JP7341848B2 - Conveyance device - Google Patents

Description

The present invention relates to a conveyance device that conveys paper.

For example, in a printing device that prints by ejecting ink from an inkjet head onto printing paper transported from a paper feed unit, a jam (paper jam) may occur in the transported paper. In such a case, it is necessary to stop the apparatus and remove the paper remaining due to the occurrence of the jam (hereinafter referred to as "residual paper"). As printing apparatuses having a function of removing such residual paper, for example, those disclosed in Patent Documents 1 and 2 are known.

Patent Document 1 discloses that when there is residual paper on a belt platen that conveys paper to a printing position by an inkjet head, the remaining paper is brought up against a guide plate to lift the paper from the conveyance surface of the belt platen. It is disclosed that the suction force of air suction is weakened to make it easier to remove residual paper.

Patent Document 2 discloses that when a jam is detected on the belt platen, the belt platen is tilted and the remaining paper is conveyed to a dedicated holder.

Japanese Patent Application Publication No. 2016-132513 Japanese Patent Application Publication No. 2009-160778

However, in Patent Document 1, when the remaining paper on the belt platen is manually removed, the remaining paper may come into contact with the surface of the ink ejection part of the inkjet head, especially in the case of large size paper such as A3 paper. However, there is a problem in that the meniscus of the inkjet head is disturbed and the printing performance is deteriorated. Further, in the device disclosed in Patent Document 2, it is necessary to separately install a mechanism for tilting the belt platen, which causes a problem that the device configuration becomes large-scale.

The present invention has been made in order to solve such conventional problems, and its purpose is to remove residual paper remaining in the printing conveyance section without damaging the inkjet head and to increase the size of the inkjet head. The object of the present invention is to provide a conveying device that can be easily removed without any problems.

In order to achieve the above object, a conveyance device according to the present invention includes a print conveyance section that conveys paper below an inkjet head, and a conveyance section that conveys the paper along a conveyance path passing through the print conveyance section. , the print conveyance unit is positioned between a print position, which is a position where the inkjet head is printing, and an intermediate position, which is a position below the print position and where a predetermined space exists below the print conveyance unit. an ink pan that receives ink that falls from the ink jet head during maintenance of the ink jet head; and an ink pan that is provided in the ink pan and that guides residual paper sent to the predetermined space by the printing conveyance unit. a guide member; and a control unit that controls the transport unit to stop transporting the paper when a paper jam occurs in the transport path during printing by the inkjet head, and the control unit controls the printing After the conveyance unit is lowered from the print position to the intermediate position, the print conveyance unit is controlled to send out the remaining paper in the print conveyance unit to the predetermined space.

According to the conveyance device according to the present invention, it becomes possible to easily remove residual paper remaining in the printing conveyance section without damaging the inkjet head and without increasing the size of the inkjet head.

FIG. 1 is a schematic configuration diagram showing a printing device to which a conveyance device according to an embodiment of the present invention is applied. FIG. 2 is a control block diagram showing the electrical configuration of a printing device to which a conveyance device according to an embodiment of the present invention is applied. FIG. 3A is an explanatory diagram showing the state when the belt platen is in the printing position. FIG. 3B is an explanatory diagram showing the state when the belt platen is at an intermediate position. FIG. 3C is an explanatory diagram showing the situation when the belt platen is at the lower limit position. FIG. 4 is a flowchart showing the processing operation of the transport device according to the first embodiment of the present invention. FIG. 5A is a first explanatory diagram showing how the remaining paper remaining on the belt platen is sent out. FIG. 5B is a second explanatory diagram showing how the remaining paper remaining on the belt platen is sent out. FIG. 5C is a third explanatory diagram showing how the remaining paper remaining on the belt platen is sent out. FIG. 6 is an explanatory diagram showing a lifting sensor provided on a belt platen of a conveyance device according to a second embodiment of the present invention. FIG. 7 is an explanatory diagram showing the operation of the uplift sensor, in which (a) shows how the sheet comes into contact with the swinging section, and (b) shows how the swinging section swings. FIG. 8 is a flowchart showing the processing operation of the transport device according to the second embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. The same or equivalent parts and components are designated by the same or equivalent symbols throughout the drawings.

The embodiments shown below exemplify devices etc. for embodying the technical idea of this invention, and the technical idea of this invention is based on the material, shape, structure, arrangement, etc. of each component. It is not specific to the following. The technical idea of this invention can be modified in various ways within the scope of the claims.

[Description of the first embodiment]
FIG. 1 is an explanatory diagram schematically showing the configuration of a printing device that employs a conveyance device according to a first embodiment of the present invention. FIG. 2 is a control block diagram of the printing apparatus 1 shown in FIG. 1. In the following description, the direction perpendicular to the paper surface of FIG. 1 will be referred to as the front-rear direction, and the front direction of the paper surface will be referred to as the front direction. Moreover, the top, bottom, left and right of the paper surface in FIG. 1 are defined as the top, bottom, left and right directions.

In FIG. 1, the route indicated by the thick line is the conveyance route along which paper, which is a printing medium, is conveyed. Among the conveyance routes, the route shown with a solid line is the printing route RP, the route shown with a dashed-dotted line is the circulation route RC, the route shown with a dashed line is the paper discharge route RD, and the route shown with a chain double-dashed line is the external paper feeding route RS1 and the internal paper feeding route. The route is RS2. Upstream and downstream in the following description mean upstream and downstream in the transport route.

As shown in FIGS. 1 and 2, the printing apparatus 1 according to the first embodiment includes a paper feed section 2, a belt platen transport section 3, a printing section 4, a circulation transport section 5, and a paper discharge section 6. , an operation panel 7, a control section 8, an ink pan 10, and a housing 9 that houses or holds each section. Note that the paper feed section 2, belt platen conveyance section 3, printing section 4, circulation conveyance section 5, and paper discharge section 6 transport paper along the above-mentioned conveyance path via the belt platen 26 (print conveyance section), which will be described later. Configures a conveying section for conveying.

The paper feed section 2 feeds unprinted paper P to the belt platen transport section 3 . Further, the paper feeding section 2 refeeds the paper P after single-sided printing to the belt platen conveying section 3 during double-sided printing. The paper feed section 2 is arranged at the most upstream side of the conveyance path. The paper feed unit 2 includes an external paper feed tray 11, an external paper feed roller 12, internal paper feed trays 13A and 13B, internal paper feed rollers 14A and 14B, internal paper feed conveyance rollers 16A to 16C, and a vertical conveyance roller. It includes a roller 18, a registration roller 20, and paper sensors 22 to 24.

The external paper feed tray 11 loads paper P used for printing, and the external paper feed roller 12 takes out the stacked paper P one by one and conveys it toward the registration rollers 20 along the external paper feed path RS1. do.

The internal paper feed trays 13A, 13B load sheets P used for printing, and the internal paper feed rollers 14A, 14B take out the sheets P stacked on the internal sheet feed trays 13A, 13B one by one.

Internal paper feed conveyance rollers 16A, 16B, and 16C convey paper P taken out by internal paper feed rollers 14A and 14B, respectively, to vertical conveyance roller 18.

The vertical conveyance roller 18 conveys the paper P conveyed from the internal paper feed conveyance roller 16C along the internal paper feed path RS2 to the registration rollers 20. Further, the vertical conveyance rollers 18 convey the sheet P after single-sided printing, which has been circulated and conveyed along the circulation path RC during double-sided printing, to the registration rollers 20 .

The registration rollers 20 temporarily stop the paper P conveyed by the external paper feed roller 12 or the vertical conveyance roller 18 to correct the skew, and then convey it to a belt platen 26 (print conveyance unit), which will be described later.

The paper sensors 22 and 23 detect the paper P taken out from the internal paper feed trays 13A and 13B and conveyed to the registration rollers 20. The paper sensor 24 detects the paper P that is conveyed by the external paper feed roller 12 or the vertical conveyance roller 18 and enters the registration rollers 20 .

The belt platen conveyance section 3 conveys the paper P conveyed from the paper feed section 2 to the circulation conveyance section 5 or the paper discharge section 6. The belt platen conveying section 3 is arranged downstream of the paper feeding section 2. The belt platen transport unit 3 includes a belt platen 26 (print transport unit) and a paper sensor 28.

The belt platen 26 includes a rotating annular conveyance belt, and conveys the paper P conveyed by the registration rollers 20 by sucking and holding the paper P on the conveyance belt by air suction.

The belt platen 26 can be raised and lowered in the vertical direction between a printing position, a lower limit position, and an intermediate position by a lifting drive unit 32, which will be described later. That is, the distance between the head unit 31 and the belt platen 26 can be changed. The printing position is the position of the belt platen 26 during printing by the printing unit 4. The printing position is the position of the belt platen 26 shown in FIG. 1, and is located near the bottom of the inkjet head 36. The lower limit position is the position where the belt platen 26 is lowered to the maximum extent. The lower limit position is below the printing position and near the upper side of a lower conveyance roller 51, which will be described later. The intermediate position is located between the print position and the lower limit position. Therefore, when the belt platen 26 moves to the intermediate position, a predetermined space exists between the belt platen 26 and the lower conveyance section 43 (see reference numeral 73 in FIG. 3B, which will be described later).

Paper sensor 28 detects paper P conveyed from registration rollers 20 to belt platen 26 .

The printing unit 4 prints on paper P. The printing section 4 is arranged above the belt platen 26. The printing section 4 includes a head unit 31 and an elevation drive section 32.

The head unit 31 prints an image by ejecting ink onto the paper P conveyed by the belt platen 26. The head unit 31 includes a plurality of inkjet heads 36 and a head holder 37.

The inkjet head 36 has a plurality of nozzles arranged along the front-rear direction (main scanning direction), and ejects ink from the nozzles. The plurality of inkjet heads 36 are arranged in parallel along the conveyance direction (horizontal direction) of the paper P.

The head holder 37 holds the inkjet head 36. The head holder 37 is fixed at a predetermined position within the housing 9.

The elevating drive unit 32 moves the belt platen 26 up and down between a printing position, a lower limit position, and an intermediate position. The elevating drive section 32 is arranged within the head holder 37. The lift drive unit 32 includes wires, pulleys, motors, etc., and suspends and supports the belt platen 26 by the wires. The lifting drive section 32 moves the belt platen 26 up and down by rotating a pulley using a motor to wind up and unwind the wire.

The circulation conveyance section 5 conveys the paper P after single-sided printing during double-sided printing from the downstream end of the belt platen 26 to the vertical conveyance roller 18 along the circulation path RC. The circulation conveyance section 5 includes an intermediate conveyance section 41 , a reversing section 42 , a lower conveyance section 43 , and an ascending conveyance section 44 .

The intermediate conveyance section 41 conveys the paper P after single-sided printing from the belt platen 26 to the reversing section 42 during double-sided printing. The intermediate conveyance section 41 includes two pairs of intermediate conveyance rollers 46 and a paper sensor 48.

The intermediate conveyance roller 46 receives the sheet P after single-sided printing sent out from the belt platen 26, and conveys it to a reversing roller 49, which will be described later. The paper sensor 48 detects the paper P conveyed by the intermediate conveyance roller 46 to the reversing roller 49 .

The reversing unit 42 includes a reversing roller 49 that switches back the sheet P after single-sided printing that has been transported by the intermediate transport roller 46 .

The lower conveyance section 43 is disposed below the belt platen 26 and conveys the paper P from the reversing section 42 to the ascending conveyance section 44 . The lower conveyance section 43 includes three pairs of lower conveyance rollers 51 and paper sensors 53 and 54.

The lower conveyance roller 51 conveys the paper P switched back by the reversing roller 49 to the ascending conveyance roller 56 . A space is provided between the lower conveyance section 43 and the belt platen 26 when the belt platen 26 moves up and down. Among these, the space between the lower end of the belt platen 26 and the lower conveyance section 43 when the belt platen 26 is lowered to the above-mentioned intermediate position is the above-mentioned "predetermined space" (see reference numeral 73 in FIG. 3B). ).

The paper sensors 53 and 54 detect the paper P that is conveyed to the vertical conveyance roller 18 along the circulation path RC after being switched back by the reversing roller 49 .

The ascending conveyance section 44 includes an ascending conveyance roller 56 that conveys the paper P conveyed from the lower conveyance roller 51 to the vertical conveyance roller 18 .

The paper discharge unit 6 discharges the printed paper P. The paper ejection section 6 includes a switching section 61 , three pairs of paper ejection rollers 63 , paper sensors 65 and 66 , and a paper ejection tray 67 .

The switching unit 61 switches the transport route of the paper P between the paper discharge route RD and the circulation route RC. The paper discharge roller 63 receives the paper P conveyed from the belt platen 26 and discharges the paper onto the paper discharge tray 67 . Paper sensors 65 and 66 detect paper P conveyed along paper discharge path RD. The paper ejection tray 67 is used to stack the paper P ejected by the paper ejection roller 63.

The operation panel 7 displays various input screens and the like, and also accepts input operations from the user. As shown in FIG. 2, the operation panel 7 includes a display section 71 such as a liquid crystal display, and an input section 72 such as a touch panel or operation keys.

The control section 8 controls the operation of each section of the printing apparatus 1. The control unit 8 includes a CPU, RAM, ROM, hard disk, and the like.

Specifically, the control unit 8 feeds the paper P to the belt platen 26 by the paper feed unit 2, and prints on the paper P by discharging ink from the inkjet head 36 while conveying the paper P by the belt platen 26. control so that In the case of double-sided printing, the control section 8 causes the circulation conveyance section 5 to turn over the sheet P after single-sided printing and convey it to the vertical conveyance rollers 18 of the paper feed section 2, and then transfer the paper P to the belt platen using the vertical conveyance rollers 18 and the registration rollers 20. Control is performed so that the paper is re-fed to 26 and printed on the unprinted surface. The control unit 8 controls the paper discharge unit 6 to discharge the printed paper P.

The control unit 8 determines whether or not a jam has occurred in the paper being conveyed based on the detection results from the paper sensors 22 to 24, 28, 48, 53, 54, 65, and 66. Specifically, the control unit 8 detects a paper jam when the detection timing of the paper P in at least one of the paper sensors 22 to 24, 28, 48, 53, 54, 65, and 66 is delayed by more than a threshold value than the theoretical value. It is determined that this has occurred.

If a paper jam occurs during a printing operation, the control unit 8 stops conveyance of the paper by the belt platen 26, and further stops suction by air. The control section 8 further drives the lift drive section 32 to lower the belt platen 26 from the printing position to the intermediate position. As will be described later, the control unit 8 starts conveyance by the belt platen 26 and discharges the remaining paper placed on the belt platen 26 below the belt platen 26.

The control section 8 lowers the belt platen 26 to the lower limit position when inspecting or maintaining the belt platen conveying section 3 or the printing section 4. The control unit 8 further protects the belt platen 26 by moving an ink pan 10, which will be described later, to be interposed above the belt platen. Note that the ink pan 10 is also sometimes referred to as a "maintenance pan."

When maintaining the head unit 31, the ink pan 10 is interposed between the head unit 31 and the belt platen 26, and receives ink falling from the inkjet head 36 with a receiving surface, so that the ink reaches the belt platen 26. Prevents adhesion. Alternatively, the ink pan 10 includes a wiper unit (not shown) for cleaning the inkjet head 36, and the tip of the inkjet head 36 is cleaned by operating the wiper unit periodically or as needed. Further, as shown in FIGS. 3A to 3C, which will be described later, a guide member 74 having a curved surface for guiding paper conveyance is provided on the back surface of the ink pan 10, that is, the surface opposite to the surface that receives ink. It is being

3A, 3B, and 3C are explanatory diagrams showing the positional relationship between the belt platen 26 and the ink pan 10. FIG. 3A shows when the belt platen 26 is in the printing position, and FIG. 3B shows that the belt platen 26 is in the intermediate position. 3C shows the belt platen 26 at the lower limit position.

As shown in FIG. 3A, when printing is performed by the head unit 31 and the belt platen 26 is in the printing position, the ink pan 10 is tilted to the side below the belt platen 26, that is, with respect to the horizontal plane. It is placed in an inclined position (retracted position).

As shown in FIG. 3C, during maintenance of the head unit 31, the belt platen 26 is lowered to the lower limit position, and the ink pan 10 is interposed between the head unit 31 and the belt platen 26 ( position). Therefore, when ink falls from the inkjet head 36, the receiving surface of the ink pan 10 can receive the ink, thereby preventing the ink from adhering to the belt platen 26.

Further, if a jam occurs in the paper being conveyed on the belt platen 26, the belt platen 26 is lowered to an intermediate position as shown in FIG. 3B. Therefore, a predetermined space 73 exists between the belt platen 26 and the lower conveyance section 43 (see FIG. 1) located below. Further, as shown in FIG. 3B, when the belt platen 26 is lowered to the intermediate position, the guide member 74 formed on the back surface of the ink pan 10 is located exactly near the paper ejection position of the belt platen 26. Therefore, the remaining paper conveyed by the belt platen 26 is guided by the curved surface formed on the guide member 74 and sent out to a predetermined space 73 of the belt platen 26.

[Description of the operation of the first embodiment]
Next, the operation of the printing device 1 will be explained.

When a print job is input, the control unit 8 executes a printing operation. The control unit 8 acquires single-sided/double-sided printing setting information included in the print job, and executes single-sided printing or double-sided printing depending on the content.

In the case of single-sided printing setting, the control unit 8 controls the paper feed unit 2 to take out unprinted paper P from either the external paper feed tray 11 or the internal paper feed trays 13A, 13B, and sequentially feed the sheets to the belt platen 26. Control. The control unit 8 controls the paper feeding unit 2 to sequentially feed the sheets P at a timing such that each sheet P is conveyed at a predetermined interval on the belt platen 26. As a result, a plurality of sheets of paper P are simultaneously transported on the transport path.

The fed paper P is printed with ink ejected from the inkjet head 36 while being transported at a predetermined print transport speed on the belt platen 26 . Here, the belt platen 26 is placed at the printing position. The printed paper P is guided to the paper discharge path RD by the switching unit 61, is conveyed by the paper discharge roller 63, and is discharged to the paper discharge tray 67.

In the case of double-sided printing setting, the control unit 8 sequentially feeds unprinted sheets P at timings where the time between feeding timings of each sheet P is twice the feeding timing for single-sided printing. Controls the paper feed section 2.

The fed paper P is printed while being conveyed by the belt platen 26 disposed at the printing position, as in the case of single-sided printing. The paper P after single-sided printing is guided to the circulation path RC by the switching unit 61 and is transported to the reversing roller 49 by the intermediate transport roller 46 . Upon reaching the reversing roller 49, the paper P is switched back by the reversing roller 49. Next, the paper P after single-sided printing is conveyed to the vertical conveyance roller 18 by the lower conveyance roller 51 and the upward conveyance roller 56 . The paper P after single-sided printing is then re-fed to the belt platen 26 by the vertical conveyance rollers 18 and the registration rollers 20.

Here, the sheets P after single-sided printing are re-fed at a timing such that they are sent to the belt platen 26 alternately with unprinted sheets P that are sequentially fed. As described above, in double-sided printing, the time between paper feeding timings for each sheet P is twice as long as the paper feeding timing in single-sided printing. Therefore, it is possible to insert the paper P after one-sided printing between the unprinted papers P, and re-feed the paper P after one-sided printing alternately with the feeding of the unprinted paper P. .

The paper P after single-sided printing is switched back by the reversing roller 49 and is sent to the belt platen 26 with the unprinted side facing upward. After single-sided printing, the sheet P is conveyed by the belt platen 26 and printed on the unprinted side. Then, the paper P on which double-sided printing has been printed is guided to the paper discharge path RD by the switching unit 61, conveyed by the paper discharge roller 63, and discharged to the paper discharge table 67.

As described above, in double-sided printing, the unprinted paper P is fed and the paper P after single-sided printing is fed again, so that one side of the unprinted paper P is fed on the belt platen 26. Printing on one side and printing on the unprinted side of paper P after single-sided printing are performed alternately. As a result, double-sided printing can be performed with the same productivity per single side as when printing on one side.

During single-sided printing or double-sided printing as described above, the control unit 8 determines whether a paper jam has occurred. Specifically, the control unit 8 detects a paper jam when the detection timing of the paper P in at least one of the paper sensors 22 to 24, 28, 48, 53, 54, 65, and 66 is delayed by more than a threshold value than the theoretical value. It is determined that this has occurred.

Processing when a jam occurs will be described below with reference to the flowchart shown in FIG. If it is determined that a paper jam has occurred (YES in step S11), the control unit 8 stops the paper feeding unit 2, the belt platen transport unit 3, the circulation transport unit 5, and the paper discharge unit 6 from transporting the paper. Furthermore, suction by air is stopped (step S12).

Next, the control unit 8 determines whether there is any jammed remaining paper on the conveyance path of the belt platen 26 based on the detection result by the paper sensor 28 (step S13). If there is no remaining paper (NO in step S13), this process ends. If there is any remaining paper (YES in step S13), the control section 8 drives the lift drive section 32 to lower the belt platen 26 to the intermediate position (step S14). That is, it is lowered to the position shown in FIG. 3B.

The control unit 8 starts suctioning the belt platen 26 with air, and also starts transporting the remaining paper (step S15).

The control unit 8 determines whether the belt platen 26 has been conveyed a predetermined distance (step S16). For example, it is determined whether or not the belt platen 26 has been conveyed one revolution.
If the object has been transported a predetermined distance (YES in step S16), the control unit 8 releases the interlock of the front door (not shown) of the housing 9 (step S17). Furthermore, a process is performed to notify the user of the occurrence of a jam and the location of the remaining paper on the display unit 71 (see FIG. 2). The user can open the front door of the housing 9 and easily take out the remaining paper.

5A, FIG. 5B, and FIG. 5C are explanatory diagrams showing the flow of residual paper discharged from the belt platen 26. If there is any remaining paper on the conveyance path of the belt platen 26, the remaining paper is delivered to a predetermined space 73 in the order of FIGS. 5A, 5B, and 5C.

Specifically, the remaining paper P1 existing on the conveyance path of the belt platen 26 is conveyed rightward in the figure, as shown in FIG. 5A, and hits the curved surface of the guide member 74 formed on the back side of the ink pan 10. Next, as shown in FIG. 5B, the discharge direction of the remaining paper P1 is regulated by a guide member 74, and the remaining paper P1 is sent to a space 73 (predetermined space) located below the belt platen 26. As shown in FIG. 5C, the remaining paper P1 is accumulated in the space 73 of the belt platen 26.

The user can easily take out the remaining paper by opening the front door of the housing 9. In this way, when a paper jam occurs during printing, the residual paper P1 left on the conveyance path of the belt platen 26 can be easily sent to the space 73 below the belt platen 26 and taken out.

[Description of effects of the first embodiment]
In this way, in the conveyance device according to the first embodiment, when a jam occurs in the paper being conveyed by the belt platen 26 (print conveyance section), conveyance by the belt platen 26 is temporarily stopped, and the conveyance by the belt platen 26 is temporarily stopped. Lower the platen 26 to an intermediate position. Thereafter, by starting conveyance by the belt platen 26 again, the remaining paper present on the conveyance path of the belt platen 26 can be delivered to a predetermined space 73 below the belt platen 26.

Therefore, the remaining paper can be transported to a position where it can be easily taken out with a simple configuration without providing any special equipment or parts. Further, since the remaining paper is accumulated in a predetermined space below the belt platen 26, the problem of the remaining paper coming into contact with the tip of the inkjet head 36 when the user takes out the remaining paper can be avoided. becomes possible. Furthermore, it is possible to avoid getting the user's hands dirty when taking out the remaining paper. Further, if the removed remaining paper is unprinted paper and is not damaged, it is possible to reuse the remaining paper.

When the belt platen 26 is lowered to the intermediate position, a guide member 74 is provided at the portion where the paper is sent out from the belt platen 26 to guide the downward delivery of the remaining paper, so that the remaining paper can be smoothly removed. It can be delivered to the space below the belt platen 26.

By attaching the guide member 74 to the back side of the ink pan 10, the remaining paper can be moved to the belt platen 26 with an extremely simple operation of attaching the guide member 74 to the back side of the ink pan 10, which has been installed conventionally. It can guide the downward delivery.

[Description of second embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment, only when a jam is detected in the paper being conveyed to the belt platen 26 and the paper is lifted (also referred to as "curl"), the residual remaining on the belt platen 26 is removed. A process for sending the paper below the belt platen 26 is carried out.

FIG. 6 is an explanatory diagram showing a partial configuration of the belt platen 26a provided in the conveying device according to the second embodiment. As shown in FIG. 6, the belt platen 26a according to the second embodiment includes a conveyor belt 81 that conveys the paper, and rollers 82 that apply pressure to the paper at a plurality of locations (only two locations are shown in the figure). There is.

A lifting detection sensor 83 is provided near the upstream end of the conveyor belt 81 to detect lifting of the leading edge of the sheet. The lifting detection sensor 83 is an example of a "lifting determination unit" that determines lifting of paper.

The uplift detection sensor 83 includes a swing sensor section 83a and a swing section 83b. The swinging portion 83b is disposed above the conveyor belt 81 by a distance x1 (see FIG. 7(a)), and when the sheet of paper conveyed on the conveyor belt 81 rises by more than the distance x1, It swings in contact with the end. The swing sensor section 83a detects when the paper comes into contact with the swing section 83b.

FIGS. 7A and 7B are explanatory diagrams showing the operation of the lifting detection sensor 83 when detecting lifting paper. When the leading edge side of the paper P2 is lifted by more than the distance x1, the leading edge side of the paper P2 comes into contact with the swinging portion 83b, as shown in FIG. 7(a). Thereafter, as shown in FIG. 7(b), the lifted paper P2 causes the swinging section 83b to swing in the upper right direction, so the swinging sensor section 83a detects the swinging of the swinging section 83b. do.

The control unit 8 shown in FIG. 2 acquires the detection result by the uplift detection sensor 83. Based on the obtained detection results, the control unit 8 executes the process shown in the first embodiment described above when the paper P2 is lifted, and when the paper P2 is not lifted, The processing shown in the first embodiment is not performed.

Hereinafter, the processing procedure by the conveying device according to the second embodiment will be explained with reference to the flowchart shown in FIG. 8. The processes shown in steps S11 to S17 shown in FIG. 8 are the same as those shown in steps S11 to S17 shown in FIG. 4 described above. The difference in FIG. 9 is that the process of step S11a is added after the process of step S11.

That is, in the second embodiment, the processes of steps S12 to S17 are executed only when a paper jam occurs and the paper is lifted.

Specifically, it is determined whether or not lifting occurs in the paper being conveyed on the conveyor belt 81 of the belt platen 26a, and only when lifting occurs, the conveyance by the belt platen 26a is stopped, and the belt The platen 26a is lowered to the intermediate position, and the belt platen 26a is driven again to send out the remaining paper remaining on the belt platen 26a below the belt platen 26a.

If the paper being conveyed on the conveyor belt 81 of the belt platen 26a does not lift up, even if you take out the residual paper remaining on the belt platen 26a, the residual paper will not reach the tip of the inkjet head 36. Problems such as contact are unlikely to occur.

Rather, by performing the process of lowering the belt platen 26a to an intermediate position and driving the belt platen 26a again, the recovery process takes a long time. In order to avoid such a problem, in the second embodiment, the process shown in the first embodiment described above is executed only when lifting occurs in the paper.

As described above, in the conveyance device according to the second embodiment, a jam occurs in the paper conveyed on the conveyance path, residual paper is present on the belt platen 26a, and the residual paper is lifted. The process shown in the first embodiment described above is executed only when there is a problem. Therefore, it is possible to avoid the problem of the remaining paper coming into contact with the tip of the inkjet head 36, and to prevent the belt platen 26a from being lowered to an intermediate position unnecessarily.

Furthermore, since the lifting of the paper is detected when the paper comes into contact with the swinging portion 83b of the lifting sensor 83, the occurrence of lifting can be detected with high accuracy.

[Description of modification of second embodiment]
In the second embodiment described above, an example has been described in which the lifting detection sensor 83 is used to detect lifting of paper. In a modified example, when performing double-sided printing in which the first side of the paper is printed and then the second side is printed, lifting occurs based on the printing rate on the first side (this is set as α). This embodiment differs from the second embodiment described above in that it is determined whether or not the current state has occurred.

When printing on one side of a sheet of paper, when ink for printing characters and figures is jetted, the sheet of paper absorbs the jetted ink, which may cause the sheet to become "warped." The magnitude of "warpage" tends to increase as the amount of ink ejected increases. In a modified example, when the printing rate α (corresponding to the amount of ink) when printing on the first side exceeds a preset threshold αth during double-sided printing, “warping” occurs in this paper, that is, the belt platen It is determined that 26a is becoming more lifted up from the conveyor belt 81.
Here, the printing rate can be the ratio of printed characters to the number of characters that can be printed on paper, or the ratio of the area covered by characters or figures to the area of the entire paper.

Therefore, the control unit 8 acquires the printing rate α on the first side of the paper on which double-sided printing is performed from the print data, and when the printing rate α exceeds the threshold value αth, Perform similar processing. By doing so, it becomes possible to determine the magnitude of the lifting occurring on the paper without installing the lifting detection sensor 83 shown in FIG. 6. The control unit 8 is an example of a “lifting determination unit” that determines lifting of the leading edge of the paper.

Thus, it goes without saying that the present invention includes various embodiments not described here. Therefore, the technical scope of the present invention is determined only by the matters specifying the invention in the claims that are reasonable from the above description. The inventions stated in the claims originally filed are added below.
[Additional note 1]
a conveyance unit that has a print conveyance unit that conveys the paper below the inkjet head, and conveys the paper along a conveyance path passing through the print conveyance unit;
The printing conveyance unit is raised and lowered between a printing position, which is a position where the inkjet head is printing, and an intermediate position, which is a position below the printing position and where a predetermined space exists below the printing conveyance unit. a lifting drive unit for
a control unit that controls the transport unit to stop transporting the paper when a paper jam occurs in the transport path during printing by the inkjet head;
The control unit includes:
A conveyance device characterized in that, after lowering the print conveyance unit from the printing position to the intermediate position, the print conveyance unit is controlled so as to send out the remaining paper in the print conveyance unit to the predetermined space.
[Additional note 2]
The conveyance device according to appendix 1, further comprising a guide member that guides the remaining paper sent to the predetermined space by the printing conveyance section.
[Additional note 3]
further comprising an ink pan that receives ink that falls from the inkjet head during maintenance of the inkjet head,
The conveying device according to appendix 2, wherein the guide member is provided on the ink pan.
[Additional note 4]
further comprising a lifting determination unit that determines lifting of the paper conveyed by the printing conveyance unit,
A supplementary note characterized in that the control unit controls to lower the printing conveyance unit to the intermediate position and send out the remaining paper to the predetermined space only when the lifting occurs. The conveyance device according to any one of 1 to 3.
[Additional note 5]
4. The conveying device according to appendix 4, wherein the lifting determination unit is a lifting detection sensor that detects contact with the sheet in which lifting has occurred and determines lifting.
[Additional note 6]
The lifting determination unit determines the lifting when the printing rate on one side is larger than a threshold value when double-sided printing is performed on the paper, and a jam occurs during printing on the other side. The conveyance device according to supplementary note 4.

1 Printing device 2 Paper feeding section 3 Belt platen conveyance section 4 Printing section 5 Circulation conveyance section 6 Paper discharge section 7 Operation panel 8 Control section 9 Housing 10 Ink pan 11 External paper feed table 12 External paper feed rollers 13A, 13B Internal feed Paper base 14A, 14B Internal paper feed roller 16A, 16B, 16C Internal paper feed transport roller 18 Vertical transport roller 20 Registration roller 22, 23, 24, 28, 48, 53, 54, 65, 66 Paper sensor 26, 26a Belt platen (Print transport section)
31 Head unit 32 Lifting drive section 36 Inkjet head 37 Head holder 41 Intermediate conveyance section 42 Reversing section 43 Lower conveyance section 44 Upward conveyance section 46 Intermediate conveyance roller 49 Reversing roller 51 Lower conveyance roller 56 Upward conveyance roller 63 Paper discharge roller 67 Paper discharge Stand 71 Display section 72 Input section 73 Space (predetermined space)
74 Guide member 81 Conveyor belt 82 Roller 83 Lifting detection sensor 83a Swing sensor section 83b Swing section

Claims (5)

a conveyance unit that has a print conveyance unit that conveys the paper below the inkjet head, and conveys the paper along a conveyance path passing through the print conveyance unit;
The printing conveyance unit is raised and lowered between a printing position, which is a position where the inkjet head is printing, and an intermediate position, which is a position below the printing position and where a predetermined space exists below the printing conveyance unit. a lifting drive unit for
an ink pan that receives ink that falls from the inkjet head during maintenance of the inkjet head;
a guide member provided in the ink pan and guiding the remaining paper sent to the predetermined space by the printing conveyance section;
a control unit that controls the transport unit to stop transporting the paper when a paper jam occurs in the transport path during printing by the inkjet head;
The control unit includes:
A conveyance device characterized in that, after lowering the print conveyance unit from the printing position to the intermediate position, the print conveyance unit is controlled so as to send out the remaining paper in the print conveyance unit to the predetermined space. a conveyance unit that has a print conveyance unit that conveys the paper below the inkjet head, and conveys the paper along a conveyance path passing through the print conveyance unit;
The printing conveyance unit is raised and lowered between a printing position, which is a position where the inkjet head is printing, and an intermediate position, which is a position below the printing position and where a predetermined space exists below the printing conveyance unit. a lifting drive unit for
a control unit that controls the transport unit to stop transporting the paper when a paper jam occurs in the transport path during printing by the inkjet head;
a lifting determination unit that determines lifting of the paper conveyed by the printing conveyance unit;
Equipped with
The control unit is configured to lower the print conveyance unit from the printing position to the intermediate position and then send out the remaining paper in the print conveyance unit to the predetermined space only when the lifting occurs. A conveyance device, characterized in that the print conveyance section is controlled. The conveyance device according to claim 2, further comprising a guide member that guides the remaining paper sent to the predetermined space by the printing conveyance section. The conveyance device according to claim 2, wherein the lifting determination unit is a lifting detection sensor that detects contact with the sheet in which lifting has occurred and determines lifting. The lifting determination unit determines the lifting when the printing rate on one side is larger than a threshold value when double-sided printing is performed on the paper, and a jam occurs during printing on the other side. The conveying device according to claim 2.

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