JP5944332B2 - Medium conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a medium conveying apparatus, an image forming apparatus, and a medium conveying method, and more particularly to a medium conveying technique for grasping and conveying a leading edge of a sheet medium.

  An ink jet printing system using water-based ink includes a drying process for removing excess moisture on the paper after the printing process, and a fixing process for fixing the ink on the paper. 2. Description of the Related Art A chain gripper that grips and conveys the leading edge of a sheet by a gripper connected to two endless chains is known as a conveying unit that conveys the sheet in a drying process and a fixing process.

  Patent Document 1 describes a chain gripper provided with a guide member that sucks and holds the back side of a sheet of paper.

  Patent Document 2 describes a configuration including a paper guide that sucks the back surface of a sheet in transfer cylinder conveyance in which a sheet is conveyed by gripping the leading edge of the sheet with a gripper.

  Patent Document 3 describes a configuration in which a suction mechanism (opening groove) having a long hole shape is provided in a transport mechanism that transports while holding the back surface of a film (sheet).

JP 2008-7243 A JP 2009-285877 A JP-A-1-256442

  However, since the paper is not fixed in the paper transport using the chain gripper, if the moisture on the paper is evaporated by the drying process, the paper will be deformed (wrinkles, curls, cockles) and the quality as a printed matter There is a problem that decreases.

  With the configuration described in Patent Document 1 and the configuration described in Patent Document 2, there is a concern about deformation of the paper due to occurrence of sagging or uneven fixing in a portion where the paper is not attracted.

  According to the configuration described in Patent Document 3, if the paper is dried and applied to the drying process, deformation due to uneven drying of the paper can be suppressed to some extent, but there is slack in the state of being supported (fixed) first. If there is, there is a concern about deformation of the paper due to the slack.

  SUMMARY An advantage of some aspects of the invention is that it provides a medium conveying apparatus, an image forming apparatus, and a medium conveying method capable of preventing deformation of a medium in a conveying form in which a front end of a medium is gripped and conveyed. Objective.

  In order to achieve the above object, a medium conveying apparatus according to the present invention grips a tip-side fixed portion downstream from the center in the medium conveying direction in a medium conveying apparatus that conveys in a sheet conveying direction. A plurality of fixing portions each having a first fixing means, a moving means for moving the first fixing means along the conveying direction, and a medium fixing surface arranged at a predetermined interval below the first fixing means. The length of the fixed area on the medium fixing surface in the transport direction is less than a quarter of the total length in the transport direction of the smallest medium used in the medium transport device. A second fixing means that has a structure and fixes the rear end side fixed portion upstream from the center in the conveyance direction of the medium to be conveyed, and the position of the upstream end in the conveyance direction of the medium to be conveyed. To multiple fixed parts Includes a fixed control means for switching sequentially to the downstream side, the fixing and release of the fixed from the upstream side in the transport direction that.

  According to the present invention, when gripping and transporting the front-end-side fixed portion of the sheet medium, the rear-end-side fixed portion upstream from the center in the medium transport direction is Fixed to the medium holding surface below the fixed position, and the fixed and release of the rear end fixed part is switched according to the position of the upstream end of the medium to be conveyed. The medium is prevented from being steep and the medium is prevented from being deformed during conveyance.

  Further, by fixing the fixed portion on the rear end side of the medium, tension in the direction opposite to the transport direction can be applied to the medium to be transported, and deformation of the medium during transport is prevented.

The block diagram which shows the whole structure of the conveying apparatus which concerns on embodiment of this invention. FIG. 1 is a plan view of the transfer device shown in FIG. Block diagram schematically showing the configuration of the transport guide The block diagram which shows schematic structure of the control system of the conveying apparatus shown in FIG. FIG. 1 is an explanatory diagram of medium adsorption of the conveyance device shown in FIG. 1, (a) an explanatory diagram schematically illustrating a state before adsorption switching, and (b): an explanatory diagram schematically illustrating a state after adsorption switching. Explanatory drawing of the modification of a conveyance guide, (a): Plan view of a conveyance guide, (b): Perspective side view which shows the three-dimensional structure of a conveyance guide Explanatory drawing of other modified examples of the transport guide Explanatory drawing of other modes of transport guide Explanatory drawing of the other aspect of the conveyance guide shown in FIG. FIG. 8 is an explanatory view of the suction switching control of the conveyance guide, (a) an explanatory view schematically showing a state before the suction switching, and (b): an explanatory view schematically showing a state after the suction switching. Overall configuration diagram of a transport apparatus including a transport guide having another configuration 1 is an overall configuration diagram of an ink jet recording apparatus to which a conveyance device according to an embodiment of the present invention is applied. The block diagram which shows schematic structure of the control system of the inkjet recording device shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

〔overall structure〕
FIG. 1 is an overall configuration diagram showing a schematic configuration of a medium conveyance device (hereinafter referred to as a conveyance device) according to an embodiment of the present invention.

  The conveying device 10 shown in the figure has a pair of endless chains 14 on the first sprocket 12A and the second sprocket 12B (in FIG. 1, only one side (one) of the pair (two) chains is shown). Is wound around (moving means).

  A gripper 16 (first fixing means) is attached to the chain 14 at regular intervals in a direction parallel to the conveying direction of the sheet medium 18 (the moving direction of the chain 14, illustrated by the arrow line).

  Note that “parallel” in the present specification may include an error to the extent that substantially the same effect as that of parallelism can be obtained.

  The medium 18 that grips (fixes) the distal-side fixed portion 18A by the gripper 16 curves downward from the distal-side fixed portion 18A and hangs down. The medium 18 is disposed below the gripper 16 in a state of being inclined downward from the downstream side to the upstream side in the conveyance direction of the medium 18, and is disposed at a constant interval with the gripper 16. The rear end side fixed portion 18B is sucked and held (fixed) on the medium fixing surface 20A of the conveyance guide 20 (second fixing means) and conveyed in the direction indicated by the arrow line in FIG.

  The transport guide 20 is partitioned (divided) into a plurality of regions (shown with reference numeral 20B) along the transport direction of the medium 18. That is, the conveyance guide 20 has a structure in which a plurality of suction portions 20B are arranged at predetermined intervals along the conveyance direction of the medium 18.

  Although details will be described later, the conveyance guide 20 is configured to be able to switch on / off of the suction individually for each suction portion 20B (fixed portion).

  As shown in FIG. 1, the medium 18 has a front end side fixed portion 18 </ b> A gripped in the processing area of the processing apparatus 22, and the rear surface (surface on the conveyance guide 20 side) of the rear end side fixed portion 18 </ b> B of the medium 18. ) Is sucked and held, so that it is conveyed without sagging.

  Here, the “fixed portion 18A on the leading end side of the medium 18” means the tip 18C side (on the downstream side in the transport direction of the medium 18) from the center in the transport direction of the medium 18 (shown with reference numeral 18E in FIG. 2). The end side) and means a portion gripped by the gripper 16. Further, the “rear end side fixed portion 18 </ b> B” of the medium 18 is the rear end 18 </ b> D side (end side upstream in the transport direction of the medium 18) from the center of the medium 18, and the back surface is adsorbed by the transport guide 20. Means the part.

  The processing device 22 illustrated in FIG. 1 includes a drying processing device that performs a drying process on a medium 18 on which an image (pattern) is formed by an inkjet method, a fixing processing device that fixes an image and a pattern formed on the medium 18, and the like. Various processing apparatuses can be applied. An embodiment including a plurality of processing devices is also possible.

  The processing device 22 in the following description is a drying processing device that performs a drying process on a medium 18 on which an image is formed by an inkjet method, and a fixing processing device that performs a fixing process.

  As an example of the configuration of the drying treatment apparatus, an aspect including heating means such as a heater and air blowing means such as a blower can be cited. Further, examples of the configuration of the fixing processing apparatus include an aspect provided with a heating means such as a heater, a pressing means such as a pressure roller, and an aspect provided with a light source that emits actinic rays such as ultraviolet rays.

  FIG. 2 is a view of the transfer device 10 shown in FIG. 1 as viewed from above. A base frame 16A is connected to the chain 14 shown in the figure via a connecting member 14A. The base frame 16 </ b> A is stretched between the two chains 14 and is fixed orthogonally (crossing) to the two chains 14.

  Note that the term “orthogonal” in this specification may include an error that can obtain substantially the same effect as orthogonal.

  In FIG. 2, only one set of the connecting member 14A and the base frame 16A is shown, but the set of the connecting member 14A and the base frame 16A is arranged on the chain 14 in a direction parallel to the conveyance direction of the medium 18 (shown by the arrow line). Attached at predetermined intervals along.

  The arrangement interval between the connecting member 14A and the base frame 16A corresponds to the entire length along the conveyance direction of the medium 18 to be used.

  In the base frame 16A, a plurality of grippers 16 are preliminarily provided along a width direction (longitudinal direction of the base frame 16A, shown by a double arrow line) perpendicular to the conveying direction of the medium 18 (shown by a broken line in FIG. 2). Arranged at predetermined intervals. The arrangement interval of the grippers 16 corresponds to the entire width of the medium 18 to be used (the total length in the direction orthogonal to the conveyance direction of the medium 18).

  A plurality of suction holes 20 </ b> C are formed in the medium fixing surface 20 </ b> A of the transport guide 20. The suction hole 20 </ b> C communicates with a chamber (not shown) inside the conveyance guide 20. By setting the inside of the chamber to a negative pressure (vacuum), an adsorption pressure is generated in each of the plurality of adsorption holes 20C.

  The area where the suction holes 20C are arranged on the medium fixing surface 20A (the suction pressure generation area 20D shown in FIG. 3) corresponds to the size of the medium to be used. FIG. 2 illustrates an aspect in which the suction holes 20 </ b> C are arranged at equal intervals in each of the conveyance direction of the medium 18 and the width direction of the medium 18.

  In addition, the arrangement | positioning space | interval of 20 C of suction holes is not limited to the aspect illustrated in FIG. For example, a staggered arrangement, a radial arrangement, a concentric arrangement, and the like can be applied.

  As described above, the transport guide 20 has a plurality of suction units 20B arranged in the transport direction of the medium 18, and can switch on / off of suction for each suction unit 20B. That is, the suction is sequentially switched from the suction unit 20B on the upstream side in the transport direction of the medium 18 to the suction unit 20B on the downstream side in correspondence with the position of the rear end 18D of the medium 18 that is moved by the transport of the medium 18 (details will be described later). .

  FIG. 3 is a block diagram schematically illustrating the configuration of the conveyance guide 20. As shown in the figure, one end of a flow path (a tributary) 30 is connected to each adsorption portion 20 </ b> B of the conveyance guide 20. A valve 32 is attached to each flow path 30 and the other end is connected to a flow path (main flow) 34. Further, the flow path (main flow) 34 is a means for generating negative pressure (vacuum) (adsorption pressure generation). And a pump 36 (pressure generating means) functioning as a means.

  The valve 32 is an electromagnetic control valve that is switched on and off by a control (command) signal. That is, the rear end of the medium 18 is always switched by switching on and off the valves 32 corresponding to the respective suction portions 20B of the transport guide 20 corresponding to the position of the rear end fixed portion 18B of the medium 18 (see FIG. 2). Only the side fixed portion 18 </ b> B can be sucked and held (fixed) on the medium fixing surface 20 </ b> A of the conveyance guide 20.

  A region surrounded by a dashed line in FIG. 3 is an adsorption pressure generation region 20D (fixed region) in the adsorption unit 20B of the conveyance guide 20. The suction pressure generation region 20D is a region where the suction holes 20C are disposed, and is a region where the back side of the medium 18 can actually be sucked.

  The total length L in the medium conveyance direction of the adsorption pressure generation region 20D is less than a quarter of the total length in the same direction of the minimum size medium 18 used in the conveyance device 10.

  The maximum value (upper limit) of the total length L in the medium conveyance direction of the adsorption pressure generation region 20D is determined from the viewpoint of adsorbing the upstream side in the same direction from the central position of the medium 18 in the same direction.

That is, for two adjacent suction unit 20B, since both may be adsorbed media 18 simultaneously (described in detail later), and the total length L ₁ of the medium conveying direction of the suction pressure generating region 20D of one of the suction unit 20B, The sum (L ₁ + L ₂ + L ₃ ) of the total length L _{2 in} the same direction of the suction pressure generation region 20 D of the other suction portion 20 B and the total length L _{3 in} the same direction of the region between them is the same direction of the medium 18. It is determined in less than 1/2 of the overall length _{L 4} and _{(L 1 + L 2 + L} 3 <L 4/2).

Therefore, when L ₃ << L ₁ , L ₃ << L ₂ , and L ₁ = L ₂ , L ₁ <L _4/4 and L ₂ <L _4/4 . _{Incidentally, L 3} «L _1, L ₃ cover the «L ₂ a long if _L 3 = 0, 1/4 of the same direction of the overall length _{L 4} of the full length _{L 11} of the medium 18 in the medium transport direction of the suction part 20B less than _{(L 11 <L 4/4} ) may be.

  Further, the arrangement interval of the adsorption pressure generation region 20D in the medium conveyance direction is the same as the length of the adsorption pressure generation region 20D in the same direction.

  The minimum value (lower limit) of the length L in the same direction in which the medium 18 is attracted to the transport guide 20 is the diameter of the suction hole 20C.

  That is, the minimum value of the total length L in the medium conveyance direction of the adsorption pressure generation region 20D is determined from the viewpoint that the medium 18 is reliably adsorbed. Since this value depends on the thickness and properties (rigidity, etc.) of the medium 18, it is determined based on an actual measurement value obtained by actually measuring the medium to be used.

  In this example, the mode in which a group of suction holes is provided in the suction pressure generation region 20D is a case where the total length L in the medium transport direction of the suction pressure generation region 20D is the minimum value, and the suction pressure generation region 20D at this time The total length L in the medium conveyance direction is the diameter of the suction hole 20C.

  In this aspect, the diameter of the suction holes 20C, the arrangement interval of the suction holes 20C, and the generated pressure (operating conditions) of the pump 36 are determined so that the suction pressure necessary for the suction of the medium 18 is generated from a group of suction holes. ing.

  As the conveyance of the medium 18 progresses, the adsorption pressure acting on the medium 18 decreases and the adsorption of the medium becomes unstable as the length in the same direction in which the medium 18 is adsorbed to the conveyance guide 20 (area to be adsorbed) decreases. There is a concern to become. Therefore, by increasing the pressure generated by the pump 36 as the portion to be adsorbed of the medium 18 becomes smaller, it is possible to prevent the adsorption of the medium 18 from becoming unstable.

  That is, the transport apparatus 10 shown in this example is located on the rear surface (medium fixing surface) on the rear side near the rear end of the medium 18 on the upstream side (rear side) with respect to the center 18E in the transport direction of the medium 18. The medium 18 is transported in a state where it is adsorbed from the side of the surface 20A in contact with 20A and the tip side fixed portion 18A of the medium 18 is gripped by the gripper 16.

  Then, the front end fixed portion 18A of the medium 18 to the rear end fixed portion 18B are fixed with a gentle gradient, the steep gradient at the front end fixed portion 18A of the medium 18 is eliminated, and the medium 18 is transported. Occurrence of wrinkles and sagging is prevented.

  Further, since the tension in the transport direction and the tension in the direction opposite to the transport direction act on the medium 18, the medium 18 is transported while being stretched in a direction parallel to the transport direction.

  Then, since the medium 18 is conveyed with the wrinkles stretched, for example, the deformation of the medium 18 due to the contraction of the medium 18 when the fixing process is performed on the medium 18 on which the image is formed is prevented. Is done.

  By reducing the total length L of the suction pressure generation region 20D in the transport direction of the medium 18, the distance between the position gripped by the gripper 16 and the position attracted by the transport guide 20 becomes longer, and the inclination of the medium 18 is increased. It can be made smaller.

  In addition, the thickness range of the medium 18 used is 0.3 mm or less (so-called thin paper) in the case of a paper medium. The thickness condition of the medium 18 is appropriately determined according to the material of the medium 18.

  Further, by fixing the rear end side fixed portion 18B of the medium 18, it is possible to prevent the rear end side fixed portion 18B of the medium 18 from flapping. Contact to the part can be avoided.

  FIG. 4 is a block diagram illustrating a schematic configuration of a control system of the transport apparatus 10. As shown in the figure, the transport apparatus 10 includes a system controller 100 (a component of the fixed control means), a communication unit 102, a memory 106, a transport control unit 110, a gripper control unit 112, and a suction control unit 114. (Constituent element of the fixed control means) and the valve control unit 116.

  The system controller 100 includes a CPU (Central Processing Unit) 100A, a ROM (Read Only Memory) 100B, a RAM (Random Access Memory) 100C, and the like.

  The system controller 100 controls each part of the apparatus in an integrated manner, and functions as a memory controller for the built-in memory (ROM 100B, RAM 100C) and the external memory 106.

  Various data used in the transport apparatus 10 sent from the host computer 104 is taken into the transport apparatus 10 via the communication unit 102 and temporarily stored in the RAM 100C.

  The system controller 100 generates a command signal for each part of the apparatus based on various data stored in the RAM 100C, and sends the command signal to each part of the apparatus.

  The transport control unit 110 includes a driver circuit for driving motors and actuators (not shown) included in the transport system 13 based on a command signal sent from the system controller 100.

  The transport system 13 illustrated in FIG. 4 includes a motor, a gear, and a connecting member that rotate the first sprocket 12A (second sprocket 12B) illustrated in FIG.

  The gripper control unit 112 controls the operation of the gripper opening / closing mechanism 17 that opens and closes the gripper 16 illustrated in FIG. 1 based on a command signal sent from the system controller 100.

  The gripper opening / closing mechanism 17 shown in FIG. 4 includes an operating claw (not shown) that is slidably attached to the base frame 16A (see FIG. 1), a peristaltic mechanism (not shown) that swings the operating claw, and driving of the peristaltic mechanism. A source motor (not shown) is included.

  That is, the gripper control unit 112 includes a driver circuit of a motor that is a drive source of the gripper opening / closing mechanism 17.

  The adsorption control unit 114 controls the operation of the pump 36 based on a command signal sent from the system controller 100. That is, the adsorption control unit 114 functions as a pump driver that controls on / off of the pump 36, the number of rotations (pressure to be generated), and the like.

  The valve control unit 116 controls on / off of the valve 32 based on a command signal sent from the system controller 100.

  The transport device 10 includes an operation unit 120, a display unit 122, a sensor 124, and a position detection unit (encoder) 126.

  The operation unit 120 includes a user interface such as a keyboard, a touch panel, a mouse, and a joystick. A user (operator) can input necessary information by operating the operation unit 120.

  An operation signal sent from the operation unit 120 is sent to the system controller 100. Based on the operation signal acquired from the operation unit 120, the system controller 100 generates and sends a command signal to each unit of the apparatus.

  The display unit 122 is a display unit that displays the operation status and error information of the transport apparatus 10, and a liquid crystal display (liquid crystal monitor) or the like is applied thereto. By applying a touch panel liquid crystal display device, the operation unit 120 and the display unit 122 can be integrated.

  The sensor 124 includes various sensors arranged in each part of the apparatus. For example, a pressure sensor that detects the adsorption pressure of the conveyance guide 20, a temperature sensor that detects the temperature of each part of the apparatus and the temperature of the medium 18 (see FIG. 1), and the like are included.

  The position detection unit 126 detects the position (rear end position) of the medium 18 on the conveyance path of the medium 18 and sends the position information of the medium 18 to the system controller 100. The system controller 100 sends a command signal for switching the suction of the transport guide 20 to the suction control unit 114 based on the position information of the medium 18.

  Based on the command signal sent from the system controller 100, the suction portion 20B of the transport guide 20 that sucks the rear end side fixed portion 18B of the medium 18 is switched.

  As an example of the position detector 126, a rotary encoder attached to a motor that rotates the first sprocket 12A (or the second sprocket 12B) around which the chain 14 is wound, or the first sprocket 12A (or the second sprocket 12B). And a linear scale provided on the conveyance path of the medium 18 and an optical sensor provided on the conveyance path of the medium 18.

  In the configuration provided with an encoder and a linear scale as the position detection unit 126, the movement amount of the medium 18 can be grasped by counting the output pulses from the encoder (linear scale), and according to a preset count value. Thus, the suction unit 20B of the transport guide 20 can be switched sequentially.

  In this example, vacuum suction is performed by applying a negative pressure (vacuum) to the medium 18 to fix the rear end side fixed portion 18B of the medium 18 to the medium fixing surface 20A. However, an electrostatic force is applied to the medium fixing surface 20A. Electrostatic adsorption may be applied to cause the rear end side fixed portion 18B of the medium 18 to be fixed to the medium fixing surface 20A by electrostatic force, or fixing using a mechanical fixing member may be applied. Good.

[Description of suction switching control of transport guide]
Next, the suction switching control of the conveyance guide 20 will be described in detail. In the following description, the same or similar parts as those described above are denoted by the same reference numerals, and the description thereof is omitted. 5 (a) and 5 (b), the number of suction holes 20C and the arrangement of the suction holes 20C are different from those in FIG. 3 for convenience of illustration.

  FIGS. 5A and 5B are explanatory diagrams of the suction switching control of the transport guide 20, and FIG. 5A schematically shows a state before the suction unit 20B that generates the suction pressure is switched. FIG. 5B schematically shows a state after the adsorption unit 20B that generates the adsorption pressure is switched.

  During the period in which the rear end 18D of the medium 18 shown in FIG. 5A is located in the adsorption pressure generation region 20D (see FIG. 3) of the adsorption unit 20B1 (the adsorption unit 20B at the right end in the drawing), the adsorption unit 20B1 The adsorption is turned on, and the other adsorption parts (adsorption parts 20B, 20B3, 20B4,...) Are turned off.

  If it does so, the back surface of the rear end side fixed part 18B (area | region pinched | interposed by the broken line) of the medium 18 will be adsorb | sucked by adsorption | suction part 20B1.

  As the conveyance of the medium 18 progresses, as shown in FIG. 5B, the adsorption of the adsorption unit 20B2 is turned on before the rear end 18D of the medium 18 exits (immediately before) the adsorption pressure generation region 20D of the adsorption unit 20B1. When the rear end 18D of the medium 18 exits the adsorption pressure generation region 20D of the adsorption unit 20B1, the adsorption of the adsorption unit 20B1 is turned off.

  That is, before the rear end 18D of the medium 18 exits (just before) the adsorption pressure generation region 20D of the adsorption unit 20B (for example, the adsorption unit 20B1) on the upstream side in the same direction with respect to the adsorption unit 20B adjacent in the conveyance direction of the medium 18. The adsorption of the adsorption unit 20B (adsorption unit 20B2) on the downstream side in the same direction is turned on.

  Further, when the rear end 18D of the medium 18 exits the adsorption pressure generation region 20D of the adsorption unit 20B on the upstream side in the same direction, the adsorption of the adsorption unit 20B is turned off. The time difference between the timing at which the suction of the suction unit 20B on the downstream side in the transport direction of the medium 18 is turned on and the timing at which the suction of the suction unit 20B on the upstream side in the same direction is turned off is the transport speed of the medium 18 and the medium 18 It is determined according to the conveyance conditions such as the thickness (required adsorption pressure value).

  Further, the conveyance of the medium 18 proceeds, and the adsorption of the adsorption unit 20B3 is turned on before the rear end 18D of the medium 18 exits the adsorption pressure generation region 20D of the adsorption unit 20B2, and the rear end 18D of the medium 18 is adsorbed. When the adsorption pressure generation region 20D of the part 20B2 is exited, the adsorption of the adsorption part 20B2 is turned off.

  Further, when the conveyance of the medium 18 proceeds, the adsorption of the adsorption unit 20B3 is turned on, the adsorption of the adsorption unit 20B2 is turned off, and the adsorption of the adsorption unit 20B4 according to the position of the rear end 18D of the medium 18. Is turned on, and the suction of the suction portion 20B3 is turned off.

  In this way, according to the position of the rear end 18D of the medium 18, the plurality of suction portions 20B arranged in the conveyance direction of the medium 18 are sequentially switched from the upstream side to the downstream side in the same direction. .

  In this manner, by sequentially switching on and off the suction unit 20B constituting the transport guide 20 in accordance with the position of the rear end 18D of the medium 18, only a part of the upstream side of the center 18E in the transport direction of the medium 18 can be obtained. The medium 18 can be transported with the medium 18 fixed and without wrinkles or sagging.

  The conveyance guide 20 shown in the present example is arranged in a row immediately before the rear end 18D of the medium 18 exits the adsorption pressure generation region 20D of the adsorption unit 20B on the upstream side in the same direction with respect to the adsorption unit 20B adjacent in the conveyance direction of the medium 18. Since the rear end 18D of the medium 18 may be adsorbed by only one group of the adsorption holes 20C, even when the rear end 18D of the medium 18 is adsorbed by only one group of the adsorption holes 20C, the adsorption pressure is insufficient and the medium 18 The diameter of the suction holes 20C, the arrangement interval of the suction holes 20C, and the operating conditions of the pump 36 (see FIG. 3) are determined so that the suction is not removed.

  The medium (used medium) applied to the conveying apparatus 10 shown in this example is a single-sheet medium such as paper, a metal film, or a resin film, and may be any medium having a thickness that can be gripped by the gripper 16. .

[Description of Modified Examples of Transport Guide]
Next, a modified example of the transport guide 20 will be described.

  FIGS. 6A and 6B are explanatory views of a modified example of the transport guide described with reference to FIGS. FIG. 6A is a plan view of the conveyance guide 21, and FIG. 6B is a perspective side view showing the three-dimensional structure of the conveyance guide 21.

  The conveyance guide 21 shown in FIGS. 6A and 6B is aligned with a chamber member 21G in which a plurality of chambers 21F are formed under a suction plate 21E which is a plate-like member having suction holes 21C. It has the structure joined by being done.

  In addition, the broken line of Fig.6 (a) represents the partition position of each chamber 21F which comprises the chamber member 21G.

  FIG. 7 is an explanatory diagram of another modified example of the transport guide described with reference to FIGS. 1 to 5, and is a plan view illustrating the medium fixing surface 121 </ b> A of the transport guide 121.

  The conveyance guide 121 illustrated in FIG. 7 has an adsorption groove 121 </ b> C having a length corresponding to the entire width of the medium 18 used along the width direction. In the conveyance guide 121 illustrated in FIG. 7, four suction grooves 121C having the same length and the same width are formed for one suction portion 121B.

  Note that the shape, structure, and arrangement of the suction grooves 121C are not limited to the aspect illustrated in FIG. 7. It is possible to change, add, and delete as appropriate.

  According to the transport apparatus configured as described above, the front-end-side fixed portion 18A of the medium 18 is gripped by the gripper 16, is disposed below the gripper 16, and is disposed at a constant interval with the gripper 16. Further, a part of the upstream side of the center 18E in the transport direction of the medium 18 is attracted and held on the medium fixing surface 20A of the transport guide 20 as the rear end side fixed portion 18B, so that the inclination of the medium 18 during transport is further increased. The deformation of the medium 18 during conveyance (particularly, deformation in the vicinity of the fixed portions 18A and 18B) can be suppressed.

  Further, the rear side of the rear end side fixed portion 18B of the medium 18 is adsorbed while moving the front end side fixed portion 18A of the medium 18 in the transport direction, whereby a tension opposite to the transport direction is applied to the medium 18. As a result, the posture of the medium 18 can be maintained in a nearly flat state.

  Thus, since the medium 18 is conveyed while preventing the deformation of the medium 18, even when the medium 18 being conveyed is subjected to a drying process or a fixing process, wrinkles, curls, Occurrence of deformation such as cockle is prevented.

[Description of other modes of the transport guide]
Next, another aspect of the conveyance guide 20 described above will be described with reference to FIGS. FIG. 8 is a plan view illustrating the medium fixing surface 220 </ b> A of the transport guide 220.

  In the conveyance guide 220 shown in FIG. 8, in the adsorption unit 220 </ b> B adjacent in the conveyance direction of the medium 18, the central portion 220 </ b> E in the width direction perpendicular to the same direction in the adsorption unit 220 </ b> B on the upstream side in the same direction is downstream in the same direction. The suction part 220B is included in the structure.

  The “width direction center portion 220E” here is a portion including the width direction center 220F and having one or more suction holes 220C. FIG. 8 illustrates a mode in which the suction holes 220C of one third of the total number of suction holes 220C in the same direction are included as the central portion 220E in the width direction.

  8 represents the adsorption pressure generation region 220D of each adsorption part 220B.

  The conveyance guide 221 illustrated in FIG. 9 has suction grooves 221C radially formed on the medium fixing surface 221A from the upstream side to the downstream side in the conveyance direction of the medium 18 instead of the suction holes 220C of the conveyance guide 220 illustrated in FIG. Is formed.

  That is, on the medium fixing surface 221A of the suction portion 221B illustrated in FIG. 9, the medium 18 goes from the center 221F in the width direction to both ends in the same direction, and obliquely from the upstream side to the downstream side in the conveyance direction of the medium 18. An adsorption groove 221C is formed.

  FIGS. 10A and 10B are explanatory diagrams of the suction switching control of the conveyance guide 220 shown in FIG. 8, and FIG. 10A shows the state before the suction unit 220B that generates the suction pressure is switched. Is schematically illustrated, and FIG. 10B schematically illustrates a state after the adsorption unit 220B that generates the adsorption pressure is switched.

  As shown in FIG. 10A, the rear end 18D of the medium 18 has an adsorption unit 220B (adsorption) on the upstream side of the adsorption unit 220B (for example, the adsorption unit 220B1 and the adsorption unit 220B2) adjacent to the conveyance direction of the medium 18. Portion 220B1) and the downstream suction portion 220B (suction portion 220B2) overlap (position where suction holes 220C belonging to the upstream suction portion 220B and suction holes 220C belonging to the downstream suction portion 220B coexist). When reaching, the adsorption of the adsorption unit 220B2 on the downstream side is turned on.

  Further, in the state shown in FIG. 10A, the adsorption of the upstream adsorption unit 220B is kept on.

  Further, the conveyance of the medium 18 proceeds, and as shown in FIG. 10B, the rear end 18D of the medium 18 is in the adsorption unit 220B (for example, the adsorption unit 220B1 and the adsorption unit 220B2) adjacent in the conveyance direction of the medium 18. A position where the upstream suction part 220B (suction part 220B1) and the downstream suction part 220B (suction part 220B2) overlap (a suction hole 220C belonging to the upstream suction part 220B) and a suction belonging to the downstream suction part 220B When exiting the position where the holes 220C are mixed, the suction of the upstream suction part 220B (suction part 220B1) is turned off.

  In this way, at the timing when the region for generating the suction pressure is switched, the suction of the central portion 18F in the width direction of the rear end side fixed portion 18B of the medium 18 is maintained, but other than the central portion 18F in the same direction. By turning on the suction in the vicinity of the end portion, the central portion 18F in the width direction of the medium 18 is fixed first, and then the portion fixed to both end portions in the same direction is expanded to expand the medium 18. Is applied with a tension in a direction extending from the central portion 18F in the same direction toward both end portions 18G.

  Then, the medium 18 can be transported while increasing the slack of the medium 18 at the time of switching the region for generating the adsorption pressure.

  The suction switching control described with reference to FIG. 10 can also be applied to the transport guide 221 illustrated in FIG. Further, the modified example illustrated in FIG. 6 may be applied to the conveyance guides 220 and 221 described with reference to FIGS.

[Description of Conveying Device Provided with Conveying Guide having Other Configuration]
Next, a transport apparatus including a transport guide having another configuration will be described. FIG. 11 is an overall configuration diagram of a transfer apparatus 300 including a transfer guide 320 having another configuration. In FIG. 11, parts that are the same as or similar to those in FIG.

  A conveyance guide 320 illustrated in FIG. 11 includes a medium fixing surface 320A in which each suction portion 320B of the conveyance guide 320 is inclined.

  The medium fixing surface 320A of each suction portion 320B is inclined downward from the downstream side in the transport direction of the medium 18 toward the upstream side. The inclination of the medium fixing surface 320A is the same as the inclination of the hypotenuse of a triangle, where the distance H between the gripper 16 and the lowermost part of the medium fixing surface 320A is the height, and the entire length D of the medium 18 to be used is the hypotenuse length. Yes.

  According to the transport apparatus 300 illustrated in FIG. 11, the medium fixing surface 320 </ b> A is an inclined surface that faces downward from the downstream side in the transport direction of the medium 18, thereby generating the suction unit 320 </ b> B that generates the suction pressure of the transport guide 320. And the bend of the medium 18 at the boundary with the adsorbing portion 320B that does not generate the adsorbing pressure is prevented, and the occurrence of the distortion (deformation) of the medium 18 when the drying process or the fixing process is performed on the medium 18 is prevented. Is done.

  In addition, since only the suction part 320B in which the medium 18 is in contact with the medium fixing surface 320A can apply the suction pressure to the medium 18, the suction part 320B in which the suction pressure is originally turned off malfunctions. However, the medium 18 is not attracted by the malfunctioning suction portion 320B.

  By applying such a configuration, it is not necessary to use a configuration and control for preventing malfunction, the structure of the transport guide 320 can be simplified, and the adsorption pressure switching control of the transport guide 320 can be performed. Can be simple.

[Example of application to inkjet recording apparatus]
Next, an ink jet recording apparatus (image forming apparatus) to which the transport apparatus described above is applied will be described.

  FIG. 12 is an overall configuration diagram of an ink jet recording apparatus in which the transport apparatus described with reference to FIGS. 1 to 11 is applied to transport of a recording medium after image formation.

  An inkjet recording apparatus 410 shown in FIG. 12 uses an aqueous UV ink (a UV (ultraviolet) curable ink using an aqueous medium, an actinic ray curable liquid) on a sheet of paper (recording medium) P in an ink jet method. Inkjet recording apparatus for recording

  The ink jet recording apparatus 410 mainly includes a paper feeding unit 412 that feeds the paper P, and a processing liquid application unit 414 that applies a processing liquid to the surface (image forming surface) of the paper P fed from the paper feeding unit 412. The processing liquid drying processing unit 416 that performs the drying process of the paper P to which the processing liquid is applied by the processing liquid applying unit 414, and the aqueous UV ink is applied to the surface of the paper P that has been subjected to the drying processing by the processing liquid drying processing unit 416. An image forming unit 418 that records an image using an inkjet method, an ink drying processing unit 420 that performs drying processing of the paper P on which an image is recorded by the image forming unit 418, and a paper that is dried by the ink drying processing unit 420 A UV irradiation processing unit 422 that fixes the image by irradiating P with UV light (active light), and a paper discharge unit 424 that discharges the paper P subjected to the UV irradiation processing by the UV irradiation processing unit 422. Structure It is.

  As the paper P, general-purpose printing paper used in an offset printing machine or the like is used. Examples of general-purpose printing paper include coated paper (art paper, coated paper, lightweight coated paper, fine coated paper, etc.). The coated paper is obtained by applying a coating material on the surface of high-quality paper or neutral paper that has not been surface-treated to provide a coating layer.

<Paper Feeder>
The sheet feeding unit 412 mainly includes a sheet feeding table 430, a soccer device 432, a sheet feeding roller pair 434, a feeder board 436, a front pad 438, and a sheet feeding drum 440. Are fed one by one to the processing liquid application unit 414.

  The sheets P stacked on the sheet feed table 430 are pulled up one by one in order from the top by the soccer device 432 (suction fit 432A), and are fed to a pair of sheet feed rollers 434 (between a pair of upper and lower rollers 434A and 434B). Paper is fed.

  The paper P fed to the paper feed roller pair 434 is fed forward by a pair of upper and lower rollers 434A and 434B and placed on the feeder board 436. The paper P placed on the feeder board 436 is transported by a tape feeder 436A provided on the transport surface of the feeder board 436.

  Then, in the conveyance process, the retainer 436B presses against the conveyance surface of the feeder board 436, and the unevenness is corrected. The sheet P conveyed by the feeder board 436 has its leading end abutted against the front pad 438 so that the inclination is corrected, and is then transferred to the sheet feeding drum 440. Then, it is conveyed to the processing liquid application unit 414 by the paper supply drum 440.

<Processing liquid application part>
The treatment liquid application unit 414 mainly includes a treatment liquid application drum 442 that conveys the paper P, and a treatment liquid application unit 444 that applies a predetermined treatment liquid to the surface of the paper P conveyed by the treatment liquid application drum 442. A treatment liquid is applied (applied) to the surface of the paper P.

  The treatment liquid applied to the surface of the paper P is applied with a treatment liquid having a function of aggregating the color material in the aqueous UV ink ejected onto the paper P by the image forming unit 418 in the subsequent stage. By applying the treatment liquid onto the surface of the paper P and ejecting water-based UV ink, high-quality printing can be performed without causing landing interference or the like even when using general-purpose printing paper.

  The paper P transferred from the paper supply drum 440 of the paper supply unit 412 is transferred to the processing liquid application drum 442. The treatment liquid applying drum 442 conveys the paper P around the circumferential surface by rotating the gripper 442 </ b> A by gripping the tip end of the paper P with the gripper 442 </ b> A. The “tip of the paper P” here includes a portion gripped by the gripper 442A (another gripper described later) and its vicinity.

  In this conveyance process, the processing liquid is applied to the surface of the paper P by causing the application roller 444A to press and contact the surface of the paper P. In addition, the form which apply | coats a process liquid is not limited to roller application | coating, Other forms, such as an inkjet system and application | coating with a blade, are also applicable.

<Processing liquid drying processing section>
The processing liquid drying processing unit 416 mainly includes a processing liquid drying processing drum 446 that transports the paper P, a paper transport guide 448 that supports (guides) the back surface of the paper P, and a paper transported by the processing liquid drying processing drum 446. And a processing liquid drying processing unit 450 that blows hot air on the surface of P to dry it, and performs a drying process on the paper P with the processing liquid applied to the surface.

  The paper P transferred from the treatment liquid application drum 442 of the treatment liquid application unit 414 to the treatment liquid drying treatment drum 446 is gripped at the leading end by a gripper 446A provided in the treatment liquid drying treatment drum 446.

  Further, the back surface of the paper P is supported by the paper transport guide 448 with the front surface (the surface coated with the treatment liquid) facing inward. In this state, the paper P is conveyed by rotating the processing liquid drying processing drum 446.

  In the process of being transported by the processing liquid drying processing drum 446, hot air is blown onto the surface of the paper P from the processing liquid drying processing unit 450 installed inside the processing liquid drying processing drum 446, and the paper P is dried. As a result, the solvent component in the treatment liquid is removed, and an ink aggregation layer is formed on the surface of the paper P.

<Image forming part>
The image forming unit 418 mainly presses the image forming drum 452 that transports the paper P and the paper P that is transported by the image forming drum 452, and causes the paper P to adhere to the peripheral surface of the image forming drum 452. 454, inkjet heads 456C, 456M, 456Y, and 456K that discharge ink droplets of C, M, Y, and K colors on the paper P, an inline sensor 458 that reads an image recorded on the paper P, and an ink mist. A droplet of ink (water-based UV ink) of each color of C, M, Y, and K is formed on the surface of the paper P that includes the mist filter 460 to be captured and the drum cooling unit 462 and on which the treatment liquid layer is formed. To draw a color image on the surface of the paper P.

  The ink jet head applied to this example includes a piezoelectric method in which ink is ejected by utilizing the flexural deformation of a piezoelectric element, a thermal method in which ink is ejected by causing film boiling by heating the ink, and charged ink. Various discharge methods such as an electrostatic method in which the ink is landed on the recording medium by electrostatic force can be applied.

  In addition, the inkjet head applied to this example may be a line type head in which nozzles are formed over a length corresponding to the entire width of the paper P (the total length in the main scanning direction orthogonal to the transport direction of the paper P). Alternatively, a short serial head less than the full width of the paper P may be applied.

  The sheet P transferred from the processing liquid drying processing drum 446 of the processing liquid drying processing unit 416 to the image forming drum 452 is gripped by the gripper 452A provided in the image forming drum 452. Further, the sheet P is brought into close contact with the peripheral surface of the image forming drum 452 by passing the sheet P under the sheet pressing roller 454.

  The sheet P brought into close contact with the peripheral surface of the image forming drum 452 is adsorbed by the negative pressure generated in the suction holes formed on the peripheral surface of the image forming drum 452 and is adsorbed and held on the peripheral surface of the image forming drum 452. The

  When the paper P attracted and held on the peripheral surface of the image forming drum 452 passes through the ink droplet ejection area immediately below each of the inkjet heads 456C, 456M, 456Y, and 456K, the inkjet heads 456C, 456M, 456Y, From 456K, ink droplets of colors C, M, Y, and K are ejected onto the surface, and a color image is drawn on the surface.

  The ink deposited on the surface of the paper P reacts with the ink agglomerated layer formed on the surface of the paper P and is fixed on the surface of the paper P without causing feathering or bleeding. A high quality image is formed.

  When the paper P on which the image is formed by the inkjet heads 456C, 456M, 456Y, and 456K passes through the reading area of the inline sensor 458, the image formed on the surface is read.

  Image reading by the in-line sensor 458 is performed as necessary, and image defects (image abnormalities) such as ejection defects and density unevenness are inspected from the image reading data. The paper P that has passed the reading area of the in-line sensor 458 is transferred to the ink drying processing unit 420 after the suction is released.

<Ink drying processing section>
The ink drying processing unit 420 (drying processing means) includes an ink drying processing unit 468 that performs drying processing on the paper P conveyed by the chain gripper 464, and performs drying processing on the paper P after image formation. The liquid component remaining on the surface of the paper P is removed.

  A configuration example of the ink drying processing unit 468 includes an aspect including a heat source such as a halogen heater or an infrared (IR) heater, and a fan that blows air (gas, fluid) heated by the heat source onto the paper P.

  The leading edge of the sheet P transferred from the image forming drum 452 of the image forming unit 418 to the chain gripper 464 (components of the recording medium transport unit, which will be described in detail later) is gripped by a gripper 464D provided in the chain gripper 464.

  Further, the rear surface of the rear end of the paper P is sucked and held on the paper holding surface of the guide plate 472 arranged at a certain distance from the chain gripper 464. The “rear end of the paper P” here includes an area to be sucked and held and the vicinity thereof.

  By causing the rear surface of the rear end of the paper P to be sucked and held on the paper holding surface, the back end of the paper P is prevented from fluttering by the air flow from the ink drying processing unit 468, and the paper due to the back end flapping of the paper P is prevented. Contact of the rear end of P to the ink drying processing unit 468 and the like is prevented.

<UV irradiation processing part>
The UV irradiation processing unit 422 (active light irradiation means) includes a UV irradiation unit 474 and irradiates an image recorded using water-based UV ink with ultraviolet rays to fix the image on the surface of the paper P.

  A configuration example of the UV irradiation unit includes an aspect including an ultraviolet light source that generates UV light, an optical system that functions as a means for condensing the UV light, a means for deflecting the UV light, and the like.

  When the paper P conveyed by the chain gripper 464 reaches the UV light irradiation region of the UV irradiation unit 474, the UV irradiation processing is performed by the UV irradiation unit 474 installed inside the chain gripper 464.

  That is, the paper P that is gripped by the gripper and transported by the chain gripper 464 with the back surface of the rear end adsorbed and held by the paper holding surface is disposed at a position corresponding to the surface of the paper P in the transport path of the paper P. UV light is emitted from the UV irradiation unit 474. The image (ink) irradiated with UV light develops a curing reaction and is fixed on the surface of the paper P.

  The paper P that has been subjected to the UV irradiation processing is sent to the paper discharge unit 424 via the inclined conveyance path 470B. You may provide the cooling process part which performs the cooling process with respect to the paper P which passes the inclination conveyance path | route 470B.

<Paper output section>
The paper discharge unit 424 that collects the paper P that has undergone a series of image forming processes includes a paper discharge table 476 that stacks and collects the paper P.

  The chain gripper 464 (gripper 464D) releases the paper P on the paper discharge tray 476 and stacks the paper P on the paper discharge tray 476. The paper discharge table 476 stacks and collects the paper P released from the chain gripper 464. The paper discharge table 476 is provided with a sheet pad (not shown) (front sheet pad, rear sheet pad, horizontal sheet pad, etc.) so that the sheets P are stacked in an orderly manner.

  Further, the paper discharge tray 476 is provided so as to be lifted and lowered by a paper discharge tray lifting / lowering device (not shown). The discharge platform lifting device is controlled in conjunction with the increase / decrease of the sheets P stacked on the discharge table 476 so that the uppermost sheet P is always positioned at a certain height. The paper board 476 is moved up and down.

<Description of control system>
FIG. 13 is a block diagram showing a schematic configuration of a control system of the ink jet recording apparatus 410 shown in FIG.

  As shown in the figure, the inkjet recording apparatus 410 includes a system controller 500, a communication unit 502, an image memory 504, a conveyance control unit 510, a paper feed control unit 512, a processing liquid application control unit 514, a processing liquid drying control unit 516, An image formation control unit 518, an ink drying control unit 520, a UV irradiation control unit 522, a paper discharge control unit 524, an operation unit 530, a display unit 532, and the like are provided.

  The system controller 500 functions as a control unit that performs overall control of each unit of the inkjet recording apparatus 410 and also functions as a calculation unit that performs various types of calculation processing. The system controller 500 includes a CPU (Central Processing Unit) 500A, a ROM (Read Only Memory) 500B, and a RAM (Random Access Memory) 500C.

  The system controller 500 also functions as a memory controller that controls the writing of data to the ROM 500B, the RAM 500C, and a memory (not shown), and the reading of data from these memories.

  FIG. 2 illustrates an example in which the memory such as the ROM 500B and the RAM 500C is incorporated in the system controller 500, but the memory such as the ROM 500B and the RAM 500C may be provided outside the system controller 500.

  The communication unit 502 includes a required communication interface, and transmits and receives data to and from the host computer 503 connected to the communication interface.

  The image memory 504 functions as a temporary storage unit for various data including image data, and data is read and written through the system controller 500. Image data captured from the host computer via the communication unit 502 is temporarily stored in the image memory 504.

  The conveyance control unit 510 controls the operation of the conveyance system 411 of the paper P in the inkjet recording apparatus 410 (conveyance of the paper P from the paper supply unit 412 to the paper discharge unit 424). The transport system 411 includes a tape feeder 436A in the paper feeding unit 412 illustrated in FIG. 12, a front pad 438, a paper feeding drum 440, a processing liquid application drum 442 in the processing liquid application unit 414, and a processing liquid in the processing liquid drying processing unit 416. The image forming drum 452 in the image forming unit 418, the ink drying processing unit 420, the UV irradiation processing unit 422, and the chain gripper 464 used in common by the paper discharge unit 424 are included.

  The paper feed controller 512 controls the operation of each part of the paper feed unit 412 such as driving of the pair of paper feed rollers 434 and driving of the tape feeder 436A in accordance with a command from the system controller 500.

  The processing liquid application control unit 514 controls the operation of each part of the processing liquid application unit 414 such as the operation of the processing liquid application unit 444 (processing liquid application amount, application timing, etc.) in accordance with a command from the system controller 500. .

  The processing liquid drying control unit 516 controls the operation of each unit of the processing liquid drying processing unit 416 in response to a command from the system controller 500. That is, the processing liquid drying control unit 516 controls the operation of the processing liquid drying processing unit 450 (see FIG. 12), such as the drying temperature, the flow rate of the drying gas, and the injection timing of the drying gas.

  The image formation control unit 518 controls ink droplet ejection (ejection) from the image formation unit 418 (inkjet heads 456C, 456M, 456Y, 456K) in accordance with a command from the system controller 500.

  That is, the image formation control unit 518 in FIG. 13 includes an image processing unit that forms dot data from input image data, a drive waveform generation unit that generates a drive voltage waveform, and a drive waveform storage unit that stores a drive voltage waveform. And a driver circuit (head driver) that supplies a drive voltage having a drive waveform corresponding to the dot data to each of the inkjet heads 456C, 456M, 456Y, and 456K.

  In the image processing unit, color separation (separation) processing for separating input image data (raster data represented by digital values from 0 to 255) into RGB colors, color conversion processing for converting RGB into CMYK, and gamma Correction processing such as correction and unevenness correction, and halftone processing for converting each color data of M values into each color data of N values (M> N, M is an integer of 3 or more, N is an integer of 2 or more) are performed.

  Based on the dot data generated through the processing by the image processing unit, the droplet ejection timing and ink ejection amount at each pixel position are determined, and the drive voltage corresponding to the droplet ejection timing and ink ejection amount at each pixel position is determined. The generated drive voltage is supplied to the inkjet heads 456C, 456M, 456Y, and 456K, and dots are formed at the respective pixel positions by the ink droplets ejected from the inkjet heads 456C, 456M, 456Y, and 456K.

  The ink drying control unit 520 controls the operation of the ink drying processing unit 420 according to a command from the system controller 500. That is, the ink drying control unit 520 controls the operation of the ink drying processing unit 468 (see FIG. 12) such as the drying temperature, the flow rate of the drying gas, and the ejection timing of the drying gas.

  The UV irradiation control unit 522 controls the irradiation amount of UV light (UV light intensity (irradiation amount)) by the UV irradiation processing unit 422 according to a command from the system controller 500, and sets the irradiation timing of the UV light. Control.

  The paper discharge control unit 524 controls the operation of the paper discharge unit 424 so that the paper P is stacked on the paper discharge table 476 in response to a command from the system controller 500.

  The operation unit 530 includes operation members (operation means) such as operation buttons, a keyboard, and a touch panel, and sends operation information input from the operation means to the system controller 500. The system controller 500 executes various processes in accordance with the operation information sent from the operation unit 530.

  The display unit 532 includes a display device such as an LCD panel, and displays various kinds of setting information, abnormality information, and the like on the display device in response to a command from the system controller 500.

  In the control system in FIG. 4 and the control system in FIG. 13, processing units having the same or similar names and processing units having substantially the same function can be shared as appropriate.

  The conveying apparatus described above can be appropriately changed, added, and deleted without departing from the spirit of the present invention. Moreover, it is also possible to make a processing apparatus by combining the transport apparatus and the processing apparatus (see FIGS. 1 and 11) described above.

  In addition, the transport device described above includes a first fixing step for gripping the front-side fixed portion of the single-sheet medium, and a transport guide in which a plurality of suction portions are arranged along the transport direction of the medium. Medium transport including a second fixing step of fixing the fixed portion on the end side, and a transporting step of transporting the medium by moving the front-end fixed portion of the medium in the transport direction with the rear end fixed portion fixed. In the method, the second fixing step can realize a medium transport method in which the on / off state of the suction unit is sequentially switched from the upstream side to the downstream side in the medium transport direction according to the rear end position of the medium.

[Invention disclosed in this specification]
As will be understood from the description of the embodiments of the invention described in detail above, the present specification includes disclosure of various technical ideas including at least the invention described below.

  (First aspect): In a medium transport apparatus that transports sheets in the sheet transport direction, a first fixing unit that grips a tip-side fixed portion that is downstream of the center in the medium transport direction, and a first fixing unit And a plurality of fixing portions each having a medium fixing surface arranged at a predetermined interval below the first fixing means and arranged along the conveying direction. The length of the fixed area on the medium fixing surface in the transport direction is less than a quarter of the total length in the transport direction of the minimum size medium used in the medium transport device, and transport of the transported medium Corresponding to the position of the upstream end in the transport direction of the medium to be transported, and fixed and fixed by a plurality of fixing portions corresponding to the position of the upstream end in the transport direction of the transported medium. Release upstream in the transport direction Medium conveying device including a fixed control means for switching sequentially, the to Luo downstream.

  According to the first aspect, when gripping and transporting the front end fixed portion of the sheet medium, the rear end fixed portion upstream from the center in the medium transport direction is the front end fixed portion. The fixed portion of the rear end side fixed portion and the release of the fixed state are switched in accordance with the position of the upstream end in the transport direction of the medium to be transported, which is fixed to the medium holding surface below the fixed position. The inclination of the medium at the time is prevented from becoming steep, and the deformation of the medium at the time of conveyance is prevented.

  Further, by fixing the fixed portion on the rear end side of the medium, tension in the direction opposite to the transport direction can be applied to the medium to be transported, and deformation of the medium during transport is prevented.

  (Second aspect): In the medium transport apparatus according to the first aspect, the fixing control means transports the medium transported through the fixed region of the fixed part on the upstream side in the transport direction with respect to the fixed part adjacent to the transport direction. When the upstream end of the medium comes out, the fixing of the medium to be transported by the upstream fixing portion in the transport direction is released.

  According to the second aspect, fixing of the fixed portion after the medium to be transported passes through the fixed region is released, whereby the fixing of the fixed portion on the rear end side of the medium to be transported is sequentially switched.

  A mode provided with a detecting means for detecting the position of the upstream end of the transported medium in the transport direction, or the upstream of the transport direction of the medium based on the transport speed of the medium and the total length of the medium by detecting the position of the transported medium A mode provided with calculation means for calculating the position of the side end is preferable.

  (Third aspect): In the medium transporting apparatus according to the first aspect or the second aspect, the fixing control unit is transported to a fixed region in the fixed part on the downstream side in the transport direction with respect to the fixed part adjacent to the transport direction. When the rear end side fixed part of the medium reaches, fixing of the medium to be conveyed by the downstream fixing part is started.

  According to the third aspect, when the rear end side fixed portion of the medium to be transported reaches the fixing region, the fixing of the rear end side fixed portion of the medium to be transported is started by starting the fixing by the fixing portion. It is switched in order.

  It is preferable that the fixing start timing is set at the same time as the fixing release timing by the fixing portion on the upstream side in the transport direction or before the fixing release timing by the fixing portion on the upstream side in the transport direction.

  (Fourth aspect): In the medium conveying apparatus according to any one of the first to third aspects, the second fixing means includes an adsorbing means that adsorbs by applying an adsorption pressure to the back side of the medium to be conveyed. Yes.

  In the fourth aspect, an aspect including an adsorption pressure generating means for generating an adsorption pressure (negative pressure) and a connection switching means for switching the connection between the adsorption pressure generating means and each fixing portion is preferable.

  (Fifth aspect): In the medium transporting apparatus according to any one of the first to fourth aspects, the second fixing means is a central part of the fixing part on the upstream side in the transport direction with respect to the fixing part adjacent to the transport direction. Has a structure that enters the fixed region on the downstream side in the transport direction.

  According to the fifth aspect, the fixing portion is structured such that the central portion of the fixing portion on the upstream side in the transport direction enters the fixing region on the downstream side in the transport direction, thereby fixing the fixed portion on the rear end side of the medium. The cut can be eliminated.

  (Sixth aspect): The medium conveying apparatus according to any one of the first to fifth aspects, further comprising pressure generating means for generating an adsorption pressure on the medium fixing surface, and the medium fixing surface is connected to the pressure generating means. A plurality of suction holes for applying suction pressure to the medium to be conveyed are formed two-dimensionally.

  In the sixth aspect, as the arrangement of the suction holes, a square lattice arrangement, a radial arrangement, a concentric arrangement, or the like can be applied.

  In the sixth aspect, the fixed control means functions as switching control means for switching on / off of suction by a plurality of suction portions.

  (Seventh aspect): In the medium conveying apparatus according to any one of the first to fifth aspects, the medium fixing surface has a center in a direction in which a plurality of adsorption grooves that generate adsorption pressure are orthogonal to the conveyance direction of the fixed region To the both ends.

  According to the seventh aspect, the medium is extended from the center in the direction orthogonal to the transport direction to both ends, so that deformation of the medium, generation of wrinkles, and the like can be prevented.

  (Eighth aspect): In the medium conveying apparatus according to any one of the first to seventh aspects, the medium fixing surface for each fixing portion is a downward inclined surface from the downstream side to the upstream side in the conveying direction.

  According to the eighth aspect, by making the medium fixing surface an inclined surface, deformation of the medium in the vicinity of the front end side fixed portion and in the vicinity of the rear end side fixed portion is prevented.

  (Ninth aspect): Image forming means for forming an image on a sheet of medium, medium conveying device for conveying the medium on which the image is formed by the image forming means in the conveying direction, and processing for processing the conveyed medium And an image forming apparatus including the medium conveyance device according to any one of the first aspect to the eighth aspect.

  According to the ninth aspect, in the image forming apparatus that forms an image on a single-sheet medium, it is possible to obtain the same functions and effects as those of the medium conveying apparatus according to any one of the first to eighth aspects.

  In other words, it is possible to prevent the medium from being steeply inclined during conveyance, and by fixing the fixed portion on the rear end side of the medium, tension in the direction opposite to the conveyance direction can be applied to the medium to be conveyed. And deformation of the medium during conveyance is prevented.

  (Tenth aspect): In the image forming apparatus according to the ninth aspect, the processing means includes a drying processing unit that performs a drying process on the conveyed medium.

  According to the tenth aspect, deformation of the medium in the drying process after image formation is prevented.

  (Eleventh Aspect): In the image forming apparatus according to the ninth aspect or the tenth aspect, the processing means includes a fixing processing section that performs an image fixing process on the medium on which the image is formed by the image forming means.

  According to the eleventh aspect, deformation of the medium in the fixing process after image formation is prevented.

  (Twelfth aspect): In the image forming apparatus according to the eleventh aspect, the image forming means forms an image using a liquid that is cured by irradiation with actinic rays, and the fixing processing section forms an image by the image forming means. An actinic ray irradiating unit for irradiating the activated medium with actinic rays.

  According to the twelfth aspect, the shrinkage and curling of the medium when the liquid cured by irradiation with actinic rays is cured are prevented.

  (Thirteenth aspect): In a medium transport method for transporting a sheet of paper in the transport direction of the sheet, the gripped medium is transported by gripping the distal-side fixed portion downstream from the center in the transport direction of the medium to be transported. When moving along the direction, a medium fixing surface is provided below the position where the tip side fixed part is gripped and spaced apart by a certain distance. A rear end side fixed portion upstream of the center in the transport direction of the medium to be transported in each of the fixed regions of the plurality of fixed portions having a length of less than a quarter and arranged along the transport direction A medium transporting method in which fixing and releasing of fixing by a plurality of fixing portions are sequentially switched from the upstream side to the downstream side in the transport direction in accordance with the position of the upstream end in the transport direction of the transported medium.

  DESCRIPTION OF SYMBOLS 10 ... Conveying device, 14 ... Chain, 16 ... Gripper, 18 ... Medium, 20, 21, 121, 220, 221, 320 ... Conveying guide, 20A, 21A, 220A, 221A, 320A ... Medium fixing surface, 20B, 21B, 121B, 220B, 221B ... adsorption unit, 32 ... valve, 36 ... pump, 100 ... system controller, 110 ... conveyance control unit, 112 ... gripper control unit, 114 ... adsorption control unit, 116 ... valve control unit

Claims (10)

In the medium transport device for transporting in the sheet transport direction,
First fixing means for gripping a tip-side fixed portion downstream of the center in the transport direction of the medium;
Moving means for moving the first fixing means along the transport direction;
A plurality of fixing portions each having a medium fixing surface arranged at a predetermined interval below the first fixing means and arranged along the transport direction; The length in the transport direction has a structure that is less than a quarter of the total length in the transport direction of the smallest size medium used in the medium transport device, and the length of the transported medium from the center in the transport direction A second fixing means for fixing the rear end side fixed portion on the upstream side,
A fixing control means for sequentially switching fixing and releasing of the fixing by the plurality of fixing portions from the upstream side to the downstream side in the transport direction corresponding to the position of the upstream end of the transported medium in the transport direction;
Equipped with a,
The medium transporting device according to claim 1, wherein the medium fixing surface for each of the fixing units is a downward inclined surface from the downstream side to the upstream side in the transport direction .   When the upstream end of the transported medium of the transported medium exits the fixed region of the fixed section on the upstream side in the transport direction with respect to the fixed section adjacent to the transport direction, the fixing control means The medium transport apparatus according to claim 1, wherein the transported medium is released from being fixed by a fixing unit on the upstream side of the medium.   When the rear end side fixed part of the medium to be transported reaches the fixed region in the fixed part on the downstream side in the transport direction for the fixed part adjacent to the transport direction, the fixing control unit fixes the downstream side. The medium transport apparatus according to claim 1, wherein fixing of the transported medium by a unit is started.   4. The medium conveying apparatus according to claim 1, wherein the second fixing unit includes an adsorption unit that performs adsorption by applying an adsorption pressure to a back side of the medium to be conveyed. 5. Pressure generating means for generating an adsorption pressure on the medium fixing surface;
The medium fixing surface is connected to said pressure generating means, according to the any one of claims 1 to suction holes are formed in a two-dimensional shape to act the suction pressure to the medium to be conveyed 4 Medium transport device. The medium fixing surface, in any one of 4 claims 1 in which a plurality of suction grooves for generating suction pressure is formed radially toward both ends from the center in the direction perpendicular to the conveying direction of the fixed region The medium conveying apparatus as described. Image forming means for forming an image on a sheet medium;
A medium conveying apparatus for conveying the medium on which the image is formed by the image forming means in the conveying direction;
Processing means for performing processing on the transported medium;
With
The medium conveying apparatus, an image forming apparatus including the medium transporting device according to any one of claims 1 to 6. The image forming apparatus according to claim 7 , wherein the processing unit includes a drying processing unit that performs a drying process on the conveyed medium. The processing means, the image forming apparatus according to claim 7 or 8 including a fixing section which conducts a fixing process of the image to the medium on which the image has been formed by said image forming means. The image forming means forms an image using a liquid that is cured by irradiation with actinic rays,
The image forming apparatus according to claim 9 , wherein the fixing processing unit includes an actinic ray irradiation unit that irradiates the medium on which the image is formed by the image forming unit with actinic rays.

Images