JP2011170281A - Image forming apparatus, paper feeder and image formation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize paper separation performance of a paper feeder, an image carrier and a fixing device, according to the grain direction of paper. <P>SOLUTION: A large-capacity paper feeder 300 includes: a grain direction detecting part 76 for detecting the grain direction of paper P at the top layer stored in a paper feed tray 74. The grain direction detecting part 76 is installed at a position inclined at a predetermined angle θ to a normal O in the grain direction detecting position T for the paper P, and parallel to the conveying direction D1 of the paper P in plan view. The grain direction detecting part 76 includes a light emitting part 77 and a light receiving part 78. The light emitting part 77 emits light to the grain direction detecting position T for the paper P according to an instruction of a control part. The light receiving part 78 receives the light emitted from the light emitting part 77 and reflected at the grain direction detecting position T for the paper P, and supplies detection voltage depending on the quantity of reflected light to a control part. The control part determines the grain direction of the paper P, based on the detected voltage, and reflects the result in the paper separation control in an image forming part or the fixing device or in the post processing control in a post processing device 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a digital multi-function machine having these functions using an electrophotographic method or an ink jet method, a paper feeding device, and an image forming system. More specifically, the paper separation performance and post-processing performance are improved by detecting the paper eye of the paper and reflecting the detection result in paper separation control and post-processing control.

  In recent years, an image forming apparatus such as a copying machine or a printer using an electrophotographic method or an ink jet method capable of forming a high-quality image has been widely used. The image forming apparatus includes an image carrier that carries a latent image, a developing device that develops the latent image on the image carrier, and heat-transfers the developed image onto a sheet of recording paper such as a transfer medium. And a fixing device for fixing.

  As a sheet used in the image forming apparatus, various sheets such as a sheet used in a normal office such as A4 size and B4 size, a glossy sheet for photography, and an inkjet sheet for inkjet are used. Since these papers have different characteristics such as paper quality and paper thickness, the image forming apparatus performs image forming processing under process conditions suitable for each paper. Process conditions include, for example, paper separation performance, paper transport speed, fixing roller pressure, fixing temperature, and the like. These process conditions are set for each paper to perform image forming processing.

  As a technique for detecting characteristics of paper, for example, surface roughness and smoothness, a method for detecting surface roughness or the like based on the amount of reflected light from an LED is known as a conventional technique. In Patent Document 1, light is irradiated to a detection area of a sheet by an LED, reflected light intensity reflected from the detection area is detected by an area sensor, frequency conversion such as two-dimensional FFT is performed, and the difference in frequency characteristics is detected. A color image recording apparatus for detecting the roughness of the surface is disclosed.

JP 2006-39025 A

  By the way, general paper used in the image forming apparatus has vertical or horizontal eyes due to the manufacturing process of the paper. This is because in the paper manufacturing process, paper fibers are aligned in the direction of scribing the paper, and the paper in which the fiber directions are aligned in a predetermined direction is cut into a predetermined size. In general, when the fiber direction is aligned in the longitudinal direction of the paper, it is called a vertical eye, and when the fiber direction is aligned in the short direction of the paper, it is called a horizontal eye. It is known that there is a difference in the expansion / contraction rate, bending rate, etc. of the paper between when the paper is vertical and when it is horizontal. Therefore, in order to execute optimal image formation processing, process conditions are considered that take into account not only the characteristics of paper roughness and smoothness, but also whether the paper grain is vertical or horizontal. There is a need to.

  However, in the image forming apparatus disclosed in Patent Document 1 and the conventional image forming apparatus, image forming processing is not performed in consideration of the grain of the paper, so that the paper separation performance of the paper feeding device, the photosensitive drum There is a problem that the transfer separation performance, the paper separation performance of the fixing device, and the paper folding performance, punch performance, and stapling performance of the post-processing device connected to the subsequent stage of the image forming apparatus are affected. That is, the expansion / contraction rate and bending rate of the paper differ depending on the paper direction of the paper, so if image forming processing that does not take into account the paper texture of the paper is not performed, paper separation performance, post-processing performance, etc. There is a problem of causing inconvenience.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to optimize the separation performance of the paper feeding device, the image carrier, and the fixing device according to the grain size of the paper. An object of the present invention is to provide an image forming apparatus, a sheet feeding device, and an image forming system.

  According to a first aspect of the present invention, there is provided an image forming apparatus for forming a predetermined image on a sheet in order to solve the above-described problem, a conveyance processing unit that conveys the sheet, and a first parallel to the sheet conveyance direction. Direction or a second direction orthogonal to the first direction, and irradiates the paper eye detection position with light from a position inclined by a predetermined angle with respect to the normal at the paper eye detection position of the paper. A paper eye detection unit that detects the amount of reflected light reflected at the eye detection position, and a paper eye that indicates the fiber direction of the paper based on the light amount of the reflected light detected by the paper eye detection unit, and the determination result And a control unit for controlling the paper separation performance in the conveyance processing unit.

  According to a ninth aspect of the present invention, there is provided a paper feeding device that accommodates paper and feeds the paper to the image forming apparatus, wherein the paper processing unit conveys the paper to the image forming apparatus, and is parallel to the paper conveyance direction. Provided in a first direction and / or a second direction orthogonal to the first direction, and light is emitted from a position inclined by a predetermined angle with respect to a normal line of the paper-sheet detection position of the paper to the paper-eye detection position. A paper detection unit that detects the amount of reflected light that is irradiated and reflected at the paper detection position by irradiation, and a paper pattern that indicates the fiber direction of the paper based on the amount of reflected light detected by the paper detection unit And a control unit that controls the paper separation performance in the conveyance processing unit based on the determination result.

  According to a tenth aspect of the present invention, there is provided an image forming system for forming a predetermined image on a sheet, a conveyance processing unit for conveying the sheet, and after performing a predetermined post-processing on the sheet conveyed by the conveyance processing unit. The processing unit is provided in a first direction parallel to the paper conveyance direction and / or in a second direction orthogonal to the first direction, and is inclined by a predetermined angle with respect to the normal line at the paper grain detection position of the paper Based on the amount of reflected light detected by the paper eye detection unit and the paper eye detection unit for detecting the amount of reflected light reflected at the paper eye detection position by irradiation. And a control unit that determines the sheet direction indicating the fiber direction of the sheet, and changes at least one of paper separation control in the conveyance processing unit and control in the post-processing unit based on the determination result.

  According to the first aspect of the invention, since the paper eye of the paper is detected by the paper eye detection unit and the detection result is reflected in the paper separation control, the paper separation performance can be optimized for each paper, and the paper separation performance can be further improved. Can be improved.

  According to the second aspect of the present invention, it is possible to detect the grain of the sheet having a curved portion. As a result, it becomes possible to detect the grain of the paper at various locations and to improve the degree of freedom in design.

  According to the third aspect of the invention, since the paper texture of the paper is determined based on the threshold value data and the detection data, the paper texture of the paper can be determined more accurately and quickly.

  According to the fourth aspect of the present invention, the paper texture is detected at two locations in the first direction and the second direction, so that the paper texture of the paper is more accurately compared to the case where the paper texture is detected at one location. Judgment can be made. Furthermore, since a threshold table or the like is not necessary, it is possible to reduce memory and work load for creating threshold data.

  According to the fifth aspect of the present invention, the paper movement detection in the two directions can be performed by the single movement detection unit by the moving mechanism, so that it can be performed with higher accuracy than the case where the paper detection is performed at one place. It is possible to determine the grain of the paper.

  According to the sixth aspect of the invention, the transfer separation control is changed for each sheet of paper, so that the paper separation performance can be further improved.

  According to the seventh aspect of the invention, since the fixing separation control is changed for each sheet of paper, the fixing separation performance can be further improved.

  According to the eighth aspect of the invention, since the paper grain information determined by the control unit of the image forming apparatus is supplied to the post-processing apparatus and the post-processing is controlled, the paper cutting process, the paper folding process, and the staple are performed. The performance of post-processing such as processing can be improved.

  According to the ninth aspect of the invention, the paper eye detection unit detects the paper eye of the paper, and the detection result is reflected in the paper separation control. Therefore, the paper separation performance can be optimized for each paper, and the paper separation performance can be further improved. Can be improved.

  According to the tenth aspect of the present invention, the paper detection unit detects the paper eye of the paper, and reflects the detection result in the paper separation control and the post-processing control, so that the paper separation performance and the post-processing performance can be improved. It can be optimized every time, and paper separation performance and post-processing performance can be further improved.

1 is a diagram illustrating a configuration example of an image forming system according to a first embodiment of the present invention. 1 is a diagram illustrating a block configuration example of an image forming system. It is a figure which shows the structural example of a determination table. (A) is a figure for demonstrating the function of the paper detection part when a paper is a horizontal eye, and (B) is a figure for demonstrating the function of a paper eye detection part when a paper is a horizontal eye. (A) is a perspective view showing a configuration example when the paper eye detection unit is installed in a large-capacity paper feeder, and (B) is a side view thereof. (A) is a perspective view showing a configuration example when a paper eye detection unit is installed in the vicinity of a photosensitive drum of an image forming apparatus, and (B) is a side view thereof. FIG. 6 illustrates an example of an operation of the image forming system (part 1). FIG. 10 illustrates an example of an operation of the image forming system (part 2). It is a figure which shows the block structural example of the image forming system which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structural example of a paper eye detection part. FIG. 10 illustrates an example of an operation of the image forming system (part 3). FIG. 10 illustrates an example of an operation of the image forming system (part 4).

Hereinafter, the best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described.
<1. First Embodiment>
[Configuration example of image forming system]
The image forming system GS according to the present invention detects the sheet P of the sheet P by the sheet detection units 50 and 76, and the detection result is detected after the sheet separation control of the image forming unit 20 and the fixing device 24 and the post-processing device 200. By reflecting it in the processing control, the paper separation performance and post-processing performance are improved. As shown in FIG. 1, the image forming system GS includes an image forming apparatus 100, a post-processing apparatus 200, and a large-capacity paper feeding apparatus 300.

  The image forming apparatus 100 includes an image forming apparatus main body 10, an automatic document feeder 18, an image reading unit 12, an image processing unit 14, an image writing unit 16, an image forming unit 20, a paper feeding unit 36, a fixing device 24, and a paper discharge unit. 38, an operation display unit 30, and a paper grain detection unit 50. The operation display unit 30 is a touch panel type input device, and is rotatably attached to the upper surface portion of the image forming apparatus main body 10 via a hinge portion. A menu screen (initial screen) or the like is displayed on the screen of the operation display unit 30, and predetermined image processing control is executed by selecting and pressing a predetermined item such as the menu screen.

  The image reading unit 12 scans and exposes the document d conveyed on the document table, reads the reflected light by the CCD image sensor, and photoelectrically converts the read reflected light into an analog image signal. The image processing unit 14 performs analog processing, A / D conversion processing, and shading correction processing on the analog image signal photoelectrically converted by the image reading unit 12, and outputs image data obtained by these processing to the image writing unit 16. . Based on the image data output from the image processing unit 14, the image writing unit 16 irradiates the surface of the photosensitive drum 28, which will be described later, with a laser beam from a laser diode (LD) to form an electrostatic latent image.

  The image forming unit 20 performs processing such as charging, exposure, development, transfer, separation, and cleaning based on the electrostatic latent image formed on the surface of the photosensitive drum 28 in order to form an image on a predetermined surface of the paper P. I do. In this example, the image forming unit 20 is described as being configured for black and white (monochrome), but of course, yellow (Y) color, magenta (M) color, cyan (C) color, and black (K) color. The image forming unit 20 having the color image forming function may be configured.

  The paper feed unit 36 is provided below the image forming unit 20 and includes a plurality of paper feed trays 36a, 36b, and 36c (hereinafter also referred to as a paper feed tray 36), a paper feed (feed-out) roller 37, and the like. Yes. A predetermined image is transferred to the paper P conveyed from the paper feed trays 36 a, 36 b, 36 c via the paper feed roller 37 and the like in the transfer unit 29 provided in the image forming unit 20, and the photosensitive drum is separated by the separation unit 27. It is separated from 28 and conveyed to the fixing device 24.

  The fixing device 24 fixes the toner image on the paper P by heating and pressure-bonding the paper P conveyed from the image forming unit 20 by the transfer conveyance roller. When the single-sided printing mode is set, the sheet P on which the fixing process has been performed is conveyed to the post-processing apparatus 200 at the subsequent stage via the paper discharge unit 38. On the other hand, when the duplex printing mode is set, the sheet is sent to the automatic duplex copy feeding unit 92 by the transport path switching plate 90 before being discharged or post-processed, and the single-sided image has been processed again by the image forming unit 20. An image is formed on the other side of the paper P. The paper P on which images are formed on both sides is again subjected to fixing processing by the fixing device 24 and is conveyed to the post-processing device 200, where it is discharged or subjected to predetermined post-processing.

  The large-capacity paper feeding device 300 is connected to the right side portion of the image forming apparatus main body 10 shown in FIG. 1, accommodates a large amount of paper P, and feeds the paper P one by one to the image forming apparatus main body 10. As described above, a predetermined image is transferred to the paper P conveyed from the large-capacity paper feeding device 300 in the transfer unit 29, and the toner image is fixed on the paper by the fixing device 24. To the post-processing apparatus 200.

  The post-processing device 200 is connected to the left side surface portion of the image forming apparatus main body 10 shown in FIG. 1 and performs stapling, folding, and punching processing on the paper P conveyed from the image forming apparatus main body 10. .

  The paper eye detection unit 50 detects the paper eye of the paper P by irradiating the paper P with light and detecting the amount of reflected light. For example, the paper eye detection unit 50 and the fixing device 24 of the image forming unit 20. It is installed near. The paper eye detection unit 76 is also installed in the large-capacity paper feeding device 300. The configuration and operation of the paper eye detection units 50 and 76 will be described later. In addition to the above-described photoconductor drum 28, the fixing device 24, and the large-capacity paper feeding device 300, the paper eye detection unit can be provided in the paper transport path and the post-processing device 200.

[Example of block configuration of image forming system]
Next, a block configuration example of the image forming system GS will be described. As shown in FIG. 2, the image forming system GS includes an image forming apparatus 100, a post-processing apparatus 200, and a large capacity sheet feeding apparatus 300. The image forming apparatus 100 includes a communication unit 44, an image reading unit 12, an image forming unit 20, a fixing device 24, an operation display unit 30, a paper grain detection unit 50, and a memory unit 42.

  The communication unit 44 has one end connected to the control unit 40 and the other end connected to the post-processing device 200 via the communication cable 11, and performs bidirectional communication with the post-processing device 200. For example, the paper pattern data Dp indicating the paper pattern of the paper P is transmitted from the control unit 40 of the image forming apparatus 100 to the post-processing apparatus 200 via the communication units 44 and 62 and the communication cable 11. The image reading unit 12 reads the document d based on the control signal supplied from the control unit 40, and outputs the image data of the read document d to the control unit 40.

  The operation display unit 30 includes an operation unit 32 and a display unit 34. In this example, a touch panel type input device in which the operation unit 32 and the display unit 34 are integrally formed is used, and an operation signal based on the position information pressed on the menu screen or the like of the display unit 34 is generated to generate a control unit. 40. On the menu screen or the like displayed on the display unit 34, the paper feed tray 36 is selected, or a mode for determining whether the paper of the paper P in the selected paper feed tray 36 is the same is selected. In addition, on the display screen of the display unit 34, paper grain information indicating whether the paper P determined by the control unit 40 is a vertical eye or a horizontal eye is displayed, and the user sets process conditions corresponding to the paper eye. It can be done.

  The memory unit 42 includes a non-volatile semiconductor memory, an HDD (Hard Disk Drive), and the like, and includes a determination table TB that is used when determining whether the paper P has vertical or horizontal eyes. Yes. As shown in FIG. 3, in the determination table TB, each paper type and threshold data Dth set for each paper type are stored in association with each other. For example, paper types include A4 size, A3 size, B5 size, glossy paper, inkjet paper, and the like, and different threshold data Dth1, Dth2, Dth3, Dth4, Dth5 are set corresponding to each paper type. Is done. For example, the threshold data Dth is obtained by measuring the detection voltage in the case of the vertical eye and the detection voltage in the case of the horizontal eye of each sheet before selling the product, and calculating a reference threshold value from these measured detection voltages. . Moreover, it is good also as a structure which updates the determination table TB suitably after sale.

  Returning to FIG. 2, the paper detection unit 50 detects the paper of the paper P, and includes a light emitting unit 52 and a light receiving unit 54. In this example, a reflective photosensor in which a light emitting unit 52 and a light receiving unit 54 are combined together is used. The light emitting unit 52 is configured by an LED or the like, and irradiates the paper eye detection position T of the paper P with light based on the control signal Sg1 supplied from the control unit 40. The light receiving unit 54 is composed of, for example, a photodiode, and receives the reflected light that is emitted from the light emitting unit 52 and reflected at the paper grain detection position T of the paper P, and supplies a detection voltage corresponding to the amount of reflected light to the control unit 40. To do.

  4A and 4B, the paper eye detection unit 50 is perpendicular to the normal O at the paper eye detection position T of the paper P (perpendicular to the tangent at the paper eye detection position T of the paper P). The sheet is set at a position inclined by a predetermined angle θ with respect to the conveyance direction D1 of the paper P in a plan view (first direction). This is because, when the paper eye detection unit 50 is installed parallel to the normal line O, or installed obliquely with respect to the transport direction D1, the amount of reflected light differs between the case of the vertical eye and the case of the horizontal eye. This is because there is a risk that this will not occur. Note that the paper eye detection unit 50 may be installed in a direction (second direction) orthogonal to the transport direction D1.

  Here, the amount of reflected light in the case of the vertical eye and the case of the horizontal eye will be described. In FIG. 4, a case where the paper eye detection unit 50 is installed on the conveyance direction D1 and obliquely upper left of the paper P will be described. As shown in FIG. 4A, when the grain of the sheet P is orthogonal to the transport direction D1, when light is emitted from the light emitting unit 52 installed obliquely to the upper left, the irradiation light L1 and the grain of the sheet Since the irradiation light L1 hits the paper, a lot of the irradiation light L1 rebounds as reflected light L2. Therefore, the amount of reflected light received by the light receiving unit 54 increases.

  On the other hand, as shown in FIG. 4B, when the grain of the sheet P is parallel to the transport direction D1, when the light is emitted from the light emitting unit 52 installed obliquely to the upper left, the irradiation light L1 and the grain of the sheet Therefore, most of the irradiation light L1 flows along the fiber direction of the paper grain. Therefore, the amount of the reflected light L2 received by the light receiving unit 54 is smaller than that in the case where the irradiation light L1 and the paper grain are orthogonal. In this example, a different amount of reflected light is detected depending on the grain size of the sheet P, and it is determined whether or not the detection voltage corresponding to the detected amount of reflected light exceeds the threshold data Dth of the determination table TB described above. Thus, it is determined whether the paper P is a vertical eye or a horizontal eye.

  Returning to FIG. 2, the control unit 40 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and the image forming apparatus 100, the post-processing apparatus 200, and a large capacity sheet feeding. Each control of the apparatus 300 is performed. Further, the control unit 40 refers to the determination table TB based on the detection voltage (the amount of reflected light) supplied from the paper eye detection unit 50 to determine whether the paper grain of the paper P is a vertical or horizontal eye. Judgment by Then, based on the determination result, the control unit 40 causes the image forming unit 20, the fixing device 24, the post-processing device 200, the large-capacity paper feeding device 300, and the like to perform paper separation control and post-processing control according to the paper size. Feedback control.

  The image forming unit 20 includes a motor 21 and a fan 22 in addition to the above-described photosensitive drum 28 and the like. A control signal Sg2 corresponding to the grain size of the paper P is supplied from the control unit 40 to the motor 21. The motor 21 is rotationally controlled based on the control signal Sg2, and rotates the fan 22 at a predetermined rotational speed. As a result, the fan 22 is switched to an optimum rotational speed corresponding to the grain size of the paper P and is driven to rotate, so that an appropriate wind is blown to the paper P, and the paper separation performance can be further improved. The motor 21 and the fan 22 constitute an example of a separation unit (conveying processing unit).

  The fixing device 24 includes a motor 25 and a fan 26 in addition to a pressure roller and the like. A control signal Sg3 corresponding to the grain size of the paper P is supplied from the control unit 40 to the motor 25. The motor 25 is rotationally controlled based on this control signal Sg3, and rotates the fan 26 at a predetermined rotational speed. As a result, the fan 26 is switched to an optimum rotational speed corresponding to the grain size of the paper P and is driven to rotate, so that an appropriate wind is blown to the paper P, and the paper separation performance can be further improved. The motor 25 and the fan 26 constitute an example of a separation unit (conveying processing unit).

  The post-processing device 200 is connected to the left side surface portion of the image forming apparatus 100, and includes a control unit 60, a communication unit 62, a punching device 64, a stapling device 66, a folding device 68, and a cutting device 69. Note that the punching device 64, the stapling device 66, the folding device 68, and the cutting device 69 can be controlled by the control unit 40 of the image forming apparatus 100 without providing the control unit 60 in the post-processing apparatus 200.

  The communication unit 62 has one end connected to the control unit 60 and the other end connected to the image forming apparatus 100 via the communication cable 11, and performs bidirectional communication with the image forming apparatus 100. In this example, the paper pattern data Dp indicating the paper pattern of the paper P is transmitted from the image forming apparatus 100, and the paper pattern data Dp is received and supplied to the control unit 60.

  The control unit 60 includes a CPU, a ROM, and a RAM. Based on the paper grain data Dp transmitted from the image forming apparatus 100 via the communication unit 62, the punching device 64, the stapling device 66, the half-folding device 68, and the like. Control signals Sa1, Sa2, Sa3, Sa4 for controlling each of the post-processing of the cutting device 69 are generated, and the generated control signals are respectively transmitted to the punching device 64, the stapling device 66, the folding device 68, and the cutting device 69. To supply.

  The punching device 64 punches a plurality of holes at predetermined positions of the paper P conveyed to the post-processing device 200 based on the control signal Sa1 corresponding to the paper grain data Dp supplied from the control unit 60. For example, the punching device 64 changes the number of sheets that can be punched simultaneously depending on whether the paper P of the paper P is vertical or horizontal.

  The stapling device 66 binds the bundle of sheets stacked based on the control signal Sa2 corresponding to the paper eye data Dp supplied from the control unit 60 with the staple needle. For example, the stapling device 66 changes the number of sheets P to be bound at a time or changes the position of the sheets P to be bound depending on whether the sheet P of the sheet P is vertical or horizontal.

  The half-folding device 68 performs a half-folding process for folding the middle portion of the bound sheet bundle based on the control signal Sa3 corresponding to the paper grain data Dp supplied from the control unit 60. For example, the half-folding device 68 changes the number of simultaneous paper folding depending on whether the paper P of the paper P is vertical or horizontal.

  The cutting device 69 cuts the sheet bundle based on the control signal Sa4 corresponding to the paper grain data Dp supplied from the control unit 60. For example, the cutting device 69 changes the number of sheets that can be cut simultaneously depending on whether the sheet P of the paper P is vertical or horizontal.

  The large-capacity paper feeding device 300 is connected to the right side surface portion of the image forming apparatus 100 and is connected to the image forming apparatus 100 via the communication cable 71. The large-capacity paper feeding device 300 includes a control unit 80, a paper eye detection unit 76, a motor 70, and a fan 72. The motor 70 and the fan 72 constitute an example of a conveyance processing unit (separation unit). The paper eye detection unit 76 includes a light emitting unit 77 and a light receiving unit 78 and is installed in the paper feed tray 74 as will be described later. The paper eye detection unit 76 will be described later.

  The control unit 80 includes a CPU, a ROM, and a RAM, and determines the paper size of the paper P stored in the large-capacity paper feeding device 300 based on the detection voltage supplied from the paper eye detection unit 76. Based on the determination result, a control signal Sp for controlling the rotational speed of the fan 72 that performs paper separation is generated and supplied to the motor 70. The motor 70 drives the fan 72 at a predetermined rotational speed based on the control signal Sp supplied from the control unit 80. As a result, an optimum air volume corresponding to the grain size of the paper P is blown from the fan 72 to the paper P, and the paper P is smoothly separated and supplied to the image forming apparatus 100 one by one.

[Configuration example of the paper detection unit installed in the large-capacity paper feeder]
Next, the paper eye detection unit 76 installed in the large-capacity paper feeder 300 will be described. First, the configuration of the large capacity sheet feeder 300 will be briefly described. As shown in FIGS. 5A and 5B, the large-capacity paper feeding device 300 has a paper feeding tray 74, and a large amount of paper is stored in the paper feeding tray 74. Fans 72, 72 as air blowing means are disposed at both ends in the width direction orthogonal to the conveyance direction D 1 of the paper P. Although a fan is also installed on the conveyance direction D1 side, it is omitted for convenience in FIG. An opening 73 for blowing wind is provided in the upper part of the fans 72 and 72. When the fans 72 are driven, wind is blown from the opening 73 to the upper sheet P, and the sheets P are separated one by one.

  As shown in FIG. 5B, the paper detection unit 76 is at a position inclined by a predetermined angle θ with respect to the normal O at the paper detection position T of the paper P, and is seen in a plan view. It is installed in a direction parallel to the transport direction D1 of the paper P. This is because, when the paper eye detection unit 76 is installed parallel to the normal line O, or is installed obliquely with respect to the transport direction D1, the amount of reflected light L2 when the paper P is vertical and the horizontal eye This is because there may be no difference between the amount of the reflected light L2 and the amount of the reflected light L2. The paper grain detector 76 is attached to, for example, a side wall (not shown) constituting the paper feed tray 74.

[Configuration example of the paper detection unit installed in the image forming apparatus]
In the example of the large-capacity paper feeding device 300 described above, the paper eye of the flat paper P that is not curved is detected. However, the paper eye of the paper P is detected even in the curved portion where the paper P is curved. can do. Below, the case where the paper eye detection part 50 is installed in the vicinity of the photosensitive drum 28 will be described.

  As shown in FIGS. 6A and 6B, the toner image is transferred onto the paper P in the transfer section 29 of the photosensitive drum 28. The sheet P on which the toner image is transferred is curved along the peripheral surface of the photosensitive drum 28 by the transfer process in the transfer unit 29. The curved sheet P is separated from the photoconductive drum 28 by a separation function such as a separation unit or air blowing, and is conveyed to the fixing device 24.

  As shown in FIG. 6B, the paper grain detection unit 50 is provided on the downstream side in the transport direction D1 of the transfer unit 29 and obliquely below the photosensitive drum 28 with a predetermined interval. . At this time, the paper detection unit 50 is inclined by a predetermined angle θ with respect to the normal O at the paper detection position T of the paper P, and in the transport direction D1 of the paper P when viewed in plan. It is installed in a parallel position. The irradiation light L1 (optical axis) of the light emitting unit 52 of the paper eye detection unit 50 is preferably inclined with respect to the normal line O at the paper eye detection position T in a range of 30 ° to 40 °, for example. Further, the paper eye detection unit 50 may be installed in a direction orthogonal to the transport direction D1.

[Operation Example of Image Forming System (Part 1)]
Next, an example of the operation of the image forming system GS according to the present invention will be described. In this example, the same paper P is stored in the paper feed tray 36 that feeds the paper P. As shown in FIG. The case where 50 is installed is demonstrated. In the following, the conveyance direction D1 of the paper P is the vertical eye of the paper P, the direction orthogonal to the conveyance direction D1 is the horizontal eye of the paper P, and the paper eye detection unit 50 is installed in parallel with the conveyance direction D1. And

  The user uses the menu screen of the operation display unit 30 to select whether the same paper size or different paper size is in the paper feed tray 36. Assume that the user can grasp and confirm the grain of the paper P before the paper P is fed. When the user selects an item indicating that the same sheet of paper is in the paper feed tray 36, the control unit 40 operates the paper feed tray 36 to feed paper in step S100 as shown in FIG. Judgment is made based on the input from the display unit 30, and the setting data of the paper stored in the paper feed tray 36 is acquired from the memory unit 42 or the like. Setting data is provided for each sheet, and the setting data includes, for example, information such as paper type and amount of paper.

  In step S102, when the control unit 40 acquires the setting data corresponding to the paper P, the control unit 40 refers to the determination table TB stored in the memory unit 42, and sets the threshold data Dth corresponding to the paper type included in the acquired setting data. Obtain (see FIG. 3).

  In step S <b> 104, the control unit 40 detects the paper eye of the paper P being conveyed by the paper eye detection unit 50 installed in the vicinity of the photosensitive drum 28. Specifically, the irradiation light L1 is emitted from the light emitting unit 52 to the sheet detection position of the paper P, and the detection voltage (detection data Dd) corresponding to the reflected light amount of the reflected light L2 received by the light receiving unit 54 is acquired. .

  In step S106, the control unit 40 compares the acquired detection data Dd with the threshold data Dth acquired from the determination table TB, and determines whether or not the detection data Dd is larger than the threshold data Dth. When it is determined that the detection data Dd is larger than the threshold data Dth, the process proceeds to step S108, and when it is determined that the detection data Dd is smaller than the threshold data Dth, the process proceeds to step S112.

  In step S108, when the control unit 40 determines that the detection data Dd is larger than the threshold data Dth, the control unit 40 determines that the paper of the paper P during the image forming process (conveyance) is a horizontal eye. This is because, when the irradiation light L1 is irradiated from a position parallel to the transport direction D1, the irradiation light L1 is reflected by the paper when the paper is horizontal, and the detection data Dd (the amount of reflected light) is greater than the threshold data Dth. Because it grows.

  When the control unit 40 determines in step S110 that the sheet is a horizontal line, it generates control signals Sg2, Sg3, etc. according to the horizontal line and generates a control signal Sg2, Sg3, etc. The motor 25 is fed back to perform paper separation processing corresponding to the horizontal eye. As a result, an optimum wind corresponding to the grain size of the paper P is blown from the fans 22 and 26. If the control unit 40 determines that the post-processing process is set for the paper P during image formation based on the input information from the operation display unit 30, the paper eye data Dp indicating the horizontal eye is set. Is generated and supplied to the post-processing apparatus 200, and post-processing corresponding to the horizontal eye is performed.

  On the other hand, in step S112, when the control unit 40 determines that the detection data Dd is smaller than the threshold data Dth, the control unit 40 determines that the grain of the sheet P during the image forming process (conveyance) is a vertical eye. This is because, when the irradiation light L1 is irradiated from a position parallel to the transport direction D1, the irradiation light L1 flows along the fiber direction when the paper is horizontal, and the detection data Dd (reflected light amount) is from the threshold data Dth. It is also because it becomes small.

  If the control unit 40 determines in step S114 that the paper is vertical, the control unit Sg2, Sg3 and the like corresponding to the vertical eye are generated, and the motor 21 and the fixing device of the image forming unit 20 having the paper separation function are generated. The paper is fed back to 24 motors 25 to perform paper separation processing corresponding to the vertical eye. As a result, an optimum wind corresponding to the grain size of the paper P is blown from the fans 22 and 26. Further, when the control unit 40 determines that the post-processing process is set for the paper P during image formation based on the input information from the operation display unit 30, the paper eye data indicating the vertical eye Dp is generated and supplied to the post-processing apparatus 200, and post-processing corresponding to the vertical eye is performed.

  In step S116, the control unit 40 determines whether or not the copying is completed. If it is determined that copying has been completed, it is determined that a series of jobs have been completed, and input of the next job is awaited. On the other hand, if it is determined that the copying has not ended, the process proceeds to step S118.

  In step S118, the control unit 40 determines whether the paper feed tray 36 has been changed. If it is determined that the paper feed tray 36 has been changed, the process returns to step S100, and the paper of the paper P stored in the changed paper feed tray 36 is determined by the above-described paper eye determination method. On the other hand, when it is determined that the paper feed tray 36 has not been changed, the type of the paper P is not changed, so the determination result of the paper eye determined in the above-described steps S100 to S114 is used as it is, and the paper P Paper separation processing and post-processing corresponding to the paper size are performed.

[Operation Example of Image Forming System (Part 2)]
Next, an example of the operation of the image forming apparatus 100 when the same paper P is not stored in the paper feed tray 36 will be described. In this case, on the menu screen of the operation display unit 30, an item button indicating that the same paper P is not in the paper feed tray 36 is selected. Since the process from step S200 to S216 shown in FIG. 8 is the same as the process from step S100 to S116 described above, a description thereof will be omitted.

  As shown in FIG. 8, in step S218, the control unit 40 determines whether or not the paper feed tray 36 has been changed. If it is determined that the paper feed tray 36 has been changed, the grain of the paper P stored in the paper feed tray 36 may also be different, so the process returns to step S200 and the changed paper feed tray 36 is changed. The paper of the stored paper P is determined by the above-described paper determination method. On the other hand, even when it is determined that the paper feed tray 36 has not been changed, the paper of the paper P in the selected paper feed tray 36 may be different from each other. The paper size of the paper P is determined again based on Dd and the threshold data Dth.

  Note that, in the above-described example, the eyes of the paper P in the paper feed tray 36 are determined one by one, but it is also possible to limit the number of paper P for which the paper eyes are determined in advance. This is because if the grain number of the predetermined number of sheets P is continuously the same, it is highly likely that the grain numbers of the subsequent sheets P are also the same. With this setting method, it is possible to improve the speed of image forming processing and improve productivity.

  As described above, according to the first embodiment, the amount of reflected light on the paper P is detected by the paper-eye detection units 50 and 76, and is detected by the paper-eye detection units 50 and 76 by the control units 40 and 80. The paper size of the paper P is determined based on the amount of reflected light, and the determination result is reflected in paper separation control of the image forming unit 20, the fixing device 24, the large-capacity paper feeding device 300, and the post-processing control of the post-processing device 200. Therefore, paper separation performance and post-processing performance can be optimized for each paper. As a result, paper separation performance and post-processing performance can be further improved.

  In addition, according to the first embodiment, the grain of the sheet P having a curved portion can also be detected, so that it is possible to detect the grain of the sheet at various locations and the design. The degree of freedom can be improved.

<2. Second Embodiment>
In the first embodiment described above, the paper grain detection unit is configured as one set. However, the second embodiment is different in that the paper grain detection unit is configured as two sets. Since the configuration of the other image forming system GS is the same as that of the first embodiment, common components are denoted by the same reference numerals, and detailed description thereof is omitted.

[Example of block configuration of image forming system]
As shown in FIG. 9, the image forming system GS includes an image forming apparatus 100, a post-processing apparatus 200, and a large capacity sheet feeding apparatus 300. The image forming apparatus 100 includes paper eye detection units 50 </ b> A and 50 </ b> B for detecting paper eyes such as paper P transferred by the photosensitive drum 28 and paper P on which an image is fixed by the fixing device 24. The post-processing device 200 includes paper eye detection units 76A and 76B for detecting the paper eye of the uppermost paper P stored in the paper feed tray 74. In the following description, the paper eye detection units 50A and 50B and the paper eye detection units 76A and 76B have the same configuration, and therefore the paper eye detection units 76A and 76B will be described for convenience.

  The paper grain detection unit 76A is a position inclined by a predetermined angle θ with respect to the normal C1 at the paper grain detection position T of the paper P (see FIG. 4), and the conveyance direction of the paper P when viewed in plan. It is installed in a direction parallel to D1 (see FIG. 10). Hereinafter, a direction parallel to the transport direction D1 is defined as an X direction (first direction), and a direction orthogonal to the transport direction D1 is defined as a Y direction (second direction). The paper grain detection unit 76A includes a light emitting unit 77A and a light receiving unit 78A. The light emitting unit 77A irradiates the light detection position T of the paper P from the obliquely upper side of the paper P with the irradiation light L1x. The light receiving unit 78A receives the reflected light in the X direction of the irradiation light L1x reflected at the paper grain detection position T of the paper P, and supplies a detection voltage (detection data Ddx) according to the reflected light amount to the control unit 40. Note that the paper grain detector 76A constitutes an example of a first paper grain detector.

  The paper eye detection unit 76B is a position inclined by a predetermined angle θ with respect to the normal C1 at the paper eye detection position T of the paper P (see FIG. 4), and the paper P is transported in a plan view. It is provided on the Y direction orthogonal to D1 (see FIG. 10). The paper grain detection unit 76B includes a light emitting unit 77B and a light receiving unit 78B. The light emitting unit 77B irradiates the light detection position T of the paper P from obliquely above the paper P with the irradiation light L1y. The light receiving unit 78B receives the reflected light in the Y direction of the irradiation light L1y reflected at the paper grain detection position T of the paper P, and supplies a detection voltage (detection data Ddy) corresponding to the reflected light amount to the control unit 40. Note that the paper grain detection unit 76B constitutes an example of a second paper grain detection unit.

  The control unit 80 compares the voltage value of the detection data Ddx supplied from the paper grain detection unit 76A with the voltage value of the detection data Ddy supplied from the paper grain detection unit 76B, and supplies the voltage based on the comparison result. It is determined whether the grain of the paper P stored in the paper tray 74 is a vertical grain or a horizontal grain. Then, a control signal corresponding to the paper pattern of the determination result is generated and supplied to the motor 70, and the fan 72 is driven to rotate at a rotational speed corresponding to the paper pattern, and the air optimized according to the paper pattern is blown. .

[Operation Example of Image Forming System (Part 3)]
Next, an example of the operation of the image forming system GS according to the second embodiment of the present invention will be described. In the following, a case will be described in which the eye of the paper P stored in the paper feed tray 74 of the large capacity paper feeder 300 is detected and the detected content is fed back to the paper separation control.

  First, the user selects whether the same paper P or different paper P is in the paper feed tray 74 on the menu screen of the operation display unit 30. When the user selects an operation button indicating that the same sheet of paper is in the paper feed tray 74, as shown in FIG. 11, in step S300, the control unit 80 causes the paper P detection unit 76A to transfer the paper P. Detection data Ddx in the X direction at the paper eye detection position T is obtained, and detection data Ddy in the Y direction at the paper eye detection position T of the paper P is obtained from the paper eye detection unit 76B.

  In step S302, the control unit 80 compares the acquired detection data Ddx in the X direction with the detection data Ddy in the Y direction, and the voltage value of the detection data Ddy in the Y direction is larger than the voltage value of the detection data Ddx in the X direction. Determine whether or not. If it is determined that the voltage value of the detection data Ddy in the Y direction is larger than the voltage value of the detection data Ddx in the X direction, the process proceeds to step S304, and the voltage value of the detection data Ddy in the Y direction is equal to the detection data Ddx in the X direction. If it is determined that the value is smaller than the voltage value, the process proceeds to step S308.

  In step S304, if the voltage value of the detection data Ddy in the Y direction is larger than the voltage value of the detection data Ddx in the X direction, the control unit 80 determines that the paper pattern of the paper P is a vertical pattern. This is because when the irradiation light Lly from the Y direction is orthogonal to the fiber direction, the irradiation light L1y bounces off the paper and the amount of reflected light (detection data Ddy) increases, and the irradiation light L1x from the X direction. This is because the amount of reflected light (detection data Ddx) decreases when flowing along the fiber direction.

  In step S306, if the control unit 80 determines that the sheet P of the sheet P is a vertical eye, the control unit 80 generates a control signal corresponding to the vertical eye and supplies (feeds back) the control signal to the motor 70 having paper separation performance. As a result, the fan 72 rotates at a rotational speed corresponding to the vertical eye and blows the optimized wind onto the paper P.

  On the other hand, in step S308, when the voltage value of the detection data Ddy in the Y direction is smaller than the voltage value of the detection data Ddx in the X direction, the control unit 80 determines that the grain of the paper P is a horizontal eye. This is because, when the irradiation light Lly from the Y direction is parallel to the fiber direction, the irradiation light Lly flows along the grain of the paper, so that the amount of reflected light (detection data Ddy) becomes small, and the irradiation light L1x from the X direction. This is because when the beam is orthogonal to the fiber direction, the irradiation light L1y bounces off the paper and the amount of reflected light (detection data Ddx) increases.

  In step S310, if the control unit 80 determines that the sheet P of the sheet P is a horizontal eye, the control unit 80 generates a control signal corresponding to the horizontal eye and supplies (feeds back) the control signal to the motor 70 having paper separation performance. As a result, the fan 72 rotates at a rotation speed corresponding to the horizontal eye, and blows the optimized wind onto the paper P.

  In step S312, the control unit 80 determines whether or not copying has ended. If it is determined that copying has been completed, it is determined that a series of jobs have been completed, and input of the next job is awaited. On the other hand, if it is determined that the copying has not ended, the process proceeds to step S314.

  In step S314, the control unit 80 determines whether or not the paper feed tray 74 has been changed. If it is determined that the paper feed tray 74 has been changed, the process returns to step S300, and the paper of the paper P stored in the changed paper feed tray 74 is determined by the above-described paper eye determination method. On the other hand, if it is determined that the paper feed tray 74 has not been changed, the type of the paper P is not changed, so the judgment result of the paper eye determined in the above-described steps S300 to S310 is used as it is, and the paper P Paper separation processing and post-processing corresponding to the paper size are performed.

  In the above description, an example has been described in which the paper grain information of the paper P determined by the control unit 80 of the large-capacity paper feeder 300 is fed back only to the paper separation function unit of the large-capacity paper feeder 300. It is not limited to. For example, the paper of the paper P determined by the control unit 80 can be transmitted to the image forming apparatus 100 or the post-processing apparatus 200 as the paper grain data Dp. In this case, the control unit 40 of the image forming apparatus 100 changes the control of the paper separation performance of the photosensitive drum 28 and the fixing device 24 described above based on the paper eye data Dp transmitted from the large-capacity paper feeding device 300. To do. Similarly, the control unit 60 of the post-processing device 200 performs the above-described punching processing by the punching device 64 and stapling processing by the stapling device 66 based on the paper grain data Dp transmitted from the large-capacity paper feeding device 300. Change the post-processing. Further, the same processing as that of the above-described paper detection units 76A and 76B can be applied to the paper detection units 50A and 50B provided in the image forming apparatus 100.

[Operation Example of Image Forming System (Part 4)]
Next, an example of the operation of the image forming system GS when the same paper P is not stored in the paper feed tray 74 will be described. In this case, on the menu screen of the operation display unit 30, an item button indicating that the same paper P is not in the paper feed tray 74 is selected. Since the process from step S400 to S412 shown in FIG. 12 is the same as the process from step S300 to S312 described above, the description thereof is omitted.

  As shown in FIG. 12, in step S414, the control unit 80 determines whether or not the paper feed tray 74 has been changed. If it is determined that the paper feed tray 74 has been changed, the grain of the paper P stored in the paper feed tray 74 may also be different, so the process returns to step S400 and the changed paper feed tray 74 is changed. The paper of the stored paper P is determined by the above-described paper determination method. On the other hand, even when it is determined that the paper feed tray 74 has not been changed, the paper of the paper P in the selected paper feed tray 74 may be different from each other. The X-direction detection data Ddx at the P paper-eye detection position T is compared with the Y-direction detection data Ddy, and the paper eye of the paper P is determined. The processing after this determination is the same as the processing from the above steps S304 to S312.

  As described above, according to the second embodiment, since the paper eye of the paper P is determined using the two paper eye detection units 76A and 76B (50A and 50B), the threshold data Dth is not used. In addition, it is possible to determine the paper size of the paper P. This eliminates the need for creating threshold data Dth in advance, reduces the memory capacity, and speeds up the paper grain determination process. In addition, since the two paper eye detection units 76A and 76B (50A and 50B) are used, it is possible to improve the accuracy of the paper eye judgment as compared with the case where one paper eye detection unit 76 is used.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. For example, in the first and second embodiments described above, an example in which the paper-sheet detecting unit 76 is installed in the large-capacity paper feeding device 300 has been described. However, the paper-eye detecting unit is provided in the paper feeding tray 36 of the image forming apparatus 100. May be installed. At this time, as described in the second embodiment, two sets of paper grain detection units may be installed in the paper transport unit of the post-processing apparatus 200. Further, a paper grain detection unit may be installed inside the post-processing apparatus 200. Further, the paper eye detection units 50 and 76 may be installed only in one of them.

  Furthermore, in the first embodiment, it is possible to provide a moving mechanism capable of moving the paper grain detection unit 50 in a direction parallel to the transport direction D1 and an orthogonal direction orthogonal to this direction. As a result, it is possible to acquire the detection voltages in two directions, ie, the conveyance direction D1 of the paper eye detection position T and the direction orthogonal to the paper eye detection position T without providing two paper eye detection units.

DESCRIPTION OF SYMBOLS 20 ... Image formation part, 24 ... Fixing device (conveyance processing part), 28 ... Photosensitive drum (conveyance processing part), 30 ... Operation display part, 40, 60, 80 ... Control , 42... Memory unit, 50, 76... Paper detection unit, 100... Image forming apparatus, 200 .. post-processing apparatus, 300. Transport direction, GS ... image forming system, TB ... table, P ... paper, Dth ... threshold data

Claims (10)

An image forming apparatus for forming a predetermined image on paper,
A conveyance processing unit for conveying the paper;
Provided in a first direction parallel to the paper transport direction or in a second direction perpendicular to the first direction, and from the position inclined by a predetermined angle with respect to the normal line at the paper-sheet detection position of the paper A paper detection unit that irradiates the paper detection position with light and detects the amount of reflected light reflected by the irradiation at the paper detection position;
A control unit that determines a paper pattern indicating a fiber direction of the paper based on the amount of the reflected light detected by the paper detection unit, and controls paper separation performance in the transport processing unit based on the determination result; An image forming apparatus comprising: The conveyance processing unit has a curved portion,
2. The image formation according to claim 1, wherein the paper grain detection unit irradiates the light to the paper grain detection position in the curved part of the paper that is conveyed along the curved part. 3. apparatus. A table for storing threshold data used when judging the paper size of the paper set for each paper type;
The controller is
Threshold data corresponding to the paper is acquired from the table, the acquired threshold data is compared with detection data corresponding to the amount of reflected light detected by the paper detection unit, and based on the comparison result The image forming apparatus according to claim 1, wherein a paper eye indicating a fiber direction of the paper is determined. The paper detection unit
A first paper grain detection unit provided in a first direction parallel to the paper transport direction;
A second paper grain detector provided in a second direction orthogonal to the first direction,
The controller is
Comparing the amount of reflected light in the first direction detected by the first paper grain detector with the amount of reflected light in the second direction detected by the second paper grain detector The image forming apparatus according to any one of claims 1 to 3, wherein a paper pattern indicating a fiber direction of the paper is determined based on the comparison result. The image forming apparatus according to claim 1, further comprising: a moving mechanism that moves the paper grain detection unit between the first direction and the second direction. . The conveyance processing unit includes a photosensitive drum that transfers an image to the paper, and a separation unit that separates the paper from the photosensitive drum.
The image forming apparatus according to any one of claims 1 to 5, wherein the control unit changes transfer separation control of the separation unit based on the paper grain detection result. The conveyance processing unit includes a fixing roller that fixes the image on the sheet, and a separation unit that separates the sheet from the fixing roller.
The image forming apparatus according to claim 1, wherein the control unit changes fixing separation control of the separation unit based on the paper detection result. The image forming apparatus is connected to a post-processing apparatus that performs predetermined post-processing on the paper on which the image is formed,
The post-processing device includes a post-processing unit that performs predetermined post-processing on the paper,
The post-processing unit changes the control of the post-processing based on a determination result of the sheet size of the paper supplied from the control unit of the image forming apparatus. The image forming apparatus according to claim 1. A paper feeding device that contains paper and feeds the paper to an image forming apparatus,
A transport processing section for transporting the paper to the image forming apparatus;
A position that is provided in a first direction parallel to the paper transport direction and / or in a second direction orthogonal to the first direction, and is inclined by a predetermined angle with respect to a normal line at a paper-sheet detection position of the paper Irradiating light to the paper pattern detection position from, and detecting the amount of reflected light reflected at the paper pattern detection position by irradiation,
A control unit that determines a paper pattern indicating a fiber direction of the paper based on the amount of the reflected light detected by the paper detection unit, and controls paper separation performance in the transport processing unit based on the determination result; A sheet feeding device comprising: An image forming system for forming a predetermined image on paper,
A conveyance processing unit for conveying the paper;
A post-processing unit that performs predetermined post-processing on the paper transported by the transport processing unit;
A position that is provided in a first direction parallel to the paper transport direction and / or in a second direction orthogonal to the first direction, and is inclined by a predetermined angle with respect to a normal line at a paper-sheet detection position of the paper Irradiating light to the paper pattern detection position from, and detecting the amount of reflected light reflected at the paper pattern detection position by irradiation,
Based on the amount of reflected light detected by the paper detection unit, a paper pattern indicating the fiber direction of the paper is determined, and based on the determination result, paper separation control in the transport processing unit and the post-processing unit An image forming system comprising: a control unit that changes control of at least one of the controls.

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