JPH0450872A - Sorter provided with finisher - Google Patents

Abstract

PURPOSE:To enhance the copy productivity as whole by adopting a reciprocating gathering system for a sorter part, and starting a staple processing in th course of sort processing of a sheet to the last document. CONSTITUTION:A sheet discharged from an image forming device is distributed and contained successively into a bin 102, and reciprocating gathering is executed. Subsequently, based on the number of pieces of documents, the bin 102 in which a first sheet to the last document is contained is detected, and before the final sheet of the last document is contained in the bin 102, a staple means 220 is moved to a position corresponding to the pin 102 in which a first sheet is contained. In such a way, even if the remaining sheet to th last document is in the course of sort processing, a staple processing can be started successively from a first sheet contained already, and the copy productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a sorter with a finisher, in particular, a sorter with a finisher, which distributes and stores image-formed sheets discharged from a copying machine, a laser printer, etc. into a plurality of bins, and then stores the stored sheets. Regarding a sorter with a finisher that binds with a stapler.

Conventional TechniquesShi TatsutaIn the past, in the field of copying and printing devices that form images on sheets, various sorters have been developed that automatically align the pages of sheets after images have been formed, and now automatic staplers have been developed. Various sorters with finishers have also been developed.

For this type of sorter with a finisher, what is most desired at present is speeding up of sheet distribution, storage, and binding processing. Therefore, in the sorter section, multiple sheets ejected from the image forming apparatus for one original are transferred from the previous bin to the next bin and from the latter bin to the previous bin each time the original is replaced. The so-called reciprocating collation method, which changes the distribution order, has been put into practical use. However, with regard to the finisher section, a method to increase the speed of sheet binding processing by adapting to reciprocating collation has not yet been solved.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a sorter with a finisher that is compatible with a reciprocating collation system, can complete sheet binding processing in a short time, and can improve overall copy productivity. There is a particular thing.

In order to achieve the above object, a sorter with a finisher according to the present invention includes a plurality of bins for accommodating sheets ejected from an image forming apparatus; a distributing means for distributing sheets to the bins by changing the distribution order from the bin to the bin at the later stage and from the bin at the latter stage to the bin at the earlier stage; stapling means for stapling the sheets stored in the bin; a moving means for moving along a predetermined bin and stopping at a position where sheets stored in a predetermined bin are to be bound;
- detecting a bin in which a first sheet of the last original among the group of originals is stored, and stapling the stapling means to the bin in which the first sheet is stored at least until the last sheet is stored in the bin; A control means for moving the object to a position corresponding to the object.

In the above configuration, the sheets discharged from the image forming apparatus are sequentially distributed and stored in the bins. At this time, when the sheets for the - original are stored sequentially from the first bin to the bin corresponding to the number of sorted sheets, the sheets for the next original are stored sequentially from the bin corresponding to the number of sorted sheets to the first bin. Collation can be executed. In reciprocating collation, if the number of originals is odd, the sheets for the last original can be stored sequentially from the first bin to the next bin, and if the number is even, the sheets for the last original can be stored sequentially from the latter bin to the previous bin. and will be accommodated. Therefore, the distribution order of sheets for the last original among the -group originals is determined based on the number of originals, and the bin in which the first sheet for the last original is stored is determined in advance before the sorting process is completed. .

Therefore, in the present invention, the bin in which the first sheet of the last original is stored is detected based on the number of originals, and the stapling means is activated at least until the last sheet of the last original is stored in the bin. The first sheet is moved to the position corresponding to the bin that can accommodate it. Therefore, even if the remaining sheets for the last original are still being stored in the bin (sorting process in progress), the stapling process can be started sequentially from the first sheet that has already been stored, improving copy productivity. .

Embodiments of a sorter with a finisher according to the present invention will be described below with reference to the accompanying drawings.

[Overall configuration The cosorter 100 includes a copying machine main body 10, as shown in FIG.
It is installed on the side. The copying machine main body 1 is provided with an automatic document feeder 30 (hereinafter referred to as RDH).

The copying machine main body 1 forms an image on a sheet by a well-known electrophotographic method. A photosensitive drum 2, which can be rotated in the direction of arrow a, is first charged with a certain amount of charge by a charger 3. , the optical system 4 scans in the direction indicated by the arrow, whereby the original set at a predetermined position on the original platen glass 29 is exposed to slit light by the RDH 30. As a result, the electrostatic latent image formed on the photosensitive drum 2 is separated from the toner image by the magnetic brush type developing device 5, and transferred to the transfer charger 6.
The image is transferred onto the paper by applying an electric field from the source.

Copying sheets are selectively fed one by one from either a nilevate-type or cassette-type automatic paper feeder 10. Sent. The sheet after the transfer is sent to the fixing device 21 by the conveyor belt 20, where the toner image is fixed, and then sent from the discharge roller pair 22 to the sorter 100, and at this time, the photo sensor SE
Its passage is detected at 4. Further, a paper refeeding device 25 for double-sided copying and composite copying is built into the copying machine main body 1, and a paper conveyance switching claw 26 for this purpose is installed in front of the discharge roller pair 22.

On the other hand, the photosensitive drum 2 continues to rotate in the direction of the arrow a even after the transfer, and the remaining toner is wiped away by a cleaning device 7 with one blade, and the residual charge is erased by an eraser lamp 8, and the next copying operation is performed. Prepare for.

The RDH 30 is well known in itself, and feeds documents placed on a document tray 31 one by one using a paper feed roller 32, passes them through a reversing conveyance section 33, and transfers them to the document table glass 29 by rotation of a conveyance belt 34. Set it in the specified position above. After image exposure, the original is ejected from the ejection roller pair 36 onto the original tray 31 again through the reversing conveyance path 35 as the conveyance belt 340 rotates. Further, the RDH 30 allows a group of originals placed on the tray 31 to pass over the original table glass 29 one by one just before the start of the copying operation, and counts the number of originals.

The number of original sheets counted here is used when controlling the stapling process described below.

[Structure and operation of sorter unit] As shown in FIG. 2, the sorter 100 includes 20 bins 102 for distributing and storing sheets, a vertical conveyance path 110,
Switching claw 120 and discharge roller 1 corresponding to each bin 102
25.126. This sorter 100 is divided into 10 upper bins and 10 lower bins.

The vertical conveyance path 110 includes a vertical guide frame 111. Four conveyance rollers 115, a pinch roller 116 that is in pressure contact with the conveyance rollers 116 and rotates as a result of rotation, a switching claw 120 and a guide plate 124 installed corresponding to each bin 102, and a discharge roller. 125 and a pinch roller 126 that is in pressure contact with the pinch roller 126 and rotates as a result of the pinch roller 125, and the intermediate portion thereof is communicated with each other through guide plates 57 and 58. At the entrance of the sorter 100, there are guide plates 51, 52, sheet receiving rollers 53, 54, and a vertical conveyance path 11 for conveying sheets.
Guide plates 72 and 73 are installed to guide the user to the upper part of 0. Also, as sheet detection means, a transmission type photosensor SE1. SE2, a transmission type photosensor SE3 (
(see Figure 3) is installed.

The switching claws 120, except for the one facing the bottom bin 102, can be rotated around a support shaft 121 by a dedicated solenoid, and when each solenoid is turned off, the switching claws 120 are set to the solid line position in FIG. 2. vertical plane 12
0a (see FIG. 3) and a vertical guide frame 111 to guide the sheet downward. The sheet is conveyed in the longitudinal direction by conveying rollers 115 and 116. On the other hand, switching claw 1
When each solenoid is turned on, the sheet is switched as shown by the dashed line at the top in FIG. 126 to each bin 102. The switching operation of the switching claw 120 is performed based on the timing when the rear end of the sheet can be detected by the sensor SE3. When sheets are distributed and stored in the sort mode, the copy sheets for the odd-numbered originals among the - group of originals are stored in order from the first bin to the bin corresponding to the number of sheets placed (sort set number of sheets), and the copy sheets for the even-numbered originals are stored in order. Copy sheets for the first original are sequentially stored from the first bin to the first bin. When the grouping mode is selected, the set number of copy sheets are stored in the same bin 102, so the switching claw 120 is switched in response to the end of storage of the set number of copy sheets. Further, the lowest stage (20th stage) switching claw 120 has a curved surface 120.
b is fixed at a position where the copy sheet is guided to the bottom bin 102.

[Configuration and operation of finisher section] As shown in FIGS. 2 and 4, the finisher section 300 includes a stapler 220 installed on the front side and a bin 102.
Aligning means 308 for bringing the sheets accommodated in the sheet into contact with the alignment reference plate 102b on the rear side, and the stapler 2
Staple reference plate 102c serves as a reference for engagement with 20
extrusion means 309 for bringing the extrusion means 3 into contact with the extrusion means 3;
09 and the stapler 220 to a position corresponding to each bin 102 (see FIG. 6). Each bin 102 is tilted forward (in the sheet storage direction) and set vertically at a constant interval, and the alignment reference plate 102b and the staple reference plate 102c are integrally attached to each bin 102. It is formed.

Furthermore, each bin 102 has a backflow prevention plate 102a that regulates the rear end of the stored sheets, and has a notch 102 on both sides in which an alignment means 308 and an extrusion means 309 can be moved.
g, 102h, and a cutout 1021 for the operator to manually take out the sheet.

As shown in FIGS. 2 and 4, the alignment means 308 has an alignment rod 303 and a support shaft 304 attached to both ends of the holding lever 302, and is rotatable on a horizontal plane using the support shaft 304 as a fulcrum. be. The alignment means 308 is divided into two parts so as to be able to process the upper bin group and the lower bin group independently, respectively, and each has a drive means (not shown) (for example,
(stepping motor).

The alignment operation is performed for each sheet stored in the bin 102. That is, each time one sheet is stored on the bin 102, the aligning means 308 aligns the fourth sheet with the support shaft 304 as a fulcrum.
Rotate the sheet to the position indicated by the dotted chain line in the figure, and place the sheet on the alignment reference plate 10.
2b to align between the alignment rod 303 and the alignment reference plate 102b. That is, the sheet accommodated in position P1 indicated by the dotted line is aligned to position P2 indicated by the dashed line. Also,
With respect to the sheet storage direction, due to the inclination of the bin 102, the sheets come into contact with the backflow prevention plate 102a under their own weight and are automatically aligned.

As shown in FIGS. 4 and 5, the pushing means 309 has a pushing rod 306 and a spindle 307 attached to both ends of a holding lever 305, and is rotatable on a horizontal plane using the spindle 307 as a fulcrum. , a drive source (for example, a stepping motor) not shown.

This extrusion means 309 is movable to a position corresponding to each bin 102 from the uppermost bin 102 to the lowermost bin 102, and is moved up and down in synchronization with the stapler 220 by a moving means 400 described below. The sheet extrusion operation is performed for each bin 102 in which the sorting operation has been completed. That is, the extrusion means 309 is moved together with the stapler 220 to the side of the bin 102 to be stapled, rotated about the support shaft 307 to the position indicated by the dashed line in FIG. 4, and moves the sheet to the staple reference plate. Press it against 102C. With this, the sheet is aligned at the alignment position P2 shown by the dashed line.
It moves from there to a stapling position P3 indicated by a two-dot chain line, and is engaged with the stapler 220. The stapler 220 operates in this state and staples the sheets. After that, aligning means 3 again
08 inward and press the stapled sheet against the alignment reference plate 102b using the alignment rod 303.

That is, the stapled sheets are returned from the stapling position P3 to the alignment position P2. This is to evacuate the sheet from the stapler 220. Thereafter, the extrusion means 309 and stapler 220 are moved to the next bin position. Note that these series of operations will be explained later with reference to the time chart shown in FIG. 14.

[Structure and operation of stapler and its moving means] As shown in FIG. 7, the stapler 220 has a cam 222 fixed to a motor output shaft 221, and moves the cam 222 with an arm 224 that is swingable about a bin 223 as a fulcrum. The peripheral part and the head 225 are connected, and when the cam 222 is rotated in the direction of the arrow g by a motor, the head 225 moves in the direction of the arrow i via the arm 224, and the staples 226 are aligned on the bin 102. Bind the sheets. The staple needles 226 are straight needles arranged in a plate shape and hardened with adhesive.
A predetermined number of sheets are stored in advance in the cartridge 227 in a state where they are elastically pressed downward by a spring member (not shown), and the conveyor belt 228 is rotationally driven by the motor output shaft 221 one sheet at a time, starting from the lowest layer. is sent to the head section. This stapler 220 also includes staple needles 2.
Reflective photosensor SE5 for detecting the presence or absence of 26
is set, and when the final staple 226 passes the detection point, the sensor SE5 is turned off, and the staple 226
Detects that the is missing. Furthermore, the stapler 22
0 is a photosensor S for detecting the rotation speed of the staple motor.
E6 is installed. This sensor SE6 is designed to detect a notch 209a in a disc 229 fixed to the motor output shaft 221.

On the other hand, the stapler 220 is installed in a protective case 310 erected on the front side of the bin 102, as shown in FIGS. 2 and 4.
It is housed inside so that it can be moved up and down. Protective case 310
has a cover 311 at its upper end that can be opened and closed. The cover 311 is opened during needle replenishment, which will be explained below, and its open/closed state is detected by the switch SWI. Protective case 3
10, the stapler 220 is fixed to a belt 405 that is stretched endlessly around rollers 403 and 404, as shown in FIG. The belt 405 is connected to the roller 4 via the belt 402 from the stepping motor M1.
03 is driven in the direction of arrow C or C'.

The stapler 220 moves up and down as the belt 405 moves in the direction of arrow C or C', and is set to a predetermined bin position. The extrusion means 309 also moves vertically in synchronization with the stapler 220 via a linking means (not shown).

The stapler 220 has normally returned to the home position corresponding to the first bin 102, and the photosensor SE7 detects that the stapler 220 is set at this home position. In the stapling process, the stapler 220
This is done by descending or ascending stepwise one bin at a time in response to bin 102, and binding the sheets on the bin 102 one bundle at a time. The amount of movement of stapler 220 is detected and controlled by the number of pulses that drive stepping motor M1.

When the stapling mode is selected in addition to the sort mode, first, the RDH 30 circulates the originals and counts the number of originals. When the number of originals is an odd number, the copy shift for the last original is distributed from the first pin to the lower bin, so the stapler 220 is set to the home position (position corresponding to the first bin), and the copy shift for the last original is distributed from the first pin to the lower bin. Immediately after the second copy sheet is stored in the first bin and the alignment is completed, stapling processing is started. On the other hand, when there is an even number of originals, the copy sheets for the last original are distributed from the bin to the upper bin, so the stapler 220 is moved to the position corresponding to the bin for the number of copies, and Immediately after the first copy sheet of the original is stored in the predetermined number of bins and alignment is completed, stapling processing is started. Note that such movement control of the stapler 220 will be described in detail with reference to a flowchart.

[Control circuit Figure 8 is a block diagram of the control circuit, and this control circuit is a microcomputer (CP) that controls the copying machine main body 1.
The system is mainly composed of a microcomputer (CPU) 380 that controls the U) 370 and the sorter 100, and both communicate with each other via a bus. CPU370 has RD
A mechanical control section 371 of the H30, a control section 372 of the operation panel, a mechanical control section 373 for copy processing, a main body ejection sensor SE4, and other detection means are connected. Furthermore, various detection means such as the mechanical detection roll SW1 of the sorter 100 are connected to the CPU 380. Also, C
PU380 has random access memory (RAM)
382 is built-in.

[Control Procedure] Next, the control procedure based on the above control circuit will be explained with reference to the flowcharts of FIGS. 9 to 13 and the time chart of FIG. 14. By the way, in the following explanation, on-edge means that a switch, sensor, signal, etc. switches from an off state to an on state, and off-edge means that a switch, sensor, signal, etc. switches from an on state to an off state. means.

FIG. 9 shows the process of counting the number of original sheets in the copying machine CPU 370 as a subroutine.
The main routine 70 and other processes are well known and will therefore be omitted.

Counting of the number of originals starts when a group of originals is placed on the tray 31 of the RDH 30 and a copy start switch on an operation panel (not shown) is turned on. That is, in step 550, a sensor (not shown) provided on the tray 31 determines that a document is placed on the tray 31, and in step 551, it is determined that the copy start switch is on-edge, and in step 552, the number of document sheets is determined. count. The counting process operates the RDH 30 to feed the originals one by one onto the original table glass 29, and then passes through the reversing path 35 and passes through the ejection roller pair 36 onto the tray 31. At this time, the CPU 370 calculates the number of originals. It is counted by the internal counter and stored in memory.

Next, in step 553, it is determined whether or not counting has ended;
If the process is finished, the counted number of originals is sent to the sorter CPU 380 in step 554.

FIG. 10 shows the main routine of sorter CPU 380.

When the CPU 380 is reset and the program is started, in step S1, the RAM 382 is cleared, various registers are initialized, and initial settings are made to put each device into the initial mode.Then, in step S2, an internal timer is started. This internal timer determines the time required for the main routine, and its value can be set in advance in the initial setting at step S1.

Next, after calling each subroutine in steps 53 and 54 to execute necessary processing, the process waits for the internal timer to end in step S5 and returns to step S2.

This long time of one routine is used to count various timers in each subroutine.

Step S3 is a subroutine for distributing and storing sheets into each bin 102, and its details will be omitted. Step S4
The stapler 220 staples the sheets stored in each bin 102.
This is a subroutine for sequentially changing the board, and will be explained below.

FIG. 11 shows the stapler 2 executed in step S4.
20 shows a subroutine for controlling 20.

First, in step 510, the stapling start position of the stapler 220 is set, and in step S11, the stapler 220 starts stapling.
20 to the set stapling start position. In this embodiment, since the sheets are collated back and forth in the sorter unit, if the number of originals is an odd number, copy sheets for the last original are distributed from the upper bin 102 to the lower bin 102. The stapling process starts from bin 1, and if the number is even, the copy sheets for the last original are distributed from the bin 102 corresponding to the set number of sheets to the upper bin 102, so the bin 102 with the set number of sheets
Start stapling processing from . Therefore, the stapler 220 is moved to the stapling start position according to the number of documents.

Next, in step 512, stapling processing is performed, that is, the stapler 220 is lowered (when JK documents are odd numbered sheets) or raised (when M documents are even numbered sheets) step by step from the processing start position one bin at a time. Executes the process of binding sheets. In this embodiment, the extrusion means 309 also moves up and down in synchronization with the stapler 220.

FIG. 12 shows a subroutine for setting the destination of the stapler 220, which is executed in step 510.

First, in step 520, it is determined whether the number of original sheets has been received by CPU 380 or not. The number of W drafts is determined in step 554.
(See FIG. 9) is sent to CP 0380. If the document has been received, it is determined in step 521 whether or not the document is an odd number, and if it is an odd number, the stapler movement destination is set to "1", that is, the home position corresponding to the first bin 102, in step 522. .

If it is an even number of sheets, it is confirmed in step 523 that the copy start signal is on-edge, and in step 524 the stapler movement destination is set to the bin position corresponding to the set number of sheets to be sorted. Note that if the set number of sheets is larger than the number of bins, it is set to "20" (bottom bin position).

FIG. 13 shows a subroutine that is executed in step S11 and moves the stapler to the stapling start position in advance.

First, in step 530, it is determined whether the current position of the stapler 220 is the destination set in step 522 or 524. The current position of the stapler 220 can be confirmed by the number of driving pulses of the stepping motor M1. If No in step 530, the stepping motor M1 is turned on in step 533, and the stapler 220 is raised or lowered toward the destination. Then, if the stapler 220 reaches the destination (YES in step 530),
S), in step 531, the stapler movement destination is set to "0". At the same time, in step 532, stepping motor M1 is turned off to stop stapler 220, and this subroutine ends.

Next, control at the initial stage of the stapling process (executed in step 512) will be described with reference to the time chart of FIG. 14. Here, when the first copy sheet for the last original among a group of originals set in the RDH 30 is completely ejected from the copier main body 1 and stored in a predetermined bin 102, stapling processing is executed and the final The second and subsequent copy sheets of the original are distributed and stored in predetermined bins 102.

It is assumed that the number of sheets to be sorted is "10", the number of originals is an even number, and the stapler 220 has already moved to the tenth bin position.

First, the first copy sheet for the last original is the first copy sheet.
0 bin 102, timing A), 10th
Turn off the pin solenoid (timing B) and turn on the 9th pin solenoid (timing C).

This is preparation for distributing the next copy sheet to the ninth bin 102. Next, the copy sheet is placed in the 10th bin 10.
2, the sheet alignment motor is rotated forward with a slight margin (timing D), the copy sheet is pressed against the reference plate 102b, and then the sheet alignment motor is rotated in reverse (timing E) to rotate the alignment means 308. Bring it back. This is an operation for aligning the copy sheets that have just been stored in the younger brother 10 bin 102. Next, the sheet extrusion motor is rotated forward (timing F), and the 10th bin 10
The copy sheet on 2 is pressed against the reference plate 102c. When the copy sheet is thus set at the stapling reference position, the stapler 220 is turned on at timing G) to staple the copy sheet. When the copy sheets are stapled, the sheet alignment motor is rotated forward while the sheet extrusion motor is rotated in reverse (timing H) to push the copy sheet located at the stapling reference position back to the alignment reference position. When this operation is completed, the stapler moving motor M1 is turned on (timing I), the stapler 220 and the pushing means 309
is moved to the position corresponding to the 9th bin. At the same time, the sheet alignment motor is reversed to return the alignment means 308 to its original position.

When the next copy sheet, that is, the second copy sheet for the last original, is stored in the ninth bin 102 (timing A'), the same operations as described above are performed from timing B' to timing B' to I', respectively. This series of operations continues until the final copy sheet is stored in the first bin 102.

That is, in this embodiment, when the first copy sheet of the last original is stored in a predetermined bin, copy sheets discharged from the copier main body 1 are sorted and are already stored in the bin 102. Stapling the accommodated and aligned copy sheets.

Therefore, the overall copy productivity including sorting processing and stapling processing is increased.

[Other Embodiments] The sorter with a finisher according to the present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the gist.

For example, in addition to using the notch claw 120 as the sheet distribution means, a distribution unit equipped with a conveying tape and a tractor pull tape may be raised and lowered along the sheet entrance portion of the bin.

Regarding the bins 102, it is not necessary that they are divided into two parts each having 10 bins, and it is not necessary to arrange them horizontally.
It may be arranged in a substantially vertical direction, and the sheets may be distributed and accommodated in a diagonally erected state.

Highlights As is clear from the above description, according to the present invention, the reciprocating collation method is adopted in the sorter section, and at least until the final sheet for the last document is stored in the bin,
Since the stapling means is moved to the position corresponding to the bin in which the first sheet of the last original is stored, the stapling process can be started during the sheet sorting process of the last original, and the overall Copy productivity can be increased.

[Brief explanation of drawings]

The drawings show an embodiment of a sorter with a finisher according to the present invention, FIG. 1 is an overall configuration diagram including the main body of the copying machine, FIG. 2 is an internal configuration diagram of the sorter, and FIG. 3 is a sheet diagram that is the main part of the sorter. FIG. 4 is a front view of the distribution section, FIG. 4 is a plan view showing the bin, aligning means, and extruding means, FIG. 5 is a perspective view showing the bin and extruding means, and FIG. 6 is a side view showing the bin, the stapler, and its moving means. , FIG. 7 is a partial sectional view of the stapler, and FIG. 8 is a block diagram of the control circuit. FIG. 9 is a flowchart showing a subroutine for counting the number of originals by a microcomputer that controls the copying machine, FIG. 10 is a flowchart showing a main routine for a microcomputer that controls the sorter, and FIG. Flowchart diagram showing the controlling subroutine, 12th
13 is a flowchart showing a subroutine for setting the destination of the stapler in advance, and FIG. 13 is a flowchart showing a subroutine for preliminarily moving the stapler. FIG. 14 is a time chart showing the operation of stapling processing in parallel with sorting processing. 1... Copying machine main body, 102... Bin, 110...
Vertical conveyance path, 120... Switching claw, 220... Stapler, 300... Finisher section, 370.380
... Microcomputer, 400... Means of transportation.

Claims (1)

[Claims] 1. A plurality of bins for storing sheets ejected from the image forming apparatus, and a plurality of bins for storing sheets ejected from the image forming apparatus; a distributing means for changing the distribution order from a bin to a previous bin and distributing sheets to the bins; a stapling means for stapling the sheets stored in the bins; and a stapling means for moving the stapling means along the bins, a moving means for stopping the sheets stored in the bins at a binding position; and detecting the bin in which the first sheet of the last original among the group of originals is stored, and storing at least the last sheet in the bin. a control means for moving the stapling means to a position corresponding to a bin in which the first sheet is stored.