Inkjet recording apparatus

Abstract

Disclosed is an inkjet recording apparatus provided with an ink mist suction mechanism that significantly reduces exhaust piping. 【Solution means】A plurality of recording heads that record an image on a recording medium that relatively moves in a first direction, a plurality of mist suction units provided corresponding to each of the plurality of recording heads and having a mist suction port and a mist discharge port, an aggregation member extending in a second direction intersecting the first direction for aggregating and exhausting air containing ink mist flowing in from the mist discharge ports, the aggregation member having a space communicating with the plurality of mist discharge ports and an exhaust port, a carriage on which the plurality of mist suction units and the aggregation member are mounted, an exhaust chamber for exhausting the air in the space of the aggregation member with the exhaust port connected to a connection port, and switching means for switching 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 relatively moving the carriage in the second direction with respect to the exhaust chamber.

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, and ink is ejected while moving to perform image recording by an inkjet printing method. Inkjet recording apparatuses are 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] In particular, in the case of an inkjet recording apparatus of a single-pass system that can complete image recording while performing the relative movement between the recording head and the recording medium once, since the image recording speed is generally high, ink is ejected at high speed and in large quantities, so the generation of ink mist may 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 an inkjet recording apparatus equipped with a wide mist suction mechanism corresponding to the full width of the recording width, and an inkjet recording apparatus in which a plurality of mist suction mechanisms are arranged in a horizontal row in the printing width direction. However, all that is disclosed is a mist suction mechanism having a single wide horizontally long continuous mist suction port. That is, the mist from a plurality of heads is collected by a single mist suction mechanism. Therefore, in order to ensure reliable mist recovery, it is effective to arrange a plurality of mist suction mechanisms corresponding to each of the plurality of recording heads.

[0008] However, when preparing a plurality of mist suction mechanisms for each of the plurality of recording heads, there is a risk that a large amount of piping for discharging air for collecting ink mist from each of the mist suction mechanisms will result in significantly impaired maintainability. Also, although it is necessary to move the inkjet head for maintenance, moving the piping for discharging air may lead to an increase in the size of the apparatus and an increase in the number of parts.

[0009] The present invention has been made in view of the above problems, and provides an inkjet recording apparatus that solves the above problems and is equipped with an ink mist suction mechanism that significantly reduces the piping for exhaust. [Means for Solving the Problems]

[0010] In order to achieve the above object, as a result of intensive efforts, the inventor of the present invention has found the following configuration.

[0011] That is, in the present invention, an inkjet recording apparatus includes a plurality of recording heads in which a plurality of nozzles for ejecting ink are arranged, and performs a recording operation by ejecting 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 parts, each provided corresponding to each of the plurality of recording heads, and including a mist suction port for sucking ink mist generated from the recording head and a mist discharge port for discharging the sucked ink mist. A member extending in a second direction intersecting the first direction, including a space communicating with the plurality of mist discharge ports and an exhaust port for exhausting air containing ink mist in the space, and serving as an aggregating member for aggregating air containing ink mist flowing in from the plurality of mist discharge ports into the space and exhausting it from the exhaust port. A carriage for mounting the plurality of mist suction parts and the aggregating member. An exhaust chamber having a connection port for connecting to the exhaust port, and exhausting air in the space of the aggregating member from the exhaust port in a state where the exhaust port is connected to the connection port. Characterized by having switching means for switching 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 relatively moving the carriage in the second direction with respect to the exhaust chamber.

[0012] Further, it includes carriage moving means for moving the carriage in the second direction, and the switching means switches between the first state and the second state by moving the carriage in the second direction by the carriage moving means.

[0013] Further, the inkjet recording apparatus further includes another recording head arranged at a position different from the plurality of recording heads in the first direction, another mist suction unit corresponding to the another recording head, and another aggregation member corresponding to the another mist suction unit. The carriage is further equipped with the another mist suction unit and the another aggregation member. The exhaust chamber has a plurality of connection ports corresponding to each of the plurality of exhaust ports of each of the aggregation member and the another 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 simultaneously connected. The second state 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 in that the first state and the second state are switched by relatively moving the carriage in the second direction with respect to the exhaust chamber.

[0014] 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 through from the plurality of exhaust ports, and the length of each of the plurality of ventilation paths is substantially constant.

[0015] The carriage is further characterized in that the plurality of recording heads are further mounted thereon.

[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 amount of one of the mist discharge ports among the plurality of mist suction units connected to the aggregation member is less than the opening amount of another mist discharge port arranged at a position farther from the one mist discharge port with respect to the exhaust port.

Advantages 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

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

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. The 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 performing relative movement between the recording head 1 and the recording medium 7. The moving means can be appropriately selected according to the structure of the apparatus and the shape of the recording medium 7. For example, as the moving means for moving the recording head 1, a ball screw, a linear motor, a robot arm, etc. can be adopted. Also, for example, as the moving means for moving the recording medium 7, a table to which a driving means is connected, a conveyor, a roll-to-roll conveyor, a robot arm, etc. can be adopted.

[0023] Note that this inkjet recording apparatus 100 is applicable to both the multi-pass method (also called the serial head method) and the single-pass method (also called the line head method). It is suitable for the single-pass method in which high-speed printing is carried out and a large amount of ink mist tends to be generated in a short time. Also, the recording medium 7 is, for example, various base materials and materials such as paper, film, sheet, steel plate, wood, glass plate, other plate materials, cans, bottles, other cylindrical objects, boxes, containers, etc. The type thereof is not limited, but it is suitable for wide plate-shaped base materials and sheet-shaped base materials.

[0024] In the example of FIG. 1, a total of four recording heads 1a to 1d are mounted on the carriage 4, and a row of two recording heads arranged at intervals in the recording width direction intersecting the transport direction as shown is shifted in the transport direction and arranged in two rows, and is arranged in a staggered manner with a part of each recording width overlapping in the recording width direction, so that a wide image can be recorded. And four mist suction boxes 21a to 21d corresponding to each of the arranged plurality of recording heads 1a to 1d are arranged along each row of the recording heads.

[0025] FIG. 2 is a bottom view of the carriage for explaining the positional relationship between the nozzle surface and the mist suction port. When the carriage 4 is viewed from the bottom, each of the recording heads 1a to 1d has nozzle surfaces 11a to 11d in which a plurality of nozzles for discharging ink are arranged in a predetermined direction (recording width direction), and the ink is discharged from the nozzles onto the recording medium 7 according to the image data to perform image recording. In the inkjet recording apparatus 100 for recording a color image, although not particularly shown in the example of FIG. 1, usually, recording heads 1 for discharging inks of four colors, namely black (K), cyan (C), magenta (M), and yellow (Y), are arranged. Further, if necessary, recording heads for discharging special inks such as white (W) and clear (CL) required for the required image formation can be further mounted, the recording heads corresponding to the colors not required can be omitted, and various liquid agents can be discharged instead of the color inks. Further, as the recording head, one that can discharge one color of ink with one recording head may be used, or one that can discharge two or more different types of ink with one recording head (recording head corresponding to multicolor ink) can also be used.

[0026] The ink used for image recording can be arbitrarily selected without particular limitation, such as active ray curable ink, aqueous ink, solvent-based ink, etc. Although not particularly shown in the example of FIG. 1, when the ink used for image recording is active ray curable ink, the carriage 4 can be further equipped with an appropriate active ray irradiation device, and the active ray can be irradiated as needed after the image recording operation. For the active ray irradiation device, an appropriate one can be selected according to the properties of the active ray curable ink used, such as an ultraviolet irradiation device or an electron beam device. Also, for the lamp used in the ultraviolet irradiation device, an appropriate type such as mercury, metal halide, LED, etc. can be selected. When the ink used for image recording is solvent-based ink, aqueous ink, etc., various heat drying devices can be appropriately arranged instead.

[0027] As shown in FIG. 2, mist suction ports 211a to 211d of mist suction boxes 21a to 21d are arranged corresponding to nozzle surfaces 11a to 11d of recording heads 1a to 1d, respectively. Thus, nozzle surfaces 11a to 11d and mist suction ports 211a to 211d can be arranged close to each other, and ink mist generated from recording heads 1a to 1d can be surely sucked and recovered from the corresponding mist suction ports 211a to 211d. In this way, instead of arranging a mist suction mechanism having a wide single mist suction port in the recording width direction for a plurality of recording heads, by arranging one mist suction port for one nozzle surface, even when the recording heads are staggeredly arranged, the mist suction port can be arranged at a position as close as possible to the recording heads while avoiding the staggeredly arranged recording heads, and ink mist can be recovered more surely.

[0028] In FIG. 2, the recording head 1b is disposed at a position separated from the recording head 1a by a first distance T1 in the recording width direction. The recording head 1c is disposed at a position separated from the recording head 1a by a second distance T2 in the conveyance direction, and the recording head 1d is disposed at a position separated from the recording head 1c by the first distance T1 in the recording width direction. Further, the recording heads 1c and 1d are arranged in a staggered manner with respect to the recording heads 1a and 1b by being shifted in the recording width direction. In FIG. 2, the recording head 1c is disposed corresponding to the region between the recording heads 1a and 1b. Further, the mist suction port 211a is disposed at a position separated from the recording head 1a by a third distance T3 in the conveyance direction, and the mist suction port 211b is disposed at a position separated from the mist suction port 211a by a distance corresponding to the first distance T1 in the recording width direction and separated from the recording head 1b by the third distance T3 in the conveyance direction. Further, the mist suction port 211c is disposed at a position separated from the mist suction port 211a by a distance corresponding to the second distance T2 in the conveyance direction and separated from the recording head 1c by a fourth distance T4 in the conveyance direction. Furthermore, the mist suction port 211d is disposed at a position separated from the mist suction port 211b by a distance corresponding to the second distance T2 in the conveyance direction and separated from the recording head 1d by a fourth distance T4 in the conveyance direction.

[0029] The first distance T1 is set to an appropriate distance such that, while taking into account the arrangement intervals of a plurality of nozzles disposed on the nozzle surfaces 11a to 11d of the recording heads 1a to 1d so as to achieve a predetermined recording width, the ends of each of the recording heads 1a and 1b and the ends of each of the recording heads 1c and 1d are partially overlapped in the recording width direction as necessary.

[0030] The second distance T2 is set in consideration of the arrangement relationship between the recording heads 1a to 1d and the mist suction boxes 21a to 21d, and also in consideration of the arrangement relationship when an additional active light irradiation device is disposed on the carriage 4.

[0031] The third distance T3 and the fourth distance T4 are appropriately set in consideration of the occurrence state of ink mist, the conveyance environment, and the like. 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 the present embodiment, the third distance T3 and the fourth distance T4 are set to be substantially the same distance. By setting the third distance T3 and the fourth distance T4 to be substantially the same distance, the variation in the distances between the nozzle surfaces 11a to 11d and the mist suction ports 211a to 211d can be reduced, and the suction state of the ink mist can be maintained relatively uniformly, 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 be substantially the same distance. Considering various factors such as the device shape, the arrangement relationship of each member, the performance of the ink used, the generation state of the airflow around the nozzle surface, and the performance of the recording head, the third distance T3 and the fourth distance T4 can also be set to appropriate different distances.

[0032] Also, the relationship among the above-mentioned first distance T1 to fourth distance T4 shows one of the embodiments, and it can be deformed within the range where appropriate image recording can be performed and an appropriate ink mist suction effect can be achieved. For example, it is also assumed that the distance between the nozzle surface 11a and the nozzle surface 11b and the distance between the nozzle surface 11c and the nozzle surface 11d are made different as necessary, and it is also assumed that the distance between the nozzle surface 11a and the mist suction port 211a and the distances between each of the nozzle surfaces 11b to 11d and each of the mist suction ports 211b to 211d are made different.

[0033] Also, as shown in FIG. 1, the group of the mist suction boxes 21a and 21b and the group of the mist suction boxes 21c and 21d are connected to and coupled with the aggregating members 22a and 22b that each extend in the recording width direction, thereby constituting the mist suction mechanism 2a and the mist suction mechanism 2b. The air containing the ink mist sucked by each of the mist suction boxes 21a and 21b is aggregated in the aggregating member 22a and exhausted from the exhaust port 221a. Further, the air containing the ink mist sucked by each of the mist suction boxes 21c and 21d is aggregated in the aggregating member 22b and exhausted from the exhaust port 221b. And for each of the mist suction mechanisms 2a and 2b, correspondingly, an ink recovery mechanism 3a and an ink recovery mechanism 3b are mounted to recover the ink that has liquefied and accumulated in the mist suction mechanisms 2a and 2b and prevent the leakage of ink from each of the mist suction mechanisms 2a and 2b.

[0034] Note that the arrangement relationship and number of the recording head 1 and the mist suction mechanism 2 are not limited to this, and according to the shape of the recording medium 7, the size of the inkjet recording apparatus 100, the number of the recording heads 1, etc., the mist suction mechanism 2 having a configuration in which the mist suction boxes 21 are arranged can be appropriately selected. Also, the arrangement relationship of the mist suction mechanism 2 can be appropriately selected upstream or downstream in the conveyance direction with respect to the recording head 1. Further, the width of the opening of the mist suction port 211 can be set as appropriate, but from the viewpoint of surely recovering the 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. Also, from the viewpoint of preventing the adhesion of the ink mist 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. Also, the shape of the aggregating member 22 is not limited to that shown in FIG. 1, and an appropriate shape can be selected.

[0035] Also, in the example of FIG. 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 controlled by a control means (not shown). As the carriage moving means 5, a linear motion means such as a ball screw or a linear motor can be adopted. Further, on the exhaust port 221 side of the converging member 22 in the recording width direction of the inkjet recording apparatus 100, an exhaust means 6 is arranged, which is composed of an exhaust chamber 61 having a plurality of connection ports 62a and 62b corresponding to the exhaust ports 221a and 221b, and an exhaust blower 63 for exhausting the air in the exhaust chamber 61. Also, in the direction opposite to the location where the exhaust means 6 is arranged in the recording width direction, a retracted position 8 for performing cleaning of the recording heads 1a to 1d and the bottom surface of the carriage 4, and storage of the recording heads 1a to 1d is arranged.

[0036] Also, with respect to the recording width direction of the inkjet recording apparatus 100, the exhaust means 6 is arranged on the side where the exhaust ports 221a and 221b are arranged. The exhaust means 6 is composed of an exhaust chamber 61 in which connection ports 62a and 62b arranged for connecting to the exhaust ports 221a and 221b are arranged in the number corresponding to the exhaust ports (two places in the example of FIG. 1) to gather the air containing ink mist flowing in from each of the exhaust ports 221a and 221b, and an exhaust blower 63 for exhausting the air in 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 gathered in the exhaust chamber 61 and discharged from the exhaust chamber 61 by the drive of the exhaust blower 63.

[0037] Here, another configuration example of the exhaust means 6 will be described. FIG. 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 exhaust means 6 in the inkjet recording apparatus 100 of FIG. 3, ventilation paths 64a and 64b are provided between each of the connection ports 62a and 62b and the exhaust chamber 61. According to this configuration, the air containing ink mist flowing 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 and reaches the exhaust chamber 61 and is gathered. Here, a configuration is assumed in which the length L1 of the ventilation path 64a and the length L2 of the ventilation path 64b are made substantially the same. By adopting such a configuration, the distances from the exhaust blower 63 to the exhaust port 221a and to the exhaust port 221b are made substantially constant, and the homogeneity of the exhaust air pressure applied to each of the exhaust ports 221a and 221b by the exhaust blower 63 is improved. Thereby, the exhaust air pressure applied to each of the mist suction mechanisms 2a and 2b can be stabilized, and the stability of the ink mist suction operation can be improved. Note that the shape, material, etc. of the ventilation path 64 are not particularly limited, and appropriate members such as pipes, ducts, and hoses can be selected.

[0038] Here, the switching between connection and disconnection between the exhaust means 6 and the mist suction mechanism 2 will be described. As described above, it is necessary to aggregate the air containing the ink mist discharged from the mist discharge ports 212a to 212d of each of the plurality of mist suction boxes 21a to 21d by 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 by some method. However, in the inkjet recording apparatus 100 of the present embodiment, in order to perform maintenance and storage of the recording heads 1a to 1d, it is necessary to move the carriage 4 for retracting the recording heads 1a to 1d from above the conveyance means of the recording medium 7. For this reason, when the exhaust ports 221a and 221b are connected to the exhaust means 6 by piping, when the carriage 4 is moved, it will be moved to the connecting piping, which may lead to complexity of the device configuration and damage to the piping due to the movement. Therefore, in the inkjet recording apparatus 100 according to the present embodiment, the exhaust port 221 is connected to the exhaust means 6 when performing image recording, and when storing or maintaining the recording head 1 when not performing image recording, the exhaust ports 221a and 221b and the exhaust means 6 are configured to be disconnected.

[0039] FIG. 4 is a schematic diagram showing the switching status of connection and disconnection between the exhaust means 6 and the mist suction mechanism 2. When performing image recording, by driving the carriage moving means 5 to move the carriage 4 in the direction of the exhaust means 6 as shown in FIG. 4(a), the carriage 4 is moved above the recording medium 7 and the exhaust ports 221a and 221b are connected to the connection ports 62a and 62b of the exhaust chamber 61 of the exhaust means 6 (connected state). At this time, even when there are a plurality of aggregation members 22 corresponding to a plurality of mist suction mechanisms 2 as in this inkjet recording apparatus 100, by providing a plurality of connection ports 62 corresponding to each of the plurality of exhaust ports 221, all the exhaust ports 221 can be connected to the exhaust means 6 by moving the carriage 4 once. Further, by driving the carriage moving means 5 to move the carriage 4 in the direction of the retracted position 8 as shown in FIG. 4(b), the connection between the exhaust port 221 and the exhaust means 6 is disconnected. Similarly, when there are a plurality of exhaust ports 221, all of these are disconnected from the exhaust means 6 (disconnected state). In this way, by adopting a configuration in which the connection / disconnection state between the exhaust port 221 and the connection port 62 is switched according to the movement of the carriage 4 to the image recording position and the movement to the retracted position 8, the configuration is such that the exhaust port 221 and the exhaust means 6 are connected during image recording when ink mist is generated. Thus, the piping of the apparatus can be significantly reduced with a simple apparatus configuration, and the movement of the piping can be omitted to reduce the possibility of damage to the piping. In the example of this embodiment, an example in which connection and disconnection are performed in the recording width direction substantially orthogonal to the conveyance direction is used, but other configurations can also be assumed, such as a configuration in which the carriage 4 is moved in the direction of conveying the base material to perform connection and disconnection according to the shape of the recording medium 7 and the apparatus shape.

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

[0041] FIG. 5 is a perspective view of a mist suction mechanism equipped with a mist suction mechanism and an ink recovery mechanism. Further, FIG. 6 is a cross-sectional view of the mist suction mechanism and the ink recovery mechanism. In FIGS. 5 and 6, the mist suction mechanism 2a and the ink recovery mechanism 3a are referred to.

[0042] The configuration of the mist suction mechanism 2a in the present embodiment will be described in detail. Each of the mist suction boxes 21a and 21b has a flow-through portion 223 for allowing the ink mist sucked from the mist suction port 211a to flow. Then, each of the mist suction boxes 21a and 21d of the mist suction mechanism 2a is connected to and joined to an aggregation member 22a extending in the recording width direction via a mist discharge port 212a and a mist discharge port 212b to constitute one mist suction mechanism 2a. The air containing the ink mist sucked by each of the mist suction boxes 21a and 21b of the mist suction mechanism 2a is aggregated in the aggregation member 22a through the flow-through portion 223 in the mist suction box and exhausted from the exhaust port 221a.

[0043] Here, the aggregation member 22a of the mist suction mechanism 2a will be described. In order to collect the ink mist recovered from the mist suction port 211a of the mist suction box 21a and the mist suction port 211b of the mist suction box 21b, means for discharging the air containing the ink mist from each of the mist discharge ports 212a and 212b corresponding to the mist suction box 21a and the mist suction box 21b is required. For this purpose, if it is necessary to connect exhaust pipes to each of the mist discharge ports 212a and 212b, when connecting the pipes one by one corresponding to each of the plurality of mist suction boxes, the amount of pipes will be large, which will affect productivity and maintainability. Therefore, in the inkjet recording apparatus 100 of the present embodiment, a plurality of mist suction boxes 21 arranged in the recording width direction are connected by an aggregation member 22 extending in the recording width direction and integrated as one mist suction mechanism 2, so that the pipes for exhausting from the mist suction box 21 can be significantly reduced. Furthermore, since the mist suction box 21 and the aggregation member 22 are mounted on the same carriage 4 and both move integrally, long pipes are not required for connecting the mist suction box 21 and the aggregation member 22. This configuration is particularly effective in the case of a large inkjet recording apparatus 100 in which a large number of recording heads 1 are arranged and a corresponding large number of mist suction boxes 21 are also required to be arranged. Also, as in the present embodiment, by separating the aggregation member 22 according to the arrangement position of the recording head 1 in the conveyance direction, the variation in the distance from the mist suction port 211 to the aggregation member 22 can be reduced, and the suction force applied to each of the mist suction ports 211 can be maintained relatively uniformly, making it possible to reliably suck the ink mist.

[0044] Hereinafter, the internal structure of the mist suction mechanism 2 and the internal structure of the ink recovery mechanism 3 will be described in detail with reference to FIG. 6 and the like.

[0045] First, the internal structure of the mist suction mechanism 2 will be described. Inside the mist suction mechanism 2a, a space is formed that communicates from each of the mist suction ports 211a and 211b via the flow-through part 223 to the exhaust port 221a of the aggregating member 22a through the mist discharge ports 212a and 212b. Also, inside the flow-through part 223 of each of the mist suction boxes 21a and 21b, a liquefaction promotion part for promoting the liquefaction of the ink mist is arranged. In this example, the baffle plate 213, which is a plurality of plate-shaped members for bringing the ink mist passing through the flow-through part 223 into contact, is arranged at a position where it is easy to come into contact with the ink mist as the liquefaction promotion part. And near the mist suction port 211a of the mist suction box 21a, an ink storage part 214 for storing the ink obtained by the ink mist coming into contact with the baffle plate 213 and liquefying is arranged. Also, inside the aggregating member 22a, an ink storage part 222 for storing the ink liquefied in the process of the air containing the ink mist flowing through the space inside the aggregating member 22a is arranged at an appropriate position. The internal configuration of the mist suction mechanism 2b is the same as that of the mist suction mechanism 2a.

[0046] Here, a modified example of the mist suction mechanism will be described. FIG. 7 is a cross-sectional view showing a modified example of the mist suction mechanism. FIG. 7 shows a mist suction mechanism 1002 which is a modified example in which four mist suction boxes 1021a to 1021d are connected to one aggregating member 1022. From the viewpoint of performing stable suction of ink mist, it is effective to maintain the suction force applied to each of the mist suction ports 1211a to 1211d relatively uniformly. However, for the plurality of mist suction boxes 1021a to 1021d mounted on the aggregating member 1022, the suction force applied to the mist suction port 1211 corresponding to the mist discharge port 1212 closer to the exhaust port 1221 connected to the exhaust means 6 exhausted by the exhaust blower 63 is weaker than that of the mist suction port 1211 corresponding to the mist discharge port 1212 farther from this distance. Thus, in the example shown in FIG. 7, regarding the opening width W of the mist discharge port 1212, the opening width W1 of the mist discharge port 1212a closest to the exhaust port 1221 is made the smallest, and in the order of the opening width W2 of the mist discharge port 1212b, the opening width W3 of the mist discharge port 1212c, and the opening width W4 of the mist discharge port 1212d, it is set to increase as the distance from the exhaust port 1221 increases. Thereby, the suction force of the mist suction port 1211a corresponding to the mist discharge port 1212a close to the exhaust port 1221 is relatively weakened, and the suction forces of the mist suction ports 1211b to 1211d corresponding to the mist discharge ports 1212b to 1212d far from the exhaust port 1221 are relatively strengthened. By adopting such a configuration, the non-uniformity of the suction force due to the difference in the distance between the exhaust port 1221 and the mist discharge ports 1212a to 1212d can be eliminated, and the suction force applied to each of the mist suction ports 1211a to 1211d can be maintained relatively uniformly. Note that such a configuration can also be realized by other means such as adjusting the opening area by connecting mesh members with different opening ratios to the mist discharge ports 1212a to 1212d in addition to changing the opening width W of the mist discharge ports 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 includes the first ink flow path 312, the second ink flow path 313, the ink discharge port 314, and the ink flow control member 32, and is connected to an ink recovery mechanism 3a in which an ink recovery port 311 corresponding to each of the mist suction boxes 21a and 21b and the aggregation member 22a is arranged. In the ink storage portions 214 of each of the mist suction boxes 21a and 21b and the ink storage portion 222 of the aggregation member 22, the ink recovery port 311 of the ink recovery mechanism 3a for recovering the ink accumulated in the ink storage portion 214 and the ink storage portion 222 is located. The arrangement position of the ink storage portion 222 can be set at an appropriate position. In the examples of FIGS. 5 and 6, the ink storage portion 222 and the corresponding ink recovery port 311 are arranged on the opposite side of the exhaust port 221a. However, considering that the ink liquefied from the ink mist moving the aggregation member 22a tends to gather near the exhaust port 221a in the direction in which the ink mist flows, a configuration in which the ink storage portion 222 and the corresponding ink recovery port 311 are arranged near the exhaust port 221a is also assumed.

[0048] On the side opposite to the ink recovery port 311 of the first ink flow path 312, ink flow control members 32 for controlling the flow of ink recovered from the ink recovery port 311 and flowing through the first ink flow path 312 and the second ink flow path 313 are arranged in a number corresponding to each of the plurality of ink recovery ports 311. The ink flow control member 32 can appropriately apply a check valve that permits the flow of ink from the ink recovery port 311 toward the ink discharge port 314 and prevents the backflow of ink due to the flow of ink in the opposite direction. The ink flow control member 32 in the example of the present embodiment includes, in order from the side of the ink recovery port 311, an inflow opening 321 into which the ink recovered from the ink recovery port 311 flows, a closing member 322 for blocking the flow of ink within the ink flow control member 32, an elastic member 323 having elasticity for pressing the closing member 322 against the inflow opening 321, and an outflow opening 324 for discharging the ink within the ink flow control member 32. The closing member 322 can adopt an appropriate valve body, spherical body, etc., as long as it is a member having a shape that can appropriately close / open the inflow opening 321. In the example of FIG. 6, a spherical member is adopted. Also, the elastic member 323 can adopt an appropriate member as long as it can press the closing member 322 toward the inflow opening 321, and the arrangement relationship between the closing member 322 and the elastic member 323 can also be appropriately selected. In the example of FIG. 6, a spring body is adopted. The elastic force of the elastic member 323 is preferably set to an appropriate value such that the opening / closing state of the inflow opening 321 by the closing member 322 is appropriately changed according to the negative pressure situation in the first ink flow path 312.

[0049] In addition, each of a plurality of outflow openings 324 corresponding to each of the plurality of ink flow control members 32 is connected to a second ink flow path 313, and is gathered into one second ink flow path 313 via a manifold or the like (not shown), thereby forming a space up to the ink discharge port 314. The ink discharge port 314 is connected to a waste ink tank 34 that stores the ink recovered from the ink recovery port 311. Further, a negative pressure applying means 33 is connected to the space from the ink recovery port 311 to the ink discharge port 314 via the first ink flow path 312 and the second ink flow path 313 to apply a negative pressure to the space, so as to cause the ink to flow from the ink recovery port 311 to the ink discharge port 314. As the negative pressure applying means 33, an appropriate method such as a negative pressure pump can be selected. In the example of FIG. 6, the negative pressure applying means 33 is configured to apply a negative pressure to the first ink flow path 312 via the waste ink tank 34, but other configurations may be used as long as a negative pressure can be applied to the first ink flow path 312.

[0050] Based on the above description, the operations of ink mist suction by the mist suction mechanism 2 and ink recovery by the ink recovery mechanism 3 will be sequentially described below.

[0051] First, the operation of ink mist suction by the mist suction mechanism 2 will be described.

[0052] When the inkjet recording apparatus 100 performs image recording, the carriage 4 is moved above the recording medium 7 by driving of the carriage moving means 5, and the exhaust ports 221a of the aggregating member 22a and the exhaust ports 221b of the aggregating member 22b are connected to the connection ports 62a and 62b of the exhaust chamber 61 (FIG. 4(a)). As a result, a space communicating from each of the mist suction ports 211a to 211d of the mist suction boxes 21a to 21d to the exhaust chamber 61 is formed, and by driving the exhaust blower 63 connected to the exhaust chamber 61, an air flow from each of the mist suction ports 211a to 211d to the exhaust chamber 61 is formed in the space, enabling the surrounding air to be sucked from the mist suction ports 211a to 211d.

[0053] After starting image recording by ejecting ink from the nozzles disposed on the nozzle surfaces 11a to 11d of the recording heads 1a to 1d onto the recording medium 7, ink mist accompanying ink ejection by each of the plurality of recording heads 1a to 1d disposed on the carriage 4 is generated in the space around the bottom surface of the carriage 4 including the periphery of the nozzle surfaces 11a to 11d. Air around the carriage 4 containing ink mist is sucked from each of the mist suction ports 211a to 211d of the mist suction boxes 21a to 21d disposed corresponding to each of the nozzle surfaces 11a to 11d of the plurality of recording heads 1a to 1d to suck the ink mist. Since the mist suction ports 211a to 211d corresponding to each are disposed in the vicinity of each of the nozzle surfaces 11a to 11d, it is possible to more reliably suck the ink mist generated by the ink ejected from the nozzles of each of the nozzle surfaces 11a to 11d.

[0054] A part of the ink mist recovered from each of the mist suction ports 211a to 211d is promoted to liquefy in the process of contacting the baffle plates 213 disposed inside the mist suction boxes 21a to 21d, and the liquefied ink is stored in the ink storage portion 214 at any time. Further, the air containing the ink mist that has not been liquefied is discharged from each of the mist discharge ports 212a to 212d while passing through the space inside the mist suction boxes 21a to 21d. The air containing the ink mist exhausted from each of the mist discharge ports 212a to 212d is aggregated in the aggregating members 22a and 22b. The ink mist may be promoted to liquefy due to the relationship of the ambient temperature and contact with the inner walls of the aggregating members 22a and 22b. Thus, the ink liquefied in the aggregating members 22a and 22b is stored in the ink storage portion 222 at any time. Then, the air containing the ink mist that has not been liquefied is exhausted into the exhaust chamber 61 from the exhaust ports 221a and 221b, and the air containing the ink mist from the mist suction mechanisms 2a and 2b is aggregated and finally exhausted from the exhaust chamber 61 by the exhaust blower 63.

[0055] Next, the operation of ink recovery by the ink recovery mechanism 3 will be described.

[0056] As described above, each of the plurality of ink recovery ports 311 of the ink recovery mechanism 3 disposed in the ink storage portion 214 or the ink storage portion 222 of the mist suction mechanism 2 contacts the liquid surface of the ink stored in the ink storage portion 214 or the ink storage portion 222, and due to the action of the negative pressure applied in the first ink flow path 312 by the negative pressure applying means 33, ink is sucked 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 from the inflow opening 321 of the ink flow control member 32 corresponding to each of the ink recovery ports 311, flows out from the outflow opening 324, and flows into the second ink flow path 313 gathered by a branch pipe or the like as described above, and is discharged from the ink discharge port 314 to the waste ink tank 34.

[0057] Here, the operation of the ink flow control member 32 will be described with reference to FIG. 8.

[0058] In the case where there are a plurality of ink recovery ports 311 as in the example of the present embodiment and they are finally gathered into one second ink flow path 313 by a branch pipe or the like, if there is no member such as the ink flow control member 32 and all the ink recovery ports 311 and the first ink flow path 312 are always in communication via the second ink flow path 313, when a part of the plurality of ink recovery ports 311 is open to the atmosphere without contacting the ink, as a result, all of the plurality of first ink flow paths 312 are connected to the atmosphere via the second ink flow path 313. Even if the negative pressure applying means 33 is driven, an appropriate negative pressure cannot be generated in all of the first ink flow paths 312, and a phenomenon may occur in which ink cannot be sucked up from the ink recovery ports 311 in contact with the ink. If ink cannot be properly recovered from the ink storage portion 214 and the ink storage portion 222, the overflowing ink may leak from the mist suction mechanism 2a and the mist suction mechanism 2b, which may inhibit the stable mist suction operation.

[0059] Therefore, in the ink recovery mechanisms 3a and 3b in the present embodiment, among the plurality of ink recovery ports 311, for the ink flow control member 32 corresponding to the ink recovery port 311 in contact with ink, its inflow opening 321 is kept open without being blocked by the blocking member 322, and the ink is allowed to flow toward the outflow opening 324 side. On the other hand, among the plurality of ink recovery ports 311, for the ink flow control member 32 corresponding to the ink recovery port 311 that is not in contact with ink and is open to the atmosphere, its inflow opening 321 is blocked by the blocking member 322 and kept closed, so that the section of the first ink flow path 312 on the second ink flow path side of the outflow opening 324 from the ink flow control member 32 is not in contact with the atmosphere. Implementing these processes using an electronic valve, a sensor, etc. would result in a large-scale device configuration and could lead to an increase in manufacturing costs, etc. Therefore, it is effective to implement these processes with a simple configuration as in the present embodiment. Hereinafter, the configuration in the present embodiment will be further described.

[0060] FIG. 8 is a schematic diagram for explaining the operation of switching the opening and closing of the blocking member of the ink flow control member. The elastic force of the elastic member 323 is such that when a negative pressure is applied to the section of the first ink flow path 312 on the outflow opening 324 side of the ink flow control member 32 and the inflow opening 321 of the ink flow control member 32 from the ink recovery port 311 is not filled with ink and is open to the atmosphere, the blocking member 322 is pressed toward the inflow opening 321 to close the inflow opening 321 to a closed state. On the other hand, when the inflow opening 321 of the ink flow control member 32 from the ink recovery port 311 is filled with ink and is not open to the atmosphere, the blocking member 322 is pressed toward the outflow opening side by the negative pressure applied from the negative pressure applying means 33 to open the inflow opening 321 to an open state, and it is set to an appropriate elastic force that enables this. As a result, when the ink recovery port 311 is open to the atmosphere, the inflow opening 321 can be maintained in a closed state by the blocking member 322, and only the ink recovery port 311 and the first ink flow path 312 that are not filled with ink are disconnected from the second ink flow path 313, avoiding the phenomenon that the other ink recovery ports 311 filled with ink and the first ink flow path 312 are connected to the atmosphere and a negative pressure cannot be applied.

[0061] On the other hand, when ink accumulates in the ink storage section 214 or the 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 blocked from the atmosphere. As a result, the negative pressure in the space from the ink recovery port 311 to the inflow opening 321 of the ink flow control member 32 increases, and the blocking member 322 is pressed toward the outflow opening 324 side and moves toward the outflow opening 324 side, so that the inflow opening 321 is opened. Then, when the passage of the ink is completed and the ink recovery port 311 is opened to the atmosphere again, the space from the ink recovery port 311 to the inflow 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 such a configuration, the ink recovery mechanism 3 in the present embodiment can reliably recover the ink accumulated in the ink storage section 214 or the ink storage section 222 with a simple configuration.

[0063] With the above configuration, it has been possible to realize the inkjet recording apparatus 100 that can perform stable image recording while reliably recovering ink mist.

[0064] In the above description, for the sake of easy understanding of the present invention, the description of known technical matters has been appropriately omitted.

[0065] The present invention can be implemented in various embodiments and modifications without departing from the broad spirit and scope of the present invention. Further, the above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is indicated not by the embodiments but by the claims. And various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

Explanation of Reference Numerals

[0066] 100 Inkjet recording apparatus 1a to 1d Recording head 11a to 11d Nozzle surface 2a to 2b Mist suction mechanism 21a to 21d Mist suction box 211a to 211d Mist suction port 212a to 212d Mist discharge port 213 Baffle plate (liquefaction promotion part) 214 Ink storage part 22a to 22b Aggregation member 221a to 221b Exhaust port 222 Ink storage part 223 Flow-through part 3a to 3b Ink recovery mechanism 311 Ink recovery port 312 First ink flow path 313 Second ink flow path 314 Ink discharge port 32 Ink flow control member 321 Inflow opening 322 Blocking member 323 Elastic member 324 Outflow opening 33 Negative pressure applying means 34 Waste ink tank 4 Carriage 5 Carriage moving means 6 Exhaust means 61 Exhaust chamber 62a to 62b Connection port 63 Exhaust blower 64a to 64b Ventilation path 7 Recording medium 8 Retraction position 1002 Mist suction mechanism (modified example) 1021a to d Mist suction box (modified example) 1211a to d Mist suction port (modified example) 1212a to d Mist discharge port (modified example) 1022 Aggregation member (modified example) 1221 Exhaust port (modified example)

Claims

1. An inkjet recording apparatus comprising a plurality of recording heads in which a plurality of nozzles for ejecting ink are arranged, and performing a recording operation by ejecting ink from the plurality of recording heads onto a recording medium that moves relatively in a first direction with respect to the plurality of recording heads, a plurality of mist suction units provided corresponding to each of the plurality of recording heads, each having a mist suction port for sucking ink mist generated from the recording head and a mist discharge port for discharging the sucked ink mist, a 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 exhausting air including the ink mist in the space, and being an aggregating member for aggregating air including the ink mist flowing in from the plurality of mist discharge ports in the space and exhausting the air from the exhaust port, a carriage for mounting the plurality of mist suction units and the aggregating member, an exhaust chamber having a connection port for connecting to the exhaust port, and exhausting air in the space of the aggregating member from the exhaust port in a state where the exhaust port is connected to the connection port, and switching means for switching 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 relatively moving the carriage in the second direction with respect to the exhaust chamber. The inkjet recording apparatus is characterized by having the above.

2. The inkjet recording apparatus according to claim 1, further comprising 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 by the carriage moving means.

3. The inkjet recording apparatus further has another recording head arranged at a position different from the plurality of recording heads with respect to the first direction, another mist suction unit corresponding to the another recording head, and another aggregating member corresponding to the another mist suction unit, and the carriage is further mounted with the another mist suction unit and the another aggregating member, the exhaust chamber has a plurality of connection ports corresponding to each of the plurality of exhaust ports of each of the aggregating member and the another aggregating 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 simultaneously connected; The second state 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 switches between the first state and the second state by relatively moving the carriage in the second direction with respect to the exhaust chamber. The inkjet recording apparatus according to claim 1 or claim 2.

4. 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 through from the plurality of exhaust ports, and the lengths of the plurality of ventilation paths are substantially the same. The inkjet recording apparatus according to claim 3.

5. The carriage further mounts the plurality of recording heads. The inkjet recording apparatus according to claim 1 or claim 2.

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

7. The opening amount of one of the mist discharge ports among the plurality of mist suction portions connected to the aggregating member is smaller than the opening amount of another mist discharge port disposed at a position farther from the one mist discharge port with respect to the exhaust port. The inkjet recording apparatus according to claim 1 or claim 2.

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