Image forming device

Abstract

To provide an image forming device in which a supply port of a housing is narrowed to a predetermined value or less during the operation of the image forming device and the supply port of the housing can be opened and closed during non-operation.SOLUTION: An image forming device 10 comprises: transportation means that transports a continuous recording medium 9; an image forming part that forms an image on a surface of the continuous recording medium 9; a housing 11 that houses the transportation means and the image forming part and has an opening 11o for supplying the continuous recording medium 9 from outside; and doors 12, 13 that are slidable in a direction orthogonal to a transportation width direction on a surface 11b on which the opening 11o of the housing 11 is formed. During operation, the doors 12, 13 block a part of the opening 11o, and a gap in the opening 11o serves as a supply port 1s through which the continuous recording medium 9 is inserted.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

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

[0002] An image forming apparatus comprises an image forming unit such as an inkjet head, a conveying means for conveying a sheet-like recording medium, which is the printing substrate, through the image forming unit, and a printer controller for controlling these. The conveying means is generally composed of two or more pairs of rollers that rotate while sandwiching the recording medium, or an endless belt (conveyor belt) stretched over two or more rotating rollers. An image forming apparatus that prints on a recording medium with particularly low rigidity, such as fabric, comprises, as a conveying means, a conveyor belt and rollers that rotate while sandwiching the recording medium on the upstream side of the image forming unit in the conveying direction (for example, Patent Documents 1 to 3).

[0003] In order to print on continuous recording media such as roll paper or fabric, an image forming apparatus is used with an external unwinder (paper feeder) on which a roll of unprinted continuous recording media is set. Therefore, while the image forming apparatus is operating (printing), a supply port is open in the housing (exterior) to allow the continuous recording media to pass through. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-63161 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-157450 [Patent Document 3] Patent Publication No. 2021-88129 Summary of the Invention [Problem to be solved by the invention]

[0005] In general, image forming apparatuses have a housing with a supply port located at waist to chest height due to the structure of the conveying mechanism, etc., and rollers that grip and rotate the recording medium are located near the supply port within the housing. Furthermore, image forming apparatuses are often installed with space near the supply port for workers to enter, for example, for continuous recording medium replacement. For such image forming apparatuses, the housing opening must be narrowed to a specified value or less (JIS B9718). However, it is desirable for image forming apparatuses to have a structure that allows the supply port to be opened widely for continuous recording medium replacement and other operations. Furthermore, image forming apparatuses that handle continuous recording media over 1 meter wide, such as fabrics, have large housings, and because continuous recording media replacement is frequent in small-lot production, it is desirable for the supply port to be able to be opened and closed with a simple structure.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an image forming apparatus that can narrow the supply port of the housing to a predetermined value or less when in operation, and can open and close the supply port of the housing when not in operation. [Means for solving the problem]

[0007] The above-mentioned problems of the present invention can be solved by the following configuration.

[0008] (1) a conveying means for conveying a continuous recording medium; an image forming unit that forms an image on the surface of the continuous recording medium; a housing that houses the conveying means and the image forming unit and has an opening for supplying a continuous recording medium from the outside; a door that is slidable in a direction perpendicular to the conveying width direction on a surface of the housing where the opening is formed, In operation, the image forming apparatus conveys the continuous recording medium to the conveying means by passing it through a gap formed when the door closes a portion of the opening.

[0009] (2) The image forming apparatus according to (1), wherein the door can be adjusted to a position where it does not come into contact with the continuous recording medium during operation.

[0010] (3) The image forming apparatus according to (2), wherein two doors are provided in a sliding movement direction, and the gap is formed between the doors.

[0011] (4) The conveying means has two or more conveying paths on the upstream side of the image forming unit in the conveying direction, The image forming apparatus according to (3), wherein the gap can be adjusted to a position corresponding to the selected transport path by sliding the door.

[0012] (5) The image forming apparatus according to (2), wherein the gap is adjustable in accordance with the thickness of the continuous recording medium.

[0013] (6) The image forming apparatus according to (2), wherein the gap is adjustable within a range wider than the thickness of the continuous recording medium and equal to or less than the thickness of the continuous recording medium plus 6 mm.

[0014] (7) An image forming apparatus as described in (2) that is provided with one or two guide rollers that can move in conjunction with the door near the opening and contact one side of the continuous recording medium being fed, each of which contacts one side.

[0015] (8) An image forming apparatus as described in (7) that is provided with two guide rollers, and one or two of the guide rollers are adjustable in position to correspond to the thickness of the continuous recording medium so that the guide rollers clamp the continuous recording medium between them.

[0016] (9) The image forming apparatus according to any one of (1) to (8), wherein the door is provided with an interlock switch so that the gap is kept at a predetermined value during operation.

[0017] (10) The image forming apparatus according to any one of (1) to (8), wherein the position of the door is continuously adjustable.

[0018] (11) a sensor for detecting the position of the continuous recording medium at the opening; The image forming apparatus according to (10), further comprising: a drive unit that moves the door in accordance with the position of the continuous recording medium in the opening.

[0019] (12) The image forming apparatus according to any one of (1) to (8), wherein the continuous recording medium is a fabric.

[0020] (13) The image forming apparatus according to (12), wherein the transport means includes a plurality of rollers and a transport belt stretched over the plurality of rollers, and the transport belt supports and transports the continuous recording medium.

[0021] (14) The image forming apparatus according to (13), wherein the conveying means includes a pressure roller, located upstream of the image forming unit in the conveying direction, for pressing the continuous recording medium against the conveying belt to support the continuous recording medium.

[0022] (15) The image forming apparatus according to (14), wherein the transport means includes an intermediate roller located upstream of the pressure roller in the transport direction, for tensioning the continuous recording medium between the pressure roller and the intermediate roller. [Effects of the Invention]

[0023] According to the image forming apparatus of the present invention, the supply opening of the housing can be narrowed to a predetermined value or less during operation, and the supply opening of the housing can be opened or closed during non-operation. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram illustrating the configuration of an image forming apparatus according to the present invention. [Figure 2] 1 is a block diagram illustrating a configuration of an image forming apparatus according to the present invention. [Figure 3] 1 is a cross-sectional perspective view of an image forming apparatus according to a first embodiment of the present invention. [Figure 4A] 2 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of the image forming apparatus according to the first embodiment of the present invention. FIG. [Figure 4B]2 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of the image forming apparatus according to the first embodiment of the present invention. FIG. [Figure 5] 1 is an external view of an image forming apparatus for explaining the configuration of a housing of the image forming apparatus according to a first embodiment of the present invention. [Figure 6] 1 is an external view of an image forming apparatus for explaining the configuration of a housing of the image forming apparatus according to a first embodiment of the present invention. [Figure 7] 2 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of the image forming apparatus according to the first embodiment of the present invention. FIG. [Figure 8A] 2 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of the image forming apparatus according to the first embodiment of the present invention. FIG. [Figure 8B] 2 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of the image forming apparatus according to the first embodiment of the present invention. FIG. [Figure 9] FIG. 10 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of an image forming apparatus according to a modified example of the first embodiment of the present invention. [Figure 10] FIG. 10 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of an image forming apparatus according to a modified example of the first embodiment of the present invention. [Figure 11A] FIG. 10 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of an image forming apparatus according to a modified example of the first embodiment of the present invention. [Figure 11B] FIG. 10 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of an image forming apparatus according to a modified example of the first embodiment of the present invention. [Figure 12A] FIG. 10 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of an image forming apparatus according to a modified example of the first embodiment of the present invention. [Figure 12B] FIG. 10 is a partial cross-sectional view illustrating the relationship between a transport path and the position of a door of a housing of an image forming apparatus according to a modified example of the first embodiment of the present invention. [Figure 13A] FIG. 10 is a partial cross-sectional view illustrating the relationship between the thickness of a continuous recording medium and the position of a door of a housing of an image forming apparatus according to a second embodiment of the present invention. [Figure 13B] FIG. 10 is a partial cross-sectional view illustrating the relationship between the thickness of a continuous recording medium and the position of a door of a housing of an image forming apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] An image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. Note that the size and positional relationship of components shown in the drawings may be exaggerated and the shape may be simplified for clarity. In the following description, identical or similar components are designated by the same reference numerals, and their description will be omitted where appropriate.

[0026] [First embodiment] FIG. 1 is a schematic diagram of an image forming apparatus according to the present invention, seen from the side. The image forming apparatus 10 shown in FIG. 1 is an inkjet-type image forming apparatus (inkjet textile printer) capable of printing on fabric. It has an external unwinder 81 and winder 82, and forms an image on the surface of a long, wide recording medium (continuous recording medium) 9, such as fabric. The image forming apparatus 10 is also a scanning-type image forming apparatus, and as described below, can form an image on the recording medium 9 that is long in the conveyance width direction. FIG. 2 is a block diagram illustrating the configuration of the image forming apparatus according to the present invention. FIG. 3 is a cross-sectional perspective view of the image forming apparatus according to the first embodiment of the present invention. As shown in FIGS. 1, 2, and 3, the image forming apparatus 10 includes a housing 1, a conveying device (conveying means) 3 that conveys the recording medium 9, an image forming unit 4 that forms an image on the recording medium 9, a conveying belt cleaning device 5, and sensors 6 (61, 62) (not shown in FIG. 3), all of which are housed in the housing 1, as well as a control unit 7 that controls the conveying device 3 and the image forming unit 4. The image forming device 10 may further include an imaging device that captures an image printed on a recording medium 9 inside the housing 1, an operation panel installed on the outer surface of the housing 1, a thermometer that measures room temperature and the temperature inside the housing 1, etc.

[0027] (Recording medium) The recording medium (continuous recording medium) 9, which is the printing substrate of the image forming apparatus 10, is a long sheet-like material. The image forming apparatus 10 can print on a recording medium 9, for example, with a width of 1800 mm or less and a thickness t of 3 mm or less. The recording medium 9 is supplied in lengths of several tens of meters or more, depending on the material and thickness. Examples of the recording medium 9 include fabric, paper, plastic film such as polypropylene (PP) or polyethylene terephthalate (PET), and tack paper with an adhesive applied to the backside and releasably attached to a release paper. The recording medium 9 is supplied to the image forming apparatus 10 in a form depending on the material and length. For example, the recording medium 9 is wound around a spool and fed from the outside of the wound state by the unwinder 81. As described above, the image forming apparatus 10 can print on fabric as the recording medium 9. Hereinafter, the components constituting the image forming apparatus 10 will be described, starting with the conveying device 3 and the image forming unit 4, which are the mechanical unit (printer engine) of the image forming apparatus 10.

[0028] (Transportation device) 1 and 3, and passes the recording medium 9 through an area (image forming area) facing the inkjet head 42 of the image forming unit 4. The conveying device 3 includes a conveying belt 31, a driving roller 32 that tensions the conveying belt 31, a driven roller 33, a belt guide roller 34, a pressure roller 35, an intermediate roller 36, guide rollers 37 and 38, and a motor (not shown) that rotates and drives the driving roller 32, etc.

[0029] The conveyor belt 31 is an endless belt that is stretched across a drive roller 32, a driven roller 33, and a belt guide roller 34, which rotate on a rotation axis in the width direction (Y direction), and is fed in a fixed direction (counterclockwise in the cross section of FIG. 3 ). The conveyor belt 31 has an adhesive outer surface (surface), and conveys the recording medium 9 with the recording medium 9 attached to the upper surface. The drive roller 32 is an active roller that receives rotation from a motor and is located near the downstream (front) end of the conveyor belt 31 to drive the conveyor belt 31. In this embodiment, the conveyor device 3 is driven by a motor that operates intermittently, repeatedly conveying and stopping at a predetermined cycle. The driven roller 33 is located near the upstream (rear) end of the conveyor belt 31 and, together with the drive roller 32, stretches the conveyor belt 31 forward and backward. The driven roller 33 is rotated by receiving the rotation of the drive roller 32 via the conveyor belt 31. In this specification, the terms upstream, downstream, front, and rear refer to the conveyor direction of the recording medium 9. In FIG. 3, the rotation directions of the drive roller 32, the driven roller 33, and the pressure roller 35 (described later) are indicated by thick arrows. Like the drive roller 32, the roller 33 may be an active roller to which rotation is transmitted directly from a motor. The belt guide roller 34 is a driven shaft with a smaller diameter than the drive roller 32 and the driven roller 33, rotatably supported, and rotates as the conveyor belt 31 moves. The belt guide roller 34 is provided as needed in a position in contact with the back surface of the conveyor belt 31. In this embodiment, the belt guide rollers 34 are disposed before and after the image forming area, and two more are disposed below, to prevent the conveyor belt 31 from sagging under its own weight, particularly on the upper side supporting the recording medium 9. This configuration allows the conveyor device 3 to pass the recording medium 9, such as fabric, through the image forming area in a flat state without sagging or wrinkles.

[0030] The pressure roller 35, intermediate roller 36, and guide rollers 37 and 38 are driven shafts that are rotatably supported on rotation axes in the conveyance width direction, similar to the belt guide roller 34, and rotate as the recording medium 9 is conveyed. The pressure roller 35 is provided upstream of the image forming area, sandwiching the recording medium 9 on the conveyor belt 31. In this embodiment, the pressure roller 35 is disposed in front of and near the driven roller 33. The pressure roller 35 adheres the recording medium 9 supplied into the housing 1 to the surface of the conveyor belt 31. The pressure roller 35 may be configured to be displaceable so that the distance from the conveyor belt 31 can be changed depending on the thickness of the recording medium 9. The intermediate roller 36 is disposed above and near the pressure roller 35, and stretches the recording medium 9 supplied into the housing 1 between itself and the pressure roller 35 in an S-shaped manner, eliminating slack and wrinkles.

[0031] The guide rollers 37, 38 are provided as needed, and the required number of guide rollers are installed at locations according to the transport path of the recording medium 9. In this embodiment, the guide rollers 38, 37 are arranged near the front and rear of the transport belt 31 so that their upper ends are approximately aligned with the transport belt 31, and of these, the front guide roller 38 is arranged outside the housing 1. In this embodiment, the guide roller 38 is arranged below the recording medium 9 (transport path) and contacts the back surface to support the recording medium 9 so that the transport device 3 does not come into contact with the front surface (printing surface) of the recording medium 9 in the image formation area and downstream thereof.

[0032] 1 and 3, as described above, the recording medium 9 is laminated to the conveyor belt 31 after passing through the intermediate roller 36 and the pressure roller 35 in this order, and the guide roller 37 near the rear of the conveyor belt 31 is not used. FIG. 4A shows a partial enlargement of FIG. 3. On the other hand, if the recording medium 9 is made of a thick or taut material, it is less likely to sag or wrinkle even if it is not wound around the pressure roller 35 and the intermediate roller 36, and it may be preferable to convey the recording medium 9 while avoiding a highly curved orientation. Therefore, as shown in FIG. 4B, the recording medium 9 moves onto the conveyor belt 31 in a substantially flat orientation, passing above the guide roller 37, and is pressed against the conveyor belt 31 by the pressure roller 35. Therefore, the conveyor device 3 has two conveyance paths upstream of the image forming area, which are selected depending on the type (thickness, material) of the recording medium 9. Furthermore, the height at which the recording medium 9 passes through the housing 1 when being supplied into the housing 1 differs for each conveyance path.

[0033] (Image forming section) The image forming unit 4 forms an image by depositing ink on the surface of the recording medium 9. The image forming unit 4 includes a carriage 41 carrying an inkjet head 42, guide rails 43 supporting the carriage 41, a motor for scanning the carriage 41 in the transport width direction of the recording medium 9, and a cleaning device (not shown) for cleaning the nozzle surfaces of the inkjet head 42. The carriage 41 carries inkjet heads 42 for each color aligned in the main scanning direction (transport width direction); FIG. 3 shows five inkjet heads 42. The inkjet heads 42 have nozzle holes on their nozzle surfaces facing the recording medium 9, and eject ink of, for example, Y (yellow), M (magenta), C (cyan), and K (black) from the nozzle holes. The carriage 41 further carries inkjet heads 42 that eject, for example, pretreatment agents depending on the printing method of the image forming apparatus 10. The guide rails 43 extend in the transport width direction and are provided so as to protrude outward on both sides of the transport device 3 (transport belt 31), supporting the carriage 41 so that it can move freely in the transport width direction. The cleaning device is disposed below the guide rails 43 and on the outer sides of the transport belt 31 in the transport width direction, and removes ink adhering to the nozzle surfaces of the inkjet heads 42. With this configuration, the image forming unit 4 can form an image across the entire width of the recording medium 9, which is longer in the transport width direction than the inkjet heads 42, by scanning the carriage 41 during periods when the transport device 3 is stopped during intermittent transport. Furthermore, the image forming unit 4 can clean the inkjet heads 42 by placing them opposite the cleaning device.

[0034] (Conveyor belt cleaning device) The conveyor belt cleaning device 5 is disposed below the conveyor belt 31 of the conveyor device 3, and removes ink and foreign matter adhering to the surface of the conveyor belt 31. The conveyor belt cleaning device 5 includes a roll brush that rubs against the surface of the conveyor belt 31, a cleaning tub that contains cleaning liquid so that the lower part of the roll brush is immersed, a motor that rotates the roll brush against the moving direction of the conveyor belt 31, and the like.

[0035] (sensor) The sensors 61 and 62 detect the position of the recording medium 9 near the supply port 1s of the housing 1. Specifically, the sensors 61 and 62 detect the position of the recording medium 9 in the height direction (Z direction) immediately after it enters the housing 1 from the outside to the inside. The sensors 61 and 62 can be any known device, such as a mechanical (contact) or optical device, capable of detecting the recording medium 9 stretched between the intermediate rollers 36 and the guide rollers 37 of the conveying device 3. As described above, the image forming apparatus 10 has two conveying paths for the recording medium 9 by the conveying device 3, and the sensors 61 and 62 are disposed at positions capable of detecting the recording medium 9 on each conveying path. For example, the sensor 61 is disposed near the upper and upstream side of the intermediate roller 36, at the center in the conveying width direction. For example, the sensor 62 is disposed near the upper or lower side of the guide roller 37, or near the upper side of the driven roller 33, at the center in the conveying width direction. When the sensors 61 and 62 are not distinguished from each other, they are referred to as sensor 6 (see FIG. 2). The sensor 6 may further be a media sensor that detects the physical properties (thickness, basis weight, surface texture, etc.) of the recording medium 9 in order to identify the type of the recording medium 9. The media sensor may be provided separately from the sensor 6, and if it is not built into the image forming apparatus 10, it may be installed as an external device between the image forming apparatus 10 and the unwinder 81.

[0036] (Housing) The housing 1 is an exterior member that houses the printer engine of the image forming apparatus 10, such as the conveying device 3 and the image forming unit 4, and is formed in any three-dimensional shape, such as a box with an open bottom. In the image forming apparatus 10, the housing 1 has a cross-shaped shape in plan (top) view, combining a rectangular parallelepiped that is long in the conveying direction (X direction) and that covers the conveying device 3 with a rectangular parallelepiped that is long in the conveying width direction (Y direction) and that covers the image forming unit 4. The portion that protrudes downstream (forward) is formed lower than the other portions to match the height of the conveying device 3. FIG. 5 shows a perspective view of the appearance of the housing 1 from the upstream side. The housing 1 also has a supply port 1s and a discharge port 1d, which are elongated openings in the conveying width direction and allow the recording medium 9 to pass through, formed on vertical surfaces at both ends in the conveying direction. The length of the supply port 1s and the discharge port 1d in the conveying width direction is greater than the maximum width of the recording medium 9 to prevent contact between the recording medium 9, and the gap (short side length, opening length) is set to be equal to or smaller than the maximum thickness t of the recording medium 9 in the image forming apparatus 10. MAX The gap is larger than (t MAX +2mm) or more is preferable, and (t MAX +3 mm) or more is more preferable. For the supply port 1s, the gap e is preferably 6 mm or less (JIS B9718). The housing 1 is arranged near the supply port 1s and is formed so that its inner surface is spaced 10 mm or more from components that operate during operation, specifically, the conveyor belt 31, pressure roller 35, intermediate roller 36, and guide roller 37 of the conveyor device 3 (JIS B9718). The housing 1 comprises a main body 11 and doors 12 and 13, each of which is formed from a metal plate or the like. The vertical surfaces (plates) at both ends of the main body 11 in the conveying direction are referred to as the front surface 11f (downstream side) and the rear surface 11b (upstream side). The doors 12 and 13 are attached to the outside of the rear surface 11b of the main body 11.

[0037] The main body 11 has a discharge port 1d formed on its front surface 11f. The main body 11 also has an opening 11o formed on its rear surface 11b for forming a supply port 1s and for operations such as replacing the recording medium 9. In the image forming apparatus 10, as shown in FIGS. 4A and 4B, the conveying device 3 conveys the recording medium 9 in two different ways. Therefore, the opening 11o is positioned and sized to encompass both conveying paths on the front surface 11f. Furthermore, the opening 11o is sized and positioned to allow a worker to view the interior of the housing 1 from the outside as far as necessary and to allow the worker's upper limbs to reach as far as necessary, so that the worker can perform the work. Therefore, the length of the opening 11o in the conveying width direction (long side length) is greater than the maximum width of the recording medium 9, and the length in the direction perpendicular to the conveying width direction, i.e., the height, is, for example, 0.1 m to 1 m. In this embodiment, the opening 11o is formed across the entire conveying width direction of the rear surface 11b and extends to both side surfaces of the main body 11 that are continuous with the rear surface 11b.

[0038] The doors 12 and 13 are provided to close the opening 11o of the main body 11, leaving the supply port 1s open. To this end, the doors 12 and 13 are formed as plates bent into a U-shape in top view so as to cover the rear surface 11b of the main body 11 and the outer sides of the side surfaces connected thereto. The doors 12 and 13 are sliding doors (separate sliding doors) that slide vertically, and, for example, both edges are fitted into guide rails (not shown) provided on the main body 11. The upper door 12 can be slid upward, and the lower door 13 can be slid downward, respectively, to fully open the opening 11o of the main body 11, as shown in FIG. 5 . Meanwhile, a notch in the shape of the supply port 1s is formed in the lower edge of the door 12 so that the supply port 1s is formed when the doors 12 and 13 are butted together (closed). The notch may be formed near the upper edge of the door 13, or may be formed on both the doors 12 and 13.

[0039] Alternatively, the housing 1 may be configured to include doors 12A and 13A without notches, as shown in Fig. 6. In such a housing 1, the main body 11A has an opening 11o formed only on the rear surface 11b. During operation, the doors 12A and 13A are not completely closed, but are closed with a gap e. The length of the supply port 1s in the conveying width direction is the same as the length of the opening 11o of the main body 11A in the conveying width direction.

[0040] The doors 12 and 13 each have a handle or pull tab attached to their outer surface (not shown) and are configured to be opened and closed manually. In this embodiment, handles are attached not only to the rear surfaces of the doors 12 and 13 but also to their side surfaces, allowing an operator to open and close the doors 12 and 13 while standing beside the image forming apparatus 10. The doors 12 and 13 may be attached to the inside of the rear surface 11b of the main body 11. In this case, when the doors are fully open, the handles attached to the lower end of the door 12 and the upper end of the door 13 are exposed through the opening 11o of the main body. The housing 1 may incorporate a motor (not shown) to electrically slide the doors 12 and 13, or the doors 12 and 13 may be opened and closed by operating a switch installed on the outer surface of the housing 1 (main body 11 or doors 12 and 13). Alternatively, the doors 12 and 13 may be controlled by the control unit 7, and are opened and closed by inputting an open / close command to an operation panel. The drive source for the doors 12 and 13 is not limited to a motor, but an air cylinder, a hydraulic cylinder, or the like can also be used.

[0041] Furthermore, in the image forming apparatus 10, the position of the supply opening 1s can be changed vertically by changing the positions of the doors 12 and 13 and closing them. As shown in FIG. 4A , when the recording medium 9 is supplied onto the conveyor belt 31 while being stretched between the intermediate roller 36 and the pressure roller 35, the doors 12 and 13 are closed at the top of the opening 1o so that the supply opening 1s is aligned with the upper end of the intermediate roller 36. As shown in FIG. 4B , when the recording medium 9 is supplied onto the conveyor belt 31 in a substantially flat state from the guide roller 37, the doors 12 and 13 are closed at the bottom of the opening 1o so that the supply opening 1s is aligned with the upper end of the guide roller 37. To this end, the doors 12 and 13 are formed with dimensions that allow the supply opening 1s to be opened and the opening 1o to be blocked when the doors 12 and 13 are closed at the top and bottom of the opening 1o, respectively. Furthermore, the doors 12 and 13 may each be provided with a stopper so that they can be locked at each position shown in FIGS. 4A , 4B , and 5 , and may be configured to be movable in stages. Also, the doors 12 and 13 may be configured so that they cannot be moved together when closed.

[0042] The housing 1 may be equipped with an interlock switch 21. The interlock switch 21 sets the image forming apparatus 10 so that it can operate (print) when the doors 12 and 13 are completely closed. Therefore, the image forming apparatus 10 may be configured so that if the doors 12 and 13 are not closed, the image forming apparatus 10 will not start operation even if the operation panel or the like is operated, and may also be configured to notify the user that the doors 12 and 13 are not closed. Furthermore, the doors 12 and 13 cannot be moved (opened) during operation. With this configuration, the image forming apparatus 10 can more reliably narrow the opening (supply port 1s) of the housing 1 to a predetermined value or less during operation.

[0043] (Control unit) The control unit 7 is a printer controller for the image forming apparatus 10, and as shown in Fig. 2, drives and controls the printer engine, which is an element of the image forming apparatus 10 other than the control unit 1. The control unit 7 may further be configured to act as a drive unit for the doors 12 and 13 of the housing 1, so as to close the doors 12 and 13 at appropriate positions when a closing operation is input in accordance with the position of the recording medium 9 detected by the sensors 6 (61 and 62). In order to be equipped with these elements, the control unit 7 has a CPU (Central Processing Unit), memory for storing software and temporarily storing input job data, and the like.

[0044] (Unwinding machine) The unwinder 81 is a device (unwinder, feeder) that supplies the recording medium 9 wound around a spool in a roll to the image forming apparatus 10 and is installed on the supply port 1s side of the image forming apparatus 10. The unwinder 81 includes a feed roller 83, a guide roller 84, a movable guide roller 85, a housing 86, and a motor (not shown) that rotates the feed roller 83. The unwinder 81 may further include a cutter that cuts the recording medium 9, as necessary. The feed roller 83 is a driven shaft that receives rotational motion from the motor and rotates on a rotation axis in the conveyance width direction, and is also a support member that fits and engages with the spool. The feed roller 83 supports the recording medium 9 wound around the spool and rotates the spool at an appropriate rotational speed to feed the recording medium 9 from the outside of the wound state. The guide rollers 84 are driven shafts that are rotatably supported and rotate as the recording medium 9 moves. A required number of guide rollers are installed at locations corresponding to the conveyance path of the recording medium 9. In FIG. 1 , two upstream guide rollers 84 are located inside the housing 86, and three downstream guide rollers 84 are located outside the housing 86. The movable guide roller 85, like the guide roller 84, is a driven shaft, but is attached to the end of a tension arm that is freely rotatable within a predetermined angle and displaces within a predetermined range. In FIG. 1 , the tension arm is L-shaped, rotates around an axis, and a movable guide roller 85 is attached to each end. The movable guide roller 85 is located inside the housing 86 to slacken the recording medium 9 between the two guide rollers 84, 84, thereby suppressing slack in the recording medium 9 between the image forming device 10 and the unwinder 81. With this configuration, even if the feed roller 83 is continuously operating, the unwinder 81 can suppress slack in the recording medium 9 between the image forming device 10, which is intermittently transported by the transport device 3. Furthermore, because the recording medium 9 is wound with its front surface (printed surface) facing inward, the unwinder 81 feeds the recording medium 9 with this surface facing up. The feed roller 83 may be a driven shaft, and rotates together with the spool when the recording medium 9 is fed from the wound outside by the conveying device 3. It is preferable that such a feed roller 83 has a structure that applies an appropriate load to the rotation, such as a torque limiter, so as to prevent excessive rotation and slack in the recording medium 9.

[0045] (winding machine) The winder 82 is a device (winder) that winds and stores the recording medium 9 on which an image is formed by the image forming apparatus 10, and is installed on the discharge port 1d side of the image forming apparatus 10. Furthermore, in this embodiment, the winder 82 also functions as a dryer for post-printing treatment. To this end, the winder 82 includes a heater 87, a winding roller 88, a guide roller 84, a movable guide roller 85, a housing 89, and a motor (not shown) that rotates and drives the winding roller 88. The winder 82 may further include a cutter that cuts the recording medium 9, as necessary. The heaters 87 are arranged in the housing 89 across the entire width of the recording medium 9, and four heaters 87 are arranged side by side in the conveyance direction in FIG. 1 to dry the recording medium 9. The winding roller 88 has a structure similar to that of the delivery roller 83 of the unwinder 81. It rotates the fitted spool at an appropriate rotational speed to wind the recording medium 9 onto the spool with its surface (printed surface) facing inward. The guide rollers 84 and the movable guide rollers 85 can have the same structures as the guide rollers 84 and the movable guide rollers 85 of the unwinder 81. In Fig. 1, four guide rollers 84 are arranged inside a housing 89, and the first and second guide rollers 84, 84 from the upstream side are arranged with a heater 87 between them, with the recording medium 9 stretched and facing the heater 87. In the winder 82, the guide roller 84 is arranged below the recording medium 9 (transport path) on the upstream side of the heater 87 so as not to come into contact with the front surface (printed surface) of the recording medium 9 before drying, and comes into contact with the back surface to support the recording medium 9.

[0046] (Operation of image forming device) 3, 4A and 4B, the opening and closing of the housing of the image forming apparatus and the operation of the conveying device according to the present invention will be described. First, the operation when printing on a recording medium 9 that is prone to wrinkling will be described.

[0047] As shown in FIG. 4A, when the recording medium 9 is wound in an S-shape from the intermediate roller 36 to the pressure roller 35 and then introduced between the intermediate roller 36 and the pressure roller 35, the height position of the conveying path is the upper end of the intermediate roller 36. Therefore, after the recording medium 9 is set in the fully open state (see FIG. 5), the door 12 is moved downward and the door 13 is moved upward so that the supply port 1s is at this position. In the case of manual operation, the door 12 stops moving at the first stopper, and the door 13 stops moving at the second stopper. Once the doors 12 and 13 are closed, operation begins.

[0048] Next, we will explain the operation when switching to a recording medium 9 that is relatively thick and wrinkle-resistant. After stopping the image forming apparatus 10, doors 12 and 13 are fully opened, and the recording medium 9 is replaced. As shown in FIG. 4B, the recording medium 9 is inserted between the pressure roller 35 and the conveyor belt 31 from above the guide roller 37. At this time, the height position of the conveyance path is the upper end of the guide roller 37. Therefore, after setting the recording medium 9, door 12 is moved downward and door 13 is moved upward so that the supply port 1s is located at this position. In the case of manual operation, door 12 stops moving at the second stopper and door 13 stops moving at the first stopper. Note that it is preferable to switch the conveyance path in the unwinder 81 so that the takeout position of the recording medium 9 from the unwinder 81 is aligned with the upper end of the guide roller 37. In FIGS. 4A and 4B, the conveyance path of the guide roller 84 outside the housing 86 in the unwinder 81 is switched depending on the type of recording medium 9.

[0049] If the doors 12 and 13 are electrically operated, they can be opened and closed using a switch or an operation panel. Furthermore, sensors 61 and 62 may detect the position of the recording medium 9 near the opening 1o, and the doors 12 and 13 may be moved so that the position of the supply port 1s is aligned with the recording medium 9.

[0050] The doors 12 and 13 may be configured so that they can be closed by changing their positions in a stepless manner. For example, if the unwinder 81 is configured so that the take-out position of the recording medium 9 cannot be changed arbitrarily, the recording medium 9 will be tilted between the unwinder 81 and the image forming device 10 (between the pressure roller 35 and the conveyor belt 31), as shown in FIG. 7. The doors 12 and 13 can be moved to accommodate the recording medium 9 in this position. Furthermore, as described above, the doors 12 and 13 are electrically operated, and by detecting the position of the recording medium 9 with sensors 61 and 62, the doors 12 and 13 can be moved and closed so that the supply port 1s is in an appropriate position.

[0051] Furthermore, if the take-out position of the unwinder 81 for the recording medium 9 changes during operation, this can be accommodated. Specifically, as shown in FIGS. 8A and 8B, the unwinder 81 has a simple configuration including only a driven shaft feed roller 83A, and the recording medium 9 attached to the feed roller 83A is directly supplied to the image forming apparatus 10. As operation progresses, the remaining amount of recording medium 9 attached to the feed roller 83A decreases, and the diameter becomes smaller, so the take-out position of the recording medium 9 shifts. Therefore, during operation, the image forming apparatus 10 detects the position of the recording medium 9 using sensor 61 or sensor 62, and moves the doors 12 and 13, while closed, in the direction indicated by the arrow with a dotted pattern in FIGS. 8A and 8B to follow the recording medium 9. This prevents the doors 12 and 13 from coming into contact with the recording medium 9, and maintains the gap e of the supply port 1s.

[0052] (Variation) To avoid contact with the housing 1 (doors 12 and 13) when passing through the supply port 1s, the recording medium 9 is preferably positioned as close to perpendicular to the rear surface 11b of the main body 11 and the doors 12 and 13 as possible, and most preferably perpendicular. Specifically, depending on the difference between the gap e of the supply port 1s and the thickness of the recording medium 9, the difference is preferably within ±15°. As shown in FIGS. 4A and 4B, if the unwinder 81 is configured to change the take-out position of the recording medium 9, it is preferable to adjust the take-out position before operation to match the transport path of the image forming apparatus 10 so that the recording medium 9 is horizontal relative to the image forming apparatus 10. However, if the take-out position cannot be changed (see FIG. 7) or changes during operation (see FIGS. 8A and 8B), the recording medium 9 may enter the supply port 1s at a large angle, potentially causing contact with the housing 1. To avoid contact between the housing 1 and the recording medium 9, the image forming apparatus 10 can be configured as follows.

[0053] As shown in FIG. 9, an image forming apparatus 10A according to a modification of the first embodiment of the present invention includes a guide roller 23 attached to the outer surface of the door 13 of the housing 1, in contrast to the image forming apparatus 10 according to the previous embodiment. The guide roller 23 can have a structure similar to that of the guide rollers 37 and 38 of the conveying device 3. The guide roller 23 is positioned so that its upper end is higher than the upper end of the door 13 (the upper end of the supply port 1s). Compared to FIG. 4A, which shows the image forming apparatus 10 according to the previous embodiment, FIG. 9 illustrates a mode in which the recording medium 9 is supplied from an unwinder 81 including only a feed roller 83A (see FIG. 8A). According to the previous embodiment, the recording medium 9 enters the supply port 1s at a large incline, which may cause it to come into contact with the doors 12 and 13. In contrast, according to this modification, the recording medium 9 enters the supply port 1s substantially horizontally, making it less likely to come into contact with the housing 1. Depending on the position from which the unwinder 81 takes out the recording medium 9, a guide roller 22 (see FIG. 10) may be attached to the outer surface of the door 12. The guide roller 22 is disposed so that its lower end is lower than the lower end of the door 12 (the lower end of the supply port 1s).

[0054] 10, guide rollers 22 and 23 may be attached to both doors 12 and 13. The gap between the guide rollers 22 and 23 is set to be narrower than the gap e between the supply ports 1s and to be equal to or smaller than the maximum thickness t MAX The above is all. Alternatively, the guide rollers 22 (or guide rollers 23) may be configured to be movable, with the gap adjusted to the thickness t of the recording medium 9 so that the guide rollers 22, 23 hold the recording medium 9 between them. According to this modification, the recording medium 9 is less likely to come into contact with the housing 1 as described above, and the doors 12, 13 (supply opening 1s) can be fixed at predetermined positions corresponding to the transport path of the recording medium 9 by the transport device 3 for operation, regardless of the unwinder 81's removal position for the recording medium 9.

[0055] As shown in Figures 11A and 11B, guide rollers 22 and 23 may be attached to the inner surfaces of doors 12 and 13. In image forming apparatus 10B according to another modification of the first embodiment of the present invention, doors 12 and 13 (supply port 1s) are aligned with the unwinder 81's removal position for recording medium 9 so that recording medium 9 enters supply port 1s substantially horizontally. Furthermore, during operation, doors 12 and 13 are moved in the directions indicated by the arrows with dotted patterns in Figures 11A and 11B, following the recording medium 9. According to this modification, guide rollers 22 and 23, which rotate during operation, are disposed inside housing 1, and therefore can comply with JIS B9718.

[0056] The housing 1 may have openings on the rear surface of the main body 11 for each transport path of the recording medium 9 by the transport device 3. As shown in FIGS. 12A and 12B, an image forming apparatus 10C according to another modification of the first embodiment of the present invention has openings 11o1 and 11o2 formed on the rear surface of the main body 11B of the housing 1, with the upper opening 11o1 being closed by a door 12B and the lower opening 11o2 being closed by a door 13B. Specifically, in a transport path in which the recording medium 9 passes above the intermediate roller 36, as in FIG. 4A, the door 12B opens the supply port 1s to close the opening 11o1, and the door 13B completely closes the opening 11o2, as shown in FIG. 12A. Meanwhile, in a transport path in which the recording medium 9 enters between the pressure roller 35 and the transport belt 31 from above the guide roller 37, as in FIG. 4B, the door 12B completely closes the opening 11o1, and the door 13B opens the supply port 1s to close the opening 11o2, as shown in FIG. 12B. Therefore, in image forming apparatus 10C, supply port 1s is provided in the gap between door 12B and main body 11B (FIG. 12A) or in the gap between door 13B and main body 11B (FIG. 12B).

[0057] The rear surface of the main body 11 of the housing 1 is not limited to a vertical surface but may be inclined, and further is not limited to a flat surface but may be a cylindrical surface that forms an arc when viewed from the side (XZ plane). The doors 12 and 13 are formed in a shape that matches the shape of such a rear surface of the main body 11. In this case, too, when the recording medium 9 passes through the supply port 1s, it is preferable that its posture is as close to perpendicular to the doors 12 and 13 (the imaginary plane in the gap), and it is most preferable that it is perpendicular.

[0058] Second Embodiment When printing on thick fabrics, such as those exceeding 3 to 4 mm in thickness, it is preferable for the image forming apparatus to have a wide supply port gap exceeding 6 mm. However, if the supply port gap is wide, when printing on thin recording media, such as those 1 mm or less in thickness, an opening wider than 6 mm will be formed at the supply port, which does not comply with JIS B 9718. Therefore, the following configuration can be used to change the supply port gap, keeping the supply port opening at 6 mm or less during operation while preventing the recording medium from coming into contact with the supply port.

[0059] 13A and 13B correspond to partial enlarged views of FIG. 3. In an image forming apparatus 10D according to a second embodiment of the present invention, the housing 1 includes a main body 11A and doors 12A and 13A as shown in FIG. 6, as compared to the image forming apparatus 10 according to the first embodiment. The doors 12A and 13A are closed with a gap, and the gap can be changed. The image forming apparatus 10D shown in FIGS. 13A and 13B uses a conveyance path in which the recording medium 9 enters between the pressure roller 35 and the conveyor belt 31 from above the guide roller 37, similar to the image forming apparatus 10 shown in FIG. 4B. Note that the conveyance path in which the recording medium 9 passes above the intermediate roller 36 is the same as that shown in FIG. 4A. When the thickness t of the recording medium 9 is equal to or smaller than a predetermined value (e.g., 3 mm), the gap e of the supply port 1s is set to a minimum value e as shown in FIG. 13A. MIN The doors 12A and 13A are closed with a gap therebetween (for example, 6 mm).

[0060] On the other hand, when the recording medium 9 is replaced with one having a thickness exceeding a predetermined value, as shown in FIG. 13B, the doors 12A and 13A are closed so that the gap e corresponds to the thickness t. Specifically, the gap e of the supply port 1s is larger than the thickness t of the recording medium 9, and is preferably (t+2 mm) or more, and more preferably (t+3 mm) or more. On the other hand, the gap e of the supply port 1s is preferably (t+6 mm) or less (JIS B9718). With this configuration, the gap at the supply port 1s during operation is kept to 6 mm or less, regardless of the thickness of the recording medium 9. The gap e of the supply port 1s may be continuously adjusted to, for example, (t+6 mm), or may be adjusted to, for example, 6 mm (=e MIN ), 8 mm, 10 mm, ... for each thickness t in a predetermined range. The thickness t of the recording medium 9 may be detected by sensors (media sensors) 61 and 62, or may be input by an operator to the control unit 7. Furthermore, the image forming apparatus 10D may be provided with an interlock switch 21 (see FIG. 6) so that it will not operate unless the doors 12A and 13A are closed to a gap e corresponding to the thickness t of the recording medium 9.

[0061] In image forming apparatus 10D according to this embodiment, while maintaining the gap between doors 12A and 13A at gap e of supply port 1s, the position of the gap may be changed and closed in accordance with the removal position of recording medium 9 of unwinder 81, as in the first embodiment (see FIG. 7), or the position of the gap may be moved during operation (FIGS. 8A and 8B). Furthermore, as in the modified example of the first embodiment, guide rollers 22 and 23 may be attached to the outer or inner surfaces of doors 12A and 13A (FIGS. 9, 10, 11A, and 11B). Furthermore, as in the modified example of the first embodiment, openings may be formed in the rear surface of main body 11A for the respective transport paths of recording medium 9 by transport device 3, and each opening may be closed by a door (FIGS. 12A and 12B).

[0062] The present invention is not limited to the above-described embodiment, and modifications can be made without departing from the spirit of the present invention.

[0063] For example, in the above embodiment, the conveying device has two conveying paths, but it may have three or more paths, as long as the housing is configured to allow the supply port to be moved to a position corresponding to each conveying path. Alternatively, the conveying device may have one conveying path, in which case the housing may have one door. Also, in the above embodiment, the conveying path in the image forming area is horizontal, and the image forming unit is disposed above it, but the location of the image forming unit, the orientation of the conveying path, and the associated configuration of the conveying device are not limited.

[0064] The conveying device may be configured according to the type and size of the recording medium, and may be configured to convey the recording medium by tensioning multiple pairs of rollers that sandwich the recording medium instead of using a conveying belt. The image forming apparatus may be a single-pass type, i.e., the image forming unit does not have a guide rail or a scanning carriage, but the conveying device conveys the recording medium continuously. The image forming apparatus is not limited to an inkjet type, and may be an electrophotographic type such as a laser printer. [Explanation of symbols]

[0065] 10,10A,10B,10C,10D Image forming device 1 chassis 1s supply port 11, 11A, 11B Main body (housing) 11o,11o1,11o2 opening 12, 12A, 12B Doors 13, 13A, 13B Doors 21 Interlock switch 22,23 Guide roller 3. Transport means (transport device) 31 Conveyor belt 32 Drive roller 33 Driven roller 34 Belt guide roller 35 Pressure roller 36 Intermediate roller 37,38 Guide roller 4 Image forming unit 41 Carriage 42 Inkjet head 43 Guide rail 5. Conveyor belt cleaning device 61,62 Sensor 7 Control Unit 81 Unwinding machine 82 Winder 9 Recording media (continuous recording media)

Claims

1. a conveying means for conveying the continuous recording medium; an image forming unit that forms an image on the surface of the continuous recording medium; a housing that houses the conveying means and the image forming unit and has an opening for supplying a continuous recording medium from the outside; a door that is slidable in a direction perpendicular to the conveyance width direction on a surface of the housing where the opening is formed, In operation, the image forming apparatus conveys the continuous recording medium to the conveying means by passing it through a gap formed when the door closes a portion of the opening.

2. 2. The image forming apparatus according to claim 1, wherein the door can be adjusted to a position where it does not come into contact with the continuous recording medium during operation.

3. 3. The image forming apparatus according to claim 2, wherein two doors are provided in a sliding movement direction, and the gap is formed between the doors.

4. the conveying means has two or more conveying paths on the upstream side of the image forming unit in the conveying direction, 4. The image forming apparatus according to claim 3, wherein the gap can be adjusted to a position corresponding to the selected transport path by sliding the door.

5. 3. The image forming apparatus according to claim 2, wherein the gap is adjustable in accordance with the thickness of the continuous recording medium.

6. 3. The image forming apparatus according to claim 2, wherein the gap is adjustable within a range wider than the thickness of the continuous recording medium and equal to or less than the sum of the thickness of the continuous recording medium and 6 mm.

7. 3. The image forming apparatus according to claim 2, further comprising one or two guide rollers that are movable in conjunction with the door near the opening and contact one side of the continuous recording medium to be fed.

8. 8. An image forming apparatus as described in claim 7, wherein the image forming apparatus is provided with two guide rollers, and one or two of the guide rollers are adjustable in position to correspond to the thickness of the continuous recording medium so that the guide rollers sandwich the continuous recording medium between them.

9. 9. The image forming apparatus according to claim 1, wherein the door is provided with an interlock switch so that the gap is kept at a predetermined value during operation.

10. 9. The image forming apparatus according to claim 1, wherein the position of the door is continuously adjustable.

11. a sensor for detecting the position of the continuous recording medium at the opening; The image forming apparatus according to claim 10 , further comprising: a drive unit that moves the door in accordance with a position of the continuous recording medium in the opening.

12. 9. The image forming apparatus according to claim 1, wherein the continuous recording medium is a fabric.

13. 13. The image forming apparatus according to claim 12, wherein the transport means comprises a plurality of rollers and a transport belt stretched over the plurality of rollers, and the transport belt supports and transports the continuous recording medium.

14. 14. The image forming apparatus according to claim 13, wherein the transport means includes a pressure roller, located upstream of the image forming unit in the transport direction, for pressing the continuous recording medium against the transport belt to support the continuous recording medium.

15. 15. The image forming apparatus according to claim 14, wherein the transport means includes an intermediate roller, which is located upstream of the pressure roller in the transport direction and stretches the continuous recording medium between the pressure roller and the intermediate roller.

Images