Liquid ejection apparatus and inkjet recording apparatus

Abstract

To provide a liquid jet device capable of cooling a control board of a liquid jet head without cooling a liquid supply passage.SOLUTION: In a liquid jet device 50, a liquid jet head 51 includes a liquid jet part 511, a control board 513, and a head housing 514. The liquid jet part 511 jets ink on a sheet. The control board 513 controls the movement of the liquid jet part 511. The head housing 514 covers the control board 513 and accommodates it inside. A liquid supply passage 52 supplies ink to the liquid jet head 51. A body housing 54 covers a part of the liquid jet head 51 excluding the liquid jet part 511, and accommodates it inside. A fan causes air to circulate between the body housing 54 and the head housing 514. The liquid supply passage 52 is inserted from the outside into the inside of the body housing 54 in the vicinity of the liquid jet head 51, and is connected to the liquid jet head 51.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a liquid ejecting apparatus and an inkjet recording apparatus. [Background technology]

[0002] A liquid ejection device mounted on an inkjet recording device has a liquid ejection head that ejects ink (liquid) onto a recording medium such as paper. The liquid ejection head may include a control board that controls operations related to the ejection of liquid. In order to obtain a predetermined performance in the liquid ejection head, the control board needs to be cooled.

[0003] For example, the conventional inkjet device disclosed in Patent Document 1 includes a circuit board having a drive circuit for driving a head, a heat sink for dissipating heat generated by the circuit board, and a fan for generating an airflow capable of cooling the heat sink. This allows the heat generated by the drive circuit to be dissipated via the heat sink. Furthermore, the heat sink can be cooled by the fan, which improves the cooling effect of the circuit board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-198926 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when it comes to ink (liquid), a drop in temperature increases the viscosity, causing a large pressure loss in the supply path. This can lead to a decrease in the amount of ink ejected. In other words, although the control board needs to be cooled, there is a problem in that the amount of ink ejected decreases if the ink supply path is also cooled at the same time.

[0006] The present invention has been made in consideration of the above-mentioned points, and aims to provide a liquid ejection device and an inkjet recording device that are capable of cooling the control board of the liquid ejection head without cooling the liquid supply path. [Means for solving the problem]

[0007] In order to solve the above problems, the liquid ejection device of the present invention includes a liquid ejection head, a liquid supply path, a main body housing, and a fan. The liquid ejection head includes a liquid ejection unit, a control board, and a head housing. The liquid ejection unit ejects liquid onto a recording medium. The control board controls the operation of the liquid ejection unit. The head housing covers the control board and houses it therein. The liquid supply path supplies liquid to the liquid ejection head. The main body housing covers a portion of the liquid ejection head excluding the liquid ejection unit and houses it therein. The fan circulates air between the main body housing and the head housing. The liquid supply path is inserted from the outside of the main body housing into the inside near the liquid ejection head and is connected to the liquid ejection head. Effect of the Invention

[0008] According to the configuration of the present invention, most of the liquid supply path is disposed outside the main body housing, except for the vicinity of the connection point with the liquid jet head. This makes it possible to prevent the liquid supply path from contacting the air flow generated by the operation of the fan as much as possible. Therefore, it is possible to cool the control board of the liquid jet head without cooling the liquid supply path. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of a recording unit of the inkjet recording apparatus of FIG. [Diagram 3] FIG. 2 is a schematic diagram showing the periphery of a recording unit of the inkjet recording apparatus of FIG. [Figure 4] 4 is a perspective view of the liquid ejecting device of the recording unit of FIG. 3 as viewed from above. [Diagram 5] 4 is a perspective view of the liquid ejecting device of the recording unit in FIG. 3, as viewed from below. [Figure 6] 5 is a perspective view of the liquid ejecting device in FIG. 4 with a top cover removed. FIG. [Figure 7] 5 is a perspective view of the liquid ejecting device in FIG. 4 with a main body housing removed. FIG. [Figure 8] 8 is a vertical cross-sectional view of the liquid ejection head of the liquid ejection device of FIG. 7, as viewed from the paper transport direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following.

[0011] Fig. 1 is a cross-sectional view showing a schematic configuration of an inkjet recording apparatus 1 of an embodiment. Fig. 2 is a plan view of a recording unit 5 of the inkjet recording apparatus 1 of Fig. 1. Fig. 3 is a schematic configuration diagram showing the periphery of the recording unit 5 of the inkjet recording apparatus 1 of Fig. 1. The inkjet recording apparatus 1 is, for example, an inkjet recording printer. As shown in Figs. 1, 2 and 3, the inkjet recording apparatus 1 includes a paper supply unit 3, a paper transport unit 4, a recording unit 5, a drying unit 6 and an overall control unit 7.

[0012] The paper supply unit 3 stores a plurality of sheets of paper (recording medium) P, and separates and sends out the sheets of paper P one by one during recording. The paper transport unit 4 transports the sheets of paper P sent out from the paper supply unit 3 to the recording unit 5 and drying unit 6, and then discharges the sheets of paper P after recording and drying to the paper discharge unit 21. When double-sided recording is performed, the paper transport unit 4 distributes the sheets of paper P after recording and drying on the first side to the reversing transport unit 44 by the branching unit 43, and then switches the transport direction to reversing the sheets of paper P and transports them again to the recording unit 5 and drying unit 6.

[0013] The paper transport section 4 has a first belt transport section 41 and a second belt transport section 42. The first belt transport section 41 and the second belt transport section 42 adsorb and hold the paper P on the upper surface of an endless belt and transport it.

[0014] The recording unit 5 faces the paper P, which is attracted to and held on the upper surface of the first belt transport unit 41 and transported, and is disposed above the first belt transport unit 41 with a predetermined gap therebetween. The recording unit 5 has a liquid ejecting device 50 equipped with a line-type inkjet liquid ejecting head 51. As shown in FIG. 2, the liquid ejecting device 50 includes liquid ejecting devices 50B, 50C, 50M, and 50Y corresponding to four colors, black, cyan, magenta, and yellow, respectively. Similarly, the liquid ejecting head 51 includes liquid ejecting heads 51B, 51C, 51M, and 51Y corresponding to four colors, black, cyan, magenta, and yellow, respectively.

[0015] 3, the liquid ejection head 51 has a liquid ejection unit 511 at its bottom. The liquid ejection unit 511 is arranged along the paper width direction Dw, and can eject ink (liquid) over the entire recording area on the paper P. The recording unit 5 sequentially ejects ink from four color liquid ejection heads 51B, 51C, 51M, and 51Y toward the paper P transported by the first belt transport unit 41, and records a full-color image or a monochrome image on the paper P.

[0016] The drying unit 6 is disposed downstream of the recording unit 5 in the paper transport direction, and is provided with a second belt transport unit 42. The paper P on which an ink image has been recorded in the recording unit 5 is adsorbed and held by the second belt transport unit 42 in the drying unit 6, and while being transported, the ink is dried.

[0017] The overall control unit 7 includes a CPU, a storage unit, and other electronic circuits and electronic components, not shown. The CPU controls the operation of each component provided in the inkjet recording device 1 based on control programs and data stored in the storage unit to perform processing related to the functions of the inkjet recording device 1. The paper supply unit 3, the paper transport unit 4, the recording unit 5, and the drying unit 6 each receive commands individually from the overall control unit 7 and perform recording on the paper P in cooperation with each other. The storage unit is configured by a combination of a non-volatile storage device, such as a program ROM (Read Only Memory) or a data ROM, not shown, and a volatile storage device, such as a RAM (Random Access Memory).

[0018] Next, the configuration of the liquid ejection device 50 of the inkjet recording device 1 will be described with reference to FIGS. 2 and 3, as well as FIGS. 4, 5, 6, 7, and 8. FIG. 4 is a perspective view of the liquid ejection device 50 of the recording unit 5 of FIG. 3, seen from above. FIG. 5 is a perspective view of the liquid ejection device 50 of the recording unit 5 of FIG. 3, seen from below. FIG. 6 is a perspective view of the liquid ejection device 50 of FIG. 4, showing a state in which the upper cover 542 is removed. FIG. 7 is a perspective view of the liquid ejection device 50 of FIG. 4, showing a state in which the main body housing 54 is removed. FIG. 8 is a vertical cross-sectional view of the liquid ejection head 51 of the liquid ejection device 50 of FIG. 7, seen from the paper transport direction Dc. The outline arrow in FIG. 8 indicates the flow direction of the ink (liquid).

[0019] Since the liquid ejecting devices 50B, 50C, 50M, and 50Y of the four colors have the same shape and configuration, only one will be described as a representative example, and the identification symbols representing the respective colors will be omitted.

[0020] The liquid ejecting device 50 includes a liquid ejecting head 51 , a liquid supply path 52 , a cleaning liquid supply path 53 , a main body housing 54 , and a fan 55 .

[0021] 2, 6 and 7, a plurality of (for example, three) liquid ejection heads 51 are provided on the main body housing 54. The three liquid ejection heads 51 are arranged in a staggered manner, for example, along the paper width direction Dw perpendicular to the paper transport direction Dc.

[0022] As shown in FIGS. 5 and 8, the liquid ejecting head 51 includes a liquid ejecting unit 511, a common passage 512, a control board 513, and a head housing 514.

[0023] The liquid ejection unit 511 is disposed at the bottom of the liquid ejection head 51. The bottom surface of the liquid ejection unit 511 is an ink ejection surface 511a on which a plurality of ink ejection nozzles 5111 are open. The ink ejection surface 511a faces the paper P that is adsorbed and held on the upper surface of the first belt transport unit 41 and transported, and is parallel to the surface of the paper P. The liquid ejection unit 511 ejects ink (liquid) onto the paper P that is adsorbed and held on the upper surface of the first belt transport unit 41 and transported.

[0024] The liquid ejection unit 511 includes a plurality of ink ejection nozzles 5111 and drive elements (not shown) for the ink ejection nozzles 5111. The plurality of ink ejection nozzles 5111 are arranged in a line along the paper width direction Dw on the ink ejection surface 511a, and can eject (eject) ink over the entire recording area.

[0025] The common passage 512 is disposed above the liquid ejecting portion 511. The common passage 512 is an ink passage that extends parallel to the lower surface of the liquid ejecting portion 511. Both ends of the common passage 512 in the ink flow direction are connected to two liquid supply paths 52, and ink flows in through the common passage 512. The common passage 512 is connected to the upstream end of the ink ejecting nozzle 5111 in the ink flow direction, and supplies ink to the ink ejecting nozzle 5111.

[0026] The control board 513 is disposed above the common passage 512. The control board 513 controls the operation of the liquid ejection unit 511. In detail, the control board 513 controls the drive elements of the liquid ejection unit 511, and controls the ink ejection operation from the ink ejection nozzles 5111. The control board 513 receives control commands related to the ink ejection operation from the overall control unit 7.

[0027] The head housing 514 has, for example, a rectangular parallelepiped box shape, and covers and houses the common passage 512 and the control board 513. The liquid ejection unit 511 is disposed at the bottom of the head housing 514. The liquid ejection unit 511 is exposed to the outside at the bottom surface of the head housing 514.

[0028] The downstream end of the liquid supply path 52 in the ink flow direction is connected to the common path 512. Two liquid supply paths 52 are connected to one common path 512 provided in one liquid jet head 51. One liquid supply path 52 is connected to one end side of the common path 512 in the paper width direction Dw, and the other liquid supply path 52 is connected to the other end side of the common path 512 in the paper width direction Dw. The upstream end of the liquid supply path 52 in the ink flow direction is connected to an ink tank (not shown). The liquid supply path 52 includes, for example, a tube and a connecting member that connects multiple tubes. The liquid supply path 52 supplies ink (liquid) to the liquid jet head 51.

[0029] The cleaning liquid supply path 53 has a downstream end in the cleaning liquid flow direction connected to a cleaning liquid supply unit (not shown). The cleaning liquid supply unit is provided on one end side of the liquid ejection unit 511 in the paper width direction Dw. The cleaning liquid supply unit includes a cleaning liquid supply surface adjacent to the ink ejection surface 511a in the paper width direction Dw, and a plurality of cleaning liquid supply ports opening in the cleaning liquid supply surface. The cleaning liquid supply ports supply cleaning liquid to the cleaning liquid supply surface. The cleaning liquid is carried to the ink ejection surface 511a by a wiper (not shown) and is used to clean the ink ejection surface 511a.

[0030] An upstream end of the cleaning liquid supply path 53 in the cleaning liquid flow direction is connected to a cleaning liquid tank (not shown). The cleaning liquid supply path 53 includes, for example, a tube and a connecting member that connects a plurality of tubes. The cleaning liquid supply path 53 supplies the cleaning liquid to a cleaning liquid supply unit of the liquid ejection head 51.

[0031] The main body housing 54 has a tubular shape that extends along the paper width direction Dw and has a rectangular cross section as seen from the paper width direction Dw. The lower surface of the main body housing 54 faces the paper P that is adsorbed and held on the upper surface of the first belt conveyor 41 and conveyed, and is parallel to the surface of the paper P.

[0032] Main body housing 54 includes a gutter-shaped member 541 that is open at its upper end and at both ends in the paper width direction Dw, and an upper cover 542 that covers the upper end opening of gutter-shaped member 541. Main body housing 54 also has an intake port 543 arranged at one end in the paper width direction Dw, and an exhaust port 544 arranged at the other end in the paper width direction Dw.

[0033] The main body housing 54 houses and holds therein the three liquid jet heads 51. The liquid jetting parts 511 of the three liquid jet heads 51 are exposed to the outside at the bottom surface of the main body housing 54. That is, to be more specific, the main body housing 54 covers and houses inside the liquid jet heads 51, except for the liquid jetting parts 511.

[0034] The fan 55 is disposed at the intake port 543 of the main body housing 54. For example, two fans 55 are arranged side by side along the paper transport direction Dc. The fan 55 draws in air from outside the main body housing 54 and sends it into the inside of the main body housing 54. Furthermore, the fan 55 circulates air between the main body housing 54 and the head housing 514. This makes it possible to cool the control board 513 of the liquid ejecting head 51 via the head housing 514.

[0035] The upper cover 542 of the main body housing 54 is formed in a flat plate shape and has a plurality of through holes 5421. The through holes 5421 pass through the upper cover 542 in the vertical direction. The through holes 5421 are disposed in the vicinity of the liquid ejecting head 51 housed inside the main body housing 54.

[0036] The liquid supply path 52 and the cleaning liquid supply path 53 are inserted from the outside of the main body housing 54 into the inside of the main body housing 54 through the through hole 5421, and connected to the liquid jet head 51. That is, the liquid supply path 52 is inserted from the outside of the main body housing 54 into the inside of the main body housing 54 in the vicinity of the liquid jet head 51, and is connected to the liquid jet head 51.

[0037] According to the above configuration, most of the liquid supply path 52 is disposed outside the main body housing 54, except for the vicinity of the connection point with the liquid jet head 51. This makes it possible to prevent the liquid supply path 52 from contacting the air flow generated by the operation of the fan 55 as much as possible. Therefore, it is possible to cool the control board 513 of the liquid jet head 51 without cooling the liquid supply path 52. In other words, it is possible to properly manage the temperature of the ink and achieve high-quality recording.

[0038] In order to shorten the length of the liquid supply path 52 arranged inside the main body housing 54, the liquid supply path 52 is drawn out from an outer wall of the main body housing 54 in a direction perpendicular to the paper width direction Dw, which is the air flow direction inside the main body housing 54, to the outside of the main body housing 54. In this embodiment, the liquid supply path 52 is drawn out from the upper lid 542, which is one of such outer walls. When the liquid supply path 52 is drawn out from the upper lid 542, the through hole 5421 is arranged directly above the connection point between the liquid supply path 52 and the liquid ejection head 51 (in a direction perpendicular to both the paper width direction Dw and the paper transport direction Dc). If the liquid supply path 52 is arranged on a straight line connecting the connection point between the liquid supply path 52 and the liquid ejection head 51 and the through hole 5421, the length of the liquid supply path 52 arranged inside the main body housing 54 will be the shortest.

[0039] In the case where the liquid supply path 52 is drawn out from a certain outer wall of the main body housing 54, the shortest length of the liquid supply path 52 in the main body housing 54 as described above, which is required to draw the liquid supply path 52 from that outer wall, is defined as L. Since the liquid supply path 52 is inserted from the outside to the inside of the main body housing 54 in the vicinity of the liquid ejection head 51, the length of the liquid supply path 52 in the main body housing 54 is 1.5 times or less of the above-mentioned L. The length of the liquid supply path 52 in the main body housing 54 may be 1.3 times or less of the above-mentioned L, or may be 1.1 times or less.

[0040] Furthermore, the length of the liquid supply path 52 inside the main body housing 54 may be one-fifth or less, or one-tenth or less, of the length of the path through which the liquid supply path 52 supplies liquid to the liquid jet head 51. The length of the path of the liquid supply path 52 here specifically refers to the length from the connection point between the liquid supply path 52 and the liquid jet head 51 inside the main body housing 54 under consideration to the connection point between the liquid supply path 52 and the ink tank at the upstream end of the ink flow direction of the liquid supply path 52.

[0041] 8, the control board 513 is disposed adjacent to the inner surface of the head housing 514. With this configuration, the heat of the control board 513 is transferred to the head housing 514 and is easily dissipated to the outside of the head housing 514. Therefore, it is possible to improve the effect of cooling the control board 513 via the head housing 514.

[0042] 4, 5, and 6, the intake port 543 is disposed at one end of the main body housing 54 in the paper width direction Dw. The exhaust port 544 is disposed opposite the intake port 543 at the other end of the main body housing 54 in the paper width direction Dw, which is opposite the intake port 543. As described above, the main body housing 54 has a tubular shape extending along the paper width direction Dw. As a result, the air circulation path caused by the operation of the fan 55 extends linearly from the intake port 543 to the exhaust port 544 within the main body housing 54.

[0043] According to this configuration, the airflow generated by the operation of fan 55 can be smoothly circulated within main body housing 54. Therefore, cool air can be constantly blown onto control board 513, and control board 513 can be effectively cooled.

[0044] 4, 5, and 6, the air flow path created by the operation of the fan 55 extends in the paper width direction Dw perpendicular to the transport direction Dc of the paper P onto which the ink is ejected by the liquid ejection head 51. This configuration makes it possible to minimize the area occupied by the air flow path and allow air to flow smoothly. This makes it possible to miniaturize the liquid ejection device 50.

[0045] 4 and 6, the intake port 543 is disposed at one end of the main body housing 54 in the paper width direction Dw (lower right in FIGS. 4 and 6) and outside the paper width direction Dw with respect to the facing area with the paper P. The exhaust port 544 is disposed at the other end of the main body housing 54 in the paper width direction Dw (upper left in FIGS. 4 and 6) and outside the paper width direction Dw with respect to the facing area with the paper P. In other words, the intake port 543 and the exhaust port 544 are disposed outside the paper width direction Dw with respect to the facing area with the paper P with the main body housing 54.

[0046] According to this configuration, it is possible to prevent the airflow generated by the operation of the fan 55 from affecting the ejection of ink from the ink ejection nozzles 5111. This makes it possible to suppress deviation in the landing position of the ink droplets, thereby realizing high quality recording.

[0047] 8, the liquid jet head 51 includes a heater 515. The heater 515 is disposed in the vicinity of the liquid jet unit 511. More specifically, the heater 515 is disposed above the liquid jet unit 511 and adjacent to and above the common passage 512. The heater 515 heats the liquid jet unit 511.

[0048] According to this configuration, it is possible to prevent the temperature of the ink ejection nozzle 5111 from dropping too much due to the airflow generated by the operation of the fan 55. In other words, it is possible to properly manage the temperature of the ink ejection nozzle 5111, and it is possible to prevent the ink viscosity from increasing or decreasing too much. This allows the liquid ejection device 50 to appropriately eject (spray) ink onto the paper P, making it possible to achieve high-quality recording.

[0049] Furthermore, according to the above embodiment, the inkjet recording apparatus 1 uses the liquid ejecting apparatus 50 configured as above to eject ink onto the paper P to record an image. This makes it possible for the inkjet recording apparatus 1 to cool the control board 513 of the liquid ejecting head 51 without cooling the liquid supply path 52 through which the ink flows. Therefore, the inkjet recording apparatus 1 can properly manage the ink temperature and achieve high-quality recording.

[0050] Although an embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. [Industrial Applicability]

[0051] The present invention can be used in liquid ejecting apparatuses and ink jet recording apparatuses. [Explanation of symbols]

[0052] 1 Inkjet recording device 5 Recording section 50, 50B, 50C, 50M, 50Y liquid injection device 51, 51B, 51C, 51M, 51Y Liquid jet head 52 Liquid supply path 54 Main unit housing 55 Fans 511 Liquid injection part 512 Common passage 513 Control Board 514 Head housing 515 Heater 543 Air Intake 544 Exhaust port 5111 Ink ejection nozzle

Claims

1. a liquid ejection head including a liquid ejection unit that ejects liquid onto a recording medium, a control board that controls an operation of the liquid ejection unit, and a head housing that covers and accommodates the control board; a liquid supply path that supplies the liquid to the liquid jet head; a main body housing that covers and houses a portion of the liquid ejection head other than the liquid ejection unit; a fan for circulating air between the main body housing and the head housing; Equipped with The main body housing includes: an intake port disposed at one end of the main body housing; an exhaust port disposed opposite the intake port at another end of the main body housing, the other end being opposite the intake port; Equipped with an air flow path caused by the operation of the fan extends linearly within the main body housing from the air intake to the air exhaust; the liquid supply path is inserted from the outside to the inside of the main body housing in the vicinity of the liquid ejection head and is connected to the liquid ejection head; In the main body housing, the two liquid supply paths are connected to the liquid ejection head, one of the liquid supply paths is connected to the exhaust port side of the liquid ejection head, and the other of the liquid supply paths is connected to the intake port side of the liquid ejection head, with respect to an air flow direction inside the main body housing; a head housing interposed between the liquid supply path connected to the exhaust port side and the intake port in the air flow direction inside the main body housing;

2. The liquid ejecting apparatus according to claim 1 , wherein the control board is disposed adjacent to an inner surface of the head housing.

3. 3. The liquid ejection apparatus according to claim 1, wherein the liquid ejection head includes a heater disposed near the liquid ejection unit to heat the liquid ejection unit.

4. The liquid ejecting apparatus according to claim 1 , wherein the air flow path extends in a width direction perpendicular to a transport direction of the recording medium onto which the liquid is ejected by the liquid ejecting head.

5. The liquid ejecting apparatus according to claim 4 , wherein the intake port and the exhaust port are disposed on the outer side in the width direction of the main body housing with respect to a region facing the recording medium.

6. 6. An inkjet recording apparatus that uses the liquid ejecting apparatus according to claim 1 to eject ink onto the recording medium to record an image.

Images