JP2015113214A - Image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation system which can highly accurately perform correction of image formation conditions and inspection of continuous form paper by correctly reading a correction and inspection image formed on the continuous form paper.SOLUTION: An image formation system 100 comprises: an image formation part 40 which forms an image on continuous form paper P; a take-up device 5 which takes up the continuous form paper P on which the image is formed by the image formation part 40; a correction and inspection image reading part 84 which includes a line sensor for reading a correction and inspection image formed on the continuous form paper P by the image formation part 40; a first sagging formation device 3 which forms a first sagging portion P1 in a gravity direction on the continuous form paper P; a first sagging amount detection part 80 which detects a first sagging amount of the first sagging portion P1; a reading transportation part 86 which changes a transport speed of the continuous form paper P in the correction and inspection image reading part 84; and a control part which controls the reading transportation part 86 so as to change the transport speed of the continuous form paper P in the correction and inspection image reading part 84 in accordance with the first sagging amount detected by the first sagging amount detection part 80.

Description

  The present invention relates to an image forming system.

  In general, an image forming apparatus (printer, copier, facsimile, etc.) using an electrophotographic process technology generates an electrostatic latent image by irradiating (exposing) a charged photoconductor with a laser beam based on image data. Form. Then, by supplying toner from the developing device to the photosensitive member (image carrier) on which the electrostatic latent image is formed, the electrostatic latent image is visualized to form a toner image. Further, after the toner image is directly or indirectly transferred to the paper, it is fixed by heating and pressurizing to form an image on the paper. In an image forming apparatus, an image is usually formed on paper that is separated one by one (also referred to as “single-leaf paper”), but continuous paper such as continuous roll paper or folded paper (hereinafter referred to as “continuous paper”). It is also possible to form an image on ().

  In addition, when an image is formed on continuous paper by the image forming apparatus, a correction image for monitoring the density, gradation, positional deviation, etc. of the image, or an inspection image for inspecting the printing state of the continuous paper ( Hereinafter, the correction image or the inspection image is simply referred to as “correction inspection image”) at an arbitrary position on the continuous paper, and an image reading device (for example, provided on the downstream side of the image forming apparatus in the paper transport direction) There is known an image forming system which is read by a line sensor. Depending on the reading result of the corrected inspection image, the image forming conditions are corrected and the continuous paper is inspected.

  In addition, as an image forming technique when forming an image on continuous paper, an image forming unit and an image forming unit between the image forming unit and a winding unit that winds the continuous paper on which the image is formed by the image forming unit. There has been proposed a technique of providing a buffer unit that absorbs a difference in conveyance speed of continuous paper generated between the winding unit and the winding unit (see, for example, Patent Document 1).

JP 2000-25996 A

  However, in the image forming system, the image forming speed in the image forming apparatus (corresponding to the continuous paper transport speed in the image forming apparatus) and the reading speed in the image reading apparatus (corresponding to the continuous paper transport speed in the image reading apparatus) If they are different, there is a problem that the continuous paper is bent or pulled due to the difference in the conveyance speed, and the image for correction inspection formed on the continuous paper cannot be read accurately in the image reading apparatus. In addition, when a correction inspection image for color correction is formed on continuous paper, if the correction inspection image is read immediately after the heating process (fixing process), the color of the read correction inspection image is Unlike the original one, there is a problem that the color of the image for correction inspection may not be accurately read in the image reading apparatus. As described above, if the image for correction inspection cannot be accurately read by the image reading apparatus, thereafter, correction of image forming conditions and inspection of continuous paper cannot be performed with high accuracy.

  In order to solve the above problem, it is conceivable to read the correction inspection image with high resolution using an image reading unit such as a camera. However, the image processing of the read correction inspection image becomes complicated, or the image Another problem arises that the cost of the reading unit is significantly increased.

  An object of the present invention is to provide an image forming system capable of accurately reading an image for correction inspection formed on continuous paper and correcting image forming conditions and inspection of continuous paper with high accuracy.

An image forming system according to the present invention includes:
An image forming unit for forming an image on continuous paper;
A take-up unit that is provided on the downstream side of the image forming unit in the conveying direction of the continuous paper and winds up the continuous paper on which an image is formed by the image forming unit;
Corrected inspection having a line sensor that is provided on the downstream side of the image forming unit and the upstream side of the winding unit in the conveyance direction of the continuous paper, and that reads the image for correction inspection formed on the continuous paper by the image forming unit. An image reading unit;
A first slack forming unit provided on the downstream side of the image forming unit in the conveyance direction of the continuous paper and the upstream side of the correction inspection image reading unit, and forming a first slack portion in the gravity direction on the continuous paper;
A first slack amount detection unit for detecting a first slack amount of the first slack portion;
A conveyance speed changing unit that changes a conveyance speed of the continuous paper in the correction inspection image reading unit;
A control unit that controls the transport speed changing unit to change the transport speed of the continuous paper in the correction inspection image reading unit according to the first slack amount detected by the first slack amount detecting unit; ,
It is characterized by providing.

  According to the present invention, since the first slack portion is formed on the continuous paper by the first slack forming unit, the conveyance speed difference generated between the image forming unit and the correction inspection image reading unit is absorbed. There is no deflection or pulling of the continuous paper due to the difference in the conveyance speed, and the corrected inspection image formed on the continuous paper can be accurately read in the corrected inspection image reading unit. Further, since the continuous paper subjected to the heating process (fixing process) is naturally cooled while being conveyed by the first slack forming unit, even when a correction inspection image for color correction is formed. Thus, the color of the corrected inspection image can be prevented from changing, and the color of the corrected inspection image can be accurately read by the corrected inspection image reading unit. As described above, the corrected inspection image formed on the continuous paper can be accurately read, and the correction of the image forming conditions and the inspection of the continuous paper can be performed with high accuracy.

1 is a diagram schematically showing an overall configuration of an image forming system according to an embodiment. FIG. 3 is a diagram illustrating a main part of a control system of the image forming apparatus according to the present embodiment. It is a figure which shows the example of the image for correction | amendment inspection formed on continuous paper. 5 is a flowchart illustrating an example of a conveyance control operation of the image forming system according to the present embodiment. 5 is a flowchart illustrating an example of air blowing control operation of the image forming system according to the present embodiment. It is a figure explaining the 1st slack amount of the continuous paper in a 1st slack formation apparatus. It is a figure which shows the correspondence of the conveyance speed of a continuous paper, the 1st slack amount, and the ventilation volume of cooling air. It is a figure which shows the correspondence of the conveyance speed of a continuous paper, the 1st slack amount, and the ventilation volume of cooling air.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.
[Configuration of Image Forming System 100]
FIG. 1 is a diagram schematically showing an overall configuration of an image forming system 100 according to an embodiment of the present invention. FIG. 2 shows a main part of a control system of the image forming apparatus 2 according to the present embodiment. The image forming system 100 is a system that uses the continuous paper P or the paper S as a recording medium and forms an image on the continuous paper P or the paper S.

  As shown in FIG. 1, the image forming system 100 includes a paper feeding device 1, an image forming device 2, and a first slack forming device from the upstream side along the transport direction of the continuous paper P (hereinafter also referred to as the paper transport direction). 3 (first slack forming portion), a second slack forming device 4 (second slack forming portion), and a winding device 5 (winding portion) are connected. The sheet feeding device 1, the first slack forming device 3, the second slack forming device 4, and the winding device 5 are used when an image is formed on the continuous paper P. In this embodiment, an example in which the image forming apparatus 2 is a color image forming apparatus will be described. However, the image forming apparatus 2 may be a monochrome image forming apparatus.

  The paper feeding device 1 is a device that feeds the continuous paper P to the image forming apparatus 2. In the casing of the paper feeding device 1, as shown in FIG. 1, a roll-shaped continuous paper P is wound around a support shaft and held rotatably. The paper feeding device 1 conveys the continuous paper P wound around the support shaft to the outside at a constant speed via a plurality of rollers (for example, a feeding roller and a paper feeding roller). The sheet feeding operation of the sheet feeding apparatus 1 is controlled by the control unit 101 provided in the image forming apparatus 2. In the paper feeding device 1, the continuous paper P is not necessarily held in a roll shape, and may be held in a folded state. Although only one continuous paper P is shown in FIG. 1, a plurality of continuous papers may be held in the housing of the paper feeding device 1.

  The image forming apparatus 2 is an intermediate transfer type color image forming apparatus using electrophotographic process technology. That is, the image forming apparatus 2 transfers the toner images of Y (yellow), M (magenta), C (cyan), and K (black) formed on the photosensitive drum 413 to the intermediate transfer belt 421 (primary transfer). Then, after superposing four color toner images on the intermediate transfer belt 421, the image is formed by transferring (secondary transfer) onto the continuous paper P or paper S fed from the paper feeding device 1. .

  In the image forming apparatus 2, photosensitive drums 413 corresponding to four colors of YMCK are arranged in series in the running direction of the intermediate transfer belt 421, and each color toner image is sequentially transferred to the intermediate transfer belt 421 in one procedure. Tandem system is adopted.

  As shown in FIG. 2, the image forming apparatus 2 includes an image reading unit 10, an operation display unit 20, an image processing unit 30, an image forming unit 40, a paper transport unit 50, a fixing unit 60, and a control unit 101.

  The control unit 101 includes a CPU (Central Processing Unit) 102, a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, and the like. The CPU 102 reads out a program corresponding to the processing content from the ROM 103 and develops it in the RAM 104, and centrally controls the operation of each block of the image forming apparatus 2 in cooperation with the developed program. At this time, various data stored in the storage unit 72 is referred to. The storage unit 72 includes, for example, a nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive.

  The control unit 101 transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 71. Do. For example, the control unit 101 receives image data transmitted from an external device, and forms an image on the continuous paper P or the paper S based on the image data (input image data). The communication unit 71 is composed of a communication control card such as a LAN card, for example.

  The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder), a document image scanning device 12 (scanner), and the like.

  The automatic document feeder 11 transports the document D placed on the document tray by a transport mechanism and sends it out to the document image scanning device 12. The automatic document feeder 11 can continuously read images (including both sides) of a large number of documents D placed on the document tray all at once.

  The document image scanning device 12 optically scans a document conveyed on the contact glass from the automatic document feeder 11 or a document placed on the contact glass, and reflects light from the document to a CCD (Charge Coupled Device). ) An image is formed on the light receiving surface of the sensor 12a, and an original image is read. The image reading unit 10 generates input image data based on the reading result by the document image scanning device 12. The input image data is subjected to predetermined image processing in the image processing unit 30.

  The operation display unit 20 is configured by, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22. The display unit 21 displays various operation screens, image states, operation states of functions, and the like according to a display control signal input from the control unit 101. The operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs an operation signal to the control unit 101.

  The image processing unit 30 includes a circuit that performs digital image processing on input image data according to initial settings or user settings. For example, the image processing unit 30 performs gradation correction based on the gradation correction data (gradation correction table) under the control of the control unit 101. Further, the image processing unit 30 performs various correction processes such as color correction and shading correction, a compression process, and the like on the input image data in addition to the gradation correction. The image forming unit 40 is controlled based on the image data subjected to these processes.

  Based on the input image data, the image forming unit 40 is an image forming unit 41Y, 41M, or image forming unit 41Y, 41M for forming an image with each color toner of Y component, M component, C component, and K component, or a correction inspection image described later. 41C, 41K, intermediate transfer unit 42, and the like.

  The Y component, M component, C component, and K component image forming units 41Y, 41M, 41C, and 41K have the same configuration. For convenience of illustration and explanation, common constituent elements are denoted by the same reference numerals, and Y, M, C, or K are added to the reference numerals when distinguished from each other. In FIG. 1, only the components of the Y-component image forming unit 41Y are denoted by reference numerals, and the constituent elements of the other image forming units 41M, 41C, and 41K are omitted.

  The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, a drum cleaning device 415, and the like.

  The photosensitive drum 413 has an undercoat layer (UCL) and a charge generation layer (CGL) on the peripheral surface of an aluminum conductive cylinder (aluminum tube) having a drum diameter of 80 mm, for example. It is a negatively charged organic photoconductor (OPC) in which a generation layer (CTL) and a charge transport layer (CTL) are sequentially stacked. The charge generation layer is made of an organic semiconductor in which a charge generation material (for example, phthalocyanine pigment) is dispersed in a resin binder (for example, polycarbonate), and generates a pair of positive charges and negative charges by exposure by the exposure device 411. The charge transport layer consists of a material in which a hole transport material (electron donating nitrogen-containing compound) is dispersed in a resin binder (for example, polycarbonate resin), and transports positive charges generated in the charge generation layer to the surface of the charge transport layer. To do.

  The control unit 101 controls the drive current supplied to a drive motor (not shown) that rotates the photosensitive drum 413, so that the photosensitive drum 413 rotates at a constant peripheral speed.

  The charging device 414 uniformly charges the surface of the photoconductive drum 413 to a negative polarity. The exposure device 411 is composed of, for example, a semiconductor laser, and irradiates the photosensitive drum 413 with laser light corresponding to the image of each color component. A positive charge is generated in the charge generation layer of the photosensitive drum 413 and is transported to the surface of the charge transport layer, whereby the surface charge (negative charge) of the photosensitive drum 413 is neutralized. An electrostatic latent image of each color component is formed on the surface of the photosensitive drum 413 due to a potential difference from the surroundings.

  The developing device 412 is a two-component developing type developing device, and attaches toner of each color component to the surface of the photosensitive drum 413 to visualize the electrostatic latent image to form a toner image.

  The drum cleaning device 415 includes a drum cleaning blade that is slidably contacted with the surface of the photosensitive drum 413, and removes transfer residual toner remaining on the surface of the photosensitive drum 413 after primary transfer.

  The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like.

  The intermediate transfer belt 421 is an endless belt, and is stretched around a plurality of support rollers 423 in a loop shape. At least one of the plurality of support rollers 423 is configured by a driving roller, and the other is configured by a driven roller. For example, it is preferable that the roller 423A disposed downstream of the K component primary transfer roller 422 in the belt traveling direction is a drive roller. This makes it easy to keep the belt running speed constant in the primary transfer portion. As the driving roller 423A rotates, the intermediate transfer belt 421 travels in the direction of arrow A at a constant speed.

  The intermediate transfer belt 421 is a belt having conductivity and elasticity, and has a high resistance layer having a volume resistivity of 8 to 11 [log Ω · cm] on the surface. The intermediate transfer belt 421 is rotationally driven by a control signal from the control unit 101. Note that the material, thickness, and hardness of the intermediate transfer belt 421 are not limited as long as they have conductivity and elasticity.

  The primary transfer roller 422 is disposed on the inner peripheral surface side of the intermediate transfer belt 421 so as to face the photosensitive drum 413 of each color component. The primary transfer roller 422 is pressed against the photosensitive drum 413 with the intermediate transfer belt 421 interposed therebetween, thereby forming a primary transfer nip for transferring a toner image from the photosensitive drum 413 to the intermediate transfer belt 421.

  The secondary transfer roller 424 is disposed on the outer peripheral surface side of the intermediate transfer belt 421 so as to face a roller 423B (hereinafter referred to as “backup roller 423B”) disposed on the downstream side of the driving roller 423A in the belt traveling direction. The secondary transfer roller 424 is pressed against the backup roller 423B across the intermediate transfer belt 421, thereby forming a secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the continuous paper P or the paper S. The

  When the intermediate transfer belt 421 passes through the primary transfer nip, the toner images on the photoconductive drum 413 are primarily transferred onto the intermediate transfer belt 421 in sequence. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and an electric charge having a polarity opposite to that of the toner is applied to the back side of the intermediate transfer belt 421 (the side in contact with the primary transfer roller 422). It is electrostatically transferred to the intermediate transfer belt 421.

  Thereafter, when the continuous paper P or paper S passes through the secondary transfer nip, the toner image on the intermediate transfer belt 421 is secondarily transferred to the continuous paper P or paper S. Specifically, a secondary transfer bias is applied to the secondary transfer roller 424, and a charge having a polarity opposite to that of the toner is applied to the back side of the continuous paper P or the paper S (the side in contact with the secondary transfer roller 424). Thus, the toner image is electrostatically transferred onto the continuous paper P or the paper S. The continuous paper P or paper S to which the toner image is transferred is conveyed toward the fixing unit 60.

  The belt cleaning device 426 removes transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer. Instead of the secondary transfer roller 424, a configuration (so-called belt-type secondary transfer unit) in which a secondary transfer belt is looped around a plurality of support rollers including the secondary transfer roller is adopted. Also good.

  The fixing unit 60 includes an upper fixing unit 60A having a fixing surface side member disposed on the fixing surface (surface on which the toner image is formed) of the continuous paper P or paper S, and the back surface (fixing) of the continuous paper P or paper S. A lower fixing unit 60B having a back side support member disposed on the side opposite to the surface), a heating source 60C, and the like. When the back surface side support member is pressed against the fixing surface side member, a fixing nip for nipping and transporting the continuous paper P or the paper S is formed.

  The fixing unit 60 fixes the toner image on the continuous paper P or the paper S by heating and pressurizing the continuous paper P or the paper S, to which the toner image is secondarily transferred and conveyed, at the fixing nip. The fixing unit 60 is disposed in the fixing device F as a unit. The fixing device F may be provided with an air separation unit that separates the continuous paper P or the paper S from the fixing surface side member or the back surface side support member by blowing air.

  The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, a transport path unit 53, and the like. In the three paper feed tray units 51a to 51c constituting the paper feed unit 51, paper S (standard paper, special paper) identified based on basis weight, size, etc. is stored for each preset type. . The conveyance path unit 53 includes a plurality of conveyance roller pairs such as registration roller pairs 53a.

  The sheets S stored in the sheet feed tray units 51 a to 51 c are sent one by one from the top and are conveyed to the image forming unit 40 by the conveyance path unit 53. At this time, the registration roller portion provided with the registration roller pair 53a corrects the inclination of the fed paper S and adjusts the conveyance timing. In the image forming unit 40, the toner image on the intermediate transfer belt 421 is secondarily transferred onto one side of the sheet S at a time, and a fixing process is performed in the fixing unit 60. Further, the continuous paper P fed from the paper feeding device 1 to the image forming device 2 is conveyed to the image forming unit 40 by the conveyance path unit 53. Then, in the image forming unit 40, the toner image on the intermediate transfer belt 421 is secondarily transferred to one side of the continuous paper P all at once, and a fixing process is performed in the fixing unit 60. The continuous paper P or the paper S on which an image has been formed is discharged out of the apparatus by a paper discharge unit 52 having a paper discharge roller 52a.

  The first slack forming device 3 is installed on the downstream side of the image forming device 2 and on the upstream side of the second slack forming device 4 in the conveyance direction of the continuous paper P. The first slack forming device 3 conveys the continuous paper P conveyed from the image forming device 2 to the second slack forming device 4. The first slack forming device 3 has an image forming speed (corresponding to the conveying speed of the continuous paper P) in the image forming apparatus 2 and a reading speed (corresponding to the conveying speed of the continuous paper P) in the correction inspection image reading unit 84 described later. In order to absorb the difference in the conveyance speed, a slack portion P1 is formed and held on the continuous paper P.

  In the housing of the first slack forming device 3, a first slack amount detecting unit 80, which is a distance sensor, is provided. The first slack amount detection unit 80 determines the distance from the first slack amount detection unit 80 to the bottom surface position P2 of the slack portion P1 of the continuous paper P in the direction of gravity perpendicular to the transport direction of the continuous paper P. Detect as. More specifically, the first slack amount detection unit 80 includes a light emitting unit and a light receiving unit (not shown). The positional relationship between the first slack amount detection unit 80 and the continuous paper P in the housing of the first slack forming device 3 is that the light emitted from the light emitting unit is the upper surface position (lowermost surface position P2) of the slack portion P1 of the continuous paper P. ) And reflected back to the light receiving unit. The first slack amount detection unit 80 determines the distance (from the first slack amount detection unit 80 to the lowermost surface position P2 in the slack portion P1 of the continuous paper P depending on where the reflected light has returned to the light receiving element in the light receiving unit ( First slack amount) is detected. The first slack amount detection unit 80 transmits the detected first slack amount to the control unit 101 of the image forming apparatus 2.

  In addition, a cooling unit 82 is provided above the first slack amount detection unit 80 in the housing of the first slack forming device 3. The cooling unit 82 cools the continuous paper P on which the first slack portion P1 is formed by the first slack forming device 3 by blowing cooling air toward the image forming surface side of the continuous paper P. The air blowing operation of the cooling unit 82 is controlled by the control unit 101 provided in the image forming apparatus 2.

  On the downstream side of the first slack forming device 3 and the upstream side of the second slack forming device 4 in the transport direction of the continuous paper P, the corrected inspection image reading unit 84 and the reading transport unit 86 (the “conveying speed changing unit” of the present invention). Is provided). The corrected inspection image reading unit 84 is a color line sensor, and has a width equal to or larger than the maximum width of the continuous paper P used in the image forming system 100 in a direction (main scanning direction) orthogonal to the conveyance direction of the continuous paper P. The correction inspection image formed on the continuous paper P is read in two dimensions in the main scanning direction and the sub-scanning direction.

  The correction inspection image reading unit 84 includes a plurality of reading elements arranged in a line in a direction orthogonal to the conveyance direction of the continuous paper P, and each reading element reflects reflected light reflected from an image on the continuous paper P. Is output to the control unit 101 of the image forming apparatus 2. The corrected inspection image reading unit 84 is configured by arranging line sensors of red, green, and blue color channels in parallel. The line sensor of the red channel includes a red filter and outputs an output value (R signal) corresponding to the light intensity. The green channel line sensor includes a green filter, and outputs an output value (G signal) corresponding to the intensity of light. The blue channel line sensor includes a blue filter and outputs an output value (B signal) corresponding to the intensity of light.

  The corrected inspection image is, for example, a margin of the continuous paper P by the image forming unit 40 controlled by the control unit 101 every time image forming processing for a length corresponding to 1000 sheets of A4 paper is performed on the continuous paper P. It is formed in a part (both ends). As the correction inspection image, for example, as shown in FIG. 3, a patch image I for color correction (control strip), a reference image T (register mark image) for correcting the deviation of the image position, and inspection of the continuous paper P are used. Examples thereof include a barcode image B for performing.

  As illustrated in FIG. 1, the reading conveyance unit 86 includes two conveyance roller pairs, and conveys the continuous paper P conveyed from the first slack forming device 3 to the second slack forming device 4. The conveyance operation of the reading conveyance unit 86 is controlled by the control unit 101 provided in the image forming apparatus 2. However, when the correction inspection image reading unit 84 reads the corrected inspection image, if the conveyance speed of the reading conveyance unit 86 fluctuates in the middle, the reading error due to the shift of the reading region of the correction inspection image becomes very large. End up. Therefore, in the present embodiment, while the corrected inspection image is read by the corrected inspection image reading unit 84, the control unit 101 sets the reading and conveying unit 86 so that the conveying speed of the continuous paper P is constant. Control.

  The second slack forming device 4 is installed on the downstream side of the correction inspection image reading unit 84 and on the upstream side of the winding device 5 in the conveyance direction of the continuous paper P. The second slack forming device 4 transports the continuous paper P transported from the reading transport unit 86 to the winding device 5. The second slack forming device 4 includes a reading speed (corresponding to the conveying speed of the continuous paper P by the reading and conveying unit 86) in the correction inspection image reading unit 84, and a winding speed (conveying speed of the continuous paper P) in the winding device 5. In order to absorb the difference in the conveyance speed with respect to the continuous paper P, a slack portion P3 is formed and held on the continuous paper P. By providing the second slack forming device 4, the continuous paper P is prevented from being pulled by the winding operation of the winding device 5, and the corrected inspection image reading unit 84 forms the correction inspection formed on the continuous paper P. The image can be read accurately.

  In the housing of the second slack forming device 4, a second slack amount detecting unit 88 that is a distance sensor is provided. The second slack amount detection unit 88 detects the distance from the second slack amount detection unit 88 to the bottom surface position P4 of the slack portion P3 of the continuous paper P as the second slack amount in the gravity direction of the continuous paper P. More specifically, the second slack amount detection unit 88 includes a light emitting unit and a light receiving unit (not shown). The positional relationship between the second sag amount detection unit 88 and the continuous paper P in the housing of the second sag forming device 4 is such that the light emitted from the light emitting unit is the upper surface position (lowermost surface position P4) of the sag portion P3 of the continuous paper P. ) And reflected back to the light receiving unit. The second slack amount detection unit 88 detects the distance (second slack amount) from the second slack amount detection unit 88 to the lowermost surface position P4 depending on where the reflected light has returned to the light receiving element in the light receiving unit. . The second slack amount detection unit 88 transmits the detected second slack amount to the control unit 101 of the image forming apparatus 2.

  The winding device 5 is a device that winds the continuous paper P conveyed from the second slack forming device 4. In the casing of the winding device 5, for example, as shown in FIG. 1, the continuous paper P is wound around a support shaft and held in a roll shape. Therefore, the winding device 5 uses the continuous paper P conveyed from the second slack forming device 4 to the support shaft at a constant speed via a plurality of rollers (for example, a feeding roller and a paper discharge roller). Wind up. The winding operation of the winding device 5 is controlled by the control unit 101 provided in the image forming apparatus 2.

  By the way, the winding speed (corresponding to the conveying speed of the continuous paper P) in the winding device 5 varies depending on the outer diameter of the continuous paper P wound up by the winding device 5, and consequently in the second slack forming device 4. The second slack amount of the continuous paper P varies. Therefore, the control unit 101 performs winding according to the second slack amount detected by the second slack amount detecting unit 88 so that the second slack amount of the continuous paper P in the second slack forming device 4 is as constant as possible. The winding speed of the continuous paper P by the take-up device 5 is controlled. For example, when the outer diameter of the continuous paper P increases, the winding speed in the winding device 5 increases and the second slack amount in the second slack forming device 4 decreases. Reduce the rotation speed.

  The control unit 101 corrects the image forming condition by the image forming unit 40 according to the reading result of the corrected inspection image reading unit 84. For example, the control unit 101 sets the color of an image formed based on the image data to a preferable color (a color having high reproducibility), and the patch image I is read from the result of reading the patch image I by the correction inspection image reading unit 84. The RGB values are calculated, and the image forming conditions by the image forming unit 40 are corrected based on the calculation results (color correction). Further, the control unit 101 obtains the distance between the paper edge portion of the continuous paper P in the main scanning direction and the reference image T according to the reading result of the reference image T by the correction inspection image reading unit 84. Then, the control unit 101 calculates the positional deviation amount of the image in the main scanning direction of the continuous paper P from the obtained distance, and the image forming condition (main scanning condition) by the image forming unit 40 based on the calculated positional deviation amount. (Direction writing direction) is corrected (deviation correction). In addition, the control unit 101 inspects the continuous paper P in accordance with the reading result of the corrected inspection image reading unit 84. Specifically, the control unit 101 detects a defect and a stain of an image formed on the continuous paper P, wrinkles generated on the continuous paper P, and the like.

  FIG. 4 is a flowchart illustrating an example of the conveyance control operation of the image forming system 100 according to the present embodiment. The processing in step S100 starts when a print job is set by the user via the operation unit 22 of the image forming apparatus 2 and the print button is pressed following the setting.

  First, the control unit 101 controls the reading conveyance unit 86 to set the conveyance speed of the continuous paper P to V1 (corresponding to the “second conveyance speed” of the present invention) that is 5% lower than the image forming speed V, for example. (Step S100). Thereby, due to the conveyance speed difference between the image forming apparatus 2 and the reading conveyance unit 86, the first slack amount of the continuous paper P in the first slack forming apparatus 3 increases from L1 (normal slack amount). The control unit 101 causes the image forming unit 40 to form a corrected inspection image so that the corrected inspection image is read by the corrected inspection image reading unit 84 when the conveyance speed of the continuous paper P is V1. .

  Next, the control unit 101 refers to the detection result of the first slack amount detection unit 80, and whether the first slack amount of the continuous paper P has reached L2 (corresponding to the “first predetermined slack amount” of the present invention). It is determined whether or not (step S120). As a result of this determination, when the first slack amount of the continuous paper P does not reach L2 (step S120, NO), the process returns to before step S120.

  On the other hand, when the first slack amount of the continuous paper P has reached L2 (step S120, YES), the control unit 101 controls the reading / conveying unit 86 so that the conveyance speed of the continuous paper P is, for example, 5 from the image forming speed V. [%] It is set to fast V2 (corresponding to the “first transport speed” of the present invention) (step S140). Thereby, due to the conveyance speed difference between the image forming apparatus 2 and the reading conveyance unit 86, the first slack amount of the continuous paper P in the first slack forming apparatus 3 decreases from L2 toward L1. The control unit 101 forms the corrected inspection image in the image forming unit 40 so that the corrected inspection image is read by the corrected inspection image reading unit 84 even when the conveyance speed of the continuous paper P is V2. Let

  Next, the control unit 101 refers to the detection result of the first slack amount detection unit 80, and whether the first slack amount of the continuous paper P has reached L1 (corresponding to the “second predetermined slack amount” of the present invention). It is determined whether or not (step S160). As a result of this determination, when the first slack amount of the continuous paper P does not reach L1 (step S160, NO), the process returns to before step S160. On the other hand, when the first slack amount of the continuous paper P reaches L1 (step S160, YES), the process returns to before step S100.

  In the flowchart of FIG. 4, the control unit 101 has been described with respect to an example in which the correction inspection image is formed in the image forming unit 40 when the conveyance speed of the continuous paper P is V1 or V2. It is not limited to. For example, when the transport speed of the continuous paper P is V1, the reference image T and the barcode image B are formed as the corrected inspection image on the image forming unit 40, while the transport speed of the continuous paper P is V2. The patch image I may be formed in the image forming unit 40 as the corrected inspection image. When the conveyance speed of the continuous paper P is V2, since the reading area of the reference image T and the barcode image B is small, the correction inspection image reading unit 84 may not be able to read the reference image T and the barcode image B accurately. On the other hand, since the reading area of the patch image I is large, there is no possibility that the correction inspection image reading unit 84 cannot read the patch image I accurately.

  Further, only when the conveyance speed of the continuous paper P is V1, the reference image T, the barcode image B, and the patch image I may be formed in the image forming unit 40 as the corrected inspection image. As a result, the reading resolution of the corrected inspection image reading unit 84 in the conveyance direction of the continuous paper P can be increased.

  FIG. 5 is a flowchart showing an example of air blowing control operation of the image forming system 100 according to the present embodiment. The process of step S200 is started at the same timing as the process of step S100 in the flowchart of FIG. That is, the processing in step S200 starts when a user sets a print job via the operation unit 22 of the image forming apparatus 2 and presses the print button following the setting.

  Here, in the air blowing control operation, when a correction inspection image (patch image I) for color correction is formed on the continuous paper P, the correction inspection image is read immediately after the heating process (fixing process). As a result, this is performed in order to reliably prevent the color of the read correction inspection image from being different from the original color. By performing the air blowing control operation, the correction inspection image reading unit 84 can accurately read the color of the correction inspection image.

  First, the control unit 101 controls the cooling unit 82, and sets the cooling air flow rate to F2 (corresponding to the “first air flow rate” of the present invention) (step S200). Next, the control unit 101 refers to the detection result of the first slack amount detection unit 80, and whether or not the first slack amount of the continuous paper P has reached or exceeded Lx (corresponding to the “predetermined slack amount” of the present invention). Is determined (step S220). Here, as shown in FIG. 6, the first slack amount Lx is a slack amount that is larger than the first slack amount L1 described in the flowchart of FIG. 4 and smaller than the first slack amount L2. As a result of this determination, when the first slack amount of the continuous paper P has reached Lx or more (step S220, YES), the control unit 101 controls the cooling unit 82 to reduce the blowing air amount of cooling air to less than F2. Is set to F1 (corresponding to the “second air flow rate” of the present invention) (step S240). Thereafter, the process returns to before step S220.

  When the first slack amount of the continuous paper P reaches Lx or more, the cooling air flow rate is set to F1 for the following reason. That is, as the first slack amount of the continuous paper P increases, the possibility of paper runaway occurring in the continuous paper P increases, so that this paper runaway is prevented in advance. The state of occurrence of paper irregularities is the difference in the thickness of the continuous paper P, the difference between the outside and the inside of the continuous paper P wound around the support shaft of the paper feeding device 1, and the continuous paper P wound around the support shaft. It depends on the amount of curl.

  On the other hand, when the first slack amount of the continuous paper P does not reach Lx or more (step S220, NO), the control unit 101 controls the cooling unit 82 to set the cooling air flow rate to F1 (step S260). ). Thereafter, the process returns to before step S220.

  FIG. 7 is a diagram showing, in time series, the correspondence relationship between the conveyance speed of the continuous paper P, the first slack amount, and the cooling air flow rate until the respective processes in the flowcharts of FIGS.

  In the flowchart of FIG. 5, an example in which the cooling air flow rate is switched in two stages F1 and F2 has been described. However, switching may be performed in three or more stages. In addition, the example in which the possibility of the occurrence of the paper storm has been detected based on the first slack amount of the continuous paper P and the cooling air flow rate is switched has been described. However, the fact that the paper storm has actually occurred has been described. The cooling air flow rate may be switched from F2 to F1 (<F2) by detecting according to the fluctuation of the first slack amount of the continuous paper P in a predetermined time. Since the detection value of the first slack amount changes due to a difference in the conveyance speed between the image forming apparatus 2 and the corrected inspection image reading unit 84, the detection value does not change greatly in a short time. However, if this detected value changes greatly in a short time, it is considered that the paper is actually out of order. FIG. 8 shows that the continuous paper P transport speed, the first slack amount, and the cooling when the air flow of the cooling air is switched by detecting that the paper has actually fluctuated according to the fluctuation of the first slack amount. It is a figure which shows the correspondence of the ventilation volume of a wind in time series. As shown in FIG. 8, the control unit 101 detects that the variation in the first slack amount has occurred, and after switching the cooling air flow rate from F2 to F1, the variation in the first slack amount has subsided. And the cooling air flow rate is switched from F1 to F2.

[Effects of the present embodiment]
As described above in detail, in the present embodiment, the image forming system 100 includes the image forming unit 40 that forms an image on the continuous paper P, and the winding that winds the continuous paper P on which the image is formed by the image forming unit 40. The image capturing device 5, the correction inspection image reading unit 84 having a line sensor that reads the correction inspection image formed on the continuous paper P by the image forming unit 40, and the first slack portion P 1 in the gravity direction are formed on the continuous paper P. The first slack forming device 3 to perform, the first slack amount detection unit 80 for detecting the first slack amount of the first slack portion P1, and the reading conveyance for changing the conveyance speed of the continuous paper P in the image reading unit 84 for correction inspection. Control for controlling the reading and conveying unit 86 so as to change the conveying speed of the continuous paper P in the corrected inspection image reading unit 84 in accordance with the first sag amount detected by the unit 86 and the first sag amount detecting unit 80. Part 101 and Provided.

  According to the present embodiment configured as described above, a slack portion is formed on the continuous paper P by the first slack forming device 3, and thus occurs between the image forming unit 40 and the correction inspection image reading unit 84. Since the conveyance speed difference is absorbed, no deflection or pulling of the continuous paper P due to the conveyance speed difference occurs, and the correction inspection image formed on the continuous paper P in the correction inspection image reading unit 84 is accurately displayed. Can be read. Further, since the continuous paper P that has been subjected to the heating process (fixing process) is naturally cooled while being conveyed by the first slack forming device 3, a correction inspection image for color correction is formed. In addition, the color of the correction inspection image can be prevented from changing, and the correction inspection image reading unit 84 can accurately read the color of the correction inspection image. As described above, the corrected inspection image formed on the continuous paper P can be accurately read, and the correction of the image forming conditions and the inspection of the continuous paper P can be performed with high accuracy.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Image forming apparatus 3 1st slack forming apparatus 4 2nd slack forming apparatus 5 Winding apparatus 10 Image reading part 20 Operation display part 21 Display part 22 Operation part 30 Image processing part 40 Image forming part 50 Paper conveyance part DESCRIPTION OF SYMBOLS 60 Fixing part 71 Communication part 72 Memory | storage part 80 1st slack quantity detection part 82 Cooling part 84 Image reading part for correction inspection 86 Reading conveyance part 88 2nd slack quantity detection part 100 Image forming system 101 Control part 102 CPU
103 ROM
104 RAM
I Patch image T Reference image B Barcode image

Claims (10)

An image forming unit for forming an image on continuous paper;
A take-up unit that is provided on the downstream side of the image forming unit in the conveying direction of the continuous paper and winds up the continuous paper on which an image is formed by the image forming unit;
Corrected inspection having a line sensor that is provided on the downstream side of the image forming unit and the upstream side of the winding unit in the conveyance direction of the continuous paper, and that reads the image for correction inspection formed on the continuous paper by the image forming unit. An image reading unit;
A first slack forming unit provided on the downstream side of the image forming unit in the conveyance direction of the continuous paper and the upstream side of the correction inspection image reading unit, and forming a first slack portion in the gravity direction on the continuous paper;
A first slack amount detection unit for detecting a first slack amount of the first slack portion;
A conveyance speed changing unit that changes a conveyance speed of the continuous paper in the correction inspection image reading unit;
A control unit that controls the transport speed changing unit to change the transport speed of the continuous paper in the correction inspection image reading unit according to the first slack amount detected by the first slack amount detecting unit; ,
An image forming system comprising:   A second slack forming unit is provided on the downstream side of the correction inspection image reading unit and the upstream side of the winding unit in the continuous paper conveyance direction, and forms a second slack portion in the gravity direction on the continuous paper. The image forming system according to claim 1. A second slack amount detection unit for detecting a second slack amount of the second slack portion;
The control unit controls the winding unit so as to change a winding speed of the winding unit according to the second slack amount detected by the second slack amount detection unit. The image forming system according to claim 2.   When the first sag amount detected by the first sag amount detection unit reaches a first predetermined sag amount, the control unit sets a speed at which the continuous paper is transported faster than an image formation speed of the image forming unit. On the other hand, when the first slack amount reaches a second predetermined slack amount that is smaller than the first predetermined slack amount, the second transport speed is controlled to be slower than the image forming speed. The image forming system according to claim 1. The correction inspection image comprises a plurality of types of correction inspection images,
The control unit is configured so that a part of the plurality of types of corrected inspection images is read by the corrected inspection image reading unit when the continuous paper conveyance speed is the first conveyance speed. The correction inspection image is formed on the image forming unit, and when the continuous paper conveyance speed is the second conveyance speed, the correction inspection image reading unit other than the part is corrected by the correction inspection image reading unit. The image forming system according to claim 4, wherein a correction inspection image other than the part is formed in the image forming unit so as to be read.   The control unit reads the corrected inspection image into the image so that the corrected inspection image is read by the corrected inspection image reading unit only when the continuous paper conveyance speed is the second conveyance speed. The image forming system according to claim 4, wherein the image forming system is formed in a forming unit.   2. A cooling unit that cools the continuous paper by blowing cooling air toward the continuous paper on which the first slack portion is formed by the first slack forming unit. 7. The image forming system according to any one of items 6.   The said control part controls the said cooling part so that the ventilation volume of the said cooling air may be changed according to the said 1st slack quantity detected by the said 1st slack quantity detection part. The image forming system described in 1.   The control unit sets the air flow rate of the cooling air to the first air flow rate when the first slack amount detected by the first slack amount detection unit is smaller than a predetermined slack amount, while the first slack amount 9. The image forming system according to claim 8, wherein when the air flow is larger than the predetermined slack amount, the air flow rate of the cooling air is set to a second air flow rate that is smaller than the first air flow rate.   The control unit determines whether or not a paper runaway has occurred in the continuous paper based on a change in the first slack amount detected by the first slackness amount detection unit, and the paper runaway has occurred. When it is determined that there is no air flow, the cooling air flow rate is set to the first air flow rate. On the other hand, when it is determined that the paper turbulence has occurred, the cooling air flow rate is set to be smaller than the first air flow rate. The image forming system according to claim 8, wherein the air blowing amount is set to 2.