Printing apparatus

Abstract

To prevent the recording medium from falling out of the transmission unit while suppressing damage to the leading edge of the recording medium. [Solution] The printing apparatus comprises a transport unit that transports a recording medium in the transport direction while gripping and holding the tip of the recording medium with gripping claws, a printing unit that prints on the recording medium while it is being transported, a gripping state detection unit that detects the gripping state of the gripping claws with respect to the recording medium, and a determination unit that determines whether or not there is an abnormality in the gripping state of the gripping claws based on the detection result of the gripping state detection unit.

Description

Technical Field

[0001] The present invention relates to a printing apparatus. Background Art

[0002] As prior art of printing apparatuses such as offset sheet-fed printing presses, there is, for example, the one disclosed in Patent Document 1. The printing apparatus described in Patent Document 1 includes a conveying section that conveys a sheet-shaped recording medium such as a sheet of paper in a conveying direction in a state where a leading end portion of the sheet-shaped recording medium is gripped and held by grippers. The conveying section includes a blanket cylinder, an impression cylinder, a first transfer cylinder, a second transfer cylinder, and a reversing cylinder, and the blanket cylinder and the impression cylinder function as a printing section that performs printing on the recording medium being conveyed. Prior Art Literature Patent Documents

[0003] Patent Document 1 Japanese Patent Application Laid-Open No. 2002-264301 Summary of the Invention Problems to be Solved by the Invention

[0004] Incidentally, in the printing apparatus described in Patent Document 1, when the gripping amount of the grippers with respect to the recording medium is insufficient, the holding force of the recording medium by the grippers becomes insufficient, which may cause the recording medium to fall off the conveying section. Further, when the gripping amount of the grippers with respect to the recording medium is excessive, the leading end of the recording medium may interfere with the base of the grippers, causing damage such as bending or tearing to the leading end portion of the recording medium.

[0005] Accordingly, an object of the present invention is to provide a printing apparatus that can suppress damage to the leading end portion of a recording medium while suppressing falling off of the recording medium from a conveying section. Means for Solving the Problems

[0006] One aspect of the printing apparatus of the present invention is A transport unit that holds the tip of the recording medium with gripping claws and transports the recording medium in the transport direction, A printing unit that prints on the recording medium while it is being transported, A gripping state detection unit that detects the gripping state of the gripping claws on the recording medium, The system includes a determination unit that determines whether or not there is an abnormality in the gripping state of the gripping claws based on the detection result of the gripping state detection unit. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress damage to the leading edge of the recording medium while preventing the recording medium from falling out of the transport section. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic front view of the inkjet printing apparatus according to this embodiment. [Figure 2] Figure 2 is a schematic enlarged view of Part II in Figure 1. [Figure 3] Figure 3 is a schematic diagram as seen from Part III in Figure 2. [Figure 4A] Figure 4A shows an image captured when there are no abnormalities in the gripping state of the multiple gripping claws on the surface of the recording medium. [Figure 4B] Figure 4B shows an image captured when there is an abnormality in the gripping state of the multiple gripping claws on the surface of the recording medium. [Figure 4C] Figure 4C shows an image captured when there is an abnormality in the gripping state of the multiple gripping claws on the surface of the recording medium. [Figure 4D] Figure 4D shows an image captured when there is an abnormality in the gripping state of the multiple gripping claws on the surface of the recording medium. [Figure 5A] Figure 5A shows an image captured when there are no abnormalities in the gripping state of the multiple gripping claws against the back surface of the recording medium. [Figure 5B]Figure 5B shows an image captured when there is an abnormality in the gripping state of the multiple gripping claws on the back surface of the recording medium. [Figure 6] Figure 6 is a control block diagram of the inkjet printing apparatus according to this embodiment. [Modes for carrying out the invention]

[0009] The following description of this embodiment will be made with reference to the drawings. In this embodiment, the transport direction refers to the direction in which the recording medium is transported. The downstream side refers to the downstream side of the transport direction, and the upstream side refers to the upstream side of the transport direction. The transport width direction refers to the direction perpendicular to the transport direction. In the drawings, "FD" refers to the transport direction, and "WD" refers to the transport width direction.

[0010] The configuration of the inkjet printing apparatus 10 according to this embodiment will be described with reference to Figures 1 to 5B. Figure 1 is a schematic front view of the inkjet printing apparatus 10 according to this embodiment. Figure 2 is a schematic enlarged view of part II in Figure 1. Figure 3 is a schematic view from part III in Figure 2. Figure 4A shows an image taken when there is no abnormality in the gripping state of the plurality of gripping claws 24 on the surface Pa of the recording medium P. Figures 4B to 4D show images taken when there is an abnormality in the gripping state of the plurality of gripping claws 24 on the surface Pa of the recording medium P. Figure 5A shows an image taken when there is no abnormality in the gripping state of the plurality of gripping claws 24 on the back surface Pb of the recording medium P. Figure 5B shows an image taken when there is an abnormality in the gripping state of the plurality of gripping claws 24 on the back surface Pb of the recording medium P.

[0011] As shown in Figure 1, the inkjet printing apparatus 10 according to this embodiment is a single-pass printing apparatus that prints (forms an image) on a sheet-shaped recording medium P while transporting it using a transport method. In addition to paper such as plain paper and coated paper, various media such as cloth and resin film can be used as the recording medium P.

[0012] An inkjet printing apparatus 10 includes a printing apparatus main body 12 extending in the left-right direction in FIG. 1. The printing apparatus main body 12 has a center frame 14, a first side frame 16 disposed on one side of the center frame 14, and a second side frame 18 disposed on the other side of the center frame 14.

[0013] The inkjet printing apparatus 10 includes a conveyance unit 20 that conveys a sheet-shaped recording medium P in the conveyance direction, and the conveyance unit 20 is provided on the center frame 14. The specific configuration of the conveyance unit 20 is as follows.

[0014] As shown in FIG. 1, the conveyance unit 20 has a printing cylinder 22 rotatably provided on the center frame 14, and the printing cylinder 22 carries the recording medium P and rotates. A plurality of grippers 24 that grip and hold the leading end portion of the recording medium P are provided on the outer peripheral surface side of the printing cylinder 22. The plurality of grippers 24 of the printing cylinder 22 are divided into a plurality of (for example, three) gripper groups 24G, and the plurality of gripper groups 24G are arranged at equal intervals on the outer peripheral surface of the printing cylinder 22. The plurality of grippers 24 (only one is illustrated) in each gripper group 24G of the printing cylinder 22 are arranged at intervals along the conveyance width direction. Note that the grippers 24 are also referred to as holding claws that hold the leading end portion of the recording medium P.

[0015] A plurality of suction units (not illustrated) that suck the recording medium P are provided on the outer peripheral surface of the printing cylinder 22. The suction method of the plurality of suction units of the printing cylinder 22 may be either suction adsorption or electrostatic adsorption.

[0016] The conveyance unit 20 has a rotary motor 26 (see FIG. 4) as a drive source for rotating the printing cylinder 22, and the rotary motor 26 is provided at an appropriate position of the center frame 14. In a state where the leading end portion of the recording medium P is gripped and held by the plurality of grippers 24 of any one of the gripper groups 24G of the printing cylinder 22, the printing cylinder 22 is rotated by driving the rotary motor 26, thereby conveying the recording medium P in the conveyance direction.

[0017] As shown in Fig. 1, the conveying section 20 includes an upstream cylinder 28 that delivers the recording medium P to the printing cylinder 22, and the upstream cylinder 28 is rotatably provided on the upstream side of the printing cylinder 22 in the center frame 14. The upstream cylinder 28 is arranged close to the printing cylinder 22, and rotates while carrying the recording medium P. The upstream cylinder 28 is configured to rotate in a direction opposite to the rotation direction of the printing cylinder 22 in association with the rotation of the printing cylinder 22. The diameter of the upstream cylinder 28 is 1 / 3 of the diameter of the printing cylinder 22, and the upstream cylinder 28 is configured to rotate one full rotation when the printing cylinder 22 rotates by 1 / 3 of a full rotation.

[0018] On the outer peripheral surface side of the upstream cylinder 28, a plurality of gripping claws 30 (only one gripping claw 30 is illustrated) for gripping and holding the leading end of the recording medium P are provided. The plurality of gripping claws 30 of the upstream cylinder 28 are arranged at intervals in the conveying width direction. The plurality of gripping claws 30 of the upstream cylinder 28 and the plurality of gripping claws 24 of any one claw group 24G of the printing cylinder 22 perform a gripping switching operation for the recording medium P while being close to each other. The plurality of gripping claws 24 of any one claw group 24G of the printing cylinder 22 receive and hold the leading end of the recording medium P from the plurality of gripping claws 30 of the upstream cylinder 28. Note that the gripping claws 30 are also referred to as holding claws that hold the leading end of the recording medium P.

[0019] As shown in Fig. 1, the conveying section 20 includes a first downstream cylinder 32 that receives the single-side printed or double-side printed recording medium P from the printing cylinder 22. The first downstream cylinder 32 is rotatably provided on the downstream side of the printing cylinder 22 in the center frame 14. The first downstream cylinder 32 is arranged close to the printing cylinder 22, and rotates while carrying the recording medium P. The first downstream cylinder 32 is configured to rotate in a direction opposite to the rotation direction of the printing cylinder 22 in association with the rotation of the printing cylinder 22. The diameter of the first downstream cylinder 32 is 1 / 3 of the diameter of the printing cylinder 22, and the first downstream cylinder 32 is configured to rotate one full rotation when the printing cylinder 22 rotates by 1 / 3 of a full rotation.

[0020] Multiple gripping claws 34 (only one gripping claw 34 is shown) are provided on the outer circumferential surface of the first downstream cylinder 32 to grip and hold the leading edge of the recording medium P. The multiple gripping claws 34 of the first downstream cylinder 32 are spaced apart in the transport width direction. The multiple gripping claws 34 of the first downstream cylinder 32 and the multiple gripping claws 24 of any claw group 24G of the printing cylinder 22 perform the gripping and re-gripping operation of the recording medium P while in close proximity to each other. The multiple gripping claws 24 of the first downstream cylinder 32 receive and hold the leading edge of the recording medium P that has been printed on one side or on both sides from the multiple gripping claws 24 of any claw group 24G of the printing cylinder 22. The gripping claws 34 are also referred to as holding claws that hold the leading edge of the recording medium P.

[0021] As shown in Figure 1, the transport unit 20 has a second downstream cylinder 36 that receives a single-sided or double-sided printed recording medium P from the first downstream cylinder 32. The second downstream cylinder 36 is rotatably mounted on the center frame 14 downstream of the first downstream cylinder 32. The second downstream cylinder 36 is positioned close to the first downstream cylinder 32 and rotates while carrying the recording medium P. The second downstream cylinder 36 is configured to rotate in the same direction as the rotation of the printing cylinder 22, in conjunction with the rotation of the printing cylinder 22. The diameter of the second downstream cylinder 36 is 1 / 3 of the diameter of the printing cylinder 22, and the first downstream cylinder 32 is configured to rotate 1 full turn when the printing cylinder 22 rotates 1 / 3 of a turn.

[0022] Multiple gripping claws 38 (only one gripping claw 38 is shown) are provided on the outer circumferential surface of the second downstream body 36 to grip and hold the tip of the recording medium P. The multiple gripping claws 38 of the second downstream body 36 are spaced apart in the transport width direction. The multiple gripping claws 38 of the second downstream body 36 and the multiple gripping claws 34 of the first downstream body 32 perform the gripping and re-gripping operation of the recording medium P while in close proximity to each other. The multiple gripping claws 38 of the second downstream body 36 receive and hold the tip of the recording medium P, whether single-sided or double-sided printed, from the multiple gripping claws 34 of the first downstream body 32. The gripping claws 38 are also referred to as holding claws that hold the tip of the recording medium P.

[0023] As shown in Figure 1, the transport unit 20 has a third downstream cylinder 40 that receives a single-sided or double-sided printed recording medium P from the second downstream cylinder 36. The third downstream cylinder 40 is rotatably mounted on the center frame 14 downstream of the second downstream cylinder 36. The third downstream cylinder 40 is positioned close to the second downstream cylinder 36 and rotates while carrying the recording medium P. The third downstream cylinder 40 is configured to rotate in the opposite direction to the rotation of the printing cylinder 22 in conjunction with the rotation of the printing cylinder 22. The diameter of the third downstream cylinder 40 is 1 / 3 of the diameter of the printing cylinder 22, and the third downstream cylinder 40 is configured to rotate 1 full turn when the printing cylinder 22 rotates 1 / 3 of a turn.

[0024] Multiple gripping claws 42 (only one gripping claw 42 is shown) are provided on the outer circumferential surface of the third downstream body 40 to grip and hold the tip of the recording medium P. The multiple gripping claws 42 of the third downstream body 40 are spaced apart in the transport width direction. The multiple gripping claws 42 of the third downstream body 40 and the multiple gripping claws 38 of the second downstream body 36 perform the gripping and re-gripping operation of the recording medium P while in close proximity to each other. The multiple gripping claws 42 of the third downstream body 40 receive and hold the tip of the recording medium P, whether single-sided or double-sided printed, from the multiple gripping claws 38 of the second downstream body 36. The gripping claws 42 are also referred to as holding claws that hold the tip of the recording medium P.

[0025] As shown in Figure 1, the transport unit 20 has a reversing front cylinder 44 that receives the single-sided printed recording medium P from the third downstream cylinder 40. The reversing front cylinder 44 is rotatably mounted on the center frame 14 and is positioned opposite the printing cylinder 22. The reversing front cylinder 44 is positioned close to the third downstream cylinder 40 and rotates while carrying the recording medium P. The reversing front cylinder 44 is configured to rotate independently of the rotation of the printing cylinder 22, but in the same direction as the rotation of the printing cylinder 22. The diameter of the reversing front cylinder 44 is 2 / 3 of the diameter of the printing cylinder 22.

[0026] Multiple gripping claws 46 (only one gripping claw 46 is shown) are provided on the outer circumferential surface of the front reversing cylinder 44 to grip and hold the leading edge of the recording medium P. The multiple gripping claws 46 of the front reversing cylinder 44 are spaced apart in the transport width direction. The multiple gripping claws 46 of the front reversing cylinder 44 and the multiple gripping claws 42 of the third downstream cylinder 40 perform the gripping and re-gripping operation of the recording medium P while in close proximity to each other. The multiple gripping claws 46 of the front reversing cylinder 44 receive and hold the leading edge of the recording medium P that has been printed on one side from the multiple gripping claws 42 of the third downstream cylinder 40. The gripping claws 46 are also referred to as holding claws that hold the leading edge of the recording medium P.

[0027] The outer circumferential surface of the inverting front cylinder 44 is provided with a plurality of adsorption parts (not shown) for adsorbing the recording medium P. The adsorption method of the plurality of adsorption parts of the inverting front cylinder 44 may be either suction adsorption or electrostatic adsorption. The plurality of adsorption parts of the inverting front cylinder 44 are connected to an adsorption force adjustment unit 48 (see Figure 4) for adjusting the adsorption force. The adsorption force adjustment unit 48 corresponds to a tension adjustment unit that adjusts the tension in the vertical direction of the recording medium P supported on the outer circumferential surface of the inverting front cylinder 44 by adjusting the adsorption force of the plurality of adsorption parts of the inverting front cylinder 44. Alternatively, instead of adjusting the adsorption force of the plurality of adsorption parts of the inverting front cylinder 44, the tension of the recording medium P supported on the outer circumferential surface of the inverting front cylinder 44 may be adjusted by pressing the recording medium P toward the outer circumferential surface of the inverting front cylinder 44 with a pressing roller (not shown).

[0028] The transport unit 20 has a second rotary motor 50 (see Figure 4) as a second drive source for rotating the inverting front cylinder 44, and the second rotary motor 50 is provided at an appropriate position on the center frame 14. With the tip of the recording medium P gripped and held by the multiple gripping claws 46 of the inverting front cylinder 44, the inverting front cylinder 44 is rotated by the drive of the second rotary motor 50, thereby transporting the recording medium P that has been printed on one side in the transport direction. The second rotary motor 50 corresponds to a speed adjustment unit that adjusts the rotation speed of the inverting front cylinder 44 in relation to the rotation speed of the printing cylinder 22.

[0029] As shown in Figure 1, the transport unit 20 has a reversing swing device 52 which is a reversing unit that transfers the recording medium P, which has been received from the reversing cylinder 44, to the printing cylinder 22 with its front and back sides reversed. The reversing swing device 52 is pivotably mounted between the reversing cylinder 44 and the printing cylinder 22 in the center frame 14.

[0030] The tip of the reversing swing device 52 is provided with multiple gripping claws 54 (only one gripping claw 54 is shown) that grip and hold the tip of the recording medium P. The multiple gripping claws 54 of the reversing swing device 52 are spaced apart in the transport width direction. By swinging the reversing swing device 52, the multiple gripping claws 54 move between a position corresponding to the front cylinder 44 (an approaching position) and a position corresponding to the printing cylinder 22.

[0031] After positioning the multiple gripping claws 54 of the reversing swing device 52 to correspond to the front reversing body 44, the multiple gripping claws 54 of the reversing swing device 52 and the multiple gripping claws 46 of the front reversing body 44 perform a gripping change operation of the recording medium P. The multiple gripping claws 54 of the reversing swing device 52 receive the rear end of the recording medium P from the front reversing body 44 as the front end of the recording medium P and hold it.

[0032] After positioning the multiple gripping claws 54 of the reversing swing device 52 to correspond to the printing cylinder 22, the multiple gripping claws 54 of the reversing swing device 52 and the multiple gripping claws 24 of any claw group 24G of the printing cylinder 22 perform a gripping change operation of the recording medium P. The multiple gripping claws 24 of any claw group 24G of the printing cylinder 22 receive and hold the leading edge of the recording medium P from the multiple gripping claws 54 of the reversing swing device 52. The gripping claws 54 are also referred to as holding claws that hold the leading edge of the recording medium P.

[0033] As described above, the transport unit 20 includes a printing cylinder 22, an upstream cylinder 28, a first downstream cylinder 32, a second downstream cylinder 36, a third downstream cylinder 40, a reversing cylinder 44, and a reversing swing device 52, etc. The transport unit 20 transports the recording medium P in the transport direction while gripping and holding the leading edge of the recording medium P with a plurality of gripping claws 24, etc. The transport unit 20 transports the recording medium P in the transport direction while performing gripping changes with the plurality of gripping claws 24, etc.

[0034] As shown in Figure 1, the inkjet printing apparatus 10 is equipped with a first loading section 56 for stacking multiple recording media P, and the first loading section 56 is provided on the first side frame 16. The first loading section 56 has a loading tray 58 for placing the recording media P, and the loading tray 58 is provided on the first side frame 16 so as to be able to move up and down. The loading tray 58 is configured to move up and down according to the amount of recording media P to be loaded, and the uppermost recording media P is held at a predetermined height position.

[0035] The inkjet printing apparatus 10 includes a feeder unit 60 that supplies the recording medium P transferred from the mounting tray 58 to the transport unit 20. The feeder unit 60 is provided extending from the first side frame 16 to the center frame 14. The feeder unit 60 is located between the printing cylinder 22 and the first loading unit 56. The feeder unit 60 has a plurality of rotatable support rollers 62 and an endless belt 64 that is wrapped around the plurality of support rollers 62. One of the support rollers 62 is linked to the output shaft of the rotary motor 26. In addition, a transport unit 66 is provided above the first loading unit 56 on the first side frame 16 for transferring the uppermost recording medium P loaded on the mounting tray 58 to the feeder unit 60.

[0036] As shown in Figures 1 to 3, a pivot shaft 68 extending in the transport width direction is rotatably mounted on the downstream end of the feeder section 60 in the center frame 14 via a pair of eccentric bearings 70. The pivot shaft 68 is configured to rotate in forward and reverse directions by a cam mechanism (not shown), and the cam mechanism is linked to the output shaft of a rotary motor 26. The pivot shaft 68 rotates in forward and reverse directions in conjunction with the rotation of the printing cylinder 22. The pair of eccentric bearings 70 are each rotatably supported on the center frame 14. Adjustment motors 72 are provided at appropriate positions on the center frame 14 to individually adjust the rotational position of the pair of eccentric bearings 70.

[0037] The base ends of multiple registration parts 74, which can contact the front end of the recording medium P, are integrally connected to the oscillating shaft 68. In other words, multiple registration parts 74 are provided on the downstream end of the feeder section 60 via the oscillating shaft 68 and a pair of eccentric bearings 70. The multiple registration parts 74 are arranged at intervals along the transport width direction. By rotating the oscillating shaft 68 in forward and reverse directions, the multiple registration parts 74 oscillate vertically around the oscillating shaft 68.

[0038] By individually adjusting the rotational position of each eccentric bearing 70 through the drive of each adjustment motor 72, the position of the oscillating shaft 68 in the transport direction and the inclination of the oscillating shaft 68 with respect to the transport width direction can be adjusted. In other words, the position of the multiple registration parts 74 in the transport direction and the inclination of the arrangement direction of the multiple registration parts 74 with respect to the transport width direction can be adjusted. The pair of adjustment motors 72 correspond to a registration adjustment unit that adjusts the position of the multiple registration parts 74 in the transport direction and the inclination of the arrangement direction of the multiple registration parts 74 with respect to the transport width direction.

[0039] The belt 64 is made to circulate by the rotation of multiple support rollers 62, thereby supplying the recording medium P transported by the transport unit 66 to the transport section 20. As a result, the recording medium P is positioned at a predetermined location on the feeder section 60 such that its leading edge contacts multiple registration sections 74 and becomes parallel to the transport width direction.

[0040] As shown in Figure 1, the inkjet printing apparatus 10 is equipped with a swing device 76 that transfers the recording medium P from the feeder section 60 to the upstream cylinder 28. The swing device 76 is pivotably mounted between the upstream cylinder 28 and the feeder section 60 in the center frame 14. The swing device 76 may also be considered as part of the transport section 20.

[0041] The tip of the swing device 76 is provided with multiple gripping claws 78 that hold and grip the tip of the recording medium P. The multiple gripping claws 78 of the swing device 76 are spaced apart in the direction of the transport width (see Figure 3). By swinging the swing device 76, the multiple gripping claws 78 move between a position corresponding to the downstream end of the feeder section 60 and a position corresponding to the upstream drum 28. The gripping claws 78 are also referred to as holding claws that hold the tip of the recording medium P.

[0042] After positioning the multiple gripping claws 78 of the swing device 76 to a position corresponding to the downstream end of the feeder section 60, the multiple gripping claws 78 of the swing device 76 grip and hold the tip of the recording medium P positioned at a predetermined position on the feeder section 60. Immediately after the multiple gripping claws 78 of the swing device 76 hold the tip of the recording medium P, the multiple registration sections 74 swing downward and move away from the recording medium P.

[0043] After positioning the multiple gripping claws 78 of the swing device 76 to correspond to the upstream body 28, the multiple gripping claws 78 of the swing device 76 and the multiple gripping claws 30 of the upstream body 28 perform a gripping change operation of the recording medium P while in close proximity to each other. The multiple gripping claws 30 of the upstream body 28 receive the tip of the recording medium P from the multiple gripping claws 78 of the swing device 76 and hold it.

[0044] As shown in Figure 1, the inkjet printing apparatus 10 includes a media heating unit 80 for heating the recording medium P supported on the printing cylinder 22. The media heating unit 80 is located on the downstream side of the upstream cylinder 28 in the center frame 14. The media heating unit 80 is positioned opposite the outer circumferential surface of the printing cylinder 22. The media heating unit 80 has, for example, an infrared heater and heats the printing cylinder 22 and the recording medium P so that the recording medium P being transported by the printing cylinder 22 reaches a temperature within a predetermined range.

[0045] As shown in Figure 1, the inkjet printing apparatus 10 includes a printing unit 82 that prints (forms an image) on the recording medium P while it is being transported. The printing unit 82 is located downstream of the media heating unit 80 in the center frame 14. The printing unit 82 is an image forming unit that forms an image on the recording medium P while it is being transported. The printing unit 82 has a plurality of inkjet units 84 that eject four colors of ink—yellow (Y), magenta (M), cyan (C), and black (K)—on the recording medium P supported on the printing cylinder 22. The plurality of inkjet units 84 corresponding to the four colors of ink—Y, M, C, and K—are arranged at intervals along the transport direction.

[0046] Each inkjet unit 84 has a plurality of inkjet heads (not shown) that eject ink onto the recording medium P, and each inkjet head has a plurality of nozzles (not shown) formed at its tip for ejecting ink. The plurality of inkjet heads are arranged, for example, in a staggered pattern along the transport width direction. In other words, each inkjet unit 84 constitutes a line head including a plurality of inkjet heads.

[0047] The ink ejected from the inkjet unit 84 is an ultraviolet-curable ink (UV ink) that hardens (solidifies) when irradiated with ultraviolet light, one of the energy rays. In particular, among UV inks, UV gel ink that changes phase between gel and sol (liquid) depending on the temperature is used. In addition to UV ink, other inks that have the property of drying or hardening when exposed to energy rays such as infrared rays or electron beams may be used as the ink ejected from the inkjet unit 84.

[0048] As shown in Figure 1, the inkjet printing apparatus 10 is equipped with an irradiation unit 86 that irradiates the recording medium P on which an image has been formed with ultraviolet light. The irradiation unit 86 is located downstream of the printing unit 82 in the center frame 14. The irradiation unit 86 is positioned opposite the outer circumferential surface of the printing cylinder 22. By irradiating the recording medium P with ultraviolet light from the irradiation unit 86, the ink on the recording medium P is cured, and the image can be fixed to the recording medium P. If a different ink is used as the ink ejected from the inkjet unit 84, the irradiation unit 86 irradiates with energy rays corresponding to the properties of the other ink.

[0049] As shown in Figure 1, the inkjet printing apparatus 10 includes an imaging unit 88 that captures images printed on the recording medium P. The imaging unit 88 is located downstream of the illumination unit 86 in the center frame 14. The imaging unit 88 is positioned opposite the outer circumferential surface of the printing cylinder 22. The imaging unit 88 is a camera in which multiple image sensors, such as multiple CCD (charge-coupled device) image sensors or multiple CMOS (Complementary Metal Oxide Semiconductor) image sensors, are arranged along the transport width direction. The imaging unit 88 can capture images 8,000 times over the entire area of ​​the recording medium P with a length of 800 mm, and has a resolution of 0.1 mm.

[0050] When printing on the surface Pa of the recording medium P, the imaging unit 88 images the multiple gripping claws 24 that are gripping and holding the front end of the recording medium P, and generates an image as shown in Figures 4A to 4D, for example. When printing on the back surface Pb of the recording medium P, the imaging unit 88 images the multiple gripping claws 24 that are gripping and holding the front end of the recording medium P, and generates an image as shown in Figures 5A and 5B, for example.

[0051] As shown in Figure 1, the inkjet printing apparatus 10 includes a delivery unit 90 for transporting the printed recording medium P fed from the third downstream cylinder 40. The delivery unit 90 is provided extending from the center frame 14 to the second side frame 18. The delivery unit 90 has a plurality of rotatable support rollers 92 and an endless belt 94 that is wrapped around the plurality of support rollers 92. In addition, one of the support rollers 92 is linked to the output shaft of a rotary motor 26. By rotating the belt 94 through the rotation of the plurality of support rollers 92, the printed recording medium P fed from the third downstream cylinder 40 is transported in the transport direction.

[0052] The inkjet printing apparatus 10 includes a second loading section 96 for loading multiple printed recording media P, and the second loading section 96 is provided on the second side frame 18. The second loading section 96 has a loading tray 98 for placing the printed recording media P. The second loading section 96 stores the recording media P until the user removes the recording media P from the loading tray 98.

[0053] Furthermore, the printing operations on one side and both sides of the recording medium P by the inkjet printing device 10 are publicly known, as shown in, for example, Japanese Patent Application Publication No. 2014-168962, so a detailed explanation will be omitted.

[0054] The control configuration of the inkjet printing apparatus 10 according to this embodiment will be described with reference to Figures 4A to 6. Figure 6 is a control block diagram of the inkjet printing apparatus 10 according to this embodiment.

[0055] As shown in Figure 6, the inkjet printing apparatus 10 includes a control unit 100 that controls the rotary motor 26, feeder unit 60, adjustment motor 72, media heating unit 80, printing unit 82, and irradiation unit 86, etc. The control unit 100 is responsible for controlling the entire inkjet printing apparatus 10. The control unit 100 has a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). A storage unit 102 and a communication unit 104 are connected to the control unit 100.

[0056] The CPU provides overall control over the operation of the inkjet printer 10. The CPU reads various control programs and setting data stored in ROM and stores them in RAM, then executes the programs to perform various calculations. RAM also provides the CPU with a working memory space and stores temporary data. RAM may include non-volatile memory.

[0057] When the CPU performs various calculations, it refers to various data stored in the memory unit 102. The memory unit 102 is composed of, for example, a non-volatile semiconductor memory or a hard disk drive.

[0058] The control unit 100 transmits and receives various data to and from external devices (e.g., personal computers) connected to a communication network such as a LAN (Local Area Network) or WAN (Wide Area Network) via the communication unit 104. For example, the control unit 100 receives a print job transmitted from an external device and controls the printing unit 82 based on the image data contained in the print job. The communication unit 104 is composed of a communication control card, such as a LAN card.

[0059] The control unit 100 functions as a gripping state acquisition unit 106, a determination unit 108, an adjustment control unit 110, and a notification unit 112 by executing various control programs. The contents of the gripping state acquisition unit 106, the determination unit 108, the adjustment control unit 110, and the notification unit 112 are as follows.

[0060] As shown in Figures 4A to 6, the gripping state acquisition unit 106 acquires the gripping state of the multiple gripping claws 24 with respect to the recording medium P based on the captured image generated by the imaging unit 88. When the gripping state acquisition unit 106 acquires the gripping state of the multiple gripping claws 24, well-known image processing techniques such as edge detection are used. The imaging unit 88 and the gripping state acquisition unit 106 correspond to a gripping state detection unit that detects the gripping state of the multiple gripping claws 24 with respect to the recording medium P.

[0061] When printing on the surface Pa of the recording medium P, the gripping state acquisition unit 106 acquires the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P based on the captured image generated by the imaging unit 88. In other words, the imaging unit 88 and the gripping state acquisition unit 106, acting as gripping state detection units, detect the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P when printing on the surface Pa of the recording medium P.

[0062] When printing on the back surface Pb of the recording medium P, the gripping state acquisition unit 106 acquires the gripping state of the multiple gripping claws 24 with respect to the back surface Pb of the recording medium P based on the captured image generated by the imaging unit 88. In other words, the imaging unit 88 and the gripping state acquisition unit 106, acting as gripping state detection units, detect the gripping state of the multiple gripping claws 24 with respect to the front surface Pa of the recording medium P when printing on the back surface Pb of the recording medium P.

[0063] Specifically, the gripping state acquisition unit 106 acquires the gripping amount of the multiple gripping claws 24 as the gripping state of the multiple gripping claws 24, based on the image captured from the imaging unit 88. In other words, the imaging unit 88, acting as a gripping state detection unit, and the gripping state acquisition unit 106 detect the gripping amount of the multiple gripping claws 24 as the gripping state of the multiple gripping claws 24.

[0064] The gripping state acquisition unit 106 acquires the difference between the maximum and minimum values ​​of the gripping amount of the multiple gripping claws 24 as the gripping state of the multiple gripping claws 24, based on the captured image generated by the imaging unit 88. In other words, the imaging unit 88, acting as a gripping state detection unit, and the gripping state acquisition unit 106 detect the difference between the maximum and minimum values ​​of the gripping amount of the multiple gripping claws 24 as the gripping state of the multiple gripping claws 24.

[0065] The gripping state acquisition unit 106 acquires the gripping state of the multiple gripping claws 24 based on the captured image generated by the imaging unit 88, by obtaining the distance from the side end of the gripping claws 24 located on the outside in the transport width direction to the side end of the recording medium P. In other words, the imaging unit 88 and the gripping state acquisition unit 106, acting as gripping state detection units, detect the distance from the side end of the gripping claws 24 located on the outside in the transport width direction to the side end of the recording medium P.

[0066] The determination unit 108 determines whether the gripping state of the multiple gripping claws 24 is in an appropriate gripping state based on the results obtained by the gripping state acquisition unit 106. If the gripping state of the multiple gripping claws 24 is in an appropriate gripping state, the determination unit 108 determines that there is no abnormality in the gripping state of the multiple gripping claws 24. If the gripping state of the multiple gripping claws 24 is not in an appropriate gripping state, the determination unit 108 determines that there is an abnormality in the gripping state of the multiple gripping claws 24.

[0067] In other words, the determination unit 108 determines whether or not there is an abnormality in the gripping state of the multiple gripping claws 24 based on the results obtained by the gripping state acquisition unit 106. The determination unit 108 determines whether or not there is an abnormality in the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P, or whether or not there is an abnormality in the gripping state of the multiple gripping claws 24 with respect to the back surface Pb of the recording medium P. Note that the results obtained by the gripping state acquisition unit 106 are equivalent to the detection results of the gripping state detection unit.

[0068] Specifically, the determination unit 108 determines whether the gripping amount of the multiple gripping claws 24, as obtained by the gripping state acquisition unit 106, is within a preset appropriate gripping amount range. For example, as shown in Figures 4A and 5A, if the gripping amount of the multiple gripping claws 24 is within the appropriate gripping amount range, the determination unit 108 determines that there is no abnormality in the gripping state of the multiple gripping claws 24. For example, as shown in Figures 4B and 5B, if the gripping amount of the multiple gripping claws 24 is outside the appropriate gripping amount range, the determination unit 108 determines that there is an abnormality in the gripping state of the multiple gripping claws 24. Here, the appropriate gripping amount range is, for example, 3 ± 1 mm.

[0069] The determination unit 108 determines whether the difference between the maximum and minimum gripping amounts of the multiple gripping claws 24, as obtained by the gripping state acquisition unit 106, is within a preset appropriate difference range. For example, as shown in Figure 4A, the determination unit 108 determines that there is no abnormality in the gripping state of the multiple gripping claws 24 if the difference is within the appropriate difference range. For example, as shown in Figure 4C, the determination unit 108 determines that there is an abnormality in the gripping state of the multiple gripping claws 24 if the difference is outside the appropriate difference range. Here, the appropriate difference range is, for example, 1 mm.

[0070] The determination unit 108 determines whether the distance from the side end of the gripping claws 24, which are positioned on the outside in the transport width direction, to the side end of the recording medium P, as obtained by the gripping state acquisition unit 106, is within a preset appropriate distance range. For example, as shown in Figure 4A, the determination unit 108 determines that there is no abnormality in the gripping state of the multiple gripping claws 24 if the distance is within the appropriate distance range. For example, as shown in Figure 4C, the determination unit 108 determines that there is an abnormality in the gripping state of the multiple gripping claws 24 if the distance is outside the appropriate distance range. Here, the appropriate distance range is, for example, 1 ± 0.5 mm.

[0071] When the adjustment control unit 110 determines that there is an abnormality in the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P, it controls the adjustment operation of each adjustment motor 72, which acts as a registration adjustment unit, as follows: Based on the results obtained by the gripping state acquisition unit 106, the adjustment control unit 110 controls the adjustment operation of the pair of adjustment motors 72 so that the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P becomes an appropriate gripping state.

[0072] If the adjustment control unit 110 determines that there is an abnormality in the gripping state of the multiple gripping claws 24 with respect to the back surface Pb of the recording medium P, it controls the adjustment operation of the second rotary motor 50 as follows: Based on the results obtained by the gripping state acquisition unit 106, the adjustment control unit 110 controls the adjustment operation of the second rotary motor 50 so that the gripping state of the multiple gripping claws 24 with respect to the back surface Pb of the recording medium P is in an appropriate gripping state. The adjustment control unit 110 controls the adjustment operation of the second rotary motor 50 on the condition that the adjustment operation of the pair of adjustment motors 72 has been performed.

[0073] If the adjustment control unit 110 determines that there is an abnormality in the gripping state of the multiple gripping claws 24 against the back surface Pb of the recording medium P, it may control the adjustment operation of the suction force adjustment unit 48 as follows: Based on the results obtained by the gripping state acquisition unit 106, the adjustment control unit 110 controls the suction force adjustment unit 48 so that the gripping state of the multiple gripping claws 24 against the back surface Pb of the recording medium P becomes an appropriate gripping state. The adjustment control unit 110 controls the adjustment operation of the suction force adjustment unit 48 on the condition that the adjustment operation of the pair of adjustment motors 72 has been performed.

[0074] The notification unit 112 notifies the user, for example, by displaying the result of an abnormality in the gripping state of the multiple gripping claws 24 on a display unit (not shown).

[0075] According to the configuration of the inkjet printing apparatus 10 of this embodiment, as described above, the imaging unit 88 and the gripping state acquisition unit 106, which act as gripping state detection units, detect the gripping state of the plurality of gripping claws 24 with respect to the recording medium P. The determination unit 108 determines whether or not there is an abnormality in the gripping state of the plurality of gripping claws 24 based on the acquisition result of the gripping state acquisition unit 106 (the detection result of the gripping state detection unit). Therefore, if the gripping state of the plurality of gripping claws 24 is not the proper gripping state, the determination unit 108 determines that there is an abnormality in the gripping state of the plurality of gripping claws 24, thereby preventing the state of improper gripping from continuing. In particular, the notification unit 112 notifies the determination result, which allows for quick avoidance of the state of improper gripping.

[0076] Therefore, according to the inkjet printing apparatus 10 of this embodiment, it is possible to suppress the detachment of the recording medium P from the printing cylinder 22 of the transport unit 20 while suppressing damage to the leading edge of the recording medium P.

[0077] Furthermore, according to the configuration of the inkjet printing apparatus 10 in this embodiment, as described above, the imaging unit 88 and the gripping state acquisition unit 106, which act as gripping state detection units, detect the gripping amount of the multiple gripping claws 24 as the gripping state of the multiple gripping claws 24. The determination unit 108 determines whether the difference between the maximum and minimum values ​​of the gripping amounts of the multiple gripping claws 24, which are the acquisition results of the gripping state acquisition unit 106 (detection results of the gripping state detection unit), is within an appropriate difference range. Therefore, the determination unit 108 can properly determine whether or not there is an abnormality in the gripping state of the multiple gripping claws 24.

[0078] According to the inkjet printing apparatus 10 of this embodiment, it is possible to efficiently determine whether or not there is an abnormality in the gripping state of the multiple gripping claws 24.

[0079] Furthermore, according to the configuration of the inkjet printing apparatus 10 in this embodiment, the imaging unit 88 and the gripping state acquisition unit 106, which act as gripping state detection units, detect the difference between the maximum and minimum values ​​of the gripping amount of the multiple gripping claws 24 as the gripping state of the multiple gripping claws 24. The determination unit 108 determines whether the difference between the maximum and minimum values ​​of the gripping amount of the multiple gripping claws 24, which is the acquisition result of the gripping state acquisition unit 106 (detection result of the gripping state detection unit), is within an appropriate difference range. Therefore, the determination unit 108 can properly determine whether or not there is an abnormality in the gripping state of the multiple gripping claws 24.

[0080] According to the inkjet printing apparatus 10 of this embodiment, it is possible to efficiently determine whether or not there is an abnormality in the gripping state of the multiple gripping claws 24.

[0081] Furthermore, according to the configuration of the inkjet printing apparatus 10 in this embodiment, the imaging unit 88 and the gripping state acquisition unit 106 detect the distance from the side end of the gripping claws 24, which are positioned on the outside in the transport width direction, to the side end of the recording medium P, as the gripping state of the plurality of gripping claws 24. The determination unit 108 determines whether the distance obtained by the gripping state acquisition unit 106 (detection result of the gripping state detection unit) is within an appropriate distance range. Therefore, the determination unit 108 can properly determine whether or not there is an abnormality in the gripping state of the plurality of gripping claws 24.

[0082] According to the inkjet printing apparatus 10 of this embodiment, it is possible to efficiently determine whether or not there is an abnormality in the gripping state of the multiple gripping claws 24.

[0083] According to the configuration of the inkjet printing apparatus 10 in this embodiment, the adjustment control unit 110 controls the adjustment operation of the pair of adjustment motors 72 as described above when it determines that there is an abnormality in the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P. Therefore, the gripping state of the multiple gripping claws 24 with respect to the surface Pa of the recording medium P can be automatically adjusted to an appropriate gripping state.

[0084] Therefore, the inkjet printing apparatus 10 according to this embodiment can enhance the utility of the inkjet printing apparatus 10.

[0085] According to the configuration of the inkjet printing apparatus 10 in this embodiment, the adjustment control unit 110 controls the adjustment operation of the second rotary motor 50 as described above when it determines that there is an abnormality in the gripping state of the multiple gripping claws 24 with respect to the back surface Pb of the recording medium P. Therefore, the gripping state of the multiple gripping claws 24 with respect to the back surface Pb of the recording medium P can be automatically adjusted to an appropriate gripping state.

[0086] Therefore, the inkjet printing apparatus 10 according to this embodiment can enhance the utility of the inkjet printing apparatus 10.

[0087] According to the configuration of the inkjet printing apparatus 10 in this embodiment, the adjustment control unit 110 controls the suction force adjustment unit 48 as described above when it determines that there is an abnormality in the gripping state of the plurality of gripping claws 24 with respect to the back surface Pb of the recording medium P. Therefore, the gripping state of the plurality of gripping claws 24 with respect to the back surface Pb of the recording medium P can be automatically adjusted to an appropriate gripping state.

[0088] Therefore, the inkjet printing apparatus 10 according to this embodiment can enhance the utility of the inkjet printing apparatus 10.

[0089] Although this embodiment has been described in detail above, the present invention is not limited to the specific embodiments described above. Within the scope of the gist of the present invention as described in the claims, various modifications and changes are possible to the specific examples described in the above embodiments. For example, instead of the imaging unit 88 and the gripping state acquisition unit 106, which act as gripping state detection units, detecting the gripping state of the plurality of gripping claws 24 on the recording medium P, the gripping state of any one of the plurality of gripping claws 24 may be detected. The technical ideas applied to the inkjet printing apparatus 10 may also be applied to printing apparatuses other than the inkjet printing apparatus 10, such as offset sheet-fed printing presses. [Industrial applicability]

[0090] The present invention is useful as a printing apparatus that can suppress damage to the leading edge of the recording medium while preventing the recording medium from falling out of the transport section. [Explanation of symbols]

[0091] 10. Inkjet printing device (printing device) 12 Printing device body 14 Center Frame 16. First side frame 18. Second side frame 20 Conveying section 22 Printing Cylinders 24. Claws 24G Nail Group 26 Rotary motor (drive source) 28 Upstream body 30 Gripping claws 32 First Downstream Drum 34. Claws 36. Second Downstream Drum 38. Claws 40 Third Downstream Drum 42. Claws 44 Reversible front fuselage 46. ​​Claws 48 Adsorption force adjustment part 50. Second rotation motor (speed adjustment unit) 52 Reversing swing device 54. Claws 56. First Loading Section 58 Mounting tray 60 Feeder section 62 Support rollers 64 belts 66 Transfer Unit 68. Oscillating axis 70 Eccentric bearing 72 Adjustment Motor 74. Registration Section 76 Swing device 78. Claws 80 Medium heating section 82 Printing Department 84 Inkjet Section 86 Irradiation area 88 Imaging Unit 90 Delivery Department 92 Support rollers 94 belt 96 Second Loading Section 98 Mounting tray 100 Control Unit 102 Storage section 104 Communications Department 106 Gripping state acquisition unit 108 Judgment section 110 Adjustment Control Unit 112 Hochi Department P recording medium

Claims

1. A transport unit that holds the tip of the recording medium with gripping claws and transports the recording medium in the transport direction, A printing unit that prints on the recording medium while it is being transported, A gripping state detection unit that detects the gripping state of the gripping claws on the recording medium, The system includes a determination unit that determines whether or not there is an abnormality in the gripping state of the gripping claws based on the detection result of the gripping state detection unit. Printing device.

2. The conveying unit has a plurality of gripping claws, and the plurality of gripping claws are arranged along the conveying width direction perpendicular to the conveying direction. The gripping state detection unit detects the gripping state of at least one of the plurality of gripping claws. The printing apparatus according to claim 1.

3. The gripping state detection unit detects the gripping amount of any of the gripping claws as the gripping state of any of the gripping claws, The determination unit determines whether the amount of gripping detected by the gripping state detection unit is within a preset appropriate range of gripping amounts. The printing apparatus according to claim 2.

4. The gripping state detection unit detects the difference between the maximum and minimum values ​​of the gripping amounts of the multiple gripping claws as the gripping state of any of the gripping claws. The determination unit determines whether the difference detected by the gripping state detection unit is within a preset appropriate difference range. The printing apparatus according to claim 2.

5. The gripping state detection unit detects the gripping state of any of the gripping claws by detecting the distance from the side end of the gripping claw located on the outside in the transport width direction among the plurality of gripping claws to the side end of the recording medium, The determination unit determines whether the distance detected by the gripping state detection unit is within a preset appropriate distance range. The printing apparatus according to claim 2.

6. A feeder unit that supplies recording media to the transport unit, A plurality of registration parts are provided on the downstream end side of the feeder section, arranged along the transport width direction perpendicular to the transport direction, and capable of contacting the leading edge of the recording medium, A registration adjustment unit that adjusts the position of the multiple registration units in the transport direction and / or the inclination of the arrangement direction of the multiple registration units with respect to the transport width direction, The device includes an adjustment control unit that, when it is determined that there is an abnormality in the gripping state of any of the gripping claws, controls the adjustment operation of the registration adjustment unit based on the detection result of the gripping state detection unit so that the gripping state of the plurality of gripping claws becomes an appropriate gripping state, The printing apparatus according to claim 2.

7. The transport unit has the gripping claws on its outer circumferential surface and a printing cylinder that rotates while carrying a recording medium. The printing apparatus according to claim 1.

8. The printing unit has an inkjet unit that ejects ink onto a recording medium while it is being transported to create an image. The printing apparatus according to claim 1.

9. The gripping state detection unit is, An imaging unit that captures an image of the gripping claws while they are gripping and holding the tip of the recording medium, and generates an image of the gripping claws. The device includes a gripping state acquisition unit that acquires the gripping state of the gripping claws based on the captured image generated by the imaging unit, The printing apparatus according to claim 1.

10. The imaging unit is a camera that reads an image printed on a recording medium. The printing apparatus according to claim 9.

11. The gripping state detection unit detects the state of any of the gripping claws relative to the surface of the recording medium when printing on the surface of the recording medium, and detects the state of any of the gripping claws relative to the surface of the recording medium when printing on the back surface of the recording medium. The determination unit determines, based on the detection result of the gripping state detection unit, whether or not there is an abnormality in the state of any of the gripping claws on the surface of the recording medium, and whether or not there is an abnormality in the state of any of the gripping claws on the back surface of the recording medium. The printing apparatus according to claim 2.

12. The aforementioned transport unit is A printing cylinder having multiple gripping claws on its outer circumferential surface and rotating while supporting a recording medium; and a reversing front cylinder positioned opposite the printing cylinder, having multiple gripping claws on its outer circumferential surface and rotating while supporting a recording medium received from the printing cylinder; The system includes a reversing unit positioned between the printing cylinder and the reversing cylinder, which receives the recording medium from the reversing cylinder and transfers the recording medium to the printing cylinder with its front and back sides reversed. The printing apparatus according to claim 11.

13. A feeder unit that supplies recording media to the transport unit, A plurality of registration parts are provided on the downstream end side of the feeder section, arranged along the transport width direction perpendicular to the transport direction, and capable of contacting the leading edge of the recording medium, A registration adjustment unit that adjusts the position of the multiple registration units in the transport direction and / or the inclination of the arrangement direction of the multiple registration units with respect to the transport width direction, The device includes an adjustment control unit that, when it is determined that there is an abnormality in the gripping state of any of the gripping claws with respect to the surface of the recording medium, controls the adjustment operation of the registration adjustment unit based on the detection result of the gripping state detection unit so that the gripping state of the plurality of gripping claws becomes an appropriate gripping state, The printing apparatus according to claim 12.

14. It is equipped with a speed adjustment unit that adjusts the rotation speed of the reversing cylinder in relation to the rotation speed of the printing cylinder, If the adjustment control unit determines that there is an abnormality in the gripping state of any of the gripping claws with respect to the back surface of the recording medium, it controls the adjustment operation of the speed adjustment unit based on the detection result of the gripping state detection unit so that the gripping state of the multiple gripping claws becomes an appropriate gripping state. The printing apparatus according to claim 13.

15. The adjustment control unit controls the adjustment operation of the speed adjustment unit, provided that it has controlled the adjustment operation of the registration adjustment unit. The printing apparatus according to claim 14.

16. The inverted front cylinder is equipped with a tension adjustment unit for adjusting the tension of the recording medium supported on its outer circumferential surface, If the adjustment control unit determines that there is an abnormality in the gripping state of any of the gripping claws with respect to the back surface of the recording medium, it controls the adjustment operation of the tension adjustment unit based on the detection result of the gripping state detection unit so that the gripping state of the multiple gripping claws becomes an appropriate gripping state. The printing apparatus according to claim 13.

17. The adjustment control unit controls the adjustment operation of the tension adjustment unit, provided that it has controlled the adjustment operation of the registration adjustment unit. The printing apparatus according to claim 16.

18. The device is equipped with a notification unit that notifies the result of a determination that there is an abnormality in the gripping state of the aforementioned gripping claws. The printing apparatus according to claim 1.

Images