Printing device

Abstract

A printing apparatus (1) is provided with a processing device (27), a processing cylinder (21) that conveys a sheet (4) to a position where printing is performed by the processing device (27), a pre-printing processing device (25) provided upstream of the processing cylinder (21), a pre-printing conveying device (16) that conveys the sheet (4) to a position where pre-printing processing is performed by the pre-printing processing device (25) and feeds the sheet (4) to the processing cylinder (21), a conveying mechanism (26) that feeds the printed sheet (4) to a device of a next step, a reversing cylinder (45) that reverses the front and back of the sheet (4) from the conveying mechanism (26), and a post-reversing conveying device (47) that conveys the sheet (4) that has been subjected to front and back reversal to the upstream side of the pre-printing processing device (25). According to this configuration, even on a sheet that has been subjected to front and back reversal, an appropriate amount of pre-printing processing can be performed.

Description

Technical Field

[0001] The present invention relates to a printing apparatus, comprising: a processing cylinder that holds and conveys a sheet; and a processing device for performing processing, including printing, on the sheet on the processing cylinder. Background Technology

[0002] Patent Document 1 discloses an example of a conventional printing apparatus including an inkjet head. The printing apparatus disclosed in Patent Document 1 includes a flipping and oscillating device for flipping the front and back sides of a printed sheet and returning it to the printing cylinder, thereby enabling printing on both sides of the sheet using the inkjet head. The flipping and oscillating device is configured to oscillate towards the printing cylinder while holding the sheet at its trailing edge on the upstream side along the sheet transport direction, and to transfer the sheet to a gripper device on the printing cylinder.

[0003] In this type of printing apparatus, the sheet to be printed can be pre-treated. To pre-treat the sheet, a pre-treatment device is installed upstream of the inkjet head along the sheet transport direction, and the sheet transported by the printing cylinder is pre-treated. In recent years, there has been a need to increase the number of processes in the pre-treatment stage to further improve print quality.

[0004] To pre-treat the sheet material fed by the printing cylinder, a pre-treatment unit must be installed in the space around the printing cylinder. However, increasing the number of processes in the pre-treatment process makes the pre-treatment unit larger, which leads to the problem that the pre-treatment unit cannot be positioned facing the printing cylinder. When printing on both sides of the sheet, it is also conceivable to pre-treat specifically for the front side or specifically for the back side, thus posing a risk of insufficient pre-treatment.

[0005] List of cited references

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 2017-210337

[0008] Patent Document 2: Japanese Patent No. 2013-240987

[0009] Patent Document 3: Japanese Patent No. H05-16330 Summary of the Invention

[0010] Technical issues

[0011] The purpose of this invention is to provide a printing apparatus that can perform just the right pre-printing treatment on a flipped sheet, without overdoing it or underdoing it.

[0012] Solution

[0013] One aspect of the present invention relates to a printing apparatus, comprising: a processing device configured to perform processing, including printing, on a sheet; a processing roller configured to convey the sheet to a position where it is processed by the processing device; a pre-printing processing device arranged upstream of the processing roller in the sheet conveying direction and configured to perform pre-printing processing on the sheet; a pre-printing conveying device configured to convey the sheet to the position where it is pre-printed by the pre-printing processing device and to convey the pre-printed sheet to the processing roller; a conveying mechanism configured to receive the sheet, which has undergone processing including printing, from the processing roller and to convey the sheet to a device for a next processing step; a flipping roller configured to receive the sheet from the conveying mechanism and flip the front and back sides of the sheet; and a post-flipping conveying mechanism configured to receive the flipped sheet from the flipping roller and to convey the sheet to the upstream side of the pre-printing processing device in the sheet conveying direction.

[0014] The printing apparatus may further include a feeding device comprising a feed plate configured to convey sheet material to a pre-printing conveyor. The pre-printing conveyor may include a supply roller configured to receive sheet material from the feed plate. A post-turnover conveyor mechanism may include a post-turnover conveyor configured to convey turned sheet material to the supply roller. The post-turnover conveyor may be a chain conveyor. The post-turnover conveyor may also be constructed using an odd number of conveyor rollers.

[0015] The aforementioned printing apparatus may further include a feeding device comprising a feeding plate configured to convey the sheet to a pre-printing processing device. A flipping conveyor mechanism may be configured to convey the flipped sheet to the feeding device.

[0016] The flipped conveyor can be configured to convey the flipped sheet to the feed plate.

[0017] The feed plate may include: a first feed plate; and a second feed plate, which is arranged downstream of and spaced apart from the first feed plate in the sheet conveying direction. The flip-over conveying mechanism may be configured to convey the sheet to the second feed plate from below the first and second feed plates through the gap between them.

[0018] The feed plate may include a pressing guide disposed above the gap between the first and second feed plates and configured to change the conveying direction of sheet material fed from below through the gap to a direction along the second feed plate. The feed plate may include an adsorption roller disposed above the gap between the first and second feed plates and configured to rotate while adsorbing sheet material arriving at the gap from below, thereby guiding the sheet material downstream of the second feed plate in the sheet conveying direction.

[0019] The flipping conveyor mechanism may include: a flipping conveyor configured to convey a sheet from a flipping roller; and a clamping conveyor belt configured to clamp the sheet conveyed by the flipping conveyor from both sides along its thickness direction and convey the sheet to the gap between a first feed plate and a second feed plate. The flipping conveyor may be constructed using a chain conveyor. The flipping conveyor may also be constructed using an odd number of conveyor rollers.

[0020] The tilting roller may include a gripping member configured to grip the trailing edge of the sheet on its upstream side along the sheet conveying direction. The gripping member may be configured to pivot relative to the tilting roller about an axis parallel to the axis of the tilting roller.

[0021] Beneficial effects of the present invention

[0022] In one aspect of the invention, the pre-printing treatment apparatus is installed at a position spaced upstream of the processing cylinder along the sheet conveying direction. Therefore, the number of processes in the pre-printing treatment performed by the pre-printing treatment apparatus can be easily increased. Furthermore, the flipped sheet is pre-treated on its back side by the pre-printing treatment apparatus and then conveyed to the processing cylinder, where the back side is printed. Thus, according to one aspect of the invention, a printing apparatus can be provided that is capable of performing just the right amount of pre-printing treatment on the flipped sheet, without over- or under-treatment. Attached Figure Description

[0023] Figure 1 A side view of a printing apparatus according to a first embodiment of the present invention is shown.

[0024] Figure 2 It shows Figure 1 A side view of the main part of the printing apparatus shown.

[0025] Figures 3A to 3C A schematic diagram illustrating the operation of the rotating drum is shown.

[0026] Figure 4 A side view of a printing apparatus according to a second embodiment of the present invention is shown. Detailed Implementation

[0027] First Embodiment

[0028] Reference Figure 1 , Figure 2 as well as Figures 3A to 3C A printing apparatus according to a first embodiment of the present invention is described.

[0029] exist Figure 1 The printing apparatus 1 shown in the figure will transfer the sheet 4 from the location located Figure 1 The rightmost feeding unit 2 conveys the material to the printing unit 3, where one or both sides of the sheet 4 are printed. After printing in the printing unit 3, the sheet 4 is sent to the delivery unit 5 and stacked in the delivery stack 6.

[0030] The feeding unit 2 (feeding device) includes: a feeding stack 11 in which a large number of sheets 4 are stacked; a suction nozzle 12 that picks up the uppermost sheet 4 from the sheets 4 on the feeding stack 11; and a feeding plate 13 that delivers the sheet 4 picked up by the suction nozzle 12 to the supply roller 17 of the pre-printing conveying device 16 of the printing unit 3, which will be described later.

[0031] The nozzle 12 is connected to the intermittent feed valve 14 and operates in either continuous or intermittent feeding mode of the sheet 4. When printing is performed only on the front side of the sheet 4, the nozzle 12 continuously feeds the sheet 4 to the feed plate 13. At the same time, when printing is performed on both the front and back sides of the sheet 4, the nozzle 12 intermittently feeds the sheet 4 to the feed plate 13.

[0032] The feed plate 13 conveys the sheet 4 via a rotating conveyor belt (not shown). The conveyor belt is wound between a drive pulley (not shown) and a driven pulley (not shown). A front guide (not shown) is provided near the downstream end of the feed plate 13 in the sheet conveying direction. The front guide is used to align the sheet 4 in the conveying direction. Side guides (not shown) are provided on both sides of the front guide for adjusting the alignment of the sheet 4 in the width direction.

[0033] A swing device 15 is provided between the feed plate 13 and the pre-printing conveyor 16 to convey the sheet 4 fed by the feed plate 13 to the supply roller 17 of the pre-printing conveyor 16 of the printing unit 3.

[0034] The printing unit 3 includes: a processing device 27 for processing the sheet 4, including printing; a processing roller 21 for adsorbing and conveying the sheet 4 to the position where it is processed by the processing device 27; a first pre-printing processing device 25 arranged upstream of the processing roller 21 in the sheet conveying direction for pre-printing processing of the sheet 4; a pre-printing conveying device 16 for conveying the sheet 4 to the position where it is pre-printed by the first pre-printing processing device 25 and for conveying the pre-printed sheet 4 to the processing roller 21; and a conveying mechanism 26 for receiving the sheet 4, which has been processed by the processing device 27 including printing, from the processing roller 21 and for conveying it to a device for the next processing.

[0035] The pre-printing conveying device 16 has a configuration for conveying the sheet 4 to the processing roller 21 using a supply roller 17, a first transfer roller 18, and a second transfer roller 19. The supply roller 17, the first transfer roller 18, and the second transfer roller 19 are respectively equipped with gripper devices 22, 23, and 24 (see...). Figure 2 The sheet 4 is conveyed to / from adjacent rollers using gripper devices 22 to 24. Gripper devices 22 to 24 grip and hold the leading edge 4a, which is the downstream end of the sheet 4 in the sheet conveying direction.

[0036] Of the three rollers in the pre-printing conveyor 16, the first pre-printing treatment device 25 is installed near the central first conveyor roller 18. The first pre-printing treatment device 25 consists of apparatus for surface treatment, printing, etc., of the sheet 4 before printing, such as a pre-coating device, a corona treatment device, a spot color printing device, and a spot color drying lamp, although not shown in detail. The pre-coating device is used to apply a coating to the sheet 4 before printing. The corona treatment device is used to perform corona discharge treatment on the sheet 4 before printing. The spot color printing device is used to perform spot color printing such as gold or silver. The spot color drying lamp is used to dry the ink printed by the spot color printing device. The pre-printing conveyor 16 conveys the pre-printing treated sheet 4 to the treatment roller 21 at the supply position P1.

[0037] The processing roller 21 is a three-diameter roller with a diameter three times that of a single roller, and as... Figure 2 As shown, a conveying surface 21a has three portions in the rotational direction that hold the sheet 4. The three conveying surfaces 21a are formed by the outer peripheral surface of the processing roller 21, and when viewed from the axial direction of the processing roller 21, the outer peripheral surface is divided into three equal parts in the rotational direction. An outer peripheral cutout 28 is provided between adjacent conveying surfaces 21a. A gripper device 29 is provided in the outer peripheral cutout 28. The gripper device 29 corresponds to the gripper devices 22 to 24 provided in the aforementioned supply roller 17, first transfer roller 18, and second transfer roller 19.

[0038] Near the circumference of the processing roller 21, a second pre-printing treatment device 36, first, second, third, and fourth inkjet heads 31, 32, 33, and 34, and an ink drying lamp 35 are arranged in sequence. The second pre-printing treatment device 36 performs a process that is the same as or different from the pre-printing treatment performed by the first pre-printing treatment device 25.

[0039] The first to fourth inkjet heads 31 to 34 perform printing by ejecting ink droplets onto the sheet 4. Each of the first to fourth inkjet heads 31 to 34 is provided with multiple nozzles (although not shown), which are aligned along the axial direction of the processing roller 21. Figure 2 The inkjet heads 31 to 34 are arranged perpendicular to the paper surface. Each of the first to fourth inkjet heads is provided with a heater (not shown) for heating the ink to a predetermined temperature so that the ink droplets adhere properly to the sheet 4.

[0040] The ink drying lamp 35 is used to cure the ink applied to the sheet 4 by the first to fourth inkjet heads 31 to 34. The ink drying lamp 35 irradiates the sheet 4 with infrared or ultraviolet light. The ink is dried or cured by being irradiated with infrared or ultraviolet light.

[0041] In this embodiment, the second pre-printing treatment device 36, the first to fourth inkjet heads 31 to 34, and the ink drying lamp 35 constitute the processing device 27, which is used to perform processing, including printing, on the sheet 4 on the processing roller 21. It should be noted that the second pre-printing treatment device 36 and the ink drying lamp 35 are not essential.

[0042] The conveying mechanism 26 includes: an exhaust roller 41 for receiving sheet 4 from the processing roller 21 at a receiving position P2 located downstream of the first to fourth inkjet heads 31 to 34 in the sheet conveying direction; and a double-diameter roller 42 for receiving sheet 4 from the exhaust roller 41. The exhaust roller 41 and the double-diameter roller 42 are respectively provided with gripper devices 43 and 44 for conveying sheet 4 (see [link to relevant documentation]). Figure 2 These gripper devices 43 and 44 correspond to gripper devices 22 to 24 disposed in the aforementioned supply roller 17, first conveyor roller 18 and second conveyor roller 19.

[0043] Among the sheets 4 received by the discharge roller 41 at the receiving position P2, the sheets 4 to which printing is to be performed on the back side are returned to the supply roller 17 in a flipped state via a flipping path 47 consisting of the discharge roller 41, the double-diameter roller 42 before flipping, the flipping roller 45 (described later), and the flipping conveyor 46. Meanwhile, the sheets 4 with printing only on the front side or with printing on both the front and back sides are discharged from the discharge roller 41 to the delivery unit 5 via a discharge path 49 including the conveyor belt 48.

[0044] The discharge roller 41 constitutes a sheet path distribution device, which distributes the conveying path as either a flipping path 47 for flipping the sheet 4 or a discharge path 49 for discharging the sheet 4. This sheet path distribution device can be configured using, for example, the technology disclosed in Patent Document 2. Patent Document 2 discloses a cam device that changes the opening and closing timing (sheet 4 conveying timing) of the gripper device 43 by using a cam that opens and closes the gripper device 43 of the discharge roller 41. This cam device is configured such that the sheet 4 is conveyed from the discharge roller 41 to either the gripper device 44 of the double-diameter roller 42 before flipping or a gripper device (not shown) that moves with the conveyor belt 48.

[0045] The delivery unit 5 has three functions. The first function is to stack the printed sheets 4 from the conveying mechanism 26 into the delivery stack 6. The second function is to extract samples. The third function is to transport the sheets 4 to the next process.

[0046] The flipping roller 45 rotates synchronously with the rollers 41 and 42 constituting the conveying mechanism 26, receives the sheet 4 from the conveying mechanism 26, flips the front and back sides of the sheet 4, and sends the flipped sheet 4 to the flipped conveying device 46. The flipping roller 45 is, for example, equivalent to the steering roller disclosed in Patent Document 3, and as... Figures 3A-3C As shown, it includes a gripping member 51 that grips the trailing edge 4b ​​of the sheet 4, which is located upstream in the conveying direction, as conveyed by the double-diameter roller 42 before tipping. The gripping member 51 is pivotable relative to the tipping roller 45 about an axis parallel to the axis of the tipping roller 45.

[0047] The flipping conveyor 46 transports the sheet 4 received from the flipping roller 45 to the supply roller 17. The flipping conveyor 46 is a chain conveyor and includes: a pair of chains 46a arranged in the axial direction of the flipping roller 45; a plurality of gripper bars (not shown) mounted between the chains 46a; and gripper devices (not shown) disposed on each of these gripper bars. The chains 46a are arranged between the flipping roller 45 and the supply roller 17. The flipping conveyor 46 may also be provided to use an odd number of transfer rollers instead of the chain conveyor (not shown). These transfer rollers are similar to the supply roller 17, the first transfer roller 18, the second transfer roller 19, etc., and are equipped with gripper devices for conveying and transporting the sheet 4.

[0048] The supply roller 17 forms the upstream end of the pre-printing conveyor 16 along the sheet conveying direction. Therefore, in this embodiment, the flipping conveyor 46 for conveying the sheet 4 to the supply roller 17 forms a flipping conveyor mechanism that receives the flipped sheet 4 from the flipping roller 45 and conveys it to the upstream side of the pre-printing conveyor 16 along the sheet conveying direction.

[0049] Reference Figures 3A-3C Describes the flipping of sheet 4. Sheet 4 is conveyed by double-diameter roller 42 before flipping, with the printed front side 4c exposed to the outside of the double-diameter roller 42. (As...) Figure 3A As shown, when the trailing edge 4b ​​of the sheet 4 passes between the double-diameter roller 42 and the flipping roller 45, the gripping member 51 of the flipping roller 45 grips and holds the trailing edge 4b ​​of the sheet 4. In this state, as the flipping roller 45 rotates, as... Figures 3B-3C As shown, sheet 4 is wound on a tilting roller 45, with the trailing edge 4b ​​located downstream along the conveying direction. Sheet 4 is conveyed as is from the tilting roller 45 to a tilting conveyor 46, and then returned from the tilting conveyor 46 to the supply roller 17.

[0050] When the sheet 4 is conveyed by the supply roller 17, the front side 4c of the sheet 4 is exposed to the outside of the supply roller 17. Therefore, the sheet 4 conveyed by the flipping path 47 is transferred from the supply roller 17 to the first transfer roller 18 in a flipped state, and while being conveyed by the first transfer roller 18, the back side of the sheet 4 is subjected to pre-printing treatment by the first pre-printing treatment device 25.

[0051] In the printing apparatus 1 constructed in this manner, since the first pre-printing treatment unit 25 is installed at a position spaced upstream of the processing roller 21 along the sheet conveying direction, space constraints are alleviated, and the number of processes in the pre-printing treatment performed by the first pre-printing treatment unit 25 can be easily increased. Furthermore, the flipped sheet 4 is pre-treated on its back side by the first pre-printing treatment unit and then conveyed to the processing roller 21 for printing. Therefore, according to this embodiment, a printing apparatus can be provided that can perform just the right amount of pre-printing treatment on the flipped sheet 4, without over- or under-processing.

[0052] In this embodiment, the printing apparatus 1 includes a feeding unit 2 that supplies sheet 4 via a feed plate 13. The upstream end of the pre-printing conveying device 16 along the conveying direction is constituted by a supply roller 17 for receiving the sheet 4 fed by the feed plate 13. The upstream side of the first pre-printing processing device 25, to which the flipped sheet 4 is conveyed, also becomes the supply roller 17. Therefore, pre-printing processing is performed on the back side of the sheet 4 by the first pre-printing processing device 25 in the same manner as on the front side.

[0053] Second Embodiment

[0054] The printing apparatus 1 described above employs a configuration that returns the flipped sheet 4 to the supply roller 17. However, in order for the first pre-printing processing unit 25 to pre-process the flipped sheet 4, the flipped sheet 4 can also be returned to the feeding unit 2, such as... Figure 4 As shown. In Figure 4 In, with Figures 1 to 3C Elements that are the same or equivalent as those shown are indicated by the same reference numerals, and their detailed descriptions are omitted.

[0055] exist Figure 4 The feeding unit 2 of the printing apparatus 61 shown is configured to supply sheet 4 from below to the middle of the feeding plate 13. The feeding plate 13 consists of a first feeding plate 13a and a second feeding plate 13b, with the second feeding plate 13b arranged downstream of the first feeding plate 13a in the sheet conveying direction and spaced apart from it. The gap between the first feeding plate 13a and the second feeding plate 13b forms a dividing portion 62 that divides the feeding plate 13 into an upstream side and a downstream side in the sheet conveying direction.

[0056] A pressing guide 63 and an adsorption roller 64 are provided above the dividing section 62. The pressing guide 63 changes the conveying direction of the sheet 4 fed from below through the dividing section 62 to the direction along the feed plate 13 (especially the second feed plate 13b). The adsorption roller 64 is driven to rotate while adsorbing the sheet 4 fed from below near the dividing section 62, and guides the sheet 4 downstream of the feed plate 13 (especially the second feed plate 13b) along the sheet conveying direction.

[0057] Below the dividing section 62, there is a pair of clamping conveyor belts 65 and 66 and the downstream end of the flipping conveyor 46 along the sheet conveying direction. The pair of clamping conveyor belts 65 and 66 rotate in opposite directions to each other, clamp the sheet 4 from both sides along the thickness direction, and convey the sheet 4 from the end of the flipping conveyor 46 to the dividing section 62.

[0058] In the printing apparatus 61 of this embodiment, the sheet 4, after being flipped by the flipping roller 45, is chain-conveyed by the flipping conveyor 46 and fed from the downstream end of the flipping conveyor 46 along the conveying direction between the pair of clamping conveyor belts 65, 66. The sheet 4 inserted between the clamping conveyor belts 65, 66 is clamped by the rotating clamping conveyor belts 65, 66 and conveyed to the dividing section 62. The sheet 4 arriving at the dividing section 62 is guided into the second feed plate 13b by the pressing guide 63 and the suction roller 64.

[0059] Similarly, in this embodiment, although not shown, a alignment device such as a front guide and a side guide is provided on the downstream side of the feed plate 13 (second feed plate 13b) along the sheet conveying direction. Therefore, the sheet 4 delivered to the downstream end of the feed plate 13 along the sheet conveying direction is supplied from the oscillating device 15 to the supply roller 17 in an alignment-adjusted state.

[0060] Therefore, in this embodiment, the flipped sheet 4 can also be subjected to just the right pre-printing treatment, without being excessive or insufficient.

[0061] In this embodiment, a flipped conveyor 46 for conveying the flipped sheet 4 from the flipping roller 45, and clamping conveyor belts 65 and 66 for clamping the sheet 4 conveyed by the flipped conveyor 46 from both sides along its thickness direction and conveying the sheet to the dividing section 62 constitute a flipped conveyor mechanism for conveying the sheet 4 from the flipping roller 45 to the feeding plate 13 of the feeding unit 2.

[0062] List of reference numerals

[0063] 1.61: Conveying device

[0064] 2: Feeding unit (feeding device)

[0065] 4: Sheets

[0066] 13: Feeder plate

[0067] 16: Pre-printing conveyor

[0068] 17: Supply Roller

[0069] 21: Processing rollers

[0070] 25: First pre-printing treatment unit (pre-printing treatment device)

[0071] 26: Conveying mechanism

[0072] 27: Processing device

[0073] 45: Tilting Roller

Claims

1. A printing apparatus, comprising: A processing apparatus configured to perform processing, including printing, on a sheet; A processing roller, configured to convey the sheet to a position where processing is performed by a processing device; A pre-printing treatment apparatus is arranged upstream of a treatment cylinder in the sheet conveying direction and is configured to perform pre-printing treatment on the sheet. A pre-printing conveyor, configured to convey sheet material to a position where pre-printing processing is performed by a pre-printing processing device, and to send the pre-printed sheet material to a processing roller. A conveying mechanism configured to receive sheet material from a processing roller after processing, including printing, by a processing device, and to convey the sheet material to a device for the next processing step. A flipping roller is configured to receive a sheet from a conveying mechanism and flip the front and back sides of the sheet. as well as A flip-over conveyor mechanism is configured to receive flipped sheets from a flip-over roller and convey the sheets to the upstream side of the pre-printing processing unit in the sheet conveying direction.

2. The printing apparatus according to claim 1, further comprising a feeding device, the feeding device including a feeding plate configured to feed the sheet to a pre-printing conveying device, wherein, The pre-printing conveying device includes a feed roller configured to receive sheets from a feed plate; and The flipped conveyor mechanism includes a flipped conveyor device configured to convey the flipped sheet to a supply roller.

3. The printing apparatus according to claim 1, further comprising a feeding device, the feeding device including a feeding plate configured to feed the sheet to a pre-printing treatment device, wherein, The flipped conveyor mechanism is configured to convey the flipped sheet to the feeding device.

4. The printing apparatus according to claim 3, wherein, The flipped conveyor is configured to convey the flipped sheet to the feed plate.

5. The printing apparatus according to claim 4, wherein, The feed plate includes a first feed plate and a second feed plate, wherein the second feed plate is arranged downstream of the first feed plate in the sheet conveying direction and is spaced apart from the first feed plate; and The flipped conveyor is configured to feed the sheet from below the first and second feed plates through the gap between the first and second feed plates.

6. The printing apparatus according to any one of claims 1 to 5, wherein, The tilting roller includes a gripping member configured to grip the tail edge of the sheet located on the upstream side along the sheet conveying direction; and The gripping member is configured to pivot relative to the tilting roller about an axis parallel to the axis of the tilting roller.

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