Inkjet recording device

Abstract

This invention provides an inkjet recording device equipped with an ink mist suction mechanism that significantly reduces the amount of exhaust piping required. [Solution] The device comprises: a plurality of recording heads that record images on a recording medium that moves relative to it in a first direction; a plurality of mist suction units provided corresponding to each of the plurality of recording heads, each having a mist suction port and a mist discharge port; a collection member extending in a second direction intersecting the first direction, having a space communicating with the plurality of mist discharge ports and an exhaust port, for collecting and exhausting air containing ink mist that flows in from the mist discharge ports; a carriage on which the plurality of mist suction units and the collection member are mounted; an exhaust chamber that exhausts air from the space of the collection member with the exhaust port connected to the connection port; and a switching means that switches between a first state in which the exhaust port and the connection port are connected and a second state in which the exhaust port and the connection port are not connected by moving the carriage relative to the exhaust chamber in a second direction.

Description

Technical Field

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

Background Art

[0002] Conventionally, a recording head in which a plurality of nozzles for ejecting ink are arranged to perform image recording with a predetermined recording width is used, and the recording head and the recording medium are relatively moved in a conveyance direction intersecting the direction in which the recording width extends. An inkjet recording apparatus that prints by ejecting ink while moving is widely used.

[0003] In such an inkjet recording apparatus, ink mist, which is fine mist-like ink, may be generated when ink is ejected from the nozzles. The generation of such ink mist may cause deterioration of image quality due to adhesion to the recording medium, ejection failure of the recording head due to adhesion and deposition around the recording head, and the like.

[0004] Particularly, in the case of an inkjet recording apparatus of a single-pass system in which image recording can be completed during one execution of the relative movement between the recording head and the recording medium, since the image recording speed is generally high, ink is ejected at high speed and in large quantities. Therefore, the generation of ink mist can occur more significantly. Further, when adopting such a single-pass system, in order to widen the recording width, a plurality of recording heads may be arranged in the direction in which the recording width extends. For example, a staggered arrangement in which the recording heads are arranged so as to overlap in the direction of the recording width and the positions of the recording heads are shifted in the conveyance direction may be used.

[0005] Therefore, various inkjet recording apparatuses provided with a mechanism for collecting the generated ink mist have been proposed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] These documents disclose inkjet recording devices equipped with a wide mist suction mechanism that corresponds to the full recording width, and inkjet recording devices in which multiple mist suction mechanisms are arranged in a horizontal line in the printing width direction. However, all of the disclosed mist suction mechanisms have a single wide, horizontally elongated continuous mist suction port. In other words, mist from multiple heads is collected by a single mist suction mechanism. Therefore, to ensure reliable mist collection, it is effective to arrange multiple mist suction mechanisms corresponding to each of the multiple recording heads.

[0008] However, if multiple mist suction mechanisms are provided for each of the multiple recording heads, the number of pipes required for air discharge to collect ink mist from each mist suction mechanism will be large, potentially severely impairing maintainability. Furthermore, while it is necessary to move the inkjet printer to perform maintenance on the inkjet head, moving the air discharge pipes as well could lead to an increase in the size of the equipment and the number of parts.

[0009] This invention has been made in view of the above problems, and provides an inkjet recording apparatus equipped with an ink mist suction mechanism that solves the above problems and significantly reduces the amount of exhaust piping. [Means for solving the problem]

[0010] To achieve the above objective, the inventors of the present invention, through diligent effort, have discovered the following configuration.

[0011] In other words, the present invention provides an inkjet recording apparatus comprising a plurality of recording heads, each having a plurality of nozzles for ejecting ink, wherein ink is ejected from the plurality of recording heads to a recording medium that moves relative to the plurality of recording heads in a first direction to perform a recording operation, A plurality of mist suction units are provided corresponding to each of the plurality of recording heads, each having a mist suction port for sucking up ink mist generated from the recording head and a mist discharge port for discharging the sucked-up ink mist. A member extending in a second direction intersecting the first direction, comprising a space communicating with a plurality of mist outlets and an exhaust port for exhausting air containing ink mist from the space, and a converging member for converging air containing ink mist flowing in from the plurality of mist outlets into the space and exhausting it from the exhaust port, A carriage for mounting the plurality of mist suction units and the collection member, An exhaust chamber having a connection port for connecting to the exhaust port, and which exhausts air from the space of the collection member through the exhaust port when the exhaust port is connected to the connection port, The device is characterized by having a switching means that switches the connection state between the exhaust port and the connection port between a first state in which the exhaust port and the connection port are connected and a second state in which the exhaust port and the connection port are not connected, by moving the carriage relative to the exhaust chamber in the second direction.

[0012] Furthermore, the device is equipped with a carriage moving means for moving the carriage in the second direction, and the switching means is characterized in that it switches between the first state and the second state by moving the carriage in the second direction using the carriage moving means.

[0013] Furthermore, the inkjet recording apparatus further comprises another recording head arranged at a different position from the plurality of recording heads with respect to the first direction, another mist suction unit corresponding to the other recording head, and another aggregation member corresponding to the other mist suction unit, and the carriage is further mounted with the other mist suction unit and the other aggregation member. The exhaust chamber has a plurality of connection ports corresponding to each of the plurality of exhaust ports of the aggregation member and the other aggregation member, The first state is a state in which each of the plurality of exhaust ports and each of the plurality of connection ports are connected simultaneously. The second state described above is a state in which each of the plurality of exhaust ports and each of the plurality of connection ports are simultaneously disconnected. The switching means is characterized by switching between the first state and the second state by moving the carriage relative to the exhaust chamber in the second direction.

[0014] Furthermore, each of the plurality of connection ports is connected to the exhaust chamber via a ventilation path for allowing air containing ink mist to pass from the plurality of exhaust ports, and the length of each of the plurality of ventilation paths is substantially constant.

[0015] Furthermore, the carriage is characterized in that it is further equipped with the plurality of recording heads.

[0016] The mist suction port is characterized by having a width wider than the image recording width by the plurality of nozzles of the recording head.

[0017] The opening size of one of the plurality of mist suction units connected to the aggregation member is less than the opening size of the other mist outlets located further away from the exhaust port than the one mist outlet. [Effects of the Invention]

[0018] According to the present invention, by adopting the above configuration, it is possible to solve the above problems and provide an inkjet recording apparatus provided with an ink mist suction mechanism that significantly reduces the piping for exhaust.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic perspective view showing the configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 2] It is a bottom view of the carriage for explaining the arrangement relationship between the nozzle surface and the mist suction port. [Figure 3] It is a schematic perspective view showing the configuration of an inkjet recording apparatus according to another embodiment of the present invention. [Figure 4] It is a schematic diagram showing the switching situation between connection and disconnection in the exhaust means and the mist suction mechanism. [Figure 5] It is a perspective view of the mist suction mechanism equipped with an ink recovery mechanism. [Figure 6] It is a cross-sectional view of the mist suction mechanism and the ink recovery mechanism. [Figure 7] It is a cross-sectional view showing a modified example of the mist suction mechanism. [Figure 8] It is a schematic diagram for explaining the operation of switching the opening and closing of the control valve of the ink flow control member.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0021] FIG. 1 is a schematic perspective view showing the configuration of an inkjet recording apparatus according to an embodiment of the present invention, schematically showing a configuration example of the apparatus. An inkjet recording apparatus 100 according to an embodiment of the present invention includes recording heads 1a to 1d, mist suction mechanisms 2a, 2b, ink recovery mechanisms 3a, 3b, a carriage 4, carriage moving means 5, and exhaust means 6.

[0022] At least one of the recording head 1 and the recording medium 7 is movable in the transport direction by a moving means (not shown), thereby enabling relative movement between the recording head 1 and the recording medium 7. The moving means can be selected appropriately depending on the structure of the device and the shape of the recording medium 7. For example, a ball screw, linear motor, robot arm, etc. can be used as the moving means for moving the recording head 1. Also, for example, a table connected to a drive means, a conveyor, a roll-to-roll transporter, a robot arm, etc. can be used as the moving means for moving the recording medium 7.

[0023] Furthermore, this inkjet recording device 100 can be applied to either a multi-pass method (also called a serial head method) or a single-pass method (also called a line head method). It is particularly suitable for the single-pass method, which tends to generate a large amount of ink mist in a short time when high-speed printing is performed. The recording medium 7 can be various substrates and materials such as paper, film, sheets, steel plates, wood, glass plates, other plate materials, cans, bottles, other cylindrical objects, boxes, containers, etc., and is not limited to any particular type, but is particularly suitable for wide plate-shaped substrates or sheet-shaped substrates.

[0024] In the example shown in Figure 1, the carriage 4 is equipped with a total of four recording heads 1a to 1d. As shown in the figure, two rows of recording heads are spaced apart in the recording width direction intersecting the transport direction, and these rows are offset in the transport direction. Furthermore, the recording heads are arranged in a staggered pattern, offset in the recording width direction, so that a portion of each recording width overlaps, thereby enabling the recording of wide images. Four mist suction boxes 21a to 21d, corresponding to each of the multiple recording heads 1a to 1d, are positioned along each row of the recording heads.

[0025] Figure 2 is a bottom view of the carriage illustrating the arrangement of the nozzle surface and the mist suction port. When viewed from the bottom, each of the recording heads 1a to 1d has nozzle surfaces 11a to 11d, each having multiple nozzles for ejecting ink arranged in a predetermined direction (recording width direction). The ink is ejected from the nozzles onto the recording medium 7 according to the image data to record the image. In the inkjet recording device 100 for recording color images, although not specifically shown in the example in Figure 1, a recording head 1 for ejecting four colors of ink—black (K), cyan (C), magenta (M), and yellow (Y)—is usually arranged. In addition, if necessary, recording heads for ejecting special color inks such as white (W) and clear (CL) required for image formation can be further installed, and recording heads corresponding to colors that are not needed can be omitted, and various liquid agents can be ejected instead of color inks. Furthermore, as a recording head, one that can eject one color of ink may be used, or one that can eject two or more different types of ink (multi-color ink compatible recording head) may be used.

[0026] The ink used for image recording can be any type without particular restrictions, such as active light-curable ink, water-based ink, or solvent-based ink. Although not specifically shown in the example in Figure 1, if the ink used for image recording is an active light-curable ink, the carriage 4 can be further equipped with an appropriate active light irradiation device, and active light irradiation can be performed as needed after the image recording operation. The active light irradiation device can be selected appropriately depending on the properties of the active light-curable ink used, such as an ultraviolet irradiation device or an electron beam device. In addition, the lamp used in the ultraviolet irradiation device can be selected in an appropriate form, such as mercury, metal halide, or LED. If the ink used for image recording is a solvent-based ink or water-based ink, various heat drying devices can be appropriately arranged instead.

[0027] As shown in Figure 2, the mist suction ports 211a to 211d of the mist suction boxes 21a to 21d are arranged to correspond to the nozzle surfaces 11a to 11d of each of the recording heads 1a to 1d. This configuration allows the nozzle surfaces 11a to 11d and the mist suction ports 211a to 211d to be placed in close proximity, ensuring that ink mist generated from the recording heads 1a to 1d is reliably sucked up and collected from the corresponding mist suction ports 211a to 211d. In this way, instead of arranging a mist suction mechanism with one wide mist suction port in the recording width direction for multiple recording heads, by arranging one mist suction port for each nozzle surface, even when the recording heads are arranged in a staggered pattern, the mist suction ports can be placed as close to the recording heads as possible, avoiding the staggered arrangement, thereby more reliably collecting ink mist.

[0028] In Figure 2, recording head 1b is positioned at a first distance T1 in the recording width direction relative to recording head 1a. Recording head 1c is positioned at a second distance T2 in the transport direction relative to recording head 1a, and recording head 1d is positioned at a first distance T1 in the recording width direction relative to recording head 1c. Furthermore, recording heads 1c and 1d are arranged in a staggered pattern with a offset in the recording width direction relative to recording heads 1a and 1b. In Figure 2, recording head 1c is positioned corresponding to the area between recording head 1a and recording head 1b. In addition, mist suction port 211a is positioned at a third distance T3 in the transport direction relative to recording head 1a, and mist suction port 211b is positioned at a distance corresponding to the first distance T1 in the recording width direction relative to mist suction port 211a, and at a third distance T3 in the transport direction relative to recording head 1b. Furthermore, the mist suction port 211c is positioned at a distance corresponding to a second distance T2 from the mist suction port 211a in the transport direction, and at a distance of a fourth distance T4 from the recording head 1c in the transport direction. Moreover, the mist suction port 211d is positioned at a distance corresponding to a second distance T2 from the mist suction port 211b in the transport direction, and at a distance of a fourth distance T4 from the recording head 1d in the transport direction.

[0029] The first distance T1 is set to an appropriate distance such that, in order to achieve a predetermined recording width, the spacing between the multiple nozzles arranged on the nozzle surfaces 11a to 11d of the recording heads 1a to 1d is taken into consideration, and the ends of the recording heads 1a and 1b and the ends of the recording heads 1c and 1d are, if necessary, partially overlapped in the recording width direction.

[0030] The second distance T2 is set taking into consideration the arrangement of the recording heads 1a to 1d and the mist suction boxes 21a to 21d, as well as the arrangement of any additional active light irradiation devices placed on the carriage 4.

[0031] The third distance T3 and the fourth distance T4 are set appropriately considering the ink mist generation conditions and transport environment. From the viewpoint of reliably collecting the ink mist generated from the recording head 1 by the corresponding mist suction box 21, it is preferable that at least the third distance T3 and the fourth distance T4 are closer than the second distance T2. In this embodiment, the third distance T3 and the fourth distance T4 are set to approximately the same distance. By setting the third distance T3 and the fourth distance T4 to approximately the same distance, variations in the distance between the nozzle surfaces 11a to 11d and the mist suction port 211a to mist suction port 211d can be reduced, maintaining a relatively uniform ink mist suction condition while contributing to the simplification of the device configuration. However, the configuration is not limited to setting the third distance T3 and the fourth distance T4 to approximately the same distance. The third distance T3 and the fourth distance T4 can also be set to appropriately different distances, taking into account various factors such as the shape of the device, the arrangement of each component, the performance of the ink used, the airflow generated around the nozzle surface, and the performance of the recording head.

[0032] Furthermore, the relationship between the first distance T1 to the fourth distance T4 described above represents only one embodiment and can be modified within a range that allows for appropriate image recording and achieves the appropriate ink mist suction effect. For example, it is conceivable that the distance between nozzle surface 11a and nozzle surface 11b and the distance between nozzle surface 11c and nozzle surface 11d may be made different as needed, and it is also conceivable that the distance between nozzle surface 11a and mist suction port 211a, and the distances between nozzle surfaces 11b to nozzle surface 11d and mist suction ports 211b to mist suction ports 211d may be made different.

[0033] Furthermore, as shown in Figure 1, the groups of mist suction boxes 21a and 21b, and mist suction boxes 21c and 21d, are connected to aggregating members 22a and 22b, which extend in the recording width direction, thereby constituting mist suction mechanisms 2a and 2b. The air containing ink mist sucked in by mist suction boxes 21a and 21b is collected by aggregating member 22a and exhausted from exhaust port 221a. Similarly, the air containing ink mist sucked in by mist suction boxes 21c and 21d is collected by aggregating member 22b and exhausted from exhaust port 221b. Furthermore, the mist suction mechanism 2a and the mist suction mechanism 2b are each equipped with an ink recovery mechanism 3a and an ink recovery mechanism 3b, respectively, to recover the liquefied ink accumulated in the mist suction mechanism 2a and the mist suction mechanism 2b and to prevent ink leakage from the mist suction mechanism 2a and the mist suction mechanism 2b.

[0034] The arrangement and number of recording heads 1 and mist suction mechanisms 2 are not limited to those shown. Depending on the shape of the recording medium 7, the size of the inkjet recording device 100, the number of recording heads 1, etc., the mist suction mechanism 2 with a configuration for arranging the mist suction box 21 can be appropriately selected. The arrangement of the mist suction mechanism 2 can be appropriately selected to be upstream or downstream in the transport direction relative to the recording head 1. The width of the opening of the mist suction port 211 can be set as appropriate, but from the viewpoint of reliably collecting ink mist, it is preferable to set it to a width corresponding to the image recording width by the nozzles constituting the nozzle surface 11 of the recording head 1. Furthermore, from the viewpoint of preventing ink mist from adhering to both ends of the opening width of the mist suction port 211, it is effective to make the width of the opening of the mist suction port 211 wider than the image recording width by the nozzles constituting the nozzle surface 11 of the recording head 1. The shape of the aggregation member 22 is not limited to that shown in Figure 1, and an appropriate shape can be selected.

[0035] In the example shown in Figure 1, the carriage 4 is equipped with recording heads 1a to 1d, mist suction mechanisms 2a and 2b, and ink recovery mechanisms 3a and 3b. A carriage moving means 5 is connected to the carriage 4, and the carriage 4 can be moved in the recording width direction by the drive of the carriage moving means 5, which is controlled by a control means (not shown). Linear motion means such as a ball screw or a linear motor can be used as the carriage moving means 5. In addition, on the exhaust port 221 side of the aggregation member 22 in the recording width direction of the inkjet recording device 100, an exhaust means 6 is arranged, which consists of an exhaust chamber 61 equipped with multiple exhaust ports 221a and 221b, and connection ports 62a and 62b corresponding to the exhaust ports 221a and 221b, and an exhaust blower 63 that exhausts the air in the exhaust chamber 61. In addition, in the direction opposite to where the exhaust means 6 is located in the recording width direction, a retraction position 8 is arranged for cleaning the recording heads 1a to 1d and the bottom surface of the carriage 4, and for storing the recording heads 1a to 1d.

[0036] Furthermore, with respect to the recording width direction of the inkjet recording device 100, an exhaust means 6 is arranged on the side where the exhaust ports 221a and 221b are located. The exhaust means 6 consists of an exhaust chamber 61 that collects air containing ink mist flowing in from each of the exhaust ports 221a and 221b, with connection ports 62a and 62b arranged in a number corresponding to the number of exhaust ports (two in the example of Figure 1), and an exhaust blower 63 for discharging the air from the exhaust chamber 61. The air containing ink mist exhausted from the exhaust ports 221a and 221b connected to the connection ports 62a and 62b is collected in the exhaust chamber 61 and discharged from the exhaust chamber 61 by driving the exhaust blower 63.

[0037] Here, another configuration example of the exhaust means 6 will be described. Figure 3 is a schematic perspective view showing the configuration of an inkjet recording apparatus 100 according to another embodiment of the present invention. In the inkjet recording apparatus 100 of Figure 3, the exhaust means 6 is provided with ventilation paths 64a and 64b between each of the connection ports 62a and 62b and the exhaust chamber 61. According to this configuration, air containing ink mist that flows in from each of the exhaust ports 221a and 221b connected to each of the connection ports 62a and 62b passes through each of the ventilation paths 64a and 64b, reaches the exhaust chamber 61 and is collected. Here, a configuration in which the length L1 of the ventilation path 64a and the length L2 of the ventilation path 64b are approximately the same is assumed. By adopting this configuration, the distance from the exhaust blower 63 to the exhaust port 221a and the distance to the exhaust port 221b are kept approximately constant, thereby improving the uniformity of the exhaust air pressure applied to each of the exhaust ports 221a and 221b by the exhaust blower 63. This stabilizes the exhaust air pressure applied to each of the mist suction mechanisms 2a and 2b, thereby improving the stability of the ink mist suction operation. There are no particular limitations on the shape, material, etc., of the ventilation path 64, and appropriate materials such as pipes, ducts, and hoses can be selected.

[0038] Here, we will explain the switching between connection and disconnection between the exhaust means 6 and the mist suction mechanism 2. As described above, it is necessary to collect the air containing ink mist discharged from the mist outlets 212a to 212d of each of the multiple mist suction boxes 21a to 21d using the aggregation members 22a and 22b and exhaust it from the exhaust ports 221a and 221b. Therefore, it is necessary to connect the exhaust ports 221a and 221b to the exhaust means 6 in some way. However, in the inkjet recording device 100 of this embodiment, it is necessary to move the carriage 4 to retract the recording heads 1a to 1d from above the transport means of the recording medium 7 for maintenance and storage of the recording heads 1a to 1d. For this reason, if the exhaust ports 221a and 221b and the exhaust means 6 are connected by piping, when the carriage 4 is moved, the connecting piping will also have to be moved, which may lead to complexity in the device configuration and damage to the piping due to the movement. Therefore, in the inkjet recording device 100 of this embodiment, the exhaust port 221 and the exhaust means 6 are connected when image recording is performed, and when the recording head 1 is not being recorded and is being stored or maintained, the exhaust ports 221a and 221b and the exhaust means 6 are disconnected.

[0039] Figure 4 is a schematic diagram showing the switching between connection and disconnection in the exhaust means 6 and the mist suction mechanism 2. When image recording is performed, the carriage 4 is moved towards the exhaust means 6 by driving the carriage moving means 5, as shown in Figure 4(a), thereby moving the carriage 4 above the recording medium 7 and connecting the exhaust ports 221a and 221b to the connection ports 62a and 62b of the exhaust chamber 61 of the exhaust means 6 (connected state). At this time, even if there are multiple aggregation members 22 corresponding to multiple mist suction mechanisms 2, as in this inkjet recording device 100, by providing multiple connection ports 62 corresponding to each of the multiple exhaust ports 221, all exhaust ports 221 can be connected to the exhaust means 6 with a single movement of the carriage 4. Also, by driving the carriage moving means 5, the carriage 4 is moved towards the retracted position 8, as shown in Figure 4(b), which disconnects the connection between the exhaust ports 221 and the exhaust means 6. Similarly, if there are multiple exhaust ports 221, all of them are disconnected from the exhaust means 6 (disconnected state). Thus, by configuring the system to switch between connected and disconnected states of the exhaust port 221 and connection port 62 in accordance with the movement of the carriage 4 to the image recording position and the movement to the retracted position 8, and by configuring the system so that the exhaust port 221 and exhaust means 6 are connected when image recording generates ink mist, the piping of the device can be significantly reduced with a simple device configuration, and the possibility of damage to the piping can be reduced by omitting the movement of the piping. In this embodiment, an example was used in which connection and disconnection are performed in the recording width direction which is substantially perpendicular to the transport direction, but other configurations can also be envisioned, such as a configuration in which the carriage 4 is moved in the direction of transporting the substrate to perform connection and disconnection, depending on the shape of the recording medium 7 and the shape of the device.

[0040] Next, a structural example of a mist suction mechanism 2 and an ink recovery mechanism 3 for recovering ink stored in the mist suction mechanism 2, which are applied to an inkjet recording apparatus 100 according to one embodiment of the present invention, will be described in detail.

[0041] Figure 5 is a perspective view of the mist suction mechanism equipped with a mist suction mechanism and an ink recovery mechanism. Figure 6 is a cross-sectional view of the mist suction mechanism and the ink recovery mechanism. Figures 5 and 6 refer to the mist suction mechanism 2a and the ink recovery mechanism 3a.

[0042] The configuration of the mist suction mechanism 2a in this embodiment will be described in detail. Each of the mist suction boxes 21a and 21b has a flow section 223 for circulating the ink mist sucked in from the mist suction port 211a. The mist suction boxes 21a and 21d are connected to a collection member 22a that extends in the recording width direction via mist outlets 212a and 212b, respectively, thereby forming a single mist suction mechanism 2a. The air containing ink mist sucked in by each of the mist suction boxes 21a and 21b of the mist suction mechanism 2a is collected in the collection member 22a via the flow section 223 in the mist suction box and exhausted from the exhaust port 221a.

[0043] Here, we will describe the aggregation member 22a of the mist suction mechanism 2a. In order to recover the ink mist collected from the mist suction port 211a of the mist suction box 21a and the mist suction port 211b of the mist suction box 21b, a means is needed to discharge the air containing the ink mist from the mist outlets 212a and 212b, which correspond to the mist suction boxes 21a and 21b, respectively. For this purpose, it would be necessary to connect exhaust piping to each of the mist outlets 212a and 212b. However, if piping corresponding to each of the multiple mist suction boxes is connected one by one, the amount of piping becomes large, affecting productivity and maintainability. Therefore, in the inkjet recording device 100 of this embodiment, multiple mist suction boxes 21 arranged in the recording width direction are connected by an aggregation member 22 that extends in the recording width direction, and are combined into a single mist suction mechanism 2, thereby significantly reducing the amount of piping required for exhaust from the mist suction boxes 21. Furthermore, since the mist suction box 21 and the aggregation member 22 are mounted on the same carriage 4 and move together as a single unit, long piping is not required to connect the mist suction box 21 and the aggregation member 22. This configuration is particularly effective in the case of a large inkjet recording device 100, where a large number of recording heads 1 are arranged and a large number of corresponding mist suction boxes 21 are also required. In addition, as in this embodiment, by separating the aggregation members 22 according to the arrangement position of the recording heads 1 in the transport direction, it is possible to reduce the variation in the distance from the mist suction port 211 to the aggregation member 22, making it possible to maintain a relatively uniform suction force applied to each mist suction port 211, and thus enabling reliable suction of ink mist.

[0044] The internal structure of the mist suction mechanism 2 and the internal structure of the ink recovery mechanism 3 will be described in detail below with reference to Figure 6, etc.

[0045] First, the internal structure of the mist suction mechanism 2 will be explained. The inside of the mist suction mechanism 2a forms a space that communicates from the mist suction ports 211a and 211b, through the flow section 223, to the exhaust port 221a of the collection member 22a, via the mist discharge ports 212a and 212b. In addition, a liquefaction promoting section is arranged inside the flow section 223 of each of the mist suction boxes 21a and 21b to promote the liquefaction of ink mist. In this example, multiple plate-shaped members, called baffles 213, are positioned to easily contact the ink mist as it passes through the flow section 223, and these baffles are positioned as liquefaction promoting sections to facilitate contact with the ink mist. Near the mist suction port 211a of the mist suction box 21a, an ink storage section 214 is arranged to store the ink that has liquefied when the ink mist comes into contact with the baffles 213. Furthermore, an ink storage section 222 is appropriately positioned inside the aggregation member 22a to store ink that has liquefied as air containing ink mist flows through the space within the aggregation member 22a. The internal configuration of the mist suction mechanism 2b is the same as that of the mist suction mechanism 2a.

[0046] Here, a modified version of the mist suction mechanism will be described. Figure 7 is a cross-sectional view showing a modified version of the mist suction mechanism. Figure 7 shows a modified mist suction mechanism 1002 in which four mist suction boxes 1021a to 1021d are connected to a single aggregation member 1022. From the viewpoint of performing stable ink mist suction, it is effective to maintain a relatively uniform suction force applied to each of the mist suction ports 1211a to 1211d. However, for the multiple mist suction boxes 1021a to 1021d mounted on the aggregation member 1022, a phenomenon may occur in which the suction force applied to the mist suction port 1211 corresponding to a mist outlet 1212 that is further away from the exhaust port 1221 connected to the exhaust means 6 that is exhausted by the exhaust blower 63 is weaker than the suction port 1211 corresponding to a mist outlet 1212 that is closer to the exhaust port 1221 connected to the exhaust means 6 that is exhausted by the exhaust blower 63 is weaker. Therefore, in the example shown in Figure 7, the opening width W of the mist outlet 1212 is set so that the opening width W1 of the mist outlet 1212a, which is closest to the exhaust port 1221, is the smallest, and the opening widths W2 of the mist outlet 1212b, W3 of the mist outlet 1212c, and W4 of the mist outlet 1212d increase in that order as the distance from the exhaust port 1221 increases. This configuration relatively weakens the suction force of the mist suction port 1211a corresponding to the mist outlet 1212a that is close to the exhaust port 1221, and relatively strengthens the suction force of the mist suction ports 1211b to 1211d corresponding to the mist outlets 1212b to 1212d that are farther from the exhaust port 1221. This configuration eliminates the unevenness of suction force caused by the difference in distance between the exhaust port 1221 and the mist outlets 1212a to 1212d, and makes it possible to maintain a relatively uniform suction force applied to each of the mist suction ports 1211a to 1211d. This configuration can also be achieved by other means, such as changing the opening width W of the mist outlets 1212a to 1212d, or by adjusting the opening area by connecting mesh members with different opening ratios to the mist outlets 1212a to 1212d.

[0047] Next, the internal structure of the ink recovery mechanism 3 will be described. As described above, the mist suction mechanism 2a is connected to the ink recovery mechanism 3a, which is equipped with a first ink flow path 312, a second ink flow path 313, an ink outlet 314, and an ink flow control member 32, and has ink recovery ports 311 corresponding to the mist suction boxes 21a and 21b and the aggregation member 22a, respectively. The ink storage sections 214 of the mist suction boxes 21a and 21b and the ink storage section 222 of the aggregation member 22 have ink recovery ports 311 of the ink recovery mechanism 3a for recovering the ink accumulated in the ink storage sections 214 and 222. The position of the ink storage section 222 can be set to an appropriate position. In the examples shown in Figures 5 and 6, the ink storage unit 222 and its corresponding ink recovery port 311 are located on the opposite side of the exhaust port 221a. However, considering that the liquefied ink from the ink mist moving through the aggregation member 22a tends to accumulate near the exhaust port 221a, which is in the direction of the ink mist's flow, a configuration in which the ink storage unit 222 and its corresponding ink recovery port 311 are located near the exhaust port 221a is also conceivable.

[0048] On the side of the first ink channel 312 opposite to the ink recovery port 311, an ink flow control member 32 is arranged in a number corresponding to each of the multiple ink recovery ports 311 to control the flow of ink recovered from the ink recovery port 311 and flowing through the first ink channel 312 and the second ink channel 313. The ink flow control member 32 allows the flow of ink from the ink recovery port 311 toward the ink discharge port 314, and a check valve may be appropriately applied to prevent backflow of ink due to the flow of ink in the opposite direction. In this embodiment, the ink flow control member 32 is configured with, in order from the side of the ink recovery port 311, an inlet opening 321 into which ink recovered from the ink recovery port 311 flows, a blocking member 322 to prevent the flow of ink within the ink flow control member 32, an elastic member 323 having elasticity to press the blocking member 322 toward the inlet opening 321, and an outlet opening 324 for discharging the ink from within the ink flow control member 32. The closure member 322 can be any member with a shape that can appropriately close / open the inlet opening 321, such as a valve body or a sphere; in the example in Figure 6, a spherical member is used. The elastic member 323 can be any member that can press the closure member 322 toward the inlet opening 321, and the arrangement relationship between the closure member 322 and the elastic member 323 can be appropriately selected; in the example in Figure 6, a spring body is used. It is preferable to set the elastic force of the elastic member 323 to an appropriate value so that the opening and closing of the inlet opening 321 by the closure member 322 is appropriately changed according to the negative pressure situation in the first ink flow path 312.

[0049] Furthermore, a second ink flow path 313 is connected to each of the multiple outflow openings 324 corresponding to each of the multiple ink flow control members 32, and these are all combined into a single second ink flow path 313 via branch pipes or the like (not shown), forming a space leading to the ink outlet 314. The ink outlet 314 is connected to a waste ink tank 34 that stores the ink recovered from the ink recovery port 311. A negative pressure applying means 33 is also connected to the ink recovery port 311 to the ink outlet 314 by applying negative pressure to the space from the ink recovery port 311 through the first ink flow path 312 and the second ink flow path 313, thereby causing the ink to flow from the ink recovery port 311 to the ink outlet 314. The negative pressure applying means 33 can be any appropriate method, such as a negative pressure pump. In the example in Figure 6, the negative pressure applying means 33 is configured to apply negative pressure to the first ink flow path 312 via the waste ink tank 34, but other configurations are also acceptable as long as negative pressure can be applied within the first ink flow path 312.

[0050] Based on the above explanation, the operation of ink mist suction by the mist suction mechanism 2 and the operation of ink recovery by the ink recovery mechanism 3 will be explained in order below.

[0051] First, let's explain the operation of ink mist suction by the mist suction mechanism 2.

[0052] When the inkjet recording device 100 performs image recording, the carriage 4 is moved above the recording medium 7 by the drive of the carriage moving means 5, and the exhaust port 221a of the aggregation member 22a and the exhaust port 221b of the aggregation member 22b are connected to the connection ports 62a and 62b of the exhaust chamber 61 (Figure 4(a)). As a result, a space is formed in which the mist suction ports 211a to 211d of each of the mist suction boxes 21a to 21d communicate with the exhaust chamber 61, and by driving the exhaust blower 63 connected to the exhaust chamber 61, an airflow is formed in this space from each of the mist suction ports 211a to 211d to the exhaust chamber 61, allowing ambient air to be drawn in from the mist suction ports 211a to 211d.

[0053] Subsequently, when image recording begins by ejecting ink onto the recording medium 7 from the nozzles located on the nozzle surfaces 11a to 11d of the recording heads 1a to 1d, ink mist is generated in the space around the bottom surface of the carriage 4, including the areas around the nozzle surfaces 11a to 11d, due to the ink ejection from each of the multiple recording heads 1a to 1d located on the carriage 4. The mist suction ports 211a to 211d of the mist suction boxes 21a to 21d, each of which is located corresponding to each of the nozzle surfaces 11a to 11d of the multiple recording heads 1a to 1d, are used to suck up the air around the carriage 4 containing the ink mist. Since the mist suction ports 211a to 211d are located close to each of the nozzle surfaces 11a to 11d and corresponding to each, the ink mist generated by the ink ejected from each of the nozzles 11a to 11d can be sucked up more reliably.

[0054] A portion of the ink mist collected from each of the mist suction ports 211a to 211d is accelerated to liquefy as it comes into contact with the baffle plates 213 located inside the mist suction boxes 21a to 21d, and the liquefied ink is stored in the ink storage unit 214 as it is consumed. Air containing unliquefied ink mist is discharged from each of the mist outlets 212a to 212d, passing through the space inside the mist suction boxes 21a to 21d. The air containing ink mist exhausted from each of the mist outlets 212a to 212d is collected in the aggregation members 22a and 22b. The ink mist may liquefy due to the ambient temperature and contact with the inner walls of the aggregation members 22a and 22b, and the ink that liquefies in the aggregation members 22a and 22b is stored in the ink storage unit 222 as it is consumed. The air containing the unliquefied ink mist is then exhausted into the exhaust chamber 61 through exhaust ports 221a and 221b, and the air containing ink mist from the mist suction mechanisms 2a and 2b is collected and finally exhausted from the exhaust chamber 61 by the exhaust blower 63.

[0055] Next, we will explain the operation of ink recovery by the ink recovery mechanism 3.

[0056] As described above, each of the multiple ink recovery ports 311 of the ink recovery mechanism 3, located in the ink storage section 214 or ink storage section 222 of the mist suction mechanism 2, comes into contact with the liquid surface of the ink stored in the ink storage section 214 or ink storage section 222. Due to the negative pressure applied to the first ink flow path 312 by the negative pressure applying means 33, ink is sucked out and recovered from each of the ink recovery ports 311. The ink recovered from each of the ink recovery ports 311 flows into the ink flow control member 32 through the inlet opening 321 of the ink flow control member 32 corresponding to each of the ink recovery ports 311, flows out through the outlet opening 324, flows into the second ink flow path 313 which is collected by branch pipes or the like as described above, and is discharged to the waste ink tank 34 through the ink discharge port 314.

[0057] The operation of the ink flow control member 32 will now be explained with reference to Figure 8.

[0058] In the example of this embodiment, where there are multiple ink recovery ports 311 and they are ultimately collected into a single second ink flow path 313 via branch pipes, if there is no member such as the ink flow control member 32, and all ink recovery ports 311 and the first ink flow path 312 are always in communication via the second ink flow path 313, then if some of the multiple ink recovery ports 311 are opened to the atmosphere without contacting the ink, all of the multiple first ink flow paths 312 will be connected to the atmosphere via the second ink flow path 313. As a result, even if the negative pressure applying means 33 is driven, an appropriate negative pressure may not be generated in all of the first ink flow paths 312, and ink may not be able to be drawn up from the ink recovery ports 311 that are in contact with the ink. If ink cannot be properly recovered from the ink storage section 214 and the ink storage section 222, there is a risk that the overflowing ink may leak from the mist suction mechanism 2a and the mist suction mechanism 2b, which may hinder stable mist suction operation.

[0059] Therefore, in the ink recovery mechanisms 3a and 3b of this embodiment, the ink flow control member 32 corresponding to the ink recovery port 311 that is in contact with the ink among the multiple ink recovery ports 311 is left open without its inlet opening 321 being blocked by the blocking member 322, allowing the ink to flow toward the outlet opening 324. In contrast, the ink flow control member 32 corresponding to the ink recovery port 311 that is not in contact with the ink and is open to the atmosphere has its inlet opening 321 blocked by the blocking member 322, keeping the section of the first ink flow path 312 from the ink flow control member 32 to the second ink flow path beyond the outlet opening 324 out of contact with the atmosphere. Implementing these processes using electronic valves, sensors, etc., would result in a large-scale device configuration and potentially increase manufacturing costs. Therefore, implementing these processes with a simple configuration as in this embodiment is effective. The configuration of this embodiment will be further described below.

[0060] Figure 8 is a schematic diagram illustrating the operation of switching the opening and closing of the closure member of the ink flow control member. The elastic force of the elastic member 323 is set to an appropriate elastic force so that when negative pressure is applied to the section of the first ink flow path 312 on the side of the outflow opening 324 of the ink flow control member 32, and the inflow opening 321 of the ink flow control member 32 is not filled with ink from the ink recovery port 311 and is open to the atmosphere, the closure member 322 is pressed toward the inflow opening 321, closing the inflow opening 321. On the other hand, when the inflow opening 321 of the ink flow control member 32 is filled with ink from the ink recovery port 311 and is not open to the atmosphere, the closure member 322 is pressed toward the outflow opening by the negative pressure applied by the negative pressure applying means 33, opening the inflow opening 321. As a result, when the ink recovery port 311 is open to the atmosphere, the blocking member 322 can maintain a state in which the inlet opening 321 is closed. This prevents the connection between the ink recovery port 311 and the first ink flow path 312, which are not filled with ink, from being cut off from the second ink flow path 313, thus avoiding the phenomenon in which the ink recovery port 311 and the first ink flow path 312, which are filled with ink, are connected to the atmosphere and negative pressure cannot be applied.

[0061] Conversely, when ink accumulates in the ink storage section 214 or ink storage section 222 and the ink recovery port 311 is filled with ink, the ink-filled ink recovery port 311 and the first ink flow path 312 are isolated from the atmosphere. As a result, the negative pressure in the space from the ink recovery port 311 to the inlet opening 321 of the ink flow control member 32 increases, pushing the closure member 322 toward the outlet opening 324 and moving toward the outlet opening 324, thereby opening the inlet opening 321. Once the ink has finished flowing and the ink recovery port 311 is opened to the atmosphere again, the space from the ink recovery port 311 to the inlet opening 321 of the ink flow control member 32 is connected to the atmosphere, and the ink flow control member 32 closes again.

[0062] With this configuration, the ink recovery mechanism 3 in this embodiment can reliably recover ink accumulated in the ink storage section 214 or ink storage section 222 with a simple configuration.

[0063] With the above configuration, we were able to realize an inkjet recording device 100 that can reliably collect ink mist while performing stable image recording.

[0064] In addition, in order to facilitate understanding of the present invention, explanations of known technical matters have been omitted as appropriate.

[0065] This invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of this invention is indicated not by the embodiments, but by the claims. Various modifications made within the scope of the claims and the equivalent scope of the meaning of the invention are considered to be within the scope of this invention. [Explanation of symbols]

[0066] 100 Inkjet Recording Devices 1a~1d Recording head 11a~11d Nozzle surface 2a~2b Mist suction mechanism 21a~21d Mist suction box 211a~211d Mist intake port 212a~212d Mist outlet 213 Baffle plate (liquefaction promotion section) 214 Ink storage section 22a~22b Aggregation member 221a~221b Exhaust port 222 Ink storage section 223 Distribution Department 3a~3b Ink recovery mechanism 311 Ink collection port 312 First Ink Channel 313 Second Ink Channel 314 Ink outlet 32 Ink flow control member 321 Inflow opening 322 Closure member 323 Elastic members 324 Outlet opening 33 Negative pressure application means 34 Waste ink tank 4 carriages 5. Carriage means of transport 6. Exhaust means 61 Exhaust Chamber 62a~62b Connection ports 63 Exhaust blower 64a~64b Ventilation paths 7 Recording medium 8 Evacuation position 1002 Mist suction mechanism (modified version) 1021a~d Mist suction box (modified version) 1211a~d Mist intake port (modified version) 1212a~d Mist outlet (modified version) 1022 Aggregation member (modified version) 1221 Exhaust vent (modified version)

Claims

1. In an inkjet recording apparatus comprising a plurality of recording heads, each having a plurality of nozzles for ejecting ink, the plurality of recording heads eject ink from the plurality of recording heads onto a recording medium that moves relative to the plurality of recording heads in a first direction, A plurality of mist suction units are provided corresponding to each of the plurality of recording heads, each having a mist suction port for sucking up ink mist generated from the recording head and a mist discharge port for discharging the sucked-up ink mist. A member extending in a second direction intersecting the first direction, comprising a space communicating with a plurality of mist outlets and an exhaust port for exhausting air containing ink mist from the space, and a converging member for converging air containing ink mist flowing in from the plurality of mist outlets into the space and exhausting it from the exhaust port, A carriage for mounting the plurality of mist suction units and the collection member, An exhaust chamber having a connection port for connecting to the exhaust port, and which exhausts air from the space of the collection member through the exhaust port when the exhaust port is connected to the connection port, An inkjet recording apparatus characterized by having a switching means that switches the connection state between the exhaust port and the connection port between a first state in which the exhaust port and the connection port are connected and a second state in which the exhaust port and the connection port are not connected, by moving the carriage relative to the exhaust chamber in the second direction.

2. The inkjet recording apparatus according to claim 1, further comprising a carriage moving means for moving the carriage in the second direction, wherein the switching means switches between the first state and the second state by moving the carriage in the second direction using the carriage moving means.

3. The inkjet recording apparatus further comprises another recording head arranged at a different position from the plurality of recording heads with respect to the first direction, another mist suction unit corresponding to the other recording head, and another aggregation member corresponding to the other mist suction unit, and the carriage is further mounted with the other recording head and the other aggregation member. The above has a plurality of connection ports corresponding to each of the plurality of exhaust ports that each of the aggregation member and the other aggregation member has, The first state is a state in which each of the plurality of exhaust ports and each of the plurality of connection ports are connected simultaneously. The second state described above is a state in which each of the plurality of exhaust ports and each of the plurality of connection ports are simultaneously disconnected. The inkjet recording apparatus according to claim 1 or 2, characterized in that the switching means switches between the first state and the second state by moving the carriage relative to the exhaust chamber in the second direction.

4. The inkjet recording apparatus according to claim 3, wherein each of the plurality of connection ports is connected to the exhaust chamber via a ventilation path for allowing air containing ink mist to pass from the plurality of exhaust ports, and the lengths of each of the plurality of ventilation paths are substantially the same.

5. The inkjet recording apparatus according to claim 1 or 2, characterized in that the carriage is further equipped with the plurality of recording heads.

6. The inkjet recording apparatus according to claim 1 or 2, characterized in that the mist suction port has a width corresponding to the image recording width by the plurality of nozzles of the recording head.

7. The inkjet recording apparatus according to claim 1 or 2, characterized in that the opening amount of one of the plurality of mist suction units connected to the aggregation member is less than the opening amount of the other mist outlets located further away from the exhaust port than the one mist outlet.

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