Liquid droplet discharge unit, liquid droplet discharge device, and liquid droplet discharge system

Abstract

To provide a liquid droplet discharge unit which can achieve downsizing of a liquid droplet discharge device and improvement of the quality of images, and to provide the liquid droplet discharge device and a liquid droplet discharge system.SOLUTION: A liquid droplet discharge unit 100 includes: a liquid droplet discharge device 200 which discharges liquid droplets form each nozzle N of nozzle arrays Nl arranged on a nozzle surface; and an attachment plate 110 including an opening 111 which is a through hole to which the liquid droplet discharge device 200 is attached. The liquid droplet discharge device 200 includes: a positioning part P which contacts with a positioned part 112 of the attachment plate 110; and a force application part E which applies a force from the positioning part P to the positioned part 112.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present invention relates to a droplet ejection unit, a droplet ejection device, and a droplet ejection system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a droplet ejection device that ejects liquid from a droplet ejection head onto a recording surface of a recording medium at appropriate timing based on image data, thereby recording an image on the recording surface.

[0003] Furthermore, for example, Patent Document 1 describes a configuration in which a force applying unit is provided in the droplet ejection device, and the droplet ejection head is pressed against a positioning position, thereby attaching the droplet ejection head to the droplet ejection device with high precision. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-155880 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if a force application unit is provided on the device body to which the droplet ejection device is attached, the space required for the force application unit may lead to an increase in the size of the device body. On the other hand, if the droplet ejection head is not positioned with high precision by the force application unit, the droplet ejection head may become misaligned, resulting in a deterioration in image quality.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a droplet discharge unit, a droplet discharge device, and a droplet discharge system that are capable of suppressing deterioration in image quality while also miniaturizing the device. [Means for solving the problem]

[0007] In order to solve the above problems, the invention described in claim 1 is as follows: a droplet ejection device that ejects droplets from each nozzle of a nozzle array arranged on a nozzle surface; a mounting plate having an opening that is a through hole to which the droplet ejection device is attached, The droplet ejection device includes a positioning portion that contacts a positioned portion of the mounting plate; and a force applying portion that applies a force from the positioning portion to the positioned portion.

[0008] The invention described in claim 2 is the droplet discharge unit described in claim 1, The force applying portion comes into contact with the positioned portion so as to apply a force in the nozzle row direction and / or in a transport direction perpendicular to the nozzle row direction.

[0009] The invention described in claim 3 is the droplet discharge unit described in claim 1, a fixing unit that fixes the droplet ejection device to the mounting plate by applying a force from a height direction perpendicular to the nozzle surface; The droplet discharge device includes the force applying unit at a position farther from the fixing unit than the positioning unit, which is farthest in the nozzle row direction and in a transport direction perpendicular to the nozzle row direction.

[0010] The invention described in claim 4 is the droplet discharge unit described in claim 1, a fixing unit that fixes the droplet ejection device to the mounting plate by applying a force from a height direction perpendicular to the nozzle surface; The droplet discharge device includes the force applying unit at a position closer to the fixing unit than the positioning unit, which is farthest in the nozzle row direction and in a transport direction perpendicular to the nozzle row direction.

[0011] The invention described in claim 5 is the droplet discharge unit described in claim 1, the droplet ejection device includes at least one positioning unit on at least two surfaces, namely, a first surface parallel to the nozzle row and a second surface different from the first surface; When viewed from a height direction perpendicular to the nozzle surface, the positioning portion and the positioned portion are in point contact with each other, On the first surface, the positioning portion and the positioned portion come into point contact outside the longitudinal end of the nozzle row.

[0012] The invention described in claim 6 is the droplet discharge unit described in claim 1, The positioning portion and the force applying portion are provided between the mounting plate, the mounting surface of the droplet ejection device, and the nozzle surface.

[0013] The invention described in claim 7 is the droplet discharge unit described in claim 1, The mounting plate has a force applied portion of the mounting plate that contacts the force applying portion and the positioned portion on an upper surface thereof.

[0014] The invention described in claim 8 is the droplet discharge unit described in claim 1, At least a portion of the force application portion is made of a rigid material different from that of the positioning portion.

[0015] The invention described in claim 9 is the droplet discharge unit described in claim 1, The force application portion is made of the same rigid material as the positioning portion.

[0016] The invention described in claim 10 is the droplet discharge unit described in claim 1, The droplet discharge device includes the force application portion positioned inside the outer periphery of a mounting surface that is a contact surface with the mounting plate.

[0017] The invention described in claim 11 is the droplet discharge unit described in claim 1, The force applying portion is elastically or plastically deformable.

[0018] The invention described in claim 12 is A droplet ejection device that is attached to a mounting plate of a droplet ejection unit and ejects droplets from each nozzle of a nozzle array arranged on a nozzle surface, a positioning portion that contacts the mounting plate; and a force applying portion that applies a force to the positioning portion toward the mounting plate when the positioning portion is attached to the mounting plate.

[0019] The invention described in claim 13 is a droplet ejection system, a droplet ejection unit according to any one of claims 1 to 11; and a conveying unit that conveys the recording medium. [Effects of the Invention]

[0020] According to the present invention, it is possible to achieve both miniaturization of the device and high image quality. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a droplet ejection system. [Figure 2] FIG. 2 is a perspective view of a droplet discharge unit to which one droplet discharge device is attached. [Figure 3A] FIG. 1 is a perspective view of one droplet ejection device. [Figure 3B] FIG. 2 is a bottom view of one droplet ejection device. [Figure 4A] FIG. 2 is a bottom view of the droplet discharge unit. [Figure 4B] FIG. 2 is a bottom view of the droplet discharge unit. [Figure 5] FIG. 10 is a side cross-sectional view of a droplet discharge unit according to a modified example. [Figure 6] FIG. 10 is a perspective view of a droplet ejection device according to a modified example. [Figure 7] FIG. 10 is a bottom view of a droplet ejection device according to a modified example. [Figure 8] FIG. 10 is a perspective view of a mounting plate according to a modified example. [Figure 9] FIG. 10 is a top view of a droplet discharge unit according to a modified example. [Figure 10]FIG. 10 is a bottom view of a droplet ejection device according to a modified example. [Figure 11] FIG. 10 is a side view of a droplet ejection device according to a modified example. [Figure 12] FIG. 10 is a side view of a droplet discharge unit according to a modified example. [Figure 13] FIG. 10 is a bottom view of a droplet ejection device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described in detail below with reference to the drawings. Note that the embodiments described below are subject to various limitations that are technically preferable for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0023] (Inkjet recording device) 1 is a schematic perspective view showing an inkjet recording apparatus 10, which is an embodiment of a droplet ejection system according to this embodiment. The inkjet recording apparatus 10 includes a transport unit 11 and a head unit 100.

[0024] In the following description, the X direction, Y direction, and Z direction are the directions shown in Fig. 1. In addition, in the following description, the X direction, Y direction, and Z direction are also referred to as the width direction, conveyance direction, and height direction, respectively.

[0025] {Transportation section} The transport unit 11 includes two transport rollers 11a and a transport belt 11b. The transport unit 11 transports the recording medium S in a transport direction.

[0026] The transport rollers 11a, 11a rotate around a rotation axis extending in the width direction. The transport roller 11a supports the inside of the ring-shaped transport belt 11b. The recording medium S is placed on the transport surface of the transport belt 11b with the recording surface facing upward. When the transport roller 11a rotates in response to the operation of a transport motor (not shown), the transport belt 11b moves in a circular motion in the transport direction, transporting the recording medium S in the transport direction.

[0027] The transport unit 11 is not limited to the belt transport type configuration described above. For example, the transport unit 11 may be a drum transport type configuration. The drum transport type transport unit 11 includes a predetermined transport drum that rotates in the transport direction with the recording medium S in close contact with its outer circumferential surface.

[0028] {Recording Media} The recording medium S is, for example, a sheet of paper cut to a certain size. The recording medium S is fed onto a conveyor belt 11b from a paper feeder (not shown). Then, after images and characters are recorded on the recording medium S by the head unit 100, the recording medium S is discharged to a predetermined paper discharge section.

[0029] The recording medium S is not limited to sheets of paper. The recording medium S may be a long material such as rolled paper or continuous paper. The recording medium S may also be paper such as plain paper or coated paper, or fabric or sheet-like resin. In this way, various media can be used as the recording medium S as long as the ink that has landed on its surface can be fixed thereon.

[0030] As shown in Fig. 1, in an inkjet recording device 10, a plurality of head units 100 are arranged side by side from the upstream side to the downstream side in the transport direction of a recording medium S. Each head unit 100 records images and characters by ejecting ink of a respective color from a respective droplet ejection device 200 (see Fig. 2) onto the recording medium S transported by a transport unit 11. The ejection of ink from the droplet ejection device 200 by the head unit 100 is performed at appropriate timing based on image data.

[0031] 1 illustrates an example in which four head units 100 are arranged, each corresponding to one of four ink colors: yellow (Y), magenta (M), cyan (C), and black (K). However, the number of head units 100 provided in the inkjet recording apparatus 10 may be three or less, or five or more. Furthermore, a plurality of head units 100 that eject ink of the same color may be arranged.

[0032] {Head Unit} 2 shows one head unit 100. The head unit 100 includes a mounting plate 110, a fixing portion 120, and a droplet ejection device 200.

[0033] [Mounting plate] 2, the mounting plate 110 is a thin plate having a substantially rectangular shape extending in the width direction. The droplet ejection device 200 is attached to the mounting plate 110. The mounting plate 110 has a plurality of openings 111 formed therein, which are substantially rectangular through-holes.

[0034] <Opening> The opening 111 is a through hole that is slightly larger than the outer shape of the droplet ejection device 200 excluding the extension portion 201 described below when viewed from above. Making the opening 111 slightly larger than the outer shape of the droplet ejection device 200 prevents the droplet ejection device 200 from being unable to be attached to the mounting plate 110 in the event of a manufacturing error. A plurality of openings 111 are provided in the mounting plate 110 in a staggered pattern.

[0035] When attaching the droplet ejection device 200 to the mounting plate 110, the droplet ejection device 200 is inserted into the opening 111. Then, the droplet ejection device 200 is pressed so that a positioning portion P (see FIG. 3B), which will be described later, comes into point contact with the positioned portion 112 when viewed from a direction perpendicular to the nozzle surface. Then, a force applying portion E (see FIG. 3B), which will be described later, urges the positioning portion P toward the positioned portion 112. In this embodiment, the positioned portion 112 is the inner periphery of the opening 111.

[0036] As described above, the opening 111 is provided to be slightly larger than the outer shape of the droplet discharge device 200, but the inkjet recording device 10 of the present invention is provided with the positioning unit P and the force applying unit E. Therefore, the droplet discharge device 200 can be attached to the mounting plate 110 in a state where it is positioned with high precision, and the occurrence of positional deviation can be suppressed.

[0037] 2 shows an example of a mounting plate 110 having four openings 111 and capable of mounting four droplet ejection devices 200, but the present invention is not limited to this. In other words, the mounting plate 110 may be capable of mounting three or less, or five or more, droplet ejection devices 200.

[0038] However, it is preferable that the plurality of droplet ejection devices 200 can cover the entire width of the recording medium S. With this configuration, the inkjet recording device 10 is a single-pass type inkjet recording device that can form an image on the entire surface of the recording medium S without moving the head unit 100 in the width direction.

[0039] [Fixed part] The fixing portion 120 is a member that fixes the droplet ejection device 200 attached to the mounting plate 110 to the mounting plate 110. The fixing portion 120 fixes the droplet ejection device 200 to the mounting plate 110 by applying a downward pressing force to the extension portion 201, the lower surface of which abuts against the upper surface of the mounting plate 110.

[0040] The fixing portion 120 may be configured to apply a downward pressing force to the extending portion 201, thereby fixing the droplet ejection device 200 to the mounting plate 110. Therefore, the configuration of the fixing portion 120 is not particularly limited. The fixing portion 120 may be separate from the head unit 100. In this embodiment, the fixing portion 120 is made of a rigid portion having a screw shape, for example, as shown in FIG. 2.

[0041] However, it is not particularly preferable to configure the fixing portion 120 solely from a screw-shaped rigid portion. This is because, depending on the biasing force of the force applying portion E, the aligned droplet ejection device 200 may become misaligned due to the rotational torque generated by the rotation of the screw-shaped rigid portion. Therefore, it is more preferable to configure the fixing portion 120 to include an elastic portion made of an elastic body such as a spring, and to fix the droplet ejection device 200 to the mounting plate 110 by pressing the elastic portion with a rigid portion such as a screw.

[0042] [Droplet discharge device] Fig. 3A is a perspective view showing one droplet ejection device 200. Fig. 3B is a bottom view showing one droplet ejection device 200. In this embodiment, the droplet ejection device 200 is a head module made up of multiple inkjet heads 210. Using the droplet ejection device 200 as a head module can further improve the precision of the dot pitch during image recording.

[0043] As shown in FIGS. 3A and 3B, the droplet ejection device 200 includes a plurality of inkjet heads 210, a cover member 220, an attachment member 230, a mist intrusion prevention member 240, a positioning portion P, and a force applying portion E.

[0044] In the following, a head module composed of two inkjet heads 210 is exemplified, but the present invention is not limited to this. That is, a head module composed of three or more inkjet heads 210 may also be used. In addition, as shown in FIG. 3B, the following illustrates a case in which multiple inkjet heads 210 are arranged in a direction perpendicular to a nozzle row NL (described later), but the present invention is not limited to this.

[0045] [Inkjet head] The inkjet head 210 includes a nozzle plate 211, a first connector 212, and a second connector 213. The droplet ejection device 200 also includes a head chip (not shown) on which a drive mechanism for ejecting ink is formed.

[0046] <Nozzle plate> The nozzle plate 211 is a flat plate that is elongated in the width direction and disposed horizontally. As shown in Fig. 3B, a plurality of nozzles N are formed on the nozzle surface, which is the lower surface side of the nozzle plate 211.

[0047] The nozzles N are arranged in four nozzle rows NL parallel to each other in the width direction at a uniform nozzle pitch (hereinafter, x). The four nozzle rows NL are arranged at regular intervals in the transport direction. Of the four nozzle rows NL, the second nozzle row NL in the transport direction is offset by x / 2 from the first nozzle row NL. The third nozzle row NL is offset by x / 4 from the first nozzle row NL in the width direction. The fourth nozzle row NL is offset by x / 2 from the third nozzle row NL in the width direction. Therefore, the four nozzle rows NL of the nozzle plate 211 are sequentially offset by x / 4 from each other in the width direction. The inkjet head 210 can form dots with a dot pitch of x / 4. The number of nozzle rows NL in the nozzle plate 211 is not limited to four.

[0048] As described above, the nozzle row NL is arranged parallel to the width direction, and therefore, hereinafter the width direction will also be referred to as the nozzle row direction.

[0049] <First connector> 3A, the first connector 212 is a connection part with a control board (not shown) of the inkjet recording apparatus 10. The first connector 212 controls the ink ejection operation of the droplet ejection device 200.

[0050] Ink flow paths leading to the individual nozzles N of the nozzle plate 211 are formed in a head chip (not shown). Piezoelectric elements for ejecting ink from the nozzles N are individually provided in these ink flow paths. Wiring for applying a drive voltage to each piezoelectric element is connected to a first connector 212 provided on the top of the inkjet head 210. When the inkjet recording apparatus 10 is operated, the first connector 212 is connected by cable to a drive circuit on the control board and receives a drive signal from the drive circuit. This causes the piezoelectric elements to deform, causing ink to be ejected from the nozzles N.

[0051] <Second connector> The second connector 213 is a connection part to an ink tank (not shown) which is a liquid tank provided in the inkjet recording apparatus 10, and a waste liquid tank (not shown).

[0052] The second connector 213 has an inlet 213a and an outlet 213b. The inlet 213a and the outlet 213b are both connected to a manifold (not shown) inside the droplet ejection device 200. The inlet 213a supplies ink to the droplet ejection device 200 via a supply pipe connected to an ink tank. The outlet 213b discharges ink from the droplet ejection device 200 via a discharge pipe connected to a waste liquid tank.

[0053] The ink tank stores the ink ejected from the nozzles N. The waste liquid tank stores the ink that was not ejected from the nozzles N. The ink in the waste liquid tank is passed through a filter, for example, to remove foreign matter such as air bubbles and impurities, before being supplied to the ink tank.

[0054] As described above, the ink supplied from the ink tank via the inlet 213a that is not discharged from the nozzles N is returned to the waste liquid tank via the outlet 213b. The ink in the waste liquid tank is then returned to the ink tank after foreign matter has been removed. As described above, in the present invention, the inkjet head 210 is provided with an ink circulation mechanism. This circulation mechanism can suppress viscosity changes and component separation of ink that is stored in the ink tank without being ejected.

[0055] The inkjet head 210 also includes a heating unit (not shown) that heats the ink. The ink ejected from the nozzles N changes phase to a gel or sol state depending on the temperature and hardens when irradiated with energy rays such as ultraviolet rays. The heat source of the heating unit is PZT (lead zirconate titanate) or a heater. The heating unit heats the ink to a temperature at which the ink becomes sol-like under the control of the inkjet recording apparatus 10. The inkjet head 210 then ejects the heated sol-like ink. When this sol-like ink is ejected onto the recording medium S and allowed to cool naturally after impact, it quickly solidifies into a gel state.

[0056] <Cover material> The cover member 220 is attached to the mounting member 230 and / or the inkjet head 210 so as to cover the periphery excluding the connection portion of the inkjet head 210 and a nozzle plate 211 (described later). The cover member 220 prevents misalignment caused by contact with the head module by the user of the inkjet recording apparatus 10 and the resulting deterioration in print quality.

[0057] It is preferable to use a resin with a relatively low thermal expansion coefficient as the raw material for the cover member 220. With this configuration, it is possible to prevent the cover member 220 from bending when the inkjet head 210 generates heat.

[0058] Specifically, it is preferable to use PI (polyimide), PPS (polyphenylene sulfide), LCP (liquid crystal polymer), PEEK (polyether ether ketone), or the like as the raw material for the cover member 220. It is more preferable to appropriately add glass filler, carbon filler, inorganic filler, particles, fiber, or the like to these resins, but the materials are not limited to these.

[0059] <Mounting parts> The mounting member 230 is, for example, a flat plate having a generally rectangular shape when viewed from above. The mounting member 230 integrates (modularizes) multiple inkjet heads 210. The mounting member 230 includes an insertion portion 231 (see FIG. 3B) and ribs 232. The mounting member 230 is preferably made of metal, particularly an aluminum alloy, but is not limited to this. In the head unit 100, the lower surface of the mounting member 230 serves as a mounting surface 230a that abuts against the upper surface of the mounting plate 110.

[0060] <Insertion part> The insertion portion 231 is a substantially rectangular through-hole provided in the approximate center of the mounting member 230. In top view, the width direction length of the insertion portion 231 is the same as or slightly larger than the width direction length of the inkjet head 210. As shown in FIG. 3B, the longitudinal direction of the insertion portion 231 is parallel to the width direction. Two inkjet heads 210 are inserted into the insertion portion 231 from above. When the inkjet heads 210 are inserted into the insertion portion 231, the inkjet heads 210 are attached to the mounting member 230. At this time, the nozzle rows NL provided in the nozzle plate 211 are aligned along the width direction.

[0061] <Rib> The ribs 232 are protrusions provided so as to protrude downward from the lower surface of the mounting member 230 along the insertion portion 231. Providing the ribs 232 on the mounting member 230 improves the rigidity and strength.

[0062] <Mist intrusion prevention material> The mist intrusion prevention member 240 is a member that prevents ink mist from entering through gaps in the head module. The mist intrusion prevention member 240 is made of a contractile material such as a synthetic resin sheet such as PET (polyethylene terephthalate), rubber, or sponge. As shown in FIG. 3B, the mist intrusion prevention member 240 is a substantially rectangular flat plate whose width is approximately the same as or slightly narrower than the insertion portion 231. When the mist intrusion prevention member 240 is attached, it is possible to prevent ink mist that has entered through the gaps from accumulating and contaminating the inkjet head 210 or adhering to the recording medium S.

[0063] When assembling the head module, the mist intrusion prevention member 240 is attached in advance to the opposing surface of the inkjet head 210 and the inner surface or adjacent portion of the insertion portion 231. Then, after assembling the head module, gaps between the inkjet heads 210, 210, or between the mounting member 230 and the inkjet head 210 are filled with the mist intrusion prevention member 240. As a result, it is possible to prevent ink mist from entering the droplet ejection device 200.

[0064] As described above, the mist intrusion prevention member 240 is made of a contractile material, so even if the inkjet head 210 is pressed against the mist intrusion prevention member 240 when the mist intrusion prevention member 240 fills the gap, the inkjet head 210 will not shift out of position.

[0065] <Positioning part> The positioning portion P is a protrusion formed of, for example, die-cast, resin, or a predetermined metal. The positioning portion P positions the droplet discharge device 200 when the droplet discharge device 200 is attached to the attachment plate 110.

[0066] In this embodiment in which the droplet ejection device 200 is a head module, the positioning portion P is provided so as to protrude from, for example, a side portion of the rib 232. The positioning portion P is also, for example, arc-shaped when viewed from above. By bringing the positioning portion P into point contact with the positioned portion 112 of the mounting plate 110, the droplet ejection device 200 can be mounted on the mounting plate 110 in a state where it is positioned with high precision.

[0067] Two positioning portions P are provided on one surface (hereinafter referred to as the first surface) 200a of the side surface of the droplet discharge device 200 that is parallel to the nozzle row NL. In addition, two positioning portions P are provided on another surface (hereinafter referred to as the second surface) 200b different from the first surface 200a. In the following, the positioning portion P provided on the first surface 200a will be referred to as the first positioning portion Pa, and the positioning portion P provided on the second surface 200b will be referred to as the second positioning portion Pb. By providing the positioning portions P on the first surface 200a and the second surface 200b, the droplet discharge device 200 can be positioned in the transport direction and the width direction. Therefore, the droplet discharge device 200 can be stably positioned.

[0068] <First positioning part> The first positioning portion Pa is provided to position the droplet ejection device 200 in the width direction. As shown in Fig. 3B, the first positioning portion Pa is provided outside the width direction end portion of the nozzle row NL. This arrangement prevents a decrease in ejection uniformity due to the transfer of heat from the nozzle N to the positioned portion 112 via the point contact portion on the first surface 200a.

[0069] <Second positioning part> The second positioning portion Pb is provided to position the droplet ejection device 200 in the transport direction. For the same reason as the first positioning portion Pa, the second positioning portion Pb is preferably provided outside the nozzle row NL at the end in the transport direction, but is not limited to this.

[0070] The positioning part P is not limited to being provided integrally with the droplet ejection device 200. That is, for example, the positioning part P may be provided separately from the droplet ejection device 200, and attached to a predetermined location on the side of the droplet ejection device 200. Furthermore, it is sufficient that at least one positioning part P is provided in the droplet ejection device 200.

[0071] 4A shows a bottom view of one droplet ejection device 200 attached to one opening 111 of the head unit 100. As shown in FIG. 4A, the positioning portion P of the droplet ejection device 200 is in point contact with the positioned portion 112 of the mounting plate 110.

[0072] The positioning portion P and the positioned portion 112 may contain manufacturing errors. Therefore, if the positioning portion P is in surface contact with the positioned portion 112, positional deviation occurs depending on the contact point. On the other hand, if the droplet ejection device 200 and the mounting plate 110 are in point contact as in this embodiment, there is only one point of contact. Therefore, variation in the mounting position is minimized, and mounting accuracy is improved. Note that the positioning portion P may be configured to be in surface contact with the positioned portion 112 in a side view.

[0073] [Force application section] The force applying portion E is a member that biases the positioning portion P of the droplet ejection device 200 attached to the mounting plate 110 against the positioned portion 112. Therefore, as shown in Fig. 3B, the force applying portion E is provided on a surface that faces either the first surface 200a or the second surface 200b on which the positioning portion P is provided. In this embodiment, the force applying portion E is a leaf spring.

[0074] The force applying portion E is made of the same material as the positioning portion P. Therefore, the force applying portion E is made of, for example, die-cast, resin, or metal. Making the force applying portion E from the same material as the positioning portion P reduces the cost required to form the force applying portion E. The force applying portion E comes into contact with the force receiving portion 113 of the mounting plate 110 and elastically deforms, thereby biasing the droplet ejection device 200 at least in the transport direction or width direction.

[0075] In this embodiment in which the droplet ejection device 200 is a head module, the force application portion E is provided, for example, on the rib 232. The force application portion E is also disposed in an area inside the outer periphery of the attachment surface 230a.

[0076] (Positional relationship between the positioning part and the force applying part) 4A, it is preferable to provide at least one force applying unit E at a position closer to the fixed unit 120 than the positioning unit P, which is located at the farthest position in the transport direction and width direction. With this configuration, the droplet ejection device 200 can be stably biased. This configuration is particularly effective when the biasing force applied by the force applying unit E is large.

[0077] 4B, it is also preferable to provide at least one force application unit E at a position farther away than the positioning unit P, which is located farthest from the fixed unit 120 in the transport direction and width direction. With this configuration, even a force application unit E that applies a small biasing force can counteract the torque generated by the fixed unit 120. In addition, in FIGS. 4A and 4B, the positioning unit P located farthest from the fixed unit 120 in the transport direction and width direction is the first positioning unit Pa on the right side of the figure.

[0078] [Effects of this embodiment] As described above, the head unit 100 according to this embodiment includes a mounting plate 110 having an opening 111, which is a through-hole to which the droplet ejection device 200 is attached. The droplet ejection device 200 also includes a positioning portion P that contacts a positioned portion 112 of the mounting plate 110, and a force applying portion E that contacts a force applied portion 113 of the mounting plate 110 and thereby urges the positioning portion P toward the positioned portion 112. With this configuration, the force applying portion E urges the positioning portion P, thereby suppressing positional deviation after positioning and enabling high-precision image formation. Furthermore, because the droplet ejection device 200 includes the force applying portion E, there is no need to provide space for the force applying portion E on the mounting plate 110 side, allowing the head unit 100 and the inkjet recording device 10 to be miniaturized.

[0079] [Modifications, etc.] The embodiment and its modifications of the present invention have been described above, but the contents of the description of the above embodiment and modifications are preferred examples of the present invention and the present invention is not limited to these.

[0080] [Variation 1] For example, in the above example, the force applying unit E biases the droplet ejection device 200 in the width direction and the transport direction, while the fixing unit 120 fixes the droplet ejection device 200 in the height direction. However, the present invention is not limited to this. That is, as shown in FIG. 5 , the force applying unit E may be configured to contact not only the inner circumferential surface of the opening 111 but also the upper or lower surface of the mounting plate 110, thereby biasing the droplet ejection device 200 in the height direction as well. With this configuration, the fixing unit 120 becomes unnecessary. In particular, if the fixing unit 120 is a rigid part having a screw shape, there is no need to provide a screw hole in the mounting plate 110. This allows the inkjet recording device 10 to be made even more compact.

[0081] [Variation 2] Furthermore, although the droplet ejection device 200 is a head module in the above example, the present invention is not limited to this. That is, as shown in Fig. 6, the droplet ejection device 200 may be a single inkjet head 210. In this configuration, the positioning unit P and the force applying unit E are provided near the lower end of the side surface of the inkjet head 210, for example.

[0082] [Variation 3] In addition, in the above example, the positioning portion P is a protrusion and the positioned portion 112 is a flat surface, but this is not limiting. The positioning portion P may be a flat surface as shown in Fig. 7. In this configuration, the positioned portion 112 is a protrusion.

[0083] [Variation 4] Furthermore, although the configuration in which the positioned portion 112 and the force application portion 113 are the inner peripheral surface of the opening 111 has been exemplified, this is not limiting. For example, as shown in FIG. 8 , the positioned portion 112 and the force application portion 113 may be provided on the upper surface of the mounting plate 110. In this configuration, the user can visually confirm the contact between the positioning portion P and the force application portion E by looking from above. The positioned portion 112 and the force application portion 113 may also be provided on the lower surface of the mounting plate 110. In this configuration, the mounting surface 230a becomes the upper surface, not the lower surface, of the mounting member 230, and abuts against the lower surface, not the upper surface, of the mounting plate 110.

[0084] [Variation 5] Furthermore, in the above example, a configuration in which the force applying unit E generates stress parallel to the biasing direction of the droplet ejection device 200 has been exemplified, but this is not limiting. As shown in FIG. 9, the force applying unit E may generate stress at a predetermined inclination with respect to the biasing direction of the droplet ejection device 200. With this configuration, a single force applying unit E can bias the droplet ejection device 200 in both the width direction and the transport direction. In particular, as shown in FIG. 10, if the droplet ejection device 200 is provided so that the biasing direction is perpendicular to the line connecting the fixed unit 120 and the force applying unit E, the droplet ejection device 200 can be biased with a stronger biasing force.

[0085] [Variation 6] In the above example, the force application portion E is provided on the rib 232, but the present invention is not limited to this. For example, the force application portion E may be provided on the cover member 220, as shown in FIG.

[0086] [Variation 7] Furthermore, in the above example, a configuration in which the force applying unit E presses the positioning unit P of the droplet ejection device 200 against the positioned unit 112 has been described, but the present invention is not limited to this. The force applying unit E may be a tension spring. In this configuration, the force applying unit E presses the positioned unit 112 of the mounting plate 110 against the positioning unit P of the droplet ejection device 200. This configuration is particularly preferable when the droplet ejection device 200 is disposed so that the nozzle plate 211 is parallel in the height direction, as shown in FIG. 12 , for example. With this configuration, even if a leaf spring cannot be used as the force applying unit E due to a lack of space on the mounting plate 110 side, the force applying unit E, which is a tension spring, can apply a force that takes into account the weight of the droplet ejection device 200.

[0087] [Variation 8] Furthermore, as shown in FIG. 13, for example, a configuration may be provided in which a plurality of force applying units E urge the droplet discharge device 200 in the same direction.

[0088] Furthermore, in a configuration including a plurality of positioning portions P and force applying portions E, the positioning portions P and force applying portions E may each have a different shape.

[0089] [Other variations] Furthermore, in the above example, the force applying portion E is made of the same material as the positioning portion P, but this is not limiting. In other words, when the force applying portion E is to be elastically deformed, it may be made of a material different from that of the positioning portion P, such as phosphor bronze or SUS, to enhance its elasticity. Furthermore, the force applying portion E is not limited to a leaf spring. The force applying portion E may also be a sheet-like elastic body.

[0090] Furthermore, in the above example, the force applying portion E is configured to urge the droplet discharge device 200 by elastically deforming, but the present invention is not limited to this. That is, the force applying portion E may be configured to urge the droplet discharge device 200 by being bent and permanently plastically deformed when the droplet discharge device 200 is attached to the opening 111. Furthermore, the force applying portion E may be excavated as one form of plastic deformation.

[0091] Furthermore, the droplet ejection system 10 is not limited to an inkjet recording device that ejects ink. That is, the droplet ejection system 10 may be configured to eject droplets of a liquid other than ink from the nozzles N. [Explanation of symbols]

[0092] 10 Inkjet recording device (droplet ejection system) 11 Conveyor 100 Head unit (droplet ejection unit) 110 Mounting plate 113 Force applying part 120 Fixed part 200 Droplet discharge device 200a 1st page 200b 2nd page E Force applying part P Positioning part N nozzle NL nozzle row S Recording media

Claims

1. a droplet ejection device that ejects droplets from each nozzle of a nozzle array arranged on a nozzle surface; a mounting plate having an opening that is a through hole to which the droplet ejection device is attached, The droplet ejection device includes a positioning portion that contacts a positioned portion of the mounting plate; a force applying section that applies a force from the positioning section to the positioned section.

2. The droplet ejection unit according to claim 1 , wherein the force applying portion is in contact with the positioned portion so as to apply a force in a nozzle row direction and / or a transport direction perpendicular to the nozzle row direction.

3. a fixing unit that fixes the droplet ejection device to the mounting plate by applying a force from a height direction perpendicular to the nozzle surface; The droplet discharge unit according to claim 1 , wherein the droplet discharge device includes the force applying portion at a position farther from the fixing portion than the positioning portion, which is farthest in the nozzle row direction and in a transport direction perpendicular to the nozzle row direction.

4. a fixing unit that fixes the droplet ejection device to the mounting plate by applying a force from a height direction perpendicular to the nozzle surface; The droplet discharge unit according to claim 1 , wherein the droplet discharge device includes the force applying portion at a position closer to the fixing portion than the positioning portion, which is farthest in the nozzle row direction and in a transport direction perpendicular to the nozzle row direction.

5. the droplet ejection device includes at least one positioning portion on at least two surfaces, namely, a first surface parallel to the nozzle row and a second surface different from the first surface; When viewed from a height direction perpendicular to the nozzle surface, the positioning portion and the positioned portion are in point contact with each other, The droplet ejection unit according to claim 1 , wherein, on the first surface, the positioning portion and the positioned portion come into point contact outside the longitudinal end of the nozzle row.

6. The droplet discharge unit according to claim 1 , wherein the positioning portion and the force applying portion are provided between the mounting plate, a mounting surface of the droplet discharge device, and the nozzle surface.

7. The droplet discharge unit according to claim 1 , wherein a force applied portion of the mounting plate that comes into contact with the force applying portion and the positioned portion are provided on an upper surface of the mounting plate.

8. The droplet discharge unit according to claim 1 , wherein at least a part of the force applying portion is made of a rigid material different from that of the positioning portion.

9. The droplet discharge unit according to claim 1 , wherein the force applying portion is made of the same rigid material as the positioning portion.

10. The droplet discharge unit according to claim 1 , wherein the droplet discharge device includes the force applying portion positioned inside the outer periphery of a mounting surface that is a contact surface with the mounting plate.

11. The droplet discharge unit according to claim 1 , wherein the force applying portion is elastically deformable or plastically deformable.

12. A droplet ejection device that is attached to a mounting plate of a droplet ejection unit and ejects droplets from each nozzle of a nozzle array arranged on a nozzle surface, a positioning portion that contacts the mounting plate; a force applying section that applies a force to the positioning section toward the mounting plate when the droplet ejection device is attached to the mounting plate.

13. A droplet ejection unit according to any one of claims 1 to 11; A droplet ejection system including: a transport unit that transports a recording medium.

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