Liquid discharge head device and device for discharging liquid

Abstract

To suppress generation of a nozzle pitch outside a permitted range at a seam part of a nozzle array between liquid discharge heads adjacent to each other being shifted in a head short direction.SOLUTION: A liquid discharge head device 6 having a head holding member 61 for holding a plurality of liquid discharge heads 3 and 4 so as to be shifted in head short and longitudinal directions comprises: a first base attachment member 61a that fixes and attaches one head longitudinal end of the head holding member to a mount; and a second base attachment member 61b that attaches the other head longitudinal end of the head holding member to a base member so as to permit displacement in the head longitudinal direction with respect to the base member caused by expansion or contraction of the head holding member.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a liquid ejection head device and a device for ejecting a liquid.

Background Art

[0002] Conventionally, there has been known a liquid ejection head device including a plurality of liquid ejection heads each having a nozzle row in which a plurality of nozzles are arranged in the head longitudinal direction, and a head holding member that holds the plurality of liquid ejection heads such that the plurality of liquid ejection heads are displaced from each other in the head short direction and the head longitudinal direction.

[0003] For example, Patent Document 1 discloses an inkjet recording head (liquid ejection head device) having four head bodies (liquid ejection heads) each having two nozzle rows in which a plurality of nozzles are arranged in the head longitudinal direction, and a holding member (head holding member) to which the four head bodies are fixed. In this inkjet recording head, the four head bodies are arranged in a staggered manner such that they are displaced from each other in the head short direction and the head longitudinal direction. As a result, a nozzle region in which nozzles are continuous is formed in the head longitudinal direction with a length approximately four times that of the nozzle row of one head body and at a predetermined nozzle pitch (a nozzle pitch within a predetermined allowable range) by a total of four head bodies.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional liquid ejection head device, there has been a problem that a nozzle pitch outside the allowable range may occur at the joint portion of the nozzle rows between adjacent liquid ejection heads displaced in the head short direction.

Means for Solving the Problems

[0005] In order to solve the above-described problems, the present invention provides a liquid ejection head device having: a plurality of liquid ejection heads each including a nozzle array in which a plurality of nozzles are arranged in the head longitudinal direction; and a head holding member that holds the plurality of liquid ejection heads such that the plurality of liquid ejection heads are displaced from each other in the head short-side direction and the head longitudinal direction, the liquid ejection head device including: a first base attachment member that fixes and attaches one end portion of the head holding member in the head longitudinal direction to a base member; and a second base attachment member that attaches the other end portion of the head holding member in the head longitudinal direction to the base member such that displacement in the head longitudinal direction with respect to the base member is possible due to expansion or contraction of the head holding member.

Advantages of the Invention

[0006] According to the present invention, it is possible to suppress the occurrence of a nozzle pitch that is out of the allowable range at the joint portion of the nozzle arrays between the liquid ejection heads that are adjacent to each other with a shift in the head short-side direction.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment in which the liquid ejection head device according to the present invention is applied to a head unit of an inkjet recording device as an image forming device that ejects liquid will be described.

[0009] First, the head unit in the present embodiment will be described. FIG. 1 is a plan view of the head unit 2 as viewed from the normal direction of the recording material P0. The recording material P0 is, for example, paper, and may be roll paper (continuous paper) or cut paper, etc. Also, various media other than paper (such as cloth) may be used. The recording material P0 is conveyed along the conveyance direction indicated by the arrow in FIG. 1. The head unit 2 is supported so as to face the recording surface of the recording material P0 while maintaining a predetermined distance.

[0010] The head unit 2 includes a K recording unit 2K, a C recording unit 2C, an M recording unit 2M, and a Y recording unit 2Y as liquid ejection head devices for each color provided corresponding to each ink (liquid) of black (K), cyan (C), magenta (M), and yellow (Y).

[0011] The recording units 2K, 2C, 2M, 2Y for each color have three liquid ejection head devices 6A, 6B, 6C each having two recording heads 3, 4 as liquid ejection heads mounted on a mount 2a as a base member. Each of the liquid ejection head devices 6A, 6B, 6C has the same configuration, and the recording heads 3 and 4 also have the same configuration. As shown in FIG. 1, the two recording heads 3, 4 provided in each of the liquid ejection head devices 6A, 6B, 6C are arranged so as to be displaced from each other in the head short-side direction (the vertical direction in FIG. 1) and the head long-side direction (the left-right direction in FIG. 1).

[0012] In addition, in this embodiment, although a part of each nozzle row of the two recording heads 3 and 4 is arranged so as to overlap with each other in the head longitudinal direction, it is not limited to this. For example, each nozzle row of the two recording heads 3 and 4 may not overlap with each other in the head longitudinal direction, and the two recording heads 3 and 4 may be arranged such that the nozzle pitch between the end nozzles located at one end of each nozzle row of the two recording heads 3 and 4 becomes a predetermined nozzle pitch.

[0013] In each of the recording units 2K, 2C, 2M, and 2Y for each color, also for the two recording heads 3 and 4 straddling between two adjacent liquid ejection head devices 6A, 6B, and 6C, they are displaced from each other in the head short direction and are arranged such that a part of each nozzle row overlaps with each other in the head longitudinal direction (the left - right direction in FIG. 1). Thus, three liquid ejection head devices 6A, 6B, and 6C are provided. As a result, in each of the recording units 2K, 2C, 2M, and 2Y for each color, as shown in FIG. 1, the recording heads 3 and 4 are arranged in a staggered manner along the recording material width direction (the direction orthogonal to the conveyance direction), which is the head longitudinal direction.

[0014] In each of the recording units 2K, 2C, 2M, and 2Y for each color, by arranging the recording heads 3 and 4 in this way, the recording range in the head longitudinal direction of the entire recording unit (the range where an image can be recorded by the ink ejected from the nozzles 5) can be expanded. As a result, a recording unit having a recording range over the width direction of the recording material P0 can be obtained, and a line - type head unit 2 can be realized. Therefore, an image can be formed on the recording material P0 in one pass without scanning the head unit 2.

[0015] Note that the number of recording units mounted on the head unit 2, the number of recording heads arranged in the recording unit, the type of liquid (such as the color of ink) ejected from the recording unit, etc. can be arbitrarily set. Therefore, for example, the head unit 2 may be a head unit that includes only the black - only recording unit 2K and performs recording in black single color.

[0016] FIG. 2 is an explanatory diagram showing the head arrangement of the recording heads 3 and 4 provided for each recording unit of the head unit 2. The recording heads 3 and 4 have a nozzle row in which a plurality of nozzles 5 are arranged in the head longitudinal direction (for example, a nozzle row composed of 800 nozzles). In the present embodiment, an example in which the nozzle row is one row will be described, but a configuration in which two or more nozzle rows are arranged side by side in the recording material conveyance direction may also be used. Further, the nozzle row may be arranged such that the nozzle row direction is inclined with respect to the head longitudinal direction.

[0017] FIG. 3 is an explanatory diagram showing the relationship between the nozzle pitches of the two recording heads 3 and 4 on each of the liquid ejection head devices 6A, 6B, and 6C. On one of the liquid ejection head devices 6A, 6B, and 6C in the present embodiment, one of the two recording heads 3 and 4, the recording head 3, partially overlaps with the other recording head 4, and a part of each nozzle row overlaps with each other in the head longitudinal direction.

[0018] In the nozzle row provided in the recording heads 3 and 4 of the present embodiment, there are a normal region as a first nozzle group in which the nozzles 5 are arranged at a normal pitch P1, and a narrow region as a second nozzle group in which the nozzles 5 are arranged at a pitch P2 narrower than the normal pitch P1. In the present embodiment, most of the nozzle row is a normal region, but a narrow region is provided only on one end side of the nozzle row. Instead of the narrow region, a wide region in which the nozzles 5 are arranged at a pitch wider than the normal pitch P1 may be adopted.

[0019] That is, in the present embodiment, in the nozzle row overlapping portion (overlap region) between the recording head 3 and the recording head 4, it is only necessary that the nozzle pitch P2 of the recording head 3 and the nozzle pitch P1 of the recording head 4 are different. With such a configuration, even without highly accurate positioning between the recording head 3 and the recording head 4, in the overlap region, the nozzle at which the deviation in the head longitudinal direction position between the recording head 3 and the recording head 4 becomes the minimum is determined. Therefore, if each recording head is operated so that the nozzles used by the respective recording heads 3 and 4 are switched at this nozzle, it is possible to suppress recording unevenness due to pitch deviation (becoming a nozzle pitch outside the allowable range) at the switching position of the recording width between the recording heads 3 and 4.

[0020] Note that the nozzle (nozzle switching position) at which the deviation in the head longitudinal direction position between the recording head 3 and the recording head 4 becomes the minimum may be a position where, for example, after assembling the head unit 2, ink is actually ejected and the dot pitch cannot be distinguished, even if the deviation in the head longitudinal direction position between the recording head 3 and the recording head 4 deviates from the minimum. The determined nozzle switching position is stored in the storage unit 620 described later.

[0021] The above description is about the nozzle switching position in the nozzle row overlapping portion (overlap region) between the two recording heads 3 and 4 on each of the individual liquid ejection head devices 6A, 6B, and 6C. The same also applies to the nozzle switching positions of the two recording heads 3 and 4 spanning between two adjacent liquid ejection head devices 6A and 6B.

[0022] In addition, in the present embodiment, both the normal pitch P1 and the narrow pitch P2 are set to be the same pitch between the recording head 3 and the recording head 4. Therefore, as the recording heads 3 and 4, those having the same configuration can be used for each other. Accordingly, the liquid ejection head devices 6A, 6B, and 6C of the present embodiment can be manufactured by preparing only one type of recording head, and the manufacturing cost can be reduced as compared with the case where the recording heads 3 and 4 have different configurations respectively.

[0023] Note that, in the present embodiment, the nozzle rows of the recording heads 3 and 4 are an example in which a normal region and a narrow region exist, but an example in which the entire region of the nozzle row is a normal region with the normal pitch P1 may also be used.

[0024] FIG. 4 is a block diagram showing the hardware configuration of the control system of the inkjet recording apparatus 1 on which the above-described head unit 2 is mounted. In addition to the above-described head unit 2, the inkjet recording apparatus 1 is configured such that a control unit 600, a conveyance drive unit 710, an operation display unit 720, and an input / output interface 730 are interconnected via a bus line 740.

[0025] The head unit 2 is provided with a head drive unit 20 that drives the recording heads 3 and 4 disposed in the recording units 2K, 2C, 2M, and 2Y of each color. The head drive unit 20 generates a drive waveform that deforms each piezoelectric element, which is an electromechanical conversion element serving as an actuator in each of the recording heads 3 and 4 of each of the recording units 2K, 2C, 2M, and 2Y, in accordance with a control signal input from the control unit 600. When this drive waveform is input to each piezoelectric element of each of the recording heads 3 and 4 of each of the recording units 2K, 2C, 2M, and 2Y, the liquid in the pressure chamber communicating with the nozzle 5 is pressurized and ejection energy is applied, and ink is ejected from the corresponding nozzle 5.

[0026] The control unit 600 includes a CPU (Central Processing Unit) 610, a storage unit 620, a RAM (Random Access Memory) 630, and a ROM (Read Only Memory) 640. The CPU 610 reads various control programs and setting data stored in the ROM 640, stores them in the RAM 630, and executes them to perform various arithmetic processes. Further, the CPU 610 controls the overall operation of the inkjet recording apparatus 1.

[0027] The storage unit 620 stores print jobs (image recording instructions) and print image data (image information) input via the input / output interface 730, and the connecting nozzle positions of the recording heads 3 and 4 generated based on a test chart for detecting the connecting nozzle positions of the heads, which will be described later.

[0028] The conveyance drive unit 710 supplies a drive signal to a conveyance motor based on a control signal supplied from the control unit 600, and conveys the recording material P0 at a predetermined speed and timing. The operation display unit 720 includes a display device such as a liquid crystal display or an organic EL display, and an input device such as an operation key and a touch panel arranged over the screen of the display device. The operation display unit 720 causes the display device to display various information, and supplies an operation signal corresponding to a user's input operation on the input device to the control unit 600. The input / output interface 730 mediates the transmission and reception of data between the external device 800 and the control unit 600. The bus line 740 is a path for transmitting and receiving signals between the control unit 600 and other components.

[0029] FIG. 5 is a block diagram showing the hardware configuration of the head drive unit 20 of the head unit 2. In FIG. 5, for simplicity of the drawing, only one recording head 3 is shown, and the other recording heads are omitted.

[0030] The head drive unit 20 includes drive waveform correction units 21-1 to 21-N corresponding to each of the nozzles 5-1 to 5-N (where "N" is the number of nozzles on the recording head 3) on the recording head 3, a head control unit 22, a basic drive waveform generation unit 23, and a drive waveform correction information storage unit 24.

[0031] The head control unit 22 converts the image data input from the control unit 600 into control signals for each of the nozzles 5-1 to 5-N of each of the recording heads 3 and the recording head 4 of each of the recording units 2K, 2C, 2M, and 2Y. Based on the control signals input from the head control unit 22, the basic drive waveform generation unit 23 generates a basic drive waveform that enables a reference ejection operation according to the image pattern, the conveyance speed, and the printing environment such as temperature, humidity, etc. The drive waveform correction information storage unit 24 stores information indicating the nozzle numbers of the nozzles that require correction and information indicating the correction amounts.

[0032] The drive waveform correction units 21-1 to 21-N correct the basic drive waveform of the drive voltage supplied from the basic drive waveform generation unit 23 based on the correction information read from the drive waveform correction information storage unit 24, and supply it to the respective piezoelectric elements corresponding to the nozzles 5-1 to 5-N. As a result, different ejection characteristics can be given to each of the nozzles 5-1 to 5-N, and appropriate ink ejection is possible from each of the nozzles 5-1 to 5-N.

[0033] In this embodiment, different ejection characteristics are given for each nozzle, but it is not limited thereto. That is, ejection characteristics may be given in units of nozzle rows, or ejection characteristics may be given in units of regions with different pitches. Which unit to give the ejection characteristics can be determined according to constraints such as the memory of the device and the load of the applied voltage.

[0034] FIG. 6 is an explanatory diagram showing an example of a test chart printed on the recording material P0. Each test chart shown in FIGS. 6(a) to 6(f) is obtained by performing image recording (dot ejection) while shifting the nozzle switching position one by one in the overlapping region of the recording head 3 and the recording head 4. In FIG. 6, the open circles indicate the dots formed by the ink ejected from the nozzles of the recording head 3, and the solid black circles indicate the dots formed by the ink ejected from the nozzles of the recording head 4.

[0035] When the nozzle switching position is as shown in the example of FIG. 6(a), the distance between the outermost dot (the rightmost dot in FIG. 6) of the recording head 3 and the outermost dot (the leftmost dot in FIG. 6) of the recording head 4 is too close, and the dot pitch Xa is significantly different from the dot pitch X1 corresponding to the normal region and the dot pitch X2 corresponding to the narrow region. In this case, since the dot density at this nozzle switching position becomes locally high, the image density at the head longitudinal position corresponding to this nozzle switching position locally increases, causing unevenness in the image density in the head longitudinal direction.

[0036] Also, when the nozzle switching position is as shown in the example of FIG. 6(f), the distance between the outermost dot (the rightmost dot in FIG. 6) of the recording head 3 and the outermost dot (the leftmost dot in FIG. 6) of the recording head 4 is too far, and the dot pitch Xf is significantly different from the dot pitch X1 corresponding to the normal region and the dot pitch X2 corresponding to the narrow region. In this case, since the dot density at this nozzle switching position becomes locally low, the image density at the head longitudinal position corresponding to this nozzle switching position locally decreases, and again, unevenness in the image density in the head longitudinal direction is caused.

[0037] Among the examples shown in FIGS. 6(a) to 6(f), the example where the nozzle switching position is as shown in FIG. 6(d) can minimize the deviation from the dot pitch X1 corresponding to the normal region and the dot pitch X2 corresponding to the narrow region. In this case, the dot density at this nozzle switching position becomes approximately the same as the dot density at the locations corresponding to the normal region and the narrow region (within the allowable nozzle pitch), and unevenness in the image density in the head longitudinal direction is suppressed.

[0038] The nozzle switching position where the deviation is minimized is determined, for example, by visually checking a test chart and determining the position where the image density unevenness is judged to be the least. Also, for example, a test chart may be photographed with a scanner or a camera, the captured image may be processed for image processing to measure the dot pitch, and the nozzle switching position where the deviation is minimized may be determined. As a determination condition for the nozzle switching position in this case, a condition of selecting a case where the dot pitch X satisfies X2 < X < X1 can be adopted, but it is not limited to this. For example, a condition of selecting a case where the dot pitch X is closest to the dot pitch X1 in the normal region may be adopted.

[0039] FIG. 7 is an explanatory diagram showing an example of printing a solid image on a recording material P0 after determining the switching position of the nozzles. As shown in FIG. 7(a), when the nozzle switching position in the overlapping region of the recording head 3 and the recording head 4 is determined, the nozzles used for ejection by the recording head 3 and the recording head 4 are set as shown in FIG. 7(b). In this case, in the vicinity of the nozzle switching position (the joint of the heads), as shown in FIG. 7(c), in order from the left, an image portion printed in the normal region (nozzle pitch P1) of the recording head 3, an image portion printed in the narrow region (nozzle pitch P2) of the recording head 3, and an image portion printed in the normal region (nozzle pitch P1) of the recording head 4 are arranged.

[0040] At this time, when a solid image is printed with the same amount of droplet volume (liquid ejection volume) from any of the nozzles 5, the dot pitch X2 of the image portion printed in the narrow region becomes narrower than the dot pitch X1 of the image portion printed in the normal region, the ink coverage rate with respect to the recording material P0 increases, and the image density becomes higher than that in the normal region.

[0041] That is, when a solid image is printed with the same amount of droplet volume (liquid ejection volume) from any of the nozzles 5, even if the narrow region and the normal region with different nozzle pitches are provided to optimize the nozzle switching position and local image density unevenness at the nozzle switching position can be suppressed, a new image density unevenness occurs in which shading occurs between the narrow region and the normal region.

[0042] Therefore, in the present embodiment, the droplet amount (liquid discharge amount) is made different between the nozzle in the narrow region and the nozzle in the normal region, the image density difference between the narrow region and the normal region is reduced, and the above-described new image density unevenness is suppressed.

[0043] Here, generally, the following formula (1) holds between the droplet amount Mj and the droplet velocity Vj.

[0044]

Equation

[0045] In the formula (1), “A” is the nozzle opening area as the nozzle size, “Tc” is the natural vibration period which is the natural vibration characteristic of the pressure chamber communicating with each nozzle, and “k” is a coefficient. From this formula (1), it can be understood that when trying to change the droplet amount Mj while maintaining the droplet velocity Vj, the product of the nozzle opening area A and the natural vibration period Tc may be changed at the same ratio as the droplet amount Mj.

[0046] Note that the present embodiment is an example of realizing the line-type head unit 2 by arranging three liquid discharge head devices 6A, 6B, and 6C in the head longitudinal direction to form the recording units 2K, 2C, 2M, and 2Y having a recording range over the width direction of the recording material P0, but it is not limited thereto. For example, a head unit composed of a single liquid discharge head device 6 may be used. This head unit can realize a scanning-type head unit, for example, by being mounted on a carriage that reciprocates in the width direction (main scanning direction) of the recording material P0.

[0047] Next, the liquid discharge head devices 6A, 6B, and 6C in the present embodiment will be described in more detail. FIG. 8(a) is a perspective view of one liquid discharge head device 6 as seen from the nozzle surface (discharge surface) side, and FIG. 8(b) is a perspective view of one liquid discharge head device 6 as seen from the side opposite to the nozzle surface. FIG. 9 is an explanatory view showing the nozzle surface of the liquid discharge head device 6.

[0048] In addition to the two recording heads 3 and 4, the liquid ejection head device 6 of the present embodiment includes a holding plate 61 as a head holding member for holding these recording heads 3 and 4, a device main body portion 64, and the like.

[0049] In the device main body portion 64, components of each recording head 3 and 4 (such as a flow path member and a piezoelectric element) and a head drive unit 20 are disposed inside, and a connector 69a for connecting a transmission line between the head drive unit 20 and a control unit 600, an ink port 69b for supplying ink, and the like are provided.

[0050] FIG. 10 is a schematic view when the holding plate 61 holding the two recording heads 3 and 4 is viewed from the nozzle surface side. The holding plate 61 is a plate-like member that holds the two recording heads 3 and 4 such that the two recording heads 3 and 4 are displaced from each other in the head short side direction (the vertical direction in FIG. 10), and a part of each nozzle row of the two recording heads 3 and 4 overlaps in the head long side direction (the left-right direction in FIG. 10).

[0051] The two recording heads 3 and 4 are fitted into respective fitting holes formed in the holding plate 61. Head flanges 3a, 3b, 4a, and 4b are provided at each end in the head long side direction of each recording head 3 and 4. By fastening the head flanges 3a, 3b, 4a, and 4b to the holding plate 61 with head fixing screws 63a, 63b, 64a, and 64b, which are screw fastening members as head fixing members, the two recording heads 3 and 4 are fixed to the holding plate 61.

[0052] The plate shape of the holding plate 61 may be a general rectangular shape, but in the present embodiment, as shown in FIG. 10, it has a stepped shape along the outer peripheries of the two recording heads 3 and 4 arranged in steps. That is, in the holding plate 61 of the present embodiment, notches 65 and 65 shown by broken lines in the figure are respectively formed in regions facing each other from the head long side direction at the head long side direction ends on the side where the nozzle row overlapping portions (nozzle row overlapping parts) of the respective recording heads 3 and 4 are located.

[0053] In addition, since the holding plate 61 has such a stepped shape, it is possible to reduce costs and weight by reducing the material of the liquid ejection head device 6. In addition, since the holding plate 61 has such a stepped shape, as described above, when arranging a part of each nozzle row so as to overlap each other in the two recording heads 3 and 4 straddling between two adjacent liquid ejection head devices 6A, 6B, and 6C, as shown in FIG. 1, it is not necessary to displace two adjacent liquid ejection head devices 6A, 6B, and 6C in the short head direction with respect to each other. Therefore, the dimension in the short head direction (recording medium conveyance direction) of the recording units 2K, 2C, 2M, and 2Y of each color can be reduced.

[0054] The holding plate 61 of the present embodiment is made of an inexpensive material (a material that expands and contracts more easily than the mount 2a and the recording heads 3 and 4) that easily expands and contracts due to temperature changes such as the transport environment and use environment of the head, for the purpose of cost reduction and the like. Specifically, as the inexpensive holding plate 61, for example, a stainless steel (such as SUS430) having a large linear expansion coefficient can be adopted.

[0055] However, in the configuration as shown in FIG. 11, when the holding plate 61' expands or contracts due to temperature changes or the like, each end side portion 61c, 61d of the holding plate 61' facing the cutouts 65, 65 of the holding plate 61' is displaced as indicated by the white arrow R in FIG. 11. Then, due to the displacement caused by this expansion or contraction, the end portions (head flanges 3b, 4a) of the recording heads 3 and 4 fixed to the holding plate 61' by the head fixing screws 63a, 63b, 64a, and 64b are displaced. As a result, the recording heads 3 and 4 are pulled or compressed in the head longitudinal direction, and the nozzle positions within the nozzle row overlapping portion (overlap region) of each recording head 3 and 4 are displaced. As a result, a relative displacement of the nozzles occurs between the two recording heads 3 and 4, and a nozzle pitch outside the allowable range occurs in the nozzle row overlapping portion (the joint portion between the recording heads 3 and 4).

[0056] Specifically, as shown in FIG. 11, mounting flanges 61a and 61b' are integrally provided at both ends of the holding plate 61' in the head longitudinal direction. The holding plate 61' is fastened to the mount 2a (see FIG. 1), which is a base member serving as the base of the structure of the liquid ejection head device 6, by mount screws 66a and 66b, which are also screw fastening members constituting the base mounting member, and are fixed to the mount 2a. Since the mounting flanges 61a and 61b' (the fixed portions) of the holding plate 61 fixed to the mount 2a by the mount screws 66a and 66b or the vicinity thereof are constrained by the mount 2a, displacement is suppressed even if the holding plate 61 expands or contracts.

[0057] On the other hand, the end side portions 61c and 61d located on the opposite side of the head longitudinal direction with respect to the mounting flanges 61a and 61b' of the holding plate 61' or the vicinity thereof are not fixed to the mount 2a and are far from the portions (mounting flanges 61a and 61b') fixed by the mount screws 66a and 66b, so they are not constrained by the mount 2a. Therefore, when the holding plate 61' expands or contracts due to a temperature change or the like, the end side portions 61c and 61d of the holding plate 61' will be displaced in the head longitudinal direction as indicated by the white arrow R in FIG. 11.

[0058] Therefore, when the holding plate 61' expands or contracts, among the head flanges 3a, 3b, 4a, 4b of the two recording heads 3, 4 held by the holding plate 61', the head flanges 3a, 4b located near the mount flanges 61a, 61b' of the holding plate 61' have their displacements suppressed, while the head flanges 3b, 4a located near the end side portions 61c, 61d of the holding plate 61' (locations far from the head flanges 3a, 4b) are displaced in the head longitudinal direction as indicated by the black arrows S in FIG. 11. Since the end portions on the head flange 3b, 4a sides of the respective recording heads 3, 4 that are displaced in this way are on the side where the nozzle row overlapping portions of the two recording heads 3, 4 are located, a relative positional shift of the nozzles within the nozzle row overlapping portion occurs between the two recording heads 3, 4, resulting in a nozzle pitch that is outside the allowable range.

[0059] Therefore, in the present embodiment, one of the mount flanges 61a, 61b for attaching both end portions of the holding plate 61 to the mount 2a, i.e., the first mount flange 61a as the first base attachment member, fixes and attaches one end portion of the holding plate 61 to the mount 2a with a mount screw 66a. On the other hand, the other second mount flange 61b, which is the other second base attachment member, attaches the other end portion of the holding plate 61 to the mount 2a while restricting displacement in the head short direction (the vertical direction in FIG. 10) and enabling displacement in the head longitudinal direction (the left - right direction in FIG. 10) with respect to the mount 2a due to the expansion or contraction of the holding plate 61.

[0060] Specifically, the second mount flange 61b is configured separately from the holding plate 61. A hole portion 61e extending in the head longitudinal direction is formed as an engaged portion at the other end portion of the holding plate 61, and the second mount flange 61b fixed to the mount 2a by the second mount flange 61b is provided with a pin 61f as an engaging portion that is slidably inserted into the hole portion 61e.

[0061] With this configuration, when the holding plate 61 expands or contracts, the hole 61e at the other end of the holding plate 61 and the second mounting flange 61b slide relative to each other along the head longitudinal direction, so that the other end of the holding plate 61 can be displaced. As a result, when the holding plate 61 expands or contracts, the holding plate 61 as a whole displaces toward the other end side of the holding plate 61 with reference to the first mounting flange 61a that is integrally provided on the holding plate 61 and fixed to the mount 2a, as shown by the white arrow R' in FIG. 12. As a result, the nozzle row joint portions of the two recording heads 3 and 4 held by the holding plate 61 are all displaced by substantially the same amount in the same direction S', and nozzle relative position deviation between the two recording heads 3 and 4 at the nozzle row joint portion is suppressed from occurring. Therefore, according to the present embodiment, it is possible to suppress the occurrence of a nozzle pitch outside the allowable range at the nozzle row joint portion.

[0062] The play between the pin 61f of the second mounting flange 61b and the hole 61e of the holding plate 61 is desirably made as small as possible in order to suppress displacement (misalignment) of the holding plate 61 in the head width direction. On the other hand, if this play is too small, the sliding resistance between the pin 61f and the hole 61e becomes too large, and there is a possibility that the holding plate 61 cannot be displaced in the head longitudinal direction with respect to the mount 2a when the holding plate 61 expands or contracts. The play between the pin 61f of the second mounting flange 61b and the hole 61e of the holding plate 61 is appropriately set in consideration of these factors.

[0063] Further, in order to suppress the play between the pin 61f of the second mounting flange 61b and the hole 61e of the holding plate 61, as shown in FIG. 13, a spring 67 may be provided as biasing means for biasing the other end of the holding plate 61 in the short head direction. According to this, inside the hole 61e formed at the other end of the holding plate 61, the state where the pin 61f of the second mounting flange 61b is offset in the short head direction can be maintained, and play can be suppressed. The biasing force by this spring 67 needs to be set so that the sliding resistance between the pin 61f and the hole 61e does not become too large and the holding plate 61 does not become unable to be displaced in the longitudinal head direction with respect to the mount 2a when the holding plate 61 expands or contracts.

[0064] Further, the pin 61f of the second mounting flange 61b has a cylindrical shape with a circular cross-sectional shape (a cross-section orthogonal to the longitudinal direction of the pin (= longitudinal head direction)), but is not limited to this. For example, the pin 61f may have a cross-sectional shape capable of preventing rotation around an axis extending in the longitudinal head direction, such as the D-cut shape shown in FIG. 14, and the hole 61e may have a cross-sectional shape corresponding to the cross-sectional shape of this pin 61f. According to this, rotation of the holding plate 61 around an axis extending in the longitudinal head direction can be prevented. Note that the cross-sectional shape capable of preventing rotation around an axis extending in the longitudinal head direction is not limited to the D-cut shape as described above, and may be other cross-sectional shapes such as an oval shape.

[0065] Next, another example of the apparatus for discharging a liquid according to the present invention will be described with reference to FIGS. 15 and 16. FIG. 15 is a plan explanatory view of the main part of the apparatus, and FIG. 16 is a side explanatory view of the main part of the apparatus. This device is a serial type device. By the main scanning movement mechanism 493, the carriage 403 reciprocates in the main scanning direction. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is bridged between the left and right side plates 491A and 491B and holds the carriage 403 movably. Then, by the main scanning motor 405, the carriage 403 is reciprocated in the main scanning direction via the timing belt 408 bridged between the drive pulley 406 and the driven pulley 407.

[0066] This carriage 403 is equipped with a liquid discharge unit 440 that integrates the liquid discharge head device 404 and the head tank 441 according to the present invention. The liquid discharge head device 404 of the liquid discharge unit 440 is the same as the head unit 2 of the above-described embodiment. For example, it includes a recording unit that discharges liquids of each color such as yellow (Y), cyan (C), magenta (M), and black (K). Also, the recording units of each color in the liquid discharge head device 404 are the same as the recording units 2K, 2C, 2M, 2Y of the above-described embodiment. The recording heads 3 and 4 each having a nozzle row composed of a plurality of nozzles are arranged in a staggered manner, and the direction of the nozzle row is along the sub-scanning direction (head longitudinal direction) orthogonal to the main scanning direction, and the discharge direction is downward.

[0067] By a supply mechanism 494 for supplying the liquid stored outside the liquid discharge head device 404 to the liquid discharge head device 404, the liquid stored in the liquid cartridge 450 is supplied to the head tank 441.

[0068] The supply mechanism 494 is composed of a cartridge holder 451 which is a filling part for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, etc. The liquid cartridge 450 is detachably mounted on the cartridge holder 451. The liquid in the liquid cartridge 450 is fed to the head tank 441 by the liquid feeding unit 452 via the tube 456.

[0069] This device is provided with a conveyance mechanism 495 for conveying the paper 410. The conveyance mechanism 495 includes a conveyance belt 412 which is a conveyance means, and a sub-scanning motor 416 for driving the conveyance belt 412.

[0070] The conveyance belt 412 adsorbs the paper 410 and conveys it at a position facing the liquid ejection head device 404. This conveyance belt 412 is an endless belt and is stretched between a conveyance roller 413 and a tension roller 414. The adsorption can be performed by electrostatic adsorption, air suction, or the like.

[0071] Then, the conveyance belt 412 moves circularly in the sub-scanning direction by the conveyance roller 413 being rotationally driven via a timing belt 417 and a timing pulley 418 by the sub-scanning motor 416.

[0072] Furthermore, on one side of the carriage 403 in the main scanning direction, a maintenance and recovery mechanism 420 for maintaining and recovering the liquid ejection head device 404 is arranged on the side of the conveyance belt 412.

[0073] The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 for capping the nozzle surface (the surface on which the nozzles are formed) of the liquid ejection head device 404, a wiper member 422 for wiping the nozzle surface, and the like.

[0074] The main scanning movement mechanism 493, the supply mechanism 494, the maintenance and recovery mechanism 420, and the conveyance mechanism 495 are attached to a housing including side plates 491A, 491B, and a back plate 491C.

[0075] In this device configured as described above, the paper 410 is fed onto the conveyance belt 412 and adsorbed, and the paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 412.

[0076] Therefore, while moving the carriage 403 in the main scanning direction, the liquid ejection head device 404 is driven according to an image signal, so that liquid is ejected onto the stopped paper 410 to form an image.

[0077] Thus, since this apparatus includes the liquid ejection head according to the present invention, a high-quality image can be stably formed.

[0078] Next, another example of the liquid ejection unit according to the present invention will be described with reference to FIG. 17. FIG. 17 is a plan explanatory view of the main part of the unit.

[0079] This liquid ejection unit includes a housing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid ejection head device 404 among the members constituting the apparatus for ejecting the liquid.

[0080] Note that a liquid ejection unit can also be configured in which at least one of the above-described maintenance and recovery mechanism 420 and supply mechanism 494 is further attached to, for example, the side plate 491B of this liquid ejection unit.

[0081] Next, still another example of the liquid ejection unit according to the present invention will be described with reference to FIG. 18. FIG. 18 is a front explanatory view of the unit.

[0082] This liquid ejection unit includes a liquid ejection head device 404 to which a flow path component 444 is attached and a tube 456 connected to the flow path component 444.

[0083] Note that the flow path component 444 is disposed inside a cover 442. A head tank 441 can also be included instead of the flow path component 444. Further, a connector 443 for making an electrical connection with the liquid ejection head device 404 is provided above the flow path component 444.

[0084] In the present application, the "device for discharging a liquid" includes a liquid discharge head, a liquid discharge head device, or a liquid discharge unit, and is a device that drives the liquid discharge head to discharge a liquid. The device for discharging a liquid includes not only a device capable of discharging a liquid onto an object to which the liquid can adhere, but also a device capable of discharging a liquid into the air or into a liquid.

[0085] This "device for discharging a liquid" can also include means related to the feeding, conveyance, and paper discharge of an object to which the liquid can adhere, as well as other pretreatment devices, post-treatment devices, and the like.

[0086] For example, as the "device for discharging a liquid", there are an image forming device that discharges ink to form an image on a sheet of paper, and a three-dimensional modeling device (three-dimensional shaping device) that discharges a shaping liquid onto a powder layer formed in a layer of powder in order to model a three-dimensional object (three-dimensional shaped object).

[0087] Also, the "device for discharging a liquid" is not limited to those in which a significant image such as characters or figures is visualized by the discharged liquid. For example, those that form a pattern or the like that has no meaning by itself, and those that model a three-dimensional image are also included.

[0088] The "object to which the liquid can adhere" means an object to which the liquid can adhere at least temporarily, and includes those that adhere and adhere firmly, those that adhere and penetrate, and the like. Specific examples include recording materials such as paper, recording paper, recording sheets, films, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, media such as inspection cells, and unless otherwise particularly limited, all objects to which the liquid can adhere are included.

[0089] The material of the "object to which the liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and floor materials, textile for clothing, etc., as long as the liquid can adhere even temporarily.

[0090] In addition, "liquid" includes ink, processing liquid, DNA sample, resist, pattern material, binder, modeling liquid, or solutions and dispersions containing amino acids, proteins, calcium, etc.

[0091] In addition, as for the "device for discharging liquid", there is a device in which a liquid discharge head and an object to which the liquid can adhere move relatively, but it is not limited thereto. Specific examples include a serial type device that moves the liquid discharge head and a line type device that does not move the liquid discharge head.

[0092] In addition, as the "device for discharging liquid", there are also a processing liquid coating device that discharges a processing liquid onto paper for the purpose of modifying the surface of the paper, an injection granulation device that injects a composition liquid in which raw materials are dispersed in a solution through a nozzle to granulate fine particles of the raw materials, and the like.

[0093] The "liquid discharge unit" is an integrated unit of functional components and mechanisms with a liquid discharge head, and is an assembly of components related to the discharge of liquid. For example, the "liquid discharge unit" includes at least one of the configurations of a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism combined with a liquid discharge head.

[0094] Here, integration includes, for example, those in which a liquid discharge head and functional components and mechanisms are fixed to each other by fastening, adhesion, engagement, etc., and those in which one is movably held with respect to the other. Also, the liquid discharge head and functional components and mechanisms may be configured to be detachable from each other.

[0095] For example, as a liquid discharge unit, there is one in which a liquid discharge head and a head tank are integrated, like the liquid discharge unit 440 shown in FIG. 16. Also, there are those in which they are connected to each other by a tube or the like and the liquid discharge head and the head tank are integrated. Here, a unit including a filter can also be added between the head tank and the liquid discharge head of these liquid discharge units.

[0096] In addition, as a liquid ejection unit, there is one in which a liquid ejection head and a carriage are integrated.

[0097] In addition, as a liquid ejection unit, there is one in which a liquid ejection head is movably held by a guide member that forms part of a scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated. Also, as shown in FIG. 17, as a liquid ejection unit, there is one in which a liquid ejection head, a carriage, and a main scanning movement mechanism are integrated.

[0098] In addition, as a liquid ejection unit, there is one in which a cap member that is part of a maintenance and recovery mechanism is fixed to a carriage to which a liquid ejection head is attached, and the liquid ejection head, the carriage, and the maintenance and recovery mechanism are integrated.

[0099] In addition, as a liquid ejection unit, as shown in FIG. 18, there is one in which a tube is connected to a liquid ejection head to which a head tank or a flow path component is attached, and the liquid ejection head and a supply mechanism are integrated.

[0100] The main scanning movement mechanism shall include a single guide member. Also, the supply mechanism shall include a single tube and a single loading unit.

[0101] In addition, the "liquid ejection head" is not limited to the actuator used. For example, in addition to the piezoelectric element (a stacked piezoelectric element may be used) as described in the above embodiment, a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator including a diaphragm and a counter electrode, etc. may be used.

[0102] In addition, in the terms of the present application, image formation, recording, printing, imprinting, printing, shaping, etc. are all synonymous.

[0103] Finally, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. Each of these novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Such embodiments and modifications of the embodiments are included in the scope and gist of the invention and are also included in the invention described in the claims and the equivalent scope thereof.

[0104] What has been described above is an example, and each of the following aspects has specific effects. [Aspect 1] Aspect 1 is a liquid ejection head device 6 having a plurality of liquid ejection heads (for example, recording heads 3 and 4) each including a nozzle row in which a plurality of nozzles 5 are arranged in the head longitudinal direction, and a head holding member (for example, holding plate 61) that holds the plurality of liquid ejection heads so that the plurality of liquid ejection heads are displaced from each other in the head short direction and the head longitudinal direction. The liquid ejection head device 6 includes a first base attachment member (for example, first mount flange 61a and mount screw 66a) that fixes and attaches one end portion in the head longitudinal direction of the head holding member to a base member (for example, mount 2a), and the other end portion in the head longitudinal direction of the head holding member is attached to the base member so as to be displaceable in the head longitudinal direction with respect to the base member due to expansion or contraction of the head holding member. And a second base attachment member (for example, second mount flange 61b and mount screw 66b). In this type of liquid ejection head device, individual liquid ejection heads are adjusted so that the nozzle pitch at the joint portion of the nozzle row is within an allowable range and fixed to a head holding member. Then, the head holding member to which a plurality of liquid ejection heads are fixed is attached and fixed to the base member by a base attachment member. Here, for the purpose of cost reduction or the like, an inexpensive head holding member that is likely to expand and contract due to temperature changes or the like (a head holding member that is more likely to expand and contract than the base member or the liquid ejection head) may be adopted. In this case, following the displacement of the head holding member due to expansion or contraction, the liquid ejection head fixed to this head holding member is pulled or compressed in the head longitudinal direction. Therefore, conventionally, by fixing both end portions of the head holding member in the head longitudinal direction to the base member by the base attachment member, the displacement of the head holding member due to expansion or contraction is suppressed, and the occurrence of a nozzle pitch outside the allowable range at the nozzle row joint portion is suppressed. However, it has been found that even in a configuration in which both end portions of the head holding member in the head longitudinal direction are fixed to the base member by the base attachment member, a nozzle pitch outside the allowable range may occur at the nozzle row joint portion. Specifically, for the purpose of reducing costs and weight by reducing the material of the head holding member, notches may be formed in unnecessary portions of the head holding member. In this case, for example, in the head holding member, a notch may be formed in a region facing the head longitudinal direction with respect to one end portion in the head longitudinal direction of the liquid ejection head (hereinafter, also simply referred to as "one end portion"). In such a configuration, when the head holding member expands or contracts due to temperature changes or the like, the end edge portion of the head holding member facing the notch is displaced, and following this displacement, one end portion on the notch side of the liquid ejection head is pulled or compressed in the head longitudinal direction. As a result, even in a configuration where both end portions of the head holding member are fixed to the base member by the base attachment member, the nozzle positions of the nozzle rows on the one end portion side of the liquid ejection head are displaced, and a relative positional deviation of the nozzles occurs between two adjacent liquid ejection heads shifted in the head short direction, resulting in a nozzle pitch outside the allowable range at the nozzle row joint portion (the joint portion between the liquid ejection heads). In this aspect, one of the base attachment members (the first base attachment member) that attaches both end portions of the head holding member to the base member fixes and attaches one end portion of the head holding member to the base member. On the other hand, the other (the second base attachment member) attaches the other end portion of the head holding member to the base member so that displacement in the head longitudinal direction with respect to the base member is possible due to expansion or contraction of the head holding member. With such a configuration, when the head holding member expands or contracts, the head holding member is displaced as a whole toward the other end side of the head holding member attached by the second base attachment member, with the one end side of the head holding member fixed to the base member by the first base attachment member as a reference. As a result, the nozzle row joint portions in the two liquid ejection heads held by this head holding member are displaced by substantially the same amount in the same direction, and the occurrence of a relative positional deviation of the nozzles between the two liquid ejection heads at the nozzle row joint portion is suppressed. Therefore, according to this aspect, it is possible to suppress the occurrence of a nozzle pitch outside the allowable range at the nozzle row joint portion.

[0105] [Second Aspect] The second aspect is characterized in that, in the first aspect, the second base mounting member restricts displacement of the other end portion of the head holding member in the head longitudinal direction in the head lateral direction. According to this, the second base mounting member can suppress displacement of the other end portion of the head holding member in the head lateral direction with respect to the base member.

[0106] [Third Aspect] The third aspect is characterized in that, in the second aspect, the second base mounting member includes an engaging portion (for example, pin 61f) that engages with the engaged portion (for example, hole portion 61e) of the head holding member so as to be displaceable in the head longitudinal direction. According to this, a configuration can be easily realized in which the other end portion of the head holding member in the head longitudinal direction can be displaced in the head longitudinal direction with respect to the base member due to expansion or contraction of the head holding member while restricting displacement in the head lateral direction.

[0107] [Fourth Aspect] The fourth aspect is characterized in that, in the third aspect, one of the engaging portion and the engaged portion is a protruding portion (for example, pin 61f), and the other is a hole or groove (for example, hole portion 61e) into which the protruding portion fits. According to this, a configuration can be easily realized in which the other end portion of the head holding member in the head longitudinal direction can be displaced in the head longitudinal direction with respect to the base member due to expansion or contraction of the head holding member while restricting displacement in the head lateral direction.

[0108] [Fifth Aspect] The fifth aspect is characterized in that, in the fourth aspect, the protruding portion protrudes in the head longitudinal direction and has a cross-sectional shape (for example, D-cut shape) that can prevent rotation about an axis extending in the head longitudinal direction, and the hole or groove has a cross-sectional shape corresponding to the cross-sectional shape of the protruding portion and is a sliding hole or sliding groove that slides on the protruding side surface of the protruding portion. According to this, it is possible to prevent the head holding member from rotating about an axis extending in the head longitudinal direction.

[0109] [Sixth Aspect] The sixth aspect is characterized in that, in any one of the third to fifth aspects, it has biasing means (for example, spring 67) for biasing the other end portion of the head holding member in the head longitudinal direction in the head short-side direction. According to this, it is possible to suppress play between the engaged portion of the head holding member and the engaging portion of the second base mounting member.

[0110] [Seventh Aspect] The seventh aspect is characterized in that, in any one of the first to sixth aspects, a notch 65 is formed in a region of the head holding member that faces, in the head longitudinal direction, an end portion (for example, head flange 4a) on one end side in the head longitudinal direction of a liquid ejection head (for example, recording head 4) held in the vicinity of the other end portion (for example, mount flange 61b) in the head longitudinal direction of the plurality of liquid ejection heads. According to this, it is possible to achieve cost reduction and weight reduction of the liquid ejection head device 6 by reducing the material of the head holding member by the amount of the notch formed. However, in a configuration with such a notch, when the head holding member expands or contracts due to temperature changes or the like, the end edge portion of the head holding member facing the notch is displaced. Therefore, in a configuration where both end portions of the head holding member are fixed to the base member, it is impossible to suppress the occurrence of a nozzle pitch outside the allowable range at the nozzle row connection portion. According to this aspect, in such a head holding member in which such a notch is formed, it is possible to suppress the occurrence of a nozzle pitch outside the allowable range at the nozzle row connection portion.

[0111] [Eighth Aspect] The eighth aspect is characterized in that, in any one of the first to seventh aspects, the plurality of liquid ejection heads are held such that a part of each nozzle row of the plurality of liquid ejection heads overlaps with each other in the head longitudinal direction. According to this, the nozzle alignment work at the nozzle row connection part between a plurality of liquid ejection heads becomes easy.

[0112] [Aspect 9] Aspect 9 is an apparatus for ejecting a liquid, characterized by having a liquid ejection head apparatus according to any one of Aspects 1 to 8. According to this aspect, even if the head holding member expands or contracts due to temperature changes or the like, it is possible to provide an apparatus for ejecting a liquid that maintains the nozzle pitch within an allowable range in the overlapping nozzle row portions and improves the liquid ejection quality.

Explanation of Reference Numerals

[0113] 1: Inkjet recording apparatus 2: Head unit 2a: Mount 2K, 2C, 2M, 2Y: Recording unit 3, 4: Recording head 3a, 3b, 4a, 4b: Head flange 5: Nozzle 6: Liquid ejection head apparatus 61, 61': Holding plate 61a: First mount flange 61b, 61b': Second mount flange 61c, 61d: Side end portion 61e: Hole portion 61f: Pin 63a, 63b, 64a, 64b: Head fixing screw 64: Apparatus main body portion 65: Notch 66a, 66b: Mounting screw 67: Spring 403: Carriage 404: Liquid ejection head apparatus 405: Main scanning motor 406: Driving pulley 407: Driven pulley 408: Timing belt 410: Paper 412: Conveyor Belt 413: Conveyor Roller 414: Tension Roller 416: Sub-scanning Motor 417: Timing Belt 418: Timing Pulley 420: Maintenance and Recovery Mechanism 421: Cap Member 422: Wiper Member 440: Liquid Discharge Unit 441: Head Tank 442: Cover 443: Connector 444: Flow Path Component 450: Liquid Cartridge 451: Cartridge Holder 452: Liquid Feeding Unit 456: Tube 491A: Side Plate 491B: Side Plate 491C: Back Plate 493: Main Scanning Movement Mechanism 494: Supply Mechanism 495: Conveyor Mechanism 600: Control Unit 610: CPU 620: Memory Unit 630: RAM 640: ROM 710: Conveyor Driving Unit 720: Operation Display Unit 730: Input / Output Interface 740: Bus Line 800: External Device

Prior Art Documents

Patent Documents

[0114]

Patent Document 1

Claims

1. A plurality of liquid ejection heads each having a nozzle array in which a plurality of nozzles are arranged in the head longitudinal direction, and a head holding member that holds the plurality of liquid ejection heads so that the plurality of liquid ejection heads are displaced from each other in the head short direction and the head longitudinal direction, a liquid ejection head device comprising: a first base attachment member that fixes and attaches one end portion of the head holding member in the head longitudinal direction to a base member; a second base attachment member that attaches the other end portion of the head holding member in the head longitudinal direction to the base member so as to be displaceable in the head longitudinal direction with respect to the base member due to expansion or contraction of the head holding member. A liquid ejection head device characterized by comprising:

2. In the liquid ejection head device according to Claim 1, the second base attachment member is characterized in that the other end portion of the head holding member in the head longitudinal direction restricts displacement in the head short direction. A liquid ejection head device characterized by comprising:

3. In the liquid ejection head device according to Claim 2, the second base attachment member is characterized by comprising an engaging portion that engages with an engaged portion of the head holding member so as to be displaceable in the head longitudinal direction. A liquid ejection head device characterized by comprising:

4. In the liquid ejection head device according to Claim 3, one of the engaging portion and the engaged portion is a protrusion, and the other is a hole or groove into which the protrusion fits. A liquid ejection head device characterized by comprising:

5. In the liquid ejection head device according to Claim 4, the protrusion protrudes in the head longitudinal direction and has a cross-sectional shape that can prevent rotation about an axis extending in the head longitudinal direction, the hole or groove has a cross-sectional shape corresponding to the cross-sectional shape of the protrusion, and is a sliding hole or sliding groove that slides on a protruding side surface of the protrusion. A liquid ejection head device characterized by comprising:

6. In the liquid ejection head device according to any one of Claims 3 to 5, the liquid ejection head device is characterized by having biasing means for biasing the other end portion of the head holding member in the head longitudinal direction in the head short direction.

7. In the liquid ejection head device according to any one of Claims 1 to 5, a notch is formed in a region of the head holding member that faces, in the head longitudinal direction, an end portion on the one end side in the head longitudinal direction of a liquid ejection head held near the other end portion in the head longitudinal direction of the plurality of liquid ejection heads. A liquid ejection head device characterized by comprising:

8. In the liquid discharge head device according to any one of claims 1 to 5, a liquid discharge head device, characterized in that the plurality of liquid discharge heads are held such that a part of each nozzle row of the plurality of liquid discharge heads overlaps with each other in the head longitudinal direction.

9. A device for discharging a liquid, characterized by having the liquid discharge head device according to any one of claims 1 to 5.

Images