JP2002370210A - Sheet medium carrier, imaging device and method for letting out staple head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for letting out staple head wherein an action equal to a staple head let out processing can be realized without having a special staple head let out mechanism, and provide a sheet medium carrier and an imaging device. SOLUTION: Whether or not a staple head let out alternate action is necessary is judged (S1204). When judged necessary, whether or not the staple head let out alternate action can be executed is judged (S1205). When judged executable, the staple head let out alternate action is executed. The staple head let out alternate action is an action wherein staple driving out is repeated on a sheet medium for staple head letting out (an ordinary recording sheet may be used) by the required number of drives.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet medium conveying device of an image forming apparatus, and more particularly to a staple fixing process.

[0002]

2. Description of the Related Art A sheet medium used in an electrophotographic image forming apparatus for forming a copy image by transferring a toner latent image on a transfer member to a sheet medium represented by plain paper and then thermally fixing the image. In recent years, various demands have been made for post-processing of a plurality of sheet media after image formation, that is, processing called so-called finishing, in the transport apparatus in recent years due to the expectation of improving the productivity of the user. One type of finishing is stapling.

[0003] Stapling is a process in which a plurality of sheet media is stored in one sheet.
The purpose is to collect one or a plurality of staples in a blank portion of the sheet medium bundle for the purpose of collecting the bundle. A finishing device for executing this stapling process is usually called a stapler unit, and is one of the typical finishing devices.

By the way, the number of staples attached to the stapler unit is reduced every time the stapling process is performed, so that replenishment is required at some point. In addition, when the stapler unit performs the stapling operation, there is a problem in the conveyance of the sheet medium, or when the stapling operation itself fails, a phenomenon such as so-called clogging may occur. There is. In this case, the operator needs to replenish the staples, remove the staples that have failed to be ejected, and the like.

At that time, the stapler unit after removing the staples replenished by the operator or the staples that failed to be ejected is in an unsuitable state for performing the next stapling operation. There are many. Therefore, in a conventional general stapler unit, a staple cueing mechanism that adjusts a staple needle position so that a stapling operation can be performed after the staple needle is re-attached is required in the configuration of the stapler unit.

[0006]

In order to realize the staple cueing mechanism, a sensor unit for detecting an accurate needle position and a control means for controlling the sensor unit are required. However, the stapler unit usually has a device configuration in which a large number of staple bundles can be mounted in advance in order to smoothly process a large amount of staple processing. In addition, it is possible to make the cueing process unnecessary even if no needle is generated by devising the device configuration.

[0007] On the other hand, a phenomenon such as needle clogging is a phenomenon that rarely occurs in normal use, and thus it can be said that the operation of this staple cueing mechanism is extremely rare in practical use. In addition, although the stapler unit was once positioned as a finishing device to increase the productivity of high-priced electrophotographic image forming apparatuses, it has recently been required to mount even relatively inexpensive electrophotographic image forming apparatuses. Therefore, it is demanded by the market to be realized as inexpensively as possible. Also, since the mounting of the sensor unit or the like is one of the factors that limit the miniaturization of the stapler unit itself, it may be a constraint in miniaturizing the electrophotographic image forming apparatus itself.

[0008] Therefore, if the staple cueing mechanism, which is infrequently used in practice, is removed from the apparatus configuration, a needle position detection sensor and various control mechanisms for performing the cueing operation are not required. It is considered to be considerably advantageous in terms of cost.

However, if the stapling operation cannot be performed at all, the stapling operation failure or the like may occur when the next stapling process is performed in the event that the stitching operation is required. Because of the possibility, a problem has arisen that the staple cueing mechanism cannot be simply eliminated.

The present invention has been made under such circumstances, and a sheet medium transporting apparatus and an image forming apparatus capable of realizing an operation equivalent to the needle heading processing without having a special needle heading mechanism. It is another object of the present invention to provide a needle cueing processing method.

[0011]

In order to achieve the above object, according to the present invention, the sheet medium conveying device is configured as described in the following (1) to (13), and the image forming apparatus is configured as the following (1).
4), and the needle cueing processing method is described in the following (1).
5) and (16).

(1) A sheet medium transport means for continuously transporting a plurality of sheet media, and a sheet medium bundle temporarily retaining a sheet medium bundle in which a plurality of sheet media transported by the sheet medium transport means are stacked. Staple means, staple means for performing a staple driving process on the sheet medium bundle temporarily staying in the sheet medium bundle temporary storing means, and the sheet medium having been subjected to staple driving processing by the staple means Discharging means for discharging the bundle outside the apparatus, and performing stapling processing on a sheet medium bundle unit in which a plurality of sheet media conveyed by the sheet medium conveying means to the sheet medium bundle temporarily staying means are stacked. A sheet medium transport device that can be ejected out of the machine after the staple device has a stapling device. In the case where no special means for performing a needle cueing operation for returning the next needle driving operation into executable circumstances in the context, minimum 1
Performing a staple driving process by the staple means once or a plurality of times on the staple staple cueing sheet medium after the staple staple cueing sheet medium is conveyed to the sheet medium bundle temporary holding means. A sheet medium transport device provided with a control unit for executing the same as a take-out substitute operation.

(2) In the sheet medium transport apparatus according to the above (1), the condition in which the staples cannot be driven may be caused after the staple supply without the staples is performed or during the staple driving process. The sheet medium transport device after the recovery process for the defect or both.

(3) The sheet medium transport device according to (1) or (2), wherein the staple staple cueing sheet medium is also used as a normally transported sheet medium.

(4) The sheet medium transport apparatus according to any one of the above (1) to (3), further comprising: an instruction unit for instructing an operator to start the needle head replacement operation by the operator. A sheet medium transporting device that executes the needle leading alternative operation according to an instruction.

(5) In the sheet medium conveying apparatus according to the above (4), the sheet medium conveying apparatus is provided with a notice and a warning for notifying and warning an operator that it is necessary to execute the needle heading alternative operation. apparatus.

(6) In the sheet medium transport apparatus according to the above (4) or (5), a staple leading alternative operation necessity determining means for determining whether or not a staple leading alternative operation is necessary, and a case where the determining means determines that it is necessary. A conditional prohibition means for prohibiting a sheet medium conveyance operation accompanied by execution of a staple staple driving process by the staple means, and when the staple head replacement operation necessity determination means determines that the execution of the staple head replacement operation is necessary; , A sheet medium transporting device that inhibits execution of a sheet medium transporting operation accompanied by execution of the staple driving process until an operator instructs and executes the staple leading alternative operation.

(7) In the sheet medium transporting device according to any one of (1) to (6), a needle heading alternative operation for judging that the apparatus is in a state where the needle heading alternative operation can be executed. A needle locating alternative only when the driving of the staple is impossible and the needle locating alternative operation determining unit determines that the needle locating alternative operation is executable. A sheet medium transport device that performs an operation.

(8) In the sheet medium transport apparatus according to (7), at least one staple staple cue sheet medium is set in the sheet medium transport apparatus as an apparatus state in which the stapling alternative operation can be executed. A sheet medium conveying device in a state where the sheet medium can temporarily be conveyed by the sheet medium bundle temporarily staying means.

(9) In the sheet medium transporting apparatus according to the above (7) or (8), a staple staple is provided with a staple leading alternative operation automatic start means capable of automatically starting the staple leading alternative operation. Automatically start and execute the needle heading alternative operation when it is determined that the needle heading alternative operation can be executed by the needle heading alternative operation determination unit. Sheet media transport device.

(10) In the sheet medium transport apparatus according to (9), the automatic start and execution of the staple leading alternative operation by the staple leading alternative operation automatic starting means involves execution of the next staple staple driving process. The sheet medium transport device immediately before the sheet medium transport operation.

(11) In the sheet medium transport device according to any one of the above (1) to (10), a non-volatile memory for storing that the sheet medium transport device is in a state in which staples cannot be driven. The storage means of the sheet medium is referred to at any time as to whether it is impossible to drive the staples stored in the storage means, and according to the result, the sheet medium transport device is unable to drive the staples. The sheet medium transport device that determines whether the sheet is present.

(12) In the sheet medium transport apparatus according to the above (11), the non-volatile storage means makes it impossible for the sheet medium transport apparatus to drive staples even after the power of the sheet medium transport apparatus is turned off. A sheet medium transporting device capable of storing whether or not the sheet medium is in a normal state.

(13) In the sheet medium transport apparatus according to the above (11), the staple driving may be performed in advance as an initial value of information on whether or not the staple driving stored in the storage means is disabled. By storing that the staple feeding operation is not possible, even when the sheet medium conveying operation accompanied by the execution of the staple staple driving process is executed for the first time by the sheet medium conveying device, the staple leading operation is always performed. Sheet medium transport device.

(14) An image forming apparatus provided with the sheet medium conveying device according to any one of (1) to (13).

(15) Step A for judging whether or not the needle-pointing alternative operation is necessary, and Step B for judging whether or not the needle-pointing alternative operation can be executed when it is judged necessary in this step A, and executing in this step B. And a step C of executing a needle heading alternative operation when it is determined that the needle heading can be performed.

(16) In the needle cueing processing method according to the above (15), the needle cueing alternative operation is an operation of repeating the stapling of the needle cue sheet sheet a required number of times.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples of an image forming apparatus.

[0029]

1 to 7 show an embodiment of an "image forming apparatus".
It is a drawing showing composition of. The basic configuration will be described based on these.

First, the configuration of the color reader will be described. FIG. 3 shows the overall configuration of the image forming apparatus according to the embodiment. Here, 101 is a CCD, 311 is a substrate on which the CCD 101 is mounted, 300 is a control unit for controlling the entire image forming apparatus, 312 is a part of the image processing unit in FIG. 1 excluding the CCD 101 and 201, 202 to 202 in FIG. A printer processing unit including a portion 205, a platen glass 301 (platen),
Reference numeral 02 denotes a document feeder (DF) (a mirror pressure plate (not shown) may be mounted in place of the document feeder 302). Reference numerals 303 and 304 denote light sources (halogen lamps or fluorescent lamps) for illuminating the document. , 305 and 306 are light sources 30
307-30, a reflective umbrella that condenses 3,304 lights on the original
9 is a mirror, 310 is the reflected light or projected light from the original
A lens 314 for condensing light on the CD 101 is a halogen lamp 303, 304, reflectors 305, 306, and a mirror 30.
7, a mirror 308, 30
A carriage 313 for accommodating the device 9 is an external interface (I / F) with another device. Note that the carriage 314 has a velocity V, and the carriage 315 has a velocity V / 2.
Then, the entire surface of the document is scanned (sub-scanning) by mechanically moving the CCD 101 in a direction perpendicular to the electrical scanning (main scanning) direction.

The control unit 300 has an I / F for exchanging information for controlling the digital image processing unit 312, the external I / F 313, and the printer control I / F 353 as shown in FIG. It comprises a CPU 401, an operation unit 402, and a nonvolatile memory 403. The operation unit 402 is configured by a touch panel-equipped liquid crystal for inputting processing execution contents by the operator, information on processing for the operator, and notification of a warning or the like.

The external I / F 313 is an interface for exchanging image information, code information, and the like with the outside of the image forming apparatus. More specifically, the external I / F 313 can be connected to a personal computer terminal, a LAN interface, or the like. . The control of the exchange procedure of the image information and the code information with the personal computer terminal device and the LAN interface device is performed by each connection device and the CPU of the control unit 300.
This is performed by mutual communication with 401.

Next, the digital image processing unit 312 will be described in detail. FIG. 1 is a block diagram showing a detailed configuration of the digital image processing unit 312.

Documents on the platen glass are light sources 303 and 30
4 is reflected, and the reflected light is guided to the CCD 101 and converted into an electric signal. (If the CCD 101 is a color sensor, even if the RGB color filters are inlined in RGB order on a one-line CCD, 3 lines C
In a CD, an R filter, a G filter, and a B filter may be arranged for each CCD, or the filter may be on-chip or the filter may be configured differently from the CCD. Then, the electric signal (analog image signal) is input to the image processing unit 312,
Clamp & Amp. The sample and hold (S / H) is performed by the & S / H & A / D unit 102, the dark level of the analog image signal is clamped to the reference potential, and is amplified to a predetermined amount (the processing order is not limited to the notation order). The signal is D-converted and converted into a digital signal of, for example, R, G, and B each having 8 bits. Subsequently, the R, G, and B signals are output to the shading unit 10.
At 3, shading correction and black correction are performed. In this embodiment, since the latent image is formed on the photosensitive drum by causing the LED array to emit light in the image forming unit of the printer, it is necessary to perform LED shading correction in addition to normal shading correction. RGB after correction
The signal is further supplied to the connection & MTF correction & document detection unit 104
In the case where the CCD 101 is a three-line CCD, the splicing process differs in the reading position between the lines. Therefore, the delay amount for each line is adjusted according to the reading speed, and the signal timing is adjusted so that the reading positions of the three lines become the same. In the MTF correction, since the reading MTF changes depending on the reading speed and the magnification, the change is corrected, and in the document detection, the document size is recognized by scanning the document on the platen glass.

The digital signal whose read position timing has been corrected is input to the CCD 101 by the input masking unit 105.
And the light sources 303 and 304 and the reflector 305,
The spectral characteristic of 306 is corrected. Input masking unit 105
Is a selector 1 that can be switched with an external I / F signal.
06. The signal output from the selector 106 is input to the color space compression & background removal & LOG conversion unit 107 and background removal unit 115. After the signal input to the background removal unit 115 is removed from the background, the signal is input to a black character determination unit 116 that determines whether or not the document is a black character in the document, and a black character signal is generated from the document. In addition, the color space compression & background removal & LO
The G conversion unit 107 determines whether the read image signal is within the range that can be reproduced by the printer in the color space compression. If the image signal is present, the image signal is within the range that can be reproduced by the printer. Correction as follows. Then, a background removal process is performed, and RGB conversion is performed by LOG conversion.
The signal is converted into a CMY signal. Then, the timing of the output signal of the color space compression & background removal & LOG conversion unit 107 is adjusted by the delay 108 in order to correct the signal generated by the black character determination unit 116 and the timing. The two types of signals are subjected to moiré removal by the moiré removal unit 109 and subjected to scaling processing in the main scanning direction by the scaling unit 110. 111 is U
In the CR & masking & black character reflection unit, the CMY signal is processed by the UCR process to generate a CMYK signal for the signal processed by the scaling unit, and the masking processing unit corrects the signal to the signal output from the printer. Is fed back to the CMYK signal. U
The signal processed by the CR & masking & black character reflection unit 111 is subjected to density adjustment by the γ correction unit 112 and then to the filter unit 11.
In step 3, smoothing or edge processing is performed. The signal processed as described above is converted from an 8-bit multi-level signal to a binary signal by a binary conversion unit 201 (see FIG. 2) (the conversion method may be any of dither method, error diffusion method, and an improved error diffusion method). It doesn't matter.)

Next, the configuration of the printer unit will be described. In FIG. 3, reference numeral 353 denotes a printer control I / F, which serves as a port for receiving a control signal from the CPU 401 of the color reader unit. The printer unit performs an operation described below based on a control signal from the printer control I / F 353.

Next, the image forming section will be described in detail. In FIG. 3, 317 is an M image forming unit, 318 is a C image forming unit, 319 is an M image forming unit, and 320 is a K image forming unit. Since the configurations of the image forming units 317 to 320 are all the same, the M image forming unit 317 will be described in detail below, and the description of the other image forming units will be omitted.

In the M image forming unit 317, reference numeral 342 denotes a photosensitive drum, on which a latent image is formed by light from the LED array 210. Note that data for causing the LED array 210 to emit light is generated by the digital image processing unit 312 based on the RGB signals obtained by scanning the original read by the color reader unit.
The image signal is either a value image signal (hereinafter abbreviated as a scanner image signal) or a binary image signal input from outside the image forming apparatus via the external I / F 313. As described above, the scanner image signal is a signal that has been subjected to LED shading correction corresponding to the characteristics of the individual LED elements constituting the LED array 210 in advance. Therefore, the LED element that emits light based on a certain image signal is predetermined at the time of generating the image signal, and cannot be changed in order to perform optimal image formation. However, the image signal from the external I / F 313 is not limited because it is not necessary to perform the LED shading correction.

Reference numeral 321 denotes primary band electricity, and the photosensitive drum 342
Is charged to a predetermined potential to prepare for latent image formation. A developing device 322 develops the latent image on the photosensitive drum 342 to form a toner image. Note that the developing device 322 has a sleeve 3 for applying a developing bias to perform development.
45 are included. Reference numeral 323 denotes transfer belt electricity, which discharges from the back of the transfer belt 333 to transfer the toner image on the photosensitive drum 342 to a recording sheet medium on the transfer belt 333. In this embodiment, since the transfer efficiency is good, the cleaner portion is not provided (it goes without saying that there is no problem even if the cleaner portion is attached).

Next, the procedure for forming an image on a recording sheet medium will be described. First, the operation of transporting the recording sheet medium in the paper feeding unit will be described. Cassette 340, 3
The recording sheet medium stored in the paper feed unit 41 and the manual paper feed unit 353 is conveyed one by one onto a paper feed path by the pickup rollers 339 and 338. The recording sheet medium on the paper feed path is fed to the registration rollers 35 by paper feed rollers 336 and 337.
5, the passage of the recording sheet medium is detected by the registration sensor 356 immediately before. Registration sensor 3
In this embodiment, when the passage of the recording sheet medium is detected by 56, the conveyance operation is temporarily interrupted after an appropriate time has elapsed. As a result, the recording sheet medium collides with the stopped registration roller 355 and the conveyance is stopped. At this time, the position of the recording sheet medium is fixed so that the end of the recording sheet medium in the traveling direction is perpendicular to the conveyance path, and the recording is performed. When the skew occurs due to the shift of the conveyance direction of the sheet medium with respect to the conveyance path, the conveyance direction of the feeding path is corrected.
This process is usually referred to as “feed registration”. The paper feed registration is indispensable in order to minimize the inclination of the image forming direction with respect to the recording sheet medium thereafter. After the paper feed registration, the registration roller 355 is activated to supply the recording sheet medium onto the transfer belt 333.

Next, a procedure for forming an image on the recording sheet medium supplied onto the transfer belt 333 will be described. The fed recording sheet medium is supplied to the attraction charger 34.
Charged at 6. Reference numeral 348 denotes a transfer belt roller which drives the transfer belt 333 and charges the plain paper or the like in pairs with the attraction charger 346 to attract the recording sheet medium to the transfer belt 333. Reference numeral 347 denotes a sheet medium leading edge sensor which detects the leading end of the recording sheet medium on the transfer belt 333. The detection signal of the sheet medium leading edge sensor 347 is sent from the printer unit to the color reader unit, and is used as a sub-scanning synchronization signal when a video signal is sent from the color reader unit to the printer unit.

Thereafter, the plain paper is conveyed by the transfer belt 333, and the image forming units 317 to 320 carry the MCY.
A toner image is formed on the surface in the order of K. The plain paper that has passed through the K image forming unit 320 is separated from the transfer belt 333 after being neutralized by a neutralization charger 349 to facilitate separation from the transfer belt 333. Reference numeral 350 denotes a peeling charger, which prevents image disturbance due to peeling discharge when plain paper is separated from the transfer belt 333. The separated plain paper is charged by pre-fixing chargers 351 and 352 in order to compensate for the attraction of toner and prevent image disturbance.
Further, after the toner image is heat-fixed by the fixing device 334, the conveyance path is switched to the paper discharge path 358 by the paper discharge flapper 357, and the paper is conveyed to the staple finisher unit 335.

FIG. 2 is a block diagram showing a detailed configuration of the printer processing unit. The LED image recording will be described with reference to FIG. The binary CMYK image signal generated by the digital image processing unit of FIG. 1 is converted into a signal generated by the binary conversion unit based on the paper leading edge signal from the paper leading edge sensor 347 by delay units 202 to 205, respectively. By adjusting the difference in the distance between the leading edge sensor and each image forming unit, four colors can be printed at predetermined positions. LED
The drives 206 to 209 generate signals for driving the LEDs 210 to 213.

Next, the operation for forming an image on the back surface of the recording sheet medium will be described in detail. When forming an image on the back surface of the recording sheet medium, first, image formation on the front surface of the recording sheet medium is performed.
The operation of forming an image on the front surface has been described in detail above and will not be described here. However, in the case of forming an image on only the front surface, after the toner image is thermally fixed by the fixing device 334 after image formation, the discharge flapper 357 Is switched to the paper discharge path 358 side, and the paper is discharged to the paper discharge tray 335 as it is. However, when image formation on the back side is performed subsequently, the paper path is switched to the back side path 359 by the paper discharge flapper 357. The recording sheet medium is once conveyed into the two-sided reversing path 361 by the rotation of the reversing roller 360 in accordance with the rotation. After that, the recording sheet medium is conveyed into the two-sided reversing path 361 by the width of the sheet medium in the feeding direction, and then the reverse direction of the reversing roller 360 and the driving of the two-sided path conveying roller 362 change the traveling direction by the two-sided reversing path guide. The sheet is conveyed to the double-sided path 363 with the image surface formed on the front side being turned down. It should be noted that a reversing path sensor is provided inside the two-side reversing path 361, and it is possible to detect the stay of the recording sheet medium in the two-side reversing path 361. However, the reversing path sensor is not used to determine the position of the recording sheet medium being conveyed in the recording sheet medium conveyance sequence, but is used when paper stagnation occurs due to conveyance failure and when the apparatus is turned on. It is used to detect that the recording sheet medium stays inside the double-sided inversion path 361.

Subsequently, the recording sheet medium is a double-sided pass 363.
When the sheet is conveyed upward to the re-feed roller 364, the passage of the recording sheet medium is detected by the re-feed sensor 365 immediately before. In this embodiment, when the passage of the recording sheet medium is detected by the re-feed sensor 365, the conveyance operation is temporarily interrupted after an appropriate time has elapsed. As a result, the recording sheet medium collides with the stopped re-feed roller 364, and the conveyance is temporarily stopped. At this time, the position of the recording sheet medium is fixed so that the end of the recording sheet medium in the traveling direction is perpendicular to the conveyance path. When the skew occurs due to the conveyance direction of the recording sheet medium being deviated from the conveyance path in the re-feed path, the conveyance direction of the re-feed path is corrected. This process is usually called "re-feed registration". The refeed registration is indispensable in order to minimize the inclination of the image forming direction with respect to the back surface of the recording sheet medium thereafter. After the re-feeding registration is completed, the re-feeding roller 364 is activated, so that the recording sheet medium is re-passed in the re-feeding path 36
6 and a paper feed path. Subsequent image forming operations are the same as the above-described front surface image forming operations, and will not be described here. The recording sheet medium on which images are formed on both front and back sides is discharged as it is to the discharge flapper 3.
The transport path is switched to the paper discharge path 358 side by 57,
The sheet is conveyed to the staple finisher 335 as it is. With the above operation, in this embodiment, it is possible to automatically form images on both sides of the sheet medium without the operator having to set the front and back of the sheet medium again.

Next, the configuration of the staple finisher 335 will be described in detail with reference to FIG. In the staple finisher unit 355 in this embodiment, two types of operations, an end staple operation and a saddle stitch operation, are possible.

First, the end stapling operation will be described. First, the recording sheet medium conveyed from the printer unit is conveyed to the inside of the staple finisher unit 335 by the first conveying roller 501, and then the branch flapper 502.
The conveyance path is switched to the end staple path 503 and the sheet is conveyed to the second conveyance roller 504. After the recording sheet medium that has passed through the second conveyance roller 504 is once conveyed to the vicinity of the exit on the staple tray 505,
When the staple tray alignment belt 506 rotates in the reverse direction, the staple tray 505 is pulled back to the far end and stopped. The same conveyance is performed for the subsequent recording sheet medium, and the recording sheet medium is temporarily accumulated on the staple tray 505 by being superimposed on the recording sheet medium conveyed earlier.

When an arbitrary number of recording sheet media have stayed, the end stapler 507 operates, and the staples are struck while the superposed recording sheet media are bundled to bind the recording sheet media bundle. . The stapler 507 can be moved in the front-rear direction, and the stapling position of the staple can be selected from one of front-side binding, rear-side one-point binding, and front-back two-point binding.

The sheet bundle for recording on which staple binding has been performed is driven by a discharge roller 508 so that the discharge tray 5 is driven.
09 is discharged.

Next, the saddle stitch operation will be described. First, the recording sheet medium conveyed from the printer unit is conveyed to the inside of the staple finisher unit 335 by the first conveying roller 501, and then the branch flapper 502.
The conveyance path is switched to the saddle stitch path 510 by the above-described operation, and the conveyance path is conveyed to the third conveyance roller 511. The recording sheet medium that has passed through the third transport roller 511 temporarily stops in the saddle stitch tray 511. The same conveyance is performed for the subsequent recording sheet medium, and the recording sheet medium is temporarily accumulated in the saddle stitch tray 511 by being superimposed on the recording sheet medium that has been conveyed earlier.

When a given number of recording sheet media have accumulated, the two saddle staplers 512 (a) and 512 (b) arranged at the front and back are operating, and the stacked recording sheet media are bundled. And the staples are hit and the sheet bundle for recording is bound. Subsequently, the pushing plate 513 is operated in the discharging direction, and the saddle folding roller 514 folds the recording sheet medium bundle into two while the saddle discharging path 51 is being folded.
5 is conveyed. The folded sheet medium bundle is folded by the saddle discharge roller 516 into the saddle discharge tray 51.
7 is discharged.

Now, the configuration of the end stapler 507 and the details of the needle driving operation will be described with reference to FIG.
The needle cartridge 601 of the end stapler 507 has a needle plate stacker 6 in which a plurality of needle plates 602 each having a single plate shape formed by bonding a plurality of needles are stored.
03 and a needle plate transport guide 604 for transporting the lowermost needle plate 602 to a portion where needle punching is performed.

When the needle cartridge 601 is mounted on the stapler, the lowermost needle plate 602 of the cartridge 601 is transported by the needle plate transport roller 605 toward the tip of the needle plate transport guide 604. The tip of the needle plate transport guide 604 has a convex shape protruding by the width of the needle to be stapled, and is relatively concave.
Moves in the needle driving direction, the needle on the back side for one needle
As shown in the figure, only the needle located at the forefront, which has already been formed into a U-shape by the previous operation of the needle abutting plate 606, is pushed out by the needle abutting plate 606,
The recording sheet is ejected on a sheet bundle 608. A needle bending plate 609 is located above the recording sheet medium bundle 608, and the needle pushed out by the operation of the needle pushing plate 606 and penetrating the recording sheet medium bundle 608 is the needle bending plate 60.
9, the sheet bundle for recording 608 is stapled. Then, after returning the needle plate 606 to the original position, the needle plate transport roller 605 is driven to move the needle plate 602 by a distance corresponding to one needle to prepare for the next needle driving operation.

The needle plate 602 in the needle plate stacker 603 is pressed down by the needle plate pressing spring 610 in the stacker, and keeps pressing the button-type sensor 611 located below the needle plate stacker 603 at all times. Thus, it is detected that the needle plate 602 remains. By the stapling operation, the needle plate 602 in the needle plate stacker 603 is consumed, and when none of the needle plates 602 in the needle plate stacker 603 runs out, the button type sensor 611 is not depressed. As a result, there is no needle in the needle plate stacker 603. Is detected.

Further, the end stapler 507 has a function of executing the cueing of the needle. When the needle plate 602 reaches the tip of the needle plate transport guide 604, the needle plate 602 presses the end of the needle head detection flag 612, and the opposite end of the needle head detection flag 612 blocks the photo interrupter 613, so that the needle plate 60
2 is detected to have reached the tip of the needle plate transport guide 604. Therefore, it is possible to perform the needle head positioning by repeatedly performing the needle driving operation until the needle plate tip detection is performed. This needle cueing operation is automatically executed when the needle end of the needle plate is not detected by the photo interrupter 613 after the needle cartridge 601 is mounted.

The saddle staplers 512 (a) and 512 (b) are configured as shown in FIG. 7 with respect to the end stapler 507 having such a configuration. First, the needle cartridge 701 is connected to the needle cartridge 6 of the end stapler 507.
Unlike the first stapler 701, only the needle plate stacker 702 is provided, and the needle plate transport guide 703 of the end stapler 507 remains in the stapler main body even after the needle cartridge 701 is removed. Therefore, even when the cartridge is replaced when the needle in the needle plate stacker 702 has run out, it is not necessary to perform the needle cueing operation. Therefore, the necessity of performing the needle cueing operation as compared with the end stapler 507 is reduced as much as possible. Let me.

Further, the saddle stapler 512 (a),
(B) Needle cartridge 601 of end stapler 507
The stapler stapler 512 (a), (b) is not provided with a portion corresponding to the needle heading detection flag 609 and the photo interrupter 610 in FIG.
7, the size of the stapler itself can be made smaller, and the size of the staple finisher can be made more compact. In addition, since the number of parts can be reduced, it can be said that the configuration is more advantageous in terms of cost.

However, by adopting the above configuration, the saddle stapler 512 (a), 512 (b) cannot automatically perform the needle leading operation. Needless to say, since the driving portion related to the needle driving operation is equivalent to the end stapler 507, it is possible in principle to perform the needle heading itself by repeating the needle heading operation at an arbitrary fixed number of times. However, because it is not possible to detect that the tip of the needle plate has reached the needle heading position, there is a possibility that an empty needle driving operation may be performed accidentally.In that case, the empty needle is scattered inside the staple finisher. It will be. Since the idled needle is usually a metal piece, it may fall on an electric control board or the like of the staple finisher and cause a fatal obstacle such as a short circuit (short circuit).

Therefore, in the present embodiment, in order to avoid the problem, the following procedure is executed as a needle leading alternative operation, so that the needle leading can be realized as a result. The procedure will be described in detail with reference to the flowchart of FIG.

First, in step S801, execution of the needle heading alternative operation is instructed to the apparatus, thereby starting execution of the needle heading alternative operation.

In step S802, a sheet medium for locating a staple for the staple-locating alternative operation is fed from one of the cassettes 340 and 341 of the printer unit and the manual feed unit 353. At this time, the sheet medium for needle leading need not be a special sheet medium, and is also used for forming an image normally.

Subsequently, in step S803, the sheet medium for leading the staple is conveyed to the staple finisher unit 335, and once stopped in the saddle stitch tray 511 via the saddle stitch path 510, stops. In this case, it is not necessary to use a special path for the transport path, and the transport path of the recording sheet medium during normal image formation is used. However, in this case, of course, the operation of the image forming units 317 to 320 is not performed at all because there is no need to form an image.

Next, in S804, the saddle stapler 51
2 (a) and (b) are operated and the saddle stitch tray 51 is operated.
The needle driving operation is performed a plurality of times on the sheet medium for needle head positioning stopped in 1. The number of times of punching at this time is determined based on the device configuration and results, and is set to be at least the number of times that the tip of the needle plate is considered to reach the needle head position. Therefore, when this operation is completed, the saddle stapler 512
(A) and (b) are in the same state as when the needle head is set. In this case, since it is not possible to detect that the tip of the needle plate has reached the needle leading position, there is a possibility that the needle driving operation may be performed further after the tip of the needle plate reaches the needle leading position. However, even at that time, the needle that has been accidentally ejected is stapled on the sheet medium for locating the needle, so that the needle is not scattered in the machine, and a fatal trouble such as a short circuit (short circuit) is caused. Possible causes can also be avoided.

Finally, in step S805, the sheet medium for leading the needle is discharged out of the apparatus. Since the details of the external discharge operation have been described above, they are omitted here.

In the present embodiment, the operator instructs the start of the needle heading alternative operation described in detail in the flow of FIG. 8 through the operation unit 402 (see FIG. 4) of the image forming apparatus. It is possible. FIG. 9 shows an example of an instruction screen interface for that purpose. The operator can instruct the start of the needle heading alternative operation at an arbitrary timing via the screen interface of the operation unit 402 shown in FIG. However, since it is difficult for the operator to determine whether the device status requires the needle heading alternative operation, the device side determines whether the needle heading alternative operation is necessary, and notifies the operating unit 40
2 need to be notified to the operator. In the present embodiment, as described above, it is unnecessary to perform the same process when the needle cartridge is replaced due to the absence of the needle. In this case, it is limited to the case where the conveyance failure of the recording sheet medium in the saddle finisher has occurred, or the malfunction of the saddle stapler 512 (a) or (b) itself has occurred. In the present embodiment, when such a situation occurs, as a result, after performing a series of return processing such as removing the recording sheet medium remaining in the apparatus, the operation unit 402 informs the user that the needle leading alternative operation is necessary. Notify or warn the operator via the interface. FIG. 1 shows an example of the display screen interface of the operation unit 402 at that time.
0 is shown. The operator instructs the start of the needle heading alternative operation from the needle heading alternative operation start instruction screen described above according to the screen display, but in the unlikely event that the instruction is not performed,
If the sheet is transported with the subsequent saddle stitch operation, there is a possibility that the correct saddle stitch processing is not performed. Therefore, in order to avoid this, in the present embodiment, when the execution of the subsequent saddle stitching operation is instructed in a situation where the operator does not instruct the start of the needle heading alternative operation, the needle heading alternative operation is executed first. If not, a message that the process cannot be executed is displayed on the operation unit 402, and
Execution of saddle stitch operation is prohibited. Thereby, in the present embodiment, the possibility that the saddle stitch operation is executed in a state where the needle leading is not performed is avoided.
FIG. 11 shows an example of the operation unit 402 display screen interface at that time.

In the present embodiment, the saddle stapler 512 is reliably used in the present embodiment by the above-described series of interfaces in a situation where a needle head replacement operation is required and before the sheet is transported with the next saddle stitch operation.
(A) and (b) can be performed. However, as described above, the determination as to whether there is a possibility that the needle heading operation is originally required can be made without using the operator's hand in the apparatus. Accordingly, it is also possible for the apparatus to automate the execution itself of the needle heading alternative operation.

Therefore, in the present embodiment, the series of interfaces so that the needle leading operation can be surely performed by the interface is provided to the operator, and when the needle leading operation is required, the operation is automatically performed. In addition, a function for executing a needle heading alternative operation is also provided.

The procedure at the time of executing the automatic needle heading alternative operation will be described in detail with reference to the flow chart of FIG.

First, in step S1201, a phenomenon that requires a needle head replacement operation, that is, a conveyance failure of the recording sheet medium in the saddle finisher during image formation, or a malfunction of the saddle stapler 512 (a), (b) itself. When the error occurs, the information is stored in the nonvolatile memory 403.
To record.

Next, in step S1202, when the operator instructs execution of any image forming process, it is determined whether the image forming process is an operation without saddle stitching operation. The image forming process is executed as usual.

On the other hand, if the image forming process accompanied by the saddle stitch operation is instructed, it is determined that it is necessary to execute the needle heading alternative operation prior to that, and the process proceeds to step S1204.
Move on to

In step S1204, the content of the nonvolatile memory 403 is used to refer to the information as to whether or not the current device needs to execute the needle leading alternative operation. If the information is recorded in the nonvolatile memory 403, Then, the flow shifts to S1205, in order to execute a needle heading alternative operation. If it is determined from the reference result of the recording in the non-volatile memory 403 that the execution of the needle leading replacement operation is not necessary, the image forming process is executed as usual in S1203.

In step S1205, it is determined whether or not the apparatus is in a state where a needle heading alternative operation is possible. This is because the staple head replacement operation involves conveyance of a staple head sheet medium in the printer unit and the staple finisher unit, and may not be executed depending on the state of the apparatus. For example, none of the sheet media that can be the sheet media for needle leading is set in any of the cassettes 340 and 341 and the manual feed unit 353 of the printer unit, or the connection between the printer unit and the staple finisher unit is not established. Such cases correspond to this. Therefore, in this case, the process proceeds to step S1206. In this embodiment, if the state of the printer unit and the staple finisher unit is in a state in which the needle heading alternative operation cannot be performed, the operator is notified to that effect and the needle heading is performed. A function is provided through the operation unit 402 to display a screen for prompting the operator to return to the apparatus so that the alternative operation can be performed. FIG. 1 shows an example of a screen interface on the operation unit 402 at that time.
3 is shown. As a result, the flow moves to 1207 when the device returns to a state where the needle heading alternative operation can be performed. Note that S
At step 1205, if there is no problem particularly in performing the needle heading alternative operation, it goes without saying that the processing shifts to step S1207.

In S1207, a needle heading alternative operation is executed. Since the operation has been described in detail above, it is omitted here.

In S1208, in response to the completion of the needle heading alternative operation, the recording in the nonvolatile memory 403 indicating that the needle heading operation is necessary is deleted. After that, the flow shifts to S1203 to execute the image forming operation as instructed by the operator in S1202. Thereafter, if a phenomenon that requires the needle heading alternative operation occurs again, S1
The flow returns to 201, but if not, the processing from S1202 onward is repeated.

The initial value of the information in the nonvolatile memory 403 as to whether or not it is necessary to execute the needle leading-substituting operation is described below.
When the needle cartridge 701 is set in (a) and (b), the needle plate is not mounted on the needle plate transport guide portion 703 at all. Therefore, it can be said that a needle head replacement operation is required. Therefore, in the present embodiment, the initial value of the information as to whether or not it is necessary to execute the needle-pointing alternative operation in the nonvolatile memory 403 is set in advance to the content indicating that the needle-pointing alternative operation needs to be executed. . By doing so, it is assured that the needle head can be reliably set even when the saddle stitch operation is executed in the image forming apparatus in the present embodiment for the first time.

As described above, in the present embodiment, in order to realize the same operation as the staple cueing processing without having a special staple cueing mechanism, a sheet medium bundle which is supposed to be stapled is originally required. Instead, the normal stapling operation is performed once or more than once on one or more sheet media dedicated to performing the needle cueing, thereby performing the needle cueing alternative processing, thereby achieving a cheaper configuration. When necessary, it is possible to execute a cueing operation.

In this embodiment, the operator can issue an instruction to execute the needle cueing alternative processing asynchronously, and in that case, notifies the operator of the necessity of the cueing processing and warns the operator. Or, if the cueing alternative processing is not executed, by prohibiting the execution of the sheet medium transport operation accompanied by the execution of the next staple driving processing, it is possible to execute the staple cueing alternative processing in a situation where the cueing is required. did.

Further, in the present embodiment, the apparatus detects a situation in which the needle leading is required and the needle leading alternative processing can be executed, and if necessary, involves the execution of the next staple needle driving processing. This makes it possible to automatically execute the needle leading alternative operation immediately before the sheet medium conveying operation.

Further, in the present embodiment, the fact that the stylus is required or not is stored in the non-volatile memory, and even if the apparatus power is turned off / on, the next staple stapling process is surely performed. It is possible to execute the staple leading alternative operation before the execution of the sheet medium transport operation accompanied by the execution.

Further, in the present embodiment, it is stored in advance in the nonvolatile memory that the stapling of the staples is impossible as an initial value of the information on whether or not the stapling of the staples is impossible. By doing so, it is possible to always perform the staple leading alternative operation even when the sheet medium transporting operation involving the execution of the staple staple driving process is executed for the first time as the sheet medium transporting device.

(Modification of Embodiment) The above embodiment is an example relating to the conveyance of a recording sheet medium in an image forming apparatus. However, the present invention is not limited to the image forming apparatus but may be applied to a conveying apparatus which involves a stapling operation for other sheet media. Of course, the same configuration and function can be applied.

In the above-described embodiment, a stapler capable of automatic needle cueing will be described together with the conventional stapler. Therefore, a configuration in which a needle cueing alternative operation is required only for the saddle staplers 512 (a) and (b) is adopted. The end stapler 507 is configured to be a conventional stapler capable of automatic needle cueing. Of course, the end stapler 507 also has a saddle stapler 512 (a),
(B) Similarly, it is possible to adopt a configuration that requires a needle head replacement operation.

In the above-described embodiment, it is necessary to execute the needle heading alternative operation when the conveyance of the recording sheet medium in the saddle finisher during image formation or the saddle stapler 512 (a) or (b) itself is performed. It is limited to the case where an operation failure occurs, and it is not necessary in the device configuration when a needle is missing. Of course, if the device configuration requires the same operation to be performed without a needle, the same applies to the needle head. It is also possible to execute the output substitution operation.

In the above-described embodiment, a configuration is adopted in which both a normal recording sheet medium and a sheet medium for locating the needle are used. It may be.

In the above-described embodiment, the sheet medium transport path leading to the saddle stitch tray 511 for performing the normal image forming operation and the staple leading-out alternative operation is common, but of course each operation is performed separately. May be independent.

In the above-described embodiment, the explanation has been given assuming that the operator has both the function of instructing the needle head replacement operation by the operator and the function of automatically executing the operation. However, the final operation results are the same. Alternatively, a configuration having only one of the functions may be employed.

[0088]

As described above, according to the present invention,
An operation equivalent to the needle cueing process can be realized without a special needle cueing mechanism, and the apparatus can be reduced in size and cost.

More specifically, according to the first to sixteenth aspects of the present invention, a sheet medium which is supposed to be stapled in order to realize the same operation as the staple cueing processing without having a special staple cueing mechanism. By performing the normal stapling operation one or more times on one or a plurality of sheet media dedicated to performing the cueing of a needle, instead of on a bundle, and thereby performing the cueing alternative processing of the staples. When necessary, a cueing operation can be performed with an inexpensive configuration.

According to the fourth aspect of the present invention, the operator can issue an instruction to execute the needle heading alternative processing asynchronously. In the fifth aspect of the present invention, it is necessary to execute the head positioning processing. In the invention according to the sixth aspect, the execution of the sheet feeding operation accompanied by the execution of the next staple driving process is prohibited unless the cueing alternative process is executed, so that the cueing of the staple is reliably performed. Can be executed in a situation where the above is necessary.

Further, according to the present invention, the apparatus detects a situation in which it is necessary to perform the stapling operation, and can execute the stapling alternative processing, and if necessary, executes the next staple stapling processing. Immediately before the sheet medium conveying operation accompanied by the above, the needle leading alternative operation can be automatically executed.

According to the twelfth aspect of the present invention, it is stored in the non-volatile memory that the stylus is required or not, so that the next stapling stapling can be reliably performed even when the power supply of the apparatus is turned off / on. It is possible to execute the staple leading-out alternative operation before the sheet medium transport operation accompanying the execution of the process is executed.

According to the thirteenth aspect of the present invention, the stapling of the staples cannot be previously performed as an initial value of the information regarding whether or not the stapling of the staples stored in the storage means in the nonvolatile memory is disabled. When the sheet medium transport operation involving execution of the staple stapling process is executed for the first time as the sheet medium transport device, the staple leading alternative operation can always be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a digital image processing unit.

FIG. 2 is a block diagram illustrating a configuration of a printer processing unit.

FIG. 3 is a diagram showing the overall configuration of an embodiment.

FIG. 4 is a block diagram showing a configuration of a control unit.

FIG. 5 is a diagram showing a configuration of a staple finisher unit;

FIG. 6 is a view showing a configuration of an end stapler and a needle driving operation;

FIG. 7 is a diagram showing a configuration of a saddle stapler;

FIG. 8 is a flowchart showing a process of a needle heading alternative operation.

FIG. 9 is a diagram showing a screen for instructing the start of a needle leading alternative operation.

FIG. 10 is a diagram showing a screen indicating that a needle head positioning alternative operation is necessary.

FIG. 11 is a diagram showing a screen indicating that a needle leading alternative operation is necessary.

FIG. 12 is a flowchart showing a process performed when executing an automatic needle cueing alternative operation.

FIG. 13 is a diagram showing a screen for urging the user to return to the apparatus so that the needle leading alternative operation can be executed.

[Description of sign]

 401 CPU 504 Conveyance roller 505 Staple tray 508 Paper discharge roller 512 Side stapler

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/00 378 G03G 21/00 386 386 500 500 B41J 29/00 HF term (Reference) 2C061 AQ06 AS02 BB33 CK04 2H027 DC17 DD00 ED29 EF06 EH06 EK03 FA21 FA35 FB06 FB07 FB19 GA20 GA23 GB08 GB09 HA20 3C054 CB04 CC06 CD05 CF11 CF18 3F108 GA02 HA02 HA33

Claims (16)

[Claims] 1. A sheet medium transport means for continuously transporting a plurality of sheet media, and a sheet medium bundle temporarily staying a sheet medium bundle in which a plurality of sheet media transported by the sheet medium transport means are stacked. Means, a staple means for performing a staple driving process on the sheet medium bundle temporarily staying in the sheet medium bundle temporary staying means, and a sheet medium bundle on which staple driving operation is performed by the staple means And a discharge unit for discharging the sheet outside the apparatus. The stapling process is performed in a sheet medium bundle unit in which a plurality of sheet media conveyed to the sheet medium bundle temporary staying unit by the sheet medium conveyance unit are stacked. A sheet medium transport device that can be later ejected out of the apparatus, wherein the staple means is incapable of driving a staple. In the case where there is no special means for executing the needle leading operation for returning to the state where the next needle driving operation can be executed in the situation, at least one staple needle leading sheet medium is placed in the sheet medium bundle. A control means for executing, as a needle heading alternative operation, performing the staple driving process by the staple means once or a plurality of times on the staple needle heading sheet medium after being conveyed to the temporary holding means. Characteristic sheet medium transport device. 2. The sheet medium transporting device according to claim 1, wherein the state in which the staples cannot be driven is performed after a staple supply without a staple is performed or a sheet medium conveyance failure during the staple driving process. A sheet medium transport device, which is after a return process or both. 3. The sheet medium transport apparatus according to claim 1, wherein the staple staple cueing sheet medium is also used as a normally conveyed sheet medium. 4. The sheet medium transporting device according to claim 1, further comprising an instruction unit for instructing an operator to start the needle head replacement operation, and the needle head being instructed by the instruction unit. A sheet medium transporting device that performs a feeding alternative operation. 5. The sheet medium transporting device according to claim 4, further comprising: a notification and a warning unit for notifying and warning an operator that execution of the needle heading alternative operation is necessary. Sheet media transport device. 6. A sheet feeding apparatus according to claim 4, wherein said stapling means determines whether or not a stapling alternative operation is necessary. Conditional processing prohibiting means for prohibiting a sheet medium conveyance operation accompanied by execution of a staple stapling process is provided. A sheet-medium conveying device for prohibiting execution of the sheet-medium conveying operation accompanied by execution of the staple-staple-insertion process until the staple-heading alternative operation is instructed and executed. 7. The sheet feeding device according to claim 1, further comprising: a stylus head alternative operation determining unit that determines that the apparatus is in a state where the stapling alternative operation can be performed. Only when the stapling of the staple is impossible and when it is determined that the alternative needle locating operation is executable by the alternative needle locating operation determining means, the alternative needle locating operation is performed. A sheet medium conveying device characterized by the above-mentioned. 8. The sheet medium transporting device according to claim 7, wherein at least one sheet of the staple staple leading-out sheet medium is set in the sheet medium transporting device as a device state in which the staple leading-out alternative operation can be executed. A sheet medium conveying device, wherein the sheet medium can be conveyed by a medium bundle temporary staying means. 9. The sheet medium transporting device according to claim 7, further comprising a needle heading alternative operation automatic start means capable of automatically starting the needle heading alternative operation, wherein a staple needle cannot be driven. Under the circumstances, and when it is determined by the needle heading alternative operation possible determination means that the needle heading alternative operation can be executed, the needle heading alternative operation is automatically started and executed. Sheet medium transport device. 10. The sheet medium transporting device according to claim 9, wherein the automatic start and execution of the staple leading alternative operation by the staple leading alternative operation automatic start means involves execution of the next staple staple driving process. A sheet medium conveying device immediately before a conveying operation. 11. The sheet medium transport device according to claim 1, wherein said sheet medium transport device has a non-volatile storage means for storing that stapling of said staple is impossible. It is referred to at any time whether or not the driving of the staples stored in the storage means is impossible, and according to the result, it is determined whether or not the driving of the sheet medium transport device is in the state where the driving of the staples is impossible. A sheet medium transport device for making a determination. 12. The sheet medium transport device according to claim 11, wherein the non-volatile storage means makes it impossible for the sheet medium transport device to drive a staple even after the power of the sheet medium transport device is turned off. A sheet medium conveying device capable of storing whether or not the sheet medium is present in the sheet medium. 13. The sheet medium transporting device according to claim 11, wherein the staple driving is disabled beforehand as an initial value of the information on whether or not the staple driving is stored in the storage means. By stating that there is, even when the sheet medium transporting operation accompanied by the execution of the staple driving process is executed for the first time by the sheet medium transporting device, the staple leading alternative operation is always performed. A sheet medium conveying device characterized by the above-mentioned. 14. An image forming apparatus comprising the sheet medium conveying device according to claim 1. Description: 15. A step A in which it is determined whether or not a needle heading alternative operation is necessary.
Step B for determining whether or not the needle heading alternative operation can be executed; and
A step C of performing a needle heading alternative operation. 16. The needle cueing processing method according to claim 15, wherein the needle cueing alternative operation is an operation of repeating a required number of times of stitching out on a sheet medium for cueing.