Inkjet recording device

Abstract

To provide an inkjet recording device that can prevent dehydration of ink having dropped on a waste liquid tray.SOLUTION: An inkjet recording device includes: a recording head 37 provided with a nozzle surface in which a plurality of ink discharge ports are open downward; a wipe unit 53 for wiping off ink remaining in the ink discharge ports by performing a wiping operation of making a blade 71 contact the nozzle surface and move in a predetermined direction; a waste liquid tray 75 where ink wiped off by the wipe unit 53 drops; a cleaning liquid supply part 55 for supplying cleaning liquid to the waste liquid tray 75; a control part for executing a tray cleaning operation of cleaning the waste liquid tray 75 by supplying cleaning liquid to the waste liquid tray 75 from the cleaning liquid supply part 55; and a sealing member 111 for sealing a space including an ink dropping surface of the waste liquid tray 75.SELECTED DRAWING: Figure 7A

Description

[Technical field]

[0001] The present invention relates to an ink-jet image forming apparatus equipped with a wiping unit that wipes the ink ejection ports of a recording head. [Background technology]

[0002] As described in Patent Document 1, an inkjet recording device is equipped with a wiping unit that wipes the ink ejection ports of the nozzles of the recording head. The wiping unit has a blade that comes into contact with the nozzle surface where the ink ejection ports are open, and wipes the ink ejection ports by performing a wiping operation in which the blade moves from a movement start position to a movement end position. The wiped ink falls into a waste liquid tray located below the wiping unit, and is finally collected in a waste liquid tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-6640 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the inkjet recording device described in Patent Document 1, when the ink that has fallen into the waste liquid tray dries, it thickens and its fluidity decreases, causing problems such as the dried ink accumulating in the waste liquid tray and clogging the drain pipe connecting the waste liquid tray and the waste liquid tank with the dried ink.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above circumstances, an object of the present invention is to provide an inkjet recording apparatus capable of suppressing drying of ink that has fallen into a waste liquid tray. [Means for solving the problem]

[0006] In order to solve the above problems, the inkjet recording device of the present invention is characterized by comprising a recording head having a nozzle surface with a plurality of ink ejection ports opening downward, a wiping unit that wipes away ink remaining in the ink ejection ports by performing a wiping operation in which a blade is brought into contact with the nozzle surface and moved in a predetermined direction, a waste liquid tray into which the ink wiped off by the wiping unit falls, a cleaning liquid supply unit that supplies cleaning liquid to the waste liquid tray, a control unit that performs a tray cleaning operation in which the cleaning liquid supply unit supplies cleaning liquid to the waste liquid tray to clean the waste liquid tray, and a sealing member that seals a space including the ink drop surface of the waste liquid tray.

[0007] In the present invention, the liquid ejection apparatus may further include a waste liquid tray box in which the waste liquid tray is housed, and the sealing member may seal the waste liquid tray box.

[0008] In the present invention, the device may further include a communication part that connects the space sealed by the sealing member with the outside air, and the communication part may be a tubular member that penetrates the waste liquid tray box or the sealing member.

[0009] In the present invention, the cleaning liquid supply unit may include at least one of a tray cleaning liquid supply mechanism that supplies cleaning liquid directly to the waste liquid tray, and a head cleaning liquid supply mechanism that supplies cleaning liquid to the waste liquid tray via a cleaning liquid supply member that supplies cleaning liquid to be applied to the nozzle face of the recording head during the wiping operation, and may be characterized in that cleaning liquid is supplied to the waste liquid tray from at least one of the tray cleaning liquid supply mechanism and the head cleaning liquid supply mechanism.

[0010] In the present invention, the head cleaning liquid supply mechanism may be characterized in that it supplies cleaning liquid between a movement start position of the blade and the nozzle surface. Effect of the Invention

[0011] According to the present invention, the ink drop surface of the waste liquid tray is sealed off from the outside air by the sealing member, so that the ink contained in the dropped waste liquid is less likely to dry. [Brief description of the drawings]

[0012] [Figure 1] 1 is a front view showing a schematic internal structure of an inkjet recording apparatus according to an embodiment of the present invention; [Figure 2A] FIG. 2 is a plan view illustrating a head unit and a maintenance unit of the inkjet recording apparatus according to one embodiment of the present invention. [Figure 2B] FIG. 2 is a front view showing a schematic view of a head unit and a maintenance unit of the inkjet recording apparatus according to one embodiment of the present invention. [Figure 3A] 1 is a side view showing a recording head of an inkjet recording apparatus according to an embodiment of the present invention; [Figure 3B] FIG. 2 is a bottom view showing a print head of an inkjet printing apparatus according to an embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view showing a cap unit of the inkjet recording apparatus according to one embodiment of the present invention. [Figure 5A] FIG. 1 is a plan view showing a wiper unit integrated with a waste liquid tray (in a state where the carriage has moved to a movement start position) in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 5B] FIG. 1 is a plan view showing a wiper unit integrated with a waste liquid tray (in a state where the carriage has been moved to a movement end position) in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 6A] FIG. 1 is a plan view showing a schematic diagram of a wiping unit with a separate waste liquid tray (in a state where the carriage has moved to a movement start position) in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 6B] FIG. 11 is a plan view showing a schematic diagram of a wiping unit with a separate waste liquid tray (in a state where the carriage has moved to a movement end position) in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 7A] FIG. 2 is a side view showing a schematic diagram of a cleaning liquid supplying section corresponding to a wiping unit integrated with a waste liquid tray in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 7B] FIG. 2 is a plan view showing a schematic diagram of a cleaning liquid supplying section corresponding to a wiping unit integrated with a waste liquid tray in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 8A] FIG. 2 is a side view showing a schematic diagram of a cleaning liquid supplying section corresponding to a wiping unit with a separate waste liquid tray in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 8B] FIG. 2 is a plan view showing a schematic diagram of a cleaning liquid supplying section corresponding to a wiping unit with a separate waste liquid tray in an inkjet recording apparatus according to an embodiment of the present invention. [Figure 9] 1 is a side view showing a print head, and a cleaning liquid supplying member and a blade of a wiping unit that has been moved to a wiping position, in an inkjet printing apparatus according to an embodiment of the present invention. [Figure 10] 2 is a block diagram showing a control unit of the inkjet recording apparatus according to one embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an inkjet recording apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] First, the overall configuration of the inkjet recording apparatus 1 will be described with reference to Fig. 1, Fig. 2A, and Fig. 2B. Fig. 1 is a front view showing the inside of the inkjet recording apparatus 1. Fig. 2A is a plan view showing the head unit 11 and the maintenance unit 13, and Fig. 2B is a side view showing the head unit 11 and the maintenance unit 13. Hereinafter, the front side of the paper in Fig. 1 is the front side (front side) of the inkjet recording apparatus 1. In each figure, U, Lo, L, R, Fr, and Rr respectively indicate top, bottom, left, right, front, and rear.

[0015] As shown in FIG. 1, the inkjet recording device 1 is an inkjet type image forming device that forms an image by ejecting ink. The inkjet recording device 1 includes a rectangular parallelepiped main housing 3. A paper feed cassette 5 that stores sheets such as plain paper and coated paper, and a paper feed roller 7 that feeds the sheets from the paper feed cassette 5 are provided at the bottom inside the main housing 3. A transport unit 9 that transports the sheets is provided above the paper feed cassette 5. Four head units 11M, 11C, 11Bk, and 11Y (collectively referred to as head units 11) and four maintenance units 13 are provided above the transport unit 9 (see also FIGS. 2A and 2B). A pair of discharge rollers 15 that discharges the sheets on which images have been formed, and a discharge tray 17 on which the discharged sheets are stacked are provided at the upper left portion of the main housing 3.

[0016] Inside the main body housing 3, a transport path 19 is provided that extends from the paper feed cassette 5 through the transport unit 9 to the discharge roller pair 15. The transport path 19 is provided with a plurality of transport roller pairs 21 that transport the sheet S.

[0017] Next, the conveying unit 9 will be described with reference to FIG. 1. The conveying unit 9 includes an endless conveying belt 25. The conveying belt 25 has a large number of through holes penetrating in the thickness direction. The conveying belt 25 is wound around a driving roller 27A and a driven roller 27B that are arranged spaced apart from each other on the left and right. The driving roller 27A is driven to rotate by a motor (not shown). The rotation of the driving roller 27A causes the conveying belt 25 to run in the counterclockwise direction in FIG. 1. The conveying belt 25 running along the upper track forms a conveying path 19 along which the sheet is conveyed in the conveying direction from right to left in FIG. 1.

[0018] A conveying plate 29 and a suction device 31 are provided in the hollow portion of the conveying belt 25. The conveying plate 29 has a large number of through holes penetrating in the thickness direction. The conveying plate 29 comes into contact with the inner surface of the conveying belt 25 that runs along the upper track. The suction device 31 is provided below the conveying plate 29 and attracts the sheet S to the conveying belt 25 by sucking air through the through holes of the conveying belt 25 and the conveying plate 29.

[0019] Next, the head unit 11 will be described. The four head units 11Y, 11Bk, 11C, and 11M correspond to yellow, black, cyan, and magenta inks, respectively, and are arranged above the transport unit 9 at predetermined intervals along the transport direction. Ink containers 33Y, 33Bk, 33C, and 33M filled with yellow, black, cyan, and magenta inks, respectively, are connected to the four head units 11. Each head unit 11 includes three recording heads 37 and a plate 39 that supports the three recording heads 37, as shown in Figures 2A and 2B.

[0020] The recording head 37 will be described with reference to Figs. 3A and 3B. Fig. 3A is a side view of the recording head 37, and Fig. 3B is a bottom view of the recording head 37. The recording head 37 has a rectangular parallelepiped shape that is long in the width direction (front-rear direction) that intersects with the sheet conveying direction. The recording head 37 has a large number of nozzles (not shown) to which ink is supplied, and a piezoelectric element (not shown) provided for each nozzle. The ejection openings of the large number of nozzles open on the bottom surface of the recording head 37. When the piezoelectric element is driven, the ink in the nozzles is ejected downward from the ejection openings. As shown in Fig. 3B, the surface including the area N where the ejection openings are opened is called the nozzle surface N.

[0021] The three recording heads 37 are arranged in a staggered manner along the width direction (front-rear direction) as shown in Fig. 2A. In detail, two recording heads 37 are arranged side by side in the width direction, and one recording head 37 is arranged adjacent to the two recording heads 37 in the transport direction. The recording heads 37 are supported such that their lower ends protrude from the plate 39 as shown in Fig. 3A.

[0022] Each of the four head units 11 is supported by a head unit lifting mechanism 41 (see FIG. 10) so as to be movable up and down between a printing position and a retracted position. The printing position is a position where the nozzle surface N of the recording head 37 of the head unit 11 faces the conveyor belt 25 running along the upper track with a predetermined gap (for example, 1 mm) therebetween (see FIG. 1). The retracted position is a position where the nozzle surface N of the recording head 37 of the head unit 11 is spaced above the conveyor belt 25 from the printing position, forming a space above the conveyor unit 9 that can accommodate a cap unit 51 and a wipe unit 53 of the maintenance unit 13, which will be described later. The head unit lifting mechanism 41 is electrically connected to the control unit 201 (see FIG. 10).

[0023] Next, the maintenance units 13 will be described. The four maintenance units 13 have the same structure, and are provided for each of the four head units 11. The maintenance units 13 are disposed adjacent to the corresponding head units 11 in the transport direction. In this example, the maintenance units 13 are disposed adjacent to the downstream side (left side) of the corresponding head units 11.

[0024] As shown in FIG. 2B, the maintenance unit 13 includes a cap unit 51 that covers the nozzle surfaces N of the three recording heads 37 of the head unit 11, a wiping unit 53 that cleans the nozzle surfaces N of the three recording heads 37 of the head unit 11, and a cleaning liquid supply section 55 that supplies cleaning liquid to the wiping unit 53.

[0025] The cap unit 51, the wipe unit 53, and the cleaning liquid supply unit 55 are supported by a housing 57. The housing 57 is disposed downstream (on the left side) of the corresponding head unit 11. The housing 57 has a hollow rectangular parallelepiped shape that is long in the width direction, and the surface facing the corresponding head unit 11 (the right surface) is open.

[0026] First, the cap unit 51 will be described with reference to Fig. 4. Fig. 4 is a perspective view showing the cap unit 51. The cap unit 51 includes three caps 61 that cover the nozzle faces N of the three recording heads 37. The three caps 61 are arranged in a staggered manner along the width direction to correspond to the three recording heads 37 of the head unit 11, and are supported by a support plate 63. Each cap 61 includes a recess 61a with an open top surface, and an outlet (not shown) provided at the bottom of the recess 61a.

[0027] The cap unit 51 can be moved in the transport direction and the opposite direction (left and right) between a standby position (see FIGS. 1, 2A, and 2B) and a capping position by a capping unit moving mechanism (not shown). The standby position is a position where the capping unit 51 is accommodated in the lower space of the housing 57. The capping position is a position where the capping unit 51 is accommodated in the space below the head unit 11 that has risen to the retracted position. When the capping unit 51 moves to the capping position and the head unit 11 descends to a predetermined height, the nozzle surfaces N of the three recording heads 37 are covered with the three caps 61. The capping unit 51 can be moved between the capping position and the standby position through a right opening of the housing 57.

[0028] Next, the wiping unit 53 and the cleaning liquid supplying part 55 will be described with reference to Figs. 5A, 5B, 6A, 6B, 7A, 7B, 8A, and 8B. Figs. 5A and 5B are plan views typically showing the wiping unit 53 with an integrated waste liquid tray, and Figs. 6A and 6B are plan views typically showing the wiping unit 53 with a separate waste liquid tray. Figs. 7A and 7B are side and plan views typically showing the wiping unit 53 with an integrated waste liquid tray and the cleaning liquid supplying part 55. Figs. 8A and 8B are side and plan views typically showing the wiping unit 53 with a separate waste liquid tray and the cleaning liquid supplying part 55.

[0029] First, the wiping unit 53 will be described with reference to Figures 5A, 5B, 6A, and 6B. The wiping unit 53 includes three blades 71 that wipe the nozzle faces N of the three recording heads 37, three cleaning liquid supplying members 73 that supply cleaning liquid to be applied to the nozzle faces N of the three recording heads 37, a waste liquid tray 75 (75A, 75B) that supports the three blades 71 and the three cleaning liquid supplying members 73 and into which the wiped ink and cleaning liquid fall, and a waste liquid tray box 77 in which the waste liquid tray 75 is housed.

[0030] First, the waste liquid tray 75 will be described. The waste liquid tray 75 has a bottom plate and side plates provided along the outer periphery of the bottom plate. The waste liquid tray 75 includes two types: an integrated waste liquid tray 75A (see Figs. 5A, 5B, 7A, and 7B) and a split type waste liquid tray 75B (see Figs. 6A, 6B, 8A, and 8B). As shown in Figs. 5A and 5B, 7A, and 7B, one integrated waste liquid tray 75A is provided to correspond to all three recording heads 37. That is, as shown in Figs. 5A and 5B, the integrated waste liquid tray 75A has a long rectangular portion 75x long in the width direction corresponding to two recording heads 37 arranged in the width direction in a plan view, and a short rectangular portion 75y corresponding to one recording head 37 and having a length in the width direction shorter than that of the long rectangular portion 75x.

[0031] On the other hand, as shown in Figures 6A and 6B, 8A and 8B, three separate waste liquid trays 75B are provided corresponding to the three recording heads 37. That is, as shown in Figures 6A and 6B, each separate waste liquid tray 75B is formed in a rectangular shape that is long in the width direction in plan view, corresponding to one recording head 37.

[0032] The waste liquid tray 75 includes three rails 81 that guide the blade 71 in the front-rear direction. The three rails 81 are longer than the nozzle surface N of the recording head 37, and are arranged to correspond to the three recording heads 37. That is, in the case of the integrated waste liquid tray 75A, as shown in Figs. 5A and 5B, two rails 81 are arranged in a row in the front-rear direction in the long rectangular portion 75x, and one rail is arranged in the short rectangular portion 75y. In the case of the split waste liquid tray 75B, as shown in Figs. 6A and 6B, one rail 81 is arranged in each of the three waste liquid trays 75B.

[0033] As shown in FIG. 7A and FIG. 8A, a drain port 83 is formed in the bottom plate of the waste liquid tray 75 (75A, 75B). The drain port 83 is disposed in the approximate center of the bottom plate. The bottom plate is formed so as to incline downward toward the drain port 83. The drain port 83 is connected to the waste liquid tank 87 via a drain pipe 85. The drain pipe 85 is provided with a drain pump 89. The waste liquid tank 87 and the drain pump 89, and the drain pipe 85 between the waste liquid tank 87 and the drain pump 89 are fixed near the housing 57. On the other hand, the drain pipe 85 between the drain port 83 and the drain pump 89 is flexible and has a predetermined length as described later. The drain pump 89 is electrically connected to the control unit 201 (see FIG. 10).

[0034] Next, the blades 71 will be described. The blades 71 are plate-like members having a width greater than the width of the nozzle surface N of the recording head 37, and are made of flexible resin or the like. The lower ends of the three blades 71 are each supported by a carriage 91 (see FIGS. 5A to 6B).

[0035] As shown in Figures 5A to 6B, the carriage 91 engages with rails 81 provided on the waste liquid tray 75, and can be moved in the width direction (front-rear direction) between a movement start position (see Figures 5A and 6A) and a movement end position (see Figures 5B and 6B) by a carriage movement mechanism 93 (see Figure 10). The direction from the movement start position to the movement end position (in this example, the direction from front to rear) is defined as the movement direction (also called the wiping direction) of the carriage 91. The carriage movement mechanism 93 is electrically connected to the control unit 201 (see Figure 10).

[0036] Next, the cleaning liquid supply member 73 will be described. As shown in FIG. 5A and FIG. 6A, the cleaning liquid supply member 73 is disposed behind the movement start position of the carriage 91 in the movement direction, and is supported immovably by the waste liquid tray 75. The cleaning liquid supply member 73 has a supply part extending forward in the movement direction of the carriage 91. The supply part is formed with a cleaning liquid supply hole 95 penetrating in the vertical direction. The cleaning liquid is supplied to this cleaning liquid supply hole 95 from a head cleaning liquid supply mechanism 115 described later. The lower surface of the supply part where the cleaning liquid supply hole opens is the supply surface of the cleaning liquid. When the carriage 91 has moved to the movement start position (see FIG. 5A and FIG. 6A), the supply part extends forward passing above the blade 71, and the cleaning liquid supply hole 95 is located forward of the blade 71 in the movement direction. Since the cleaning liquid supplying member 73 is supported immovably by the waste liquid tray 75 as described above, the cleaning liquid supplying member 73 does not move even if the carriage 91 moves (see FIGS. 5B and 6B).

[0037] Next, the waste liquid tray box 77 will be described. As shown in Figs. 5A, 5B, 6A, 6B, 7A, and 8A, the waste liquid tray box 77 is a rectangular box-shaped member with an open top, having a space capable of accommodating the waste liquid tray 75 (including the blade 71 and the cleaning liquid supply member 73 supported by the waste liquid tray 75). In the case of the integrated waste liquid tray 75A, as shown in Figs. 5A, 5B, and 7A, the waste liquid tray box 77 accommodates one waste liquid tray 75A. In the case of the split waste liquid tray 75B, as shown in Figs. 6A, 6B, and 8A, the waste liquid tray box 77 accommodates three waste liquid trays 75B. As shown in Figs. 7A and 8A, the drain pipe 85 between the drain port 83 and the drain pump 89 penetrates the bottom plate of the waste liquid tray box 77. The waste liquid tray box 77 is not limited to a rectangular box shape, and may have a shape that fits the outer periphery of the waste liquid tray 45 .

[0038] The wiping unit 53 (blade 71, cleaning liquid supply member 73, waste liquid tray 75, waste liquid tray box 77) can be moved in the transport direction and the opposite direction (left and right direction) between a standby position (see FIG. 2B) and a wiping position by a wiping unit moving mechanism 101 (see FIG. 10). The standby position is a position where the wiping unit 53 is accommodated in the upper space of the housing 57. The wiping position is a position where the wiping unit 53 is accommodated in the space below the head unit 11 that has risen to the retracted position. After the head unit 11 moves to the retracted position, the wiping unit 53 moves to the wiping position, and the head unit 11 descends to a predetermined height, so that the blade 71 can come into contact with the nozzle surface N of the recording head 37. The wiping unit 53 can move between the standby position and the wiping position through the right opening of the housing 57. The wiping unit moving mechanism 101 is electrically connected to a control unit 201 (see FIG. 10).

[0039] In this manner, the wipe unit 53 moves between the standby position and the wiping position. For this reason, as described above, the waste liquid tank 87 and the drain pump 89, and the drain pipe 85 between the waste liquid tank 87 and the drain pump 89 are fixed near the standby position of the wipe unit 53 (near the housing 57). On the other hand, the drain pipe 85 between the drain pump 89 and the drain port 83 is flexible as described above, and has a length longer than the moving distance of the wipe unit 53. Therefore, when the wipe unit 53 moves to the wiping position, the drain pipe 85 between the drain pump 89 and the drain port 83 extends almost straight. On the other hand, when the wipe unit 53 moves to the standby position, the drain pipe 85 between the drain pump 89 and the drain port 83 is curved in a zigzag or spiral shape.

[0040] Next, the cleaning liquid supply unit 55 will be described with reference to Figures 7A, 7B, 8A and 8B. The cleaning liquid supply unit 55 has a sealing member 111 that seals the opening on the top surface of the waste liquid tray box 77, a cleaning liquid tank 113, and a head cleaning liquid supply mechanism 115 and a tray cleaning liquid supply mechanism 117 that are provided between the cleaning liquid tank 113 and the sealing member 111.

[0041] First, the sealing member 111 will be described. As shown in Fig. 7B and Fig. 8B, the sealing member 111 is a rectangular plate-like member having dimensions capable of sealing the opening on the top surface of the waste liquid tray box 77. The sealing member 111 is supported by the housing 57 so as to be movable between an open position and a closed position by a sealing member lifting mechanism 121 (see Fig. 10). When the sealing member 111 rises to the open position, the opening on the top surface of the waste liquid tray box 77 is opened, and when the sealing member 111 descends to the closed position, the opening on the top surface of the waste liquid tray box 77 is closed. The sealing member lifting mechanism 121 is electrically connected to the control unit 201 (see Fig. 10).

[0042] The sealing member 111 has three first supply ports 125 for head cleaning and multiple second supply ports 127 for tray cleaning (two in the case of the integrated waste liquid tray 75A (see FIG. 7B) and three in the case of the split waste liquid tray 75B (see FIG. 8B)) formed therein, which penetrate through the sealing member 111 in the thickness direction. The three first supply ports 125 are arranged to correspond to the cleaning liquid supply holes 95 of the three cleaning liquid supply members 73 of the wiping unit 53 that has moved to the standby position. Cleaning liquid is supplied to the cleaning liquid supply holes 95 through the three first supply ports 125.

[0043] In the case of the integrated waste liquid tray 75A, the two second supply ports 127 are arranged to correspond to the front ends of the long rectangular portion 75x and the short rectangular portion 75y of the waste liquid tray 75A of the wiping unit 53 that has moved to the standby position, as shown in Fig. 7B. In the case of the split waste liquid tray 75B, the three second supply ports 127 are arranged to correspond to the front ends of the three waste liquid trays 75B, as shown in Fig. 8B. The second supply ports 127 may have a shape that faces a predetermined position on the bottom plate of the waste liquid tray 75, or may have a shape that allows the cleaning liquid to be sprayed in a shower-like manner.

[0044] Next, the cleaning liquid tank 113 will be described. Cleaning liquid is stored in the cleaning liquid tank 113. The cleaning liquid is, for example, a liquid containing a solvent and water as main components, which is ink except for coloring materials. Furthermore, surfactants, preservatives, etc. may be added as necessary.

[0045] Next, a description will be given of the head cleaning liquid supply mechanism 115. The head cleaning liquid supply mechanism 115 includes a pipe 131 that connects the three first supply ports 125 formed in the sealing member 111 to the cleaning liquid tank 113, and a first pump 133 provided in the pipe 131.

[0046] 7A and 7B, 8A and 8B, in both types of waste liquid trays 75, the pipes 131 include a main pipe extending horizontally from the cleaning liquid tank 113, two first branch pipes branching off from the main pipe via a first Y-shaped joint 137, and two second branch pipes branching off from one of the first branch pipes via a second Y-shaped joint 139. The tips of the other first branch pipe and the two second branch pipes are bent downward at approximately a right angle and connected to three first supply ports 125 formed in the sealing member 111.

[0047] The first pump 133 is provided in the main piping and pumps up the cleaning liquid from the cleaning liquid tank 113 to the piping 131. The pumped up cleaning liquid is sent to the three first supply ports 125 through the piping 131. The first pump 133 is electrically connected to the control unit 201 (see FIG. 10).

[0048] In addition, since the lengths of the piping 131 from the first pump 133 to the three first supply ports 125 are different, the diameter, etc. of the piping 131 are set so that the amount of cleaning liquid supplied from each first supply port 125 (amount supplied per unit time) is the same.

[0049] Next, a description will be given of the tray cleaning liquid supply mechanism 117. The tray cleaning liquid supply mechanism 117 includes a pipe 141 that connects the cleaning liquid tank 113 to the multiple second supply ports 127 formed in the sealing member 111, and a second pump 143 provided in the pipe 141.

[0050] 7A and 7B, in the case of the integrated waste liquid tray 75A, the piping 141 has a main pipe extending horizontally from the cleaning liquid tank 113, and two first branch pipes branching off from the main pipe via Y-joints 145 (see FIG. 7B). The tips of the two first branch pipes are bent downward at approximately a right angle and connected to two second supply ports 127 formed in the sealing member 111.

[0051] 8A and 8B, in the case of the split type waste liquid tray 75B, the pipe 141 has a main pipe extending horizontally from the cleaning liquid tank 113, two first branch pipes branching off from the main pipe via a first Y-shaped joint 145, and two second branch pipes branching off from one of the first branch pipes via a second Y-shaped joint 147. The tips of the other first branch pipe and the two second branch pipes are bent downward at approximately a right angle and connected to three second supply ports 127 formed in the sealing member 111.

[0052] The second pump 143 is provided in the main piping and pumps up the cleaning liquid from the cleaning liquid tank 113. The pumped up cleaning liquid is sent to the multiple second supply ports 127 through the piping 141. The second pump 143 is electrically connected to the control unit 201 (see FIG. 10).

[0053] In addition, since the lengths of the pipes 141 from the second pump 143 to each of the second supply ports 127 are different, the diameters of the pipes 141, etc. are set so that the amount of cleaning liquid supplied from each of the second supply ports 127 is the same.

[0054] As described above, the sealing member 111 is supported by the housing 57 so as to be movable up and down, but the cleaning liquid tank 113, the first pump 133, and the second pump 143 are supported near the housing 57 so as to be immovable.

[0055] Next, the control unit 201 will be described with reference to the block diagram of Fig. 10. The control unit 201 executes a printing operation for forming an image on a sheet, a head cleaning operation for cleaning the recording head 37 of the head unit 11, and a tray cleaning operation for cleaning the waste liquid tray 75. A description of the operation of the control unit 201 in the printing operation will be omitted.

[0056] The control unit 201 controls the head unit lifting mechanism 41 to lift and lower the head unit 11 between the retracted position and the printing position. Furthermore, it is also possible to lift and lower the head unit 11 to a cleaning position between the printing position and the retracted position.

[0057] Furthermore, the control unit 201 controls the carriage moving mechanism 93 to move the carriage 91 to the movement start position and the movement end position.

[0058] Furthermore, the control unit 201 controls the wipe unit moving mechanism 101 to move the wipe unit 53 between the standby position and the wipe position.

[0059] Furthermore, the control unit 201 controls the drain pump 89 to pump the waste liquid that has fallen into the waste liquid tray 75 through the drain pipe 85 to the waste liquid tank 87 .

[0060] Furthermore, the control unit 201 controls the first pump 133 to pump the cleaning liquid from the cleaning liquid tank 113 to the piping 131 of the head cleaning liquid supply mechanism 115. Furthermore, the control unit 201 controls the second pump 143 to pump the cleaning liquid from the cleaning liquid tank 113 to the piping 141 of the tray cleaning liquid supply mechanism 117.

[0061] Furthermore, the control unit 201 controls the sealing member lifting mechanism 121 to lift and lower the sealing member 111 between the closed position and the open position.

[0062] Next, the printing operation, head cleaning operation, and tray cleaning operation of the inkjet recording apparatus 1 having the above configuration will be described.

[0063] First, the printing operation will be described with reference to Fig. 1. During printing operation, the head unit 11 descends to the printing position, and the cap unit 51 and the wiping unit 53 move to the standby position. The sealing member 111 descends to the closed position to seal the opening on the top surface of the waste liquid tray box 77. The three first supply ports 125 formed in the sealing member 111 communicate with the cleaning liquid supply holes 95 of the three cleaning liquid supply members 73 of the wiping unit 53.

[0064] First, a sheet is fed from the paper feed cassette 5 by the paper feed roller 7. The fed sheet is transported by the transport roller pair 21 along the transport path 19 to the transport unit 9. The sheet is transported along the upper track of the transport belt 33 of the transport unit 9. At this time, ink is ejected onto the sheet from the recording head 37 of the head unit 11 corresponding to the image data, forming an image on the sheet. Thereafter, the sheet is transported along the transport path 19 by the transport roller pair 21, and discharged onto the discharge tray 17 by the discharge roller pair 15.

[0065] After the printing operation is completed, the head cleaning operation is performed (the capping operation will not be described). As described above, the wiping unit 53 moves to the standby position. The opening on the top surface of the waste liquid tray box 77 is sealed by the sealing member 111. The three first supply ports 125 formed in the sealing member 111 communicate with the cleaning liquid supply holes 95 of the three cleaning liquid supply members 73 of the wiping unit 53.

[0066] First, the control unit 201 controls the head unit lifting mechanism 41 to lift the head unit 11 to the retracted position.

[0067] Thereafter, the control unit 103 controls the first pump 133 of the head cleaning liquid supply mechanism 115 to pump up the cleaning liquid from the cleaning liquid tank 113 to the pipe 131. The cleaning liquid is supplied from the pipe 131 through the three first supply ports 125 to the cleaning liquid supply holes 95 of the three cleaning liquid supply members 73. The control unit 201 drives the first pump 133 to pump up the cleaning liquid until the supplied cleaning liquid is held in a state of protruding in a hemispherical shape from the cleaning liquid supply hole 95, and then stops driving the first pump 133. Note that the cleaning liquid forms a concave meniscus inside the cleaning liquid supply hole 95 and is held inside during operations other than the head cleaning operation.

[0068] Thereafter, the control unit 201 controls the sealing member lifting mechanism 121 to lift the sealing member 111 to the open position, and then controls the wiping unit moving mechanism 101 to move the wiping unit 53 (blade 71, cleaning liquid supplying member 73, waste liquid tray 75, waste liquid tray box 77) from the standby position to the wiping position. At this time, the cleaning liquid supplying member 73 moves with the cleaning liquid protruding from the cleaning liquid supply hole 95 in a semi-spherical shape. Thereafter, the control unit 201 controls the head unit lifting mechanism 41 to lower the head unit 11 to the cleaning position. As a result, the nozzle surface N of each recording head 37 is lowered to the same height position as the cleaning machine supply surface of the cleaning liquid supplying member 73 in front of each cleaning liquid supplying member 73 of the wiping unit 53, and the nozzle surface N and the cleaning liquid supplying surface are continuous with almost no gap (see FIG. 9). In this way, the cleaning liquid is supplied between the movement start position of the carriage 91 (blade 71) and the nozzle surface N.

[0069] After that, the control unit 201 controls the carriage movement mechanism 93 to move the carriage 91 from the movement start position to the movement end position. This performs a wiping operation in which the blade 71 moves along the nozzle surface N through the supply surface of the cleaning liquid supply member 73. This wiping operation causes the blade 71 to wipe off the ink remaining on the nozzle surface N together with the cleaning liquid supplied to the supply surface. The wiped off ink and cleaning liquid drop from the lower end edge and side edges of the blade 71 into the waste liquid tray 75 below. Specifically, the waste liquid (ink and cleaning liquid) drops onto the inner surface of the waste liquid tray 75 (the upper surface of the bottom plate and the inner surfaces of the side plates, which correspond to the ink drop surface of the present invention). This completes the head cleaning operation.

[0070] Thereafter, the control unit 201 controls the head unit lifting mechanism 41 to raise the head unit 11 to the standby position, controls the carriage moving mechanism 93 to move the carriage 91 to the movement start position, and then controls the wipe unit moving mechanism 101 to move the wipe unit 53 from the wipe position to the standby position.

[0071] After the head cleaning operation is thus completed, the control unit 201 executes a tray cleaning operation at a predetermined timing. The control unit 201 first controls the sealing member lifting mechanism 121 to lower the sealing member 111 to the closed position. This closes the opening on the top surface of the waste liquid tray box 77. At the same time, the three first supply ports 125 provided in the sealing member 111 communicate with the cleaning liquid supply holes 95 of the three cleaning liquid supply members 73 of the wiping unit 53.

[0072] Thereafter, the control unit 201 controls the first pump 133 of the head cleaning liquid supply mechanism 115 and the second pump 143 of the tray cleaning liquid supply mechanism 117 to pump the cleaning liquid from the cleaning liquid tank 113 to the pipes 131 and 141. In the head cleaning liquid supply mechanism 115, the cleaning liquid is supplied from the three first supply ports 125 to the three cleaning liquid supply holes 95 through the pipe 131, and is discharged from the three cleaning liquid supply holes 95 toward the waste liquid tray 75. In the tray cleaning liquid supply mechanism 117, the cleaning liquid is discharged from the multiple second supply ports 127 through the pipe 141 toward the waste liquid tray 75.

[0073] In the case of the integrated waste liquid tray 75A, the three first supply ports 125 (cleaning liquid supply holes 95) and two second supply ports 127 are arranged at the front end, a portion slightly rearward from the center, and the rear end of the long rectangular portion 75x of the waste liquid tray 75A, and at the front end and rear end of the short rectangular portion 75y, as shown in Fig. 7B, so that the cleaning liquid discharged from the three first supply ports 125 and the two second supply ports 127 spreads over almost the entire surface of the bottom plate of the waste liquid tray 75A. Then, the ink and cleaning liquid that have dropped from the blade 71 or splashed around flow along the bottom plate toward the drain port 83 (see Fig. 7A) together with the discharged cleaning liquid.

[0074] In the case of the split waste liquid tray 75B, the first supply port 125 (cleaning liquid supply hole 95) and the second supply port 127 are disposed at the front and rear ends of each waste liquid tray 75B as shown in Fig. 8B, so that the cleaning liquid discharged from the first supply port 125 and the second supply port 127 spreads over almost the entire surface of the bottom plate of the waste liquid tray 75B. Then, the ink and cleaning liquid that have dropped from the blade 71 or splashed around flow along the bottom plate toward the drain port 83 together with the discharged cleaning liquid.

[0075] When a predetermined amount of waste liquid (wiped ink and cleaning liquid) is stored in the waste liquid tray 75 and the drain pipe 85, the control unit 201 drives the drain pump 89 to send the stored waste liquid through the drain pipe 85 to the waste liquid tank 87. This completes the tray cleaning operation.

[0076] As described above, according to the inkjet recording apparatus 1 of this embodiment, when the wiping unit 53 moves to the standby position, the opening on the top surface of the waste liquid tray box 77 is sealed by the sealing member 111, so that the ink drop surface of the waste liquid tray 75 (the top surface of the bottom plate and the inner surfaces of the side plates) is blocked from the outside air. Therefore, the ink contained in the dropped waste liquid is less likely to dry due to the outside air, so that accumulation of dried ink in the waste liquid tray 75 and clogging of the drain pipe 85 due to dried ink can be prevented.

[0077] 7A and 8A, the sealing member 111 may be provided with a small-diameter tubular member 151. The tubular member 151 passes through an opening formed in the sealing member 111 and extends into the space surrounded by the waste liquid tray box 77 and the sealing member 111. In this manner, the tubular member 151 is an example of a communication part in the present invention that communicates the space sealed by the sealing member 111 with the outside air. When the waste liquid tray box 77 is sealed with the sealing member 111, the volume of the sealed space may change due to temperature changes or the like. Therefore, by providing the tubular member 151, the space communicates with the outside air through the tubular member 151, so that the volume change of the space can be prevented. Although a small-diameter opening may be formed in the sealing member 111 or the waste liquid tray box 77, the provision of the small-diameter tubular member 151 makes it possible to accommodate the volume change of the closed space while maintaining the blocking performance of the ink drop surface of the waste liquid tray 75 from the outside air. Moreover, the tubular member 151 may be provided in the waste liquid tray box 77. Moreover, it is preferable that the tubular member 151 is a single piece.

[0078] Also, a seal member may be provided along the outer periphery of the top opening of the waste liquid tray box 77. In this case, when the top opening of the waste liquid tray box 77 is sealed with the sealing member 111, the airtightness of the space surrounded by the sealing member 111 and the waste liquid tray box 77 is improved.

[0079] In the above embodiment, the waste liquid tray box 77 is sealed with the sealing member 111, but the opening on the top surface of the waste liquid tray 75 may also be sealed with the sealing member 111. However, the waste liquid tray 75 is provided with the carriage 91, the rails 81 supporting the carriage 91, and the like, as described above. In particular, the rails 81 may be formed along the edge of the side plate of the waste liquid tray 75. Since it is difficult to seal the waste liquid tray 75 with the sealing member 111 in this way, it is preferable to provide a waste liquid tray box 77 in which the waste liquid tray 75 is housed, and to seal the opening on the top surface of the waste liquid tray box 77 with the sealing member 111.

[0080] In the above embodiment, the cleaning liquid supply unit 55 includes the head cleaning liquid supply mechanism 115 and the tray cleaning liquid supply mechanism 117, and cleaning liquid is supplied from the head cleaning liquid supply mechanism 115 and the tray cleaning liquid supply mechanism 117 during the tray cleaning operation. The first supply port 125 of the head cleaning liquid supply mechanism 115 and the second supply port 127 of the tray cleaning liquid supply mechanism 117 are arranged in a dispersed manner on the waste liquid tray 75, so that the cleaning liquid can be supplied to almost the entire surface of the bottom plate of the waste liquid tray 75. Therefore, the ink that has dropped or splashed into the waste liquid tray 75 during the head cleaning operation can be reliably collected together with the cleaning liquid from the waste liquid tray 75 through the drain port 83 to the waste liquid tank 87 during the tray cleaning operation. However, cleaning liquid may be supplied from either the head cleaning liquid supply mechanism 115 or the tray cleaning liquid supply mechanism 117 during the tray cleaning operation.

[0081] Furthermore, in the present embodiment, an example has been described in which a maintenance unit 13 is provided for each head unit 11, but one maintenance unit 13 may be provided for four head units 11. In this case, four cap units 51, four wiping units 53, and a cleaning liquid supply unit 55 are provided in one maintenance unit 13. The four cap units 51 move between a cap position and a standby position, and the four wiping units 53 and the cleaning liquid supply unit 55 move between a wiping position and a standby position.

[0082] Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above embodiments, and those skilled in the art may modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of symbols]

[0083] 1 Inkjet recording device 37 Recording head 53 Wipe Unit 55 Cleaning liquid supply unit 75 (75A, 75B) Waste Tray 77 Waste Tray Box 111 Sealing member 115 Head cleaning fluid supply mechanism 117 Tray cleaning liquid supply mechanism 151 Tubular member (communicating part) 201 Control section N Nozzle surface

Claims

1. a recording head provided with a nozzle surface having a plurality of ink ejection ports facing downward; a wiping unit that performs a wiping operation by bringing a blade into contact with the nozzle surface and moving it in a predetermined direction to wipe off ink remaining in the ink ejection ports; a waste liquid tray into which the ink wiped by the wiping unit falls; a cleaning liquid supply unit for supplying a cleaning liquid to the waste liquid tray; a control unit that executes a tray cleaning operation in which the cleaning liquid supply unit supplies a cleaning liquid to the waste liquid tray to clean the waste liquid tray; a sealing member that seals a space including the ink drop surface of the waste liquid tray.

2. The liquid discharge tray further includes a waste liquid tray box in which the waste liquid tray is accommodated, 2. The inkjet recording apparatus according to claim 1, wherein the sealing member seals the waste liquid tray box.

3. A communication part that communicates the space sealed by the sealing member with outside air, 3. The ink jet recording apparatus according to claim 1, wherein the communication portion is a tubular member that penetrates the waste liquid tray box or the sealing member.

4. The cleaning liquid supply unit includes: a tray cleaning liquid supply mechanism that directly supplies a cleaning liquid to the waste liquid tray; a head cleaning liquid supply mechanism that supplies cleaning liquid to the waste liquid tray via a cleaning liquid supply member that supplies cleaning liquid to be applied to the nozzle surface of the recording head during the wiping operation, 3. The inkjet recording apparatus according to claim 1, wherein cleaning liquid is supplied to the waste liquid tray from at least one of the tray cleaning liquid supply mechanism and the head cleaning liquid supply mechanism.

5. 5. The inkjet recording apparatus according to claim 4, wherein the head cleaning liquid supply mechanism supplies cleaning liquid between a movement start position of the blade and the nozzle surface.

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