Belt conveying device, control method for belt conveying device, and inkjet recording device

Abstract

To provide a belt conveyance device, a control method for the belt conveyance device, and, an inkjet recording device capable of detecting meandering of a conveyance belt without increasing man-hour during assembly or belt replacement.SOLUTION: A belt conveyance device includes: a plurality of edge detection parts that are provided at different positions on a placement surface side of a conveyance belt and detect an edge position of a mark in a width direction perpendicular to a conveyance direction of the conveyance belt; and a drive part that acquires an edge position from the plurality of edge detection parts, and calculates an amount of meandering of the conveyance belt based on the edge position acquired from the plurality of edge detection parts, and controls a drive part based on the amount of meandering.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a belt conveying device, a control method for a belt conveying device, and an inkjet recording device. [Background technology]

[0002] Inkjet recording devices have been used in the past to form (record) images on a recording medium such as paper by ejecting ink from multiple nozzles provided in an inkjet head toward the recording medium. In such inkjet recording devices, a belt conveying device is used as one of the paper conveying means.

[0003] Inkjet recording devices form images by ejecting ink from stationary inkjet heads onto paper transported by a belt transport device, so the accuracy of paper transport directly affects image quality. Therefore, in order to maintain image quality, the belt transport device used in inkjet recording devices performs control to correct meandering of the transport belt that transports the paper.

[0004] In a belt conveying device, meandering correction of the conveyor belt is performed based on the difference between the target position and the current position, so it is necessary to detect the current position of the conveyor belt. Based on the detected current position of the conveyor belt, the steering shaft, which is a conveying mechanism, is controlled to move the conveyor belt's conveying position to the target position, thereby correcting meandering.

[0005] Patent Document 1 discloses a method for controlling meandering correction of a belt drive device, in which the position of the conveyor belt in the conveying direction is identified based on the interval between reference marks provided on the conveyor belt, the positions of the edges of the conveyor belt in the width direction are detected, and the amount of meandering is calculated from the position in the conveying direction and the positions of the edges. Due to manufacturing reasons, the belt edges of conveyor belts are not linear but have some distortion. Therefore, Patent Document 1 measures edge profile data of the conveyor belt in advance, and measures the amount of meandering from the difference between the stored edge profile data and the detected position of the conveyor belt edge. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-272554 Summary of the Invention [Problem to be solved by the invention]

[0007] In this way, in a configuration in which edge profile data of the conveyor belt is measured in advance, it is necessary to acquire the data in advance, which poses a problem of increasing the number of steps required when assembling the conveyor device or replacing the belt.

[0008] Therefore, the present invention aims to provide a belt conveying device, a control method for a belt conveying device, and an inkjet recording device that can detect meandering of a conveying belt without increasing the labor required during assembly or belt replacement. [Means for solving the problem]

[0009] To solve the above problems and achieve the object of the present invention, the belt conveying device of the present invention is an endless conveying belt for conveying a recording medium, the conveying belt having a mark of a predetermined shape formed on an edge of the conveying belt in a width direction perpendicular to the conveying direction on a support surface side on which the recording medium is placed. The belt conveying device also includes a plurality of rollers arranged on the inner periphery of the conveying belt to move the conveying belt in a circular motion, and a drive unit provided at both axial ends of at least one of the plurality of rollers arranged on the inner periphery of the conveying belt and controlling the inclination of the roller by independently moving both ends of the roller. The belt conveying device also includes a plurality of edge detection units arranged at different positions on the support surface side of the conveying belt to detect the edge position of the mark in the width direction perpendicular to the conveying direction of the conveying belt. The belt conveying device also includes a control unit that acquires the edge positions from the plurality of edge detection units, calculates the amount of meandering of the conveying belt based on the edge positions acquired from the plurality of edge detection units, and controls the drive unit based on the amount of meandering.

[0010] The control method for a belt conveying device of the present invention acquires the edge positions of marks in a width direction perpendicular to the conveying direction of the conveying belt from a plurality of edge detection units in the above-mentioned belt conveying device, calculates the amount of meandering of the conveying belt based on the edge positions acquired from the plurality of edge detection units, and controls the drive unit based on the amount of meandering.

[0011] An inkjet recording apparatus of the present invention includes the above-described belt conveying device and an image forming section that forms an image on a recording medium conveyed by the belt conveying device. [Effects of the Invention]

[0012] According to the present invention, meandering of the conveyor belt can be detected without increasing the number of steps required for assembly or belt replacement. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating the configuration of an inkjet recording apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the belt conveying device 30 as viewed from above on the image forming unit 40 side. [Figure 3] 1 is a view of the tension control roller 12 as seen from the direction along the conveyance direction of the recording medium P. FIG. [Figure 4] FIG. 2 is a block diagram showing a drive mechanism 20 in a belt conveying device 30 of the present embodiment, and is a block diagram including a control unit 26. [Figure 5] 4 is a flowchart showing a method for controlling the belt conveyance device 30 according to the embodiment. [Figure 6] This is a table showing the edge positions (upstream measurement positions) detected by the first edge detection unit 25a for each mark M, the edge positions (downstream measurement positions) detected by the second edge detection unit 25b, and the amount of meandering calculated from the difference between them. [Figure 7] 10 is a diagram showing the amount of meandering of the conveyor belt 13 relative to the conveying distance. DETAILED DESCRIPTION OF THE INVENTION

[0014] An example of an inkjet recording apparatus and a method for controlling an inkjet recording apparatus according to an embodiment of the present invention will be described below with reference to the drawings. The inkjet recording apparatus and the method for controlling an inkjet recording apparatus described below include the belt conveying apparatus and the method for controlling a belt conveying apparatus of the present invention. However, the present invention is not limited to the following example. In each of the drawings described below, common components are assigned the same reference numerals.

[0015] 1. Inkjet recording device FIG. 1 is a schematic diagram of an inkjet recording apparatus 1 according to one embodiment of the present invention, as viewed from the side in a direction perpendicular to the conveyance direction of a recording medium P. As shown in FIG. 1, the inkjet recording apparatus 1 includes a belt conveyance device 30 and an image forming unit 40. The inkjet recording apparatus 1 of this embodiment can be used with various print media as the recording medium P, such as paper, fabric, and resin film, on which ink can be fixed when it lands on a sheet-like main surface. The inkjet recording apparatus 1 of this embodiment is configured to use a sheet-like recording medium P.

[0016] The belt conveying device 30 includes a drive roller 11, a driven roller 10, a tension control roller 12, and a conveying belt 13 stretched over these rollers, and rotates the conveying belt 13. As a result, the outer peripheral surface of the conveying belt 13 serves as a loading surface 13a for the recording medium P, and the recording medium P held on this loading surface 13a is conveyed in the direction of rotation of the conveying belt 13. The belt conveying device 30 of this embodiment also includes a drive mechanism 20 related to meandering correction. The detailed configuration of the belt conveying device 30, including the drive mechanism 20, will be described later.

[0017] The image forming unit 40 is composed of an ink supply device 100 disposed between the driven roller 10 and the drive roller 11 at a predetermined distance in a position facing the recording medium P mounting surface 13a, and a paper leading edge position detection sensor 22. The ink supply device 100 has carriages 100K, 100C, 100M, and 100Y, each provided for a different color: black (K), cyan (C), magenta (M), and yellow (Y). The carriages 100K, 100C, 100M, and 100Y are disposed in this order from the upstream side in the conveyance direction of the recording medium P, for example.

[0018] Carriage 100K, 100C, 100M, and 100Y are each configured to extend in a direction perpendicular to the conveyance direction of recording medium P (the width direction of recording medium P), and are set to a width that allows ink to be ejected to a predetermined position on the conveyed recording medium P. In other words, inkjet recording device 1 is a one-pass line head type inkjet recording device. The four carriages 100K, 100C, 100M, and 100Y have the same configuration, except that they eject different colors of ink.

[0019] Each of the carriages 100K, 100C, 100M, and 100Y has an inkjet head (not shown) with nozzles that eject ink. The inkjet head of each of the carriages 100K, 100C, 100M, and 100Y has a plurality of nozzles that eject ink of a color corresponding to the carriage 100K, 100C, 100M, and 100Y. The ink ejected from the nozzles lands on the recording medium P that is being transported.

[0020] The paper leading edge position detection sensor 22 is disposed upstream of the ink supply device 100 in the transport direction of the transport belt 13, and detects the leading edge position of the transported recording medium P. In this embodiment, based on the timing at which the paper leading edge position detection sensor 22 detects the leading edge of the recording medium P, inks of the colors K, C, M, and Y are ejected in order from the carriages 100K, 100C, 100M, and 100Y onto the recording medium P, thereby forming a desired image on the recording medium P.

[0021] 2. Belt conveyor The following describes the detailed configuration of the belt conveying device 30. The belt conveying device 30 is a device for conveying the recording medium P in a predetermined direction. Fig. 2 is a diagram of the belt conveying device 30 as seen from above on the image forming unit 40 side, and Fig. 3 is a diagram of the tension control roller 12 as seen from a direction along the conveying direction of the recording medium P.

[0022] The belt conveying device 30 includes a drive roller 11, a driven roller 10, a tension control roller 12, and an endless conveying belt 13 stretched over these rollers. The belt conveying device 30 further includes a drive mechanism 20 that controls the drive of the tension control roller 12.

[0023] <Drive roller> The drive roller 11 is equipped with a drive motor 14 and rotates freely in a predetermined direction. The drive roller 11 is provided with a rotation speed measurement unit such as a rotary encoder, and the rotation speed measured by this measurement unit is fed back to the drive motor 14, thereby freely controlling the rotation speed.

[0024] <Driven roller> The driven roller 10 is disposed parallel to the driving roller 11, with a distance therebetween that allows the ink supply device 100 to be disposed therebetween. The driven roller 10 is configured to rotate freely, following the rotation of the conveyor belt 13 caused by the rotation of the driving roller 11. A rotary encoder is provided on the driven roller 10, and the rotation speed measured by this rotary encoder is fed back to a control unit (not shown) of the image forming unit 40. This causes ink of each color to be ejected from the ink supply device 100 in synchronization with the conveyance speed of the recording medium P by the belt conveyance device 30, thereby forming a color image on the recording medium P.

[0025] <Tension control roller> The tension control roller 12 is disposed between the drive roller 11 and the driven roller 10 so that its axial direction is substantially parallel to the axial directions of the drive roller 11 and the driven roller 10, and applies pressure to the conveyor belt 13 from the inner circumferential side to the outer circumferential side. The tension control roller 12 is the driven roller 10. In this embodiment, the tension control roller 12 also functions as a steering roller for controlling meandering of the conveyor belt 13. The tension control roller 12 is driven and controlled by a drive mechanism 20, which will be described later, and corrects meandering of the conveyor belt 13.

[0026] <Conveyor belt> The conveyor belt 13 is an endless belt that is stretched around a drive roller 11, a driven roller 10, and a tension control roller 12. The conveyor belt 13 has a plurality of through-holes (not shown) that allow air to pass between its outer and inner circumferential surfaces. These through-holes are provided in a direction (width direction) perpendicular to the conveying direction of the conveyor belt 13, corresponding to the locations where the recording medium P is placed. In the conveyor belt 13, a suction fan (not shown) sucks air from the placement surface 13a of the conveyor belt 13 through the through-holes. As a result, the recording medium P supplied to the placement surface 13a of the conveyor belt 13 is conveyed in the rotational direction of the conveyor belt 13 while being adsorbed to the placement surface 13a. The conveyor belt 13 is made of, for example, steel, but is not limited to this.

[0027] Furthermore, the conveyor belt 13 has a mark M of a predetermined shape on the side of the loading surface 13a on which the recording medium P is placed, at one end side in the direction perpendicular to the transport direction of the recording medium P (width direction), at a position that does not overlap with the position where the recording medium P is placed. In this embodiment, multiple marks M are provided at predetermined intervals. Note that it is sufficient that at least one mark M is provided on the conveyor belt 13, and as in this embodiment, two or more marks M may be provided. When multiple marks M are provided, the interval between consecutive marks M in the transport direction is not particularly specified, and when three or more marks M are provided, the intervals between the marks M may be equal or different. In this embodiment, an example is shown in which three or more marks M are provided at equal intervals, and the interval between adjacent marks M is 100 mm.

[0028] In addition, in this embodiment, the shape of each mark M is a rectangle that is long in the conveying direction of the conveyor belt 13, but is not limited to this. The shape of the mark M may be a circle, an ellipse, or another shape. In addition, the length of the mark M in the conveying direction of the conveyor belt 13 is not particularly limited, but it may be any shape that allows the leading edge position of the mark M to be detected by each of the first mark position detection unit 24a and the second mark position detection unit 24b, which will be described later. In this embodiment, the length of each mark M in the conveying direction of the conveyor belt (mark length) is 10 mm, as an example.

[0029] Furthermore, the mark M only needs to be configured to be detectable by the first mark position detection unit 24a and the second mark position detection unit 24b, or the first edge detection unit 25a and the second edge detection unit 25b, which will be described later, and it is preferable that the mark M be formed in a color opposite (complementary) to the color of the conveying belt 13.

[0030] <Drive mechanism> The drive mechanism 20 includes a drive motor 14 that drives the drive roller 11, a drive unit 21 that drives and controls the tension control roller 12, and a shaft position detection unit 23 (see FIG. 3). As shown in FIGS. 2 and 3, the drive mechanism 20 also includes a first mark position detection unit 24a, a second mark position detection unit 24b, a first edge detection unit 25a, a second edge detection unit 25b, and a control unit 26. Of these, the drive unit 21 and the shaft position detection unit 23 are provided one on each end of the tension control roller 12. As a result, the tension control roller 12 applies pressure from the inner periphery to the outer periphery of the conveyor belt 13 to control the tension of the conveyor belt 13, and also functions as a steering roller that can individually control the positions of both ends.

[0031] The drive motor 14 drives the drive roller 11 to rotate based on a print job input from an external terminal (not shown), for example. The drive motor 14 drives the drive roller 11 to rotate, causing the drive roller 11, the driven roller 10, and the conveyor belt 13, which is wound around the tension control roller 12, to move in a circular motion.

[0032] The drive unit 21 has shafts 21a, 21a that rotatably support both ends of the tension control roller 12, and actuators 21b, 21b for independently moving each of the shafts 21a, 21a in the extension direction. The two shafts 21a, 21a are arranged so that their axial directions are parallel, and extend perpendicular to the axial directions of the drive roller 11 and the driven roller 10. As a result, the drive unit 21 simultaneously moves both ends of the tension control roller 12 in the direction perpendicular to the axial directions of the drive roller 11 and the driven roller 10, thereby controlling the tension applied to the conveyor belt.

[0033] Furthermore, the drive unit 21 moves one end of the tension control roller 12 in a direction perpendicular to the axial direction of the drive roller 11 and the driven roller 10, thereby steering the tension control roller 12. For example, when the conveyor belt 13 meanders, the drive unit 21 pushes down or up one of the two shafts 21a, 21a. This increases the belt tension at one end of the conveyor belt 13 in the width direction, and moves the conveyor belt 13 toward the other end in the width direction of the conveyor belt 13. Therefore, by adjusting the amount by which the drive unit 21 pushes down or up the two shafts 21a, 21a, the amount of meandering of the conveyor belt 13 can be corrected.

[0034] In this embodiment, meandering correction in the driving unit 21 is performed based on values ​​detected by the first and second mark position detecting units 24a and 24b and the first and second edge detecting units 25a and 25b. A control method for meandering correction in the driving unit 21 will be described in detail later.

[0035] The shaft position detectors 23, 23 are used to detect the position of the end of the tension control roller 12, which is moved by the drive unit 21, and the position in the extension direction of each shaft 21a, 21a. The shaft position detectors 23, 23 may be provided, for example, in actuator control units (not shown) provided in the actuators 21b, 21b of each of the two drive units 21, 21. Such shaft position detectors 23, 23 intermittently detect the position of the end of the tension control roller 12 based on the drive positions of the actuators 21b, 21b. The values ​​detected by the shaft position detectors 23, 23 are sent to the control unit 26, which will be described later.

[0036] The first mark position detection unit 24a and the second mark position detection unit 24b are sensors that detect the leading edge of the mark M formed on the conveyor belt 13. Here, the leading edge of the mark M refers to the edge position of the mark M located on the upstream side in the conveying direction of the conveyor belt 13. In other words, the first mark position detection unit 24a and the second mark position detection unit 24b detect the leading edge of the mark M that moves in accordance with the circular movement of the conveyor belt 13.

[0037] The first mark position detector 24a and the second mark position detector 24b are provided at different positions in the transport direction of the conveyor belt 13. In this embodiment, the first mark position detector 24a is provided upstream of the ink supply device 100 in the transport direction of the conveyor belt 13, and the second mark position detector 24b is provided downstream of the ink supply device 100 in the transport direction of the conveyor belt 13. Values ​​detected by the first mark position detector 24a and the second mark position detector 24b are sent to a control unit 26, which will be described later.

[0038] The first edge detection unit 25a and the second edge detection unit 25b are sensors that detect the edge positions of the mark M formed on the conveyor belt 13, that is, the edge positions of the mark M extending in the direction along the conveyance direction of the conveyor belt 13. That is, the first edge detection unit 25a and the second edge detection unit 25b detect the edge positions of the mark M in the width direction perpendicular to the conveyance direction of the conveyor belt 13. In this embodiment, of the contour line (edge ​​shape) constituting the mark M formed on the conveyor belt 13, the edge position on the side opposite to the side on which the recording medium P is placed in the width direction of the conveyor belt 13 is detected.

[0039] Furthermore, the first edge detection unit 25a is provided near the first mark position detection unit 24a, and the second edge detection unit 25b is provided near the second mark position detection unit 24b. In this embodiment, the control unit 26 acquires from the first edge detection unit 25a the edge position detected at the timing when the first mark position detection unit 24a detects the leading edge position of the mark M. Furthermore, the control unit 26 acquires from the second edge detection unit 25b the edge position detected at the timing when the second mark position detection unit 24b detects the leading edge position of the mark M.

[0040] The interval between the first mark position detection unit 24a and the first edge detection unit 25a and the second mark position detection unit 24b and the second edge detection unit 25b is preferably shorter than the length in the transport direction of the transported recording medium P. This makes it possible to detect the amount of meandering at a pitch shorter than the length in the transport direction of the recording medium P, thereby improving the transport accuracy of the recording medium P.

[0041] Information (detection values) on the edge positions detected by the first edge detection unit 25a and the second edge detection unit 25b is sent to the control unit 26 as needed.

[0042] The control unit 26 is connected to the drive units 21, 21, the shaft position detection units 23, 23, the first and second mark position detection units 24a, 24b, and the first and second edge detection units 25a, 25b, and controls each unit. Figure 4 is a block diagram showing the drive mechanism 20 in the belt conveying device 30 of this embodiment, and is a block diagram including the control unit 26.

[0043] As shown in FIG. 4, the control unit 26 includes an input / output control unit 27, a storage unit 28, and a set value extraction unit 29.

[0044] The input / output control unit 27 is connected to the drive motor 14, the drive unit 21, the shaft position detection units 23, 23, the first and second mark position detection units 24a, 24b, the first and second edge detection units 25a, 25b, the memory unit 28, and the setting value extraction unit 29.

[0045] The input / output control unit 27 calculates the amount of meandering of the conveyor belt 13 using the values ​​detected by the first mark position detection unit 24a, the second mark position detection unit 24b, the first edge detection unit 25a, and the second edge detection unit 25b. The input / output control unit 27 then controls the drive of the drive unit 21 based on the calculated amount of meandering, a set value extracted from the data stored in the memory unit 28, and the values ​​detected by the shaft position detection units 23, 23. The input / output control unit 27 also controls the drive of the drive motor 14 based on a print job input from an external terminal (not shown). Note that this embodiment is characterized by a method for calculating the amount of meandering of the conveyor belt 13, which is implemented by the input / output control unit 27. The method for calculating the amount of meandering of the conveyor belt 13 and the control method for meander correction, which are implemented by the input / output control unit 27, will be described later.

[0046] The input / output control unit 27 is hardware used as a computer and is configured by a calculator. Although not shown, the calculator includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The calculator may also include a non-volatile storage and a network interface.

[0047] One of the controls performed by the input / output control unit 27 is a characteristic control that will be described in detail later in the control method for the belt conveying device 30. The control procedure for the belt conveying device 30 is a control program for controlling the operation of each part of the belt conveying device 30, which is a program stored in a ROM or a program loaded from an external device into a RAM or non-volatile storage. This control program causes a computer to execute the steps that will be described later in the control method for the belt conveying device 30.

[0048] The storage unit 28 is a ROM or RAM that stores setting values ​​of the drivers 21, 21 associated with the amount of meandering of the conveyor belt 13. That is, the storage unit 28 stores setting values ​​of the drivers 21, 21 for performing meandering correction.

[0049] Under the control of the input / output control unit 27, the set value extraction unit 29 compares the amount of meandering calculated by the input / output control unit 27 with data related to set values ​​for meandering correction stored in the storage unit 28, and extracts target set values ​​for the drive units 21, 21. The extracted set values ​​are transmitted from the set value extraction unit 29 to the input / output control unit 27. Therefore, the input / output control unit 27 controls the drive of the drive units 21, 21 based on the set values ​​transmitted from the set value extraction unit 29.

[0050] 3. Belt conveyor control method Fig. 5 is a flowchart showing a control method for the belt conveying device 30 according to this embodiment. The control method for the belt conveying device 30 shown in the flowchart in Fig. 5 is a control method for the belt conveying device 30 that is executed by the control unit 26 of the drive mechanism 20 described above, and is particularly a control method related to meandering correction of the conveying belt 13. Below, the procedure of the control method for the belt conveying device 30 will be described with reference to the flowchart in Fig. 5. Note that the process shown in the flowchart in Fig. 5 is started, for example, when the power supply of the belt conveying device 30 or the power supply of the inkjet recording apparatus 1 including the belt conveying device 30 is turned on as a trigger.

[0051] First, the input / output control unit 27 determines whether or not the first mark position detection unit 24a has detected the tip of the predetermined mark M (step S1). If the input / output control unit 27 determines that the first mark position detection unit 24a has not detected the tip of the predetermined mark M, the process ends.

[0052] On the other hand, if the determination in step S1 is "YES," that is, if the input / output control unit 27 determines that the first mark position detection unit 24a has detected the leading edge of the mark, the process proceeds to step S2. In step S2, the input / output control unit 27 acquires the edge position detected by the first edge detection unit 25a at the timing when the first mark position detection unit 24a detected the leading edge of the mark.

[0053] Next, the input / output control unit 27 determines whether the second mark position detection unit 24b has detected the tip of the mark M (step S3). If the input / output control unit 27 determines that the second mark position detection unit 24b has not detected the predetermined mark M, the process ends.

[0054] On the other hand, if the determination in step S3 is "YES," that is, if the input / output control unit 27 determines that the second mark position detection unit 24b has detected the tip of mark M, the process proceeds to step S4. In step S4, the input / output control unit 27 acquires the edge position detected by the second edge detection unit 25b at the timing when the second mark position detection unit 24b detected the tip of mark M.

[0055] Next, the input / output control unit 27 calculates the difference between the edge position of the mark M detected by the first edge detection unit 25a and the edge position of the mark M detected by the second edge detection unit 25b, and calculates the amount of meandering of the conveyor belt 13. Incidentally, when a plurality of marks M are provided on the conveyor belt 13 as in this embodiment, the input / output control unit 27 calculates the difference between the value detected by the first edge detection unit 25a and the value detected by the second edge detection unit 25b for each mark M. That is, the first edge detection unit 25a and the second edge detection unit 25b measure the edge positions at the same location of the same mark M, and the amount of meandering is calculated from the difference.

[0056] FIG. 6 is a table showing the edge positions (upstream measurement positions) detected for each mark M by the first edge detection unit 25a, the edge positions (downstream measurement positions) detected by the second edge detection unit 25b, and the meandering amount calculated from the difference between them. In this embodiment, the meandering amount is calculated when the width of the conveyor belt 13 in the conveying direction is 10 mm and the spacing between adjacent marks M in the conveying direction is 100 mm. Also, FIG. 6 shows the conveying distance of the second and subsequent marks M, with the conveying distance from the first mark M detected by the first mark position detection unit 24a to the position detected by the second mark position detection unit 24b being set as the reference (zero). Also, FIG. 7 is a diagram showing the meandering amount versus the conveying distance of the conveyor belt 13.

[0057] 6, the difference between the edge position (upstream measurement value) detected by the first edge detection unit 25a and the edge position (downstream measurement value) detected by the second edge detection unit 25b based on the first mark M is 1 mm, and the meandering amount is 1 mm. Furthermore, the difference between the edge position (upstream measurement value) detected by the first edge detection unit 25a and the edge position (downstream measurement value) detected by the second edge detection unit 25b based on the second mark M is 1 mm, and the meandering amount is 2 mm. Furthermore, the difference between the edge position (upstream measurement value) detected by the first edge detection unit 25a and the edge position (downstream measurement value) detected by the second edge detection unit 25b based on the third mark M is 0, and in this case, the meandering amount is 2 mm, the same as the meandering amount detected based on the tip position of the second mark M. Furthermore, the difference between the edge position (upstream measurement value) detected by the first edge detection unit 25a based on the fourth mark M and the edge position (downstream measurement value) detected by the second edge detection unit 25b is -1 mm, and in this case the amount of meandering is 1 mm.

[0058] The input / output control unit 27 extracts the meandering amount of the conveyor belt 13 for each mark M as shown in FIG.

[0059] Next, the set value extraction unit 29 compares the meandering amount of the conveyor belt 13 acquired from the input / output control unit 27 with the data stored in the memory unit 28, and extracts a correction value for the drive units 21, 21 according to the meandering amount (step S6). The memory unit 28 stores data related to the correction values ​​for the drive units 21, 21 calculated according to the meandering amount. The correction values ​​for the drive units 21, 21 are correction values ​​related to the movement amounts of the respective shafts 21a, 21b.

[0060] Next, the input / output control unit 27 controls the driving of the driving units 21, 21 based on the setting values ​​of the driving units 21, 21 extracted by the setting value extraction unit 29 (step S7). As a result, the driving units 21, 21 control the driving of one of the two actuators 21b, 21b provided on the edge of the tension control roller 12 based on the amount of meandering of the conveyor belt 13, thereby pushing up or pulling back the shaft. This adjusts the inclination of the tension control roller 12 in the axial direction, and corrects the meandering of the conveyor belt 13.

[0061] In this manner, in this embodiment, meandering of the conveyor belt 13 is corrected.

[0062] In step S2, the input / output control unit 27 may acquire only one edge position detected by the first edge detection unit 25a at the timing when the first mark position detection unit 24a detects the leading edge of the mark, or may acquire edge positions at multiple locations on the mark M and use the average value of these as the edge position. In this case, the input / output control unit 27 acquires edge positions of the edge portion of the mark M extending in the conveying direction of the conveyor belt 13 across multiple locations from the edge information of the mark M detected by the first edge detection unit 25a. Then, the input / output control unit 27 calculates the average value of the edge positions acquired across multiple locations, and uses this average value (average edge position) to calculate the amount of meandering.

[0063] For example, if the shape of the mark M is elliptical or circular, the edge position in the width direction of the conveyor belt 13 will differ depending on the conveyance direction of the conveyor belt 13. In this case, if the edge position is acquired at only one location, the edge position will vary significantly depending on the acquisition timing, which may result in reduced measurement accuracy. In contrast, the edge positions of the mark M detected by the first edge detection unit 25a can be acquired at multiple locations along the conveyance direction, and the average value of these edge positions is used to calculate the amount of meandering of the mark M, thereby improving measurement accuracy. The same applies to step S4.

[0064] In addition, in step S6, the correction value for the driving units 21, 21 is extracted using the meandering amount calculated for each mark M, but the meandering amounts for multiple marks M may be accumulated and the correction value may be extracted based on the accumulated value. In this case, the driving units 21, 21 are controlled using a correction value based on the accumulated value of the meandering amounts at the respective positions of the multiple marks M.

[0065] Although meandering correction is performed by adjusting the axial tilt of the tension control roller 12 using the drive units 21, 21, there is a time lag between adjusting the axial tilt of the tension control roller 12 and actually correcting the meandering of the conveyor belt 13. Therefore, more appropriate meandering correction can be performed by appropriately changing the timing of meandering correction and the interval at which meandering correction is performed after the amount of meandering is detected.

[0066] In this embodiment, the setting values ​​of the drivers 21 are extracted in accordance with the amount of meandering. However, in reality, the setting values ​​of the drivers 21 are determined taking into consideration the value detected by a pressure detector (not shown) that detects the pressure of the conveyor belt 13 and the value detected by the shaft position detectors 23. This embodiment is characterized in that the amount of meandering is calculated from the difference between the values ​​detected by the first edge detector 25a and the second edge detector 25b, and the setting values ​​of the drivers 21 are changed based on the amount of meandering. Therefore, a description of the relationship between the values ​​detected by the pressure detector and the shaft position detectors 23 and the correction values ​​of the drivers 21 when correcting meandering is omitted here.

[0067] According to this embodiment, a mark M is formed on the conveyor belt 13, and the edge position of the mark M is detected by the first edge detection unit 25a and the second edge detection unit 25b, thereby calculating the amount of meandering. Due to manufacturing reasons, the belt edge of a conveyor belt is not straight. Therefore, as in the past, when measuring the amount of meandering at the edge of the conveyor belt, it was necessary to create a profile of the conveyor belt in advance. In contrast, in this embodiment, the amount of meandering can be detected without detecting the edge position of the conveyor belt 13 itself. This eliminates the need to create a profile of the conveyor belt, thereby reducing the number of steps required during assembly and belt replacement.

[0068] The above-described embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to a configuration including all of the described components. For example, the above-described embodiment uses the first and second edge detection units 25a and 25b, but two or more edge detection units may be used, and the amount of meandering may be calculated using the difference between the edge positions detected by these edge detection units. Furthermore, it is possible to replace part of the configuration of the embodiment with another configuration, or to add another configuration to the configuration of the embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of the embodiment with another configuration. [Explanation of symbols]

[0069] 1...inkjet recording device, 10...driven roller, 11...driving roller, 12...tension control roller, 13...conveyor belt, 13a...mounting surface, 14...driving motor, 20...driving mechanism, 21...driving unit, 21a...shaft, 21b...actuator, 22...paper leading edge position detection sensor, 23...shaft position detection unit, 24a...first mark position detection unit, 24b...second mark position detection unit, 25a...first edge detection unit, 25b...second edge detection unit, 26...control unit, 27...input / output control unit, 28...storage unit, 29...setting value extraction unit, 30...belt conveying device, 30...conveyor belt, 40...image forming unit, 100...ink supply device

Claims

1. an endless conveyor belt for conveying a recording medium, the conveyor belt having a mark of a predetermined shape formed on an end portion in a width direction perpendicular to the conveying direction on a loading surface side on which the recording medium is loaded; a plurality of rollers disposed on an inner peripheral surface side of the conveyor belt to move the conveyor belt in a circular motion; a driving unit provided at both ends in an axial direction of at least one of the plurality of rollers, the driving unit controlling the inclination of the roller by independently moving both ends of the roller; a plurality of edge detection units provided at positions facing the placement surface of the conveyor belt and configured to detect edge positions of the marks; a control unit that calculates the amount of meandering of the conveyor belt based on the edge positions acquired from the plurality of edge detection units and controls the drive unit; Equipped with The meandering amount is calculated based on the difference between the edge positions detected by the plurality of edge detection units. Belt conveyor.

2. The meandering amount is calculated by accumulating the differences between the edge positions detected by the plurality of edge detection units. The belt conveying device according to claim 1 .

3. a mark position detection unit that detects a leading edge of the mark in a conveying direction of the conveyor belt is provided near each of the plurality of edge detection units; The control unit acquires from the edge detection unit the edge position detected at the timing when the mark position detection unit provided near the edge detection unit detects the leading edge of the mark. The belt conveying device according to claim 1 .

4. The interval between the plurality of edge detection units is shorter than the length of the conveyed recording medium in the conveying direction. The belt conveying device according to claim 1 .

5. a plurality of marks are provided in the conveying direction of the conveyor belt, The control unit calculates the amount of meandering from the difference in edge positions of the same mark detected by the plurality of edge detection units. The belt conveying device according to claim 1 .

6. The control unit acquires edge positions of the mark at a plurality of locations along the conveyance direction of the conveyor belt from the detection values ​​detected by the edge detection unit, calculates an average value of the edge positions acquired at the plurality of locations, and calculates the amount of meandering based on the average value. The belt conveying device according to claim 1 .

7. The plurality of rollers a drive roller disposed on the inner periphery of the conveyor belt and driving the conveyor belt; a tension control roller disposed on an inner periphery of the conveyor belt and configured to adjust the tension of the conveyor belt; The drive units are provided at both axial ends of the tension control roller. The belt conveying device according to claim 1 .

8. an endless conveyor belt for conveying a recording medium, the conveyor belt having a mark of a predetermined shape formed on an end portion in a width direction perpendicular to the conveying direction on a loading surface side on which the recording medium is loaded; a plurality of rollers disposed on an inner periphery of the conveyor belt to move the conveyor belt in a circular motion; a driving unit provided at both ends in an axial direction of at least one of the plurality of rollers, the driving unit controlling the inclination of the roller by independently moving both ends of the roller; a plurality of edge detection units that detect edge positions of the mark in a width direction perpendicular to a conveying direction of the conveyor belt, acquiring the edge positions from the plurality of edge detection units, calculating the amount of meandering of the conveyor belt based on the edge positions, and controlling the driving unit; The meandering amount is calculated based on the difference between the edge positions detected by the plurality of edge detection units. A method for controlling a belt conveying device.

9. an endless conveyor belt for conveying a recording medium, the conveyor belt having a mark of a predetermined shape formed on an end portion in a width direction perpendicular to the conveying direction on a loading surface side on which the recording medium is loaded; a plurality of rollers disposed on the inner peripheral side of the conveyor belt and moving the conveyor belt in a circular motion; a drive unit provided at both axial ends of at least one of the plurality of rollers and controlling the inclination of the roller by moving both ends of the roller independently; a plurality of edge detection units provided at a position facing the loading surface of the conveyor belt and detecting the edge positions of the marks; and a control unit that calculates the amount of meandering of the conveyor belt based on the edge positions acquired from the plurality of edge detection units and controls the drive of the drive unit. a belt conveying device comprising: an image forming unit that forms an image on the recording medium conveyed by the belt conveying device; Equipped with The meandering amount is calculated based on the difference between the edge positions detected by the plurality of edge detection units. Inkjet recording device.

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