Inkjet recording device

Abstract

To provide an inkjet recording device capable of adjusting a height of a belt and a belt for delivering sheets between housings.SOLUTION: In the inkjet recording device, in order to match a height of a downstream end of a sheet transport surface 2201P with a height of an upstream side of a sheet transport surface 3201P, a first adjustment mechanism 3A capable of adjusting the height of the upstream side of the sheet transport surface 3201P is provided in a drying module 3000. In the first adjustment mechanism 3A, an upstream adjustment cam 311 is rotated in response to an adjustment dial being rotated by an external force. The upstream adjustment cam 311 is an eccentric cam, and abuts against a guard plate 3205 of the decoupling belt unit 3200. Therefore, when the upstream side adjusting cam 311 is rotated, an upstream side of the decoupling belt unit 3200 is lifted. In this manner, the height of the upstream side of the sheet conveying surface 3201P in the drying module 3000 is changed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an inkjet recording apparatus that forms an image with ink on a sheet transported on a belt. [Background technology]

[0002] Conventionally, there is known an inkjet recording device that forms an image on a sheet using ink. In the inkjet recording device, an image is formed on a sheet through an image forming process in which ink is ejected onto the sheet to form an image, a drying process in which the ink on the sheet is dried, and a fixing process in which the ink is fixed onto the sheet (Patent Document 1).

[0003] In recent years, industrial inkjet recording devices have been used to achieve high image quality and high productivity in the digital commercial printing market. In an industrial inkjet recording device, a print module that performs the image formation process, a drying module that performs the drying process, and a fixing module that performs the fixing process are provided in separate housings, and the inkjet recording device is assembled by connecting each housing that has been transported to the installation site. In order to enable the transfer of sheets between the housings, the heights of the respective housings are changed and the devices are connected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-170447 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the inkjet recording device described above, the sheet is transferred between the housings. In each module, the sheet is supported and transported by a belt rotatably provided on the housing. Therefore, if the height of the downstream side of the sheet transport surface of the belt provided on the upstream housing in the sheet transport direction does not match the height of the upstream side of the sheet transport surface of the belt provided on the downstream housing, it becomes difficult to transfer the sheet, which may cause transport problems.

[0006] However, in the past, even if the heights of the housings were adjusted, there was a risk that the heights of the belts would not match due to component tolerances, etc. This was particularly noticeable between the housings of a print module and a drying module. Therefore, in an inkjet recording device in which multiple housings are connected, a device that can adjust the heights of the belts to transfer sheets between the housings has been desired for a long time, but such a device has not yet been provided.

[0007] The present invention has been made in consideration of the above problems, and aims to provide an inkjet recording device in which the height of the belts that transfer sheets between multiple connected housings can be adjusted. [Means for solving the problem]

[0008] An inkjet recording device according to an embodiment of the present invention is an inkjet recording device that forms an image on a sheet with ink, and includes a first transport unit having an endless first belt that transports a sheet, a recording unit that ejects ink onto the sheet transported by the first belt to form an image, a first housing that houses the first transport unit and the recording unit, a second housing that is disposed downstream of the first housing in the sheet transport direction and connected to the first housing, an endless second belt that is housed in the second housing and transports the sheet delivered by the first belt, a first roller that stretches the second belt, and a second roller that is disposed upstream of the first roller in the transport direction and stretches the second belt. the sheet conveying surface is a sheet conveying surface between the first roller and the second roller, and a sheet conveying surface on the second belt is a sheet conveying surface on which the sheet is conveyed. The sheet conveying surface is a sheet conveying surface on which the sheet conveying surface ... Effect of the Invention

[0009] According to the present invention, in an inkjet recording apparatus in which a first housing and a second housing are connected, the heights of the first belt and the second belt that transfer the sheet between these housings can be aligned. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating an inkjet recording apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a printing module and a drying module. [Diagram 3] FIG. 4 is a perspective view showing a decoupling belt unit. [Figure 4] FIG. 13 is a schematic diagram showing a decoupling belt unit provided with a second adjustment mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Inkjet recording device> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, an outline of an inkjet recording apparatus of this embodiment will be described with reference to FIG. 1. The inkjet recording apparatus 100 shown in FIG. 1 is a so-called sheet-fed inkjet recording apparatus that forms an image on a sheet S using ink and a reaction liquid. The sheet S may be any recording material that can receive ink, such as paper such as plain paper or cardboard, plastic film such as an overhead projector sheet, a sheet of a special shape such as an envelope or index paper, or cloth.

[0012] In this specification, the side on which an operator stands when operating the inkjet recording apparatus 100 is referred to as the "front (or front)" and the opposite side is referred to as the "rear (or rear)". Additionally, the left side as viewed from the front is referred to as the "left" and the right side as viewed from the front is referred to as the "right".

[0013] 1, the inkjet recording apparatus 100 includes a feeding module 1000, a print module 2000, a drying module 3000, a fixing module 4000, a cooling module 5000, an inverting module 6000, and a stacking module 7000. The sheet S supplied from the feeding module 1000 is subjected to various processes while being transported along a transport path in each module, and is finally discharged to the stacking module 7000.

[0014] The feeding module 1000 , the printing module 2000 , the drying module 3000 , the fixing module 4000 , the cooling module 5000 , the reversing module 6000 and the stacking module 7000 each have a separate housing, and these housings are connected to constitute the inkjet recording apparatus 100 .

[0015] The feeding module 1000 has storage chambers 1500a, 1500b, and 1500c for storing sheets S, and the storage chambers 1500a to 1500c are provided so as to be able to be pulled out to the front side in order to store the sheets S. The sheets S are fed one by one in each of the storage chambers 1500a to 1500c by a separation belt and a transport roller, and are transported to the print module 2000. The number of storage chambers 1500a to 1500c is not limited to three, and one, two, or four or more may be provided.

[0016] The print module 2000 has a pre-imaging transport unit (not shown), a print belt unit 2200, and a recording unit 2300. The sheet S transported from the feeding module 1000 has its inclination and position corrected by the pre-imaging transport unit, and is transported to the print belt unit 2200. The recording unit 2300 is disposed at a position facing the print belt unit 2200 with respect to the transport path. The recording unit 2300 forms an image on the sheet S by ejecting ink from above onto the transported sheet S using a recording head (not shown). Details of the print module 2000 will be described later (see FIG. 2).

[0017] The drying module 3000 has a cold air blowing unit 3100, a decoupling belt unit 3200, a drying belt unit 3300, and a hot air blowing unit 3400. The drying module 3000 reduces the liquid content of the ink applied to the sheet S in order to improve the fixation of the ink to the sheet S by the subsequent fixing module 4000. The details of the drying module 3000 will be described later (see FIG. 2).

[0018] The fixing module 4000 has a fixing belt unit 4100. The fixing belt unit 4100 fixes the ink onto the sheet S by passing the sheet S conveyed from the drying module 3000 between a heated upper belt unit 4110 and a lower belt unit 4120.

[0019] The cooling module 5000 has a cooling section 5100, and cools the high-temperature sheet S transported from the fixing module 4000. The cooling section 5100 cools the sheet S, for example, by taking in outside air with a fan into a cooling box to increase the pressure inside the cooling box, and blowing air from nozzles formed in a transport guide onto the sheet S. The cooling sections 5100 are disposed on both sides of the transport path of the sheet S, and can cool the sheet S from both sides.

[0020] The cooling module 5000 is also provided with a transport path switching unit 5002. The transport path switching unit 5002 switches the transport path of the sheet S depending on whether the sheet S is transported to the reversing module 6000 or to a double-sided transport path for double-sided printing in which images are formed on both sides of the sheet S.

[0021] The inversion module 6000 has an inversion section 6400. The inversion section 6400 inverts the sheet S being conveyed, and changes the orientation of the sheet S when it is discharged to the stacking module 7000. The stacking module 7000 has a top tray 7200 and a stacking section 7500, and stacks the sheet S conveyed from the inversion module 6000.

[0022] During double-sided printing, the sheet S is conveyed to a conveyance path below the cooling module 5000 by the conveyance path switching unit 5002. Thereafter, the sheet S passes through a double-sided conveyance path of the fixing module 4000, the drying module 3000, the print module 2000, and the feeding module 1000, and is returned to the print module 2000. The double-sided conveyance section of the fixing module 4000 is provided with an inversion unit 4200 that inverts the sheet S. The sheet S returned to the print module 2000 has an image formed with ink on the other side on which the image is not formed, and is discharged to the stacking module 7000 via the drying module 3000, the fixing module 4000, the cooling module 5000, and the inversion module 6000.

[0023] <Print module> Next, the print module 2000 will be described with reference to Fig. 2. As shown in Fig. 2, the print module 2000 has a print belt unit 2200 and a recording unit 2300, which are housed in a housing 200 serving as a first housing. An openable front cover 201 is provided on the front of the housing 200, and an operator can perform maintenance or replacement of the print belt unit 2200 or the recording unit 2300 by opening the front cover 201 as necessary.

[0024] A side cover 202 is provided on the side of the housing 200 facing the drying module 3000, and a discharge port 202a is formed in the side cover 202 for discharging the sheet S from the print module 2000 to the drying module 3000. Height-adjustable legs 210 are provided at each of the four corners on the bottom of the housing 200, and the housing 200 is moved up and down according to the height adjustment of these legs 210. This changes the heights of the print belt unit 2200, the recording unit 2300, and even the discharge port 202a from the installation surface.

[0025] A recording unit 2300 is disposed at a position facing the print belt unit 2200 with respect to the transport path of the sheet S. The recording unit 2300 forms an image by ejecting ink onto the transported sheet S from above using multiple recording heads. The sheet S is transported by suction using the print belt unit 2200, thereby ensuring clearance with the recording heads. In this embodiment, a total of five line-type recording heads corresponding to four colors, Y (yellow), M (magenta), C (cyan), and Bk (black), and reaction liquids, are aligned along the transport direction of the sheet S (direction of the arrow X).

[0026] The sheet S is conveyed by a print belt unit 2200 as a first conveying unit. The print belt unit 2200 has an endless print belt 2201, a plurality of tension rollers 2270a, 2270b, 2270c, and 2270d that rotatably suspend the print belt 2201, and a suction unit 2260. At least one of the tension rollers 2270a, 2270b, 2270c, and 2270d is a drive roller that drives the print belt 2201 to rotate.

[0027] The print belt 2201 as a first belt is disposed vertically below the recording unit 2300 and rotates to transport the sheet S. In the rotation direction of the print belt 2201, both sides of a sheet transport surface 2201P that transports the sheet S are stretched by a pair of tension rollers 2270a and 2270b. The sheet S is supported and transported on the sheet transport surface 2100P of the rotating print belt 2201 so that the gap (print gap) between the sheet S and the recording unit 2300 (specifically, the tip of the ink ejection nozzle of the recording head) is a predetermined interval for each thickness of the sheet S. To achieve this, the print belt 2201 is formed with a large number of fine holes that allow air to pass through all around, and a suction unit 2260 is disposed vertically below the print belt 2201. The suction unit 2260 sucks air downward to adsorb the sheet S to the sheet transport surface 2100P of the print belt 2201. In this way, a clearance is ensured between the sheet S and the recording head.

[0028] As a means for adjusting the gap between the tip of the ink ejection nozzle of the recording head and the sheet S, a means for moving the recording unit 2300 or a means for moving the print belt unit 2200 can be mentioned. In this embodiment, the print belt unit 2200 is moved from the viewpoint of suppressing color misregistration and suppressing an increase in the size of the device. Also, the thickness of the sheet S may be determined from information about the sheet S input by an operator from an operation panel (not shown) or the like, or may be determined from a detection signal of a thickness detection sensor (not shown) arranged upstream of the recording unit 2300.

[0029] The number of ink colors and recording heads in the print module 2000 are not limited to five. The inkjet method may be a method using a heating element, a method using a piezoelectric element, a method using an electrostatic element, a method using a MEMS (Micro Electro Mechanical Systems) element, or the like. Ink of each color is supplied to the recording head from an ink tank (not shown) via an ink tube. The sheet S printed by the recording section 2300 is transported by the print belt unit 2200, and an in-line scanner (not shown) arranged downstream of the recording section in the transport direction can detect the misalignment and color density of the image formed on the sheet S and correct the printed image.

[0030] <Drying module> Next, the drying module 3000 will be described with reference to Fig. 2. As shown in Fig. 2, the drying module 3000 has a cold air blowing unit 3100, a decoupling belt unit 3200, a drying belt unit 3300, and a hot air blowing unit 3400, which are housed in a housing 300 serving as a second housing. An openable and closable front cover 301 is provided on the front of the housing 300, and an operator can perform maintenance or replacement of the cold air blowing unit 3100, the decoupling belt unit 3200, the drying belt unit 3300, and the hot air blowing unit 3400 by opening the front cover 301 as necessary.

[0031] A side cover 302 is provided on the side of the housing 300 facing the print module 2000, and a receiving port 302a is formed in the side cover 302 to receive the sheet S discharged from the print module 2000 into the drying module 3000. Legs 310 functioning as height changers that can change the height of the housing 300 are provided at each of the four corners on the bottom surface of the housing 300. The housing 300 is moved in the vertical direction in response to changing the length of these legs 310. This changes the heights of the cold air blowing unit 3100, the decoupling belt unit 3200, the drying belt unit 3300, the hot air blowing unit 3400, and even the receiving port 302a from the installation surface.

[0032] The sheet S on which an image is formed by the print module 2000 is conveyed by a decoupling belt unit 3200 as a second conveying unit in the drying module 3000. The decoupling belt unit 3200 has an endless decoupling belt 3201 and a plurality of tension rollers 3270a, 3270b, 3270c, and 3270d that rotatably stretch the decoupling belt 3201. At least one of the tension rollers 3270a, 3270b, 3270c, and 3270d is a drive roller that rotates and drives the decoupling belt 3201. The decoupling belt 3201 as a second belt conveys the sheet S by rotating. The decoupling belt 3201 is tensioned by a tension roller 3270b as a first roller on the downstream side in the conveying direction of a sheet conveying surface 3201P that conveys the sheet S, and is tensioned by a tension roller 3270a as a second roller on the upstream side in the conveying direction of the sheet conveying surface 3201P.

[0033] In the decoupling belt unit 3200 of this embodiment, the sheet S is not suction-conveyed. Therefore, the decoupling belt unit 3200 does not have a fan for suction. This is to prevent the decoupling belt unit 3200 from pulling the sheet S on which an image has been formed by the print module 2000.

[0034] One of the tension rollers that tension the decoupling belt 3201 in a portion other than the sheet conveying surface 3201P, such as tension rollers 3270c and 3270d, is subjected to steering control. The steering control swings the roller so as to move the belt in the front-rear direction (see the front-rear arrow in FIG. 3). The steering control prevents the belt from moving in the front-rear direction and coming off the roller.

[0035] In the decoupling belt unit 3200, a frictional force is generated between the sheet S and the decoupling belt 3201 by the wind pressure of the cold air blown from the cold air blowing unit 3100, and the sheet S is carried and transported by the decoupling belt 3201. In this way, the sheet S is transported by the frictional force, so that when the sheet S is transported between the print belt unit 2200 and the decoupling belt unit 3200, it is not transported while being pulled toward the decoupling belt unit 3200.

[0036] The sheet S conveyed by the decoupling belt unit 3200 is delivered to a drying belt unit 3300 as a third conveying unit. The drying belt unit 3300 has an endless drying belt 3301 and a plurality of tension rollers that rotatably stretch the drying belt 3301. At least one of the tension rollers is a drive roller that rotates and drives the drying belt 3301 as a third belt. In the drying belt unit 3300, ink applied to the sheet S is dried by blowing hot air from a hot air blowing unit 3400. By utilizing this, the drying belt 3301 carries and conveys the sheet S on a sheet conveying surface 3301P by the wind pressure of the hot air blown from the hot air blowing unit 3400. Note that the ink drying method may be appropriately combined with, in addition to the method of blowing hot air, an electromagnetic wave method in which electromagnetic waves (such as ultraviolet rays or infrared rays) are irradiated onto the sheet S, or a conductive heat transfer method by contact with a heating element.

[0037] In this embodiment, when the leading edge of the sheet S in the transport direction reaches the decoupling belt 3201, an image is formed on the sheet S by the recording unit 2300 in a state where the trailing edge of the sheet S in the transport direction is on the print belt 2201. At that time, in order to prevent image defects such as color shift from occurring on the sheet S, the sheet transport force of the decoupling belt 3201 is set smaller than the sheet transport force of the print belt 2201.

[0038] As described above, in the print module 2000, the sheet S is suction-conveyed to the print belt 2201. In order to transport the sheet S with a transport force smaller than that of the print belt 2201, in the drying module 3000, as described above, the sheet S is transported by the frictional force generated by blowing cold air from the cold air blowing unit 3100. Also, the decoupling belt 3201 is rotated at a speed faster than the print belt 2201. For example, the decoupling belt 3201 is rotated at a speed "about 3%" faster than the print belt 2201. In this way, while the rear end of the sheet S is on the print belt 2201, the sheet S is transported while sliding on the decoupling belt 3201, and therefore the sheet S is not transported while being pulled toward the decoupling belt unit 3200.

[0039] However, when the conveying force of the decoupling belt 3201 is smaller than that of the print belt 2201, if a step occurs between the downstream end of the sheet conveying surface 2201P of the print belt 2201 and the upstream end of the sheet conveying surface 3201P of the decoupling belt 3201, there is a risk of poor conveyance of the sheet S. When the print belt 2201 and the decoupling belt 3201 are provided in separate housings 200 and 300, as already described, even if the heights of the housings 200 and 300 are adjusted, the heights of the downstream end of the sheet conveying surface 2201P and the upstream side of the sheet conveying surface 3201P may not match due to component tolerances, etc., and there is a risk of a step occurring.

[0040] <Adjustment mechanism> Therefore, in this embodiment, in order to match the height of the downstream end of the sheet transport surface 2201P with the height of the upstream side of the sheet transport surface 3201P, the height of the decoupling belt 3201 on the upstream side of the sheet transport surface 3201P is made adjustable. To achieve this, a first adjustment mechanism 3A as an adjustment unit (first adjustment unit) is provided in the drying module 3000. Hereinafter, the first adjustment mechanism 3A will be described with reference to FIGS. 2 and 3.

[0041] 2, the first adjustment mechanism 3A is disposed below the decoupling belt unit 3200 in the drying module 3000. In this embodiment, the first adjustment mechanism 3A abuts against the decoupling belt unit 3200 from below, and rotates the decoupling belt unit 3200 around a rotation shaft, thereby changing the height of the upstream side of the sheet conveying surface 3201P.

[0042] 3, the decoupling belt unit 3200 is rotatably supported by a support portion 380 fixed to the housing 300. A rotation shaft 312 is provided at a downstream end portion of the support portion 380 in the conveying direction of the sheet S. More specifically, the rotation shaft 312 is disposed downstream of the center of the sheet conveying surface 3201P in the conveying direction and along the rotation axis direction of the tension roller 3270b.

[0043] The decoupling belt unit 3200 has a front plate 3203 on the front side, and a rear plate 3204 on the rear side sandwiching the decoupling belt 3201. The front plate 3203 and the rear plate 3204 rotatably support tension rollers 3270a, 3270b, 3270c, and 3270d that tension the decoupling belt 3201. The front plate 3203 and the rear plate 3204 are formed with a hook portion 3210 that rotatably engages with the rotating shaft 312. The decoupling belt unit 3200 is supported on the downstream side by the rotating shaft 312 via the hook portion 3210 as an engaging portion.

[0044] The decoupling belt unit 3200 is supported by the rotating shaft 312 via the hook portion 3210, so that the height of the downstream side of the sheet conveying surface 3201P is approximately equal to the height of the upstream side of the sheet conveying surface 3301P of the drying belt 3301. The hook portion 3210 may be provided on the support portion 380, and the rotating shaft 312 may be provided on the decoupling belt unit 3200, so that the decoupling belt unit 3200 is rotatably supported by the support portion 380.

[0045] The decoupling belt unit 3200 has a guard plate 3205 on the upstream side for protecting the decoupling belt 3201. The guard plate 3205 is disposed between the front plate 3203 and the rear plate 3204 so as to cover a part of the decoupling belt 3201 stretched between the tension roller 3270a and the tension roller 3270d. A first adjustment mechanism 3A is provided on the support portion 380 so as to come into contact with the guard plate 3205. The first adjustment mechanism 3A is fixed to the support portion 380 by a fixing portion 315.

[0046] The first adjustment mechanism 3A has an upstream adjustment cam 311, an adjustment dial 314, and a rod-shaped member 313 that connects the upstream adjustment cam 311 and the adjustment dial 314. The rod-shaped member 313 is rotatably supported by a fixed portion 315, and the adjustment dial 314 is attached to one end on the front side of the rod-shaped member 313, and the upstream adjustment cam 311 is attached to the other end of the rod-shaped member 313. In other words, when the adjustment dial 314 is rotated by an external force, the rod-shaped member 313 rotates, causing the upstream adjustment cam 311 to rotate.

[0047] The upstream-side adjustment cam 311 is an eccentric cam, and abuts against a guard plate 3205 of the decoupling belt unit 3200. Therefore, when the upstream-side adjustment cam 311 rotates, the decoupling belt unit 3200 rotates about the rotation shaft 312, so that the upstream side of the decoupling belt unit 3200 is lifted up from the support portion 380. Thus, the height of the upstream side of the sheet conveying surface 3201P in the drying module 3000 changes.

[0048] The adjustment dial 314 as an operation unit has a dial that can be rotated stepwise by a predetermined angle by the user, and the upstream adjustment cam 311 rotates, for example, by "12°" by turning the dial one step. The cam radius of the upstream adjustment cam 311 at the point where it abuts against the guard plate 3205 varies in units of "approximately 0.066 mm" every time the upstream adjustment cam 311 rotates "12°". In this embodiment, the adjustment dial 314 is displayed with a scale in units of "0.5 mm" indicating the amount of variation in the upstream height of the sheet transport surface 3201P so that the operator can manually adjust the upstream height of the sheet transport surface 3201P. This allows the operator to finely adjust the upstream height of the sheet transport surface 3201P by operating the adjustment dial 314 step by step while watching the scale.

[0049] As described above, in this embodiment, the drying module 3000 connected downstream of the print module 2000 is provided with the first adjustment mechanism 3A for stepwise rotating the decoupling belt unit 3200. The first adjustment mechanism 3A rotates the decoupling belt unit 3200, so that the height of the upstream side of the sheet transport surface 3201P of the decoupling belt 3201 is adjusted to the height of the downstream side of the sheet transport surface 2201P of the print belt 2201. With this, even if the heights of the downstream end of the sheet transport surface 2201P and the upstream side of the sheet transport surface 3201P do not match due to component tolerances or the like despite the adjustment of the heights of the housing 200 of the print module 2000 and the housing 300 of the drying module 3000, the operator can easily adjust the height by opening the front cover 301 and operating the first adjustment mechanism 3A. Therefore, no step occurs between the downstream end of the sheet transport surface 2201P and the upstream end of the sheet transport surface 3201P, and transport defects in the sheet S transported between the housings can be suppressed.

[0050] <Other embodiments> In the above embodiment, the upstream adjustment cam 311 is brought into contact with the guard plate 3205 of the decoupling belt unit 3200 to adjust the height, but the present invention is not limited to this. For example, the upstream adjustment cam 311 may be brought into contact with bearings (not shown) that support the tension roller 3270a in the front plate 3203 and the rear plate 3204 to adjust the height, or the upstream adjustment cam 311 may be brought into contact with edges of the front plate 3203 and the rear plate 3204 to adjust the height. Alternatively, the first adjustment mechanism 3A may be provided in the decoupling belt unit 3200, and an abutment portion for abutting the upstream adjustment cam 311 on the support portion 380 may be provided.

[0051] A plurality of upstream adjustment cams 311 having the same shape and phase may be provided on the rod-shaped member 313, or one or a plurality of upstream adjustment cams 311 may be provided on the rod-shaped member 313 arranged at three or more locations in the conveying direction.

[0052] It is also possible to configure the rod-shaped member 313 of the upstream adjustment cam 311 to be rotatable by a motor without providing the adjustment dial 314. In such a case, the motor may be controlled to rotate the upstream adjustment cam 311 via the rod-shaped member 313 in response to the print gap being adjusted by the movement of the print belt unit 2200, so that the height of the upstream side of the sheet transport surface 3201P can be automatically adjusted.

[0053] Incidentally, in the drying module 3000, in order to perform drying according to the characteristics of the sheet S and the image to be printed, it is necessary to form an appropriate gap (drying gap) between the hot air blowing unit 3400 and the sheet S. From the viewpoint of suppressing an increase in the size of the device, in this embodiment, the drying belt unit 3300 is moved up and down so that an appropriate drying gap can be formed. However, when the drying belt unit 3300 is moved, there is a risk that the height of the downstream end of the sheet conveying surface 3201P of the decoupling belt unit 3200 and the upstream side of the sheet conveying surface 3301P of the drying belt unit 3300 do not match.

[0054] Therefore, in order to match the height of the downstream side of the sheet transport surface 3201P with the height of the upstream side of the sheet transport surface 3301P, it is preferable to make the height of the decoupling belt 3201 on the downstream side of the sheet transport surface 3201P adjustable. To achieve this, a second adjustment mechanism 3C is provided on the downstream side of the decoupling belt unit 3200. Fig. 4 shows a case where the second adjustment mechanism 3C is provided on the downstream side of the decoupling belt unit 3200. Note that, here, the same components as those in the print module 2000 and drying module 3000 shown in Fig. 2 are denoted by the same reference numerals, and descriptions thereof will be simplified or omitted.

[0055] As shown in FIG. 4, the second adjustment mechanism 3C as the second adjustment part moves the downstream side of the decoupling belt unit 3200 upward. The second adjustment mechanism 3C has a downstream side adjustment cam 350, a link member 3206, an adjustment dial 314 and a rod-shaped member 313, which are not shown here. The downstream side adjustment cam 350 is disposed outside the front plate 3203 (see FIG. 3) of the decoupling belt unit 3200. The link member 3206 is rotatably provided outside the front plate 3203 so that one end abuts against the rotating shaft 312 and the other end abuts against the downstream side adjustment cam 350. In this case, the rotating shaft 312 is provided so as to be vertically movable with respect to the front plate 3203.

[0056] When the adjustment dial 314 is rotated by an external force, the rod-shaped member 313 rotates, and the downstream adjustment cam 350 rotates. The downstream adjustment cam 350 is an eccentric cam, and is in contact with the other end of the link member 3206. Therefore, when the downstream adjustment cam 350 rotates, the link member 3206 rotates, and one end of the link member 3206 moves up and down on the rotation shaft 312. As a result, the decoupling belt unit 3200 rotates around the upstream adjustment cam 311 while in contact with the upstream adjustment cam 311, and the downstream side of the decoupling belt unit 3200 is lifted up. In this way, the height of the downstream side of the sheet conveying surface 3201P in the drying module 3000 changes. In this way, even if the drying belt unit 3300 is moved, no step is created between the downstream end of the sheet conveying surface 3201P and the upstream end of the sheet conveying surface 3301P, and conveying problems in the sheet S conveyed from the decoupling belt 3201 to the drying belt 3301 can be suppressed.

[0057] 4, a first transport guide 2910 for guiding the sheet S may be provided between the sheet transport surface 2201P of the print belt 2201 and the sheet transport surface 3201P of the decoupling belt 3201. In this embodiment, the first transport guide 2910 is fixed to the front plate 3203 and the rear plate 3204 (see FIG. 3) of the decoupling belt unit 3200. Therefore, when the decoupling belt unit 3200 is rotated by the first adjustment mechanism 3A, the first transport guide 2910 moves following the movement of the upstream end of the sheet transport surface 3201P. In this way, the height of the first transport guide 2910 changes according to the height of the upstream side of the sheet transport surface 3201P, so that the sheet S can be stably transported between the housings 200 and 300 by the first transport guide 2910, and transport defects in the sheet S transported between the housings can be further suppressed.

[0058] Furthermore, a second conveying guide 3240 for guiding the sheet S may be provided between the sheet conveying surface 3201P of the decoupling belt 3201 and the sheet conveying surface 3301P of the drying belt 3301. In this embodiment, the second conveying guide 3240 is fixed to the front plate 3203 and the rear plate 3204 (see FIG. 3) of the decoupling belt unit 3200. Therefore, when the decoupling belt unit 3200 is moved by the second adjustment mechanism 3C, the second conveying guide 3240 moves following the movement of the downstream end of the sheet conveying surface 3201P. In this way, the height of the second conveying guide 3240 changes according to the height of the downstream side of the sheet conveying surface 3201P, so that the sheet S can be stably conveyed between the decoupling belt 3201 and the drying belt 3301 by the second conveying guide 3240 even if the height of the downstream side of the sheet conveying surface 3201P changes. [Explanation of symbols]

[0059] 3A...adjustment section (first adjustment section, first adjustment mechanism), 3C...second adjustment section (second adjustment mechanism), 100...inkjet recording apparatus, 200...first housing (housing), 300...second housing (housing), 310...height change section (leg), 311...eccentric cam (upstream side adjustment cam), 312...rotating shaft, 313...rod-shaped member, 314...operation section (adjustment dial), 380...support section, 2200...first conveying unit (print belt unit), 2201...first belt ( print belt), 2300... recording section, 2910... transport guide, 3200... second transport unit (decoupling belt unit), 3201... second belt (decoupling belt), 3201P... sheet transport surface, 3210... engagement section (hook section), 3270a... second roller (tension roller), 3270b... first roller (tension roller), 3300... third transport unit (drying belt unit), 3301... third belt (drying belt), S... sheet

Claims

1. An inkjet recording apparatus for forming an image on a sheet with ink, a first conveying unit having an endless first belt for conveying a sheet; a recording unit that ejects ink onto a sheet transported by the first belt to form an image; a first housing that houses the first transport unit and the recording unit; a second housing disposed downstream of the first housing in a sheet conveying direction and connected to the first housing; a second conveying unit including: an endless second belt that is housed in the second housing and conveys a sheet delivered by the first belt; a first roller that stretches the second belt; and a second roller that is disposed upstream of the first roller in the conveying direction and stretches the second belt; a third conveying unit disposed downstream of the second conveying unit in the second housing in the conveying direction and having an endless third belt that conveys a sheet delivered by the second belt; In the second belt, a space between the first roller and the second roller serves as a sheet transport surface, and the sheet is transported on the sheet transport surface, an adjustment unit provided in the second housing and capable of adjusting a height of the upstream side of the sheet conveying surface stretched over the second roller in the conveying direction by rotating the second conveying unit with respect to the second housing about a rotation axis disposed downstream of a center of the sheet conveying surface in the conveying direction and along a rotation axis direction of the first roller; 1. An ink jet recording apparatus comprising:

2. The rotation shaft is disposed downstream of the first roller in the conveying direction.

2. The inkjet recording apparatus according to claim 1,

3. a support portion for supporting the second conveying unit, the rotation shaft is provided at a downstream end of the support portion in the conveying direction, the second conveying unit has an engagement portion that rotatably engages with the rotation shaft; 3. The inkjet recording apparatus according to claim 2,

4. the adjustment unit has a rod-shaped member rotatably disposed on the support unit along the rotation axis direction, and an eccentric cam fixed to the rod-shaped member and in contact with the second conveying unit, and the second conveying unit is rotated by the eccentric cam rotating together with the rod-shaped member.

4. The inkjet recording apparatus according to claim 3,

5. An operation unit that allows a user to manually rotate the rod-shaped member is provided.

5. The inkjet recording apparatus according to claim 4,

6. the adjustment unit is a first adjustment unit, a second adjustment unit that is capable of adjusting a height of a downstream side of the sheet conveying surface stretched over the first roller in the conveying direction by rotating the second conveying unit about the rod-shaped member in a state in which the eccentric cam is in contact with the second housing, 5. The inkjet recording apparatus according to claim 4,

7. a conveying guide provided in the second conveying unit to guide the sheet conveyed by the first belt to the second belt; the conveying guide moves together with the rotation of the second conveying unit by the adjustment unit.

2. The inkjet recording apparatus according to claim 1,

8. a height changing unit capable of changing the height of the second housing relative to the first housing; 2. The inkjet recording apparatus according to claim 1,

Images