Droplet discharge unit, droplet discharge apparatus and droplet discharge system

Abstract

A droplet discharge unit (100) is provided with: a droplet discharge device (200) that discharges droplets from a nozzle (N) and records an image on a recording medium (S); and a mounting plate (110) provided with an opening (111) on which the droplet discharge device (200) is mounted, the droplet discharge unit (100) being provided with a point contact part (C) in which the droplet discharge device (200) and the contact surface (112) are in point contact when viewed from a direction perpendicular to the nozzle surface. At least one point contact portion (C) is provided on at least two surfaces of a first surface (300a (422a)) parallel to the nozzle row (NL) and a second surface (300b (422b)) that is a surface different from the first surface (300a (422a)) of the droplet discharge device (200), the first point contact portion (C1) of the first surface (300a (422a)) is positioned further outward than the longitudinal end of the nozzle row (NL), and the droplet discharge device (200) is provided with at least one positioning portion (P).

Description

Technical Field

[0001] The present invention relates to a liquid droplet discharge unit, a liquid droplet discharge device and a liquid droplet discharge system. Background Art

[0002] Conventionally, there is known a liquid droplet discharge system that discharges liquid from a liquid droplet discharge head (liquid droplet discharge device) toward a recording surface of a recording medium at an appropriate timing based on image data to record an image on the recording surface.

[0003] In the above droplet discharge system, there is known an invention in which a protrusion is provided on the side surface of the droplet discharge head (see, for example, Patent Documents 1 and 2). The protrusion allows the droplet discharge head to be mounted on the mounting portion of the droplet discharge system with high precision.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-061719

[0007] Patent Document 2: Japanese Patent Application Publication No. 2011-218750 Summary of the invention

[0008] However, when the droplet ejection head having the protrusion on the side is mounted on the mounting portion, the heat near the protrusion moves to the main body of the droplet ejection system via the protrusion. In addition, in the inventions of Patent Documents 1 and 2, the protrusion is formed in the arrangement direction of the nozzles in the droplet ejection head.

[0009] Therefore, in the inventions of Patent Documents 1 and 2, the temperature of the nozzle near the protrusion is lower than that of the other nozzles. Furthermore, the temperature of the droplets discharged from the nozzle near the protrusion is lower than that of the droplets discharged from the other nozzles.

[0010] As a result, there is a problem that the ejection characteristics of each nozzle in one droplet ejection head vary.

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid droplet discharge unit, a liquid droplet discharge device, and a liquid droplet discharge system that can be mounted with high accuracy and have stable discharge characteristics.

[0012] In order to solve the above problems, the invention described in claim 1 provides a liquid droplet discharge unit comprising:

[0013] a liquid droplet ejecting device that ejects liquid droplets from each nozzle of a nozzle array arranged in parallel with the longitudinal direction of the nozzle face to record an image on a recording medium; and

[0014] The mounting plate has an opening portion as a through hole for mounting the liquid droplet discharge device.

[0015] The liquid droplet discharge unit includes a point contact portion where the liquid droplet discharge device and the inner peripheral portion of the opening are in point contact when viewed from a direction perpendicular to the nozzle surface.

[0016] The point contact portion is provided at least one on at least two surfaces of the liquid droplet ejection device, namely, a first surface parallel to the nozzle array and a second surface different from the first surface.

[0017] The first point contact portion of the first surface is located outside the end portion of the nozzle array in the longitudinal direction.

[0018] The liquid droplet discharge device includes at least one positioning portion as a protrusion forming the point contact portion.

[0019] The invention described in claim 2 is the liquid droplet discharge unit described in claim 1,

[0020] The liquid droplet ejection device is a plurality of liquid droplet ejection heads.

[0021] The liquid droplet discharge unit includes a mounting member having an insertion portion into which the plurality of liquid droplet discharge heads are inserted for mounting.

[0022] The mounting member includes a rib protruding downward in the direction of droplet discharge along the insertion portion,

[0023] The rib includes the positioning portion on an outer peripheral surface portion.

[0024] The invention described in claim 3 is the liquid droplet discharge unit described in claim 1 or 2.

[0025] The positioning portion is provided on a straight portion of the liquid droplet discharge device.

[0026] The invention described in claim 4 is the liquid droplet discharge unit described in claim 1 or 2.

[0027] At least one of the point contact portions is formed by a contact surface in the inner peripheral portion of the opening portion that is parallel to or perpendicular to the nozzle array.

[0028] The invention described in claim 5 is the liquid droplet discharge unit described in claim 1 or 2.

[0029] The positioning portion is in an arc shape or a triangular shape when viewed from a direction perpendicular to the nozzle surface.

[0030] The invention described in claim 6 is the liquid droplet discharge unit described in claim 1 or 2.

[0031] The liquid droplet discharge device includes a plurality of first positioning portions on the first surface,

[0032] The aerial wire connecting the plurality of first point contact portions is parallel to the nozzle array.

[0033] The invention described in claim 7 is the liquid droplet discharge unit described in claim 1 or 2.

[0034] The liquid droplet discharge device includes a first positioning portion on the first surface and a second positioning portion on the second surface.

[0035] The second positioning portion is provided on a side closer to the first positioning portion than the center of the second surface in the arrangement direction of the nozzle array.

[0036] The invention described in claim 8 is the liquid droplet discharge unit described in claim 1 or 2.

[0037] The nozzle surface is located below a lower surface of the mounting plate when viewed from a direction perpendicular to the nozzle surface.

[0038] The invention described in claim 9 is the liquid droplet discharge unit described in claim 2.

[0039] The positioning portion is provided so as not to protrude from the outer periphery of the mounting member.

[0040] The invention described in claim 10 is the liquid droplet discharge unit described in claim 1 or 2.

[0041] A fixing member is provided for pressing and fixing the liquid droplet discharge device downward in the liquid droplet discharge direction,

[0042] The fixing member includes an elastic portion that applies a pressing force downward in the droplet discharge direction by elastic force.

[0043] The invention described in claim 11 provides a liquid droplet ejection device, which is mounted on a mounting plate of a liquid droplet ejection unit, and ejects liquid droplets from each nozzle of a nozzle array arranged parallel to the longitudinal direction of a nozzle surface to record an image on a recording medium, wherein:

[0044] The droplet ejection device includes a positioning portion that is positioned by point contact with a contact surface of the mounting plate when viewed from a direction perpendicular to the nozzle surface.

[0045] At least one of the positioning portions is provided on at least two surfaces, namely, a first surface parallel to the nozzle array and a second surface different from the first surface.

[0046] The first positioning portion provided on the first surface is provided at a position outside the longitudinal direction end portion of the nozzle array.

[0047] The invention described in claim 12 provides a liquid droplet discharge system comprising:

[0048] The liquid droplet discharge unit according to claim 1 or 2; and

[0049] The transport unit transports the recording medium.

[0050] The invention described in claim 13 is the liquid droplet discharge system described in claim 12,

[0051] A circulation mechanism is provided to circulate the liquid.

[0052] The invention described in claim 14 is the liquid droplet discharge system described in claim 13,

[0053] A heating portion is provided for heating the liquid.

[0054] According to the present invention, high-precision mounting is possible during mounting, and discharge characteristics are stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a three-dimensional diagram of the droplet discharge system.

[0056] Figure 2 It is a perspective view of a liquid droplet discharge unit to which the liquid droplet discharge device according to the first embodiment is mounted.

[0057] Figure 3A It is a schematic diagram showing an example of a fixing member.

[0058] Figure 3B It is a schematic diagram showing an example of a fixing member.

[0059] Figure 3C It is a schematic diagram showing an example of a fixing member.

[0060] Figure 4 It is a perspective view showing the liquid droplet discharge device according to the first embodiment.

[0061] Figure 5 This is a diagram showing the bottom surface of the liquid droplet discharge device according to the first embodiment.

[0062] Figure 6 is a schematic diagram showing a point contact portion.

[0063] Figure 7 It is a perspective view showing a liquid droplet discharge device according to a second embodiment.

[0064] Figure 8 This is a bottom view showing the liquid droplet discharge device according to the second embodiment.

[0065] Fig. 9A Schematic diagram showing a point contact portion according to another example.

[0066] Fig. 9B Schematic diagram showing a point contact portion according to another example.

[0067] Fig. 9C Schematic diagram showing a point contact portion according to another example.

[0068] Fig.9D Schematic diagram showing a point contact portion according to another example.

[0069] Fig.9E Schematic diagram showing a point contact portion according to another example.

[0070] Fig.9F Schematic diagram showing a point contact portion according to another example.

[0071] Figure 9G Schematic diagram showing a point contact portion according to another example.

[0072] Fig.10 It is a bottom view showing a positioning portion of another shape. DETAILED DESCRIPTION

[0073] [First embodiment]

[0074] The droplet discharge system according to the first embodiment of the present invention will be described in detail below with reference to the drawings. In the embodiments described below, various technically preferred limitations are added for implementing the present invention, but the scope of the present invention is not limited to the following embodiments and illustrations.

[0075] (Inkjet Recording Device)

[0076] First, as a liquid droplet discharge system according to the present embodiment, a configuration example of an inkjet recording apparatus 10 including an inkjet unit 100 as a liquid droplet discharge unit is disclosed.

[0077] In the following description, as shown in the drawings, the conveying direction of the recording medium S in the inkjet recording device 10 is defined as the front-to-back direction. In addition, the direction perpendicular to the conveying direction on the conveying surface of the recording medium S is defined as the left-right direction. In addition, the direction perpendicular to the front-to-back direction and the left-to-right direction (the direction in which ink is ejected) is defined as the up-down direction. In addition, regarding the inkjet unit 100 and the droplet ejection device 200 described later (see Figure 2 ), and the description will also be made based on the direction of the state in which it is installed in the inkjet recording device 10.

[0078] Figure 11 is a schematic perspective view showing an inkjet recording apparatus 10 according to the present embodiment. The inkjet recording apparatus 10 includes a conveying unit 11 and an inkjet unit 100 .

[0079] {Transportation Department}

[0080] The conveying section 11 includes two conveying rollers 11 a and a conveying belt 11 b .

[0081] The transport unit 11 transports the recording medium S in the front-rear direction.

[0082] The conveying roller 11a is Figure 1 The conveying roller 11a rotates around a rotation axis extending in the left-right direction of the conveying belt 11b. In addition, the conveying roller 11a supports the inner side of the wheel-shaped conveying belt 11b.

[0083] Moreover, on the conveying surface of the conveying belt 11 b , the recording medium S is placed so that the recording surface thereof faces upward.

[0084] When the transport roller 11 a rotates by the operation of a transport motor (not shown), the transport belt 11 b moves in a circular motion in the front-rear direction, and transports the recording medium S in the front-rear direction.

[0085] In addition, the conveying unit 11 is not limited to such a belt conveying type structure.

[0086] For example, the transport unit 11 may be a drum transport type structure including a transport drum that rotates in the transport direction while keeping the recording medium S in close contact with its outer peripheral surface.

[0087] {Recording medium}

[0088] The recording medium S is, for example, a single sheet of printing paper cut into a certain size. The recording medium S is fed onto the conveyor belt 11b from a paper feeding device (not shown). After an image or text is recorded by the inkjet unit 100, the recording medium S is discharged to a predetermined paper discharge portion.

[0089] In addition, long-sized recording media such as roll paper and continuous printing paper may be used as the recording medium S. In addition, paper such as ordinary paper and coated paper, cloth, or sheet-like resin may be used as the recording medium S. In this way, various media that fix ink dripped on the surface are used as the recording medium S.

[0090] like Figure 1 As shown in FIG. 1 , in the inkjet recording apparatus 10 , a plurality of inkjet units 100 are arranged in a row from the upstream side to the downstream side in the conveyance direction of the recording medium S. As shown in FIG.

[0091] Each inkjet unit 100 is formed from each droplet ejection device 200 (see Figure 2) The image and text are recorded by ejecting ink onto the recording medium S transported by the transport unit 11. Ink is ejected from the droplet ejecting device 200 at an appropriate timing using the inkjet unit 100 according to the image data.

[0092] also, Figure 1 Although the example in which four inkjet units 100 corresponding to four colors of ink, namely, yellow (Y), magenta (M), cyan (C), and black (K), are arranged is described, the present invention is not limited thereto.

[0093] That is, the number of inkjet units 100 included in the inkjet recording device 10 may be 3 or less or 5 or more. In addition, a plurality of inkjet units 100 that eject ink of the same color may be arranged.

[0094] {Inkjet unit}

[0095] Figure 2 One ink jet unit 100 according to this embodiment is shown.

[0096] The inkjet unit 100 includes a mounting plate 110 , a fixing member 120 , and a droplet ejection device 200 .

[0097] 〔Mounting plate〕

[0098] like Figure 2 As shown, the mounting plate 110 is a thin plate having a substantially rectangular shape extending in the left-right direction, and the liquid droplet discharge device 200 is mounted thereon.

[0099] The mounting plate 110 has a plurality of openings 111 formed therein as through holes having a substantially rectangular shape.

[0100] <Opening>

[0101] The opening 111 is a through hole that is the same as or slightly larger than the outer shape of the droplet discharge device 200 except for the extension 210 in a plan view. In addition, a plurality of openings 111 are provided in the mounting plate 110 in a staggered manner.

[0102] When the droplet discharge device 200 is mounted on the mounting plate 110, the droplet discharge device 200 is first inserted into each opening 111. Then, the droplet discharge device 200 is pressed so that the positioning portion P is in point contact with the inner peripheral portion (contact surface 112) of the opening 111 when viewed from a direction perpendicular to the nozzle surface.

[0103] Thus, the droplet discharge device 200 can be mounted on the mounting plate 110 in a state of being positioned with high accuracy.

[0104] In addition, hereinafter, the portion where the droplet discharge device 200 and the contact surface 112 are in point contact is referred to as a point contact portion C (see Figure 6 ).

[0105] In addition, Figure 2 In the embodiment, the mounting plate 110 is shown as an example on which four droplet discharge devices 200 can be mounted, but the present invention is not limited thereto. The mounting plate 110 may be configured to be capable of mounting three or less or five or more droplet discharge devices 200.

[0106] However, it is preferable that the plurality of droplet ejection devices 200 cover the entire left-right region of the recording medium S. This is because, with this configuration, an image can be formed on the entire surface of the recording medium S without moving the inkjet unit 100 left-right.

[0107] [Fixed parts]

[0108] The fixing member 120 is a member that fixes the droplet discharge device 200 mounted on the mounting plate 110 to the mounting plate 110 .

[0109] The fixing member 120 fixes the droplet discharge device 200 to the mounting plate 110 by applying downward pressing force to the extending portion 210 whose lower surface abuts against the upper surface of the mounting plate 110 .

[0110] The fixing member 120 may be configured to fix the droplet discharge device 200 to the mounting plate 110 by applying downward pressure to the extension 210 , and the structure is not limited.

[0111] In this embodiment, the fixing member 120 is, for example, Figure 3A The fixing member 120 may be a screw-shaped rigid body and an elastic body such as a spring. Figure 3B The elastic part shown in FIG. 1 is made of an elastic body such as a leaf spring. Figure 3C The elastic part shown is composed of a clamp-shaped rigid body part and an elastic body such as a spring.

[0112] However, it is not preferable that the fixing member 120 is formed only of a screw-shaped rigid body because when the liquid droplet discharge device 200 is fixed by the rotation of the screw, the position of the liquid droplet discharge device 200 may be shifted due to the rotation torque generated by the rotation.

[0113] Therefore, it is preferable that the fixing member 120 has an elastic portion formed of an elastic body and has a structure in which the droplet discharge device 200 is fixed to the mounting plate 110 by the elastic force of the elastic portion.

[0114] 〔Liquid droplet discharge device〕

[0115] The liquid droplet discharge device 200 is a device that records images and characters on a recording medium S by discharging ink droplets.

[0116] Figure 4 2 is a perspective view showing a liquid droplet discharge device 200 according to the first embodiment. Figure 5 This is a diagram showing the bottom surface of a liquid droplet discharge device 200 according to the first embodiment.

[0117] The liquid droplet discharge device 200 in the inkjet recording apparatus 10 according to the first embodiment is an inkjet head 300 .

[0118] 〔Inkjet head〕

[0119] Inkjet head 300 Figure 4 as well as Figure 5 As shown, the inkjet head 300 includes a nozzle plate 310 , a first connector 320 , a second connector 330 , and a positioning portion P. In addition, the inkjet head 300 includes a head chip (not shown) on which a driving mechanism for ejecting ink is formed.

[0120] <Nozzle Plate>

[0121] The nozzle plate 310 is a flat plate that is long in the left-right direction and arranged horizontally. Figure 5 As shown, a plurality of nozzles N are formed on a nozzle surface which is a lower surface side of the nozzle plate 310 .

[0122] The nozzles N form, for example, four nozzle rows NL parallel to the left-right direction at a uniform nozzle pitch (hereinafter referred to as x).

[0123] The four nozzle rows NL are arranged at a certain interval in the front-to-back direction. In addition, the second nozzle row NL in the front-to-back direction of the four nozzle rows NL is arranged by shifting x / 2 in the left direction (or right direction) relative to the first nozzle row NL. In addition, the third nozzle row NL is arranged by shifting x / 4 in the left direction (or right direction) relative to the first nozzle row NL. In addition, the fourth nozzle row NL is arranged by shifting x / 2 in the left direction (or right direction) relative to the third nozzle row NL.

[0124] That is, the four nozzle rows NL of the nozzle plate 310 are sequentially shifted to the left (or right) by x / 4, and dot formation with a dot pitch of x / 4 can be achieved.

[0125] In addition, the number of nozzle rows NL in the nozzle plate 310 is not limited to four.

[0126] <1st connector>

[0127] Back to Figure 4The first connector 320 is a connection portion with a control substrate (not shown) of the inkjet recording device 10 that controls the ink ejection operation of the inkjet head 300 .

[0128] In the head chip (not shown), ink flow paths communicating with the nozzles N of the nozzle plate 310 are formed. In addition, piezoelectric elements for ejecting ink from the nozzles N are independently provided in these ink flow paths. Moreover, wiring for applying a driving voltage to each piezoelectric element is connected to a first connector 320 provided on the upper portion of the inkjet head 300.

[0129] When the inkjet recording device 10 is driven, the first connector 320 is connected to the driving circuit of the control substrate by a cable, and receives a driving signal from the driving circuit. Then, the piezoelectric element is deformed, and ink is ejected from the nozzle N.

[0130] <2nd Connector>

[0131] The second connector 330 is a connection portion with an ink tank (not shown) and a waste liquid tank (not shown) as liquid tanks provided in the inkjet recording device 10 .

[0132] The second connector 330 includes an inlet 331 for supplying ink to the inkjet head 300 via a supply pipe connected to the ink tank. In addition, the second connector 330 includes an outlet 332 for discharging ink from the inkjet head 300 via a discharge pipe connected to the waste liquid tank. Both the inlet 331 and the outlet 332 are connected to a manifold (not shown) in the inkjet head 300.

[0133] The ink ejected from the nozzle N is stored in the ink tank.

[0134] Ink that has not been ejected from the nozzles N is collected and stored in the waste liquid tank. The ink in the waste liquid tank is supplied to the ink tank after foreign matter such as bubbles and inclusions are removed by passing the ink through a filter, for example.

[0135] As described above, the portion of the ink supplied from the ink tank via the inlet 331 that is not discharged from the nozzle N is returned to the waste liquid tank via the outlet 332. The ink in the waste liquid tank is returned to the ink tank after foreign matter is removed.

[0136] As described above, in the present invention, the inkjet head 300 includes an ink circulation mechanism. This circulation mechanism can suppress changes in viscosity and component separation of the ink that is not ejected but stored in the liquid tank.

[0137] In addition, the second connector 330 may be provided on the upper surface of the inkjet head 300 similarly to the first connector 320 .

[0138] The inkjet head 300 includes a heating unit (not shown) for heating the ink. The ink ejected from the nozzles N has a property of changing phase into a gel or sol state due to temperature and hardening when irradiated with energy rays such as ultraviolet rays.

[0139] 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 a sol under the control of the inkjet recording device 10. The inkjet head 300 ejects the heated sol-like ink. When the sol-like ink is ejected onto the recording medium S and drips onto the recording medium S and then naturally cools, it quickly becomes a gel and solidifies.

[0140] <Positioning section>

[0141] The positioning portion P is a protrusion provided in the liquid droplet discharge device 200 among the protrusions forming the point contact portion C.

[0142] The positioning portion P positions the liquid droplet discharge device 200 in the opening 111 when the liquid droplet discharge device 200 is mounted on the mounting plate 110 .

[0143] In the present embodiment where the droplet discharge device 200 is an inkjet head 300, the positioning portion P is provided at, for example, the lower end of the side surface of the inkjet head 300. The positioning portion P is, for example, arc-shaped in a plan view and protrudes from the side surface of the inkjet head 300.

[0144] By making the positioning portion P come into point contact with the contact surface 112 of the mounting plate 110 , the droplet discharge device 200 is mounted on the mounting plate 110 in a state of being positioned with high accuracy.

[0145] The positioning portion P is provided on one surface (hereinafter referred to as the first surface) 300a parallel to the nozzle array NL among the side surfaces of the inkjet head 300. The positioning portion P is provided on one surface (hereinafter referred to as the second surface) 300b different from the first surface 300a.

[0146] Hereinafter, the positioning portion P provided on the first surface 300 a is referred to as a first positioning portion Pa, and the positioning portion P provided on the second surface 300 b is referred to as a second positioning portion Pb for distinction.

[0147] When the positioning portion P is provided on the first surface 300 a and the second surface 300 b , the liquid droplet discharge device 200 can be positioned in the front-rear direction and the left-right direction.

[0148] 《1st Positioning Department》

[0149] The first positioning portion Pa is provided to position the inkjet head 300 in the left-right direction.

[0150] The first positioning portion Pa is as follows Figure 5As shown in FIG. 1 , the nozzle row NL is arranged outside the end portion in the longitudinal direction (left-right direction). When this configuration is adopted, it is possible to prevent the heat of the nozzle N from being transmitted through the point contact portion C in the first surface 300a, that is, the first point contact portion C1 (see FIG. 1 ). Figure 6 ) moves to the contact surface 112, resulting in a decrease in discharge uniformity.

[0151] <<Second Positioning Section>>

[0152] The second positioning portion Pb is provided for positioning the inkjet head 300 in the front-rear direction.

[0153] The second positioning portion Pb is preferably provided on the front side of the front nozzle row NL or on the rear side of the rear nozzle row NL for the same reason as the first positioning portion Pa, but is not limited thereto.

[0154] In addition, hereinafter, the point contact portion C on the second surface 300b is referred to as the second point contact portion C2 (see Figure 6 ).

[0155] The positioning part P is not limited to the structure provided in the inkjet head 300. That is, for example, the positioning part P may be provided separately from the inkjet head 300 and attached to a predetermined position on the side surface of the inkjet head 300.

[0156] In addition, at least one positioning portion P may be provided in the droplet discharge device 200 .

[0157] Figure 6 The top cross-sectional view of one liquid droplet ejection device 200 attached to one opening 111 in the ink jet unit 100 is shown.

[0158] like Figure 6 As shown, in a plan view, the droplet discharge device 200 is in point contact with the contact surface 112 of the mounting plate 110 to form a point contact portion C. Alternatively, the droplet discharge device 200 may be in surface contact with the contact surface 112 in a side view.

[0159] The positioning portion P and the contact surface 112 include manufacturing errors. Therefore, when the positioning portion P is set to be in surface contact with the contact surface 112, a positional deviation corresponding to the contact portion occurs. On the other hand, as described in this embodiment, when the droplet discharge device 200 and the mounting plate 110 are in point contact to form the point contact portion C, the contact point becomes one. Therefore, the deviation of the mounting position is suppressed to a minimum, and the mounting accuracy is improved.

[0160] [Effects of the First Embodiment]

[0161] As described above, in the inkjet recording device 10 according to the first embodiment, the droplet ejection device 200 is an inkjet head 300. In addition, the droplet ejection device 200 includes at least one first positioning portion Pa and at least one second positioning portion Pb, and forms at least one point contact portion C on the first surface 300a and at least one point contact portion C on the second surface 300b. In addition, the first point contact portion C1 of the point contact portion C is disposed outside the end portion of the nozzle row NL in the longitudinal direction.

[0162] According to this structure, the inkjet head 300 is mounted on the mounting plate 110 in a state where it is positioned with high accuracy in the left-right direction and the front-back direction.

[0163] In addition, the heat of the nozzle N near the first point contact portion C1 can be prevented from transferring to the mounting plate 110 via the first point contact portion C1. Furthermore, the temperature difference between the nozzle N near the first point contact portion C1 and other nozzles N can be prevented from causing variations in ejection performance.

[0164] In the inkjet recording device 10 including a circulation mechanism for circulating ink, a predetermined thermal uniformity is required for the ink. Therefore, it is preferable to reduce the temperature difference of the nozzles N and suppress the temperature drop of the undischarged ink by the above-mentioned configuration.

[0165] In the inkjet recording device 10 having not only a circulation mechanism but also a heating unit for heating ink, higher thermal uniformity is required for the ink. Therefore, it is more preferable to reduce the temperature difference of the nozzle N and suppress the temperature drop of the undischarged ink by the above configuration.

[0166] In addition, the droplet discharge unit 100 includes a fixing member 120 having an elastic portion that applies a downward pressing force by an elastic force.

[0167] According to this structure, the droplet discharge device 200 can be fixed not only in the front-back direction and the left-right direction but also in the up-down direction. Therefore, positional deviation is less likely to occur in the droplet discharge device 200.

[0168] Furthermore, since the pressing force is applied by the elastic force, positional deviation is less likely to occur when the liquid droplet discharge device 200 is fixed by the fixing member 120 .

[0169] [Second embodiment]

[0170] Next, based on Figure 7 as well as Figure 8 The inkjet recording device 10 according to the second embodiment will be described in detail.

[0171] In the following description, the same reference numerals are given to the same structures as those of the inkjet recording apparatus 10 according to the first embodiment, and description thereof will be omitted.

[0172] The difference in the second embodiment is that the droplet ejection device 200 is an inkjet head module 400 formed by modularizing a plurality of inkjet heads (droplet ejection heads) 300. In addition, the difference in the second embodiment is that the positioning portion P is not provided on the inkjet head 300 but on the rib 422 of the inkjet head module 400.

[0173] When the liquid droplet discharge device 200 is provided as the inkjet head module 400 , it is possible to further improve the dot pitch when recording an image.

[0174] 〔Inkjet head module〕

[0175] like Figure 7 As shown in FIG. 4 , the inkjet head module 400 includes a plurality of inkjet heads 300, a covering member 410, a mounting member 420, and a positioning portion P. Figure 8 As shown, the inkjet head module 400 includes a mist intrusion prevention member 430 .

[0176] In addition, although the inkjet head module 400 including two inkjet heads 300 is exemplified below, the present invention is not limited thereto. That is, the inkjet head module 400 may include three or more inkjet heads 300 .

[0177] In addition, if Figure 8 As shown, the following exemplifies a case where the plurality of inkjet heads 300 are arranged in a direction perpendicular to the nozzle array NL, but the present invention is not limited thereto.

[0178] <Covering Parts>

[0179] The cover member 410 is mounted on the mounting member 420 and / or the inkjet head 300 so as to cover the periphery of the inkjet head 300 except for the connection portion and the nozzle plate 310. In addition, positional displacement caused by the user of the droplet ejection device 200 touching the inkjet head 300 and the associated reduction in print quality are suppressed.

[0180] It is preferable to use a resin with a relatively low thermal expansion coefficient as a raw material for the cover member 410. According to this structure, it is possible to suppress the cover member 410 from bending when the inkjet head 300 generates heat.

[0181] Specifically, PI (polyimide), PPS (polyphenylene sulfide), LCP (Liquid Crystal Polymer) or PEEK (polyetheretherketone) is preferably used as a raw material for the covering member 410. In addition, it is more preferable to appropriately add glass fillers, carbon fillers, inorganic fillers, particles or optical fibers to these resins, but the present invention is not limited thereto.

[0182] <Installation Parts>

[0183] The mounting member 420 is, for example, a substantially rectangular flat plate in a plan view, and integrates (modularizes) the plurality of inkjet heads 300. The mounting member 420 includes an insertion portion 421 and ribs 422.

[0184] The mounting member 420 is preferably made of metal, particularly aluminum alloy, but is not limited thereto.

[0185] <<Insert section>>

[0186] The insertion portion 421 is a through hole provided at a substantially central portion of the mounting member 420, and its width in the left-right direction is the same as or slightly larger than the width of the inkjet head 300 when viewed from above. Figure 8 As shown, the insertion portion 421 is substantially rectangular in shape, and its longitudinal direction is parallel to the left-right direction, and two inkjet heads 300 are inserted therein.

[0187] When the inkjet head 300 is inserted into the insertion portion 421, the inkjet head 300 is mounted on the mounting member 420. At this time, the nozzle array NL provided on the nozzle plate 310 is in a state along the left-right direction.

[0188] <<Ribs>>

[0189] The rib 422 is a protrusion provided so as to protrude downward from the lower surface portion of the mounting member 420 along the insertion portion 421 .

[0190] When the ribs 422 are provided on the mounting member 420, the rigidity and strength are improved.

[0191] <Anti-fog intrusion parts>

[0192] The mist intrusion prevention member 430 is a member for preventing ink mist from entering through the gap of the inkjet head module 400. When the mist intrusion prevention member 430 is installed, the ink mist entering through the gap can be prevented from accumulating and contaminating the inkjet head 300 or adhering to the recording medium S.

[0193] like Figure 8 As shown, the anti-fog intrusion component 430 is a substantially rectangular flat plate having a width in the left-right direction equal to or slightly narrower than the insertion portion 421. In addition, the anti-fog intrusion component 430 is composed of a synthetic resin sheet such as PET (polyethylene terephthalate), rubber or sponge and other contractile components.

[0194] When the inkjet head module 400 is assembled, the mist intrusion prevention member 430 is previously attached to the facing surface of the inkjet head 300, the inner surface of the insertion portion 421, or the proximal portion. Thus, after the inkjet head module 400 is assembled, the gaps between the inkjet heads 300 or between the mounting member 420 and the inkjet head 300 are filled with the mist intrusion prevention member 430. As a result, the ink mist can be prevented from intruding into the inkjet head 300.

[0195] On the other hand, the mist intrusion prevention member 430 is formed of a member having contraction properties. Therefore, when the gap is filled with the mist intrusion prevention member 430, even if the inkjet head 300 is pressed, the mounting position thereof does not shift.

[0196] In addition, in the inkjet head module 400 according to the second embodiment, the mist intrusion prevention member 430 is not an essential structure.

[0197] <Positioning section>

[0198] In the liquid droplet discharge device 200 according to the second embodiment, the positioning portion P is provided on the rib 422 .

[0199] Specifically, the positioning portion P is provided on the first surface 422a, which is a surface parallel to the nozzle row NL, among the outer peripheral surfaces of the rib 422. In addition, the positioning portion P is provided on the second surface 422b, which is a surface different from the first surface 422a, among the outer peripheral surfaces of the rib 422. More specifically, similarly to the first embodiment, the first positioning portion Pa is provided so as to form the first point contact portion C1 on the outer side of the longitudinal direction end of the nozzle row NL in the first surface 422a.

[0200] In addition, if Figure 8 As shown, the positioning portion P involved in the second embodiment is preferably set not to protrude from the outer periphery of the mounting member 420. The reason is that when the positioning portion P protrudes from the outer periphery of the mounting member 420, the contact in the stage of mounting the inkjet head module 400 on the mounting plate 110 increases, and there is a possibility that the positioning portion P is worn.

[0201] [Effects of the Second Embodiment]

[0202] As described above, the droplet discharge device 200 according to the second embodiment is an inkjet head module 400 including a plurality of inkjet heads 300. In the second embodiment, the positioning portion P is provided on the rib 422 that protrudes downward along the insertion portion 421.

[0203] With this structure, the inkjet head module 400 is also mounted on the mounting plate 110 in a state of being positioned with high accuracy by the positioning portion P.

[0204] In addition, the heat of the nozzle N near the first point contact portion C1 can be prevented from transferring to the mounting plate 110 via the first point contact portion C1. Furthermore, the temperature difference between the nozzle N near the first point contact portion C1 and other nozzles N can be prevented from causing variations in ejection performance.

[0205] Furthermore, since the mounting member 420 includes the rib 422 , it is possible to suppress damage or positional deviation in the insertion portion 421 when the liquid droplet discharge device 200 is mounted on the inkjet recording device 10 .

[0206] In addition, the positioning portion P is provided so as not to protrude from the outer periphery of the mounting member 420 .

[0207] According to this structure, it is possible to suppress damage when the liquid droplet discharge device 200 is attached to the inkjet recording device 10 .

[0208] Furthermore, of course, the inkjet head 300 according to the second embodiment may be provided with protrusions similar to the positioning portion P of the inkjet head 300 according to the first embodiment. With this configuration, the inkjet head 300 is mounted in a state of being positioned with high accuracy with respect to the mounting member 420 .

[0209] [Other preferred structures]

[0210] Hereinafter, a preferred configuration common to the droplet discharge devices 200 of the first embodiment and the second embodiment will be described.

[0211] like Figure 2 As shown, the droplet discharge device 200 is preferably configured such that the nozzle surface is located below the lower surface of the mounting plate 110 when the droplet discharge device 200 is mounted on the mounting plate 110 .

[0212] With this configuration, the nozzle surface and the recording medium S are brought closer together, so that variations in droplet discharge are reduced and drawing accuracy is improved.

[0213] In addition, if Figure 6 As shown, it is preferred that the point contact portions C be provided at three or more locations.

[0214] This is because, with this structure, the droplet discharge device 200 is less likely to be displaced even when subjected to external force, and thus the stability is improved.

[0215] In addition, preferably Figure 5 as well as Figure 8 As shown in FIG. 1 , at least one first positioning portion Pa is provided outside each of the two ends of the nozzle row NL.

[0216] The first surface 300a (422a) is parallel to the nozzle row NL and has a larger area than the second surface 300b (422b). Therefore, when the first positioning portion Pa is provided so as to increase the distance, the stability when mounted on the mounting plate 110 is improved.

[0217] In addition, preferably Figure 5 as well as Figure 8 As shown in FIG. 1 , the first positioning portion Pa is provided so that the aerial line connecting two or more first point contact portions C1 is parallel to the nozzle row NL.

[0218] This is because, with this structure, after the droplet discharge device 200 is mounted on the mounting plate 110 , positional displacement is unlikely to occur even when an external force is applied.

[0219] In addition, preferably Figure 5 as well as Figure 8 As shown, the second positioning portion Pb is provided on the first surface 300a (422a) side relative to the center of the second surface 300b (422b) in the arrangement direction (front-rear direction) of the nozzle row NL.

[0220] This is because, with this structure, even if the first surface 300a (422a) including the first positioning portion Pa is deformed by an external force, the amount of displacement of the first positioning portion Pa is reduced.

[0221] In addition, preferably Figure 6 As shown, the first point contact portion C1 is formed by the contact surface 112 parallel to the nozzle row NL. Alternatively, the point contact portion C in the second surface 300b (422b), that is, the second point contact portion C2, is preferably formed by the contact surface 112 perpendicular to the nozzle row NL.

[0222] This is because, with this configuration, even if there is a cross deviation in the positioning portion P, it is less likely to be affected by it.

[0223] In addition, it is not necessary for all point contact portions C to be formed by the contact surface 112 parallel to or perpendicular to the nozzle row NL. It is sufficient for at least one point contact portion C to be formed by the contact surface 112 parallel to or perpendicular to the nozzle row NL.

[0224] In addition, preferably Figure 5 as well as Figure 8 As shown, the positioning portion P is provided on a straight line portion which is a flat surface among the side surfaces of the liquid droplet discharge device 200 .

[0225] This is because, when the positioning portion P is provided at a corner or a concave portion of the liquid droplet discharge device 200 , the formation position thereof becomes unstable during the manufacturing process of the liquid droplet discharge device 200 .

[0226] As mentioned above, although embodiment and its modification example of this invention were described, the description content in the said embodiment and modification example is only a preferred example of this invention, and is not limited to this.

[0227] For example, you can also Fig. 9A As shown, a positioning portion P is provided at a corner of the liquid droplet discharge device 200. In this structure, the protrusion at the corner is a first positioning portion Pa provided on the first surface 300a, and is a second positioning portion Pb provided on the second surface 300b.

[0228] In addition, you can also Fig. 9B as well as Fig.9D As shown, the liquid droplet discharge unit 100 is configured such that a point contact portion C is formed by providing a protrusion on the inner peripheral portion of the opening 111 .

[0229] In addition, you can also Fig. 9C As shown in FIG. 1 , the liquid droplet discharge unit 100 is assumed to be formed with a contact surface 112 which is not parallel to or perpendicular to the nozzle row NL.

[0230] In addition, you can also Fig.9E As shown, the droplet discharge device 200 includes a droplet discharge unit 100 having a flat positioning portion P in a plan view and forming a point contact portion C with a protrusion on the inner peripheral portion of the opening 111 .

[0231] In addition, you can also Fig.9F as well as Figure 9G As shown, the liquid droplet discharge unit 100 is configured such that a protrusion provided on the inner peripheral portion of the opening 111 forms a point contact portion C with two surfaces of the liquid droplet discharge device 200 .

[0232] In addition, you can also Fig. 9B and FIG. 9D to FIG. 9G As shown in FIG. 1 , the droplet discharge device 200 does not have a structure including both the first positioning portion Pa and the second positioning portion Pb.

[0233] However, it is preferred that Figure 6 As shown in FIG. 1 , the droplet discharge device 200 includes a first positioning portion Pa and a second positioning portion Pb, and the point contact portion C is a contact portion between the protrusion and the contact surface 112 which is a flat surface. The reason for this is that when the droplet discharge device 200 is provided with a positioning protrusion and the inner peripheral portion of the opening 111 of the mounting plate 110 is made flat, it is easier to manufacture.

[0234] In addition, the positioning portion P of the present invention may be in any shape that makes point contact with the contact surface 112 and is not limited to an arc shape in a plan view.

[0235] Therefore, for example, the positioning portion P may also be as follows Fig.10 The shown triangle shape when viewed from above.

[0236] In addition, not all positioning portions P need have the same shape, and may have different shapes.

[0237] Furthermore, the present invention is not limited to the inkjet recording device 10 , and may be any other droplet ejecting device that ejects droplets of liquid other than ink from the nozzles N.

[0238] Industrial Applicability

[0239] The present invention can be used in a method for driving a droplet ejection head, a droplet ejection device, and a program in which productivity is not reduced even when a new drive pulse is added.

[0240] (Explanation of symbols)

[0241] 10: inkjet recording device (droplet ejection system); 11: conveying portion; 100: inkjet unit (droplet ejection unit); 110: mounting plate; 111: opening portion; 112: contact surface; 120: fixing component; 200: droplet ejection device; 300: inkjet head (droplet ejection head); 300a: first surface; 300b: second surface; 400: inkjet head module; 420: mounting component; 421: insertion portion; 422: rib; 422a: first surface; 422b: second surface; C: point contact portion; C1: first point contact portion; P: positioning portion; Pa: first positioning portion; Pb: second positioning portion; N: nozzle; NL: nozzle array; S: recording medium.

Claims

1. A droplet discharge unit comprising: a liquid droplet ejecting device that ejects liquid droplets from each nozzle of a nozzle array arranged in parallel with the longitudinal direction of the nozzle face to record an image on a recording medium; and The mounting plate has an opening portion as a through hole for mounting the liquid droplet discharge device. in, The liquid droplet discharge unit includes a point contact portion where the liquid droplet discharge device and the inner peripheral portion of the opening are in point contact when viewed from a direction perpendicular to the nozzle surface. The point contact portion is provided at least one on at least two surfaces of the liquid droplet ejection device, namely, a first surface parallel to the nozzle array and a second surface different from the first surface. The first point contact portion of the first surface is located outside the end portion of the nozzle array in the longitudinal direction. The liquid droplet discharge device includes at least one positioning portion as a protrusion forming the point contact portion.

2. The liquid droplet discharge unit according to claim 1, wherein: The liquid droplet ejection device is a plurality of liquid droplet ejection heads. The liquid droplet discharge unit includes a mounting member having an insertion portion into which the plurality of liquid droplet discharge heads are inserted for mounting. The mounting member includes a rib protruding downward in the direction of droplet discharge along the insertion portion, The rib includes the positioning portion on an outer peripheral surface portion.

3. The liquid droplet discharge unit according to claim 1 or 2, wherein: The positioning portion is provided on a straight portion of the liquid droplet discharge device.

4. The liquid droplet discharge unit according to claim 1 or 2, wherein: At least one of the point contact portions is formed by a contact surface in the inner peripheral portion of the opening portion that is parallel to or perpendicular to the nozzle array.

5. The liquid droplet discharge unit according to claim 1 or 2, wherein: The positioning portion is in an arc shape or a triangular shape when viewed from a direction perpendicular to the nozzle surface.

6. The liquid droplet discharge unit according to claim 1 or 2, wherein: The liquid droplet discharge device includes a plurality of first positioning portions on the first surface, The aerial wire connecting the plurality of first point contact portions is parallel to the nozzle array.

7. The liquid droplet discharge unit according to claim 1 or 2, wherein: The liquid droplet discharge device includes a first positioning portion on the first surface and a second positioning portion on the second surface. The second positioning portion is provided on a side closer to the first positioning portion than the center of the second surface in the arrangement direction of the nozzle array.

8. The liquid droplet discharge unit according to claim 1 or 2, wherein: The nozzle surface is located below a lower surface of the mounting plate when viewed from a direction perpendicular to the nozzle surface.

9. The liquid droplet discharge unit according to claim 2, wherein: The positioning portion is provided so as not to protrude from the outer periphery of the mounting member.

10. The liquid droplet discharge unit according to claim 1 or 2, wherein: A fixing member is provided for pressing and fixing the liquid droplet discharge device downward in the liquid droplet discharge direction, The fixing member includes an elastic portion that applies a pressing force downward in the droplet discharge direction by elastic force.

11. A liquid droplet ejection device, mounted on a mounting plate of a liquid droplet ejection unit, ejecting liquid droplets from each nozzle of a nozzle array arranged parallel to the longitudinal direction of a nozzle surface to record an image on a recording medium, wherein: The droplet ejection device includes a positioning portion that is positioned by point contact with a contact surface of the mounting plate when viewed from a direction perpendicular to the nozzle surface. At least one of the positioning portions is provided on at least two surfaces, namely, a first surface parallel to the nozzle array and a second surface different from the first surface. The first positioning portion provided on the first surface is provided at a position outside the longitudinal direction end portion of the nozzle array.

12. A liquid droplet dispensing system comprising: The liquid droplet discharge unit according to claim 1 or 2; and The transport unit transports the recording medium.

13. The liquid droplet discharge system according to claim 12, wherein: A circulation mechanism is provided to circulate the liquid.

14. The liquid droplet discharge system according to claim 13, wherein: A heating portion is provided for heating the liquid.

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