JP7537150B2 - Post-processing system and image forming system - Google Patents

Description

The present invention relates to a post-processing system and an image forming system.

Conventionally, in post-processing systems that fold paper on which an image has been formed, if misalignment occurs, the user or service technician visually determines the amount of misalignment in the output and performs an adjustment (changes the numerical value). However, there are cases where the optimal result cannot be obtained with a single adjustment operation, which is time-consuming, reduces productivity, and wastes resources.

For example, Patent Document 1 describes a technique for detecting misalignment in the Z-fold function.

JP 2014-141330 A

However, in the technology described in Patent Document 1, as shown in FIG. 15, if the timing at which multiple sensors (SE1, SE2) detect the folded paper is shifted, it is possible to detect skew misalignment. However, if the timing at which multiple sensors detect the paper is the same, such as in a pattern in which the folding position is skewed and the paper edge overlaps the paper surface as shown in FIG. 16, or in a pattern in which the folding position is shifted parallel to the transport direction and the paper edge overlaps the paper surface as shown in FIG. 17, it is not possible to detect fold misalignment.

The objective of the present invention is to accurately detect misalignment after folding, regardless of the state of misalignment.

In order to solve the above problems, the post-processing system of the present invention described in claim 1 comprises:
a folding unit that folds the paper;
an image reading unit that reads the paper after the folding process and obtains a read image;
A control unit that detects a folding misalignment based on the read image;
Equipped with
The image reading unit is capable of obtaining read images of both sides of the paper after the folding process,
The control unit detects a folding misalignment based on the scanned images of both sides of the sheet after the folding process.

The post-processing system of the present invention according to claim 2 comprises :
a folding unit that performs folding processing on the paper;
an image reading unit that reads the paper after the folding process and obtains a read image;
A control unit that detects a folding misalignment based on the read image;
Equipped with
The control unit detects straight line portions in the read image that are parallel to sides of a rectangular area predetermined according to the type of fold performed by the folding unit and the paper size of the paper, and have a length equal to or greater than a predetermined length according to the paper size of the paper, as paper edges that overlap the paper surface of the paper, and determines that a parallel fold misalignment has been detected when the number of paper edges overlapping the detected paper surface is greater than the number of paper edges on the paper surface under normal conditions that is predetermined for the type of fold performed by the folding unit.

The post-processing system of the present invention according to claim 3 comprises :
a folding unit that performs folding processing on the paper;
an image reading unit that reads the paper after the folding process and obtains a read image;
A control unit that detects a folding misalignment based on the read image;
Equipped with
The folding unit performs two folding processes on the sheet, and includes a first folding unit that performs a first folding process on the sheet and a second folding unit that performs a second folding process on the sheet,
the image reading unit includes a first image reading unit that reads the paper on which the first folding process has been performed to obtain a read image, and a second image reading unit that reads the paper on which the second folding process has been performed to obtain a read image,
When the control unit detects a folding misalignment in the first folding process based on the read image acquired by the first image reading unit, the control unit controls so as not to perform the second folding process .

The invention described in claim 4 is the invention described in any one of claims 1 to 3,
The control unit determines that a diagonal fold misalignment has been detected when a straight line portion is detected in the read image outside a rectangular area that is predetermined according to the type of fold performed by the folding unit and the paper size of the paper.

The invention described in claim 5 is the invention described in claim 2 or 4,
The types of folds include a center fold, an inner three fold, an outer three fold, a double parallel fold, a Z fold, or a gate fold.

The invention described in claim 6 is the invention described in any one of claims 1 to 5 ,
The folding position adjusting unit includes a selection unit for selecting whether or not to execute an automatic folding position adjustment function after detecting the folding misalignment.

The invention described in claim 7 is the invention described in any one of claims 1 to 6 ,
The control unit controls the sheet in which the misfolding has been detected to be discharged as waste paper.

The image forming system according to the eighth aspect of the present invention comprises :
an image forming apparatus for forming an image on a sheet;
Equipped with the aftertreatment system according to any one of claims 1 to 7,
The folding unit and the image reading unit are disposed downstream of the image forming device in the paper transport direction, and the folding unit applies a folding process to the paper on which the image is formed by the image forming device.

The present invention makes it possible to accurately detect misalignment after folding, regardless of the state of the misalignment.

1 is a diagram showing a schematic configuration of an image forming system according to a first embodiment. 1 is a block diagram showing a functional configuration of an image forming system according to a first embodiment. FIG. 13 is a diagram showing the number of paper edges on a paper surface under normal conditions for each type of folding. 13 is a flowchart showing the flow of a folding process control process A. FIG. 1A is a diagram showing an example of a read image obtained by reading a sheet of paper that has been normally Z-folded without any folding misalignment using the first reading unit, and FIG. 1B is a diagram showing a cross-section of a sheet of paper that has been normally Z-folded without any folding misalignment. 11 is a diagram showing an example of a read image acquired by reading, by a first reading unit, a sheet of paper on which skew has occurred when Z-folded; FIG. FIG. 1A is a diagram showing an example of a read image obtained by reading a sheet of paper that has been properly folded in third without any folding misalignment using the first reading unit, and FIG. 1B is a diagram showing a cross-section of a sheet of paper that has been properly folded in third without any folding misalignment. 11 is a diagram showing an example of a read image acquired by reading, by a first reading unit, a sheet of paper on which skew has occurred when folded outward in three; FIG. FIG. 1A is a diagram showing an example of a read image obtained by reading a sheet of paper in which parallel misalignment occurs when the sheet is folded in a Z-shape using a first reading unit, and FIG. 1B is a diagram showing a cross-section of a sheet of paper in which parallel misalignment occurs when the sheet is folded in a Z-shape. FIG. 1A is a diagram showing an example of a read image obtained by reading a sheet of paper in which parallel misalignment occurs when the sheet is folded in three on the outside, using the first reading unit; FIG. 1B is a diagram showing a cross-section of a sheet of paper in which parallel misalignment occurs when the sheet is folded in a Z-shape. FIG. 13 is a diagram showing a schematic configuration of an image forming system 200 according to a second embodiment. FIG. 11 is a block diagram showing a functional configuration of an image forming system 200 according to a second embodiment. 13 is a flowchart showing the flow of a folding process control process B. FIG. 13 is a schematic diagram showing how an outer three-fold is performed by folding the sheet twice, as viewed from above. FIG. 13 is a diagram for explaining detection of folding misalignment using a conventional technique. FIG. 13 is a diagram for explaining detection of folding misalignment using a conventional technique. FIG. 13 is a diagram for explaining detection of folding misalignment using a conventional technique.

The following describes in detail an embodiment of the present invention with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

First Embodiment
(Configuration of image forming system 100)
First, the configuration of the first embodiment will be described.
Fig. 1 is a diagram showing a schematic configuration of an image forming system 100 according to the present embodiment. Fig. 2 is a block diagram showing a functional configuration of the image forming system 100.
As shown in FIGS. 1 and 2, an image forming system 100 includes an image forming apparatus 1 and a post-processing system 2 .

The image forming device 1 forms an image on paper based on input image data. As shown in FIG. 2, the image forming device 1 is configured with a control unit 11, an operation display unit 12, a memory unit 13, a communication unit 14, an image forming unit 15, a paper feed unit 16, etc.

The control unit 11 includes a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). The CPU of the control unit 11 reads out a program stored in the ROM, loads the program into the RAM, and controls each part of the image forming apparatus 1 in accordance with the loaded program.
For example, when a print job (hereinafter, a job) including a folding process is input from an external device such as a PC (Personal Computer) via the communication unit 14, the control unit 11 executes a folding process control process A described later.

The operation display unit 12 is composed of an operation unit and a display unit. The operation unit has input devices such as operation keys and a touch panel arranged on top of the screen of the display unit, and converts input operations on these input devices into operation signals and outputs them to the control unit 11. The display unit has an LCD (Liquid Crystal Display) or the like, and displays an operation screen showing the status of the image forming device 1 and the post-processing system 2 and the contents of input operations on the touch panel.

The storage unit 13 is composed of a DRAM (Dynamic Random Access Memory), a HDD (Hard Disc Drive), etc., and stores image data of a job input from outside, job setting information, etc. Here, the job setting information includes image forming conditions such as the paper type and paper size used in the job, single-sided/double-sided printing, and information on post-processing to be performed in the job, such as the page on which folding processing is performed and the type of folding.
The memory unit 13 also stores, for each type of fold, the number of paper edges that overlap on the paper surface when folded normally (see Figure 3; the number of paper edges on the top and bottom sides of the paper). The memory unit 13 also stores information (size and position) of a predetermined rectangular area (area equivalent to the paper area after normal folding) for each combination of fold type and paper size. The memory unit 13 also stores the vertical and horizontal widths of the image formation area for each paper size. The memory unit 13 also stores various adjustment values.
Here, the edge of the paper refers to the end of the paper or a portion that has been folded to form the end of the paper (called a folded portion of the paper).

In this embodiment, as shown in FIG. 3, a case where the paper edge on the top surface of the paper is 1 during normal Z-folding is described as an example, but the paper edge on the bottom surface of the paper may also be 1.

The communication unit 14 is configured with a NIC (Network interface card) or a serial interface, and transmits and receives data between an external PC and each device of the post-processing system 2.

The image forming unit 15 forms an image on paper based on the image data of the job stored in the storage unit 13, according to the control of the control unit 11. As the image forming method of the image forming unit 15, various methods such as an electrophotographic method or an inkjet method can be adopted.

The paper feed unit 16 has a paper feed tray that stores paper, and feeds paper according to the control from the control unit 11.

The post-processing system 2 is configured with a folding device 3, an image reading device 4, and a paper discharge device 5. The post-processing system 2 may further include other post-processing devices.

The folding device 3 (folding section) performs folding processing on the paper conveyed from the image forming device 1. As shown in FIG. 2, the folding device 3 is configured with a control section 31, a communication section 32, a folding section 33, etc.

The control unit 31 includes a CPU, a ROM, and a RAM. The CPU of the control unit 31 reads out a program stored in the ROM, loads it into the RAM, and controls each part of the folding device 3 in accordance with the loaded program.
For example, when the control unit 31 receives information regarding the type of folding to be performed on each page of a job from the image forming device 1 via the communication unit 32, the control unit 31 performs a folding process on the paper transported from the image forming device 1 based on the received information, and transports the folded paper to the image reading device 4 by a transport roller or the like (not shown).

The communication unit 32 is configured with a NIC or a serial interface, etc., and transmits and receives data between the image forming device 1 and each device of the post-processing system 2.

The folding unit 33 folds the paper conveyed from the image forming device 1. In this embodiment, the folding unit 33 performs a center fold, an inner triple fold, an outer triple fold, a double parallel fold, a Z fold, or a gate fold on the conveyed paper, as shown in FIG. 3.

The image reading device 4 (image reading section) reads the folded paper conveyed from the folding device 3 and transmits the obtained read image to the image forming device 1. As shown in FIG. 2, the image reading device 4 is configured with a control section 41, a communication section 42, a first reading section 43, a second reading section 44, etc.

The control unit 41 includes a CPU, a ROM, and a RAM. The CPU of the control unit 41 reads out a program stored in the ROM, loads it into the RAM, and controls each part of the image reading device 4 in accordance with the loaded program.
For example, the control unit 41 causes the first reading unit 43 and the second reading unit 44 to read the folded paper transported from the folding device 3, transmits the obtained read image data to the image forming device 1 via the communication unit 42, and transports the read paper to the paper discharge device 5 using a transport roller or the like not shown.

The communication unit 42 is configured with a NIC or a serial interface, etc., and transmits and receives data between the image forming device 1 and each device of the post-processing system 2.

The first reading unit 43 reads the upper surface of the transported paper. The second reading unit 44 reads the lower surface of the transported paper. The first reading unit 43 and the second reading unit 44 are configured with a linear image sensor (e.g., a CCD line sensor), an optical system, a light source, etc., and read the paper transported from the folding device 3 and output the obtained read image to the control unit 41. Note that the readable range of the first reading unit 43 and the second reading unit 44 is larger than the paper size.

The paper discharge device 5 includes a control unit 51, a communication unit 52, a first tray 53, a second tray 54, and a transport roller (not shown). The paper discharge device 5 discharges the paper transported from the image reading device 4 to the first tray 53 or the second tray 54 under the control of the control unit 11.

(Operation of Image Forming System 100)
Next, the operation of the image forming system 100 will be described.
Fig. 4 is a flowchart showing the flow of a folding process control process A executed by the control unit 11 when image data and setting information of a job including folding process are received by the communication unit 14. The folding process control process A in Fig. 4 is executed by the CPU of the control unit 11 in cooperation with a program stored in the ROM.

First, the control unit 11 causes the paper feed unit 16 to transport paper and form an image on the paper based on the image data of the job (step S1).

Next, the control unit 11 causes the folding device 3 to execute a type of folding process designated by the job on the paper on which the image has been formed (step S2).
In the folding device 3, based on a control signal from the control unit 11 received via the communication unit 32, the control unit 31 causes the folding unit 33 to perform a specified type of folding process on the transported paper.

Next, the control unit 11 causes the image reading device 4 to read the folded paper and obtain a read image (step S3).
In the image reading device 4, based on a control signal from the control unit 11 received via the communication unit 42, the control unit 41 causes the first reading unit 43 and the second reading unit 44 to read the transported paper, and transmits the obtained read image data to the control unit 11 via the communication unit 42.

Next, the control unit 11 performs edge detection from the acquired scanned image (step S4).

Next, the control unit 11 determines, based on the detected edges, whether or not a straight line portion has been detected outside a predetermined rectangular area for the combination of the type of folding performed and the paper size (step S5).
The predetermined rectangular area is an area that corresponds to the area of the sheet after normal folding processing for each combination of the folding type and the sheet size, and is stored in the storage unit 13 .
If it is determined that a straight line portion has been detected outside a predetermined rectangular area (step S5; YES), the control unit 11 determines that a diagonal folding misalignment has been detected (step S6), and proceeds to step S10.

Figure 5(a) shows an example of a read image obtained by reading a sheet of paper that has been properly Z-folded without any misalignment using the first reading unit 43, and Figure 5(b) shows a cross-section of a sheet of paper that has been properly Z-folded without any misalignment. Dimensions are also shown in Figures 5(a) and (b). Also, the background and outer frame of the read image are omitted in Figures 5(a) and (b).

Fig. 6 is a diagram showing an example of a read image obtained by reading a sheet in which skew has occurred when the sheet is Z-folded by the first reading unit 43. In Fig. 6, the background and outer frame of the read image are omitted.
When Z-folding is performed, the solid-line rectangular area shown in Fig. 5(a) is the paper area, which coincides with the above-mentioned rectangular area, but straight line portions indicated by L1 and L2 are detected outside the above-mentioned rectangular area (i.e., the paper area) in the read image in Fig. 6. In this way, when straight line portions are detected outside the predetermined rectangular area in the read image by at least one of the first reading unit 43 or the second reading unit 44, the control unit 11 determines that a diagonal misalignment has been detected.

Figure 7(a) shows an example of a scanned image obtained by reading a sheet of paper that has been properly folded in three without any misalignment using the first scanning unit 43, and Figure 7(b) shows a cross section of a sheet of paper that has been properly folded in three without any misalignment. Dimensions are also shown in Figures 7(a) and (b). Also, the background and outer frame of the scanned image are omitted in Figures 7(a) and (b).

Fig. 8 is a diagram showing an example of a read image obtained by reading a sheet of paper on which a skew occurred when the sheet was folded in three on the outside, using the first reading unit 43. In Fig. 8, the background and outer frame of the read image are omitted.
When an outer three-fold process is performed, the solid-line rectangular area shown in Fig. 7(a) is the paper area, which coincides with the above-mentioned rectangular area, but in the read image in Fig. 8, straight line portions indicated by L3 to L5 are detected outside the above-mentioned rectangular area (i.e., the paper area). In this way, when straight line portions are detected outside the predetermined rectangular area in the image read by at least one of the first reading unit 43 or the second reading unit 44, the control unit 11 determines that a diagonal misalignment has been detected.
Similarly, for center folds, inner tri-folds, double parallel folds, and gate folds, if a straight line portion is detected outside a predetermined rectangular area in the image read by at least one of the first reading unit 43 or the second reading unit 44, the control unit 11 determines that a diagonal misalignment has been detected.

On the other hand, if it is determined that no straight line portion has been detected in the scanned image outside the rectangular area predefined for the combination of the type of fold and paper size performed (step S5; NO), the control unit 11 determines, based on the edges detected in step S4, whether or not a straight line portion that is parallel to a side of the rectangular area predefined for the combination of the type of fold and paper size and is longer than a predetermined length has been detected in the scanned image (step S7).

Here, in the scanned image, not only are the edges of the paper detected as straight lines, but the image formed on the paper may also contain straight lines. However, the area on the paper where an image can be formed is determined for each paper size, and a margin is provided around the area where an image can be formed, so a straight line that is parallel to the side of the area where an image can be formed (i.e., parallel to the side of the rectangular area described above) and longer than its width (a straight line longer than a specified length) can be determined to be the edge of the paper, rather than a straight line formed as an image.

If it is determined that a straight line portion that is parallel to a side of a predetermined rectangular area and is longer than a predetermined length has been detected (step S7; YES), the control unit 11 determines whether the number of straight line portions detected in step S7 is greater than the number of paper edges on the paper surface under normal conditions (see Figure 3), which is preset according to the type of fold (step S8).

If it is determined that the number of straight line portions detected in step S7 is greater than the number of paper edges on the paper surface under normal conditions, which is preset according to the type of fold (step S8; YES), the control unit 11 determines that a fold misalignment parallel to the edge of the paper (parallel misalignment) has been detected (step S9), and proceeds to step S10.

Fig. 9A is a diagram showing an example of a read image obtained by reading a sheet of paper on which parallel misalignment occurs when the sheet is folded in a Z-shape by the first reading unit 43. Fig. 9B is a diagram showing a cross section of the sheet of paper on which parallel misalignment occurs when the sheet is folded in a Z-shape. Note that dimensions are also shown in Figs. 9A and 9B. Also, the background and outer frame of the read image are omitted in Figs. 9A and 9B.
The read image and dimensions when there is no parallel misalignment are as shown in FIGS. 5(a) and 5(b), and in FIGS. 9(a) and 9(b), the leading edge of the paper is misaligned 1 cm toward the trailing edge of the paper.

As shown in FIG. 9A, in the image read by the first reading unit 43 of a sheet of paper on which parallel misalignment occurred during Z-folding, the number (2) of straight line portions that are parallel to the sides of the above-mentioned predetermined rectangular area (see FIG. 5A) and longer than a predetermined length (image formable area width) is greater than the number of paper edges on the surface of the sheet when Z-folding is performed normally (1, see FIG. 3). In this way, the control unit 11 determines that parallel misalignment has been detected when the number of straight line portions that are parallel to the sides of the predetermined rectangular area (see FIG. 5A) and longer than a predetermined length (image formable area width) is greater than the number of paper edges on the surface of the sheet when Z-folding is performed normally in the image read by at least one of the first reading unit 43 or the second reading unit 44.

Fig. 10(a) is a diagram showing an example of a read image obtained by reading a sheet of paper on which parallel misalignment occurs when the sheet is folded outward in three, using the first reading unit 43. Fig. 10(b) is a diagram showing a cross section of the sheet of paper on which parallel misalignment occurs when the sheet is folded outward in three. Note that dimensions are also shown in Figs. 10(a) and (b). Also, the background and outer frame of the read image are omitted in Figs. 10(a) and (b).
The read image and dimensions when there is no parallel misalignment are as shown in Figures 7(a) and (b). In Figure 10(a), the leading edge of the paper is misaligned 1 cm toward the rear end of the paper, and the folded portion of the paper is misaligned 1 cm toward the leading edge.

As shown in Fig. 10A, in the image read by the first reading unit 43 of a sheet of paper on which parallel misalignment has occurred when the sheet is folded outward in three, the number (2) of straight line portions that are parallel to the sides of the above-mentioned predetermined rectangular area (see Fig. 7A) and longer than a predetermined length (image formable area width) is greater than the number of paper edges on the surface of the sheet when the sheet is folded outward in three (0, see Fig. 3). Thus, the control unit 11 determines that parallel misalignment has been detected when the number of straight line portions that are parallel to the sides of the predetermined rectangular area (see Fig. 7A) and longer than a predetermined length (image formable area width) is greater than the number of paper edges on the surface of the sheet when the sheet is folded outward in three (
Similarly, for center folds, inner tri-folds, double parallel folds, and gate folds, if the number of straight line portions in the read image by at least one of the first reading unit 43 or the second reading unit 44 that are parallel to the sides of a predetermined rectangular area (see Figure 7 (a)) and longer than a specified length (width of the image formable area) is greater than the number of paper edges on the paper surface when the folding process is performed normally, the control unit 11 determines that parallel misalignment has been detected.

In step S10, the control unit 11 controls the paper discharge device 5 to discharge the paper in which the misalignment has been detected as waste paper onto the second tray 54 (step S10).
This makes it easy to distinguish waste paper on which misalignment has been detected from output (delivery product).

Next, the control unit 11 judges whether or not the execution of the automatic folding position adjustment function has been selected (step S11).
Here, the user can select through the operation display unit 12 whether or not to execute the automatic adjustment function for the folding position when a folding misalignment is detected.

When it is determined that the automatic folding position adjustment function has not been selected (step S11; NO), the control unit 11 proceeds to step S14.
When it is determined that the automatic folding position adjustment function has been selected (step S11; YES), the control unit 11 executes the automatic folding position adjustment function (step S12).
For example, when the control unit 11 determines that a diagonal misalignment has occurred, it measures the amount of protrusion due to the diagonal misalignment from a predetermined rectangular area based on the read image (the amount of protrusion in a direction perpendicular to the paper transport direction), and adjusts the amount of pressure applied to an alignment plate (not shown) provided in the folding device 3 for aligning the paper based on the measurement result.
Also, for example, when the control unit 11 determines that a parallel misalignment has occurred, it detects the position in the paper transport direction where each fold was performed based on the read image, and adjusts the position where each fold is performed based on the detection result of the position where each fold was performed.
This eliminates the need for the user to visually determine and adjust the amount of misalignment.

On the other hand, if it is determined in step S7 that no straight line portion that is parallel to the predetermined rectangular area and longer than the predetermined length has been detected (step S7; NO), or if it is determined in step S8 that the number of straight line portions detected in step S7 is equal to or less than the number of paper edges on the normal paper surface that is preset according to the type of fold (step S8; NO), the control unit 11 causes the paper discharge device 5 to discharge the folded paper as an output (product) onto the first tray 53 (step S13), and proceeds to step S14.

In step S14, the control section 11 determines whether or not the job is completed (step S14).
When it is determined that the job is not completed (step S14; NO), the control unit 11 returns to step S1.
When it is determined that the job is completed (step S14; YES), the control section 11 ends the folding process control process A.

Note that the processing of steps S2 to S10 and 13 is not limited to being performed for each sheet of paper, but may also be performed for multiple sheets of paper (i.e., for a stack of sheets of paper).

In this way, in the first embodiment, misalignment is detected based on the scanned image of the folded paper, so that misalignment can be accurately detected regardless of the state of the misalignment. In addition, by reading both sides of the folded paper after a folding process that includes multiple folds is performed, all misalignment that occurred during the multiple folds can be efficiently detected with a single reading operation. By detecting misalignment accurately and efficiently, productivity is improved without the hassle of users and service personnel, and waste of resources can be prevented.

Second Embodiment
A second embodiment of the present invention will now be described.

(Configuration of image forming system 200)
First, the configuration of the second embodiment will be described.
Fig. 11 is a diagram showing a schematic configuration of an image forming system 200 according to this embodiment, Fig. 12 is a block diagram showing a functional configuration of the image forming system 200.
As shown in FIGS. 11 and 12, an image forming system 200 includes an image forming apparatus 1 and a post-processing system 2A.

In the second embodiment, the storage unit 13 of the image forming device 1 stores predetermined rectangular areas (areas equivalent to the paper area after normal folding) for each fold type and paper size, corresponding to the first folding process and the second folding process. The rest of the configuration of the image forming device 1 is similar to that described in the first embodiment, so the description will be used to explain the configuration of the post-processing system 2A.

As shown in Figs. 11 and 12, the post-processing system 2A is configured to include a first folding device 3A (first folding section), a first image reading device 4A (first image reading section), a second folding device 3B (second folding section), a second image reading device 4B (second image reading section), and a paper discharge device 5. In the post-processing system 2A, the first folding device 3A performs the first folding process of the folding process that is completed in two steps (e.g., an outer three-fold, an inner three-fold, a Z-fold, etc.), and the paper after the first folding process is read by the first image reading device 4A. After that, the second folding device 3B performs a second folding process on the paper after the first folding process, and the paper after the second folding process is read by the second image reading device 4B.

The first folding device 3A is configured with a control unit 31A, a communication unit 32A, and a folding unit 33A, and each unit is connected via a bus.

The control unit 31A includes a CPU, a ROM, and a RAM. The CPU of the control unit 31A reads out a program stored in the ROM, loads it into the RAM, and controls each part of the first folding device 3A in accordance with the loaded program.
For example, when the control unit 31A receives information regarding the type of folding to be performed on each page of a job from the image forming device 1 via the communication unit 32A, based on the received information, it causes the folding unit 33A to perform a first folding process on the paper transported from the image forming device 1, and then causes the folded paper to be transported to the first image reading device 4A by a transport roller or the like (not shown).

The communication unit 32A is configured with a NIC or a serial interface, etc., and transmits and receives data between the image forming device 1 and each device of the post-processing system 2A.

The folding unit 33A folds the paper conveyed from the image forming device 1. In this embodiment, the folding unit 33A performs the first folding process on the conveyed paper for folding that is completed in two steps, such as an inner triple fold, an outer triple fold, or a Z fold.

The first image reading device 4A reads the paper that has been conveyed from the first folding device 3A and has undergone the first folding process, and transmits the obtained read image to the image forming device 1. As shown in FIG. 12, the first image reading device 4A is configured to include a control unit 41A, a communication unit 42A, a first reading unit 43A, and a second reading unit 44A.

The control unit 41A includes a CPU, a ROM, and a RAM. The CPU of the control unit 41A reads out a program stored in the ROM, loads it into the RAM, and controls each unit of the first image reading device 4A in accordance with the loaded program.
For example, the control unit 41A causes the first reading unit 43A and the second reading unit 44A to read the paper that has been folded for the first time and is transported from the first folding device 3A, transmits the obtained read image data to the image forming device 1 via the communication unit 42A, and transports the read paper to the second folding device 3B by a transport roller or the like (not shown).

The communication unit 42A is configured with a NIC or a serial interface, etc., and transmits and receives data between the image forming device 1 and each device of the post-processing system 2A.

The first reading unit 43A reads the upper surface of the transported paper. The second reading unit 44A reads the lower surface of the transported paper. The first reading unit 43A and the second reading unit 44A are configured with a linear image sensor (e.g., a CCD line sensor), an optical system, a light source, etc., and read the paper transported from the first folding device 3A and output the obtained read image to the control unit 41A. Note that the readable range of the first reading unit 43A and the second reading unit 44A is larger than the paper size.

The second folding device 3B is configured with a control unit 31B, a communication unit 32B, and a folding unit 33B, and each unit is connected via a bus.

The control unit 31B includes a CPU, a ROM, and a RAM. The CPU of the control unit 31B reads out a program stored in the ROM, loads it into the RAM, and controls each part of the second folding device 3B in accordance with the loaded program.
For example, when the control unit 31B receives information on the type of folding to be performed on each page of a job from the image forming device 1 via the communication unit 32B, based on the received information, it causes the folding unit 33B to perform a second folding process on the paper transported from the first image reading device 4A, and transports the folded paper to the second image reading device 4B by a transport roller or the like (not shown).

The communication unit 32B is configured with a NIC or a serial interface, etc., and transmits and receives data between the image forming device 1 and each device of the post-processing system 2A.

The folding unit 33B folds the paper conveyed from the first image reading device 4A. In this embodiment, the folding unit 33B performs a second folding process on the conveyed paper for folds that are completed by two folding processes, such as an inner triple fold, an outer triple fold, or a Z fold.

The second image reading device 4B reads the paper that has been folded for the second time and is conveyed from the second folding device 3B, and transmits the obtained read image to the image forming device 1. As shown in FIG. 2, the second image reading device 4B is configured with a control unit 41B, a communication unit 42B, a first reading unit 43B, a second reading unit 44B, etc.

The control unit 41B includes a CPU, a ROM, and a RAM. The CPU of the control unit 41B reads out a program stored in the ROM, loads it into the RAM, and controls each part of the second image reading device 4B in accordance with the loaded program.
For example, the control unit 41B causes the first reading unit 43B and the second reading unit 44B to read the paper that has been folded the second time and is transported from the second folding device 3B, and transmits the obtained read image data to the image forming device 1 via the communication unit 42B, and transports the read paper to the paper discharge device 5 by a transport roller or the like not shown.

The communication unit 42B is configured with a NIC or a serial interface, etc., and transmits and receives data between the image forming device 1 and each device of the post-processing system 2A.

The first reading unit 43B reads the upper surface of the transported paper. The second reading unit 44B reads the lower surface of the transported paper. The first reading unit 43B and the second reading unit 44B are configured with a linear image sensor (e.g., a CCD line sensor), an optical system, a light source, etc., and read the paper transported from the second folding device 3B and output the obtained read image to the control unit 41B. Note that the readable range of the first reading unit 43B and the second reading unit 44B is larger than the paper size.

The paper discharge device 5 is similar to that described in the first embodiment, so the description will be used here.

(Operation of Image Forming System 200)
Next, the operation of the image forming system 200 will be described.
Fig. 13 is a flowchart showing the flow of a folding process control process B executed by the control unit 11 when image data and setting information of a job including folding process are received by the communication unit 14. The folding process control process B in Fig. 13 is executed by the CPU of the control unit 11 in cooperation with a program stored in the ROM.

First, the control unit 11 causes the paper feed unit 16 to transport paper and form an image on the paper based on the image data of the job (step S21).

Next, the control section 11 causes the first folding device 3A to execute a first folding process of the type of folding specified by the job on the sheet on which the image has been formed (step S22).
In the first folding device 3A, based on a control signal from the control unit 11 received via the communication unit 32A, the control unit 31A causes the folding unit 33A to perform the first fold of the specified type of folding process on the transported paper.

Next, the control unit 11 causes the first image reading device 4A to read the paper that has been folded for the first time, and obtains a read image (step S23).
In the first image reading device 4A, based on a control signal from the control unit 11 received via the communication unit 42A, the control unit 41A causes the first reading unit 43A and the second reading unit 44A to read the transported paper, and transmits the obtained read image data to the control unit 11 via the communication unit 42A.

Next, the control unit 11 performs edge detection from the acquired scanned image (step S24).

Next, the control unit 11 determines whether or not a folding misalignment has been detected based on the detected edge (step S25).
In step S25, the control unit 11 judges whether or not a straight line portion is detected outside a predetermined rectangular area (here, an area corresponding to the paper area after the first normal folding process) for the combination of the type of folding performed, as described in step S5 of Fig. 4. If it is determined that a straight line portion is detected outside the predetermined rectangular area, the control unit 11 determines that a diagonal folding misalignment is detected.
When it is determined that no straight line portion is detected outside the predetermined rectangular area, for example, the control unit 11 determines whether or not a rectangular area of the same size as the predetermined rectangular area exists in the read image. When it is determined that a rectangular area of the same size as the predetermined rectangular area does not exist, the control unit 11 determines that a misalignment parallel to the leading edge of the paper has been detected. When it is determined that a rectangular area of the same size as the predetermined rectangular area exists, the control unit 11 determines that a misalignment has not been detected.

If it is determined that a fold misalignment has been detected (step S25; YES), the control unit 11 causes the second folding device 3B to convey the paper for which it has been determined that a fold misalignment has been detected toward the second image reading device 4B without performing a second folding process, and causes the second image reading device 4B to convey the paper toward the paper discharge device 5 without reading the paper (step S26), and proceeds to step S31.

On the other hand, if it is determined in step S25 that no fold misalignment has been detected (step S25; YES), the control unit 11 causes the second folding device 3B to perform a second folding process of the type specified in the job on the paper that has been folded the first time (step S27).
In the second folding device 3B, based on a control signal from the control unit 11 received via the communication unit 32B, the control unit 31B causes the folding unit 33B to perform a second folding process of the specified type on the transported paper.

Next, the control unit 11 causes the second image reading device 4B to read the paper that has been folded for the second time, and obtains a read image (step S28).
In the second image reading device 4B, based on a control signal from the control unit 11 received via the communication unit 42B, the control unit 41B causes the first reading unit 43B and the second reading unit 44B to read the transported paper, and transmits the obtained read image data to the control unit 11 via the communication unit 42B.

Next, the control unit 11 performs edge detection from the acquired scanned image (step S29).

Next, the control unit 11 determines whether or not a folding misalignment has been detected based on the detected edge (step S30).
In step S30, for example, the processes of steps S5 to S9 in FIG. 4 described in the first embodiment are executed, and if an oblique deviation or parallel deviation is detected, it is determined that a folding deviation has been detected.

If it is determined that a folding misalignment has been detected (step S30; YES), the control unit 11 proceeds to step S31.

In step S31, the control unit 11 controls the sheet ejection device 5 to eject the sheet in which the misalignment has been detected onto the second tray 54 as waste paper (step S31).
This makes it easy to distinguish waste paper on which misalignment has been detected from output (delivery product).

Next, the control unit 11 determines whether or not the execution of the automatic folding position adjustment function has been selected (step S32).
Here, the user can select through the operation display unit 12 whether or not to execute the automatic adjustment function for the folding position when a folding misalignment is detected.

When it is determined that the automatic folding position adjustment function has not been selected (step S32; NO), the control unit 11 proceeds to step S35.
When it is determined that the automatic folding position adjustment function has been selected (step S32; YES), the control unit 11 executes the automatic folding position adjustment function (step S33), and proceeds to step S35.
The process of step S33 is similar to the process of step S12, and therefore the explanation thereof will be cited.

On the other hand, if it is determined in step S30 that there is no misalignment (step S30; NO), the control unit 11 causes the paper that has been folded to be discharged as an output (product) to the first tray 53 by the paper discharge device 5 (step S34), and proceeds to step S35.

In step S35, the control section 11 determines whether or not the job is completed (step S35).
When it is determined that the job is not completed (step S35; NO), the control unit 11 returns to step S21.
When it is determined that the job is completed (step S35; YES), the control section 11 ends the folding process control process B.

Note that the processing of steps S22 to S31 and S34 is not limited to being performed for each single sheet of paper, but may also be performed for multiple sheets of paper (for a stack of sheets).

For example, when performing an outer triple fold, as shown in FIG. 14, the first fold is performed, and then the second fold is performed. However, in the second embodiment, if a fold misalignment is detected in the first fold, the second fold is not performed. This eliminates the need for an extra fold, and reduces wear and tear on the components (parts such as knives, motors, and rollers) used to perform the second fold.

In this way, in the second embodiment, misalignment is detected based on the scanned image of the folded paper, so that misalignment can be accurately detected regardless of the state of the misalignment. Furthermore, if a misalignment is detected in the first fold, a second fold is not performed, eliminating the need for an extra fold and reducing wear on the components (parts such as knives, motors, and rollers) used to perform the second fold.

The above describes the first and second embodiments of the present invention, but the description of the above embodiments is a preferred example of the post-processing system according to the present invention and is not limited to this.

For example, the image forming device 1 may be configured to include a scanner and form an image on paper based on image data read by the scanner.

In addition, for example, in the above embodiment, the control unit of the present invention that determines the folding misalignment based on the read images acquired by the first reading unit 43 and the second reading unit 44 (the first reading unit 43A and the second reading unit 44A, the first reading unit 43B and the second reading unit 44B) is the control unit 11 of the image forming device 1, but this is not limited to this. For example, the control unit 41 (41A) of the image reading device 4 (the first image reading device 4A) may realize the function as the control unit of the present invention. For example, the number of paper edges for each type of fold, information on the rectangular area predetermined for each combination of fold type and paper size, the length and width of the image forming area for each paper size, and the adjustment value of the folding position may be stored in a storage unit (not shown) of the image reading device 4 (first image reading device 4A), and when a job is started, the control unit 41 (41A) receives the job setting information from the image forming device 1 and performs steps S3 to S14 of the folding process control process A (steps S23 to S35 of the folding process control process B) on the folded paper based on the job setting information and the information stored in the storage unit. Also, the post-processing system 2 (2A) may be provided with a dedicated server or the like that realizes the functions of the control unit of the present invention.

In addition, in the above embodiment, an example was described in which the image forming device 1 and the post-processing system 2 are separate entities, but the post-processing system 2 may be provided within the image forming device 1.

In the above description, an example has been given in which a HDD or a semiconductor memory is used as a computer-readable medium for the program according to the present invention, but the present invention is not limited to this example.
As other computer-readable media, non-volatile memories such as flash memories, and portable recording media such as CD-ROMs can be used.
Furthermore, as a medium for providing data of the program according to the present invention via a communication line, a carrier wave is also applied to the present invention.

In addition, the detailed configuration and operation of the post-processing system may be modified as appropriate without departing from the spirit and scope of the present invention.

100, 200 Image forming system 1 Image forming device 11 Control unit 12 Operation display unit 13 Memory unit 14 Communication unit 15 Image forming unit 16 Paper feed unit 2 Post-processing system 3 Folding device 31 Control unit 32 Communication unit 33 Folding unit 4 Image reading device 41 Control unit 42 Communication unit 43 First reading unit 44 Second reading unit 5 Paper discharge device 51 Control unit 52 Communication unit 2A Post-processing system 3A First folding device 31A Control unit 32A Communication unit 33A Folding unit 4A First image reading device 41A Control unit 42A Communication unit 43A First reading unit 44A Second reading unit 3B Second folding device 31B Control unit 32B Communication unit 33B Folding unit 4B Second image reading device 41B control unit 42B communication unit 43B first reading unit 44B second reading unit

Claims (8)

a folding unit that folds the paper;
an image reading unit that reads the paper after the folding process and obtains a read image;
A control unit that detects a folding misalignment based on the read image;
Equipped with
The image reading unit is capable of obtaining read images of both sides of the paper after the folding process,
The control unit is a post-processing system that detects folding misalignment based on scanned images of both sides of the paper after the folding process . a folding unit that performs folding processing on the paper;
an image reading unit that reads the paper after the folding process and obtains a read image;
A control unit that detects a folding misalignment based on the read image;
Equipped with
The control unit detects straight line portions in the read image that are parallel to sides of a rectangular area predetermined according to the type of fold performed by the folding unit and the paper size of the paper, and have a length greater than or equal to a predetermined length according to the paper size of the paper, as paper edges that overlap the paper surface of the paper, and determines that a parallel fold misalignment has been detected when the number of paper edges overlapping the detected paper surface is greater than the number of paper edges on the paper surface under normal conditions that is predetermined for the type of fold performed by the folding unit. a folding unit that performs folding processing on the paper;
an image reading unit that reads the paper after the folding process and obtains a read image;
A control unit that detects a folding misalignment based on the read image;
Equipped with
The folding unit performs two folding processes on the sheet, and includes a first folding unit that performs a first folding process on the sheet and a second folding unit that performs a second folding process on the sheet,
the image reading unit includes a first image reading unit that reads the paper on which the first folding process has been performed to obtain a read image, and a second image reading unit that reads the paper on which the second folding process has been performed to obtain a read image,
The control unit controls the post-processing system so that the second folding process is not performed when it detects a folding misalignment with the first folding process based on the read image acquired by the first image reading unit . 4. The post-processing system according to claim 1, wherein the control unit determines that a diagonal fold misalignment has been detected when a straight line portion is detected in the scanned image outside a rectangular area that is predetermined according to the type of fold performed by the folding unit and the paper size of the paper. 5. The post-processing system according to claim 2 , wherein the type of folding is a center fold, an inner three fold, an outer three fold, a double parallel fold, a Z fold, or a gate fold. 6. The post-processing system according to claim 1, further comprising a selection unit for selecting whether or not to execute an automatic adjustment function for the folding position after detecting the folding misalignment. The post-processing system according to claim 1 , wherein the control unit controls the sheet in which the misalignment has been detected to be discharged as waste paper. an image forming apparatus for forming an image on a sheet;
The aftertreatment system according to any one of claims 1 to 7 is provided,
an image forming system, wherein the folding unit and the image reading unit are disposed downstream of the image forming device in a paper transport direction, and the folding unit applies a folding process to the paper on which the image is formed by the image forming device.

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