Ink jet recording device

Abstract

To provide an ink jet recording device which can be miniaturized.SOLUTION: An ink jet recording device includes: a conveyance section; a recording head; a head housing; and a guide rail. The recording head has an ink discharge surface provided with a plurality of nozzles for discharging ink to a recording medium conveyed by the conveyance section. The head housing holds the recording head. The guide rail reciprocally supports the head housing with respect to conveyance belt. The ink discharge surface is in parallel to a conveyance surface of the conveyance belt. The ink discharge surface is inclined to a horizontal direction in a cross section orthogonal to an axial direction of a conveyance roller. By moving the head housing along the guide rail extending in the horizontal direction, the ink discharge surface reciprocates to a printing position coming close to the conveyance surface and a maintenance position retreated from the conveyance surface.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] A conventional inkjet recording device includes a transport unit, a recording head, a head housing, and a guide rail. The transport unit has a transport belt that transports the recording medium. The recording head has an ink ejection surface provided with a plurality of nozzles that eject ink onto the recording medium transported by the transport unit. The head housing holds the recording head. The guide rail supports the head housing so that it can be retracted relative to the transport belt. The ink ejection surface is parallel to the transport surface of the transport belt. By moving the head housing along the guide rail that extends in the vertical direction, the ink ejection surface reciprocates between a printing position close to the transport surface and a maintenance position retracted from the transport surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-262808 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the inkjet recording apparatus disclosed in the above-mentioned Patent Document 1 has a problem in that the head housing moves in the vertical direction, so that the apparatus becomes large in size in the vertical direction.

[0005] An object of the present invention is to provide an inkjet recording apparatus that can be made compact. [Means for solving the problem]

[0006] In order to achieve the above object, a first configuration of the present invention is an inkjet recording device including a transport section, a recording head, a head housing, and a guide rail. The transport section includes a transport belt for transporting a recording medium, and a transport roller around which the transport belt is stretched. The recording head has an ink ejection surface provided with a plurality of nozzles for ejecting ink onto the recording medium transported by the transport section. The head housing holds the recording head. The guide rail supports the head housing so that it can move back and forth relative to the transport belt. The ink ejection surface is parallel to the transport surface of the transport belt. Also, the ink ejection surface is inclined with respect to the horizontal direction in a cross section perpendicular to the axial direction of the transport roller. By moving the head housing along the guide rail extending in the horizontal direction, the ink ejection surface moves back and forth between a printing position close to the transport surface and a maintenance position retracted from the transport surface. Effect of the Invention

[0007] According to the first aspect of the present invention, it is possible to provide an inkjet recording apparatus that can be made compact. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the overall configuration of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention. [Diagram 2] A plan view of the first conveying unit 5 and the recording unit 9 of the printer 100. [Diagram 3] A side view of the recording heads 17a to 17c constituting the line heads 11C to 11K of the recording unit 9 of the printer 100. [Figure 4] A plan view of the recording heads 17a to 17c of the printer 100 as viewed from the ink ejection surface F side. [Diagram 5] FIG. 1 is a perspective view showing a part of a first conveying unit 5 and a recording unit 9 of a printer 100. [Figure 6] FIG. 1 is an explanatory diagram showing the operation of the recording unit 9 relative to the first conveying unit 5 of the printer 100. [Figure 7]FIG. 1 is an explanatory diagram showing the operation of the recording unit 9 relative to the first conveying unit 5 of the printer 100. [Figure 8] FIG. 1 is an explanatory diagram illustrating a recovery operation of the recording heads 17a to 17c of the printer 100. [Figure 9] FIG. 1 is an explanatory diagram illustrating a recovery operation of the recording heads 17a to 17c of the printer 100. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Configuration of the Inkjet Recording Apparatus A printer 100 (inkjet recording device, hereinafter referred to as the printer 100) according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a printer 100 according to an embodiment of the present invention. For ease of explanation, the vertical direction in an installed state (as shown in FIG. 1) in which the printer 100 can be used is defined as the up-down direction (Z1-Z2 direction). In addition, the front side of the printer 100 shown in FIG. 1 is defined as the front (front face) and the front-rear direction (Y1-Y2 direction) is defined. In addition, the left-right direction (X1-X2 direction) is defined based on the front face of the printer 100 in the installed state. In this embodiment, the left-right direction (X1-X2 direction) is perpendicular to the up-down direction (Z1-Z2 direction) and the front-rear direction (Y1-Y2 direction).

[0010] The printer 100 is equipped with a paper feed cassette 2 which is a paper storage section. The paper feed cassette 2 is located at the bottom inside the printer main body 1. Paper P, which is an example of a recording medium, is stored inside the paper feed cassette 2. A paper feed device 3 is located downstream of the paper feed cassette 2 in the paper transport direction, that is, above the right side (X1 side) of the paper feed cassette 2 in FIG. 1. The paper feed device 3 separates and sends out the paper P one sheet at a time toward the upper right of the paper feed cassette 2 in FIG. 1.

[0011] The printer 100 also has a first paper transport path 4a inside. The first paper transport path 4a is located in the upper right corner, which is the paper feed direction of the paper feed cassette 2. The paper P sent out from the paper feed cassette 2 is transported vertically upward along the side of the printer body 1 by the first paper transport path 4a.

[0012] A registration roller pair 13 is provided at the downstream end of the first paper transport path 4a in the paper transport direction. Furthermore, a first belt transport section (transport section) 5 and a recording section 9 are arranged immediately downstream in the paper transport direction of the registration roller pair 13. The paper P sent out from the paper feed cassette 2 passes through the first paper transport path 4a and reaches the registration roller pair 13. The registration roller pair 13 temporarily stops the paper P to correct the skewed feed, timing it with the ink ejection operation performed by the recording section 9, and transports the paper P again toward the first belt transport section (transport section) 5.

[0013] A second belt conveying section 12 is disposed downstream (left side X2 in FIG. 1) of the first belt conveying section (conveying section) 5 in the paper conveying direction. The paper P on which an ink image has been recorded in the recording section 9 is sent to the second belt conveying section 12, and the ink ejected onto the surface of the paper P is dried while passing through the second belt conveying section 12.

[0014] A decurler unit 14 is provided downstream of the second belt transport unit 12 in the paper transport direction and near the left side of the printer body 1. The paper P from which the ink has been dried by the second belt transport unit 12 is sent to the decurler unit 14, where any curls in the paper P are straightened out using multiple rollers aligned in the paper width direction.

[0015] A second paper transport path 4b is provided downstream of the decurler unit 14 in the paper transport direction (upper in FIG. 1). When double-sided recording is not performed on the paper P that has passed through the decurler unit 14, the paper P is discharged from the second paper transport path 4b via a pair of discharge rollers to a paper discharge tray 15 provided outside the left side of the printer 100.

[0016] In addition, a maintenance unit 19 and a cap unit 30 are disposed below the second belt transport section 12. The maintenance unit 19 moves below the recording section 9 when performing a purge, which will be described later, and wipes off ink pushed out from ejection nozzles (nozzles) 18 (see FIG. 2) of the recording heads 17a to 17c, which will be described later, and collects the wiped ink. The cap unit 30 moves below the recording section 9 when capping the ink ejection surfaces F (see FIG. 3) of the recording heads 17a to 17c, and then moves further upward to be attached to the lower surfaces of the recording heads 17a to 17c.

[0017] FIG. 2 is a diagram showing the recording unit 9 of the printer 100 as viewed from above. The recording unit 9 includes a head housing 10 and line heads 11C, 11M, 11Y, and 11K held by the head housing 10. These line heads 11C to 11K are supported at a height such that a predetermined interval (for example, 1 mm) is formed with respect to the conveying surface 8a of a first conveying belt (conveyor belt) 8 stretched over a plurality of conveying rollers 7. In addition, the line heads 11C to 11K include a plurality of (three here) recording heads 17a to 17c arranged in a staggered manner along the paper width direction (Y1-Y2 direction) perpendicular to the paper conveying direction (A direction). The line heads 11C to 11K have a recording area equal to or larger than the width of the paper P being conveyed, and eject water-based ink (ink) from ejection nozzles 18 onto the paper P being conveyed by the first conveyor belt 8.

[0018] Fig. 3 is a side view of the recording head 17 constituting the line heads 11C to 11K of the recording unit 9, and Fig. 4 is a plan view of the recording heads 17a to 17c as viewed from the ink ejection surface F side. In Figs. 3 and 4, the recording heads 17a to 17c have the same shape and configuration, so the recording heads 17a to 17c are shown in a single diagram. The ink ejection surface F of the recording heads 17a to 17c is provided with a nozzle region R in which a large number of ejection nozzles 18 are arranged. In addition, a water-repellent film (not shown) is formed on the ink ejection surface F.

[0019] Four colors (cyan, magenta, yellow, and black) of ink stored in ink tanks (not shown) are supplied to the recording heads 17a to 17c constituting each of the line heads 11C to 11K for each color of the line heads 11C to 11K.

[0020] According to image data received from an external computer, each of the recording heads 17a to 17c ejects ink from ejection nozzles 18 toward the paper P that is adsorbed and held on the conveying surface of the first conveyor belt 8 and conveyed. As a result, a color image is formed on the paper P on the first conveyor belt 8 in which four colors of ink, cyan, magenta, yellow, and black, are superimposed.

[0021] In addition, in order to prevent poor ink ejection due to drying or clogging of the recording heads 17a to 17c, a purge is performed to push out ink with high viscosity from the ejection nozzles 18 of all recording heads 17a to 17c when printing begins after a long period of inactivity, and from the ejection nozzles 18 of recording heads 17a to 17c whose ink ejection volume is below a specified value between printing operations, in preparation for the next printing operation.

[0022] 2. Operation of the Recording Unit 9 with Respect to the First Conveying Unit 5 Fig. 5 is a perspective view showing the first transport section (transport section) 5 and a part of the recording section 9. Figs. 6 and 7 are explanatory views showing the operation of the recording section 9, and are cross-sectional views perpendicular to the axial direction (Y1-Y2 direction) of the transport roller 7. Fig. 6 shows the head housing 10 in the printing position, and Fig. 7 shows the head housing 10 in the maintenance position. In the following description, the paper width direction (Y1-Y2 direction) coincides with the axial direction of the transport roller 7.

[0023] In this embodiment, the ink ejection surface F is disposed parallel to the transport surface 8a of the first transport belt 8. Furthermore, the ink ejection surface F is inclined with respect to the horizontal direction (X1-X2 direction) in a cross section perpendicular to the axial direction (Y1-Y2 direction) of the transport roller 7. This narrows the space in which the first transport belt 8 and the head housing 10 are disposed in the left-right direction (X1-X2 direction), making it possible to reduce the size of the printer 100 in the left-right direction (X1-X2 direction).

[0024] The first transport section (transport unit) 5 has a first transport belt (transport belt) 8, multiple transport rollers 7, and a roller housing 6. The first transport belt 8 transports paper (recording medium) P in a paper transport direction A. The first transport belt 8 is stretched around the transport rollers 7. A pair of roller housings 6 are disposed on both outer sides of the transport rollers 7 in the axial direction, and are fixed to the printer body 1. The roller housing 6 may rotatably support the transport rollers 7.

[0025] Each roller housing 6 has a recess 62a formed by being recessed in the horizontal direction from a surface horizontally facing the head housing 10. The recess 62a is disposed opposite a protrusion 10c described later in the horizontal direction (X1-X2 direction).

[0026] Furthermore, guide rails 60a, 60b extending in the horizontal direction are fixed to each roller housing 6. The guide rails 60a, 60b are disposed axially outward of the first conveyor belt 8, and have guide holes 61a, 61b extending in the horizontal direction (X1-X2 direction).

[0027] The head housing 10 has a main body 101 and a side protrusion 102. The main body 101 is rectangular when viewed from the discharge direction B, and houses the line heads 11C, 11M, 11Y, and 11K therein. In this embodiment, the outer periphery of the main body 101 is disposed on the inside in the paper width direction (Y1-Y2 direction) of the first conveyor belt 8 (see FIG. 2).

[0028] The side protrusions 102 protrude from parts of both side surfaces of the main body 101 in the paper width direction (Y1-Y2 direction) outward in the paper width direction (Y1-Y2 direction) beyond the first conveyor belt 8 (see FIG. 2). The side protrusions 102 have guide protrusions 10a and 10b protruding from both side surfaces in the paper width direction (Y1-Y2 direction). The guide protrusions 10a and 10b are arranged parallel to the paper conveying direction A. In this embodiment, the side protrusions 102 are provided, but the side protrusions 102 do not have to be provided. In this case, the guide protrusions 10a and 10b are directly provided on both side surfaces of the main body 101 in the paper width direction (Y1-Y2 direction).

[0029] The guide protrusion 10a is fitted into the guide hole 61a, and the guide protrusion 10b is fitted into the guide hole 61b. As a result, the head housing 10 is supported by being sandwiched between the pair of guide rails 60a, 60b in the paper width direction (Y1-Y2 direction). The guide protrusions 10a, 10b slide within the guide holes 61a, 61b.

[0030] That is, the guide rails 60a, 60b support the head housing 10 so that it can move back and forth relative to the first transport belt (transport belt). In addition, by moving the head housing 10 along the guide rails 60a, 60b extending in the horizontal direction, the ink ejection surface F moves back and forth between a printing position (see FIG. 6) close to the transport surface 8a and a maintenance position (see FIG. 7) retreated from the transport surface 8a.

[0031] When the head housing 10 is in the printing position, a printing operation is performed. During the printing operation, water-based ink (ink) is ejected from the ejection nozzles 18 onto the paper P transported by the first transport belt 8. Furthermore, when the head housing 10 is in the maintenance position, a recovery operation is performed for the recording head 17. During the recovery operation, the maintenance unit 19 moves below the head housing 10 in the maintenance position. The recovery operation will be described in detail later.

[0032] Furthermore, on both side surfaces of the main body 101 in the paper width direction (Y1-Y2 direction), a convex portion 10c is formed closer to the first conveyor belt 8 than the side protrusion portion 102 (see Figs. 6 and 7). The tip of the convex portion 10c protrudes outward in the paper width direction (Y1-Y2 direction) than the first conveyor belt 8. The tip of the convex portion 10c is disposed opposite the roller housing 6 in the horizontal direction (X1-X2 direction). When the ink ejection surface F is disposed at the printing position, the convex portion 10c is disposed within the recess 62a. This makes it possible to prevent the head housing 10 including the ink ejection surface F from shifting in the paper conveyance direction A.

[0033] Each side protrusion 102 has a protrusion 103 that protrudes in the ink ejection direction B. That is, the head housing 10 has protrusions 103 that protrude in the ink ejection direction B. The protrusions 103 are arranged two by two on each side protrusion 102, side by side in the paper transport direction A. The protrusions 103 are arranged opposite the roller housing 6 in the horizontal direction (X1-X2 direction).

[0034] When the ink ejection surface F is placed at the printing position, the protrusion 103 comes into contact with the roller housing 6 and keeps the distance (e.g., 1 mm) between the ink ejection surface F and the transport surface 8a constant in the ejection direction B (see FIG. 6). This makes it possible to prevent the distance between the ink ejection surface F and the transport surface 8a from shifting.

[0035] It is preferable to determine the timing at which the ejection nozzles (nozzles) 18 eject ink onto the paper (recording medium) P based on the distance between the ink ejection surface F and the transport surface 8a when the ink ejection surface F is located at the printing position. This makes it possible to prevent a decrease in printing performance even if the distance between the ink ejection surface F and the transport surface 8a shifts when the head housing 10 is moved from the maintenance position to the printing position.

[0036] In addition, a drive motor (not shown) for moving the head housing 10 in the horizontal direction (X1-X2 direction) and a gear train (not shown) connected to the drive motor are provided outside the guide rails 60a and 60b. When the drive motor rotates, the gear train rotates, and the head housing 10 moves in the horizontal direction (X1-X2) between the printing position and the maintenance position.

[0037] 3. Recovery Operation of Recording Heads 17a to 17c 8 and 9 are explanatory diagrams illustrating the recovery operation of the recording heads 17a to 17c. In the printer 100, in order to clean the ink ejection surfaces F of the recording heads 17a to 17c, recovery operations are performed on all of the recording heads 17a to 17c when printing starts after a long period of inactivity and between printing operations, in preparation for the next printing operation.

[0038] When performing a recovery operation for the recording head 17, the head housing 10 is moved from the print position to the maintenance position, and the maintenance unit 19 is moved from the retracted position (see FIG. 1) to below the head housing 10.

[0039] Next, ink is supplied to the recording heads 17a to 17c. The supplied ink 22 is forcibly extruded (purged) from the ejection nozzles 18. This purging operation expels the viscous ink, foreign matter, and air bubbles from within the ejection nozzles 18, allowing the recording heads 17a to 17c to recover.

[0040] Next, a wiping operation is performed to wipe off the ink 22 discharged onto the ink ejection surfaces F. Specifically, as shown in Fig. 8, the unit lifting mechanism raises the maintenance unit 19, thereby pressing the wiper 35 against the wiping start position of the ink ejection surfaces F of the recording heads 17a to 17c.

[0041] Then, the wiper 35 wipes off the ink 22 pushed out onto the ink ejection surfaces F of the recording heads 17a to 17c. As shown in Fig. 9, after the wiper 35 moves to the downstream end of the ink ejection surfaces F of the recording heads 17a to 17c, the wiper 35 is retracted downward from the ink ejection surfaces F of the recording heads 17a to 17c.

[0042] Thereafter, the maintenance unit 19 is moved to the retreat position (see FIG. 1) from below the head housing 10. Next, the head housing 10 is moved from the maintenance position to the printing position.

[0043] Additionally, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention. For example, the number of ejection nozzles 18 of the recording heads 17a to 17c and the nozzle intervals can be appropriately set according to the specifications of the printer 100. The number of recording heads is also not particularly limited, and for example, one, two, or four or more recording heads 17 can be arranged for each of the line heads 11C to 11K. [Industrial Applicability]

[0044] The present invention can be used in an inkjet recording apparatus having nozzles that eject water-based ink onto a recording medium. [Explanation of symbols]

[0045] 1 Printer body 2 Paper Cassette 3 Paper feeder 4a First paper transport path 4b Second paper transport path 5 First belt conveyor (conveyor) 6 Roller housing 7 Transport roller 8 First conveyor belt (conveyor belt) 8a Conveying surface 9. Recording Section 10 Head housing 10a, 10b Guide protrusions 10c Convex part 11C, 11M, 11Y Line Head 11C~11K Line Head 12 Second belt conveyor 13 Registration roller pair 14 Decaler section 15 Paper output tray 17a~17c Recording head 18 Discharge nozzle (nozzle) 19 Maintenance Unit 22 Ink 30 Cap Units 35 Wiper 60a, 60b Guide rails 61a, 61b Guide holes 62a Recess 100 Printers 101 Main body 102 Side protrusion 103 Projection A Paper transport direction B Discharge direction F Ink ejection surface P paper R Nozzle Area

Claims

1. A conveying section including a conveying belt for conveying a recording medium and a conveying roller around which the conveying belt is stretched; a recording head having an ink ejection surface provided with a plurality of nozzles for ejecting ink onto the recording medium transported by the transport unit; a head housing for holding the recording head; a guide rail that supports the head housing so as to be reciprocally movable relative to the conveyor belt; In an inkjet recording apparatus comprising: the ink ejection surface is parallel to a conveying surface of the conveyor belt; the ink ejection surface is inclined with respect to a horizontal direction in a cross section perpendicular to an axial direction of the transport roller, An inkjet recording device in which, by moving the head housing along the guide rail extending horizontally, the ink ejection surface moves back and forth between a printing position close to the transport surface and a maintenance position retreated from the transport surface.

2. The conveying unit is A conveying roller around which the conveying belt is stretched; A roller housing disposed axially outward of the transport roller; having the head housing has a protruding portion that protrudes in a direction in which the ink is ejected, The inkjet recording apparatus according to claim 1 , wherein the protrusion contacts the roller housing when the ink ejection surface is disposed at the printing position, thereby maintaining a constant distance between the ink ejection surface and the transport surface.

3. the head housing has a protrusion that protrudes in a width direction of the storage medium perpendicular to the transport direction, The roller housing includes: a surface facing the head housing has a recess formed by being recessed in a horizontal direction; The inkjet recording apparatus according to claim 1 , wherein the convex portion is disposed within the concave portion when the ink ejection surface is disposed at the printing position.

4. 3. The inkjet recording device according to claim 1, wherein the timing at which the nozzles eject the ink onto the recording medium is determined based on the distance between the ink ejection surface and the transport surface when the ink ejection surface is positioned at the printing position.

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