Head unit, recording head, and inkjet recording device equipped therewith

Abstract

To provide a head unit which can suppress liquid leakage from a connection part at the time of replacement of a recording head with a simple configuration, a recording head, and an inkjet recording device having the same.SOLUTION: A head unit includes a common flow channel, one or more recording heads, and a joint mechanism. The joint mechanism has a first opening / closing valve for opening / closing a liquid supply path, and connects the common flow channel and the recording heads. The first opening / closing valve has a switching member having an insertion hole and an engagement boss projected on the inner peripheral surface of the insertion hole, a first opening / closing member having a sliding part which is inserted to the insertion hole so as to be vertically slidable and an engagement groove with which the engagement boss is engaged, and a first sealing member which is mounted on the first opening / closing member and comes into contact with or separates from the inner peripheral surface of the insertion hole. By rotating the switching member and vertically moving the first opening / closing member, the first opening / closing valve is switched between a close state where the first sealing member comes in contact with the inner peripheral surface of the insertion hole and an open state where the first sealing member separates from the inner peripheral surface of the insertion hole.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a head unit, a recording head, and an inkjet recording apparatus equipped with the same, which are mounted on an inkjet recording apparatus, and particularly relates to an attachment structure of the recording head to the head unit.

Background Art

[0002] Conventionally, in an inkjet recording apparatus such as an inkjet printer, ink is ejected from an ink ejection nozzle provided in a recording head, and the ejected ink adheres to a recording medium such as paper to form dots. In the inkjet recording apparatus as described above, it is conceivable that ink ejection becomes difficult at some ink ejection nozzles due to clogging or the like. In this case, it is necessary to replace the recording head.

[0003] In a so-called line head type printer in which the recording head is arranged such that the ink ejection nozzles are arranged over the entire width direction of the recording medium, for example, if three recording heads are unitized for each color, it is relatively easy to replace the entire head unit. This is because the liquid flow paths such as ink and cleaning liquid are completed in one head unit.

[0004] However, in most cases, only one recording head fails within the head unit. Therefore, replacing the entire head unit incurs an extra cost. Therefore, it is desirable to replace only the failed recording head. However, when replacing only one recording head, it is necessary to block the liquid flow path, and there is a concern about liquid leakage during replacement.

[0005] As a method to avoid ink leakage when replacing the recording head, for example, Patent Document 1 discloses an inkjet recording device in which a cartridge containing an ink tank is detachably held, and a negative pressure increasing mechanism is used to increase the negative pressure of the ink tank, and the increase in negative pressure by the negative pressure increasing mechanism is stopped when the printer is installed, thereby avoiding ink leakage during maintenance such as head replacement.

[0006] Furthermore, Patent Document 2 discloses an inkjet recording device in which an on-off valve for opening and closing an ink supply path is provided on a carriage on which a recording head is mounted, and by operating a head fixing lever, the on-off valve is opened using a lever attached to the head fixing lever when the recording head is coupled to the carriage, and the on-off valve is closed when the recording head is separated. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2002-36586 [Patent Document 2] Japanese Patent Publication No. 2006-68994 [Overview of the project] [Problems that the invention aims to solve]

[0008] The method described in Patent Document 1 requires a negative pressure increasing mechanism in the head cartridge, which complicates the configuration and increases costs. Furthermore, while the configuration in Patent Document 1 places the ink tank inside the head cartridge, it could not be applied to configurations where the ink tank is located separately from the recording head. Additionally, in the configuration of Patent Document 2, the supply valve is not opened or closed unless the head locking lever is operated, which creates a possibility of forgetting to operate the head locking lever or ink leakage during the time before the head locking lever is operated.

[0009] In view of the above problems, the present invention aims to provide a head unit, a recording head, and an inkjet recording apparatus equipped therewith that can suppress liquid leakage from the connecting portion when the recording head is replaced with a simple configuration. [Means for solving the problem]

[0010] To achieve the above objective, the first configuration of the present invention is a head unit mounted on an inkjet recording device that records an image on a recording medium, comprising a common channel, one or more recording heads, and a joint mechanism. The common channel has a liquid supply path through which one or more liquids, including ink, pass. The recording head is detachable from the common channel and has a plurality of nozzles for ejecting ink. The joint mechanism has a first on-off valve that opens and closes the liquid supply path and connects the liquid supply path and the recording head. The first on-off valve has a switching member, a first on-off member, and a first sealing member. The switching member has an insertion hole and an engagement boss protruding from the inner circumferential surface of the insertion hole. The first on-off member has a sliding portion that is inserted into the insertion hole so as to be slidable vertically, and an engagement groove formed so as to be inclined with respect to the axial direction of the sliding portion, into which the engagement boss engages. The first sealing member is mounted on the first on-off member and is in contact with or separated from the inner circumferential surface of the insertion hole. By rotating the switching member and moving the first opening / closing member up and down, the first opening / closing valve is switched between a closed state in which the first sealing member is in contact with the inner circumferential surface of the insertion hole, and an open state in which the first sealing member is separated from the inner circumferential surface of the insertion hole. [Effects of the Invention]

[0011] According to the first configuration of the present invention, by rotating the switching member of the first on-off valve to move the first on-off member up and down, it is possible to switch between a closed state in which the first sealing member attached to the first on-off member is in contact with the inner circumferential surface of the insertion hole of the switching member, and an open state in which it is separated from the inner circumferential surface of the insertion hole. Therefore, the liquid supply passage can be opened and closed with a simple configuration, and liquid leakage from the connecting portion when the recording head is replaced can also be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] Explanatory drawing showing a schematic configuration of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention [Figure 2] Plan view of a recording unit 9 provided in the printer 100 [Figure 3] Side view of recording heads 17a to 17c constituting line heads 11Y to 11K of the recording unit 9 [Figure 4] Plan view of recording heads 17a to 17c as viewed from the ink ejection surface F side [Figure 5] Schematic diagram showing an ink supply path 40a, a cleaning liquid supply path 40b, and an internal structure of recording heads 17a to 17c constituting the line head 11Y of the printer 100 [Figure 6] Side view of the head unit 51 as viewed from the upstream side in the paper conveyance direction [Figure 7] Plan view of the head unit 51 as viewed from above [Figure 8] Partial enlarged view of the vicinity of the recording head 17b of the head unit 51 [Figure 9] Side cross-sectional view of the joint mechanism 60a of the recording head 17b [Figure 10] Perspective view showing a state where the first on-off valve 61 is mounted on the common flow path 40 [Figure 11] Perspective view of a switching member 62 constituting the first on-off valve 61 [Figure 12] Perspective view of a first on-off member 63 constituting the first on-off valve 61 [Figure 13] Perspective view showing a state where a guide groove 63e of the first on-off member 63 is engaged with a rotation restricting rib 81 [Figure 14] Perspective view of a connecting member 65 [Figure 15] Side cross-sectional view of the joint mechanism 60a, showing a state where the first on-off valve 61 and the second on-off valve 67 are closed [Figure 16] Side cross-sectional view of the joint mechanism 60a, showing a state where the first on-off valve 61 and the second on-off valve 67 are open [Figure 17]An enlarged view of the vicinity of the joint mechanism 60a on the side surface of the recording head 17b, showing the state in which the joint mechanism 60a is connected [Figure 18] An enlarged view of the vicinity of the joint mechanism 60a on the side surface of the recording head 17b, showing the state in which the connecting member 65 is moved to the retracted position from the state of FIG. 17 [Figure 19] An enlarged perspective view of the gap portion between the first on-off valve 61 and the connecting member 65 in FIG. 18 [Figure 20] A schematic diagram showing the internal structure of the ink supply path 40a, the cleaning liquid supply path 40b, and the recording heads 117a to 117c constituting the line head 11Y of the printer 100 [Figure 21] A side cross-sectional view of the joint mechanism 160a in FIG. 20

Embodiments for Carrying Out the Invention

[0013] 〔1. Configuration of Inkjet Recording Apparatus〕 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention. The printer 100 includes a paper feed cassette 2 which is a paper storage unit. The paper feed cassette 2 is disposed below the inside of the printer main body 1. Inside the paper feed cassette 2, paper P which is an example of a recording medium is stored.

[0014] A paper feed device 3 is disposed on the downstream side in the paper conveyance direction of the paper feed cassette 2, that is, above the right side of the paper feed cassette 2 in FIG. 1. By this paper feed device 3, the paper P is sent out one by one while being separated toward the upper right of the paper feed cassette 2 in FIG. 1.

[0015] The printer 100 includes a first paper conveyance path 4a inside thereof. The first paper conveyance path 4a is located in the upper right direction which is its paper feed direction with respect to the paper feed cassette 2. The paper P sent out from the paper feed cassette 2 is conveyed vertically upward along the side surface of the printer main body 1 by the first paper conveyance path 4a.

[0016] In the paper transport direction, a pair of registration rollers 13 is provided at the downstream end of the first paper transport path 4a. Furthermore, the first transport unit 5 and the recording unit 9 are located immediately downstream of the pair of registration rollers 13 in the paper transport direction. Paper P fed from the paper cassette 2 travels through the first paper transport path 4a to reach the pair of registration rollers 13. The pair of registration rollers 13 corrects the diagonal feeding of the paper P and, in timing with the ink ejection operation performed by the recording unit 9, feeds the paper P toward the first transport unit 5 (particularly the first transport belt 8, which will be described later).

[0017] The paper P, fed to the first transport unit 5 by the registration roller pair 13, is transported by the first transport belt 8 to a position opposite the recording unit 9 (particularly the recording heads 17a to 17c, which will be described later). An image is recorded on the paper P by the ejection of ink from the recording unit 9 onto the paper P. At this time, the ejection of ink from the recording unit 9 is controlled by the control device 110 inside the printer 100.

[0018] In the paper transport direction, the second transport unit 12 is located downstream of the first transport unit 5 (left side in Figure 1). The paper P on which the image has been recorded by the recording unit 9 is sent to the second transport unit 12. The ink ejected onto the surface of the paper P dries as it passes through the second transport unit 12.

[0019] In the paper transport direction, a de-curler unit 14 is provided downstream of the second transport unit 12 and near the left side of the printer body 1. The paper P, whose ink has been dried by the second transport unit 12, is sent to the de-curler unit 14 to correct any curl that has formed on the paper P.

[0020] In the paper transport direction, a second paper transport path 4b is provided downstream of the decurler unit 14 (upper part of Figure 1). When double-sided recording is not performed, the paper P that has passed through the decurler unit 14 passes through the second paper transport path 4b and is discharged into a paper output tray 15a located on the left side outside the printer 100. Below the paper output tray 15a, a sub-output tray 15b is provided for discharging unwanted paper P (waste paper) that has printing defects or other issues.

[0021] An inversion transport path 16 for double-sided recording is provided at the top of the printer body 1, above the recording unit 9 and the second transport unit 12. When double-sided recording is performed, after recording on one side (first side) of the paper P is completed and the paper P has passed through the second transport unit 12 and the decurler unit 14, it is sent to the inversion transport path 16 via the second paper transport path 4b.

[0022] The paper P, sent to the reversal transport path 16, has its transport direction switched to record on the other side (second side) of the paper P. The paper P then passes over the top of the printer body 1 and is sent to the right, passing through the registration roller pair 13, and is sent back to the first transport unit 5 with the second side facing upwards. In the first transport unit 5, the paper P is transported to a position opposite the recording unit 9, and an image is recorded on the second side by ink ejection from the recording unit 9. After double-sided recording, the paper P passes through the second transport unit 12, the decurler unit 14, and the second paper transport path 4b in order and is discharged into the paper output tray 15a.

[0023] Furthermore, a maintenance unit 19 and a cap unit 20 are positioned below the second transport unit 12. The maintenance unit 19 moves horizontally below the recording unit 9 when purging is performed, wipes off the ink ejected from the ink outlet of the recording head, and recovers the wiped-off ink. Purging refers to the operation of forcibly pushing ink out from the ink outlet of the recording head in order to discharge thickened ink, foreign matter, and air bubbles from inside the ink outlet. The cap unit 20 moves horizontally below the recording unit 9 when capping the ink ejection surface of the recording head, and then moves upward to be attached to the bottom surface of the recording head.

[0024] Figure 2 is a plan view of the recording unit 9. The recording unit 9 comprises a head housing 10 and line heads 11Y, 11M, 11C, and 11K. The line heads 11Y to 11K are held in the head housing 10 at a height that forms a predetermined gap (e.g., 1 mm) with respect to the conveying surface of an endless first conveyor belt 8 stretched over a plurality of rollers, including a drive roller 6a, a driven roller 6b, and a tension roller (not shown). The drive roller 6a causes the first conveyor belt 8 to travel in the direction of conveying the paper P (direction of arrow A).

[0025] Each line head 11Y to 11K has multiple (in this case, three) recording heads 17a to 17c. The recording heads 17a to 17c are arranged in a staggered pattern along the paper width direction (arrow BB' direction) perpendicular to the paper transport direction (arrow A direction). Each recording head 17a to 17c has multiple ink nozzles 18. Each ink nozzle 18 is arranged at equal intervals in the width direction of the recording head, that is, in the paper width direction (arrow BB' direction). From the line heads 11Y to 11K, yellow (Y), magenta (M), cyan (C), and black (K) inks are ejected towards the paper P being transported by the first transport belt 8 via the ink nozzles 18 of the recording heads 17a to 17c.

[0026] Figure 3 is a side view of the recording heads 17a to 17c that constitute the line heads 11Y to 11K of the recording unit 9, and Figure 4 is a plan view of the recording heads 17a to 17c viewed from the ink ejection surface F1 side. Note that the recording heads 17a to 17c have the same shape and configuration, so they are shown in a single figure in Figures 3 and 4. As shown in Figures 3 and 4, the ink ejection surface (nozzle surface) F1 of the recording heads 17a to 17c is provided with multiple nozzle regions Ra to Rd (four blocks in this case) in which numerous ink ejection ports 18 (see Figure 2) are arranged. The ink ejection surface F1 is formed of, for example, SUS (stainless steel).

[0027] Each of the recording heads 17a to 17c, which make up each line head 11C to 11K, is supplied with four colors (cyan, magenta, yellow, and black) of ink from the liquid supply mechanism 50 (see Figure 5), according to the color of each line head 11C to 11K.

[0028] Each recording head 17a to 17c, in response to a control signal from the control device 110 (see Figure 1), ejects ink from its ink ejection port 18 toward the paper P being transported by being held and adsorbed onto the transport surface of the first transport belt 8, according to the image data received from an external computer. As a result, a color image is formed on the paper P on the first transport belt 8 by superimposing four colors of ink: cyan, magenta, yellow, and black. In addition, a cleaning fluid supply unit 30 for supplying cleaning fluid is provided at one end of the recording heads 17a to 17c in the longitudinal direction (arrow BB' direction), which is perpendicular to the paper transport direction (arrow A direction). The cleaning fluid supply unit 30 has a number of cleaning fluid supply ports 30a.

[0029] In printer 100, in order to clean the ink ejection surface F1 of the recording heads 17a to 17c, when starting printing after a long period of inactivity and between printing operations, ink is ejected (purged) from the ink ejection ports 18 of all recording heads 17a to 17c, and cleaning fluid is supplied from the cleaning fluid supply port 30a to the cleaning fluid supply surface F2. A wiper (not shown) then wipes the ink ejected onto the ink ejection surface F1 along with the cleaning fluid, performing a recovery operation of the recording heads 17a to 17c to prepare for the next printing operation. The ink and cleaning fluid wiped from the ink ejection surface F1 are collected by an ink receiving unit (not shown).

[0030] Figure 5 is a schematic diagram showing the internal structure of the ink supply path 40a, the cleaning fluid supply path 40b, and the recording heads 17a to 17c that constitute the line head 11Y of the printer 100. Note that the line heads 11M to 11K have exactly the same configuration, so their explanation is omitted. Also, since the internal structure of the recording heads 17a to 17c is identical, only the internal structure of recording head 17a is shown in Figure 5.

[0031] As shown in Figure 5, a common channel 40 through which ink and cleaning fluid pass is connected to the recording heads 17a to 17c. Within the common channel 40, two ink supply channels 40a through which ink passes and one cleaning fluid supply channel 40b through which cleaning fluid passes are formed. The upstream ends of the ink supply channels 40a and the cleaning fluid supply channel 40b are connected to a fluid supply mechanism 50. The fluid supply mechanism 50 consists of a tank for storing ink and cleaning fluid, and a pump (neither shown) for drawing ink and cleaning fluid from the tank.

[0032] The two ink supply paths 40a branch into six paths of three at the downstream end, and two of these are connected to the ink ejection ports 18 of the recording heads 17a to 17c. The cleaning fluid supply path 40b branches into three paths at the downstream end and is connected to the cleaning fluid supply section 30 (see Figures 3 and 4) of the recording heads 17a to 17c. The unit including the recording heads 17a to 17c and the common flow path 40 will be referred to as the head unit 51 (see Figure 6) below.

[0033] Each recording head 17a to 17c has a front head portion 41, a back head portion 43, and a heater 44. The front head portion 41 is provided with an ink ejection surface F1 on which numerous ink ejection ports 18 are arranged, and a cleaning fluid supply section 30 for supplying cleaning fluid (see Figure 4 for both).

[0034] The back of the print head 43 includes an ink heating channel 45, a filter 46, a reservoir tank 47, and a damper 48. The ink supply channel 40a passes sequentially through the ink heating channel 45, the filter 46, the reservoir tank 47, and the damper 48 before being connected to the ink ejection port 18 on the front of the print head 41.

[0035] A heater 44 is positioned between the front of the print head 41 and the back of the print head 43. The heater 44 heats the ink in the ink heating channel 45 (described later) to a predetermined temperature as needed, and also heats the front of the print head 41 so that ink can be smoothly ejected from the ink ejection port 18.

[0036] The ink heating channel 45 heats the ink in the ink supply channel 40a to a predetermined temperature. The ink heating channel 45 is located in the back of the print head 43, adjacent to the heater 49. The filter 46 removes foreign matter from the ink passing through the ink supply channel 40a. The reservoir tank 47 temporarily stores the ink passing through the ink supply channel 40a. The damper 48 is made of a flexible resin film and pushes the ink out to the front of the print head 41 by pulsating the damper 48.

[0037] One of the two ink supply paths 40a is used to supply ink from the liquid supply mechanism 50 to the recording heads 17a to 17c, and the other is used to collect ink from the recording heads 17a to 17c and return it to the liquid supply mechanism 50. When recording images with a large ink output, both of the two ink supply paths 40a can also be used to supply ink to the recording heads 17a to 17c.

[0038] Figure 6 is a side view of the head unit 51 as seen from the upstream side (right side in Figure 2) in the paper transport direction. Figure 7 is a top view of the head unit 51 as seen from above. Figure 8 is a magnified view of the area around the recording head 17b of the head unit 51. The recording heads 17a to 17c are each individually detachable from the common channel 40. More specifically, three joint mechanisms 60a to 60c that connect each recording head 17a to 17c to the common channel 40 are fastened from above the common channel 40 by three first fixing screws 55 at each joint (a total of nine screws). In addition, both the left and right ends of each recording head 17a to 17c are fastened to the common channel 40 by second fixing screws 57. Heat sinks 53 are attached to the sides of each recording head 17a to 17c. The heat sinks 53 release heat generated from a flexible circuit board (not shown) located inside.

[0039] Joint mechanisms 60a and 60b are each connected to two ink supply passages 40a (see Figure 7). Joint mechanism 60c is connected to cleaning fluid supply passage 40b.

[0040] [2. Configuration of the joint mechanism] The detailed configurations of the joint mechanisms 60a to 60c will be described below. Figure 9 is a side cross-sectional view of the joint mechanism 60a of the recording head 17b. Figure 10 is a perspective view showing the first on-off valve 61 mounted in the common flow path 40. Figure 11 is a perspective view of the switching member 62 constituting the first on-off valve 61. Figure 12 is a perspective view of the first on-off member 63 constituting the first on-off valve 61. Figure 13 is a perspective view showing the guide groove 63e of the first on-off member 63 engaged with the rotation restricting rib 81. Figure 14 is a perspective view of the connecting member 65. Here, the configuration of the joint mechanism 60a of the recording head 17b is used as an example, but the joint mechanisms 60b and 60c have the same configuration as the joint mechanism 60a. Also, the joint mechanisms 60a to 60c of the recording heads 17a and 17c have the same configuration.

[0041] As shown in Figure 9, the joint mechanism 60a comprises a first on-off valve 61, a connecting member 65, and a second on-off valve 67. The first on-off valve 61 is installed at the end of the ink supply passage 40a and the cleaning fluid supply passage 40b (see Figure 7) of the common flow path 40. The first on-off valve 61 has a switching member 62 and a first on-off member 63.

[0042] As shown in Figure 11, the switching member 62 is a hollow, substantially cylindrical shape with a diameter that gradually decreases upwards, and has an insertion hole 62a into which the first opening / closing member 63 is inserted. An engagement boss 62b is provided protruding from the inner circumferential surface of the insertion hole 62a. A first flange portion 62c, a second flange portion 62d, and a lever portion 62e are formed on the outer circumferential surface of the switching member 62. A first O-ring 80a (see Figure 9) is fitted to the first flange portion 62c to seal the gap between the common flow path 40 and the switching member 62. A second O-ring 80b (see Figure 9) is fitted to the second flange portion 62d to seal the gap between the first opening / closing valve 61 and the connecting member 65. The lever portion 62e is pressed in the circumferential direction when the switching member 62 is rotated to open and close the first opening / closing valve 61.

[0043] An engaging claw 62f is formed at the upper end of the switching member 62. The engaging claw 62f engages with the engaged portion 40c (see Figure 9) in the common flow path 40, thereby preventing the switching member 62 from falling when the recording heads 17a to 17c are removed, as shown in Figure 10.

[0044] As shown in Figure 12, the first opening / closing member 63 has a sliding portion 63a, a pressing portion 63b, and a small-diameter portion 63c. The sliding portion 63a is substantially cylindrical and is inserted into the insertion hole 62a of the switching member 62 so as to be slidable in the vertical direction. An engagement groove 63d and a guide groove 63e are formed on the outer surface of the sliding portion 63a. The engagement groove 63d is formed to be inclined with respect to the axial direction (vertical direction) of the sliding portion 63a, and the engagement boss 62b of the switching member 62 (see Figure 11) engages with it. The guide groove 63e is formed parallel to the axial direction (vertical direction) at a position opposite to the engagement groove 63d of the sliding portion 63a.

[0045] Figure 13 is a perspective view showing the state in which the guide groove 63e of the first opening / closing member 63 is engaged with the rotation restricting rib 81. The rotation restricting rib 81 is provided protruding from the lower surface of the common flow path 40 (see Figure 10), and with the first opening / closing valve 61 attached to the common flow path 40, the guide groove 63e of the first opening / closing member 63 engages with the rotation restricting rib 81 as shown in Figure 13.

[0046] The pressing portion 63b is provided at the lower end of the first opening / closing member 63 and contacts the tip portion 68a (see Figure 15) of the second opening / closing member 68. The small diameter portion 63c is formed between the sliding portion 63a and the pressing portion 63b and is fitted with a third O-ring 80c (see Figure 9, first sealing member) which contacts the inner surface of the insertion hole 62a of the switching member 62 when the first opening / closing valve 61 is closed.

[0047] As shown in Figure 14, the connecting member 65 has a hollow cylindrical main body 65a with open upper and lower ends, and a support plate 65b fixed horizontally in a direction perpendicular to the axial direction near the upper end of the main body 65a. The upper end of the main body 65a is connected to the first on / off valve 61 (see Figure 9). The lower end of the main body 65a is connected to the ink supply port 70 of the recording head 17b (see Figure 9).

[0048] A liquid passage port 65c is formed near the upper end of the main body portion 65a. A second on-off valve 67 (see Figure 9) is positioned inside the main body portion 65a. The second on-off valve 67 includes a second on-off member 68 and a coil spring 69 that biases the second on-off member 68 upward. The liquid passage port 65c has a smaller inner diameter than other parts of the main body portion 65a, and the biasing force of the coil spring 69 presses the second on-off member 68 against it, thereby closing the ink flow path within the connecting member 65. A fourth O-ring 80d (see Figure 9, second sealing member) is fitted to the second on-off member 68 and contacts the periphery of the liquid passage port 65c.

[0049] The tip 68a of the second opening / closing member 68 protrudes upward from the liquid passage 65c of the connecting member 65 and contacts the pressing portion 63b of the first opening / closing member 63. The lower end of the coil spring 69 is fixed to a spring receiving portion 70a formed in the ink supply port 70 of the recording head 17b. A fifth O-ring 80e (see Figure 9) is fitted to the ink supply port 70 to seal the gap between the connecting member 65 and the ink supply port 70.

[0050] Three screw holes 65d are formed on the upper surface of the main body 65a, into which the first fixing screws 55 are fastened. By fastening the first fixing screws 55 into the screw holes 65d, the connecting member 65 is fixed in the position (connecting position) where it is connected to the first on-off valve 61, as shown in Figure 9.

[0051] A liquid reservoir 73 is formed between the upper surface of the main body 65a and the liquid passage 65c. As shown in Figure 9, the liquid reservoir 73 has a larger diameter than the portion below the liquid passage 65c and has a volume equal to or greater than the space between the first on-off valve 61 and the second on-off valve 67. A projection 71 is formed on the side end of the support plate 65b. The projection 71 protrudes outward from the opening 53a (see Figure 17) formed in the heat sink 53.

[0052] Next, the opening and closing operations of the first on-off valve 61 and the second on-off valve 67 will be described. Figures 15 and 16 are side cross-sectional views of the joint mechanism 60a, showing the first on-off valve 61 and the second on-off valve 67 in a closed state and an open state, respectively.

[0053] In the state shown in Figure 15, the engagement boss 62b of the switching member 62 is located at the lower end of the engagement groove 63d of the first opening / closing member 63, and the third O-ring 80c attached to the first opening / closing member 63 is pressed against the inner wall surface of the insertion hole 62a of the switching member 62, so that the first opening / closing valve 61 is in the closed state.

[0054] Furthermore, in the state shown in Figure 15, where the first on-off valve 61 is closed, the second on-off member 68 is pushed upward by the biasing force of the coil spring 69. As a result, the fourth O-ring 80d attached to the second on-off member 68 is pressed against the periphery of the fluid passage port 65c, causing the second on-off valve 67 to be closed.

[0055] To open the first on-off valve 61, from the state shown in Figure 15, the lever portion 62e of the switching member 62 is pressed circumferentially with the tip of a screwdriver or the like to rotate the switching member 62 in a predetermined direction (clockwise in Figure 11). Here, the rotation of the first on-off member 63 is restricted by the engagement of the guide groove 63e and the rotation restricting rib 81. As a result, the engagement boss 62b of the switching member 62 moves from the lower end to the upper end within the engagement groove 63d of the first on-off member 63. Since the switching member 62 is fixed to the common flow path 40, the movement of the engagement boss 62b causes the first on-off member 63 to move downward. As a result, as shown in Figure 16, the third O-ring 80c attached to the first on-off member 63 separates from the inner wall surface of the insertion hole 62a of the switching member 62, and the first on-off valve 61 opens. The first opening / closing member 63 moves smoothly downward along the rotation restricting rib 81 due to the sliding motion between the guide groove 63e and the rotation restricting rib 81. In other words, the rotation restricting rib 81 also functions as a guide rib when the first opening / closing member 63 moves in the vertical direction.

[0056] Furthermore, as the first opening / closing member 63 moves downward, the second opening / closing member 68, which is in contact with the pressing portion 63b of the first opening / closing member 63, is pressed downward. As a result, the second opening / closing member 68 moves downward against the biasing force of the coil spring 69. Consequently, as shown in Figure 16, the fourth O-ring 80d attached to the second opening / closing member 68 moves away from the periphery of the liquid passage port 65c of the connecting member 65, and the second opening / closing valve 67 also opens.

[0057] With the above configuration, the second on-off valve 67 located on the connecting member 65 side (recording heads 17a-17c side) opens and closes in accordance with the opening and closing operation of the first on-off valve 61 located on the common flow path 40 side. In other words, the first on-off valve 61 located on the common flow path 40 side and the second on-off valve 67 located on the connecting member 65 side (recording heads 17a-17c side) can be opened and closed simultaneously with a single operation. Therefore, the risk of forgetting to close the first on-off valve 61 or the second on-off valve 67 when removing the recording heads 17a-17c from the head unit 51, or forgetting to open the first on-off valve 61 or the second on-off valve 67 when mounting the recording heads 17a-17c to the head unit 51, is reduced.

[0058] Therefore, ink leakage and cleaning fluid leakage caused by replacing the recording heads 17a to 17c without closing the first on / off valve 61 or the second on / off valve 67 can be suppressed. In addition, printing problems caused by forgetting to open the first on / off valve 61 or the second on / off valve 67 after replacing the recording heads 17a to 17c can also be suppressed.

[0059] Here, when the first on-off valve 61 and the second on-off valve 67 are closed, ink or cleaning fluid remains in the space between the first on-off valve 61 and the second on-off valve 67 (the space from the insertion hole 62a of the switching member 62 to the liquid passage 65c of the connecting member 65). Therefore, even if the recording heads 17a to 17c are removed from the common flow path 40 with the first on-off valve 61 and the second on-off valve 67 closed, there is a risk that the ink or cleaning fluid remaining between the first on-off valve 61 and the second on-off valve 67 may leak out.

[0060] Therefore, in this embodiment, a liquid reservoir 73 is formed on the upper surface of the connecting member 65 that constitutes the joint mechanism 60a to 60c, having a volume equal to or greater than the space between the first on-off valve 61 and the second on-off valve 67. As a result, when the recording heads 17a to 17c are removed from the common flow path 40, any ink or cleaning fluid remaining between the first on-off valve 61 and the second on-off valve 67 is stored in the liquid reservoir 73, thereby suppressing contamination of the printer 100 due to leakage of ink or cleaning fluid.

[0061] [3. Procedure for attaching and detaching the recording head] Next, we will explain the procedure for attaching and detaching the recording heads 17a to 17c. Figure 17 is a magnified view of the area around the joint mechanism 60a on the side of the recording head 17b. Here, we will explain the procedure for attaching and detaching the recording head 17b, but the procedure is the same for recording heads 17a and 17c.

[0062] To remove the recording head 17b from the common flow path 40, first, the lever portion 62e of the switching member 62 is operated to close the first on-off valve 61 and the second on-off valve 67 as shown in Figure 15. Next, the nine first fixing screws 55, three of which are fastened to each of the three joint mechanisms 60a to 60c, are removed. By removing the first fixing screws 55, the fastening between the connecting member 65 and the common flow path 40 is released, and the connecting member 65 is held in the connected position solely by the biasing force of the coil spring 69. The recording head 17b is fastened to the common flow path 40 by the second fixing screw 57.

[0063] Next, the projection 71 of the support plate 65b that protrudes from the opening 53a of the heat sink 53 is pressed down with a finger. As a result, the main body 65a to which the support plate 65b is fixed is also pressed down together with the support plate 65b against the biasing force of the coil spring 69. That is, the connecting member 65 moves to a position where it has retracted downward from the connecting position (retracted position).

[0064] Figure 18 shows the state after moving the connecting member 65 to the retracted position from the state shown in Figure 17. Figure 19 is an enlarged perspective view of the gap between the first on-off valve 61 and the connecting member 65 in Figure 18. As shown in Figures 18 and 19, a gap D is formed between the first on-off valve 61 and the connecting member 65 as the connecting member 65 moves to the retracted position.

[0065] By inserting paper or cloth into this gap D, any ink or cleaning fluid remaining between the first on / off valve 61 and the connecting member 65 can be absorbed. Any ink or cleaning fluid that cannot be absorbed by the paper or cloth is stored in the liquid reservoir 73. After that, the second fixing screws 57 fastened to the left and right sides of the recording head 17b are removed, and the recording head 17b is removed from the common flow path 40.

[0066] When attaching the recording head 17b to the common flow path 40, the first on-off valves 61 of the three joint mechanisms 60a to 60c are closed, and the connecting members 65 are connected to the first on-off valves 61 of each. Then, the first fixing screws 55 and the second fixing screws 57 are fastened to attach the recording head 17b to the common flow path 40. After that, the lever portion 62e of the switching member 62 of each joint mechanism 60a to 60c is operated to open the first on-off valves 61 and the second on-off valves 67, enabling the supply of ink and cleaning fluid to the recording head 17b.

[0067] Furthermore, when the first on-off valve 61 and the second on-off valve 67 are in the closed position, the lever portion 62e of the switching member 62 overlaps with the fastening path of the first fixing screw 55. Therefore, in order to fasten the first fixing screw 55, it is necessary to operate the lever portion 62e to open the first on-off valve 61 and the second on-off valve 67. In other words, the connecting member 65 cannot be installed unless the first on-off valve 61 and the second on-off valve 67 are in the open position, thus ensuring that the first on-off valve 61 and the second on-off valve 67 are in the open position when installing the connecting member 65.

[0068] By attaching and detaching the recording heads 17a to 17c using the procedure described above, leakage of ink and cleaning fluid from the joint mechanisms 60a to 60c can be effectively suppressed with a simple configuration and operation.

[0069] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, although the above embodiment described a configuration in which three recording heads 17a to 17c are mounted on one head unit 51, the head unit 51 may also be configured to have only one recording head, or to have two or four or more recording heads.

[0070] Furthermore, in the above embodiment, each recording head 17a to 17c is equipped with joint mechanisms 60a and 60b for ink supply and a joint mechanism 60c for cleaning fluid supply, but the number and arrangement of the joint mechanisms can be appropriately changed depending on the configuration of the recording head, etc.

[0071] Furthermore, although the above embodiment described an example using a color printer that records color images using four colors of ink as the inkjet recording device, it is also possible to use the ink discharge path of this embodiment even when using a monochrome printer that records monochrome images using black ink.

[0072] Figure 20 is a schematic diagram showing another example of the internal structure of the ink supply path 40a, the cleaning fluid supply path 40b, and the recording heads 117a to 117c that constitute the line head 11Y of the printer 100. Note that parts common to the configuration in Figure 5 are omitted from the explanation.

[0073] Each recording head 117a to 117c has a front head portion 41, a back head portion 43, a heater 44, and a joint mechanism 160a. The joint mechanism 160a connects the front head portion 41 and the back head portion 43. The joint mechanism 160a has an ink supply passage 40a and a cleaning fluid supply passage 40b through which ink and cleaning fluid flow. The joint mechanism 160a is provided at both ends in the longitudinal direction of each recording head 117a to 117c.

[0074] Figure 21 is a side cross-sectional view of the joint mechanism 160a in Figure 20. Figure 21 shows the structure of the left-side joint mechanism 160a in Figure 20, which connects the ink supply passage 40a of the back of the head 43 to the front of the head 41. The right-side joint mechanism 160a in Figure 20 has basically the same configuration as in Figure 21, but it is equipped with two first on-off valves 61 to connect the ink supply passage 40a and the cleaning fluid supply passage 40b.

[0075] As shown in Figure 21, the joint structure 160a is configured such that one end of the first on-off valve 61 is connected to the opening 43a of the back of the print head 43 and is attached to the end of the ink supply passage 40a of the common flow path 40. Specifically, the switching member 62 of the first on-off valve 61 is provided on the opening 43a of the back of the print head 43. The first on-off member 63 of the first on-off valve 61 is provided on the opening 43a of the back of the print head 41 to open and close the ink supply passage 40a. The other end of the first on-off valve 61 is connected to a connecting member 65 attached to the opening 41a of the front of the print head 41. An ink reservoir 73 is formed at the upper end of the connecting member 65.

[0076] As described above, in this embodiment, the recording heads 117a to 117b are joined together by a joint mechanism 160a, with the front head portion 41 and the back head portion 43 connected. Therefore, when replacing the recording heads 117a to 117b by removing the front head portion 41 and the back head portion 43, leakage of liquid from the connecting portion can be suppressed.

[0077] Furthermore, although an example of joining the head front portion 41 and the head back portion 43 by a joint mechanism 160a has been shown, the invention is not limited to this. For example, the head front portion 41 and the head back portion 43 may be joined by a joint mechanism 60a. In this case as well, when removing the head front portion 41 and the head back portion 43 to replace the recording heads 117a to 117b, leakage of liquid from the connecting portion can be suppressed. [Industrial applicability]

[0078] This invention can be used in inkjet recording devices such as inkjet printers equipped with a detachable recording head. [Explanation of symbols]

[0079] 17a~17c, 117a~117c recording head 18. Ink nozzle 30 Cleaning fluid supply unit 40 Common channel 40a Ink supply path (liquid supply path) 40b Cleaning fluid supply path (fluid supply path) 50 Liquid supply mechanism 51 Head Unit 60a~60c, 160a Joint mechanism 61. First shut-off valve 62 Switching member 62a Insertion hole 62b Engaging Boss 62e Lever section 62f Engaging claw 63 First opening / closing member 63d Engagement groove 63e Guide groove 65 Connecting member 67 Second shut-off valve 68 Second opening / closing member 69. Coil spring (biasing member) 70 Ink supply port (liquid supply port) 71 Protrusion 73 Liquid storage section 81 Rotation regulating rib 100 Printers (Inkjet Recording Devices)

Claims

1. A common channel having a liquid supply path through which one or more liquids, including ink, pass, One or more recording heads that are detachable from the common flow path and have multiple nozzles for ejecting the ink, A joint mechanism that connects the liquid supply passage to the liquid supply port of the recording head and has a first on / off valve for opening and closing the liquid supply passage, A head unit equipped with and mounted on an inkjet recording device for recording images on a recording medium, The first on-off valve is, A switching member having an insertion hole and an engaging boss protruding from the inner circumferential surface of the insertion hole, A first opening / closing member having a sliding portion that is inserted into the insertion hole so as to be slidable vertically, and an engagement groove formed so as to be inclined with respect to the axial direction of the sliding portion, into which the engagement boss engages, The first sealing member is attached to the first opening / closing member and is in contact with or separated from the inner circumferential surface of the insertion hole, A head unit characterized in that the first on / off valve is switched between a closed state in which the first sealing member is in contact with the inner circumferential surface of the insertion hole and an open state in which the first sealing member is separated from the inner circumferential surface of the insertion hole by rotating the switching member to move the first on / off member up and down.

2. The aforementioned joint mechanism is A connecting member that connects the first on / off valve and the liquid supply port, A second on / off valve is provided inside the aforementioned connecting member, The head unit according to claim 1, wherein the second on-off valve opens and closes in accordance with the opening and closing operation of the first on-off valve.

3. The second shut-off valve is, A second opening / closing member protrudes from the liquid passage of the connecting member and contacts the first opening / closing member, A biasing member that biases the second opening / closing member toward the first opening / closing member, The device includes a second sealing member which is attached to the second opening / closing member and which contacts or separates from the peripheral edge of the liquid passage opening, The head unit according to claim 2, characterized in that the second on-off valve is switched between a closed state in which the second sealing member is in contact with the peripheral edge of the liquid passage port and an open state in which the second sealing member is separated from the peripheral edge of the liquid passage port by rotating the switching member to move the first on-off member up and down.

4. The switching member has a lever portion that is operated when the switching member is rotated, The head unit according to claim 2 or 3, characterized in that the lever portion restricts the screw fixing of the connecting member to the common flow path when the first on-off valve is in the closed state, and allows the screw fixing of the connecting member to the common flow path when the first on-off valve is in the open state.

5. The head unit according to any one of claims 1 to 4, characterized in that the first on-off valve has a guide groove into which a rotation-restricting rib protruding from the common flow path is inserted, and the rotation of the first on-off valve is restricted when the switching member is rotated by contact between the rotation-restricting rib and the inner wall surface of the guide groove.

6. The head unit according to claim 5, wherein the guide groove is formed parallel to the axial direction of the sliding portion, and the first opening / closing member moves vertically along the rotation restricting rib by sliding between the rotation restricting rib and the inner wall surface of the guide groove.

7. The head unit according to any one of claims 1 to 6, characterized in that the switching member has an engaging claw that engages with the engaged portion in the common flow path.

8. A head unit according to any one of claims 1 to 7, A liquid supply mechanism that supplies the liquid to the head unit, An inkjet recording device equipped with [a specific feature].

9. The front part of the head has multiple nozzles, The head rear section has a liquid supply passage through which one or more liquids, including ink, pass, and supplies liquid to the front of the head, A joint mechanism having a first on / off valve that connects the front part of the head and the back part of the head and opens and closes the liquid supply passage, A recording head mounted on an inkjet recording device for recording images on a recording medium, comprising: The first on-off valve is, A switching member having an insertion hole and an engaging boss protruding from the inner circumferential surface of the insertion hole, A first opening / closing member having a sliding portion that is inserted into the insertion hole so as to be slidable vertically, and an engagement groove formed so as to be inclined with respect to the axial direction of the sliding portion, into which the engagement boss engages, A first sealing member is attached to the first opening / closing member and is in contact with or separated from the inner circumferential surface of the insertion hole, It has, A recording head characterized in that the first on / off valve is switched between a closed state in which the first sealing member is in contact with the inner circumferential surface of the insertion hole and an open state in which the first sealing member is separated from the inner circumferential surface of the insertion hole by rotating the switching member and moving the first on / off member up and down.

10. The recording head described in claim 9, A common channel having the aforementioned liquid supply path, A head unit equipped with this feature.

11. The head unit according to claim 10, A liquid supply mechanism that supplies the liquid to the head unit, An inkjet recording device equipped with [a specific feature].

Images