Image forming device

Abstract

To provide an image forming device capable of achieving miniaturization and suppressing contamination in the device.SOLUTION: This image forming device comprises: a recording head 14 that discharges an ink; a conveyor belt 15 on which a sheet M is conveyed vertically upward; a conveying moving unit 17 that rotates the conveyor belt; a charging roller 21 that charges the conveyor belt; a charging moving unit 22 that moves the charging roller between a charging contact position in contact with the conveyor belt and a charging separation position P2 separated from the conveyor belt; a cleaning member 23 that cleans the conveyor belt; a cleaning moving unit 24 that moves the cleaning member between a cleaning contact position P3 in contact with the conveyor belt and a cleaning separation position separated from the conveyor belt; and a control unit 20 (estimation unit) that estimates staining of the conveyor belt. When the conveyor belt is stained, the charging moving unit moves the charging roller to the charging separation position P2, the cleaning moving unit moves the cleaning member to the cleaning contact position P3, and the conveying moving unit moves the staining present on a conveying region side A1 of the conveyor belt to a cleaning region side A2.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an inkjet image forming apparatus. [Background technology]

[0002] A known recording device includes a recording unit that ejects ink onto paper, a conveyor belt that conveys the paper, and a charging roller that charges the conveyor belt (see Patent Document 1). This recording device also includes a cleaning unit that moves the charging roller in and out of contact with the conveyor belt, a contamination estimation unit that estimates contamination on the conveyor belt, and a belt movement unit that swings the conveyor belt around its axis. When the conveyor belt becomes stained with ink due to a paper jam, the cleaning unit separates the charging roller from the conveyor belt, and the belt movement unit rotates the conveyor belt downward away from the recording unit. This allows for the removal of jammed paper (jam clearance) and also reduces the contamination of the charging roller that accompanies jam clearance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-185679 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above technology, the conveyor belt is rotated downward by the belt moving unit, so that ink or other contaminants adhering to the conveyor belt fall off the conveyor belt and contaminate the inside of the recording device (image forming device).In addition, a large-scale mechanism (belt moving unit) for swinging the conveyor belt must be incorporated into the recording device, and space for swinging the conveyor belt must be secured within the recording device, which causes the recording device to become larger.

[0005] SUMMARY OF THE INVENTION In consideration of the above circumstances, the present invention provides an image forming apparatus that can be made compact and can suppress contamination inside the apparatus that accompanies jam clearance. [Means for solving the problem]

[0006] The image forming apparatus of the present invention includes a recording unit that ejects a liquid toward a medium, a conveyor belt that faces the recording unit and conveys the medium vertically upward or obliquely upward, a conveyance moving unit that rotates the conveyor belt, a charging roller that contacts the rotating conveyor belt to charge the conveyor belt, a charging moving unit that moves the charging roller between a charging contact position where the charging roller contacts the conveyor belt and a charging separation position where the charging roller is separated from the conveyor belt, a cleaning member that contacts a cleaning area side of the rotating conveyor belt that is opposite to the conveying area side that faces the recording unit and cleans the conveyor belt, and the cleaning unit The cleaning device includes a cleaning movement unit that moves a cleaning material between a cleaning contact position where the cleaning material is in contact with the conveying belt and a cleaning separation position where the cleaning material is separated from the conveying belt, and an estimation unit that estimates the dirt on the conveying belt.When the estimation unit estimates that the conveying belt is dirty, the charging movement unit moves the charging roller arranged at the charging contact position to the charging separation position, the cleaning movement unit moves the cleaning member arranged at the cleaning separation position to the cleaning contact position, and the conveying movement unit rotates the conveying belt to move the dirt located on the conveying area side of the conveying belt to the cleaning area side.

[0007] In this case, if the estimation unit estimates that the conveying belt is dirty, the conveying movement unit rotates the conveying belt and positions the dirt located on the conveying area side of the conveying belt upstream of the cleaning member in the rotation direction on the cleaning area side.

[0008] In this case, the estimation unit estimates that the detection of poor transport of the medium on the conveying belt indicates the occurrence of dirt on the conveying belt, and if the estimation unit estimates that the conveying belt is dirty, the charging roller is placed at the charging separation position, the cleaning member is placed at the cleaning contact position, and the dirt on the conveying belt is positioned upstream of the cleaning member in the rotation direction, and the medium that has become poorly transported is removed, and then the conveying movement unit further rotates the conveying belt, causing the cleaning member to remove the dirt from the conveying belt.

[0009] In this case, the cleaning member may be capable of contacting an upper portion of the conveyor belt on the cleaning area side.

[0010] In this case, the device may further include a detection unit that is provided upstream of the recording unit in the transport direction of the medium and detects poor transport of the medium on the transport belt, and the estimation unit may estimate that the transport belt is dirty when the detection unit detects poor transport of the medium. [Effects of the Invention]

[0011] According to the present invention, it is possible to reduce the size of the device and to suppress contamination inside the device that occurs during jam clearance. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram (front view) showing the internal structure of an image forming apparatus according to one embodiment of the present invention. [Figure 2] 2 is a block diagram showing a control unit and the like of the image forming apparatus according to the embodiment of the present invention. FIG. [Figure 3] 5 is a flowchart showing an operation procedure (a method for cleaning a conveyor belt) of a belt cleaning structure of an image forming apparatus according to one embodiment of the present invention. [Figure 4] 1 is a front view illustrating a state in which a jam occurs in an image forming apparatus according to an embodiment of the present invention. [Figure 5]1 is a front view illustrating a belt cleaning structure for an image forming apparatus according to an embodiment of the present invention, illustrating cleaning preparation control. [Figure 6] 1 is a front view illustrating a belt cleaning structure of an image forming apparatus according to an embodiment of the present invention, illustrating jam processing preparation control. [Figure 7] 1 is a front view illustrating a belt cleaning structure for an image forming apparatus according to an embodiment of the present invention, illustrating cleaning control. [Figure 8] FIG. 10 is a schematic diagram (front view) showing the internal structure of an image forming apparatus according to a first modified example of one embodiment of the present invention. [Figure 9] FIG. 10 is a schematic view (front view) showing the internal structure of an image forming apparatus according to a second modified example of one embodiment of the present invention. [Figure 10] 10 is a flowchart showing an operation procedure (a method for cleaning a conveyor belt) of a belt cleaning structure of an image forming apparatus according to a third modified example of one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that Fr, Rr, L, R, U, and D in the drawings represent front, rear, left, right, top, and bottom. Terms indicating directions and positions are used in this specification, but these terms are used for convenience of explanation and do not limit the technical scope of the present invention. Furthermore, terms such as "upstream" and "downstream" refer to "upstream" and "downstream" in the conveyance direction of paper M (medium) and similar concepts. Note that the dimensions and angles of components in each drawing are not accurate and are shown schematically for the purpose of explanation.

[0014] [Image forming equipment] An image forming apparatus 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram (front view) showing the internal structure of the image forming apparatus 1.

[0015] The image forming apparatus 1 is an inkjet printer that ejects ink droplets to form an image on paper M (medium). The image forming apparatus 1 has a box-shaped housing 2 that houses various devices. A paper feed cassette 3 in which paper M is set is housed in the lower part of the housing 2, and a paper output tray 4 on which printed paper M is stacked is provided on the upper surface of the housing 2. A first transport path 5 is formed on the lower left side of the housing 2 for transporting paper M from the paper feed cassette 3 toward the head unit 12. A paper feed unit 10 is provided upstream of the first transport path 5, and a registration roller 11 is provided downstream of the first transport path 5.

[0016] The head unit 12 has four line heads 13 corresponding to four colors of ink: black, cyan, magenta, and yellow. Although not clearly shown in FIG. 1, each line head 13 is equipped with multiple (e.g., three) recording heads 14. The three recording heads 14 are arranged to cover the front-to-rear width of the paper M (the horizontal width perpendicular to the transport direction). Note that each of the multiple recording heads 14 has the same structure, so the following description will mainly focus on one recording head 14.

[0017] <Recording head> The recording head 14, an example of a recording unit, is supported on a head base (not shown) with multiple nozzles (not shown) facing rightward (toward a conveyor belt 15, described later). The recording head 14 has multiple ink chambers corresponding to the multiple nozzles and multiple piezoelectric elements (neither of which is shown) corresponding to the multiple ink chambers. Each piezoelectric element is electrically connected to a high-voltage power supply (not shown), which applies a drive signal (high voltage) to each piezoelectric element under the control of a control unit 20. The recording head 14 is connected to ink packs (not shown) of each color via tubes (not shown) and receives a supply of ink (liquid) from the ink packs. The recording head 14 applies a drive signal to the piezoelectric elements to deform the ink chambers, thereby ejecting ink (liquid) from the nozzles toward the paper M. Although not shown, the image forming apparatus 1 also includes a maintenance unit that prevents and clears clogging of the nozzles of the recording head 14. The maintenance unit includes a cap that seals the nozzle surface of the recording head 14 and a wiper that wipes the nozzle surface.

[0018] <Conveyor belt> A conveyor belt 15 is provided to the right of the head unit 12 so as to face the multiple recording heads 14. The conveyor belt 15 is formed in a ring shape from a flexible material. The conveyor belt 15 is looped around a pair of tension rollers 16A, 16B that are spaced apart in the vertical direction. The conveyor belt 15 has a conveying area side A1 (one surface on the left side) that faces the recording heads 14 and is parallel to the nozzle surfaces of the recording heads 14. As will be described in detail later, the conveyor belt 15 rotates clockwise in FIG. 1 and conveys the paper M vertically upward while electrostatically adsorbing it to the conveying area side A1.

[0019] <Transportation moving section> One (e.g., the upper) tension roller 16A is connected to a transport moving unit 17 via a drive transmission mechanism such as a gear train. The transport moving unit 17 is, for example, an electric motor, and is electrically connected to a power source (not shown) and a control unit 20 (see also FIG. 2, which will be described later). The transport moving unit 17 rotates one tension roller 16A about its axis while being controlled by the control unit 20, thereby causing the conveyor belt 15 to revolve. The other (e.g., the lower) tension roller 16B receives a driving force transmitted via the conveyor belt 15 and rotates about its axis following the movement of one tension roller 16A.

[0020] <Charging roller> A charging roller 21 formed in a substantially cylindrical shape is in contact with the bottom of the conveyor belt 15. The charging roller 21 sandwiches the conveyor belt 15 between itself and the other (for example, lower) tension roller 16B. The charging roller 21 is provided so as to be rotatable about its axis and movable in the vertical direction. The charging roller 21 is electrically connected to a high-voltage power supply (not shown), which applies a high voltage to the charging roller 21 under the control of the control unit 20. The charging roller 21 is provided so as to be rotatable about its axis and contacts the conveyor belt 15 as it rotates, thereby charging the conveyor belt 15.

[0021] A second transport path 6 is formed on the upper left side of the housing 2 to transport the paper M from the head unit 12 toward the paper discharge tray 4. A decurling device 18 is provided upstream of the second transport path 6, and a paper discharge unit 19 is provided downstream of the second transport path 6.

[0022] <Control unit> A control unit 20 is provided inside the housing 2 for appropriately controlling various devices to be controlled. The control unit 20 includes a processor or the like that executes various arithmetic processes in accordance with programs and parameters stored in memory. The processor may be, for example, a CPU (Central Processing Unit). The memory is configured with one or more storage devices such as ROM (Read Only Memory) and RAM (Random Access Memory) depending on the application. Note that the control unit 20 may be realized by a logic circuit (hardware) formed in an integrated circuit or the like, instead of a processor or the like that executes programs or the like.

[0023] An operation panel (touch panel) (not shown) for a user to input operations is provided on the upper front surface of the housing 2. The operation panel is electrically connected to the control unit 20, and the control unit 20 displays various information about the image forming apparatus 1 on the operation panel.

[0024] [Printing Processing] Here, we will explain the printing process (image forming process) by the image forming apparatus 1. The control unit 20 receives a printing instruction (job) from, for example, an external terminal (not shown), and executes the printing process as follows based on the image data input from the external terminal.

[0025] The paper feed unit 10 feeds the paper M taken out of the paper feed cassette 3 to the first transport path 5. The registration rollers 11 temporarily block the paper M to correct skew, and then feed the paper M onto the transport belt 15 in time with the ejection of ink droplets (liquid droplets) from the recording head 14. The transport belt 15 transports the paper M from below to above at a position facing the head unit 12 (recording head 14). The paper M is transported while being electrostatically attracted to the charged transport belt 15, and the head unit 12 (recording head 14) ejects ink (liquid) toward the paper M. As a result, a full-color image is formed (printed) on the paper M. The decurling device 18 straightens out any curl in the paper M fed from the transport belt 15, and the paper ejection unit 19 ejects the paper M transported along the second transport path 6 onto the paper ejection tray 4.

[0026] However, a paper M may fail to be conveyed properly (jam) on the conveyor belt 15. When a jam occurs, the printing process is interrupted. However, ink (liquid) ejected from the recording head 14 may not land (adhere) on the surface of the paper M, but may land (adhere) on the surface of the conveyor belt 15. In other words, when a jam occurs, the conveyor belt 15 may become contaminated with ink (hereinafter, referred to as contaminated ink 99 (see FIG. 4, which will be described later)). Furthermore, when a jam occurs, a user opens a cover (not shown) of the housing 2 and removes the jammed paper M (clears the jam). However, if contaminated ink 99 is attached to the surface of the conveyor belt 15, the user's hands may become contaminated with the contaminated ink 99 while clearing the jam, or the contaminated ink 99 on the conveyor belt 15 may fall and contaminate various devices inside the housing 2. Therefore, the image forming apparatus 1 according to this embodiment is provided with a belt cleaning structure 7 that suppresses contamination inside the apparatus (inside the housing 2) caused by jam clearance.

[0027] <Detection unit> Prior to describing the belt cleaning structure 7, a detection unit 25 that detects a transport failure (jam) of the paper M on the transport belt 15 will be described with reference to Figures 1 and 2. Figure 2 is a block diagram showing the control unit 20 and other components.

[0028] The detection unit 25 is located downstream of the first transport path 5 (upstream of the recording head) (see FIG. 1). The detection unit 25 is, for example, a reflective photoelectric sensor that detects the paper M by irradiating light onto the paper M and receiving the light reflected by the paper M. The detection unit 25 is electrically connected to the control unit 20 and transmits a light reception signal (detection result) to the control unit 20. The control unit 20, for example, compares the elapsed time from when the detection unit 25 detects the paper M until it no longer detects it with a set time stored in memory. The control unit 20 determines that the paper is normal if the elapsed time is within the set time, and determines that a jam has occurred if the elapsed time exceeds the set time. As will be described in detail later, when the control unit 20 detects a paper M transport failure (jam), the control unit 20 assumes that the transport belt 15 is contaminated with contaminated ink 99. Furthermore, when the control unit 20 receives a detection result indicating a jam from the detection unit 25, it stops various devices and interrupts the above-mentioned printing process. The detection unit 25 is not limited to a reflective photoelectric sensor, but may be a transmissive photoelectric sensor, a microswitch, or the like.

[0029] [Belt cleaning structure] 1 and 2, the belt cleaning structure 7 will be described. In addition to the conveyor belt 15, conveyor moving unit 17, control unit 20, and charging roller 21 already described, the belt cleaning structure 7 includes a charging moving unit 22, a cleaning member 23, and a cleaning moving unit 24.

[0030] <Charged transfer section> The charge roller 21 is, for example, an electric motor or the like, and is connected to the charge roller 21 via a drive transmission mechanism such as a gear train. The charge roller 21 is electrically connected to the control unit 20 and moves the charge roller 21 up and down reciprocally under the control of the control unit 20. Specifically, the charge roller 21 moves between a charge contact position P1 where the charge roller 21 is in contact with the conveyor belt 15 and a charge separation position P2 where the charge roller 21 is spaced downward from the conveyor belt 15. The charge roller 21 is controlled by the control unit 20 to position the charge roller 21 at the charge contact position P1 during printing processing and to position the charge roller 21 at the charge separation position P2 when a jam occurs. The charge roller 21 is not limited to an electric motor and may be a solenoid, a cylinder / piston, or the like.

[0031] <Cleaning materials> The cleaning member 23 is formed, for example, in a substantially flat plate shape from an elastically deformable material. The cleaning member 23 is disposed on the opposite side of the conveyor belt 15 from the head unit 12 (recording head 14), i.e., on the right side (cleaning area side A2) of the conveyor belt 15. The cleaning member 23 is tilted upward from the right end to the left end (tip) and is provided so as to be movable in the left-right direction. The tip of the cleaning member 23 contacts the surface of the conveyor belt 15 below the cleaning area side A2 of the conveyor belt 15 (near the other tension roller 16B). As will be described in detail later, contaminated ink 99 adhering to the conveyor belt 15's conveyor area side A1 moves from the conveyor area side A1 to the cleaning area side A2 as the conveyor belt 15 rotates, and is scraped off by the cleaning member 23 in contact with the conveyor belt 15. In other words, the cleaning member 23 cleans the conveyor belt 15 by contacting the cleaning area side A2 of the conveyor belt 15 as it rotates. Although not shown in the figure, the cleaning member 23 is connected to a waste container via a waste tube, and the contaminated ink 99 scraped off the conveyor belt 15 by the cleaning member 23 is collected in the waste container via the waste tube.

[0032] <Cleaning Mobile Unit> The moving cleaning unit 24 is, for example, an electric motor or the like, and is connected to the cleaning member 23 via a drive transmission mechanism such as a gear train. The moving cleaning unit 24 is electrically connected to the control unit 20 and, under the control of the control unit 20, moves the cleaning member 23 back and forth in the left-right direction. Specifically, the moving cleaning unit 24 moves the cleaning member 23 between a cleaning contact position P3 where the cleaning member 23 is in contact with the conveyor belt 15 and a cleaning separation position P4 where the cleaning member 23 is separated from the conveyor belt 15. The moving cleaning unit 24 is controlled by the control unit 20 to position the cleaning member 23 at the cleaning separation position P4 during printing processing and to position the cleaning member 23 at the cleaning contact position P3 when a jam occurs. Note that the moving cleaning unit 24 is not limited to an electric motor and may be a solenoid, a cylinder / piston, or the like.

[0033] [How to clean the conveyor belt] The operation of the belt cleaning structure 7, in other words, the method for cleaning the conveyor belt 15, will be described with reference to Figures 3 to 7. Figure 3 is a flowchart showing the operation procedure of the belt cleaning structure 7 (the method for cleaning the conveyor belt 15). Figure 4 is a front view showing a state in which a jam has occurred in the image forming apparatus 1. Figures 5 to 7 are front views showing the belt cleaning structure 7.

[0034] 3, when the image forming apparatus 1 is powered on or returns from sleep mode to standby mode (step S1), the control unit 20 executes a determination as to whether a print instruction (job) has been received (step S2). Note that in this state, the charging roller 21 is positioned at the charging contact position P1 and is in contact with the conveyor belt 15, and the cleaning member 23 is positioned at the cleaning separation position P4 and is separated from the conveyor belt 15 (see FIG. 1).

[0035] If the control unit 20 determines that "no job has been received" (NO in step S2), it determines whether the elapsed time (T) since power was turned on or since the image forming apparatus 1 returned to standby mode has exceeded the time (sleep transition time Ts) previously stored in memory (step S3). If the elapsed time (T) has not exceeded the sleep transition time (Ts) (T≦Ts) (NO in step S2), the control unit 20 repeats the determination in step S2. If the elapsed time (T) has exceeded the sleep transition time (Ts) (T>Ts) (YES in step S3), the control unit 20 executes control to transition the image forming apparatus 1 to sleep mode (step S4).

[0036] When the control unit 20 determines that a job has been received (YES in step S2), it executes the printing process described above (step S5). While the printing process is being executed, the control unit 20 receives detection results from the detection unit 25 at predetermined time intervals, and determines whether or not there is a transport failure (jam) of the paper M based on the detection results of the detection unit 25 (step S6).

[0037] <Normal time> If the detection result of the detection unit 25 does not indicate the occurrence of a jam, that is, if the detection is normal (NO in step S6), the control unit 20 continues the printing process until the received job is completed (NO in step S7). If the received job is completed (YES in step S7), the control unit 20 waits until the next job is received.

[0038] <When a jam occurs> If the detection result of the detection unit 25 indicates the occurrence of a jam (YES in step S6), the control unit 20 interrupts the printing process and estimates that contaminated ink 99 has adhered to the conveyance area side A1 of the conveyor belt 15 (see also FIG. 4). In other words, the control unit 20 estimates that the detection of poor conveyance of the paper M on the conveyor belt 15 indicates the occurrence of contamination on the conveyor belt 15. In this way, the control unit 20 functions as an estimation unit that estimates the contamination of the conveyor belt 15 through the determination process in step S5 using the detection result of the detection unit 25. Note that "conveyor belt 15 becoming contaminated" does not only mean that contaminated ink 99 has adhered to the surface of the conveyor belt 15 due to the occurrence of a jam, but also means that paper fragments, dust, etc. have adhered to the surface of the conveyor belt 15 in addition to the contaminated ink 99.

[0039] If it is estimated that the conveying belt 15 is contaminated with contaminating ink 99 or the like, the control unit 20 controls the charger moving unit 22 and the cleaning moving unit 24 to execute cleaning preparation control, which moves the charge roller 21 away from the conveying belt 15 and brings the tip of the cleaning member 23 into contact with the conveying belt 15 (step S8). As shown in FIG. 5, in the cleaning preparation control, the charger moving unit 22 moves the charge roller 21, which is disposed at the charge contact position P1, to the charge separation position P2, and the cleaning moving unit 24 moves the cleaning member 23, which is disposed at the cleaning separation position P4, to the cleaning contact position P3.

[0040] Next, the control unit 20 controls the transport moving unit 17 to execute jam processing preparation control to move the contaminated ink 99 on the conveyor belt 15 (step S9). As shown in FIG. 6, in the jam processing preparation control, the transport moving unit 17 rotates the conveyor belt 15 (see the arrow in FIG. 6) and moves the contaminated ink 99 located on the conveyor region side A1 of the conveyor belt 15 to the cleaning region side A2. Specifically, the transport moving unit 17 positions the contaminated ink 99 located on the conveyor region side A1 of the conveyor belt 15 upstream (above) in the rotation direction relative to the cleaning member 23 on the cleaning region side A2. In other words, the contaminated ink 99 adhering to the conveyor belt 15 is positioned slightly upstream (above) in the rotation direction from the position on the conveyor belt 15 where the tip of the cleaning member 23 contacted the conveyor belt 15. In this state, the transport moving unit 17 (conveyor belt 15) is stopped, and the contaminated ink 99 is not removed from the conveyor belt 15.

[0041] Next, the control unit 20 displays information indicating the occurrence of a jam and information prompting the user to clear the jam on an operation panel provided in the image forming apparatus 1 (step S10). The user opens the cover of the housing 2 and removes the jammed paper M (executing jam clearance). In this manner, the charging roller 21 is positioned at the charger separation position P2, the cleaning member 23 is positioned at the cleaning contact position P3, and the dirt on the conveyor belt 15 is positioned upstream of the cleaning member 23 in the rotation direction, and the paper M that has become unsuccessful is removed (see FIG. 7). In addition to displaying information on the operation panel, the control unit 20 may also emit a beep or the like from a speaker (not shown) provided in the image forming apparatus 1. The image forming apparatus 1 is also provided with an opening / closing sensor (not shown) that detects whether the cover is open or closed, and the opening / closing sensor sends a detection signal indicating the opening or closing of the cover to the control unit 20.

[0042] The control unit 20 waits until the paper M that has failed to be conveyed is removed (NO in step S11). When the user removes the paper M that has failed to be conveyed and closes the cover of the housing 2, the control unit 20 determines that "jam clearance is complete" based on the detection result of the open / close sensor (YES in step S11).

[0043] After the jam processing is completed, the control unit 20 again controls the transport moving unit 17 to execute cleaning control to remove the contaminated ink 99 on the conveyor belt 15 (step S12). As shown in FIG. 7, in the cleaning control, the transport moving unit 17 further rotates the conveyor belt 15, causing the cleaning member 23 to remove the dirt (contaminated ink 99) on the conveyor belt 15. The control unit 20 rotates the conveyor belt 15 for a predetermined time (or a predetermined angle). The contaminated ink 99 adhering to the conveyor belt 15 is scraped off the conveyor belt 15 by the cleaning member 23, and is collected in a waste container via the cleaning member 23 and a waste tube.

[0044] After the cleaning control is completed, the control unit 20 controls the charger moving unit 22 and the cleaning moving unit 24 to bring the charge roller 21 into contact with the conveyor belt 15 (to move it to the charger contact position P1) and to separate the cleaning member 23 from the conveyor belt 15 (to move it to the cleaning separation position P4) (step S13 (see FIG. 1)). Thereafter, the control unit 20 resumes the printing process (step S5).

[0045] The time and angle for driving the transport moving unit 17, the charging moving unit 22, the cleaning moving unit 24, etc. are set experimentally and empirically while taking into consideration the circumferential length and circumferential speed of the transport belt 15, and are stored in the memory of the control unit 20. In addition, various other parameters required for cleaning the transport belt 15 are also stored in the memory of the control unit 20.

[0046] In the image forming apparatus 1 according to the present embodiment described above, when the control unit 20, functioning as an estimation unit, estimates that the conveyance belt 15 is contaminated, the charger moving unit 22 moves the charge roller 21 from the charger contact position P1 to the charger separation position P2, the cleaning moving unit 24 moves the cleaning member 23 from the cleaning separation position P4 to the cleaning contact position P3, and the conveyance moving unit 17 moves the contaminant ink 99 on the conveyance belt 15 to the cleaning area A2. In this case, the conveyance moving unit 17 positions the contaminated ink 99 adhering to the conveyance belt 15 upstream of the cleaning member 23 in the rotation direction within the cleaning area A2. With this configuration, in the state shown in FIG. 6 , the contaminated ink 99 moving downward along the surface of the conveyance belt 15 can be blocked by the cleaning member 23. This prevents the contaminated ink 99 from falling from the conveyance belt 15, thereby reducing contamination inside the image forming apparatus 1 (housing 2) caused by jam clearance. Furthermore, this configuration eliminates the need for a large-scale mechanism for oscillating the conveyor belt 15 or the need to provide space inside the housing 2 for oscillating the conveyor belt 15, making it possible to reduce the size of the image forming device 1 (housing 2).

[0047] Furthermore, in the image forming apparatus 1 according to this embodiment, jam clearance is performed when the contaminated ink 99 adhering to the conveyor belt 15 is located upstream of the cleaning member 23 in the rotation direction, and then, as the conveyor belt 15 continues to rotate, the cleaning member 23 removes the contaminated ink 99 adhering to the conveyor belt 15. With this configuration, the time from the occurrence of a jam until jam clearance can be started can be shortened compared to when the cleaning member 23 removes the contaminated ink 99 on the conveyor belt 15 and then the user is asked to carry out jam clearance. This improves the convenience of jam clearance.

[0048] Furthermore, in the image forming apparatus 1 according to this embodiment, when the detection unit 25 detects a transport failure of the paper M, the control unit 20 estimates the adhesion of contaminated ink 99 on the transport belt 15. With this configuration, it is possible to simply and accurately estimate the contamination of the transport belt 15 based on the detection result of the detection unit 25.

[0049] In the image forming apparatus 1 according to the present embodiment, the charging roller 21 is provided so as to be movable in the vertical direction, and the cleaning member 23 is provided so as to be movable in the horizontal direction, but the present invention is not limited to this. For example, the charging roller 21 may be provided so as to be movable in the horizontal direction or in an oblique direction (a direction inclined relative to the vertical and horizontal directions) (not shown). Furthermore, the cleaning member 23 may be provided so as to be movable in the vertical direction or in an oblique direction (not shown).

[0050] [Variations] Next, various modified examples of the image forming apparatus 1 according to this embodiment will be briefly described with reference to Figs. 8 to 10. Fig. 8 is a schematic diagram (front view) showing the internal structure of the image forming apparatus 1 according to a first modified example. Fig. 9 is a schematic diagram (front view) showing the internal structure of the image forming apparatus 1 according to a second modified example. Fig. 10 is a flowchart showing the operating procedure (method of cleaning the conveyor belt) of the belt cleaning structure of the image forming apparatus according to a third modified example. Note that the same components as those of the image forming apparatus 1 according to this embodiment described above are assigned the same reference numerals, and their description will be omitted.

[0051] <First Modification> In the image forming apparatus 1 described above, the conveyor belt 15 is positioned in a substantially upright position, and a vertical conveyance system is employed in which the paper M is conveyed vertically upward. However, the present invention is not limited to this. For example, as shown in FIG. 8 , the conveyor belt 15 may be positioned in an inclined position, and the paper M may be conveyed diagonally upward from below (first modified example). In this case, the charging roller 21 and the cleaning member 23 may be provided so as to be movable in the vertical direction, the horizontal direction, or an oblique direction (a direction inclined relative to the vertical and horizontal directions) (not shown). The angle of inclination of the conveyor belt 15 relative to a line extending vertically can be freely set.

[0052] <Second Modification> In the image forming apparatus 1 according to the first modification, when the conveyor belt 15 is configured to convey the paper M obliquely upward, there is a risk that the contaminated ink 99 may fall off the top of the conveyor belt 15 as it is moved from the conveying region A1 to the cleaning region A2. Therefore, as shown in FIG. 9 , in the image forming apparatus 1 according to the second modification, when the conveyor belt 15 conveys the paper M obliquely upward, the cleaning member 23 is provided so as to be able to contact the top of the conveyor belt 15 on the cleaning region A2 (the portion facing the tension roller 16A). With this configuration, when the contaminated ink 99 adhering to the conveyor belt 15 is moved from the conveying region A1 to the cleaning region A2, the cleaning member 23 can catch the contaminated ink 99 that attempts to fall off the top of the conveyor belt 15 as it is being moved from the conveying region A1 to the cleaning region A2. This prevents the interior of the image forming apparatus 1 from being contaminated by the contaminated ink 99 that has fallen off the conveyor belt 15.

[0053] <Third Modification> In the image forming apparatus 1 according to the present embodiment (including the first and second modified examples), as shown in FIG. 3, before jam clearance is performed, the transport moving unit 17 positions the contaminated ink 99 adhering to the conveyor belt 15 upstream of the cleaning area A2 in the rotation direction of the cleaning member 23 (step S9). After the jam clearance is completed (YES in step S11), the transport moving unit 17 causes the conveyor belt 15 to rotate further and the cleaning member 23 removes (cleans) the contaminated ink 99 (step S12). However, the present invention is not limited to this. For example, as shown in FIG. 10, instead of step S9, before jam clearance is performed, the control unit 20 may control the transport moving unit 17 to rotate the conveyor belt 15 so that the cleaning member 23 removes (cleans) the contaminated ink 99 (step S9' (third modified example)). In this case, step S12 is omitted, and the control unit 20 executes step S13 after the jam clearance is completed (YES in step S11). According to this configuration, printing can be resumed quickly after jamming has been cleared.

[0054] In the image forming apparatus 1 according to the present embodiment (including the first to third modified examples, the same applies below), one detection unit 25 is provided to detect jams, but the present invention is not limited to this. For example, two detection units 25 may be provided, one on the upstream side and one on the downstream side of the conveyor belt 15 (not shown). In this case, the control unit 20 may determine that the operation is normal if the time from when the upstream detection unit 25 detects the sheet M until when the downstream detection unit 25 detects the sheet M is within a set time, and may determine that a jam has occurred if the time exceeds the set time.

[0055] In the image forming apparatus 1 according to the present embodiment, the transport moving section 17, the charging moving section 22, the cleaning moving section 24, etc. are controlled by the control section 20 that performs overall control, but the present invention is not limited to this. For example, a dedicated control means (not shown) that controls the transport moving section 17, the charging moving section 22, the cleaning moving section 24, etc. may be provided separately from the control section 20.

[0056] Furthermore, in the image forming apparatus 1 according to the present embodiment, the head unit 12 includes four line heads 13, but this is not limiting and the head unit 12 may include one or more line heads 13. Furthermore, although three recording heads 14 are mounted on one line head 13, this is not limiting and the head unit 12 may include one or more recording heads 14.

[0057] Furthermore, the image forming apparatus 1 according to the present embodiment is a color printer, but is not limited to this and may be a monochrome printer, a copier, a facsimile, or the like.

[0058] The above-described embodiment shows one aspect of the image forming apparatus according to the present invention, and the technical scope of the present invention is not limited to the above-described embodiment. The present invention may be variously changed, substituted, or modified without departing from the spirit of the technical concept, and the claims include all embodiments that may fall within the scope of the technical concept. [Explanation of symbols]

[0059] 1. Image forming device 14 Recording head (recording unit) 15 Conveyor belt 17 Transport moving section 20 Control unit (estimation unit) 21 Charging roller 22 Charge transfer section 23 Cleaning materials 24 Cleaning Mobile Department 25 Detection unit 99 Contaminated ink (dirt) A1 Conveying area side A2 Cleaning area side M Paper (medium) P1 Charge contact position P2 Charge separation position P3 Cleaning contact position P4 Cleaning distance position

Claims

1. a recording unit that ejects liquid toward a medium; a conveyor belt that faces the recording unit and conveys the medium vertically upward or obliquely upward; a conveying and moving unit that rotates the conveying belt; a charging roller that contacts the rotating conveyor belt and charges the conveyor belt; a charge transfer unit that transfers the charging roller between a charge contact position where the charging roller is in contact with the conveyor belt and a charge separation position where the charging roller is separated from the conveyor belt; a cleaning member that comes into contact with a cleaning area of ​​the rotating conveyor belt, the cleaning area being opposite to a conveyor area facing the recording unit, and cleans the conveyor belt; a cleaning movement unit that moves the cleaning member between a cleaning contact position where the cleaning member is in contact with the conveyor belt and a cleaning separation position where the cleaning member is separated from the conveyor belt; an estimation unit that estimates the degree of contamination of the conveyor belt, An image forming apparatus characterized in that, when the estimation unit estimates that the conveying belt is dirty, the charging transfer unit moves the charging roller positioned at the charging contact position to the charging separation position, the cleaning transfer unit moves the cleaning member positioned at the cleaning separation position to the cleaning contact position, and the conveying transfer unit rotates the conveying belt to move dirt positioned on the conveying area side of the conveying belt to the cleaning area side.

2. The image forming apparatus of claim 1, characterized in that when the estimation unit estimates that the conveying belt is dirty, the conveying movement unit rotates the conveying belt and positions the dirt located on the conveying area side of the conveying belt upstream of the cleaning member in the rotation direction on the cleaning area side.

3. the estimation unit estimates that detection of a transport failure of the medium on the transport belt indicates occurrence of contamination on the transport belt; The image forming apparatus of claim 2, characterized in that when the estimation unit estimates that the conveying belt is dirty, the charging roller is positioned at the charge separation position, the cleaning member is positioned at the cleaning contact position, and the dirt on the conveying belt is positioned upstream of the cleaning member in the rotation direction, and the medium that has become poorly conveyed is removed, and then the conveying movement unit further rotates the conveying belt, causing the cleaning member to remove the dirt on the conveying belt.

4. 4. The image forming apparatus according to claim 1, wherein the cleaning member is capable of contacting an upper portion of the conveyor belt on the cleaning area side.

5. a detection unit that is provided upstream of the recording unit in the transport direction of the medium and that detects a transport failure of the medium on the transport belt; 4. The image forming apparatus according to claim 1, wherein the estimation unit estimates that the transport belt is dirty when the detection unit detects the transport failure of the medium.

Images