Inkjet recording apparatus

Abstract

To provide an inkjet recording apparatus including an ink mist suction mechanism capable of reliably collecting ink remaining in the mist suction mechanism and performing stable mist suction 【Solution means】 A mist suction mechanism having a recording head and an ink storage unit for storing ink obtained by liquefying the ink mist sucked from the mist suction port; an ink recovery port for recovering the ink stored in the ink storage unit; an ink flow control member that switches between a first state that allows the ink to flow in the recovery direction and a second state that blocks the ink by the opening and closing operation of the closing member; and a negative pressure applying means for applying a negative pressure to the closing member. When the section from the ink recovery port to the ink flow control member is filled with ink, the ink flow control member sets the closing member to an open state by negative pressure to be in the first state. When the section from the ink recovery port to the ink flow control member is not filled with ink, the ink flow control member sets the closing member to a closed state to be in the second state regardless of the negative pressure

Description

Technical Field

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

Background Art

[0002] Conventionally, an inkjet recording apparatus that performs printing by an inkjet method in which a plurality of nozzles for discharging ink are arranged and an ink is discharged while relatively moving a recording head and a recording medium in a conveyance direction intersecting a direction in which a recording width extends to perform image recording with a predetermined recording width has been widely used.

[0003] In such an inkjet recording apparatus, ink mist, which is fine mist-like ink, may be generated when ink is discharged 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 a single-pass inkjet recording apparatus 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 discharged at high speed and in large quantities, so the generation of ink mist may occur more significantly.

[0005] Therefore, various inkjet recording apparatuses provided with a mechanism for collecting generated ink mist have been proposed (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] By the way, in the mist suction mechanism, a phenomenon may occur in which the sucked mist becomes liquid and remains as the mist is sucked. Therefore, it is effective to mount a mechanism for recovering such remaining ink in the mist suction mechanism. In this regard, Patent Document 3 discloses a mechanism for sucking up ink by a tube (derivation part) branched into a plurality of (mist) suction containers arranged in the conveyance direction and collecting it in a collection container.

[0008] However, when sucking up and recovering the remaining ink with a tube, if the inside of the tube is connected to the atmosphere, a phenomenon may occur in which the pump connected to the tube leaks with the air at atmospheric pressure and cannot suck ink from the mist suction mechanism. In particular, when recovering ink from a plurality of mist suction mechanisms using branched tubes, if some of the tubes leak, the negative pressure cannot be maintained in the other tubes, and as a result, a phenomenon may occur in which ink cannot be recovered from all the mist suction mechanisms, which may hinder the stable continuous operation of mist suction.

[0009] The present invention has been made in view of the above problems, and provides an inkjet recording apparatus including an ink mist suction mechanism that solves the above problems, reliably recovers the ink remaining in the mist suction mechanism, and can perform stable mist suction.

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, in an inkjet recording apparatus that performs recording by discharging ink from a recording head to a recording medium that flows relative to a recording head in which a plurality of nozzles for discharging ink are arranged over a predetermined width, a mist suction mechanism having a mist suction port for sucking ink mist generated by ink discharge from the recording head, and an ink storage unit for storing ink obtained by liquefying the ink mist sucked from the mist suction port; and an ink recovery mechanism for recovering the ink stored in the ink storage unit. The ink recovery mechanism includes an ink recovery port for recovering the ink stored in the ink storage unit, and an ink recovery member having an ink flow path for flowing the ink recovered from the ink recovery port in the recovery direction; an ink flow control member that switches between a first state that enables the ink to flow in the recovery direction and a second state that blocks the flow of the ink in the recovery direction by an opening / closing operation of a closing member disposed at a predetermined position of the ink flow path; an ink discharge portion where the ink that has flowed in the ink flow path of the ink recovery member in the recovery direction is discharged; and a negative pressure applying means for applying a negative pressure to open the closing member from a closed state to an open state. The ink flow control member is characterized in that when the section from the ink recovery port to the ink flow control member in the ink flow path is filled with ink, the closing member is set to the open state by negative pressure to set the ink flow path to the first state, and when the section from the ink recovery port to the ink flow control member in the ink flow path is not filled with ink, the closing member is set to the closed state regardless of the negative pressure to set the ink flow path to the second state.

[0012] Also, the ink flow control member increases the negative pressure in the ink flow path to the first state by blocking the ink flow path from the atmosphere when the ink flow path is filled with ink in part or in whole of the section from the ink recovery port in the ink flow path to the ink flow control member. It is characterized in that the second state is set when the section is connected to the atmosphere.

[0013] Also, a plurality of the mist suction mechanisms are arranged, and an ink recovery mechanism is arranged corresponding to each of the plurality of the mist suction mechanisms. It is characterized in that each of the ink discharge parts in the plurality of the mist suction mechanisms is connected and communicates with each other.

[0014] Also, the mist suction mechanism includes a mist discharge port for discharging the ink mist sucked from the mist suction port. The inkjet recording apparatus further includes an aggregating member that is connected to each of the mist discharge ports of the plurality of the mist suction mechanisms, has a space communicating with each of the plurality of the mist discharge ports, and aggregates and exhausts the air flowing in from each of the plurality of the mist discharge ports. It is characterized in that the aggregating member is further provided with the ink recovery mechanism for recovering the ink obtained by liquefying the ink mist floating in the space.

[0015] Also, the mist suction mechanism is provided with a liquefaction promoting part for promoting the liquefaction of the sucked ink mist, and the ink liquefied by the liquefaction promoting part is stored in the ink storage part.

[0016] Also, the liquefaction promoting part is a plate-like member that contacts the ink mist sucked from the mist suction port.

[0017] Further, the ink flow control member has an elastic member having elasticity for pressing the closing member against an inflow opening for allowing the ink recovered from the ink recovery port to flow in. The ink flow control member is characterized in that the closing member is switched to the first state by being pressed by the ink in a direction opposite to the pressing direction by the elastic member.

[0018] Further, in the second state, the ink flow control member is characterized in that it prevents the ink from flowing in the ink flow path in a direction opposite to the recovery direction.

Effects of the Invention

[0019] According to the present invention, with the above configuration, the above problems are solved, and an ink mist suction mechanism capable of reliably recovering the ink remaining in the mist suction mechanism and performing stable mist suction can be provided, thereby providing an inkjet recording apparatus.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0021] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is a schematic perspective view showing the configuration of an inkjet recording apparatus according to an embodiment of the present invention, schematically showing a configuration example of the apparatus. An inkjet recording apparatus 100 according to an embodiment of the present invention includes recording heads 1a to 1d, mist suction mechanisms 2a, 2b, ink recovery mechanisms 3a, 3b, a carriage 4, carriage moving means 5, and exhaust means 6.

[0023] 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 a driving means, a conveyor, a roll-to-roll conveyor, a robot arm, etc. can be adopted.

[0024] 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 high-speed printing is performed 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.

[0025] 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 arranged with a shift in the conveyance direction as shown in the figure, and are arranged in a staggered manner with a shift in the recording width direction so that a part of each recording width overlaps, thereby enabling a wide image to 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 row of the recording heads.

[0026] 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 to 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 four colors of ink, 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, recording heads corresponding to colors 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 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) may be used.

[0027] The ink used for image recording can be arbitrarily selected without particular limitation, such as active light-curing 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 light-curing ink, the carriage 4 can be further equipped with an appropriate active light irradiation device, and the active light can be irradiated as needed at any time after the image recording operation. For the active light irradiation device, an appropriate one can be selected according to the properties of the active light-curing 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, aqueous ink, etc., various heat drying devices can be appropriately arranged instead.

[0028] 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. As a result, the nozzle surfaces 11a to 11d and the mist suction ports 211a to 211d can be arranged close 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 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.

[0029] 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.

[0030] The first distance T1 is set to an appropriate distance such that, while taking into account 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, 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.

[0031] 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 ray irradiation device is disposed on the carriage 4, etc.

[0032] 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 contribute to the simplification of the apparatus configuration while maintaining the ink mist suction state relatively uniformly. 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 shape of the apparatus, 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. The third distance T3 and the fourth distance T4 can also be set to appropriate different distances.

[0033] In addition, the relationship between the above first distance T1 to the 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 obtained. 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 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 the mist suction ports 211b to 211d are made different.

[0034] 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 aggregation members 22a and 22b that extend in the recording width direction, respectively, 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 aggregation member 22a and exhausted from the exhaust port 221a. Also, the air containing the ink mist sucked by each of the mist suction boxes 21c and 21d is aggregated in the aggregation member 22b and exhausted from the exhaust port 221b. And, corresponding to each of the mist suction mechanisms 2a and 2b, there are mounted 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 to prevent the leakage of ink from each of the mist suction mechanisms 2a and 2b.

[0035] 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, etc. 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. Also, 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 preferably set 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 aggregation member 22 is not limited to that shown in FIG. 1, and an appropriate shape can be selected.

[0036] 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 intensifying member 22 in the recording width direction of the inkjet recording apparatus 100, an exhaust means 6 constituted by 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 is arranged. 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.

[0037] 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 constituted by an exhaust chamber 61 in which connection ports 62a and 62b arranged for connecting to the exhaust ports 221a and 221b are arranged in a number corresponding to the exhaust ports (two locations in the example of FIG. 1) to collect 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 collected in the exhaust chamber 61 and discharged from the exhaust chamber 61 by the drive of the exhaust blower 63.

[0038] 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.

[0039] Here, the switching between connection and disconnection of 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 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 disconnected.

[0040] 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 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, so that 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.

[0041] 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.

[0042] 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.

[0043] 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 portion 223 for 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 an aggregation member 22a extending in the recording width direction via a mist discharge port 212a and a mist discharge port 212b and connected to form 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 portion 223 in the mist suction box and exhausted from the exhaust port 221a.

[0044] 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, if it is necessary to connect an exhaust pipe 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, the plurality of mist suction boxes 21 arranged in the recording width direction are connected by the aggregating member 22 extending in the recording width direction, and are grouped together 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, a long pipe is 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, making it possible to surely suck the ink mist.

[0045] 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.

[0046] 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 through the flow-through portion 223 to the exhaust port 221a of the aggregating member 22a via the mist discharge ports 212a and 212b. Also, inside the flow-through portion 223 of each 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-like 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 aggregating 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 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.

[0047] 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 suction force applied to 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 is weaker than that of the mist suction port 1211 corresponding to the mist discharge port 1212 closer to the exhaust port 1221. Therefore, 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. In addition, 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.

[0048] 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 the ink recovery mechanism 3a in which the ink recovery ports 311 corresponding to each of the mist suction boxes 21a and 21b and the aggregating member 22a are 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 aggregating 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 moving the aggregating 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.

[0049] 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 the 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 the ink from the ink recovery port 311 toward the ink discharge port 314 and prevents the backflow of the ink due to the flow of the 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 the 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.

[0050] In addition, a second ink flow path 313 is connected to each of a plurality of outflow openings 324 corresponding to each of the plurality of ink flow control members 32, and the second ink flow paths 313 are aggregated into one via a branch pipe (not shown) or the like, 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.

[0051] 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.

[0052] First, the operation of ink mist suction by the mist suction mechanism 2 will be described.

[0053] 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, so that the surrounding air can be sucked from the mist suction ports 211a to 211d.

[0054] 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 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 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.

[0055] 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 unit 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 unit 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.

[0056] Next, the operation of ink recovery by the ink recovery mechanism 3 will be described.

[0057] 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 comes into contact with the liquid surface of the ink stored in the ink storage section 214 or the ink storage section 222, and is sucked and recovered from each of the ink recovery ports 311 by the action of the negative pressure applied in the first ink flow path 312 by the negative pressure applying means 33. 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 aggregated 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.

[0058] Here, the operation of the ink flow control member 32 will be described with reference to FIG. 8.

[0059] 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 aggregated 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 the ink cannot be sucked up from the ink recovery port 311 in contact with the ink. If the ink cannot be properly 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.

[0060] Therefore, in the ink recovery mechanisms 3a and 3b in this 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 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 the ink and is open to the atmosphere, the inflow opening 321 thereof is blocked by the blocking member 322 to be in a closed state, 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 this embodiment. Hereinafter, the configuration in this embodiment will be further described.

[0061] 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 ink flow path 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 open to the atmosphere without being filled with ink, the blocking member 322 is pressed toward the inflow opening 321 side to block the inflow opening 321 to be in 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, 2 Ink flow path 313 when a negative pressure is applied to the section of the ink flow path 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 open to the atmosphere without being filled with ink, the blocking member 322 is pressed toward the inflow opening 321 side to block the inflow opening 321 to be in 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, Side section when a negative pressure is applied to the section of the ink flow path 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 open to the atmosphere without being filled with ink, the blocking member 322 is pressed toward the inflow opening 321 side to block the inflow opening 321 to be in 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, Side section 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, Pressure in the space from the liquid surface in the first ink flow path to the inflow opening 321It is set to an appropriate elastic force that allows the closing member 322 to be pressed toward the outflow opening side to open the inflow opening 321. 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 closing member 322, and only the ink recovery port 311 that is not filled with ink and the first ink flow path 312 are disconnected from the second ink flow path 313, and it is possible to avoid the phenomenon that the ink recovery port 311 filled with other ink and the first ink flow path 312 are connected to the atmosphere and negative pressure cannot be applied.

[0062] 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 Pressure pressure in the space from the ink recovery port 311 to the inflow opening 321 of the ink flow control member 32 rises, so that the closing member 322 is pressed toward the outflow opening 324 side and moves toward the outflow opening 324 side, causing the inflow opening 321 to be in an open state. As a result, 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.

[0063] 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.

[0064] With the above configuration, it is possible to realize an inkjet recording apparatus 100 that can perform stable image recording while reliably recovering ink mist.

[0065] In the above description, for ease of understanding of the present invention, the description of known technical matters has been appropriately omitted.

[0066] 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 regarded as being within the scope of the present invention.

Explanation of Signs

[0067] 100 Inkjet recording apparatus 1a~1d Recording head 11a~11d Nozzle surface 2a~2b Mist suction mechanism 21a~21d Mist suction box 211a~211d Mist suction port 212a~212d Mist discharge port 213 Baffle plate (liquefaction promotion part) 214 Ink storage part 22a~22b Aggregation member 221a~221b Exhaust port 222 Ink storage part 223 Flow-through part 3a~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~62b Connection port 63 Exhaust Blower 64a - 64b Ventilation Path 7 Recorded Medium 8 Retraction Position 1002 Mist Suction Mechanism (Variant Example) 1021a - d Mist Suction Box (Variant Example) 1211a - d Mist Suction Port (Variant Example) 1212a - d Mist Discharge Port (Variant Example) 1022 Aggregation Member (Variant Example) 1221 Exhaust Port (Variant Example)

Claims

1. In an inkjet recording apparatus that performs recording by discharging ink from a recording head onto a recording medium that flows relative to the recording head in which a plurality of nozzles for discharging ink are arranged over a predetermined width, a mist suction mechanism having a mist suction port for sucking ink mist generated by ink discharge from the recording head, and an ink storage unit for storing ink obtained by liquefying the ink mist sucked from the mist suction port; an ink recovery mechanism for recovering the ink stored in the ink storage unit; The ink recovery mechanism includes: an ink recovery member having an ink recovery port for recovering the ink stored in the ink storage unit, and an ink flow path for flowing the ink recovered from the ink recovery port in a recovery direction; an ink flow control member including a blocking member disposed at a predetermined position in the ink flow path, the ink flow path being in a first state that blocks the flow of ink in the recovery direction when the blocking member is in a closed state, and the ink flow path being in a second state that allows the flow of ink in the recovery direction when the blocking member is in an open state; an ink discharge portion where the ink flowing in the ink flow path of the ink recovery member in the recovery direction is discharged; negative pressure applying means for applying a negative pressure for discharging the ink from the ink flow path to the ink discharge portion to a first section of the ink flow path from the ink discharge portion to the blocking member of the ink flow control member; The ink flow control member includes an elastic member having elasticity for pressing the blocking member in a direction opposite to the recovery direction, the elastic member keeping the blocking member in the closed state and the ink flow path in the first state with no ink filled in a second section of the ink flow path from the ink recovery port to the blocking member of the ink flow control member, and being able to change the blocking member from the closed state to the open state according to the pressure in the second section with ink filled in the second section, thereby changing the ink flow path to the second state, and pressing the blocking member in the opposite direction with an elastic force that enables this. An inkjet recording apparatus characterized by this.

2. A plurality of the mist suction mechanisms are arranged, and an ink recovery mechanism is arranged corresponding to each of the plurality of mist suction mechanisms. The inkjet recording apparatus according to claim 1, characterized in that each of the ink discharge portions in the plurality of the mist suction mechanisms is connected and in communication with each other.

3. The mist suction mechanism includes a mist discharge port for discharging the ink mist sucked from the mist suction port, and the inkjet recording apparatus includes a space that is connected to each of the mist discharge ports of the plurality of the mist suction mechanisms and is in communication with each of the plurality of the mist discharge ports, and further includes an aggregating member for aggregating and exhausting the air flowing in from each of the plurality of the mist discharge ports. The inkjet recording apparatus according to claim 2, characterized in that an ink recovery mechanism for recovering ink obtained by liquefying the ink mist floating in the space is further disposed in the aggregating member.

4. The inkjet recording apparatus according to claim 1 or claim 2, characterized in that a liquefaction promoting portion for promoting liquefaction of the sucked ink mist is disposed in the mist suction mechanism, and the ink liquefied by the liquefaction promoting portion is stored in the ink storage portion.

5. The inkjet recording apparatus according to claim 4, characterized in that the liquefaction promoting portion is a plate-like member that contacts the ink mist sucked from the mist suction port.

6. The inkjet recording apparatus according to claim 1 or claim 2, characterized in that in the first state, the ink flow control member prevents the ink from flowing in the opposite direction in the ink flow path.

Images