge to the processing tray and to move the sheet to the processing tray
29
in the same direction as the direction of sheet transport by the sheet drawing portions
18
c
on the endless transport belts
18
.
In this case, as can be seen in FIG.
30
(A) to FIG.
30
(C), after the sheet has been completely discharged to the processing tray
29
, the endless transport belts
18
, while they continue their driving in the direction of transport to the processing tray or stops their driving, move to the downward position for the discharge, and in order to move the sheet to the sheet leading restricting portion
29
b,
drive in the opposite direction to that of the drive in the direction of sheet discharge to the processing tray, as can be seen in FIG.
30
(D). As an example of the timing to switch the up and down movements or to cut the drive to the endless transport belts
18
, the sheet inlet sensor
11
detects the number of pulses or a predetermined time necessary to discharge the sheet from detecting the sheet trailing edge to the complete discharge thereof, and the endless belt is moved by a solenoid, not shown in the drawings, downward and to reverse the drive thereto.
The following describes the second type of the stacking tray
5
according to FIG.
22
. This stacking tray
5
employs a motor unit
120
that comprises a motor as the elevator mechanism of the sheet storage portion
71
. The motor unit
120
is mounted to a shaft arm
76
that supports the moving gear
74
and the planetary gear
75
and connects a motor shaft
121
from the motor unit
120
to the planetary gear
75
. This motor rotates the motor shaft
121
in the clockwise direction to raise the sheet storage portion
71
and in the counter-clockwise direction to lower the sheet storage portion
71
. Therefore, the uppermost surface of the sheet stacked on the sheet storage portion
71
is detected. That signal is sent to the motor unit
120
whereby the motor is controlled to run in forward or reverse to enable a constant and accurate sheet surface level.
The aforementioned sheet surface level detection mechanism, shown in
FIG. 23
, detects the level by using the sheet holding lever
78
that rotates around a shaft pivot
81
and transmissive type sensors
125
a
and
125
b
for detecting a detection flag
124
formed with the sheet holding lever
78
as one unit. The detection flag
124
comprises a first flag portion
124
a
and a second flag portion
124
b
and is equipped, between these flags, with a notch portion
124
c
that does not affect the sensor.
FIGS.
23
(A) and
23
(B) depict the sheet holding lever in the position to appropriately hold the sheet S wherein the first sensor
125
a
is interrupted by the first flag portion
124
a
to turn it ON. On the other hand, the second sensor
125
b
is not detecting the second flag portion
124
b
and is therefore OFF. This is the position where the sheet storage portion
71
on the stacking tray
5
is set to the appropriate position. As the sheet S is discharged sequentially to the sheet storage portion
71
, the sheet holding lever
78
reciprocates in the positions of the dotted and solid lines shown in FIGS.
23
(A) and
23
(B). Each time the sheet S is stacked onto the sheet storage portion, the detection flag moves in the clockwise direction and the second flag portion
124
b
is detected by the second sensor
125
b
and turns ON while the other first flag portion
124
a
is detected by the first sensor
125
a
and is turned ON. When both the first sensor
125
a
and the second sensor
125
b
ON output the signals, it outputs a signal to the stacking tray
5
to lower the sheet storage portion
71
. This signal causes the motor drive shaft
121
to rotate in the counter-clockwise direction to lower the sheet storage portion
71
for a prescribed amount.
This positions the uppermost surface of the sheet S stacked on the sheet storage portion
71
at a constant height.
Note that the aforementioned sheet storage portion
71
does not move up or down each time a conventional sheet is discharged, but it is made to lower the position when the uppermost surface of the sheets exceeds a prescribed height, so that this alleviates the complexities of actions each time a sheet is discharged.
Furthermore, when the notched portion
124
c
is positioned at the first sensor
125
a
to turn it OFF and the second sensor
125
b
OFF, it is determined that the sheet storage portion
71
is in a position lower than the prescribed height and it is to be raised. When the first sensor
124
a
is OFF and the second sensor is ON, the sheet holding lever
78
is determined to be retracted into the sheet restricting surface
2
c.
Also, when the sheet storage portion
71
is positioned in the downward position and the first sensor
124
a
and the second sensor
124
b
are both ON, it is determined that the sheet storage portion
71
is full of sheets and it stops the stacking operation on the sheet stacker.
This describes the configuration for detecting the sheet surface level on the stacking tray
5
. However, the second type of apparatus is equipped with a sheet flapper
130
rotatably mounted to a support shaft
131
on the follower discharge roller
25
maintained by the rotating unit
24
to accurately stack the sheets to this stacking tray, as can be seen in FIG.
18
.
This sheet flapper
130
moves up and down according to the discharge of the sheet to securely drop the trailing edge of the sheet S into the sheet storage portion.
The action of the sheet flapper
130
is described in accordance with FIGS.
24
(A) and
24
(B). The actions and operations of the sheet holding lever
78
to hold the sheet on the sheet storage portion
71
are the same as those described in FIGS.
14
(A) to
15
(B), so the following description is focused on the sheet flapper
130
for dropping the sheet S, which is discharged in cooperation with the sheet holding lever
78
, onto the sheet storage portion
71
.
FIG.
24
(A) depicts the rotating unit
24
positioned downward and the sheet S is discharged by the discharge roller
26
and the follower discharge roller
25
along the sheet discharge direction line extension SP. In this state, the sheet flapper
130
is simply hanging downward on a support shaft
131
on the follower discharge roller
25
, so that the sheet is firmly held because of the sheet being nipped by the discharge roller
26
and the follower discharge roller
25
, thereby lifting the sheet flapper while being discharged. This state continues until the trailing edge of the sheet S
2
separates from the nip of the discharge roller
26
and the follower discharge roller
25
.
When the trailing edge of the sheet S
2
separates from the nipping by the discharge roller
26
and the follower discharge roller
25
, the trailing edge of the sheet S is pushed down along the sheet restricting surface
2
c
by the weight of the sheet flapper
130
, as is depicted in FIG.
24
(B). Simultaneously with the falling of the sheet, the sheet holding lever
78
rotates clockwise in the direction of the arrow in the drawing to push the trailing edge of the sheet S
2
onto the sheet storage portion
71
. Therefore, even if the trailing edge of the sheet S has a large curl upward toward the discharge roller, it is fixed by the downward rotation of the sheet flapper under its own weight to alleviate the problem of the leading edge of subsequently discharged sheet S from striking the curl and cause a jam.
The positional relationships of the sheet holding levers
78
and the sheet flappers
130
in the width direction (the direction traversing the direction of sheet transport) are made to have the sheet holding levers
78
located in three positions (see
FIG. 1
) and to arrange a plurality of the sheet flappers therebetween (two in this embodiment) to avoid collisions between the sheet holding levers
78
and the sheet flappers
130
. Furthermore, the sheet flapper
130
according to this embodiment is to rotate or move the sheet flapper
130
to push the trailing edge of the sheet S under its own weight, but it is also perfectly acceptable to drive the flapper up and down using drive means, such as a solenoid, operated at a timing of the discharge of the sheet S.
The following explains the embodiment that improves the second type. In the improved embodiment of the second type, each sheet that passes through the follower roller
17
and the drive pulley
101
receives the force of transport by the follower discharge roller
25
and the discharge roller
26
when being discharged directly to the sheet storage portion
71
. However, in other cases, as can be seen in FIG.
30
(A) to FIG.
30
(D), each sheet that passes through the follower roller
17
and the drive pulley
101
receives the load of a weight member
201
and is transported and discharged into the downstream processing tray
29
by the endless transport belts
18
while being pushed by that belts.
In this way, the weight member
201
which presses each sheet to the endless transport belts
18
is swingably supported by a support shaft
203
located above the endless transport belts
18
, as can be seen in FIG.
30
(D), FIG.
28
and FIG.
29
. It is arranged in a position closer to the sensor lever
30
(the sheet presence sensor
30
a
) than the endless transport belts
18
in the direction traversing the direction of sheet transport and discharge (the sheet width direction) toward the downstream processing tray
29
.
Note that the sheets are moved to the sheet leading restricting portion
29
b
by the sheet drawing portions
18
c
and that there are oblique grooves in the aligning direction, shown in FIG.
28
and
FIG. 29
on the surface of the endless transport belts
18
for aligning the sheets in the sheet transport and discharge directions. These grooves act to move the sheet in a direction traversing the direction of sheet transport and discharge (the sheet width direction) to align the sheet along with the rotation of the endless transport belts
18
.
So, by arranging the weight member
201
in a position nearer the sensor lever
30
(sheet presence sensor
30
a
) than the endless transport belts
18
and preventing the bending of the sheet near the sensor lever
30
, when the sheet is transported and discharged to the processing tray
29
, or aligned by the alignment plate
34
on the processing tray
29
, it operates to align in the sheet width direction.
The Sheet is pushed securely toward the sensor lever
30
to be securely detected which results in alleviating the problem of the sheet from subsequent job after being discharged regardless of whether there is still a sheet on the processing tray
29
.
Setting the sensor lever
30
and the weight member
201
to positions separated in the direction of sheet transport and discharge may not provide the effect of holding the bend in the sheet by the weight member
201
up to the sheet at the sensor lever
30
position, so that the weight member
201
and the sensor lever
30
are positioned to overlap each other at least in the direction of sheet transport and discharge, as shown in
FIG. 29
, to securely allow the weight member
201
to hold the sheet at the sensor lever
30
position.
Furthermore, by positioning the endless transport belts
18
, the weight member
201
and the sensor lever
30
to overlap at least each other in the direction of the sheet transport and discharge, the space is saved to enable the apparatus itself to be more compact.
Note that as sheet presence detection means, an optical type, other than the lever type used above, can be used in the aforementioned invention.
As shown in FIG.
30
(A), the weight member
201
comprises a pressing portion
201
a
that contacts the upper surface of the sheet when the sheet is being pushed to the endless transport belts
18
under its own weight when it is nipped with the endless transport belts
18
, and a pressing portion
201
b
located further downstream in the direction of transport than the pressing portion
201
a,
to press the trailing edge of the sheet by the swinging of the weight member
201
around the shaft
203
after the trailing edge of the sheet has passed the pressing portion
201
a,
and the pressing portion
201
b
includes a pressing surface
201
c
to press the sheet further. On the weight member
201
, the upstream side for nipping the pressing portion
201
b
and the downstream side having the pressing portion
201
b
face different directions toward the sheet.
The following is a detailed description of the action of the pressing portion
201
b.
As shown in FIG.
30
(B), by the trailing edge of the sheet passing through the pressing portion
201
a,
the pressing portion
201
a
looses the sheet toward the endless transport belts
18
and the entire weight member
201
swings downward around the support shaft
203
.
The swinging downward of the entire weight member
201
maintains the abutment of the pressing portion
201
c
on the pressing portion
201
b
and the trailing edge of the sheet, and acts to push the trailing edge of the sheet in the direction of discharge while varying its displacement of the abutment with the trailing edge of the sheet.
Note that in this embodiment, with the sheet nipped by the pressing portion
201
a
and the endless transport belts
18
, the directions toward the sheet upstream from the pressing portion
201
a
including the pressing portion
201
b
are different, and the downstream length including the pressing portion
201
b
is set to be longer than the upstream side from the pressing portion
201
a
(the length up to the support shaft
203
). Also, the pressing portion
201
a
is positioned upstream of the endless transport belts
18
while the pressing portion
201
b
is positioned to cross the width of the endless transport belts
18
.
This enables the weight of the pressing portion
201
b,
which is set to be longer, or the weight member
201
lighter and smaller but to efficiently place the weight to press the sheet, because the pressing portion
201
b
applies the pushing pressure to the sheet around the pivot of the pressing portion
201
a.
Also, when the pressing portion
201
b
pushes the trailing edge of the sheet in the aforementioned structure, the weight member
201
itself is smaller and lighter but efficiently presses the sheet. Also, by forming the pressing portion
201
b
to cross the width of the endless transport belts
18
, it is possible to securely discharge the trailing edge of the sheets from the endless transport belts
18
.
FIG.
31
(A) to FIG.
31
(C) shows this transformation. The pressing portion
201
a
is not limited to contact with the sheet shown in FIG.
30
(A) to FIG.
30
(D). It is also perfectly acceptable to use a type wherein the sheet is pressed to the endless transport belts
18
while being in contact with the sheet surface, as shown in FIG.
31
(A) to FIG.
31
(C). Furthermore, in the same drawing, the pressing portion
201
b
is composed of the oblique portions
201
d
and
201
e
whose oblique angles are different. A structure forming the pressing portion
201
b
in a plurality of oblique portions allows variations in the pressing speed and force of the pressing portion
201
b.
As shown in FIG.
31
(A) to FIG.
31
(C), by making the angle of the oblique portion
201
e
steeper than that of the oblique portion
201
d,
the trailing edge of the sheet can be transported slowly at the trailing edge position discharged from the endless transport belts
18
while maintaining good positioning when discharged. As can be seen in FIG.
31
(C), the trailing edge of the sheet is securely fed by the steep angle of the oblique portion
201
e
thereby preventing the trailing edge of the sheet to become nipped between the endless transport belts
18
and the oblique portion
201
e
and getting jammed.
Furthermore, it is also acceptable for the support shaft
203
that supports the weight member
201
to be formed above the downstream side of the endless transport belts
18
rather than above the upstream side, as shown in FIG.
32
(A) and FIG.
32
(B). This makes the direction that the weight member
201
swings different from the embodiment of FIG.
30
(A) to FIG.
30
(D). Note that the length of the pressing portion
201
b
is the same as the apparatus of FIG.
30
(A) to FIG.
30
(D) in view of the point that it is formed longer than the pressing portion.
In each of the aforementioned embodiments, the endless transport belts
18
are used as the transport means opposing the weight member
201
, but it is also acceptable to use the transport roller
118
, shown in FIG.
34
(A) and FIG.
34
(B), when feeding a thick original, such as card or media of a strong nature.
The control depicted in
FIG. 35
to
FIG. 39
has been described for the first embodiment depicted in
FIG. 1
to
FIG. 17
, but it can also be applied to the second embodiment depicted in
FIG. 18
to FIG.
24
(B).
While the above description has been provided to some detail for the embodiments of the present invention, they are details for the structures for the preferred embodiments. They do not prevent a variety of modifications that do not change the scope or the spirit of the arrangements or combinations of the composing elements.
Claims
- 1. A sheet discharge apparatus comprising:sheet storage means for receiving a sheet; discharge means for discharging the sheet transported from a processing apparatus to the sheet storage means; sheet detection means disposed on the sheet storage means for detecting a presence or absence of the sheet on the sheet storage means; aligning means disposed above the sheet storage means for aligning the sheet discharged on the sheet storage means; and control means electrically connected to the sheet detection means and the aligning means for controlling an operation of the sheet discharge apparatus, said control means ignoring a detection result by the sheet detection means when aligning by the aligning means.
- 2. A sheet discharge apparatus according to claim 1, wherein said sheet detection means outputs a signal used in controlling a discharge of the sheet from the processing apparatus.
- 3. A sheet discharge apparatus according to claim 1, wherein said sheet detection means outputs a signal used in stopping the sheet discharge apparatus or the processing apparatus.
- 4. A sheet finishing apparatus comprising:sheet storage means for receiving a sheet; discharge means for discharging the sheet transported from a processing apparatus to the sheet storage means; sheet detection means disposed on the sheet storage means for detecting a presence or absence of the sheet on the sheet storage means; aligning means disposed above the sheet storage means for aligning the sheet discharged to the sheet storage means; finishing means situated adjacent to the sheet storage means for executing a prescribed process on the sheet aligned by the aligning means; and control means electrically connected to the sheet detection means for controlling the sheet finishing apparatus, said control means ignoring a detection result by the sheet detection means when aligning by said aligning means or finishing by said finishing means.
- 5. A sheet finishing apparatus according to claim 4, wherein said sheet detection means outputs a signal used in controlling a discharge of the sheet from the processing apparatus.
- 6. A sheet finishing apparatus according to claim 4, wherein said sheet detection means outputs a signal used in stopping said sheet finishing apparatus or the processing apparatus.
- 7. An image forming apparatus comprising:a sheet discharge apparatus having sheet storage means for receiving a sheet; discharge means for discharging the sheet transported from a processing apparatus to the sheet storage means; sheet detection means disposed on the sheet storage means for detecting a presence or absence of the sheet on the sheet storage means; and aligning means disposed on the sheet storage means for aligning the sheet discharged to the sheet storage means; and control means electrically connected to the sheet detection means for controlling the sheet discharge apparatus, said control means ignoring a detection result by the sheet detection means when aligning the sheet by the aligning means.
- 8. An image forming apparatus according to claim 7, wherein said sheet detection means outputs a signal used in controlling a discharge of the sheet from the processing apparatus.
- 9. An image forming apparatus according to claim 7, wherein said sheet detection means outputs a signal used in stopping the sheet discharge apparatus or processing apparatus.
- 10. An image forming apparatus comprising:an image forming device for forming an image on a sheet; a finishing apparatus having sheet storage means for receiving the sheet; discharge means for discharging the sheet transported from the image forming device to the sheet storage means; sheet detection means disposed on the sheet storage means for detecting a presence of the sheet on the sheet storage means; aligning means disposed above the sheet storage means for aligning the sheet discharged to the sheet storage means; and finishing means for executing a prescribed finishing process on the sheet aligned by the aligning means; and control means electrically connected to the aligning means and the finishing means for controlling the finishing apparatus, said control means ignoring a detection result by the sheet detection means when aligning by the aligning means or when finishing by the finishing means.
- 11. An image forming apparatus according to claim 10, wherein said sheet detection means outputs a signal for controlling a discharge of the sheet from the image forming device.
- 12. An image forming apparatus according to claim 10, wherein said sheet detection means outputs a signal for stopping the image forming device or the finishing apparatus.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2001-042188 |
Feb 2001 |
JP |
|
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