JP5336316B2 - Sheet stacking apparatus, post-processing apparatus including the same, and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet stacking device which registers a sheet carried out onto a tray from a paper ejecting port in the accurate position. <P>SOLUTION: A paper ejecting reference position Fk of the sheet carried out onto the tray from the paper ejecting port is made different in the paper orthogonal direction (by dislocating a position) in the side edge of the sheet by a predetermined quantity from a registering reference position Sk of the sheet registered on the tray, to form an offset area. A sheet end detecting means Se for detecting the edge of the sheet toward a regulating position on the tray from the paper ejecting port 24, is arranged within this offset area. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a post-processing apparatus that performs post-processing such as paper binding on a sheet transported from an image forming apparatus such as a copying machine or a printer, and a sheet aligning mechanism that aligns the sheet transported on a tray to a predetermined position. Regarding improvements.

  In general, this type of sheet stacking device is widely known as a device that stacks sheets sent from a paper discharge path on a tray, and is used, for example, as a device for stacking and stacking sheets sent from an image forming apparatus in a post-processing device. Has been. The post-processing apparatus is known as an apparatus that performs a binding process, a punching process, and the like on a sheet bundle that is arranged and collected on a tray.

  Conventionally, in such an apparatus, a processing tray is disposed downstream of the sheet discharge outlet, a stack tray is disposed downstream of the processing tray, and a sheet (bundle) post-processed by the processing tray is stored in the stack tray. Are known. For example, in Patent Document 1, a processing tray is disposed on the downstream side of the sheet discharge outlet and a processing tray is disposed on the downstream side. A structure is disclosed in which the front end portion is supported by a stack tray and the rear end portion of the sheet is supported by a processing tray (bridge support).

  In such an apparatus, the sheet edge in the sheet width direction is positioned at a predetermined position at the same time as the sheet edge is positioned at a predetermined restriction position while the sheet carried out from the sheet discharge port is bridge-supported between the two trays. Need to be done. For this reason, in Patent Document 1, a roller that can be raised and lowered is provided above the processing tray, and after the leading end of the sheet reaches the stack tray from the sheet discharge port, the roller is lowered from the upper retracted position to an operating position that contacts the sheet. Yes. The roller is rotated in the direction opposite to the paper discharge direction, and the trailing edge of the sheet carried out from the paper discharge port is abutted and aligned with the restriction stopper. At the same time, the tray is provided with an alignment mechanism for aligning the sheet side edge with the reference position.

  Conventionally, when a sheet is carried out from a sheet discharge port to a tray having a step, a sheet discharge rotator such as a roller and a belt is provided on the tray so as to be movable up and down. At the timing of passing, the sheet moves from the retracted position to an operating position that engages with the sheet, and the sheet is abutted against the restriction stopper by the conveying force of the rotating body. In this case, the sheet discharge rotator is lowered to the operating position at the expected time when the rear end of the sheet passes through the sheet discharge port and is carried onto the tray based on the signal from the sheet detection sensor.

JP 2006-248686 A

  As described above, in the sheet stacking structure in which the sheet sent to the sheet discharge path is carried out from the sheet discharge outlet onto the tray and is placed against the restriction stopper by the sheet discharge rotating body arranged on the tray, the following problem is caused. There is. When a sheet from the sheet discharge port is carried into the sheet discharge rotator on the tray, the sheet unloaded from the sheet discharge port may not enter between the storage sheet and the roller on the tray. , Leading to breakage of the tip.

  For this reason, a roller (paper discharge rotator) disposed on the tray employs a lifting mechanism that moves up and down between a retracted position above the tray and an operating position on the tray. Adoption of such a mechanism causes the following new problem. In other words, when the leading edge position of the sheet carried out from the sheet discharge port and the timing at which the roller moves from the standby position to the operating position deviates back and forth, the sheet conveyance timing at which the sheet edge (rear edge or leading edge) abuts the regulation stopper. Will be crazy. As a result, the sheet end overruns at the stopper position (over the stopper), the leading edge is bent, or the stopper position is not reached.

  Such sheet alignment defects occur frequently as the sheet material is diversified, such as coated paper, OHP paper, thin paper, and thick paper. Misalignment of the sheets stacked on the processing tray occurs after binding processing, punching processing, and the like. The problem is that the processing quality is extremely deteriorated.

  In view of this, the present inventor examined the cause of unevenness when positioning the sheet carried out from the sheet discharge port onto the tray at a predetermined position, and on the processing tray, a conveying body (for transferring the sheet to the restriction stopper) One or a plurality of conveyance rollers, paddles, etc.) are necessary, and these conveyance bodies need to be engaged with the sheet or impart conveyance force in accordance with the timing of the sheet that has entered the tray. In particular, the sheet discharged from the paper discharge port onto the tray is free-falling, and it has been determined that the dropping position differs significantly depending on the properties of the sheet.

  Conventionally, however, a sensor that detects the sheet edge is arranged in the paper discharge path on the upstream side of the tray, and the rollers, alignment means, etc. on the tray are controlled by the estimated time based on the detection signal. After finding out that it was difficult, we came up with the idea of detecting the leading or trailing edge of the sheet on the tray.

An object of the present invention is to provide a sheet stacking apparatus capable of aligning a sheet conveyed from a sheet discharge port onto a tray at an accurate position.
Another object of the present invention is to provide a sheet stacking apparatus capable of accurately detecting the edge of the sheet carried out from the sheet discharge port onto the tray with a simple structure by distinguishing from the already stacked sheets. It is said.

  In order to achieve the above object, according to the present invention, a sheet discharge reference position of a sheet transported from a sheet discharge outlet onto a tray and an alignment reference position of a sheet aligned on the tray are set. Are offset by a predetermined amount (displaced) to form an offset region. The sheet edge detecting means for detecting the edge of the sheet from the sheet discharge outlet toward the restriction position on the tray is arranged in the offset area.

  Further, the configuration will be described in detail. A sheet discharge path (P1) provided with a carry-out means (26) for sequentially carrying out the sheets from the sheet discharge outlet, and a tray means for stacking the sheets arranged on the downstream side of the sheet discharge outlet. (29), a sheet end regulating means (30) for regulating the edge of the sheet carried out to the tray means, and a sheet discharge rotating body (30) for transferring the sheet carried on the tray means toward the sheet end regulating means. 31, 35), an elevating support means (35 a) that supports the sheet discharge rotator so as to be movable up and down between an operating position in contact with the sheet on the tray means and a retracted position separated from the sheet, and on the tray means Alignment means (37) for aligning the side edge of the stored sheet in the sheet discharge orthogonal direction to the reference position, and lift drive means (MS) for raising and lowering the discharge rotating body between the operating position and the retracted position, and alignment Alignment drive means (Ma, Mb) for operating the means Comprises sheet end detecting means for detecting the edge of the sheet from the sheet discharge port and (Se), control means for controlling the lifting drive means based on a detection signal of the sheet end detecting means (50).

  The discharge reference position (Fk) of the carry-out means (26) and the alignment reference position (Sk) of the alignment means (37) are the side edge of the sheet carried out from the discharge outlet onto the tray means, and the tray means Are set so as to form an offset region by making a predetermined amount different from the side edge of the sheet to be aligned in the direction perpendicular to the sheet discharge. The sheet edge detecting means (Se) is disposed at a position for detecting the edge of the sheet from the sheet discharge outlet to the sheet edge regulating means (30) within the offset area on the tray means (29).

  In the present invention, an offset area is provided by shifting the sheet carried out from the sheet discharge outlet onto the tray and the sheet accumulated on the tray in the direction perpendicular to the sheet discharge, and the leading edge or the trailing edge of the sheet is provided in the offset area. Since the sheet edge detecting means for detecting is arranged, the following effects are obtained.

  The sheet carried out from the sheet discharge port is transferred to a predetermined sheet end regulation position by a sheet discharge rotating body on the tray. At this time, the timing for shifting the paper discharge rotator from the retracted position to the operating position is assured and accurate sheet discharge without losing the timing by arranging the sheet end detection means at the position of the paper discharge rotator on the tray. Can be sent in the direction opposite to the paper discharge direction.

  Further, when the sheet carried on the tray is brought into contact with the sheet end regulation position and aligned, overrun by detecting the edge immediately before the leading end of the sheet reaches the edge stopper also causes the leading end to bend. It is rare that it will be unreachable.

  Further, the present invention provides a mechanism for offsetting the sheet carried out on the tray and the sheets stacked on the tray in the direction perpendicular to the sheet discharge, and aligning the sheet side edges arranged on the processing tray by aligning and aligning. It is only necessary to shift the reference position by a predetermined amount from the sheet discharge reference position of the sheet discharge port, and the simple structure can be provided at low cost.

  Further, the sheet edge detecting means arranged on the tray is composed of a movable aligning member that moves the aligning means arranged on the tray in the direction perpendicular to the sheet discharge, and a plurality of sizes of sheets are arranged by arranging sensors on the movable aligning member. The edge can be provided at a low cost with a simple structure.

1 is an explanatory diagram of an overall configuration of an image forming system according to the present invention. FIG. FIG. 2 is an explanatory diagram illustrating a configuration of a sheet stacking apparatus in the system of FIG. 1. FIG. 3 is an explanatory perspective view illustrating a conceptual configuration of the sheet stacking apparatus of FIG. 2. FIG. 3 is an explanatory diagram of an aspect in which an offset region is formed between a sheet carry-out reference and an alignment reference in the sheet stacking apparatus of FIG. 2, and (a) illustrates a case where the carry-out reference and the alignment reference are misaligned in parallel; ) Shows the cases where the angle and orientation of the carry-out standard and the alignment standard are different. FIG. 3 is an explanatory diagram illustrating details of a structure in which an offset region is formed by shifting a sheet carry-out reference and an alignment reference in parallel in the sheet stacking apparatus of FIG. 2. FIGS. 6A and 6B are explanatory views showing the configuration of the sheet aligning means in the embodiment of FIG. 5, where FIG. 5A shows the alignment mechanism, FIG. FIG. 3 is an explanatory diagram illustrating details of a structure in which an offset region is formed by changing an angle posture of a sheet carry-out reference and an alignment reference in the sheet stacking apparatus of FIG. 2. Explanatory drawing which shows the whole structure of the post-processing apparatus in the system of FIG. FIG. 9 is a detailed explanatory diagram of a paper discharge mechanism in the apparatus of FIG. 8. FIG. 2 is a block diagram showing a control configuration in the image forming system of FIG. 1.

The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 shows an image forming system according to the present invention. After an image forming apparatus A for forming an image on a sheet and sheets conveyed from the image forming apparatus A are collected and subjected to post-processing such as binding processing. It comprises a processing apparatus B and a sheet stacking apparatus C built in the post-processing apparatus B. Then, the sheets formed by the image forming apparatus A are stacked and stacked by the sheet stacking apparatus C, and the sheet bundle is subjected to binding processing and stored in the stack tray 21.
Hereinafter, “sheet stacking apparatus C”, “image forming apparatus A”, and “post-processing apparatus B” will be described in this order.

[Sheet Accumulator]
The sheet stacking apparatus C according to the present invention is provided with a sheet discharge path P1 for sequentially carrying out the sheets as shown in FIG. In the paper discharge path P1, a carry-in port 23, a paper discharge port 24, and a carry-out means 26 are arranged. The apparatus shown in FIG. 2 is disposed in the apparatus housing 20 so that a sheet discharge path P1 having a carry-in port 23 and a discharge port 24 crosses the apparatus, and the carry-in port 23 is a main body discharge port of the image forming apparatus A described later. 15 is carried into the apparatus. Further, a step is formed in the paper discharge port 24, and a tray unit (hereinafter referred to as “processing tray”) 29 is disposed on the downstream side, and a stack tray 21 is disposed on the downstream side of the tray unit 29.

  The processing tray 29 aligns and stacks the sheets from the paper discharge outlet 24 and performs a binding process (post-processing). For this reason, the processing tray 29 includes sheet end regulating means (hereinafter referred to as “regulation stopper”) 30 for regulating the position of the edge in the sheet ejection direction, and sheet ejection rotators 31 and 35 for transferring the sheet to the regulation stopper 30. Is arranged. The illustrated sheet discharge rotators 31 and 35 include a forward / reverse roller 35 and a scraping belt 31.

  The sheet discharge rotators 31 and 35 are arranged so as to engage with the sheet carried on the processing tray and transfer it to the restriction stopper 30. At the same time, the forward / reverse roller 35 is supported by the apparatus frame so as to be movable up and down between an operating position Fp in contact with the uppermost sheet on the processing tray and a retracted position Tp separated from the sheet. This is because the leading edge of the sheet carried out from the paper discharge port 24 is surely entered between the forward / reverse roller 35 and the uppermost sheet. Further, the above-described scraping belt 31 is not limited to a belt, and may be composed of a paddle member, a roller, or the like.

  As shown in FIG. 2, the forward / reverse roller 35 is supported by a bracket 35a whose base end is swingably supported on an apparatus frame (not shown), and is provided above the processing tray 29 so as to be vertically swingable. ing. A drive pulley is provided at the base end of the bracket 35a, and a forward / reverse motor M1 (see FIG. 9) is connected to the pulley. At the same time, a shift motor MS (not shown) is connected to the base end portion of the bracket 35a to swing the bracket 35a by a predetermined angle. Accordingly, the forward / reverse roller 35 moves up and down between the retracted position Tp and the operating position Fp by the forward / reverse rotation of the shift motor (elevating drive means) MS, and is rotated in the predetermined sheet transfer direction by the forward / reverse motor M1. .

  Further, the processing tray 29 is arranged such that the sheets stacked and aligned on the tray are abutted against the restriction stopper 30 to position the leading edge or the trailing edge, and at the same time, the sheet conveyance orthogonal direction is set to a predetermined reference position. Alignment means 37 is provided to match the above. Although the details of the aligning means 37 will be described later, sheets of different width sizes are arranged so as to be width-aligned and aligned based on the center reference or the side reference. As will be described later, the aligning unit 37 sets the “alignment reference position Sk” based on the center reference or the side reference, and aligns the sheets to the alignment reference position Sk.

  On the other hand, the carry-out means 26 arranged in the paper discharge path P1 is configured by pressing a pair of roller units each having a plurality of rollers arranged on the drive shaft 26x at predetermined intervals as shown in FIG. The carry-out means 26 configured as described above sets the “paper discharge reference position Fk” so that when a sheet is transferred from the carry-in port 23 to the paper discharge port 24, sheets having different width sizes are carried out based on the center reference or the side reference. Is set. Normally, the paper discharge reference position Fk is set to coincide with the sheet conveyance reference of the image forming apparatus A located on the upstream side.

  Accordingly, in the present invention, the sheet carried out from the paper discharge port 24 onto the processing tray is transferred to the restriction stopper 30 by the forward / reverse roller 35. At this time, an alignment operation is performed so that the leading end of the sheet is guided to the stopper side by the sheet discharge rotator (rake belt) 31. This alignment operation includes an elevating operation for lowering the forward / reverse roller 35 from the retracted position Tp to the operating position Fp, and a conveying operation for applying a conveying force to the sheet loaded with the rotation of the forward / reverse roller 35.

  Then, the movement timing from the retracted position Tp of the forward / reverse rotation roller 35 to the operating position Fp and / or the timing of applying conveyance force (start of conveyance and conveyance stop) to the sheet loaded on the processing tray by the rotation of the normal / reverse rotation roller 35. Is performed as follows. Therefore, the next offset mechanism and the sheet end detection means Se are arranged in the paper discharge path P1 or the processing tray 29.

[Offset mechanism]
First, the discharge reference position Fk of the carry-out means 26 and the alignment reference position Sk of the aligning means 37 are aligned on the processing tray with the side edge of the sheet carried out from the discharge outlet 24 onto the process tray. The offset region Of is formed by varying the side edge of the sheet by a predetermined amount (Δy) in the sheet discharge orthogonal direction (Y direction in FIG. 3).

  The configuration is as follows: (1) The alignment reference position Sk of the alignment means 37 for shifting the sheet fed from the paper discharge path P1 in the processing tray 29 in the conveyance orthogonal direction is shifted by a distance Δy (FIG. 4A )) Or (2) the paper discharge reference position Fk of the unloading means 26 in the paper discharge path P1 is shifted by the distance Δy, or (3) the paper discharge reference position Fk of the sheet carried out in the paper discharge path P1 is set. Whether the carry-out sheet and the stacked sheet are displaced by a predetermined amount Δy by inclining by a predetermined angle (α angle) (see FIG. 7), or (4) the sheets carried in the processing tray 29 are aligned in the widthwise direction in the conveyance orthogonal direction. In this case, the alignment reference position Sk is inclined by a predetermined angle (α angle) and the loaded sheets and the stacked sheets are displaced by a predetermined amount Δy (see FIG. 4B). Adopt the method.

  3, FIG. 4 (a) and FIG. 5 show the case where the offset region Of is formed by shifting the alignment reference position Sk of the above (1) by the distance Δy as the first embodiment, and FIG. As the second embodiment, the case where the offset region Of is formed by inclining the sheet discharge reference position Fk of the sheet carried out in the sheet discharge path P1 of (3) above by a predetermined angle (α angle) is shown.

[First Embodiment of Offset Mechanism]
The apparatus shown in FIGS. 4A and 5 shows a case in which the offset area Of is formed by translating a sheet carried into the processing tray 29 from the paper discharge path P1 by a predetermined amount Δy in the conveyance orthogonal direction. . Therefore, as shown in FIG. 3, a pair of left and right alignment members 37a and 37b are supported on the processing tray 29 by an apparatus frame (not shown) so as to be movable in the direction perpendicular to the paper discharge. The left and right alignment members 37a and 37b are formed so that the side guide surfaces protrude above the tray, and the left and right alignment members 37a and 37b extend along the guide grooves 29x formed on the paper loading surface of the processing tray 29. It moves in the direction perpendicular to the paper discharge.

  In addition, the processing tray 29 is provided with alignment motors Ma and Mb, which are independent from each other on the left and right sides of the apparatus frame, as shown in FIG. 6 (a), and a drive belt 39 spanning a pair of pulleys 38a and 38b. A pair of left and right alignment members 37a and 37b are connected. Accordingly, the pair of left and right alignment members 37a and 37b move left and right along the guide groove 29x, and the alignment motors Ma and Mb rotate by the same amount in the opposite direction.

  Further, the pair of left and right alignment members 37a and 37b is provided with a limit sensor 37y that detects the home position. Therefore, the control means (not shown) controls the alignment motors Ma and Mb so that the pair of left and right alignment members 37a and 37b reciprocate in the order from the home position Hp to the standby position Wp and the alignment position Ap. At this time, the standby position Wp and the alignment position Ap are set according to sheets having different width sizes. A detection position Dp described later is set between the standby position Wp and the alignment position Ap.

  The aligning means 37 configured as described above has its alignment reference position Sk (shown in the case of the center reference) shifted by Δy from the discharge reference position Fk set in the discharge path P1. It is set to be. As a result, as shown in FIG. 4A, an offset region Of is formed between the edge She of the sheet carried out from the paper discharge path P1 and the edge Ste of the stacked sheets aligned on the processing tray. Therefore, the sheet carried out from the paper discharge path P1 is carried out with a positional deviation of Δy from the sheets already stacked on the processing tray.

[Sheet edge detection means]
In the offset area Of, sheet edge detection means Se for detecting the leading edge or trailing edge of the sheet from the sheet discharge outlet 24 is disposed. This detection means Se is disposed, for example, on one of the alignment members 37a and 37b described above. The apparatus shown in FIG. 3 is composed of a reflective photosensor in which a light emitting element and a light receiving element are opposed to a left alignment member 37b. In addition, the sheet edge detecting means Se may be constituted by a transmissive photosensor in which a light emitting element and a light receiving element are arranged to face each other above the processing tray 29 and the sheet discharge outlet. Therefore, the present invention is characterized in that the sheet edge detecting means Se is disposed in the offset region Of at a position for detecting the edge (leading edge or trailing edge) of the sheet from the sheet discharge outlet 24 to the restriction stopper 30.

  The sheet end detection means Se is configured as a timing sensor for lowering the forward / reverse rotation roller 35 from the retracted position Tp to the operating position Fp. A transmissive photosensor is used to detect the rear edge.

  Further, when the sheet end detection means Se is configured as a timing sensor for stopping the forward / reverse rotation roller 35, the sheet loaded on the processing tray is transferred toward the restriction stopper 30 by the forward / reverse rotation roller 35, and the sheet edge ( In the illustrated case, the forward / reverse roller 35 is stopped after the rear edge of the paper discharge direction) abuts against the restriction stopper 30. In this case, it is preferable that the sheet end detection means Se is constituted by a reflection type photosensor.

[Second Embodiment of Offset Mechanism]
FIG. 7 shows a case where the offset area Of is formed by rotating a sheet carried out from the paper discharge path P1 onto the processing tray by a predetermined angle. Similar to the above, the discharge means 26 is disposed in the paper discharge path P1, and the processing tray 29 and the alignment means 37 are disposed on the downstream side thereof. Therefore, the carry-out means 26 has a plurality of rollers arranged on the drive shaft 26x at predetermined intervals. By inclining the drive shaft 26x and the roller by an angle α, the sheet carried in from the paper discharge port 24 with respect to the sheets stacked and aligned on the processing tray is inclined by the angle α and placed between the stacked sheets. An offset region Of is formed by Δy. In the offset area Of, the same sheet edge detection means Se as described above is arranged.

[Configuration of Image Forming Apparatus]
The image forming apparatus A includes a paper feeding unit 2, an image forming unit 3, and an image data storage unit in a casing 1. The sheet feeding unit 2 is composed of, for example, a plurality of sheet feeding cassettes 2a, 2b, 2c, and 2d, and pre-selected standard size sheets are stored in the cassettes 2a to 2d. The paper feed unit 2 is provided with a manual feed tray 1x so that the user can insert sheets according to the purpose of use. A sheet set in the sheet feeding unit 2 having such a configuration has a sheet condition such as its size, paper quality (coating paper or plain paper), paper thickness (thick paper or thin paper), and the control panel 16 described later. It is configured to input information from.

  The image forming unit 3 is configured to form an image on a sheet sent from the paper feeding unit 2, and the illustrated one shows an electrostatic image forming mechanism. The image forming unit 3 is provided with a photosensitive drum 10, a print head (a light emitting device such as a laser beam or LED light) 9 for forming a latent image on the drum surface, and a developing device 11. The image ink (toner) formed on the photosensitive drum 10 is image-transferred by the transfer charger 12.

  The sheet on which the image has been transferred in this manner is carried out to the paper discharge path 14 via the fixing roller 13. In addition, the image forming unit 3 is not limited to the illustrated electrostatic image forming mechanism, and various image forming mechanisms such as an ink jet image forming mechanism and an offset image forming mechanism can be employed.

  Although not shown, the image data storage unit is configured by a storage memory for image data formed on the photosensitive drum 10 by the print head 9 of the image forming unit 3 so that data can be transferred from the image reading unit 5 to the storage unit. It has become. Data is also transferred to the image data storage unit from, for example, a networked computer.

  In the image forming apparatus A configured as described above, an image reading unit 5 for reading a document image is mounted on the upper portion thereof, and a document feeding unit 8 is further mounted on the upper portion thereof. The image reading unit 5 includes a platen 5a for setting an original sheet, a reading carriage 6 for scanning an original image along the platen 5a, and a photoelectric conversion means 7 for forming an image of reflected light from the original image and performing photoelectric conversion. Is provided inside. The document feeding unit 8 includes a feeder mechanism that separates document sheets set on the sheet feeding tray 8a one by one and automatically feeds them to the platen 5a of the image reading unit 5.

[Configuration of post-processing equipment]
The post-processing apparatus B connected to the image forming apparatus A will be described. As shown in FIG. 1 and the detailed configuration in FIG. I have. The processing tray 29 described above is disposed downstream of the paper discharge port 24. The discharge means 26 (hereinafter referred to as “discharge roller”) is disposed in the sheet discharge path P1, and the forward / reverse rotation roller 35 and the alignment means 37 are disposed in the processing tray 29. Hereinafter, a configuration different from the above will be described.

  The post-processing apparatus B receives a sheet on which an image has been formed from the main body discharge port 15 of the image forming apparatus A, and (1) accommodates the sheet in the stack tray 21 without performing post-processing (described later in “Print”). Out mode "), or (2) after aligning the sheets from the main body discharge port 15 into a bundle and stapling them, and then storing them in the stack tray 21 (" stapling mode "described later)) or ( 3) After the sheets from the main body discharge port 15 are arranged in a bundle, the sheets are folded into a booklet and stored in the booklet storage tray 22 (a “sheet bundle folding mode” described later).

  For this reason, the post-processing apparatus B is provided with a paper discharge path P1 in the apparatus housing 20 as shown in FIG. A first switchback conveyance path SP1 and a second switchback conveyance path SP2 are arranged in the paper discharge path P1 and branch from now on to transfer the sheet in the reverse direction. The first switchback transport path SP1 is disposed on the downstream side of the paper discharge path P1, and the second switchback transport path SP2 is disposed on the upstream side of the carry-in first switchback transport path SP1.

  The processing tray 29 described above is disposed on the downstream side of the first switchback transport path SP1, and the stack tray 21 is connected to the downstream side thereof. A stacking tray 40 is disposed on the downstream side of the second switchback transport path SP2, and a booklet storage tray 22 is disposed on the downstream side thereof. Further, in the paper discharge path P1, a carry-in roller 25 that conveys the sheet from the carry-in port 23 toward the paper discharge port 24, and post-processing that performs post-processing such as stamping (stamping means) and punching (punching means) on the sheet. A unit 32 is provided.

[Configuration of the first switchback transport path SP1]
As described above, the first switchback conveyance path SP1 disposed on the downstream side (rear end portion of the apparatus) of the sheet carry-in path P1 is configured as follows. The paper discharge path P1 is provided with a paper discharge roller (the aforementioned carry-out means) 26 and a paper discharge port 24 at the exit end thereof, and a step is formed with the paper discharge port 24 and the above-described processing tray 29 is provided on the downstream side. It has been. The processing tray 29 is a tray that stacks and supports sheets from the sheet discharge outlet 24.

  Above the processing tray 29, the forward / reverse roller 35 is disposed so as to be movable up and down between an operating position Fp in contact with the sheet on the tray and a retracted position Tp (a chain line position in FIG. 2). A forward / reverse motor M1 is connected to the forward / reverse roller 35 and rotates clockwise when a sheet enters the processing tray 29, and rotates counterclockwise after the trailing edge of the sheet enters the processing tray. To be controlled.

  31 is a paper discharge rotating body, and one end thereof is pressed against the paper discharge roller 26 and rotates counterclockwise in FIG. 2 so as to transfer the sheet on the processing tray to the regulating stopper 30 side. The illustrated sheet discharge rotator 31 is formed of an endless belt, and is pivotally supported so that the front pulley side hangs down on the processing tray 29 around the pulley shaft 26z of the sheet discharge roller 26b.

  In the sheet discharge path P1 configured as described above, the sheet from the sheet discharge outlet 24 enters the processing tray 29 and is conveyed toward the stack tray 21 by the forward / reverse rotation roller 35, and the rear end of the sheet from the sheet discharge outlet 24. After entering the processing tray 29, when the forward / reverse rotation roller 35 is reversely rotated (counterclockwise in the figure), the sheet on the processing tray is transferred in the direction opposite to the paper discharge direction. At this time, the sheet discharge rotator 31 conveys the rear end of the sheet along the processing tray 29 toward the restriction stopper 30 in cooperation with the forward / reverse roller 35.

  A restriction stopper 30 and a stapling device 33 for restricting the position of the rear end of the sheet are disposed at the rear end of the processing tray 29 in the paper discharge direction. The illustrated stapling device 33 staples one or more rear end edges of the sheet bundle stacked on the processing tray. Further, the processing tray 29 is provided with a carry-out mechanism for carrying out the bound sheet bundle to the stack tray 21.

  The illustrated carry-out mechanism includes a grip claw 34a that grips a sheet bundle, a drive arm 34b that reciprocates the grip claw 34a left and right along the processing tray 29, and a paper discharge motor ME that operates the drive arm 34b. ing. The processing tray 29 is provided with alignment members 37a and 37b for aligning the width direction of the sheets stacked on the tray, and the configuration of the alignment members 37a and 37b is as described above.

  The first switchback conveyance path SP1 configured as described above aligns the sheets from the sheet discharge outlet 24 on the processing tray 29 in the “steple binding mode”, and this sheet bundle is end-face binding stapler device 33. Then, one or a plurality of the rear end edges are stapled. In the “print-out mode”, the sheet from the sheet discharge outlet 24 is conveyed toward the stack tray 21 along the processing tray 29 without being switched back. As shown in the figure, the sheet to be stapled is bridge-supported by the processing tray 29 and the stack tray 21 disposed downstream thereof. As a result, the apparatus can be made compact.

[Configuration of second switchback transport path]
The second switchback transport path SP2 branched from the paper discharge path P1 is provided with a stacking guide 40 as shown in FIG. 1, and the sheets from the paper discharge path P1 are aligned and stacked on this guide to form a pair of folding sheets. Fold with roller 41. The stacking guide 40 is provided with a saddle stitching stapler device 42 for binding the center of the sheet bundle before folding. The sheet bundle folded by the folding roller 41 is stored in the booklet storage tray 22.

[Description of control configuration]
The control configuration of the above-described image forming system will be described with reference to the block diagram of FIG. The image forming system shown in FIG. 1 includes a control unit (hereinafter referred to as “main body control unit”) 45 of the image forming apparatus A and a control unit (hereinafter referred to as “post-processing control unit”) 50 of the post-processing apparatus B. The main body control unit 45 includes a print control unit 46, a paper feed control unit 47, and an input unit (control panel) 16.

  Then, an “image forming mode” and a “post-processing mode” are set from the input unit (control panel) 16. The image forming mode sets mode settings such as color / monochrome printing, duplex / single-sided printing, and image forming conditions such as sheet size, sheet paper quality, number of printouts, and enlarged / reduced printing. The “post-processing mode” is set to, for example, “print-out mode”, “steple finishing mode”, “binding binding finishing mode”, or the like.

  The main body control unit 45 also sends a post-processing finishing mode and the number of sheets, information on the number of copies and binding mode (one-position binding or two or more bindings) information, and the sheet thickness of the sheet to be image-formed. Data transfer such as information. At the same time, the main body control unit 45 transfers a job end signal to the post-processing control unit 50 every time image formation is completed.

  The post-processing mode will be described. In the “print-out mode”, the sheet from the paper discharge port 24 is stored in the stack tray 21 without performing post-processing. In this case, the sheets are carried out from the discharge outlet 24 to the stack tray 21 without being aligned and stacked on the processing tray 29. In the “steple finishing mode”, the sheets from the sheet discharge outlet 24 are stacked on the processing tray 29 and aligned, and the sheet bundle is bound by the stapler device 33 and then stored in the stack tray 21. In this case, the sheet to be imaged is in principle designated by the operator to a sheet of the same paper thickness and the same size.

  In the “bookbinding binding finishing mode”, sheets formed by the image forming apparatus A are aligned and accumulated on the processing tray 29, and finally, the cover sheet is image-formed by the image forming apparatus A and superimposed on the sheets on the processing tray. After aligning and stapling, the stack tray 21 is accommodated. In this case, the cover sheet is designated by the operator as a cardboard sheet prepared in the sheet feeding unit 2.

[Post-processing control unit]
The post-processing control unit 50 is configured by a control CPU (control means; the same applies hereinafter) that operates the post-processing apparatus B in accordance with a designated post-processing mode. The post-processing control unit 50 includes a ROM 51 that stores an operation program and a RAM 52 that stores control data.

[Control of paper output rotating body]
The rotation of the sheet discharge rotator (forward / reverse roller) 35 is stopped at the timing when the sheet is moved downward from the retracted position Tp to the operating position Fp and when the position of the rotator reaches the restriction stopper 30 and the position is restricted. As described above, according to the present invention, the operation timing at which the forward / reverse rotation roller 35 is moved from the retracted position Tp to the operation position Fp and / or the operation stop timing when the sheet leading edge reaches the regulation stopper 30 by the paper discharge rotating body 35 is determined. It is characterized by being controlled by the sheet edge detection means Se arranged above.

  Hereinafter, the case where the operation stop timing is controlled by the sheet end detection means Se arranged on the processing tray 29 will be described. For this reason, a paper discharge sensor S2 for detecting the leading and trailing edges of the sheet is disposed at the paper discharge port 24. In this case, the control means (control CPU) 50 controls the shift motor MS and the forward / reverse motor M1 as described below based on the operation program stored in the ROM 51 and the control data stored in the RAM 52.

  The operation program determines whether or not the bracket 35a is positioned at the retracted position Tp based on a signal from a position sensor (not shown) at the time of initialization (initialization) when the apparatus is activated. When the sensor signal is OFF, the shift motor MS is activated in the upward direction to position the bracket 35a at the retracted position Tp. At the same time, this operation program is configured to detect when the leading edge of the sheet reaches the carry-in entrance 23 by the entrance sensor S1 and to rotationally drive the paper discharge roller (carry-out means) 26.

  At the same time, the paper discharge sensor S2 detects the trailing edge of the sheet, starts a timer, and starts the shift motor MS in the upward and downward direction by the timer time-up signal to swing the bracket 35a and rotate the paper discharge. The body (forward / reverse roller) 35 is lowered from the retracted position Tp to the operating position Fp. The forward / reverse rotation motor M1 rotates in the clockwise direction in FIG. 2 before the sheet discharge rotator (forward / reverse rotation roller) 35 reaches the operating position Fp.

  As a result, the sheet conveyed from the sheet discharge port 24 toward the processing tray 29 is guided at the leading end between the forward / reverse roller 35 and the uppermost sheet stacked on the processing tray. Then, the sheet is conveyed to the left side in FIG. 2 by the rotation of the forward / reverse roller 35 in the paper discharge direction (clockwise in FIG. 2). Therefore, the control means (control CPU) 50 detects the trailing edge of the sheet by the paper discharge sensor S1, and stops the forward / reverse roller 35 at the expected time when the trailing edge is carried out onto the paper discharge tray.

  The control means (control CPU) 50 reverses the forward / reverse motor M1 in the direction opposite to the paper discharge. Then, the sheet sent onto the processing tray is transferred to the restriction stopper 30 along the uppermost paper on the tray. Prior to the switchback conveyance of the sheet, the control means (control CPU) 50 positions the alignment means 37 described above at the detection position Dp (between the standby position Wp and the alignment position Ap). Therefore, the edge of the sheet leading edge toward the restriction stopper 30 is detected by the sheet edge detecting means Se in the aforementioned offset region Of.

  Therefore, the control means (control CPU) 50 operates a timer in response to the sheet leading edge detection signal from the sheet edge detecting means Se, and stops the forward / reverse rotation roller 35 after the time when the sheet leading edge reaches the restriction stopper 30. Since the sheet transported to the restriction stopper 30 by such control controls the roller conveyance amount based on the signal detected at the leading edge immediately before the restriction position, it may cause problems such as overrun, unreachable and skew of the sheet. Few. Next, the control means (control CPU) 50 causes the forward / reverse roller 35 to stand up from the operating position Fp to the retracted position Tp, and then controls the movement of the alignment means 37 from the standby position Wp to the alignment position Ap.

A Image forming apparatus B Post-processing apparatus C Sheet stacking apparatus 16 Control panel 21 Stack tray 22 Booklet storage tray 23 Loading port
24 Discharge port 26 Unloading means (conveyance roller) (discharge roller)
29 Processing tray (tray means)
30 Sheet edge regulating means (regulating stopper)
31 Paper discharge rotating body (scraping belt)
32 Post-processing unit 33 Stepper device 34a Grip claw 34b Drive arm 35 Paper discharge rotator (forward / reverse roller)
35a Bracket 37 Alignment means 37a Left alignment member 37b Right alignment member 40 Accumulation guide 45 Main body control unit 46 Print control unit 47 Paper feed control unit 50 Post-processing control unit (control CPU)
51 ROM
52 RAM
P1 paper discharge path
Fp operation position Tp retraction position Sk alignment reference position Fk discharge reference position Wp standby position Ap alignment position Dp detection position Se sheet edge detection means S1 entrance sensor S2 discharge sensor Ma, Mb alignment motor M1 forward / reverse motor Off offset region

Claims (7)

A paper discharge path having a discharging means for discharging the sheet from the paper discharge port;
Tray means for stacking sheets disposed on the downstream side of the paper discharge port;
Sheet end regulating means for regulating the edge of the sheet carried to the tray means;
A paper discharge rotator for transferring the sheet carried on the tray means toward the sheet end regulating means;
Elevating and lowering support means for supporting the discharge rotating body so as to be movable up and down between an operating position in contact with the sheet on the tray means and a retracted position separated from the sheet;
Aligning means for aligning the side edges of the sheets stored on the tray means in the sheet discharge orthogonal direction to a reference position;
Elevating and lowering driving means for elevating and lowering the paper discharge rotating body between an operating position and a retracted position;
Alignment driving means for operating the alignment means;
Sheet edge detecting means for detecting an edge of the sheet from the sheet discharge port;
Control means for controlling the lifting drive means based on a detection signal of the sheet edge detection means;
With
The discharge reference position of the unloading means and the alignment reference position of the alignment means are
A sheet side edge has been carried on said tray means, said as a sheet side edge that is aligned with alignment means, the offset region Ru at different predetermined amount located in the paper discharge direction perpendicular between the formed Set,
(1) The alignment means is composed of a pair of side edge guide members that align the sheets on the tray means to the alignment reference position.
The pair of side edge guide members form the offset region by displacing a sheet carried out from the paper discharge port by the carry-out means by a predetermined amount in a paper discharge orthogonal direction,
(2) The offset region is formed by providing the carry-out means with a jog mechanism for displacing a sheet in the sheet discharge path by a predetermined amount in the sheet discharge orthogonal direction,
(3) The unloading means and the alignment means are
A posture angle of the sheet unloaded from the sheet discharge port by the unloading means;
Forming the offset region by crossing the posture angle of the sheets that are aligned by the alignment means,
The sheet stacking apparatus according to claim 1, wherein the sheet end detecting unit is disposed at a position in the offset area on the tray unit to detect an edge of the sheet from the sheet discharge port to the sheet end regulating unit. The sheet edge detecting means is
Sheet stacking apparatus according to claim 1, characterized in that it is constituted by a sensor that is placed in accordance with the width size of the sheet carried out of the discharge outlet into the offset area on the tray means. The alignment means includes at least one movable alignment member that moves in a direction perpendicular to the paper discharge direction,
2. The sheet accumulating apparatus according to claim 1, wherein the sheet end detection unit is configured by a sensor that moves in a direction perpendicular to the sheet discharge by the movable alignment member. The sheet discharge rotating body is configured to switch back a sheet carried out from the sheet discharge port and transfer the sheet to the sheet end regulating means,
The sheet end detecting means, to any one of claims 1 to 3, characterized in that it is positioned to detect the sheet front end to move toward the sheet edge regulating means in the sheet discharge rotary body The sheet stacking apparatus described. The discharge reference position of the carry-out means that forms the offset area and the alignment reference position of the alignment means are configured so that the offset amount differs according to the speed of the sheet carried out from the discharge outlet. The sheet stacking apparatus according to claim 1. A post-processing device that performs post-processing by collecting and stacking image-formed sheets on a tray unit from a paper discharge path,
6. The post-processing apparatus according to claim 1, wherein the paper discharge path and the tray unit have the configuration according to any one of claims 1 to 5 . An image forming apparatus for forming an image on a sheet;
A post-processing device that performs post-processing by collecting and stacking sheets of images formed by the image forming apparatus; and
Consisting of
An image forming system having the configuration according to claim 6 .

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