Liquid discharge head device, liquid discharge unit, and liquid discharge device

Abstract

To suppress a nozzle pitch deviated out of an allowable range from occurring at a joint portion of a nozzle row between liquid discharge heads adjacently arranged to shift in a transverse direction of the heads.SOLUTION: A liquid discharge head device comprises a plurality of liquid discharge heads 3 and 4 provided with nozzle rows in which a plurality of nozzles 5 are arranged in a longitudinal direction of the heads, and a head holding member 61 holding the plurality of liquid discharge heads so that the heads are positioned to shift from each other in a transverse direction of the heads and in the longitudinal direction of the heads, where the head holding member comprises mounting parts 61a, 61b and 61e which are mounted on a base member. The liquid discharge head device further has a connection member 67 connecting the plurality of liquid discharge heads to each other so that a relative position between the heads is fixed, where the connection member is fixed to one position in the head holding member.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a liquid ejection head device, a liquid ejection unit, 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 so as to be displaced from each other in the head short direction and the head longitudinal direction.

[0003] For example, Patent Document 1 discloses a head configuration (liquid ejection head device) having five printing heads (liquid ejection heads) each having a nozzle row in which a plurality of nozzles are arranged in the head longitudinal direction, and a head frame (head holding member) to which the five printing heads are fixed. In this head configuration, the five printing heads are arranged in a staggered manner so as to be 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 five times that of the nozzle row of one printing head and at a predetermined nozzle pitch (a nozzle pitch within a predetermined allowable range) by a total of five printing heads.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the 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 the liquid ejection heads adjacent to each other and displaced in the head short direction.

Means for Solving the Problems

[0005] In order to solve the above problems, the present invention includes 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 so as to be displaced from each other in the head short direction and the head longitudinal direction. The head holding member is a liquid ejection head device including an attachment portion attached to a base member, and has a connecting member that connects the plurality of liquid ejection heads so that their relative positions are fixed. The connecting member is fixed to one location 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 rows between adjacent liquid ejection heads that are displaced in the head short direction.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Mode 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 is a device for ejecting liquid will be described.

[0009] First, the head unit in this 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 at 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] For the respective color recording units 2K, 2C, 2M, 2Y, three liquid ejection head devices 6A, 6B, 6C each having two recording heads 3, 4 as liquid ejection heads are mounted on a mount 2a (base member) for mounting the head device of the inkjet recording apparatus. 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 short head direction (vertical direction in FIG. 1) and the long head direction (left - right direction in FIG. 1).

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

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

[0014] By arranging the recording heads 3 and 4 in this way in the respective color recording units 2K, 2C, 2M, and 2Y, it is possible to expand the recording range in the head longitudinal direction over the entire recording unit (the range where an image can be recorded by the ink ejected from the nozzles 5). As a result, a recording unit with a recording range spanning 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 ejected from the recording unit (such as the color of the ink), etc. can be arbitrarily set. Therefore, for example, the head unit 2 may be a head unit that includes only the black single recording unit 2K and performs recording in black single color.

[0016] FIG. 2 is an explanatory diagram showing the head arrangement of the recording head 3 and the recording head 4 provided for each recording unit of the head unit 2. The recording head 3 and the recording head 4 have a nozzle array in which a plurality of nozzles 5 are arranged in the head longitudinal direction (for example, a nozzle array composed of 800 nozzles). In the present embodiment, an example in which the nozzle array is one row will be described, but a configuration in which two or more nozzle arrays are arranged side by side in the recording material conveyance direction may also be used. Further, the nozzle array may be arranged such that the direction of the nozzle array 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 liquid ejection head device 6A, 6B, and 6C. On one liquid ejection head device 6A, 6B, or 6C in the present embodiment, one of the two recording heads 3 and 4, i.e., the recording head 3, partially overlaps with the other recording head 4, and a part of each nozzle array overlaps with each other in the head longitudinal direction.

[0018] In the nozzle arrays 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 array is the normal region, but the narrow region is provided only on one end side of the nozzle array. Note that, 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 array 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. By adopting such a configuration, even if the recording heads 3 and 4 are not positioned with high precision, 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 is minimized is determined. Therefore, if the recording heads are 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 portion 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 is minimized may be a position where, for example, after the head unit 2 is assembled and ink is actually ejected, 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 liquid ejection head devices 6A, 6B, and 6C. However, the same also applies to the nozzle switching positions of the two recording heads 3 and 4 that span between two adjacent liquid ejection head devices 6A and 6B.

[0022] Also, in this 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. Thus, the liquid ejection head devices 6A, 6B, and 6C of this 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 example of the nozzle rows of the recording heads 3 and 4 in this embodiment, there are a normal region and a narrow region, but it may also be an example where the entire area of the nozzle row is a normal region with the normal pitch P1.

[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 arranged 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 the respective 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 the respective 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, causing ink to be 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 out 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 commands) and print image data (image information) input via the input / output interface 730, and the connection nozzle positions of the recording head 3 and the recording head 4 generated based on a test chart for detecting the head connection nozzle positions described later.

[0028] The conveyance drive unit 710 supplies a drive signal to the 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 to overlap 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 holding 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 the recording heads 3 and 4 of each of the recording units 2K, 2C, 2M, and 2Y. 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., based on the control signal input from the head control unit 22. The drive waveform correction information holding 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 holding unit 24, and supply it to the respective piezoelectric elements corresponding to the nozzles 5-1 to 5-N. Thereby, different ejection characteristics can be given to the nozzles 5-1 to 5-N individually, and appropriate ink ejection can be performed from each of the nozzles 5-1 to 5-N.

[0033] In addition, in this embodiment, although different ejection characteristics are provided for each nozzle, it is not limited thereto. That is, ejection characteristics may be provided for each nozzle row, or may be provided for each region having a different pitch. Which unit is used to provide the ejection characteristics may be determined according to constraints such as the memory of the apparatus 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 of the test charts 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 dots formed by the ink ejected from the nozzles of the recording head 3, and the solid black circles indicate 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 dot at the outermost end (the right end in FIG. 6) of the recording head 3 and the dot at the outermost end (the left end 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 becomes locally high, causing image density unevenness 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 dot at the outermost end (the right end in FIG. 6) of the recording head 3 and the dot at the outermost end (the left end 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 becomes locally low, and again, image density unevenness in the head longitudinal direction is caused.

[0037] Among the examples shown in FIGS. 6(a) to 6(f), the example shown in FIG. 6(d) of the nozzle switching position 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 (nozzle pitch within the allowable range), and unevenness in 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 it is judged that there is the least unevenness in image density. Also, for example, a test chart may be photographed with a scanner or a camera, the captured image may be subjected to 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 the 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 the case where the dot pitch X is closest to the dot pitch X1 of 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 nozzle switching position. As shown in FIG. 7(a), when the nozzle switching position in the overlap 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, there are arranged 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.

[0040] At this time, when a solid image is printed with the same amount of droplets (liquid discharge amount) 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 compared to the normal region, 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 droplets (liquid discharge amount) from any of the nozzles 5, even if the narrow region and the normal region with different nozzle pitches are provided and the nozzle switching position is optimized to suppress local image density unevenness at the nozzle switching position, 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 amount of droplets (liquid discharge amount) is made different between the nozzles in the narrow region and the nozzles 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 above 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 should be changed at the same ratio as the droplet amount Mj.

[0046] Note that this embodiment is an example of realizing a line-type head unit 2 by arranging three liquid ejection head devices 6A, 6B, and 6C in the head longitudinal direction to form recording units 2K, 2C, 2M, and 2Y having a recording range extending in the width direction of the recording material P0, but it is not limited to this. For example, a head unit composed of a single liquid ejection 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 ejection head devices 6A, 6B, and 6C in this embodiment will be described in more detail. FIG. 8(a) is a perspective view of one liquid ejection head device 6 as viewed from the nozzle surface (ejection surface) side, and FIG. 8(b) is a perspective view of one liquid ejection head device 6 as viewed from the side opposite to the nozzle surface. FIG. 9 is an explanatory diagram showing the nozzle surface of the liquid ejection head device 6.

[0048] The liquid ejection head device 6 of this embodiment includes, in addition to two recording heads 3 and 4, 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 arranged inside, and a connector 69a for connecting a transmission line between the head drive unit 20 and the control unit 600, an ink port 69b for supplying ink, and the like are provided.

[0050] FIG. 10 is a schematic diagram of the holding plate 61 holding two recording heads 3 and 4 as 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 direction (the vertical direction in FIG. 10), and a part of each nozzle row of the two recording heads 3 and 4 overlaps with each other in the head longitudinal direction (the left-right direction in FIG. 10).

[0051] The two recording heads 3 and 4 are held so that the nozzle surfaces are exposed from the openings formed in the holding plate 61. The plate shape of the holding plate 61 may be a general rectangular shape, but the holding plate 61 of the present embodiment has a stepped shape along the outer circumferences of the two recording heads 3 and 4 arranged in steps as shown in FIG. 10. That is, the holding plate 61 has notches 65, 65 shown by broken lines in the drawing respectively formed in the regions facing each other from the head longitudinal direction at the longitudinal ends of the head on the side where the nozzle row portions (nozzle row overlapping portions) overlapping each other of the respective recording heads 3 and 4 are located.

[0052] Since the holding plate 61 has such a stepped shape, it is possible to achieve cost reduction and weight reduction by reducing the material of the liquid ejection head device 6. Also, since the holding plate 61 has such a stepped shape, as described above, when arranging the two recording heads 3 and 4 straddling between two adjacent liquid ejection head devices 6A, 6B, and 6C so that a part of each nozzle row overlaps with each other, as shown in FIG. 1, it is not necessary to shift two adjacent liquid ejection head devices 6A, 6B, and 6C in the head short side direction with respect to each other. Therefore, the dimensions in the head short side direction (recording material conveyance direction) of the recording units 2K, 2C, 2M, and 2Y of each color can be reduced.

[0053] Here, in the configuration of the comparative example shown below, relative positional deviation of the nozzles may occur between the two recording heads 3 and 4 in the liquid ejection head device, and a nozzle pitch outside the allowable range may occur in the nozzle row overlapping portion (joint portion between the recording heads 3 and 4).

[0054] FIG. 11(a) is a schematic view when the holding plate 61 holding the two recording heads 3 and 4 is viewed from the nozzle surface side in the liquid ejection head device 6' according to the comparative example. FIG. 11(b) is a schematic view showing a state before fixing the screw hole 61e, which is a mounting portion provided on the side wall portion (the lower side in FIG. 11) of the holding plate 61, to the mount 2b with the mounting screw 66c in the liquid ejection head device 6' according to the comparative example. FIG. 11(c) is a schematic view showing a state after fixing screw holes 61e in the side wall portion of the holding plate 61 to the mount 2b with mounting screws 66c in the liquid ejection head device 6' according to the comparative example.

[0055] In the liquid ejection head device 6' according to the comparative example, head flanges 3a, 3b, 4a, and 4b are provided at both longitudinal ends of each of the recording heads 3 and 4 in the head longitudinal direction, as shown in FIG. 11(a). In the configuration of the comparative example, the two recording heads 3 and 4 are fixed to the holding plate 61 by fastening the respective 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. At this time, the individual recording heads 3 and 4 are adjusted so that the nozzle pitch at the joint portion of the nozzle rows is within an allowable range, and are fixed to the holding plate 61 by the head fixing screws 63a, 63b, 64a, and 64b.

[0056] Here, as shown in FIGS. 11(b) and (c), an example is given in which three screw holes 61e arranged in the bed longitudinal direction provided in the side wall portion (the lower side in FIG. 11) of the holding plate 61 are fixed to the mount 2b with three mounting screws 66c. Note that this mount 2b is a base member for attaching the head device of the inkjet recording apparatus, and is different from the mount 2a shown in FIG. 1. Specifically, the mount 2b is a mount to which the screw holes 61e in the side wall portion of the holding plate 61 of the liquid ejection head device are attached, while the mount 2a is a mount to which mount flanges 61a and 61b provided at both longitudinal ends of the holding plate 61 of the liquid ejection head device in the head longitudinal direction are attached.

[0057] In this example, when the mount 2b has low flatness (for example, when it is curved as shown in FIGS. 11(b) and (c)), when the holding plate 61 is fixed to the mount 2b, as shown in FIG. 11(c), the holding plate 61 may be deformed (curved, etc.) following the shape (curvature, etc.) of the mount 2b.

[0058] When such deformation occurs in the holding plate 61, the displacement amounts at each point on the holding plate 61 are different. Therefore, as in the liquid ejection head device 6' of the comparative example, if two recording heads 3 and 4 are fixed to different positions on the holding plate 61 by head fixing screws 63a, 63b, 64a, and 64b respectively, a relative positional deviation of the nozzles occurs between the recording heads 3 and 4. As a result, a nozzle pitch that is out of the allowable range may occur at the joint portion of the nozzle rows between the recording heads 3 and 4.

[0059] Specifically, as shown in FIG. 11(c), when the holding plate 61 is curved following the curvature of the mount 2b, the position farther from the mount 2b deforms more greatly than the position closer to the mount 2b. Therefore, the recording head 4 farther from the mount 2b is displaced more greatly than the recording head 3 closer to the mount 2b. As a result, a relative positional deviation of the nozzles occurs between the recording heads 3 and 4, and a nozzle pitch that is out of the allowable range may occur at the joint portion of the nozzle rows between the recording heads 3 and 4.

[0060] Note that the problem that a nozzle pitch that is out of the allowable range occurs at the joint portion of the nozzle rows between the recording heads 3 and 4 due to the holding plate 61 deforming following the shape of the base member (mount 2b) is not limited to the above configuration. For example, the same applies to an example (see FIG. 1) in which mount flanges 61a and 61b, which are attachment portions provided at each end of the holding plate 61 in the head longitudinal direction, are fixed to the mount 2a as the base member by mount screws 66a and 66b.

[0061] In addition, for the purpose of cost reduction, etc., the holding plate 61 may be made of an inexpensive material (a material that expands and contracts more easily than the mounts 2a and 2b and the recording heads 3 and 4) that expands and contracts easily due to temperature changes such as the transportation environment and use environment of the head. Specifically, as an inexpensive holding plate 61, for example, a stainless steel (such as SUS430) having a large linear expansion coefficient may be adopted.

[0062] Also in this case, for example, in the comparative example, when the mounting flanges 61a and 61b of the holding plate 61 are fixed to the mount 2a by the mounting screws 66a and 66b (see FIG. 1), there is a possibility that a nozzle pitch outside the allowable range may occur at the joint portion between the recording heads 3 and 4.

[0063] Specifically, when the holding plate 61 expands or contracts due to a temperature change or the like, since the mounting flanges 61a and 61b at both ends of the holding plate 61 in the head longitudinal direction are fixed to the mount 2a, as shown in FIG. 12, each end side portion 61c, 61d of the holding plate 61 facing the notches 65, 65 of the holding plate 61 is displaced as shown by the white arrow R in FIG. 12. Then, due to the displacement caused by this expansion or contraction, the ends (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, 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, 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 (joint portion between the recording heads 3 and 4).

[0064] Therefore, in the present embodiment, as shown by the two-dot chain line in FIG. 10, a connecting member 67 for connecting the two recording heads 3 and 4 so that their relative positions are fixed is provided, and by fixing this connecting member 67 to a portion of the holding plate 61 with a fixing screw 68, the two recording heads 3 and 4 are held by the holding plate 61.

[0065] FIG. 13 is a schematic diagram showing the connecting member 67 that connects the two recording heads 3 and 4 so that their relative positions are fixed in the present embodiment. In this embodiment, the individual recording heads 3 and 4 are adjusted so that the nozzle pitch at the joint portion of the nozzle rows is within an allowable range, and are fixed to the connecting member 67 with the head fixing screws 63c and 64c. In this embodiment, the ends in the head longitudinal direction on the closer sides of two recording heads 3 and 4 that are displaced in the head short-side direction and adjacent to each other, that is, the ends on the side of the overlapping portion of the respective nozzle rows (the joint portion between the recording heads 3 and 4), are connected by the connecting member 67.

[0066] The locations on each of the recording heads 3 and 4 connected by the connecting member 67 may be any locations on each of the recording heads 3 and 4. However, if the connection is made with the connecting member 67 at a location close to the overlapping portion of the nozzle rows (the joint portion between the recording heads 3 and 4), it is easy to adjust the nozzle pitch at the joint portion of the nozzle rows.

[0067] Also, if the connection is made with the connecting member 67 at a location close to the overlapping portion of the nozzle rows, even if a location other than the location connected by the connecting member 67 is displaced by some external force, the relative displacement between the recording heads 3 and 4 in the overlapping portion of the nozzle rows is suppressed by the restraining force of the connecting member 67. Therefore, even in such a case, it is possible to suppress the occurrence of a nozzle pitch that is out of the allowable range in the overlapping portion of the nozzle rows (the joint portion between the recording heads 3 and 4).

[0068] According to this embodiment, the connecting member 67 is fixed at one location of the holding plate 61 by the fixing screw 68 through the fixing hole 67a provided at one location of the connecting member 67. Therefore, as shown in FIGS. 14(a) and (b), even if the holding plate 61 is deformed (curved) following the shape (curvature, etc.) of the mount 2b, the connecting member 67 does not deform.

[0069] Specifically, if the connecting member 67 is fixed at two or more locations on the holding plate 61, when the holding plate 61 deforms, the relative positions between the respective fixing points of the connecting member 67 on the holding plate 61 shift, and as a result, the connecting member 67 deforms following the deformation of the holding plate 61. On the other hand, if the connecting member 67 is fixed at one location on the holding plate 61 as in the present embodiment, when the holding plate 61 deforms, even if the position of the connecting member 67 is displaced, the connecting member 67 does not deform.

[0070] This is the same even when the holding plate 61 expands or contracts (deforms) due to temperature changes or the like. That is, when the holding plate 61 expands or contracts (deforms) due to temperature changes or the like, even if the position of the connecting member 67 is displaced, the connecting member 67 does not deform.

[0071] As described above, in the present embodiment, as shown in FIG. 14(b), even when the holding plate 61 deforms, the connecting member 67 does not deform. Therefore, the displacement of the relative position between the two recording heads 3 and 4 connected so that their relative positions are fixed by this connecting member 67 is suppressed. Accordingly, 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 rows between the two adjacent recording heads 3 and 4 that are displaced in the short head direction.

[0072] In the present embodiment, a configuration may be adopted in which the recording heads 3 and 4 held on the holding plate 61 via the connecting member 67 are further held on the holding plate 61 at another location (a location other than the connecting member 67). For example, among the respective end portions in the head longitudinal direction of each of the recording heads 3 and 4, the end portions on the side opposite to the end portions fixed to the connecting member 67 by the head fixing screws 63c and 64c may be fixed to the holding plate 61 by the head fixing screws 63a and 64b, respectively. In this case, the recording heads 3 and 4 are less likely to come off the holding plate 61, which is advantageous in terms of durability and the like.

[0073] However, in this configuration, when the holding plate 61 is deformed, a relative positional deviation occurs between the location where the holding plate 61 is connected to the connecting member 67 in each of the recording heads 3, 4 (the locations of the head fixing screws 63c, 64c) and the location where the holding plate 61 is held (the locations of the head fixing screws 63a, 64b), and a force that deforms or displaces each of the recording heads 3, 4 acts. Even in this case, since the connecting member 67 connects between the two recording heads 3, 4 and restrains (fixes) their relative positions as in the present embodiment, the deviation of the relative positions between the two recording heads 3, 4 is suppressed as compared with the configuration without the connecting member 67, and the occurrence of a nozzle pitch that exceeds the allowable range at the joint portion is suppressed.

[0074] On the other hand, in the present embodiment, the two recording heads 3, 4 are configured to be fixed to the holding plate 61 only via the connecting member 67. According to this, even if the holding plate 61 is deformed, the influence of the deformation force on deforming and displacing the two recording heads 3, 4 can be eliminated. Therefore, the effect of suppressing the occurrence of a nozzle pitch that exceeds the allowable range at the joint portion can be improved.

[0075] Also, in the present embodiment, each of the recording heads 3, 4 is fixed to one location of the connecting member 67 by the head fixing screws 63c, 64c, respectively. According to this, compared with a configuration in which each of the recording heads 3, 4 is fixed at two or more locations of the connecting member 67, it is easy to adjust the nozzle pitch at the joint portion of the nozzle rows between the recording heads 3, 4.

[0076] Also, in the present embodiment, the longitudinal end portions of the heads of the recording heads 3, 4 are fixed to the connecting member 67. According to this, there is no need to provide a fixing portion with the connecting member 67 that protrudes in the short head direction of the recording heads 3, 4, so that an increase in size in the short head direction of the recording heads 3, 4 can be suppressed.

[0077] 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 apparatus is a serial type apparatus. 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 spanned 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 spanned between the drive pulley 406 and the driven pulley 407.

[0078] This carriage 403 is equipped with a liquid discharge unit 440 in which the liquid discharge head device 404 and the head tank 441 according to the present invention are integrated. 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, and includes, for example, a recording unit that discharges liquids of each color of yellow (Y), cyan (C), magenta (M), and black (K). Also, the recording units of each color in the liquid discharge head device 404 are arranged in a staggered manner with recording heads 3 and 4 each having a nozzle row composed of a plurality of nozzles, in the same manner as the recording units 2K, 2C, 2M, and 2Y of the above-described embodiment. 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.

[0079] 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.

[0080] 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 is fed from the liquid cartridge 450 to the head tank 441 by the liquid feeding unit 452 via the tube 456.

[0081] This apparatus includes a conveyance mechanism 495 for conveying a sheet 410. The conveyance mechanism 495 includes a conveyance belt 412 as a conveyance means and a sub-scanning motor 416 for driving the conveyance belt 412.

[0082] The conveyance belt 412 adsorbs the sheet 410 and conveys it to 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.

[0083] Then, the conveyance belt 412 moves in a circular motion 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.

[0084] 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.

[0085] The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 for capping the nozzle surface (the surface on which nozzles are formed) of the liquid ejection head device 404, a wiper member 422 for wiping the nozzle surface, and the like.

[0086] 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.

[0087] In this apparatus configured as described above, the sheet 410 is fed onto the conveyance belt 412 and adsorbed, and the sheet 410 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 412.

[0088] Therefore, while moving the carriage 403 in the main scanning direction, the liquid ejection head device 404 is driven according to the image signal, so that liquid is ejected onto the stationary paper 410 to form an image.

[0089] As described above, since this apparatus is provided with the liquid ejection head according to the present invention, a high-quality image can be stably formed.

[0090] Next, another example of the liquid ejection unit according to the present invention will be described with reference to FIG. 17. FIG. 17 is an explanatory plan view of the main part of the unit.

[0091] 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.

[0092] Note that a liquid ejection unit can also be configured by further attaching at least one of the maintenance and recovery mechanism 420 and the supply mechanism 494 described above to, for example, the side plate 491B of this liquid ejection unit.

[0093] 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 an explanatory front view of the unit.

[0094] 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.

[0095] Note that the flow path component 444 is disposed inside the cover 442. Instead of the flow path component 444, a head tank 441 can also be included. Further, a connector 443 for making an electrical connection with the liquid ejection head device 404 is provided above the flow path component 444.

[0096] In this application, the "device for discharging a liquid" is a device that includes a liquid discharge head, a liquid discharge head device, or a liquid discharge unit, and drives the liquid discharge head to discharge the liquid. The device for discharging a liquid includes not only a device capable of discharging the liquid onto an object to which the liquid can adhere, but also a device capable of discharging the liquid into the air or into a liquid.

[0097] This "device for discharging a liquid" can also include means related to the feeding, conveying, and paper discharging of an object to which the liquid can adhere, as well as other pretreatment devices, post-treatment devices, and the like.

[0098] For example, as the "device for discharging a liquid", there are an image forming device that discharges ink to form an image on 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 shape a three-dimensional object (three-dimensional shaped object).

[0099] 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 shape a three-dimensional image are also included.

[0100] The "object to which the liquid can adhere" means an object to which the liquid can adhere at least temporarily, such as an object that adheres and adheres firmly, an object that adheres and penetrates, 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 all objects to which the liquid adheres are included unless otherwise particularly limited.

[0101] 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.

[0102] In addition, the "liquid" includes ink, processing liquid, DNA sample, resist, pattern material, binder, molding liquid, or solutions and dispersions containing amino acids, proteins, calcium, etc.

[0103] In addition, the "device for discharging a liquid" includes, but is not limited to, a device in which a liquid discharge head and an object to which the liquid can adhere move relative to each other. 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.

[0104] In addition, other examples of the "device for discharging a liquid" include a processing liquid coating device that discharges a processing liquid onto paper in order to coat the surface of the paper for the purpose of modifying the surface of the paper, and 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.

[0105] In addition, the "device for discharging a liquid" according to the present invention also includes a manufacturing device for electrodes and electrochemical elements. Hereinafter, the manufacturing device for electrodes will be described.

[0106] FIG. 19 is a schematic diagram showing an example of a manufacturing device for electrodes according to an embodiment of the present invention. The manufacturing device for electrodes is a device that manufactures an electrode including a layer having an electrode material by discharging a liquid composition using a head module including a liquid discharge head device.

[0107] The ejection means included in the electrode manufacturing apparatus shown in FIG. 19 is a head module including the liquid ejection head device 6 according to the above-described embodiments (including modified examples). By ejecting the liquid composition from the recording heads 3 and 4 of the liquid ejection head device 6 included in the head module, the liquid composition is applied onto the object, and a liquid composition layer is formed. The object (hereinafter sometimes referred to as the "ejection object") is not particularly limited as long as it is an object on which a layer containing an electrode material is to be formed, and can be appropriately selected according to the purpose. For example, examples of the object include an electrode substrate (current collector), an active material layer, and a layer containing a solid electrode material. Further, the object may be an electrode mixture layer containing an active material on an electrode substrate (current collector). Further, the ejection means and the ejection process may be means and a process for forming a layer having an electrode material by directly ejecting the liquid composition as long as it is possible to form a layer having an electrode material on the ejection object. Further, the ejection means and the ejection process may be means and a process for forming a layer having an electrode material by indirectly ejecting the liquid composition.

[0108] Other configurations included in the manufacturing apparatus for the electrode mixture layer are not particularly limited and can be appropriately selected according to the purpose. Further, other steps included in the manufacturing method for the electrode mixture layer are also not particularly limited and can be appropriately selected according to the purpose. For example, examples of the configurations and steps included in the manufacturing apparatus and the manufacturing method for the electrode mixture layer include a heating means and a heating step.

[0109] The heating means included in the manufacturing apparatus for the electrode mixture layer is a means for heating the liquid composition ejected by the ejection means. Further, the heating step included in the manufacturing method for the electrode mixture layer is a step for heating the liquid composition ejected in the ejection step. By heating the liquid composition, the liquid composition layer can be dried.

[0110] Here, as an example of the electrode manufacturing apparatus, an electrode manufacturing apparatus for forming an electrode mixture layer containing an active material on an electrode substrate (current collector) will be described. As shown in FIG. 19, the electrode manufacturing apparatus includes a discharge process section 110 that includes a step of applying a liquid composition onto a printing substrate 704 having a discharge target to form a liquid composition layer, and a heating process section 130 that includes a heating step of heating the liquid composition layer to obtain an electrode composite layer.

[0111] The electrode manufacturing apparatus includes a transport section 705 that transports the printing substrate 704. The transport section 705 transports the printing substrate 704 at a preset speed in the order of the discharge process section 110 and the heating process section 130. There is no particular limitation on the method for manufacturing the printing substrate 704 having a discharge target such as an active material layer, and a known method can be appropriately selected. The discharge process section 110 includes a liquid discharge head device 6 that realizes an application step of applying a liquid composition onto the printing substrate 704, a storage container 111 that stores the liquid composition 707, and a supply tube 112 that supplies the liquid composition 707 stored in the storage container 111 to the liquid discharge head device 6.

[0112] In the discharge process section 110, the liquid composition 707 is discharged from the recording heads 3 and 4 of the liquid discharge head device 6, the liquid composition 707 is applied onto the printing substrate 704, and a liquid composition layer is formed in a thin film shape. Note that the storage container 111 may be configured to be integrated with the electrode composite layer manufacturing apparatus, or may be configured to be removable from the electrode composite layer manufacturing apparatus. Further, the storage container 111 may be a storage container integrated with the electrode composite layer manufacturing apparatus, or a container used for adding to a storage container that is removable from the electrode composite layer manufacturing apparatus.

[0113] The storage container 111 and the supply tube 112 can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0114] In the heating engineering department 130, a solvent removal process is performed to heat and remove the solvent remaining in the liquid composition layer. Specifically, the solvent remaining in the liquid composition layer is heated by the heating device 703 of the heating engineering department 130 and dried, whereby the solvent is removed from the liquid composition layer. Thereby, an electrode mixture layer is formed. Further, the solvent removal process in the heating engineering department 130 may be performed under reduced pressure.

[0115] The heating device 703 is not particularly limited and can be appropriately selected according to the purpose. For example, examples of the heating device 703 include substrate heating, an IR heater, a hot air heater, etc. Further, the heating device 703 may be a combination of at least two of substrate heating, an IR heater, and a hot air heater. Also, regarding the heating temperature and heating time, they can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the formed film thickness.

[0116] By using the electrode manufacturing apparatus according to the embodiment of the present invention, the liquid composition can be discharged to the target position of the discharge object. The electrode mixture layer can be suitably used, for example, as a part of the configuration of an electrochemical element. The configuration other than the electrode mixture layer in the electrochemical element is not particularly limited, and known ones can be appropriately selected. For example, examples of the configuration other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, etc.

[0117] The "liquid discharge unit" is an integrated unit of functional components and mechanisms in a liquid discharge head and is an aggregate of components related to liquid discharge. For example, the "liquid discharge unit" includes, for example, a combination of 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 with a liquid discharge head.

[0118] Here, the integration includes, for example, those in which the 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.

[0119] For example, as a liquid ejection unit, there is one in which a liquid ejection head and a head tank are integrated, such as the liquid ejection unit 440 shown in FIG. 16. Also, there is one in which a liquid ejection head and a head tank are integrated by being connected to each other with a tube or the like. Here, a unit including a filter can also be added between the head tank and the liquid ejection head of these liquid ejection units.

[0120] Also, as a liquid ejection unit, there is one in which a liquid ejection head and a carriage are integrated.

[0121] Also, as a liquid ejection unit, there is one in which a liquid ejection head is movably held by a guide member that constitutes a 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.

[0122] Also, as a liquid ejection unit, there is one in which a cap member that is a 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.

[0123] Also, 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.

[0124] The main scanning movement mechanism shall also include a single guide member. Also, the supply mechanism shall include a single tube and a single loading unit.

[0125] In addition, the "liquid ejection head" is not limited to a specific actuator. For example, in addition to the piezoelectric element (which may use a stacked piezoelectric element) as described in the above embodiment, a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator composed of a diaphragm and a counter electrode, etc. may be used.

[0126] Also, in the terms of the present application, imaging, recording, printing, imprinting, printing, shaping, etc. are all regarded as synonyms.

[0127] 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 its equivalent scope.

[0128] 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, 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 as to be displaced from each other in the head short direction and the head longitudinal direction. The head holding member has an attachment portion (for example, mount flanges 61a, 61b and screw holes 61e in the side wall portion) that is attached to a base member (for example, mounts 2a, 2b). The liquid ejection head device 6 has a connecting member 67 that connects the plurality of liquid ejection heads so that their relative positions are fixed, and the connecting member is fixed to one location of the head holding member. 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 are held by a head holding member. Then, the head holding member holding a plurality of liquid ejection heads is attached and fixed to a base member at an attachment portion. Here, when the base member (such as a mount of a device that ejects liquid) to which the head holding member is fixed has low flatness, etc., the head holding member may be deformed following the base member by fixing the head holding member to the base member. For example, when the fixing surface of the base member to which the head holding member is fixed is curved (originally a flat surface), the head holding member may be curved (warped) along the curvature of the fixing surface of the base member. In a conventional liquid ejection head device, a plurality of liquid ejection heads are respectively fixed at different positions of the head holding member. Therefore, when the head holding member is deformed following the base member, the relative position between the liquid ejection heads is displaced, and as a result, a relative displacement of the nozzles occurs between the liquid ejection heads, and a nozzle pitch outside the allowable range may occur at the joint portion of the nozzle row between the liquid ejection heads. Also, for the purpose of cost reduction, etc., an inexpensive head holding member (a head holding member that is more likely to expand and contract due to temperature changes, etc. than the base member or the liquid ejection head) that is likely to expand and contract due to temperature changes, etc. may be adopted. In this case, in a conventional liquid ejection head device, following the deformation of the head holding member due to expansion or contraction, a plurality of liquid ejection heads respectively fixed to this head holding member are pulled or compressed in the head longitudinal direction. As a result, a relative displacement of the nozzles occurs between the liquid ejection heads, and a nozzle pitch outside the allowable range may occur at the joint portion of the nozzle row between the liquid ejection heads. In this aspect, a connecting member is provided to connect a plurality of liquid ejection heads so that their relative positions are fixed, and by fixing this connecting member to one location of the head holding member, the plurality of liquid ejection heads are held by the head holding member. Since the connecting member is fixed at one location of the head holding member, even if the head holding member deforms following the base member or expands or contracts (deforms) due to temperature changes or the like, the connecting member does not deform. Specifically, if the connecting member is fixed at two or more locations of the head holding member, when the head holding member deforms, the relative positions between the respective fixing points of the connecting member on the head holding member are displaced, and as a result, the connecting member deforms following the deformation of the head holding member. On the other hand, when the connecting member is fixed at one location of the head holding member, when the head holding member deforms, the position of the connecting member is displaced, but the connecting member does not deform. Thus, in this aspect, even if the head holding member deforms, the connecting member does not deform, so the displacement of the relative positions between the plurality of liquid ejection heads connected so that their relative positions are fixed by this connecting member is suppressed. Therefore, it is suppressed that a nozzle pitch outside the allowable range occurs at the joint portion of the nozzle rows between the liquid ejection heads adjacent to each other and displaced in the short side direction of the head. Note that this aspect does not exclude a configuration in which the liquid ejection head held by the head holding member via the connecting member is further held by the head holding member at another location (a location other than the connecting member). In such a configuration, since the holding force of the liquid ejection head by the head holding member is increased, it is advantageous in terms of durability and the like. However, in this configuration, when the head holding member deforms, the position of the connecting member is displaced thereby, and a relative position displacement occurs between the location connected to the connecting member and the location held by the head holding member in each liquid ejection head, and a force that deforms or displaces each liquid ejection head acts. Even in this case, according to this aspect, since the connecting member connects between the respective liquid ejection heads, compared with a configuration without the connecting member, the displacement of the relative positions between the plurality of liquid ejection heads is suppressed, and it is suppressed that a nozzle pitch outside the allowable range occurs at the joint portion.

[0129] [Second Aspect] The second aspect is characterized in that, in the first aspect, the plurality of liquid ejection heads are fixed to the head holding member only via the connecting member. According to this, even if the head holding member is deformed, the influence of the deformation force on deforming and displacing the plurality of liquid ejection heads can be eliminated. Therefore, it is possible to improve the effect of suppressing the occurrence of a nozzle pitch that deviates from the allowable range at the joint portion.

[0130] [Third Aspect] The third aspect is characterized in that, in the first or second aspect, the connecting member connects between the head longitudinal ends on the closer side to each other of two liquid ejection heads (for example, recording head 3 and recording head 4) that are displaced in the head lateral direction and adjacent to each other. According to this, since it is possible to connect with the connecting member at a location close to the nozzle row overlapping portion (joint portion) in the two liquid ejection heads, it is easy to adjust the nozzle pitch at the joint portion of the nozzle row. Also, even if, for some reason, a location other than the location connected by the connecting member in the two liquid ejection heads is displaced by an external force, the relative displacement between the two liquid ejection heads in the nozzle row overlapping portion is suppressed by the restraining force of the connecting member. Therefore, it is advantageous for suppressing the occurrence of a nozzle pitch that deviates from the allowable range in the nozzle row overlapping portion (joint portion).

[0131] [Fourth Aspect] The fourth aspect is characterized in that, in any one of the first to third aspects, the connecting member connects such that a part of each nozzle row of two liquid ejection heads that are displaced in the head lateral direction and adjacent to each other overlaps in the head longitudinal direction. According to this, the nozzle alignment work at the nozzle row joint portion between the two liquid ejection heads becomes easy.

[0132] [Fifth Aspect] The fifth aspect is characterized in that, in any one of the first to fourth aspects, the liquid ejection head is fixed to one location of the connecting member. According to this, compared with a configuration in which each liquid ejection head is fixed at two or more locations of the connecting member, it is easier to adjust the nozzle pitch at the joint portion of the nozzle rows between the liquid ejection heads.

[0133] [Sixth Aspect] The sixth aspect is characterized in that, in any one of the first to fifth aspects, an end portion in the head longitudinal direction of the liquid ejection head is fixed to the connecting member. According to this, since there is no need to provide a fixing portion with the connecting member that protrudes in the head lateral direction of the liquid ejection head, it is possible to suppress an increase in size in the head lateral direction of the liquid ejection head.

[0134] [Seventh Aspect] The seventh aspect is characterized in that, in any one of the first to sixth aspects, in the head holding member, a notch 65 is formed in a region facing, from the head longitudinal direction, an end portion on the other end side in the head longitudinal direction of the liquid ejection heads (for example, the recording head 3 and the recording head 4) held in the vicinity of one end portion in the head longitudinal direction (for example, the mount flanges 61a, 61b) of the head holding member. According to this, it is possible to reduce the cost and weight 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 a temperature change or the like, the end edge portion of the head holding member facing the notch is displaced. Therefore, in a configuration in which 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 joint 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 joint portion.

[0135] [Eighth Aspect] The eighth aspect is a liquid ejection unit, characterized by including the liquid ejection head device according to any one of the first to seventh aspects. According to this aspect, even if the head holding member is deformed, it is possible to provide a liquid ejection unit that maintains the nozzle pitch in the overlapping nozzle row portions within an allowable range and improves the liquid ejection quality.

[0136] [Ninth Aspect] The ninth aspect is a device for ejecting a liquid, characterized by including the liquid ejection head device according to any one of the first to seventh aspects, or the liquid ejection unit according to the eighth aspect. According to this aspect, even if the head holding member is deformed, it is possible to provide a device for ejecting a liquid that maintains the nozzle pitch in the overlapping nozzle row portions within an allowable range and improves the liquid ejection quality.

Explanation of Reference Numerals

[0137] 1: Inkjet recording device 2: Head unit 2a, 2b: Mount 3, 4: Recording head 3a, 3b, 4a, 4b: Head flange 5: Nozzle 6, 6': Liquid ejection head device 20: Head drive unit 61: Holding plate 61a, 61b: Mount flange 61e: Screw hole 63a~63c: Head fixing screw 64: Device main body part 64a~64c: Head fixing screw 65: Notch 66a~66c: Mount screw 67: Connecting member 67a: Fixing hole 68: Fixing screw 100: Liquid ejection unit 110: Ejection engineering part 111: Storage container 112: Supply tube 130: Heating engineering department 403: Carriage 404: Liquid ejection head device 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 ejection 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: Conveying mechanism 600: Control unit 610: CPU 620: Memory unit 630: RAM 640: ROM 703: Heating device 704: Printing substrate 705: Conveying section 707: Liquid composition 710: Conveying drive section 720: Operation display unit 730: Input / output interface 740: Bus line 800: External device

Prior art documents

Patent documents

[0138]

Patent Document 1

Claims

1. 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 so as to be displaced from each other in the head lateral direction and the head longitudinal direction, wherein the head holding member is a liquid ejection head device including an attachment portion attached to a base member, the liquid ejection head device having a connecting member that connects the plurality of liquid ejection heads so that their relative positions are fixed to each other, and the connecting member is fixed to one location of the head holding member.

2. In the liquid ejection head device according to Claim 1, the plurality of liquid ejection heads are fixed to the head holding member only via the connecting member.

3. In the liquid ejection head device according to Claim 1 or 2, the connecting member connects between end portions in the head longitudinal direction on the closer sides of two liquid ejection heads that are displaced in the head lateral direction and adjacent to each other.

4. In the liquid ejection head device according to Claim 1 or 2, the connecting member connects two liquid ejection heads that are displaced in the head lateral direction and adjacent to each other such that a part of each nozzle array overlaps in the head longitudinal direction.

5. In the liquid ejection head device according to Claim 1 or 2, the liquid ejection head is fixed to one location of the connecting member.

6. In the liquid ejection head device according to Claim 1 or 2, end portions in the head longitudinal direction of the liquid ejection head are fixed to the connecting member.

7. In the liquid ejection head device according to Claim 1 or 2, a notch is formed in a region of the head holding member that faces, in the head longitudinal direction, an end portion on the other end side in the head longitudinal direction of a liquid ejection head held near one end portion in the head longitudinal direction of the head holding member.

8. A liquid ejection unit including the liquid ejection head device according to Claim 1 or 2.

9. A device for ejecting a liquid, comprising the liquid ejection head device according to Claim 1, or the liquid ejection unit according to Claim 8.

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