Inkjet recording apparatus

Abstract

To provide an inkjet recording apparatus including an ink mist suction mechanism capable of surely sucking ink mist generated from each of a plurality of recording heads arranged with positions shifted in a first direction and a second direction intersecting the first direction **Solution**: A first recording head, a second recording head disposed at a first distance from the first recording head in the first direction, a third recording head disposed between the first recording head and the second recording head and at a second distance from the first recording head in the second direction, and first to third mist suction ports are provided. The first mist suction port is at a third distance in the second direction from the first recording head, the second mist suction port is at a distance corresponding to the first distance in the first direction from the first mist suction port and at a third distance in the second direction from the second recording head, and the third mist suction port is at a distance corresponding to the second distance from the first mist suction port in the second direction and at a fourth distance in the second direction from the third recording head, and they are arranged at positions separated from each other

Description

Technical Field

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

Background Art

[0002] Conventionally, using a recording head in which a plurality of nozzles for ejecting ink are arranged to perform image recording with a predetermined recording width, 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 printing by an inkjet method for recording an image. Inkjet recording apparatuses are widely used.

[0003] In such an inkjet recording apparatus, when ink is ejected from the nozzles, ink mist, which is fine atomized ink, may be generated. 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 in which image recording can be completed during one execution of the relative movement between the recording head and the recording medium, generally, since the image recording speed is 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 of the disclosed ones have a mist suction mechanism with 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.

[0008] However, in the case of an inkjet recording apparatus in which the arrangement positions of the recording heads are shifted with respect to the conveyance direction, such as when a plurality of recording heads are arranged in a staggered manner as described above, in the case of a conventional mist suction mechanism having a single wide horizontally long continuous mist suction port, the distance from the recording head to the mist suction mechanism becomes non-uniform, and there is a risk that reliable mist suction cannot be performed.

[0009] The present invention has been made in view of the above problems, solves the above problems, and provides an inkjet recording apparatus including an ink mist suction mechanism capable of reliably sucking ink mist generated from each of a plurality of recording heads arranged with positions shifted in a first direction and a second direction intersecting the first direction. [Means for Solving the Problems]

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

[0011] That is, in the present invention, there are a first recording head, a second recording head, and a third recording head, which are provided with a plurality of nozzles for discharging ink and record an image with a predetermined width in a first direction. The second recording head is arranged at a first distance from the first recording head in the first direction, and the third recording head is further arranged at a position corresponding to the middle between the first recording head and the second recording head in the first direction and at a second distance from the first recording head in a second direction intersecting the first direction. In an inkjet recording apparatus that discharges ink from the first recording head, the second recording head, and the third recording head to perform image recording on a recording medium that relatively moves in the second direction with respect to the recording unit, a first suction unit including a first mist suction port for sucking ink mist generated by ink discharge from the first recording head, a first flow-through portion for allowing the ink mist sucked from the first mist suction port to flow through, and a first mist discharge port for discharging the ink mist from the first flow-through portion; a second suction unit including a second mist suction port for sucking ink mist generated by ink discharge from the second recording head, a second flow-through portion for allowing the ink mist sucked from the second mist suction port to flow through, and a second mist discharge port for discharging the ink mist from the second flow-through portion; and a first mist suction mechanism including a first aggregation member having a first space extending in the first direction and communicating with the first mist discharge port of the first suction unit and the second mist discharge port of the second suction unit, a third suction unit including a third mist suction port for sucking ink mist generated by ink discharge from the third recording head, a third flow-through portion for allowing the ink mist sucked from the third mist suction port to flow through, and a third mist discharge port for discharging the ink mist from the third flow-through portion; and a second mist suction mechanism including a second aggregation member having a second space extending in the first direction and communicating with the third mist discharge port of the third suction unit, Exhaust means for discharging air containing ink mist that has flowed into the first space of the first aggregating member and air containing ink mist that has flowed into the second space of the second aggregating member, The first mist suction port is disposed at a position separated from the first recording head by a third distance in the second direction, and the second mist suction port is disposed at a position separated from the first mist suction port by a distance corresponding to the first distance in the first direction and separated from the second recording head by the third distance in the second direction. The third mist suction port is disposed at a position separated from the first mist suction port by a distance corresponding to the second distance with respect to the second direction and separated from the third recording head by a fourth distance in the second direction.

[0012] In the present invention, the third distance and the fourth distance are shorter than the second distance.

[0013] In the present invention, the third distance and the fourth distance are substantially the same distance.

[0014] In the present invention, the first mist suction port has a width wider than the predetermined width of the first recording head.

[0015] In the present invention, the exhaust means includes an exhaust chamber having a first connection port connected to the first aggregating member and a second connection port connected to the second aggregating member, and an exhaust blower connected to the exhaust chamber for exhausting air in the exhaust chamber. The exhaust means, by driving the exhaust blower, aggregates and discharges air containing ink mist flowing into the first space from the first mist discharge port and air containing ink mist flowing into the second space from the second mist discharge port into the exhaust chamber.

[0016] Further, in the present invention, the first connection port is connected to the exhaust chamber via a first ventilation path for allowing air containing ink mist flowing in from the first space to pass through, and the second connection port is connected to the exhaust chamber via a second ventilation path for allowing air containing ink mist flowing in from the second space to pass through, and the lengths of the first ventilation path and the second ventilation path are substantially the same.

[0017] Further, in the present invention, a fourth recording head disposed at a first distance from the third recording head in the first direction, a fourth mist suction mechanism provided corresponding to the fourth recording head, having a fourth mist suction port for sucking ink mist generated by ink ejection by the fourth recording head, and a fourth mist discharge port for discharging the ink mist sucked from the fourth mist suction port, is further disposed, the fourth mist suction port is disposed at a position separated from the fourth recording head by a fourth distance in the second direction, the fourth mist discharge port is connected to the second aggregating member and communicates with the second space, so that air containing ink mist discharged from the fourth mist suction port flows into the second space.

[0018] Further, in the present invention, the exhaust means includes an exhaust chamber having a first connection port connected to the first aggregating member and a second connection port connected to the second aggregating member, and an exhaust blower connected to the exhaust chamber for exhausting air in the exhaust chamber, the exhaust means, by driving the exhaust blower, aggregates and discharges air containing ink mist flowing into the first space from each of the first mist discharge port and the third mist discharge port, and air containing ink mist flowing into the second space from each of the second mist discharge port and the fourth mist discharge port into the exhaust chamber.

[0019] Further, in the present invention, in the first aggregating member, the first mist discharge port is disposed at a position closer to the exhaust means than the second mist discharge port, and the opening amount of the first mist discharge port is smaller than the opening amount of the second mist discharge port.

Advantages of the Invention

[0020] According to the present invention, with the above configuration, the above problems can be solved, and an inkjet recording apparatus provided with an ink mist suction mechanism capable of reliably sucking ink mist generated from each of a plurality of recording heads arranged with positions shifted in a first direction and a second direction intersecting the first direction can be provided.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0022] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0023] 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, mist suction mechanisms 2b, ink recovery mechanisms 3a, ink recovery mechanisms 3b, a carriage 4, carriage moving means 5, and exhaust means 6.

[0024] At least one of the recording head 1 and the recording medium 7 is movable in the transport direction by 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 connected to driving means, a conveyor, a roll-to-roll conveyor, a robot arm, etc. can be adopted.

[0025] Note that this inkjet recording apparatus 100 is applicable to both a multi-pass method (also called a serial head method) and a single-pass method (also called a line head method). It is suitable for the single-pass method in which a large amount of ink mist tends to be generated in a short time by performing high-speed printing. 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 a wide plate-shaped base material or a sheet-shaped base material.

[0026] In the example of FIG. 1, a total of four recording heads 1a to 1d are mounted on the carriage 4, and two rows of recording heads arranged at intervals in the recording width direction intersecting the conveyance direction are displaced in the conveyance direction and arranged in two rows. Further, they are arranged in a staggered pattern with a part of each recording width shifted 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 plurality of arranged recording heads 1a to 1d are arranged along each of the rows of the recording heads.

[0027] FIG. 2 is a bottom view of the carriage for explaining the arrangement 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, a recording head 1 for discharging ink of four colors, black (K), cyan (C), magenta (M), and yellow (Y), is arranged. Further, if necessary, a recording head for discharging special inks such as white (W) and clear (CL) required for the required image formation can be further mounted, the recording head corresponding to the color not required can be omitted, and various liquid agents can be discharged instead of the color ink. Further, as the recording head, one that can discharge one color of ink 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.

[0028] The ink used for image recording can be arbitrarily selected without particular limitation, such as active ray-curable ink, water-based 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 at any time 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, an electron beam device, etc. 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, water-based ink, etc., various heat drying devices can be appropriately arranged instead.

[0029] As shown in FIG. 2, a configuration is adopted in which the mist suction ports 211a to 211d of the mist suction boxes 21a to 21d are arranged corresponding to the nozzle surfaces 11a to 11d of the recording heads 1a to 1d, respectively. Thereby, the nozzle surfaces 11a to 11d and the mist suction ports 211a to 211d can be arranged in proximity to each other, and the ink mist generated from the 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 adopting a configuration in which one mist suction port is arranged for one nozzle surface, even when the recording heads are staggeredly arranged, the mist suction port can be arranged as close as possible to the recording heads while avoiding the staggeredly arranged recording heads, and the ink mist can be recovered more surely.

[0030] 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.

[0031] The first distance T1 is set to an appropriate distance such that the end portions of the recording heads 1a and 1b and the end portions of the recording heads 1c and 1d are partially overlapped in the recording width direction as necessary, while considering the arrangement intervals of the 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.

[0032] 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 the arrangement relationship when an additional active light irradiation device is disposed on the carriage 4, etc.

[0033] 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, it is possible to reduce the variation in the distances between the nozzle surfaces 11a to 11d and the mist suction ports 211a to 211d, and to maintain the ink mist suction state relatively uniformly, 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 be substantially the same distance, and various factors such as the device shape, the arrangement relationship of each member, the performance of the ink used, the generation state of the air flow around the nozzle surface, and the performance of the recording head are considered, and the third distance T3 and the fourth distance T4 can be set to appropriate different distances.

[0034] Further, the relationship among the above-described first distance T1 to fourth distance T4 shows one of the embodiments, and can be deformed within a range in which 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.

[0035] 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 an aggregating member 22a and an aggregating member 22b that each extend in the recording width direction, thereby constituting a mist suction mechanism 2a and a mist suction mechanism 2b. The air containing the ink mist sucked by each of the mist suction boxes 21a and 21b is aggregated by 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 by the aggregating member 22b and exhausted from the exhaust port 221b. And, corresponding to each of the mist suction mechanisms 2a and 2b, an ink recovery mechanism 3a and an ink recovery mechanism 3b for recovering the ink liquefied and accumulated in the mist suction mechanisms 2a and 2b and preventing the leakage of ink from each of the mist suction mechanisms 2a and 2b are mounted.

[0036] Note that the arrangement relationship and the number of the recording head 1 and the mist suction mechanism 2 are not limited to this, and the mist suction mechanism 2 having a configuration in which the mist suction box 21 is arranged can be appropriately selected according to the shape of the recording medium 7, the size of the inkjet recording apparatus 100, the number of the recording heads 1, and the like. 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 reliably 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.

[0037] 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 driving 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 aggregating 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.

[0038] Also, regarding 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 exhausted from the exhaust chamber 61 by driving the exhaust blower 63.

[0039] 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 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 uniformity 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.

[0040] 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 collect 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 collecting 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 maintain and store 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 and the exhaust means 6 are connected 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 and the exhaust means 6 are connected when image recording is performed, and when the recording heads 1 are stored or maintained without performing image recording, the exhaust ports 221a and 221b and the exhaust means 6 are configured to be disconnected.

[0041] 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 (connection 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 (non-connection state). In this way, by adopting a configuration in which the connection and 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 exhaust port 221 and the exhaust means 6 are connected during image recording when ink mist is generated. With a simple device configuration, the piping of the device can be significantly reduced, 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. However, depending on the shape of the recording medium 7 and the device shape, other configurations such as a configuration in which the carriage 4 is moved in the direction of conveying the base material to perform connection and disconnection are also conceivable.

[0042] 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.

[0043] FIG. 5 is a perspective view of a mist suction mechanism equipped with a mist suction mechanism and an ink recovery mechanism. 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.

[0044] 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 portion 223 for allowing the ink mist sucked from the mist suction port 211a to flow. And each of the mist suction box 21a and the mist suction box 21d is connected to and joined to an aggregating 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 aggregating member 22a through the flow portion 223 in the mist suction box and exhausted from the exhaust port 221a.

[0045] Here, the aggregating 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, it is necessary to connect exhaust pipes to each of the mist discharge ports 212a and 212b. However, when connecting the pipes one by one corresponding to each of the plurality of mist suction boxes, a large amount of pipes will be generated, which will affect productivity and maintainability. Therefore, in the inkjet recording apparatus 100 of the present embodiment, the plurality of mist suction boxes 21 arranged in the recording width direction are connected by an aggregating member 22 extending in the recording width direction, and are grouped as one mist suction mechanism 2, so that the pipes for exhausting from the mist suction box 21 can be significantly reduced. Further, since the mist suction box 21 and the aggregating 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 aggregating 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 aggregating 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 aggregating member 22 can be reduced, and the suction force applied to each of the mist suction ports 211 can be maintained relatively uniformly, so that the ink mist can be reliably sucked.

[0046] 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.

[0047] First, the internal structure of the mist suction mechanism 2 will be described. The inside of the mist suction mechanism 2a forms a space that communicates from each of the mist suction ports 211a and 211b via the flow-through portion 223 to the exhaust port 221a of the aggregation member 22a through the mist discharge ports 212a and 212b. Also, inside each of the flow-through portions 223 of the mist suction boxes 21a and 21b, a liquefaction promotion portion 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 portion 223 into contact, is arranged at a position where it is easy to come into contact with the ink mist as the liquefaction promotion portion. And near the mist suction port 211a of the mist suction box 21a, an ink storage portion 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 aggregation member 22a, an ink storage portion 222 for storing the ink liquefied in the process of the air containing the ink mist flowing through the space inside the aggregation 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.

[0048] 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 aggregation 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 aggregation member 1022, the mist suction port 1211 corresponding to the mist discharge port 1212 which is farther from the exhaust port 1221 connected to the exhaust means 6 exhausted by the exhaust blower 63 has a weaker suction force applied to the mist suction port 1211 than the mist suction port 1211 corresponding to the mist discharge port 1212 closer to the exhaust port 1221. 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 becomes farther. 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.

[0049] 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. The ink recovery ports 311 of the ink recovery mechanism 3a for recovering the ink accumulated in the ink storage portions 214 of the mist suction boxes 21a and 21b and the ink storage portion 222 of the aggregation member 22 are located in the ink storage portions 214 and 222. 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 side opposite to the exhaust port 221a. However, considering that the liquefied ink of the ink mist that moves 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.

[0050] On the side opposite to the ink recovery port 311 of the first ink flow path 312, a plurality of 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 blocks the backflow of ink due to the flow of ink in the opposite direction. The ink flow control member 32 in the example of this 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, sphere, 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 one as long as it is a member that 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.

[0051] 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 the second ink flow paths 313 are aggregated into one via a branch pipe 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 for applying a negative pressure 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 cause the ink to flow from the ink recovery port 311 to the ink discharge port 314 is connected. 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.

[0052] 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.

[0053] First, the operation of ink mist suction by the mist suction mechanism 2 will be described.

[0054] When the inkjet recording apparatus 100 performs image recording, the carriage 4 is moved above the recording medium 7 by driving 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.

[0055] 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 is generated in the space around the bottom surface of the carriage 4 including the periphery of the nozzle surfaces 11a to 11d due to the ink ejection by each of the plurality of recording heads 1a to 1d disposed on the carriage 4. Air around the carriage 4 containing the 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 of the nozzle surfaces 11a to 11d are disposed in the vicinity of each of the nozzle surfaces 11a to 11d, the ink mist generated by the ink ejected from the nozzles of each of the nozzle surfaces 11a to 11d can be more reliably sucked.

[0056] 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 plate 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. Also, 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 internal space of 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, etc. Thus, the ink liquefied in the aggregating members 22a and 22b is stored in the ink storage portion 222 at any time. And 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.

[0057] Next, the operation of ink recovery by the ink recovery mechanism 3 will be described.

[0058] As described above, each of the plurality of ink recovery ports 311 of the ink recovery mechanism 3 disposed in the ink storage section 214 or the ink storage section 222 of the mist suction mechanism 2 contacts the liquid surface of the ink stored in the ink storage section 214 or the ink storage section 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.

[0059] Here, the operation of the ink flow control member 32 will be described with reference to FIG. 8.

[0060] In the case of a configuration in which 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 appropriately recovered from the ink storage section 214 and the ink storage section 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.

[0061] 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 the ink, the inflow opening 321 thereof is left 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 the ink and is open to the atmosphere, the inflow opening 321 thereof is blocked by the blocking member 322 and 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, or the like would result in a large-scale device configuration and could lead to an increase in manufacturing costs. 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.

[0062] 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 is not filled with ink and is open to the atmosphere from the ink recovery port 311, the blocking member 322 is pressed toward the inflow opening 321 to close the inflow opening 321 in a closed state. 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 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 in an open state. The elastic force is set appropriately to enable 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.

[0063] On the other hand, when ink accumulates in the ink storage unit 214 or the ink storage unit 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 closing 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 in an open state. Thus, 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.

[0064] With such a configuration, the ink recovery mechanism 3 in the present embodiment can reliably recover the ink accumulated in the ink storage unit 214 or the ink storage unit 222 with a simple configuration.

[0065] 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.

[0066] In the above description, for the sake of easy understanding of the present invention, the description of known technical matters has been appropriately omitted.

[0067] 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 by the claims rather than the embodiments. 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

[0068] 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 part 322 Blocking member 323 Elastic member 324 Outflow opening part 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 having a first recording head, a second recording head, and a third recording head, each having a plurality of nozzles for ejecting ink and recording an image of a predetermined width in a first direction, wherein the second recording head is disposed at a first distance from the first recording head in the first direction, and the third recording head is disposed at a position corresponding to a position between the first recording head and the second recording head in the first direction and at a second distance from the first recording head in a second direction intersecting the first direction, and ejecting ink from the first recording head, the second recording head, and the third recording head onto a recording medium that moves relatively in the second direction with respect to the recording unit to perform image recording. A first suction unit including a first mist suction port formed in a width corresponding to the predetermined width with respect to the first direction for sucking ink mist generated by ink ejection from the first recording head, a first flow-through portion having a first internal space for allowing the ink mist sucked from the first mist suction port to flow through, and a first mist discharge port for discharging the ink mist from the first internal space of the first flow-through portion; a second suction unit including a second mist suction port formed in a width corresponding to the predetermined width with respect to the first direction for sucking ink mist generated by ink ejection from the second recording head, a second flow-through portion having a second internal space for allowing the ink mist sucked from the second mist suction port to flow through, and a second mist discharge port for discharging the ink mist from the second internal space of the second flow-through portion; and an aggregation member in which the first suction unit and the second suction unit are separately disposed at a predetermined interval in the first direction, and which communicates with the first internal space and the second internal space through the first mist discharge port of the first suction unit and the second mist discharge port of the second suction unit, and forms a first aggregation space for aggregating the ink mist discharged from the first mist discharge port and the second mist discharge port. A third mist suction port formed with a width corresponding to the predetermined width with respect to the first direction for sucking ink mist generated by ink ejection by the third recording head, a third flow portion having a third internal space formed for the ink mist sucked from the third mist suction port to flow through, and a third mist discharge port for discharging the ink mist from the third internal space of the third flow portion. A second mist suction mechanism comprising a third suction portion; and a second aggregation member in which a second aggregation space is formed that communicates with the third internal space via the third mist discharge port of the third suction portion and aggregates the ink mist discharged from the third mist discharge port. Exhaust means for discharging air containing ink mist that has flowed into the first aggregation space of the first aggregation member and air containing ink mist that has flowed into the second aggregation space of the second aggregation member. having The exhaust means further applies a suction force for sucking ink mist to the first mist suction port, the second mist suction port, and the third mist suction port through the first internal space, the second internal space, and the third internal space, which are spaces independent of each other. The first mist suction port is disposed at a position separated from the first recording head by a third distance in the second direction. The second mist suction port is disposed at a position separated from the first mist suction port by a distance corresponding to the first distance in the first direction and separated from the second recording head by the third distance in the second direction. The third mist suction port is disposed at a position separated from the first mist suction port by a distance corresponding to the second distance with respect to the second direction and separated from the third recording head by a fourth distance in the second direction. An inkjet recording apparatus characterized by this.

2. The inkjet recording apparatus according to claim 1, characterized in that the third distance and the fourth distance are shorter than the second distance.

3. The inkjet recording apparatus according to claim 1 or claim 2, characterized in that the third distance and the fourth distance are substantially the same distance.

4. The inkjet recording apparatus according to claim 1 or claim 2, characterized in that the first mist suction port has a width wider than the predetermined width of the first recording head.

5. The exhaust means includes an exhaust chamber having a first connection port connected to the first aggregating member and a second connection port connected to the second aggregating member, and an exhaust blower connected to the exhaust chamber for exhausting the air in the exhaust chamber. The exhaust means, by driving the exhaust blower, aggregates and discharges the air containing ink mist flowing from the first mist discharge port into the first aggregating space and the air containing ink mist flowing from the second mist discharge port into the second aggregating space into the exhaust chamber. The inkjet recording apparatus according to claim 1 or claim 2, characterized in that.

6. The first connection port is connected to the exhaust chamber via a first ventilation path for allowing the air containing ink mist flowing in from the first aggregating space to pass through, and the second connection port is connected to the exhaust chamber via a second ventilation path for allowing the air containing ink mist flowing in from the second aggregating space to pass through. The inkjet recording apparatus according to claim 5, characterized in that the lengths of the first ventilation path and the second ventilation path are substantially the same.

7. A fourth recording head disposed at a first distance from the third recording head in the first direction; A fourth suction unit further including a fourth mist suction port provided corresponding to the fourth recording head for sucking ink mist generated by ink ejection from the fourth recording head, a fourth flow-through portion having a fourth internal space for the ink mist sucked from the fourth mist suction port to flow through, and a fourth mist discharge port for discharging the ink mist sucked from the fourth mist suction port. The third suction unit and the fourth suction unit are separately arranged at a predetermined interval in the first direction with respect to the second aggregating member. The fourth mist suction port is disposed at a position separated by a fourth distance from the fourth recording head in the second direction. The fourth internal space communicates with the second aggregating space via the fourth mist discharge port, and the ink mist discharged from the fourth mist suction port flows into the second aggregating space. The inkjet recording apparatus according to claim 1 or claim 2, characterized in that.

8. The exhaust means includes an exhaust chamber having a first connection port connected to the first aggregation member and a second connection port connected to the second aggregation member, and an exhaust blower connected to the exhaust chamber for exhausting the air in the exhaust chamber. The inkjet recording apparatus according to claim 7, wherein the exhaust means, by driving the exhaust blower, aggregates and discharges the air containing ink mist flowing into the first aggregation space from each of the first mist discharge port and the third mist discharge port, and the air containing ink mist flowing into the second aggregation space from each of the second mist discharge port and the fourth mist discharge port into the exhaust chamber.

9. In the first aggregation member, the first mist discharge port is disposed at a position closer to the exhaust means than the second mist discharge port, and the opening amount of the first mist discharge port is smaller than the opening amount of the second mist discharge port. The inkjet recording apparatus according to claim 1 or claim 2.

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