Sorting apparatus with two sorters

A sorting apparatus of linkage type, which sorts a plurality of recorded sheets which are ejected from an image forming apparatus. The apparatus has at least two sorters, a plurality of bins and a stapling unit in each sorter respectively to store a stack of recorded sheets sorted as a copy set and to staple each stack of recorded sheets and guide means to guide each recorded sheet to a bin of a sorter allocated by controlling means. The controlling means selects at least two sorters for making the copy sets larger in number then a predetermined number. The second sorter receives sheets even though some trays of the first sorter are left unused.

BACKGROUND OF THE INVENTION 
The present invention relates to a sorter that is attached to an image 
forming apparatus such as a copying machine, a printing machine or a laser 
beam printer and receives in each bin multiple copy sheets ejected from 
the image forming apparatus after sorting and grouping them, and more 
particularly, to a sorter with stationary bins wherein a plurality of 
sorters can be linked. 
A type of a sorter sorting and grouping automatically a plurality of sheets 
(copy sheets) ejected from an image forming apparatus such as a copying 
machine includes a type of stationary bins, a type of all movable bins and 
type of each opening and moving bin. 
In the case of a type of stationary bins, when making multiple sets of 
recorded sheets from multiple originals in an image forming apparatus, 
sheets ejected from the image forming apparatus are taken successively in 
a sheet-receiving portion of the sorter, then moved to the transport 
portion, and taken into each bin to be bound in a proper sequence by the 
action of a branch guide (a ranch gate) provided at a sheet-inlet of each 
bin on an allocating unit composed of multiple bins, on a half way of 
transport, thus recorded sheets of multiple sets corresponding to the 
maximum number of bins are arranged methodically. 
The sorters of a type of stationary bins are widely used for high speed 
copying machines of a console type because of advantages that the number 
of sheets to be taken in bins is relatively large, responding speed is 
high and a plurality of sorters can be linked. For example, each of 20 
bins for sorting or grouping can take in about 50 sheets for stacking. 
On the other hand, a sheet finisher provided with a stapler unit that 
staplers sheets ejected from a copying machine or the like includes; 
(1) a sheet finisher that is used in combination with a device such as an 
automatic original-transport unit of a circulating type (RDH) and staples 
each group of sheets, 
(2) a device wherein a stapler unit is provided on a relatively simple 
sorter of a type of movable bins {Japanese Patent Publication Open to 
Public Inspection No. 43457/1989 (hereinafter referred to as Japanese 
Patent O.P.I. Publication)}, which is a sorter in which a stapler unit 
stapling sheets in each bin is arranged to be movable back and forth 
against the bin, 
(3) a sheet finisher wherein a stationary stapler unit is provided on each 
bin and each bin is moved to the stapling position for stapling a bundle 
of sheets, and 
(4) a sheet finisher of a sorter disclosed in Japanese Patent O.P.I. 
Publication No. 244869/1987 wherein a bin holding thereon sheets is moved 
for stapling to the position capable of stapling, and stapling for other 
bins requires bin movement and vertical movement of a stapler unit. 
A sheet ejected from the image forming apparatus mentioned above and 
received by the above-mentioned sorter of a type of stationary bins is 
transported at high speed through the horizontal path and the vertical 
path both in the sorter into each bin mentioned above or onto a non-sort 
tray. 
A plurality of bins in the sorter mentioned above are generally composed of 
the maximum of 20 bins. When sorting sheaves of sheets in quantity of 20 
or more in bins, therefore, a plurality of sorters need to be linked 
together so that sheets ejected from an image forming apparatus may be 
sorted and received successively in each bin of the sorters. 
In conventional sorters of a multiple linkage type, they have been used so 
that the bins of the first sorter may follow the bins of the second 
sorter. Namely, when sorting 21 sets of recorded sheets on sorters each 
consisting of 20 bins, 21st set of recorded sheets is received by the 
uppermost bin of the second sorter only after one through 20 sets of 
recorded sheets have been received by 20 bins of the first sorter in 
succession downward from the top bin. 
In the case of a sorter provided with a stapler unit, stapling for recorded 
sheets in each bin is conducted downward only after all recorded sheets in 
predetermined quantity in each bin have been received by the bin. 
Therefore, it takes a long time to finish stapling, resulting in a long 
down time and poor productivity for the total operation. 
Now, it is assumed that t.sub.1 represents a copying interval, t.sub.2 
represents a stapling interval, and stapling for the first bin is started 
after a copy sheet has been ejected into the first bin. Incidentally, the 
relation of t.sub.2 &gt;t.sub.1 is generally normal. 
In the second sorter, stapling for the 21st set of recorded sheets is 
started after copy sheets have been ejected into the 21st bin, similarly 
to the above. 
Under the assumption that L.sub.1 represents a distance from an image 
forming apparatus to the first bin, L.sub.2 represents a distance from the 
image forming apparatus to the 21st bin, V represents a sheet transport 
speed and N.sub.1 represents the number of sets of copy sheets which is 20 
or less, time T required to cover the finish of copy operation in an image 
forming apparatus through the finish of stapling is as follows. 
EQU T.sub.1 =L.sub.1 /V+t.sub.2 .times.N.sub.1 -t.sub.1 .times.(N.sub.1 -1)(1) 
When N.sub.2 represents the number of sets of copy sheets which ranges from 
20 sets to 40 sets, the time required for the first sorter is as follows. 
EQU T.sub.2 =L.sub.1 /V+t.sub.2 .times.30-t.sub.1 (N.sub.2 -1) (2) 
The time required for the second sorter is as follows. 
EQU T.sub.3 =L.sub.2 /V+t.sub.2 (N.sub.2 -20)-t.sub.1 (N.sub.2 -20)-t.sub.1 
.times.(N.sub.2 -21) (3) 
In this case, time required T is represented by T.sub.2 or T.sub.3 
whichever is greater. 
It has been desired to shorten the aforementioned required time T for 
reducing the down time which makes it impossible to take out all sets of 
copy sheets for use because of unfinished stapling even after the finish 
of copying. 
SUMMARY OF THE INVENTION 
An object of the invention is to solve the problems mentioned above, and 
the object is achieved by a sorter of a linkage type equipped with a 
stapler unit of the invention that receives recorded sheets ejected from 
an image forming apparatus and allocates them into a plurality of bins for 
stapling them wherein when recorded sheets in the number of sets equal to 
or less than the total number of bins in the first sorter of the linkage 
type sorter are received, the stapler is controlled so that the recorded 
sheets may be allocated to the selected bins in the first and second 
sorters to be stacked thereon. 
Further, the linkage type sorter equipped with a stapler unit of the 
invention is further characterized in that the recorded sheets are 
allocated to the selected bins in the first and second sorters to be 
stacked thereon even when recorded sheets in the number of sets exceeding 
the total number of bins in the first sorter of the above-mentioned 
linkage type sorter are received. 
Furthermore, the linkage type sorter equipped with a stapler unit of the 
invention is characterized in that the stapler is controlled so that 
stapling in each sorter can be finished almost concurrently. 
Still further, the linkage type sorter equipped with a stapling unit of the 
invention is characterized in that when recorded sheets are ejected to the 
above-mentioned sorters, the stapler is controlled so that at least a 
plurality of recorded sheets corresponding to the last original may be 
allocated one by one to each sorter mentioned above to be stacked thereon. 
The linkage type sorter mentioned above is further characterized in that 
the stapler is controlled so that when the last recorded sheet stacked on 
the bin in one sorter among those other than the above-mentioned two 
sorters is being paginated and stapled, the last recorded sheet may be 
stacked on a bin of the other sorter.

DETAILED DESCRIPTION OF THE INVENTION 
Examples of the present invention will be explained as follows, referring 
to the drawings. 
FIG. 1 represents a structural diagram of a sorter linked to main body 1 of 
an image forming apparatus such as a copying machine, for example. The 
sorter of the invention comprises pedestal 10, downward sheet-transport 
portion 20, upward sheet-transport portion 30 and bin-moving portion 40. 
The pedestal 10 is connected to the image forming apparatus main body 1 
through connecting means 102 and 103 and is installed on the floor through 
casters 11A and legs 11B. On the top of the pedestal 10, there are affixed 
the downward sheet-transport portion 20 and the upward sheet-transport 
portion 30, and the bin-moving portion 40 can move in the direction 
perpendicular to the drawing plane. The pedestal 10 is further provided 
with lower guide plate 12, transport rollers consisting of transport belt 
13, driving roller 131, driven roller 132 and tension roller 133, a 
plurality of pressure rollers 14A, 14B, 14C and 14D, upper guide plate 15, 
sheet-transport driving means and a pin-moving means. 
On the pedestal (mid-transport portion) 10 mentioned above, there is 
affixed stay member 16A in the direction perpendicular to the plane of 
FIG. 1. Rack gear RG is affixed on the top of the stay member 16A. 
Inside a housing of the bin-moving portion 40, there are supported 
rotatively rolls 17A and 17B for moving the housing, and the rolls 17A and 
17B slide on rail 16B of the pedestal 10 making the housing of the 
bin-moving portion 40 to move in the direction perpendicular to the plane 
of the drawing. 
In the housing of the bin-moving portion 40, there is provided driving 
motor M1 which drives and rotates pinion gear PG through worm gear G1 and 
reduction gear train G2, G3 and G4. Since the pinion gear PG is engaged 
with the rack gear RG affixed on the stay member 16A, the housing of the 
bin-moving portion 40 is moved in the direction perpendicular to the plane 
of the drawing by the driving rotation of the motor M1. Incidentally, the 
numeral 18 represents a rotatable roll provided on a coaxial basis with 
the pinion gear PG, and the roll 18 rotates to guide, being in contact 
with the stay member 16A. 
Next, the downward sheet-transport portion 20 is connected to 
sheet-ejection roller 2 and sheet-ejection outlet 3 of the image forming 
apparatus main body 1, and is affixed on base 101 of the pedestal 10. 
Inside a housing of the downward sheet-transport portion 20, there is 
provided transport belt 22 stretched rotatively between driving roller 23A 
and driven roller 23B, and thereby sheet S ejected from the image forming 
apparatus is guided by guide plate 21 to be transported downward to be 
finally fed into the horizontal transport path in the pedestal 10. In 
addition, branching from the transport path, there are provided transport 
means 24 and tray 25 both are used for ejecting the sheet preceding a 
jammed sheet in the image forming apparatus main body 1 when a jam takes 
place in ADF or a sorter. 
In the upward sheet-transport portion 30, there is endless transport belt 
31 with several strings spread between driving roller 32 located at the 
bottom of a supporting frame and driven roller 33 located at the upper 
position of the supporting frame. An internal surface of the transport 
belt 31 is in contact with a plurality of rotating rollers 34 
corresponding to inlets of bins described later. A plurality of transport 
rollers 35 corresponding to the rollers 34 are in contact with an external 
surface of the transport belt 31 to be rotated. 
Branch guides 36 are located on the half way of the transport rollers 35 
and at the inlets of bins to swing. These branch guides 36 are swung by 
swinging lever 38 provided on the tip of a shaft of rotating shaft 37 and 
solenoids SOL1 through SOL20. Therefore, when the branch guide 36 is 
rotated clockwise, a clam portion of the bottom of the branch guide 36 
engages with a sheet-transport path formed by the transport belt 31 and 
transport rollers 35 to prevent a sheet from moving upward vertically, 
thus the branch guide 36 normalizes the sheet-receiving attitude. When 
sheet S is fed into the normalized sheet-receiving attitude, the sheet is 
deflected along the internal curved surface of the branch guide 36 at 
almost right angles, and it is received by bin 41. 
Namely, the sheet S (shown with dashed lines in the figure) transported 
into the upward sheet-transport portion 30 of a sorter at high speed goes 
up while it is guided between the transport belt 31 and transport rollers 
35. Then the sheet is deflected to the right by the branch guide 36 swung 
clockwise by a solenoid, and passes through the upper portion of the 
vertical stopper wall 41S of the bin 41 to go up toward the right along a 
slant of the bin 41. After the trailing edge of the sheet S passes through 
the upper portion of the stopper wall 41S mentioned above, the sheet S 
changes its movement from rise to a fall and slides with its weight along 
the surface of the bin 41 down to the stopper wall 41S where the sheet S 
stops with its trailing edge hit by the stopper wall. 
A sorter provided with a stapler unit is composed of binmoving portion 40 
that moves a sheet ejected from image forming apparatus main body 1 with 
reference of the center line to the reference position on one side for 
positioning, truing unit 50 that causes sheaves of sheets in a plurality 
of bins 41 to hit the reference wall at one side for truing, a 
sheet-holding unit that presses a sheaf of sheets stacked on each bin, 
bin-moving unit 70 that moves each bin to the predetermined stapling 
position, motor-powered stapler unit 80 that pushes a staple in, and an 
elevating unit that moves upward and downward both bin-moving unit 70 and 
stapler unit 80 together. 
FIG. 2 is a perspective view showing how two sorters are connected to the 
image forming apparatus main body and FIG. 3 is a front sectional view of 
the double-linked sorter. 
The first sorter 100A to be connected to the sheet-ejection portion of the 
image forming apparatus main body 1 is composed of downward 
sheet-transport portion 20, horizontal transport portion 30A and 
bin-moving portion 40A. At two locations at the front and rear at the 
lower portion on the side of base 101 of the horizontal transport portion 
10A facing the side of the image forming apparatus main body 1, there are 
affixed positioning pins 102 which are connecting means. The positioning 
pins 102 are detachably engaged with hole portions of connecting means 103 
affixed on the lower part of the image forming apparatus main body 1, and 
they conduct vertical and horizontal positioning between a sheet-ejecting 
portion of the image forming apparatus and a sheet-receiving portion of 
the downward sheet-transport portion 20 of the sorter. 
After positioning of both units mentioned, leveling of the first sorter 
100A is conducted by means of leg 11B that can move upward and downward, 
and then the image forming apparatus main body 1 and pedestal 10A are 
affixed on an unillustrated plate for finishing installation of the first 
sorter 100A. 
The second sorter 100B to be linked to the above-mentioned first sorter 
100A is composed of horizontal transport portion 10B, upward 
sheet-transport portion 30B and bin-moving portion 40B, and it is common 
with the first sorter 100A in terms of structure except the downward 
sheet-transport portion 20. 
Also at the lower position on the right side of the second sorter 100B, 
there is affixed positioning pin 102 of a connecting means identical to 
that in the first sorter 100A, and the positioning pin 102 is engaged with 
a hole portion of the connecting means 104 affixed at the lower position 
on the left side of the first sorter 100A for positioning. 
At the downstream side in transport of transport belt 13A in the first 
sorter 100A, there is supported branch gate plate 19A so that it may swing 
freely with swinging shaft 191 as the center of swinging. The branch gate 
plate 19A is driven by an unillustrated solenoid (SOL) to swing, and it 
branches to an upward sheet-transport path leading to the aforementioned 
upward sheet-transport portion 30A and to a horizontal sheet-transport 
path leading to the second sorter 100B. The numeral 192 is a stationary 
lower guide plate and it forms sheet-ejecting path 135. 
Incidentally, any of the aforementioned inlet portion 134 and the 
sheet-ejecting path 135 whichever is not used as an opening is closed with 
shielding plates 136 and 137 to prevent foreign materials from entering. 
The aforementioned branch gate plate 19A is normally located at a position 
shown with solid lines, and it leads upward the sheet S which has been 
transported by transport belt 13A along upper guide plate 15A so that the 
sheet S may be received in bin 41A of the first sorter 100A. 
After the sheet S is received in the predetermined bin 41A of the first 
sorter 100A mentioned above, the branch gate plate 19 mentioned above is 
swung by the solenoid to the position shown in FIG. 3 and thereby the 
aforementioned upward sheet-transport path is closed and the horizontal 
sheet-transport path is opened. Therefore, the sheet S transported by the 
transport belt 13A passes through a horizontal sheet-transport transport 
path formed by a bottom guide surface of the branch gate plate 19A and 
lower guide plate 192 to be transported to inlet portion 134 of horizontal 
sheet-transport portion 10B in the second sorter 100B. The sheet S further 
passes through the horizontal sheet-transport portion 10B and a 
sheet-transport path formed by the stationary branch gate plate 19B and 
upper guide plate 15B to go up, and received in bin 41B. 
In the above-mentioned manner, each sheet S is received in each bin 41B of 
the second sorter 100B in succession, thus, sheaves of sheets in quantity 
of a maximum sets of 40 being twice as many as those in each sorter 
including bins 41A of the first sorter 100A can be grouped and received. 
FIG. 4 represents a block diagram of a double-linked sorter equipped with a 
stapler unit of the invention. FIG. 5 is a flowchart showing sorter 
allocation and stapling operations of the invention. "Ready for stapling" 
in this case means that a sheaf of sheets has been received in the first 
bin of a sorter but the sheaf of sheets has not been stapled yet. Further, 
"A-BINS" in this case means the specified number of bins in the first 
sorter and "B-BINS" means the specified number of bins in the second 
sorter. 
Action time of a sorter provided with a stapler unit of the invention will 
be discussed next. 
Under the assumption that N.sub.1 represents the number of bins used in the 
first sorter, N.sub.2 represents that in the second sorter (total number 
of bins used N.sub.T =N.sub.1 +N.sub.2), and T.sub.A represents the time 
required for covering a period from ejection of the last sheet from an 
image forming apparatus to the end of stapling in the first sorter, 
T.sub.A is shown by the following expression; 
EQU T.sub.A 32 L.sub.1 /V+t.sub.2 .times.N.sub.1 -t.sub.1 .times.(N.sub.1 
+N.sub.2 -1) (4) 
wherein, t.sub.1 is a time interval of copying, t.sub.2 is a time interval 
of stapling, V is a linear speed of sheet transport and L.sub.1 is a 
distance between an outlet of an image forming apparatus and the first 
bin. 
Similarly to the above, T.sub.B that is the time required for covering up 
to the end of stapling in the second sorter is shown by the following 
expression; 
EQU T.sub.B =L.sub.2 /V+t.sub.2 .times.N.sub.2 -t.sub.1 .times.(N.sub.2 -1)(5) 
wherein, L.sub.2 is a distance between an outlet of an image forming 
apparatus and the 21st bin. 
The condition of T.sub.A =T.sub.B gives the shortest operation time. 
Due to N.sub.1 +N.sub.2 =N.sub.T, when (N.sub.2 =N.sub.T -N.sub.1) is 
substituted for N.sub.2 in the above expressions, the following 
expressions are obtained. 
EQU T.sub.A =L.sub.1 /V+t.sub.2 .times.N.sub.1 -t.sub.1 .times.(N.sub.T -1)(6) 
EQU T.sub.B =L.sub.2 /V+t.sub.2 .times.(N.sub.T -N.sub.1)-t.sub.1 
.times.(N.sub.T -N.sub.1 -1) (7) 
In the above expressions, the shortest operation time can be obtained when 
both sorters are caused to finish their operations concurrently by setting 
the time required for the first sorter and that for the second sorter to 
be the same (T.sub.A =T.sub.B). Therefore, when the above expressions (6) 
and (7) are caused to be the same, the following expression (8) can be 
obtained. 
EQU N.sub.1 =(-L.sub.1 /V+L.sub.2 /V+N.sub.T .multidot.t.sub.2) / (2t.sub.2 
-t.sub.1) (8) 
When the following values are substituted for items in expression (8), 
expression (9) is obtained. 
L.sub.1 =2000 mm 
L.sub.2 =3000 mm 
V=1000 mm/sec 
t.sub.1 =1 sec 
EQU N.sub.1 =(1+2N.sub.T) / 3 (9) 
The results of Table 1 can be obtained by substituting N.sub.T (=1-40) in 
expression (9). In the expression, N.sub.1 ' represents a value of rounded 
N.sub.1 and N.sub.2 ' is (N.sub.T -N.sub.1 '). 
TABLE 1 
______________________________________ 
N.sub.T N.sub.1 N.sub.1 ' 
N.sub.2 ' (N.sub.T -N.sub.1 ' 
______________________________________ 
) 
1 1 1 0 
2 1.67 2 0 
3 2.33 2 1 
4 3.00 3 1 
5 3.66 4 1 
20 13.6 14 6 
21 14.3 14 7 
22 15.0 15 7 
: 
28 19.0 19 9 
29 19.6 20 9 
: 
39 26.3 20 19 
40 26.7 20 20 
______________________________________ 
For example, the time required for stapling the sheaves of sheets in 
quantity of 20 sets (N=20) in the conventional way is as follows (from 
expression (1)). 
##EQU1## 
Namely, 23 seconds are required for stapling after the finish of copying. 
In contrast to the above, in the sorting system of the invention, when 
setting the first sorter and the second sorter to receive respectively 14 
sets (N.sub.1 =14) and 6 sets (N.sub.2 =6) based on Table 1, and 
substituting these values in the expression (6), the time required for the 
first sorter T.sub.A and that for the second sorter T.sub.B coming from 
expression (7) are as follows. 
##EQU2## 
Therefore, it is possible to shorten the time required from the 
conventional 23 (T.sub.1) seconds to 11 (T.sub.A) seconds in the method of 
the invention mentioned above. 
As described above, finishing time required after copying can be shortened 
and upper bins of each sorter only can be used mainly without necessity of 
using lower bins. Therefore, it is not necessary for users to stoop for 
taking out sheets from lower bins, which contributes to improvement for 
easy operation for the taking out of sheets. 
The second example of a sorter provided with a stapler unit of the 
invention will be explained next. FIG. 6 is a schematic diagram showing a 
transport path through which a sheet is transported to a double-linked 
sorter provided with a stapler unit of the invention, and FIG. 7 is a 
flowchart illustrating the actions of the double-linked sorter. 
(a) The first (odd number) sheet S 1 among a plurality of recorded sheets 
(n sheets) corresponding at least to the last original goes up along the 
upper surface of branch gate plate (branching gate) 19 and is led to the 
first sorter 100A to be received in the uppermost bin 41A 1, thus sorting 
for the first sheaf of sheets is completed. 
(b) Sheet 52 that is a second (even number) sheet among at least the last 
copying is received in the uppermost bin 41B of the second sorter 100B due 
to switching of the branch gate plate 19A and thereby the sorting of the 
second sheaf of sheets is completed. 
(c) During the period of sheet transporting to and sorting in the bin 41B 1 
of the aforementioned second sorter 100B, stapler unit 80A moves to the 
sheaf of sheets (S 1) sorted on the bin 41A 1 of the first sorter 100A and 
staples them. 
(d) Sheet S 3 that is a third sheet among at least the last copying is sent 
again to the first sorter 100A due to the switching of the aforementioned 
branch gate plate 19A, and then is placed on the sheaf of sheets in the 
bin 41A 2 on the second step for the subsequent sorting. 
(e) During the period of the last sheet transporting to and sorting in the 
aforesaid bin 41A 2, stapler unit 80B moves to the sheaf of sheets 
including preceding sheet S 2 on the bin 41B 1 and staples them. 
(f) Likewise, during the period of the last sheet (S 4) transporting to and 
sorting in the bin 41B 2 on the second step of the second sorter 100B, 
stapler unit 80A goes down from the bin 41A 1 to the bin 41A 2 and further 
moves to the sheaf of sheets (S 3) on the first sorter 100A for stapling 
them. 
In the manner mentioned above, each time at least the last recorded sheet 
ejected from image forming apparatus main body 1 is sent in a 
double-linked sorter, branch gate plate 19A switches a sheet-transport 
path between sorter 100A and sorter 100B. Thereby, the recorded sheets are 
sent, on a one by one and alternate basis, to each of sorters 100A and 
100B to be received therein. (41A 1.fwdarw.41B 1 .fwdarw.41A 2.fwdarw.41B 
2.fwdarw.. . . .fwdarw.41A 7.fwdarw.41B 7). During a period wherein the 
last recorded sheet is transported to, received by and sorted in the bin 
of one sorter, a sheaf of sheets the sorting for which has been finished 
in the bin of the other sorter is stapled. 
Therefore, simple control can cause recorded sheets sorted and received in 
both sorters to be stapled almost concurrently. Further, with regard to 
actions such as a fall, a movement, stapling and pushing in of each of 
stapler units 80A and 80B, they are carried out in the vicinity of a bin 
while recorded sheets are being transported to the other bin and paginated 
therein. Therefore, the operation speed of the stapler unit can be a half 
of the conventional speed, resulting in excellence in terms of reduction 
of driving force and vibration as well as stability. 
Incidentally, though the last recorded sheets are sorted to both sorters to 
be received therein through allocation in the above explanation, it is 
also possible to allocate, from the beginning, on a one by one basis, the 
recorded sheets ejected from an image forming apparatus to both sorters. 
As stated above, in a plurality of sorters capable of being connected to an 
image forming apparatus main body in the invention, when the bins of both 
sorters are allocated to be used effectively, the time required for 
finishing of imageprocessed sheets such as for sorting, grouping and 
stapling can be shortened, and thereby processed sheaves of sheets can be 
taken out quickly, resulting in reduction of downtime and improvement in 
easy operation for taking out of sheets.