JP2017121993A - Post-processing device and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous detection due to that a peak of a loading sheet bundle passes a detection point.SOLUTION: A post-processing device capable of processing sheet bending includes: transportation means for transporting a sheet subjected to bending processing; a sheet output tray for loading sheets output from the transportation means thereon; and detection means for detecting a plurality of height positions along a sheet output direction of an uppermost surface of the loaded sheet on the sheet output tray.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a copying machine, a printer, a facsimile machine, a post-processing apparatus mounted on an image forming apparatus such as a multi-function machine having these functions in combination, and image formation formed by connecting the post-processing apparatus to the image processing apparatus. About the system.

  In this type of post-processing apparatus and image forming system, there is an image forming system in which a post-processing apparatus having a processing function such as a staple binding process or a folding process is recently connected to a sheet on which an image is formed by the image forming apparatus. Proposed.

  The folding process performed by the post-processing device used in such an image forming system includes various folding processes such as bi-folding and Z-folding, and the folded sheets are sequentially stacked on the discharge tray. In many cases, the paper discharge tray is movable in the vertical direction, and the paper discharge tray is lowered when the number of stacked sheets increases.

  However, the sheet that has been subjected to the folding process is bulkier when stacked by the amount of the folded portion than the sheet that has not been subjected to the folding process.

  Therefore, as shown in FIG. 5, when the sheets W folded by using one sensor 100 are stacked, the uppermost surface of the folded portion W1, that is, the top of the stacked sheets W is detected. There has been proposed a post-processing device that lowers the discharge tray 101 when the stacked paper W reaches a predetermined height (Patent Document 1).

JP 2013-82537 A

  However, since the paper is stacked in an inclined state due to the folding part, the top of the loaded paper is detected by the detection sensor when the loaded paper loses balance and collapses or the paper size changes. May fall off. For this reason, in the case of a device that detects the top of the stacked paper using one sensor, a detection failure of the top of the stacked paper occurs and the paper discharge path to the paper discharge tray is not secured. There are problems such as paper discharge failure.

  An object of the present invention is to provide a post-processing apparatus and an image forming system which have been improved by examining the above-described present situation.

  The invention according to claim 1 is a post-processing apparatus capable of folding a sheet, a conveying unit that conveys the folded sheet, and a discharge tray that stacks the sheet discharged from the conveying unit And detecting means for detecting height positions at a plurality of locations along the paper discharge direction on the uppermost surface of the stacked paper on the paper discharge tray.

  According to a second aspect of the present invention, in the post-processing apparatus according to the first aspect, the detection means is composed of a plurality of sensors located above the paper discharge tray and arranged along the paper discharge direction. It is that.

  According to a third aspect of the present invention, in the post-processing apparatus according to the first or second aspect, the detection portion of the detection means is the apex of the stacked paper when the paper is stacked up to the upper limit of stacking or a position near the apex. That's it.

  According to a fourth aspect of the present invention, in the post-processing apparatus according to any one of the first to third aspects, the lifting / lowering means for raising and lowering the discharge tray and the lowering of the discharge tray based on the detection result of the detection means A sheet discharge tray control means for moving the sheet by a predetermined amount in the direction is provided.

  According to a fifth aspect of the present invention, in the post-processing apparatus according to the fourth aspect, the detecting means always detects the plurality of positions on the uppermost surface of the stacked sheets, and any one of the plurality of positions is a predetermined stacking position. When the height is detected, the paper discharge tray is moved downward.

  According to a sixth aspect of the present invention, in the post-processing apparatus according to the second or third aspect, the sensor is selectively used according to the paper size or the number of discharged sheets.

  A seventh aspect of the invention relates to an image forming system, wherein the post-processing device according to any one of the first to sixth aspects is provided.

  According to the present invention, a plurality of sensors arranged along the paper discharge direction can detect the top surface of the stacked paper in a wide range and accurately detect the apex of the stack of stacked paper. It is possible to prevent a detection failure at the top of the stacked paper when the stacked paper bundle collapses and the apex is misaligned. Further, it is possible to detect in a wide range according to the paper size and the number of discharged sheets.

1 is a diagram schematically illustrating an image forming system according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration of a control unit of the image forming system according to the embodiment of the present invention. It is a figure which shows the post-processing apparatus which concerns on embodiment of this invention. It is a flowchart which shows the operation example of a post-processing apparatus. It is a figure which shows the conventional post-processing apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(1) Outline of Image Forming System First, the apparatus configuration of image forming system 1 according to the embodiment of the present invention will be described. The image forming system 1 mainly includes an image forming apparatus 3 and a post-processing apparatus 2 attached to the image forming apparatus 3. Hereinafter, the post-processing apparatus 2 and the image forming apparatus 3 will be described with reference to FIGS. 1 and 2.

  The image forming apparatus 3 is an apparatus such as a copying machine, a printer, or a multifunction machine, and forms an image on the paper W. More specifically, the image forming apparatus 3 includes an automatic document feeder (ADF) that performs automatic continuous conveyance of a document in a copy operation and a scan operation, a scanner that reads the document and generates image data, and the like. A print engine for forming an image on a sheet (recording material) W based on image data generated by the scanner or image data stored in advance, and a sheet feeding unit for feeding the sheet W on which an image is formed by the print engine including. In addition, the image forming apparatus can transmit and receive data via a network (communication network) such as a LAN or a telephone line. The image forming apparatus inputs image data from another computer via the network and prints based on the image data. Can also be executed.

  As shown in FIG. 2, the image forming apparatus 3 includes a CPU 30, a communication unit 31, an image forming unit 32, a paper feed unit 33, a paper transport unit 34, and the like. The communication unit 31 transmits to the post-processing apparatus 2 paper information necessary for post-processing such as print job number information, paper size, paper media type (for example, basis weight of the paper W), post-processing settings, and the like. Necessary information such as the post-processing status is received from the post-processing device 2. The CPU 30 functions as a controller that controls image formation, paper feeding, paper conveyance, and the like according to information acquired from each unit. The image forming unit 32 performs an image forming operation in response to a command from the CPU 30. The paper feed unit 33 feeds a predetermined paper W to the image forming unit 32 according to a command from the CPU 30, and the paper transport unit 34 post-processes the paper W image-formed by the image forming unit 32. It is sent to the device.

  The post-processing apparatus 2 is attached to the image forming apparatus 3 and performs post-processing such as Z-folding on the paper W on which the image is formed in the image forming apparatus 3.

  The post-processing device 2 includes a CPU 20, a communication unit 21, a post-processing unit 22, a paper transport unit 23, a paper discharge unit 24, a tray height adjustment unit 24A, and the like. The communication unit 21 transmits necessary information such as the post-processing status to the communication unit 31 of the image forming apparatus 3 and receives the above-described paper information from the communication unit 31. The CPU 20 functions as a controller that performs control at the time of post-processing based on the paper information received by the communication unit 21, and the post-processing unit 22 performs predetermined post-processing in response to a command from the CPU 20. Is. The paper transport unit 23 transports the paper sent from the image forming apparatus 3, and the paper discharge unit 24 discharges the post-processed paper bundle.

(2) Tray height adjustment unit of post-processing apparatus (a) Configuration of tray height adjustment unit of post-processing apparatus As shown in FIG. 3, the tray height adjustment unit 24 </ b> A conveys a sheet that has been subjected to folding processing. Conveying means 24B, a paper discharge tray 24C for stacking the paper W discharged from the conveying means 24B, an upper paper discharge tray 24D positioned opposite to the stacking surface of the paper discharge tray 24C, and a back surface of the upper paper discharge tray 24D The four sensors S1 to S4 arranged in the upper and lower sections, lifting means (not shown) for raising and lowering the discharge tray 24C, and the discharge tray 24C is moved downward by a predetermined amount based on the detection results of the sensors S1 to S4. A discharge tray control means (not shown).

  Sensors S1 to S4 are distance measuring sensors that measure the distance to the upper surface of the stacked paper W, and are predetermined along the paper discharge direction in the uppermost surface of the stacked paper W on the paper discharge tray 24C. The height positions of the four positions located at intervals are detected.

  Then, as shown in FIG. 3, the distances to the folded portion (Z-folded portion) W1, which is the top of the stacked paper W, are measured using the sensors S1 to S4, and the shortest distance among them is measured. When H1 falls below a preset paper stacking upper limit position H, the paper discharge tray control means determines that the paper is overloaded and lowers the paper discharge tray 24C to prevent paper discharge failure.

  The sensors S1 to S4 are located at the apex position or a position near the apex position when 50 sheets of the specified upper limit stack number of Z-foldable sheets A3, B4, and WLT are stacked, and the apex positions of the detection ranges are A3, B4, and WLT. It is installed so as to cover the vicinity, and even when the stacking shape is changed due to variations in the paper type or stacking, it is possible to detect the apex of the stacking sheet with high accuracy or its vicinity, The vertex or its vicinity can be detected without being removed, and detection omission can be prevented. The sensors S1 to S4 always detect the top surface of the stacked paper W.

(B) Example of Operation of Tray Height Adjustment Unit of Post-Processing Device FIG. 4 is a flowchart showing an example of operation of the post-processing device.

  First, in S101, the paper W is discharged and stacked on the paper discharge tray 24C. In S102, it is determined whether or not the shortest distance H1 among the distances measured by the sensors S1 to S4 is less than the sheet stacking upper limit position H.

  If the shortest distance H1 is less than the paper stacking upper limit position H (YES in S102), the process proceeds to S103 to start lowering the discharge tray 24C. If not (NO in S102), the process of S102 is performed. repeat.

  As the paper discharge tray 24C is lowered, it is determined in S104 whether the shortest distance H1 is the same as or exceeds the paper stacking upper limit position H. If it exceeds (YES in S104), the process proceeds to S105 and the lowering of the discharge tray is stopped. If not (NO in S104), the process of S104 is repeated.

  As described above, when the upper surface of the stacked paper W is detected by the sensors S1 to S4, the position of the paper discharge tray 24C is adjusted by the paper discharge tray control unit that moves the paper discharge tray 24C downward. As a result, when a predetermined number of sheets of paper W are stacked, the discharge tray 24C is lowered to secure a sufficient conveyance path, and discharge defects due to buckling of discharged sheets can be prevented.

  The sensors S1 to S4 may be selectively used for ON / 0FF of each sensor used in accordance with the size and the number of sheets W to be discharged, even in a state in which all sensors are always detected. For example, when loading a WLT that is the maximum size of Z-foldable paper, the sensor S1 near the top of the WLT stacking position is turned on, and the sensor S4 close to the discharge port through which the paper is discharged toward the paper discharge tray is turned off. It doesn't matter how you use it. As a result, energy consumption can be suppressed.

  The sensors S1 to S4 are not limited to detecting only points, and may be area sensors that cover a necessary detection range.

  Note that the paper discharge may be stopped when the upper surface of the stacked paper is detected by the sensors S1 to S4.

(3) Modifications The present invention is not limited to the above-described embodiment, and can be embodied in various forms. The configuration of each part is not limited to the illustrated embodiment, and does not depart from the spirit of the present invention. Various changes are possible.

24C Paper discharge tray S1 to S4 Sensor W Paper

Claims (7)

A post-processing device capable of folding a sheet, a transport unit configured to transport the folded sheet, a paper discharge tray for stacking the paper discharged from the transport unit, and the paper discharge tray A detecting means for detecting a plurality of height positions along the paper discharge direction on the uppermost surface of the upper stacked paper;
Post-processing device. The detection means is composed of a plurality of sensors located above the paper discharge tray and arranged along the paper discharge direction.
The post-processing apparatus according to claim 1. The detection part of the detection means is the apex of the stacked paper when the paper is stacked up to the upper limit of stacking or a position near the apex,
The post-processing apparatus according to claim 1 or 2. Elevating means for raising and lowering the paper discharge tray, and paper discharge tray control means for moving the paper discharge tray downward by a predetermined amount based on the detection result of the detection means,
The post-processing apparatus in any one of Claims 1-3. The detecting means always detects the plurality of places on the uppermost surface of the stacked paper, and moves the discharge tray downward when detecting any of the plurality of places having a predetermined stacking height. Let
The post-processing apparatus according to claim 4. Use the sensor according to the paper size or the number of ejected sheets.
The post-processing apparatus according to claim 2 or 3. The post-processing apparatus according to claim 1 is provided.
Image forming system.

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