This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2021-180107 filed on Nov. 4, 2021, the entire contents of which are hereby incorporated by reference.
The present disclosure relates to an inkjet recording device that ejects ink through ink ejection nozzles of a recording head so as to perform recording.
As a recording device such as a facsimile machine, a copier, or a printer, an inkjet recording device is widely used, which ejects ink through the nozzles of the recording head to form an image, so that a high definition image can be formed.
Such an inkjet recording device has a problem that paper dust generated from a paper sheet as a recording medium might clog the nozzle and cause a nozzle ejection failure (missing dot), resulting in lowering of image quality.
An inkjet recording device according to an aspect of the present disclosure includes a conveying unit, a recording unit, a sucking roller, and a sucking device. The conveying unit conveys a paper sheet by use of an endless conveyor belt. The recording unit includes a recording head disposed to face a carrying surface of the conveyor belt so as to eject ink through ink ejection nozzles of the recording head to the paper sheet being conveyed by the conveyor belt. On an upstream side of the recording unit in a sheet conveying direction, the sucking roller makes contact with the paper sheet being conveyed and rotates in that state. The sucking device is joined to the sucking roller. The sucking roller is columnar in outer shape and has many air sucking holes formed in a side surface thereof so that air in a vicinity of the sucking roller is sucked through the air sucking holes by the sucking device.
Hereinafter, an embodiment of the present disclosure is described with reference to the drawings.
As illustrated in
In addition, a first sheet conveying path 4a is provided inside the printer 100. The first sheet conveying path 4a is positioned on the upper right side of the sheet feed cassette 2a, i.e. on the left side of the manual sheet feeding tray 2b. The paper sheet P sent out from the sheet feed cassette 2a passes through the first sheet conveying path 4a and is conveyed vertically upward along the side surface of the printer main body 1. The paper sheet sent out from the manual sheet feeding tray 2b passes through the first sheet conveying path 4a and is conveyed substantially horizontally to the left.
A registration roller pair 13 is provided at a downstream end of the first sheet conveying path 4a in the sheet conveying direction. Further, the first belt conveying unit (conveying unit) 5 and the recording unit 9 are disposed near the registration roller pair 13 on the downstream side. The registration roller pair 13 corrects a skew of the paper sheet P, and sends out the paper sheet P to the first belt conveying unit 5 in synchronization with an ink ejection operation by the recording unit 9.
In addition, between the registration roller pair 13 and the first belt conveying unit 5, there is disposed a contact image sensor (CIS) 20 as a sheet detection sensor for detecting an end position of the paper sheet P in its width direction (in a direction perpendicular to the sheet conveying direction).
The first belt conveying unit 5 includes an endless first conveyor belt 8 (see
A sucking roller 60 is disposed upstream of the recording unit 9 in the sheet conveying direction and at a position facing an upstream end of the first conveyor belt 8. The sucking roller 60 makes contact with the carrying surface 8a of the first conveyor belt 8 or the paper sheet P placed on the carrying surface 8a so as to be conveyed, and rotates in that state following rotation of the first conveyor belt 8. A detailed configuration of the sucking roller 60 will be described later.
A plate-shaped member 25 is disposed between the recording unit 9 and the sucking roller 60. The plate-shaped member 25 is secured to a head housing 10 holding line heads 11C, 11M, 11Y, and 11K and is disposed substantially parallel to the carrying surface 8a of the first conveyor belt 8 at a predetermined gap therefrom. The plate-shaped member 25 faces the first conveyor belt 8 over an entire area in a width direction thereof (a direction perpendicular to a plane on which
A first sheet sucking unit 30 is provided at a location facing a backside of the carrying surface 8a of the first conveyor belt 8, inside the loop of the first conveyor belt 8. The first sheet sucking unit 30 has many holes 30a formed in an upper surface thereof for sucking air, and inside the first sheet sucking unit 30, there is provided a first fan 30b that can suck air downward through the upper surface. In addition, the first conveyor belt 8 also has many air holes 8b for sucking air (see
The recording unit 9 includes the line heads 11C, 11M, 11Y, and 11K that perform recording of an image on the paper sheet P being conveyed while sucked and held on the carrying surface 8a of the first conveyor belt 8. Inks in the line heads 11C to 11K are sequentially ejected therefrom to the paper sheet P sucked on the first conveyor belt 8 so as to correspond to information of image data received from an external computer or the like. With this configuration, four color inks of cyan, magenta, yellow, and black are superimposed so that a full-color image is recorded on the paper sheet P. The printer 100 can also record a monochrome image.
As illustrated in
The recording heads 17a to 17c constituting each of the line heads 11C to 11K are supplied with ink of the corresponding color among the four color inks (cyan, magenta, yellow, and black color inks), which are respectively stored in ink tanks (not shown).
Each of the recording heads 17a to 17c can eject ink through the ink ejection nozzles 18 corresponding to print positions in accordance with image data received from an external computer or the like, to the paper sheet P being conveyed while sucked and held on the carrying surface 8a of the first conveyor belt 8. With this configuration, the cyan, magenta, yellow, and black color inks are superimposed so that a color image is formed on the paper sheet P on the first conveyor belt 8.
On the downstream side (the left side in
The second belt conveying unit 12 includes an endless second conveyor belt 40 stretched around a second drive roller 41 and a second driven roller 42. The second conveyor belt 40 is driven by the second drive roller 41 to turn in a counterclockwise direction in
A second sheet sucking unit 43 is provided at a location facing a backside of a carrying surface 40a of the second conveyor belt 40, inside the loop of the second conveyor belt 40. The second sheet sucking unit 43 has many holes 43a formed in an upper surface thereof for sucking air, and inside the second sheet sucking unit 43, there is provided a second fan 43b that can suck air downward through the upper surface. In addition, the second conveyor belt 40 also has many air holes for sucking air (not shown). With the configuration described above, the second belt conveying unit 12 conveys the paper sheet P while sucking and holding the same on the carrying surface 40a of the second conveyor belt 40.
In addition, a conveyance guide part 50 is provided at a position facing the carrying surface 40a of the second conveyor belt 40. The conveyance guide part 50 constitutes a sheet conveyance path together with the carrying surface 40a of the second conveyor belt 40 and suppresses warping or fluttering of the paper sheet P sucked and held on the carrying surface 40a by the second sheet sucking unit 43.
A decurler unit 14 is provided downstream of the second belt conveying unit 12 in the sheet conveying direction and in a vicinity of a left side surface of the printer main body 1. The paper sheet P after the inks are dried in the second belt conveying unit 12 is conveyed to the decurler unit 14, which corrects a curl of the paper sheet P.
On the downstream side (the upper side in
In addition, a maintenance unit 19 is disposed below the second belt conveying unit 12. When performing maintenance of the recording heads 17, the maintenance unit 19 moves to below the recording unit 9, wipes ink pushed out (purged) from the ink ejection nozzles 18 (see
The belt drive motors 21 and 22 respectively drive the first drive roller 6 and the second drive roller 41 to rotate, so that the first conveyor belt 8 and the second conveyor belt 40 can turn. The fan drive motors 23 and 24 respectively drive the first fan 30b of the first sheet sucking unit 30 and the second fan 43b of the second sheet sucking unit 43 to rotate.
The operation panel 27 is an operation unit for receiving various setting inputs. For instance, by operating the operation panel 27, a user can input a size of the paper sheets P set in the sheet feed cassette 2a or on the manual sheet feeding tray 2b, i.e. information of a size of the paper sheet P that is conveyed by the first conveyor belt 8. In addition, by operating the operation panel 27, the user can also input the number of the paper sheets P to be printed or instruct a start of a print job. In addition, the operation panel 27 also has a function as a notification device for notifying about an operating state of the printer 100.
The storage unit 28 is a memory for storing an operation program of a control unit 110 and various sets of information, and it includes a read only memory (ROM), a random access memory (RAM), a nonvolatile memory, and the like. The information set by the operation panel 27 is stored in the storage unit 28.
The communication unit 29 is a communication interface for communicating information with an external device (such as a personal computer (PC)). For instance, when the user operates the PC and sends a print command with image data to the printer 100, the image data and the print command are input to the printer 100 via the communication unit 29. In the printer 100, a main control portion 110a controls the recording heads 17a to 17c to eject ink on the basis of the image data, so that an image can be recorded on the paper sheet P.
The sucking device 70 is joined to the sucking roller 60 and sucks paper dust of the paper sheet P to be conveyed to the recording unit 9 via the sucking roller 60.
In addition, the printer 100 according to this embodiment includes the control unit 110. The control unit 110 is constituted of a central processing unit (CPU) and a memory, for example. Specifically, the control unit 110 includes the main control portion 110a, a sheet suction control portion 110b, a sheet supply control portion 110c, and a maintenance control portion 110d.
The main control portion 110a controls operations of individual units in the printer 100. For instance, drive of each roller in the printer 100, ink ejection from the recording heads 17a to 17c when recording an image, and the like are controlled by the main control portion 110a. The main control portion 110a also drives the sucking device 70 to remove paper dust of the paper sheet P to be conveyed to the recording unit 9.
The sheet suction control portion 110b sends a control signal to the fan drive motors 23 and 24 so as to control rotations of the first fan 30b and the second fan 43b, and thus a state of the paper sheet P sucked and held on the first conveyor belt 8 or the second conveyor belt 40 can be controlled.
The sheet supply control portion 110c is a recording medium supply control portion that controls the registration roller pair 13 as a recording medium supply unit. For instance, the sheet supply control portion 110c controls the registration roller pair 13 based on a detection timing of a rear end of the paper sheet P by the CIS 20, and thus controls a conveyance timing of the following paper sheet P.
The maintenance control portion 110d controls the recording heads 17a to 17c to perform the purge operation described above in which the ink ejection nozzles 18 push out ink in a forced manner. When the maintenance control portion 110d controls the recording heads 17a to 17c to perform the purge operation, it also controls drive of the maintenance unit 19 described above (e.g. movement to below the recording unit 9 and retraction).
Note that the control unit 110 may further include a calculation portion that performs necessary calculation and a time measuring portion that measures time. In addition, the main control portion 110a may also works as the calculation portion or the time measuring portion described above.
As described above, there is the problem that paper dust generated from the paper sheet P might clog the ink ejection nozzles 18 of the recording heads 17 and cause an ink ejection failure (missing dot) of the ink ejection nozzles 18, resulting in lowering of image quality. Therefore, the printer 100 according to this embodiment uses the sucking roller 60 and the sucking device 70 to suck paper dust of the paper sheet P to be conveyed to the recording unit 9.
The sucking roller 60 has a columnar shape and includes the roller main body 61 of a cylindrical shape and a first rotary shaft 62a and a second rotary shaft 62b that are provided respectively at both ends of the roller main body 61 in the axial direction. The roller main body 61 is hollow and has many air sucking holes 63 formed in an outer circumferential surface (a columnar side surface) thereof. The air sucking holes 63 have a diameter of approximately 1 to 2 mm.
The first rotary shaft 62a has a hollow cylindrical shape with both ends thereof open and is secured on the rear side in the printer 100. That is, the first rotary shaft 62a is provided at one end of the roller main body 61 in the axial direction. One end of the first rotary shaft 62a is inserted into the one end of the roller main body 61 in the axial direction. A first bearing 65a is secured to the one end of the roller main body 61 in the axial direction so that the one end of the roller main body 61 in the axial direction is supported so as to be rotatable about the first rotary shaft 62a as a support axis. That is, one end of the sucking roller 60 (on the rear side) is supported so as to be rotatable by frictional motion between the first rotary shaft 62a and the first bearing 65a. The sucking device 70 is joined to the roller main body 61 via the first rotary shaft 62a. Specifically, the other end of the first rotary shaft 62a is connected to the sucking device 70.
The second rotary shaft 62b is secured to an end (the other end) of the roller main body 61 in the axial direction on the opposite side to the first rotary shaft 62a and is rotatably supported by a second bearing 65b that is secured on the front side in the printer 100. That is, the other end of the sucking roller 60 (on the front side) is supported so as to be rotatable by frictional motion between the second rotary shaft 62b and the second bearing 65b.
The sucking device 70 includes a sucking fan 71 and a filter 73. As shown by arrows in
At a time of image recording on the paper sheet P, the main control portion 110a transmits a control signal to the sucking device 70 so as to drive the sucking fan 71 to rotate. With this configuration, before the paper sheet P fed from the sheet feed cassette 2a or the manual sheet feeding tray 2b is conveyed to the recording unit 9, paper dust adhering to the paper sheet P is sucked together with air through the air sucking holes 63 into the sucking roller 60 rotating in contact with the paper sheet P. The paper dust sucked into the sucking roller 60 passes through the first rotary shaft 62a and then is collected by the sucking filter 73 in the sucking device 70. Accordingly, it is possible to reduce paper dust adhering to the paper sheet P to be conveyed to the recording unit 9 and thus to suppress clogging of the ink ejection nozzles 18 caused by paper dust.
In addition, between the sucking roller 60 and the recording unit 9, the plate-shaped member 25 (see
When air is sucked through the air sucking holes 63 into the sucking roller 60 at a time of image recording on the paper sheet P, the paper sheet P passing through the sucking roller 60 might be wrapped around the sucking roller 60 under a negative pressure, causing a paper jam.
To avoid the above situation, as shown in
According to a configuration shown in
According to a configuration shown in
In a case where the sucking roller 60 shown in
Other than the above, without being limited to the embodiment described above, the present disclosure can be variously modified within a scope not departing from the spirit thereof. For example, while the above embodiment describes a case where the paper sheet P is conveyed in a state of being sucked by negative-pressure suction on the first conveyor belt 8 and the second conveyor belt 40, the first conveyor belt 8 and the second conveyor belt 40 may be charged so that the paper sheet P is conveyed in a state of being sucked by electrostatic suction on the first conveyor belt 8 and the second conveyor belt 40 (an electrostatic suction method).
In addition, the above embodiment describes the line head type printer 100 as the inkjet recording device, which performs recording with the line heads 11C to 11K, each of which includes the recording heads 17a to 17e having the many ink ejection nozzles 18 arranged in the sheet width direction, but the present disclosure can be similarly applied to a serial type inkjet recording device that performs recording with a recording head 17 that moves over a sheet.
The present disclosure can be used for inkjet recording devices that perform recording by ejecting ink through the ink ejection nozzles of the recording head. Using the present disclosure, it is possible to provide the inkjet recording device that can effectively remove paper dust generated from a paper sheet, with a simple configuration.
Number | Date | Country | Kind |
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2021-180107 | Nov 2021 | JP | national |