JP7794992B2 - Liquid ejection head and liquid ejection device - Google Patents

Description

The disclosed embodiments relate to a liquid ejection head and a liquid ejection device.

Inkjet printers and inkjet plotters are well-known printing devices that use the inkjet recording method. These inkjet printing devices are equipped with a liquid ejection head that ejects liquid.

One such liquid ejection head is known to be fixed to a conductive frame and grounded.

Japanese Patent Application Laid-Open No. 2006-102984

A liquid ejection head according to one aspect of the embodiment comprises a first flow path member, a second flow path member, and a conductive portion. The first flow path member is conductive and has a nozzle that ejects liquid. The second flow path member supplies the liquid to the first flow path member. The conductive portion has a positioning mechanism that determines the position of the nozzle. The conductive portion is electrically conductive with the first flow path member and has a higher conductivity than the second flow path member.

FIG. 1 is a front view that schematically shows the front of a printer according to an embodiment. FIG. 2 is a plan view that schematically shows a general plane of the printer according to the embodiment. FIG. 3 is a perspective view illustrating an example of a liquid ejection head according to an embodiment. FIG. 4A is an enlarged perspective view of region IV shown in FIG. FIG. 4B is a perspective view of region IV shown in FIG. 3 as seen from another direction. FIG. 5A is an enlarged perspective view of region V shown in FIG. FIG. 5B is a perspective view of the region V shown in FIG. 3 as viewed from another direction. FIG. 6 is a cross-sectional view illustrating an example of a liquid ejection head according to an embodiment. FIG. 7 is a perspective view showing an example of a second flow path member included in the liquid ejection head according to the embodiment. FIG. 8 is a perspective view showing an example of a state in which a grounding member is installed on the second flow path member shown in FIG. FIG. 9 is a cross-sectional view illustrating an example of a liquid ejection head according to an embodiment. FIG. 10 is a cross-sectional view showing another example of a liquid ejection head according to an embodiment. FIG. 11 is a perspective view illustrating an example of a conductive member according to the embodiment.

The liquid ejection head described above had room for further improvement in terms of achieving stable ground contact.

Therefore, it is expected that a liquid ejection head and a liquid ejection device that can be stably grounded will be provided.

Embodiments of the liquid ejection head and liquid ejection device disclosed herein will be described below with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. Furthermore, the drawings may contain parts with different dimensional relationships and ratios.

In addition, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

Furthermore, each embodiment can be combined as appropriate to the extent that the processing content is not contradictory. Furthermore, in each of the following embodiments, the same parts are given the same symbols, and duplicate explanations will be omitted.

[Embodiment]
<Printer configuration>
First, an overview of a printer, which is an example of a liquid ejection device according to an embodiment, will be described with reference to Figures 1 and 2. Figure 1 is a front view that schematically shows the front surface of the printer according to an embodiment. Figure 2 is a plan view that schematically shows the plane of the printer according to an embodiment. The printer according to an embodiment is, for example, a color inkjet printer.

As shown in Figure 1, the printer 1 includes a paper feed roller 2, a guide roller 3, an applicator 4, a head case 5, multiple transport rollers 6, multiple frames 7, multiple liquid ejection heads 8, a transport roller 9, a dryer 10, a transport roller 11, a sensor unit 12, and a recovery roller 13. The transport roller 6 is an example of a transport unit.

The printer 1 further includes a control unit 14. The control unit 14 controls each part of the printer 1. The control unit 14 controls the operation of, for example, the paper feed roller 2, the guide roller 3, the coater 4, the head case 5, the plurality of conveying rollers 6, the plurality of frames 7, the plurality of liquid ejection heads 8, the conveying roller 9, the dryer 10, the conveying roller 11, the sensor unit 12, and the recovery roller 13.

The printer 1 records images and characters on the printing paper P by causing droplets to land on the printing paper P. The printing paper P is an example of a recording medium. Before use, the printing paper P is wound around the paper feed roller 2. The printer 1 transports the printing paper P from the paper feed roller 2 through the guide roller 3 and the coater 4 into the head case 5.

The applicator 4 applies the coating agent evenly to the printing paper P. This allows the printing paper P to be surface treated, thereby improving the printing quality of the printer 1.

The head case 5 houses multiple transport rollers 6, multiple frames 7, and multiple liquid ejection heads 8. Inside the head case 5, a space is formed that is isolated from the outside, except for some areas that are connected to the outside, such as the area where the printing paper P enters and exits.

At least one of the control factors such as temperature, humidity, and air pressure of the internal space of the head case 5 is controlled by the control unit 14 as necessary. The transport roller 6 transports the printing paper P inside the head case 5 to the vicinity of the liquid ejection head 8.

The frame 7 is a rectangular flat plate and is positioned close to and above the printing paper P being transported by the transport rollers 6. As shown in Figure 2, the frame 7 is positioned so that its longitudinal direction is perpendicular to the transport direction of the printing paper P. Inside the head case 5, multiple (for example, four) frames 7 are positioned at predetermined intervals along the transport direction of the printing paper P.

The liquid ejection head 8 is supplied with liquid, such as ink, from a liquid tank (not shown). The liquid ejection head 8 ejects the liquid supplied from the liquid tank.

The control unit 14 controls the liquid ejection head 8 based on data such as images and characters, causing it to eject liquid toward the printing paper P. The distance between the liquid ejection head 8 and the printing paper P is, for example, approximately 0.5 mm to 20 mm.

The liquid ejection head 8 is fixed to the frame 7. The liquid ejection head 8 is positioned so that its longitudinal direction is perpendicular to the transport direction of the printing paper P.

In other words, the printer 1 according to this embodiment is a so-called line printer in which the liquid ejection head 8 is fixed inside the printer 1. Note that the printer 1 according to this embodiment is not limited to a line printer, and may also be a so-called serial printer.

A serial printer is a printer that alternates between recording by moving the liquid ejection head 8 back and forth in a direction that intersects the transport direction of the printing paper P, for example, in a direction that is approximately perpendicular, and transporting the printing paper P.

As shown in Figure 2, multiple (e.g., five) liquid ejection heads 8 are fixed to one frame 7. Figure 2 shows an example in which three liquid ejection heads 8 are positioned in front and two in the rear in the transport direction of the printing paper P, and the liquid ejection heads 8 are positioned so that the centers of each liquid ejection head 8 do not overlap in the transport direction of the printing paper P.

A head group 8A is made up of multiple liquid ejection heads 8 positioned on one frame 7. The four head groups 8A are positioned along the transport direction of the printing paper P. Four colors of ink are supplied to the liquid ejection heads 8 belonging to the same head group 8A. This allows the printer 1 to print with four colors of ink using the four head groups 8A.

The colors of ink ejected from each liquid ejection head 8 are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 14 controls each liquid ejection head 8 to eject multiple colors of ink onto the printing paper P, thereby printing a color image on the printing paper P.

In addition, to treat the surface of the printing paper P, a coating agent may be ejected onto the printing paper P from the liquid ejection head 8.

In addition, the number of liquid ejection heads 8 included in one head group 8A and the number of head groups 8A mounted on the printer 1 can be changed as appropriate depending on the object to be printed and the printing conditions. For example, if printing is to be performed within the range that can be printed with one liquid ejection head 8, the number of liquid ejection heads 8 mounted on the printer 1 may be one.

The printing paper P that has been printed inside the head case 5 is transported outside the head case 5 by the transport rollers 9 and passes through the inside of the dryer 10. The dryer 10 dries the printing paper P that has been printed. The printing paper P that has been dried in the dryer 10 is transported by the transport rollers 11 and collected by the collection rollers 13.

In the printer 1, by drying the printing paper P in the dryer 10, it is possible to prevent the printing paper P that is wound up in a stack on the recovery roller 13 from sticking together or the undried liquid from rubbing against each other.

The sensor unit 12 is composed of a position sensor, a speed sensor, a temperature sensor, etc. Based on information from the sensor unit 12, the control unit 14 can determine the status of each part of the printer 1 and control each part of the printer 1.

The printer 1 described so far has been shown to use printing paper P as the printing target (i.e., recording medium), but the printing target in printer 1 is not limited to printing paper P, and rolls of cloth, etc. may also be used as the printing target.

In addition, instead of directly transporting the printing paper P, the printer 1 may transport the paper by placing it on a conveyor belt. By using a conveyor belt, the printer 1 can print on sheets of paper, cut pieces of cloth, wood, tiles, etc.

The printer 1 may also print wiring patterns for electronic devices by ejecting a liquid containing conductive particles from the liquid ejection head 8. The printer 1 may also produce chemicals by ejecting a predetermined amount of liquid chemicals or liquid containing chemicals from the liquid ejection head 8 toward a reaction vessel or the like.

The printer 1 may also be equipped with a cleaning unit that cleans the liquid ejection head 8. The cleaning unit cleans the liquid ejection head 8, for example, by wiping or capping.

The wiping process is a process of removing liquid adhering to the liquid ejection head 8, for example, by wiping the surface from which the liquid is ejected with a flexible wiper.

The capping process is performed, for example, as follows: First, a cap is placed over the surface of the area where the liquid is to be ejected (this is called capping). This creates a substantially sealed space between the surface of the area where the liquid is to be ejected and the cap. Next, the liquid is repeatedly ejected into this sealed space. This makes it possible to remove liquid with a higher viscosity than normal or foreign matter that has clogged the nozzle 21A (see Figure 3).

<Configuration of Liquid Ejection Head>
Next, the configuration of the liquid ejection head 8 according to the embodiment will be described with reference to Fig. 3. Fig. 3 is a perspective view showing an example of a liquid ejection head according to the embodiment.

For ease of understanding, Figure 3 illustrates a three-dimensional Cartesian coordinate system including a Z-axis with the positive direction being the vertically upward direction. This Cartesian coordinate system may also be shown in other drawings used in the following explanation. For convenience, in the following explanation, the direction in which nozzle 21A (see Figure 3) is located in the liquid ejection head 8, i.e., the negative Z-axis direction, may be referred to as "down" or "downward," and the positive Z-axis direction may be referred to as "up" or "upward." In addition, in Figures 3 to 6, various components may be omitted or simplified.

As shown in Figure 3, the liquid ejection head 8 comprises a first flow path member 21, a second flow path member 22, a pressure applying section 23, a first flow path 27, a second flow path 28, a head cover 29, a heat sink 30, and conductive sections 41 and 42.

The first flow path member 21 is located on the bottom side of the liquid ejection head 8, facing the printing paper P (see Figure 1). The first flow path member 21 has a nozzle 21A. The nozzle 21A opens to the bottom surface of the liquid ejection head 8 and ejects liquid supplied inside the first flow path member 21 to the outside.

The first flow path member 21 is electrically conductive. The material of the first flow path member 21 may be, for example, stainless steel.

The second flow path member 22 is located above the first flow path member 21. The second flow path member 22 supplies liquid to the first flow path member 21. The second flow path member 22 has a flow path 22A that connects to the nozzle 21A. Liquid is supplied from the first flow path 27 to the inside of the flow path 22A.

The second flow path member 22 may be made of a material such as a modified polyphenylene ether (PPE) resin, such as Zylon (trade name), or an epoxy resin, such as Epocluster (registered trademark). The second flow path member 22 may also contain a carbon material, such as carbon black.

The pressurizing unit 23 applies pressure to the first flow path member 21. The pressurizing unit 23 controls the ejection of liquid from the first flow path member 21 in response to a control signal output from the control unit 14 (see Figure 1). The pressurizing unit 23 has a piezoelectric element that is displaced when energized, and a pressure chamber whose internal pressure changes in response to the displacement of the piezoelectric element. The pressurizing unit 23 changes the internal pressure of the pressure chamber, thereby changing the pressure applied to the first flow path member 21 and controlling the ejection of liquid from the nozzle 21A.

The first flow path 27 supplies liquid to the flow path 22A of the second flow path member 22. The second flow path 28 recovers liquid from the flow path 22A of the second flow path member 22. When ink is initially introduced into the liquid ejection head 8, air and preservative liquid present inside the flow path 22A can be removed through the second flow path 28 to facilitate the introduction of ink into the liquid ejection head 8. When printing, the second flow path 28 may be closed, or the ink in the flow path 22A may be recovered. The liquid recovered from the second flow path 28 is supplied to the first flow path 27, for example, through a filter (not shown).

The head cover 29 is plate-shaped and is positioned to cover the space located on the opposite side of the first flow path member 21, across the second flow path member 22.

The head cover 29 can be made of a conductive metal material, such as aluminum. The head cover 29 may also be made of a conductive or insulating resin material, for example. This allows the liquid ejection head 8 to properly dissipate heat through the head cover 29. The head cover 29 may also have a higher thermal conductivity than the second flow path member 22. This makes it less likely that heat will be conducted from the head cover 29 to the second flow path member 22. This can reduce the possibility of changes in the properties of the liquid flowing inside the second flow path member 22, resulting in problems with ejection performance.

The head cover 29 may be in contact with the second flow path member 22 or may be spaced apart from the second flow path member 22. Positioning the head cover 29 spaced apart from the second flow path member 22 reduces the likelihood of heat conduction from the head cover 29 to the second flow path member 22 and promotes heat conduction to the heat sinks 31, 32. This reduces the possibility of changes in the properties of the liquid flowing inside the second flow path member 22, resulting in problems with ejection performance.

The heat sinks 30 are plate-shaped members positioned along the YZ plane. The heat sinks 30 are positioned facing each other in the X-axis direction, sandwiching the head cover 29 between them. Note that the heat sinks 30 may be positioned only at the end on the positive or negative X-axis side.

The heat sink 30 may be made of, for example, the same material as the head cover 29. The heat sink 30 may also be made of, for example, a material with a higher thermal conductivity than the head cover 29.

The conductive portions 41 and 42 are located at the ends of the length (Y-axis direction). The conductive portion 41 is located at the end on the negative side of the Y-axis, and the conductive portion 42 is located at the end on the positive side of the Y-axis. The conductive portions 41 and 42 have a positioning mechanism that determines the position of the nozzle 21A. Furthermore, the conductive portions 41 and 42 are made of a conductive material that is more conductive than the second flow path member 22, and are electrically connected to the first flow path member 21. This allows for stable grounding.

<Configuration of Conductive Part>
Next, the configuration of the conductive portions 41, 42 of the liquid ejection head 8 according to this embodiment will be further described with reference to Figures 3 to 6. Figure 4A is an enlarged perspective view of region IV shown in Figure 3. Figure 4B is a perspective view of region IV shown in Figure 3, viewed from a different direction. Figure 5A is an enlarged perspective view of region V shown in Figure 3. Figure 5B is a perspective view of region V shown in Figure 3, viewed from a different direction. Figure 6 is a cross-sectional view showing an example of a liquid ejection head according to this embodiment.

As shown in Figures 3 to 4B, the conductive portion 41 serving as the first conductive portion has a plate-shaped member 43 and a grounding member 44. The conductive portion 41 can be made of the same metal material as the first flow path member 21. This makes galvanic corrosion, also known as bimetallic corrosion, less likely to occur, improving the durability of the liquid ejection head 8.

The plate-shaped member 43 is located on the positive Z-axis side of the second flow path member 22. The plate-shaped member 43 is fixed to the second flow path member 22 using first fixing members 51 and 52.

The plate-shaped member 43 has a protrusion 431 that protrudes in the longitudinal direction (negative Y-axis direction), and the plate-shaped member 43 has a generally L-shape when viewed in a plan view in the Z-axis direction. When the liquid ejection head 8 is mounted on a liquid ejection device, the plate-shaped member 43 functions as a positioning mechanism at one end in the longitudinal direction (negative Y-axis direction).

The plate-shaped member 43 can be fixed to the grounding member 44 of the conductive portion 41 using the first fixing members 51, 52. This allows the plate-shaped member 43 to be fixed to the grounding member 44, which has higher rigidity than the second flow path member 22, improving the positioning accuracy of the plate-shaped member 43.

The grounding member 44 is located on the negative Z-axis side of the second flow path member 22. The grounding member 44 is fixed to the second flow path member 22 using first fixing members 51 and 52. The grounding member 44 is also fixed to the first flow path member 21 and the second flow path member 22 using second fixing members 61 and 62. The first fixing members 51 and 52 and the second fixing members 61 and 62 may be, for example, metal screw members.

As shown in Figures 3, 5A, and 5B, the conductive portion 42 serving as the second conductive portion may include a plate-shaped member 45 and a grounding member 46. The plate-shaped member 45 is located on the positive Z-axis side of the second flow path member 22. The plate-shaped member 45 is fixed to the second flow path member 22 using first fixing members 53 and 54.

The plate-like member 45 protrudes in the lengthwise direction (positive Y-axis direction) and has a notch 451 in the center of the widthwise direction (positive Y-axis direction). When the liquid ejection head 8 is mounted on a liquid ejection device, the plate-like member 45 functions as a positioning mechanism at one end in the lengthwise direction (positive Y-axis direction). For example, by positioning the liquid ejection head 8 so that a columnar or rod-shaped guide member (not shown) extending in the heightwise direction (Z-axis direction) contacts the notch 451, a liquid ejection device having the nozzle 21A in a predetermined position can be obtained.

The plate-shaped member 45 can be fixed to the grounding member 46 of the conductive portion 42 using the first fixing members 53, 54. This allows the plate-shaped member 45 to be fixed to the grounding member 46, which has higher rigidity than the second flow path member 22, improving the positioning accuracy of the plate-shaped member 45.

The grounding member 46 is located on the negative Z-axis side of the second flow path member 22. The grounding member 46 is fixed to the second flow path member 22 using first fixing members 53, 54. The grounding member 46 is also fixed to the first flow path member 21 and the second flow path member 22 using second fixing members 63, 64. The first fixing members 53, 54 and the second fixing members 63, 64 may be, for example, metal screw members.

As shown in FIG. 6, the grounding member 44 may have a first portion 441 and a second portion 442. The grounding member 46 may have a first portion 461 and a second portion 462. The first portions 441, 461 may be contact surfaces that come into contact with the mounting surfaces 1f, 1g, respectively, of a printer 1, which is an example of a liquid ejection device, when the liquid ejection head 8 is mounted on the mounting surfaces 1f, 1g. The liquid ejection head 8 mounted on the mounting surfaces 1f, 1g can be stably grounded by properly grounding the first portions 441, 461. In this way, by having conductive portions 41, 42 that are electrically connected to the first flow path member 21 and have higher conductivity than the second flow path member 22, stable grounding is possible, for example, even when electrical noise occurs.

The second portions 442, 462 are contact surfaces that come into contact with the first flow path member 21. The second fixing members 61-64 that fix the first flow path member 21 and the second flow path member 22 penetrate these second portions 442, 462. The second fixing members 61, 62 penetrate the second portion 442. The second fixing members 63, 64 penetrate the second portion 462. In this way, by having the second fixing members 61-64 penetrate the second portions 442, 462 of the grounding members 44, 46, stable contact can be achieved between the grounding members 44, 46 and the first flow path member 21, and the grounding resistance of the liquid ejection head 8 can be reduced.

In addition, since the second fixing members 61, 62 penetrate the second portion 442 of the grounding member 44 and the second fixing members 63, 64 penetrate the second portion 462 of the grounding member 46, deformation of the grounding members 44, 46 and tilting of the grounding members 44, 46 due to the moment force generated by fastening the second fixing members 61 to 64 are less likely to occur compared to when the second fixing members 61, 62 penetrate a portion other than the second portions 442, 462.

Also, as shown in Figures 3 to 5B, the grounding member 44 of the conductive portion 41 and the first flow path member 21 may be in contact across the width direction (X-axis direction).Also, the grounding member 46 of the conductive portion 42 and the first flow path member 21 may be in contact across the width direction (X-axis direction).This increases the contact area between the conductive portions 41, 42 and the first flow path member 21, allowing the first flow path member 21 to be stably grounded.

The conductive portions 41, 42 may also be in contact with the second flow path member 22 across the width direction (X-axis direction). This improves the positional stability of the conductive portions 41, 42 relative to the second flow path member 22.

As shown in FIG. 6, the area of the first portion 441 of the grounding member 44 may be larger than the area of the second portion 442. Similarly, the area of the first portion 461 of the grounding member 46 may be larger than the area of the second portion 462. Alternatively, the area of the second portion 442 may be larger than the area of the first portion 441, and the area of the second portion 462 may be larger than the area of the first portion 461. If the area of the second portion 442 is larger than the area of the first portion 441, for example, the contact area between the first flow path member 21 and the grounding member 44 can be increased. Also, if the area of the second portion 462 is larger than the area of the first portion 461, for example, the contact area between the first flow path member 21 and the grounding member 46 can be increased. This allows for stable grounding.

6, the grounding member 44 may have a step between the first portion 441 and the second portion 442, or the first portion 441 and the second portion 442 may be flush. Similarly, the grounding member 46 may have a step between the first portion 461 and the second portion 462, or the first portion 461 and the second portion 462 may be flush.

Figure 7 is a perspective view showing an example of a second flow path member provided in a liquid ejection head according to an embodiment. Figure 8 is a perspective view showing an example of a state in which a grounding member is installed on the second flow path member shown in Figure 7. Figure 9 is a cross-sectional view showing an example of a liquid ejection head according to an embodiment.

As shown in FIG. 7, the second flow path member 22 may have a bottom surface 221 and a peripheral wall 222. The bottom surface 221 is recessed toward the positive Z-axis direction from the end face of the second flow path member 22 on the negative Z-axis direction side, which is positioned opposite the first flow path member 21. The peripheral wall 222 is positioned to surround the bottom surface 221. The grounding member 44 is attached so as to be embedded in a recess in the second flow path member 22, which has the bottom surface 221 and the peripheral wall 222. In this way, by embedding the grounding member 44 in the recess in the second flow path member 22, the rigidity of the second flow path member 22 is improved and the positional stability of the grounding member 44 in the liquid ejection head 8 is improved.

The second flow path member 22 may also have a protruding pin 223. The protruding pin 223 protrudes from the bottom surface 221 toward the negative Z-axis direction. As shown in FIG. 8, the protruding pin 223 is inserted into a through hole 443 that penetrates the grounding member 44 in the thickness direction (Z-axis direction). As shown in FIG. 9, the tip of the protruding pin 223 is located inside the first flow path member 21. By having such a protruding pin 223, the positional stability of the first flow path member 21 and the second flow path member 22 is improved. Furthermore, since the material cost of the grounding member 44 can be reduced compared to when a protruding pin protruding from the grounding member 44 is included, the manufacturing cost of the liquid ejection head 8 can be reduced.

Note that Figures 7 to 9 describe the shape of the second flow path member 22 located on the grounding member 44 side, but the second flow path member 22 located on the grounding member 46 side can also have a similar shape.

Returning to Figure 6, the liquid ejection head 8 may have a connection portion 50. The connection portion 50 connects the conductive portions 41, 42 located at both ends in the longitudinal direction (Y-axis direction). The connection portion 50 is conductive. The connection portion 50 may be made of the same metal material as the first flow path member 21. The connection portion 50 may be part of the first flow path member 21.

The connection part 50 may be located between the nozzle 21A and the conductive parts 41, 42. The connection part 50 may be, for example, a lid-like member that closes the liquid flow path located inside the first flow path member 21. The connection part 50 may also have, for example, a housing part that houses the pressure part 23 (see Figure 3) inside. The connection part 50 may be integral with the first flow path member 21 or may be separate from the first flow path member 21. By having the connection part 50 in the liquid ejection head 8, the first flow path member 21 can be quickly connected to the liquid ejection device, thereby achieving stable grounding.

Figure 10 is a cross-sectional view showing another example of a liquid ejection head according to an embodiment. As shown in Figure 10, the liquid ejection head 8 may have a conductive member 40. The conductive member 40 can be made of the same metal material as the first flow path member 21.

Figure 11 is a perspective view showing an example of a conductive member according to an embodiment. As shown in Figures 10 and 11, the conductive member 40 may have grounding portions 44A, 46A located at both ends in the longitudinal direction (Y-axis direction), and a connection portion 50A located between the grounding portions 44A, 46A.

The grounding portions 44A, 46A have first portions 441, 461, respectively, that are placed on the mounting surfaces 1f, 1g of the printer 1. The grounding portions 44A, 46A correspond to the grounding members 44, 46 shown in FIG. 6. The connection portion 50A corresponds to the connection portion 50 shown in FIG. 6. The conductive member 40 integrally includes the grounding portions 44A, 46A and the connection portion 50A. With a liquid ejection head 8 equipped with such a conductive member 40, the grounding portions 44A, 46A are less likely to shift position, even if the liquid ejection head 8 is subjected to an external force. This allows for stable grounding of the liquid ejection head 8.

<Other embodiments>
In the above-described embodiment, the grounding members 44, 46 are fixed at four points using the first fixing member and the second fixing member, but the grounding members 44, 46 may be fixed at two or more points. For example, if the grounding members 44, 46 are fixed at two points, one point may function to position the grounding members 44, 46, and the other point may function to prevent rotation of the grounding members 44, 46. This makes it less likely that the grounding members 44, 46 will become misaligned, even if the liquid ejection head 8 is subjected to an external force.

The above-described embodiments also describe a mode in which ink is supplied from the outside to a reservoir formed by the second flow path member 22, and a mode in which ink is supplied from the outside to the reservoir and recovered from the reservoir to the outside during printing. In the latter mode, ink may be supplied from the reservoir to the first flow path member 21 and recovered from the first flow path member 21 to the reservoir. Furthermore, ink may be supplied to and recovered from the flow path within the first flow path member 21 facing the nozzle 21A, thereby preventing ink from accumulating within and around the nozzle 21A. In such a mode, ink is supplied from the outside to the liquid ejection head 8 as a whole, some of the ink is ejected, and the ink that was not ejected is recovered to the outside. The ink recovered to the outside may be supplied again to the liquid ejection head 8. In other words, the ink may be circulated. The supply and recovery of ink to the liquid ejection head 8, or the circulation of ink, may be controlled by the control unit 14.

As described above, the liquid ejection head 8 according to the embodiment comprises a first flow path member 21, a second flow path member 22, and conductive portions 41 and 42. The first flow path member 21 is conductive and has a nozzle 21A that ejects liquid. The second flow path member 22 supplies liquid to the first flow path member 21. The conductive portions 41 and 42 have a positioning mechanism that determines the position of the nozzle 21A. The conductive portions 41 and 42 are electrically conductive with the first flow path member 21 and have higher conductivity than the second flow path member 22. As a result, the liquid ejection head 8 according to the embodiment can achieve stable grounding.

Further advantages and modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

REFERENCE SIGNS LIST 1 Printer 8 Liquid ejection head 14 Control unit 21 First flow path member 21A Nozzle 22 Second flow path member 23 Pressurizing unit 29 Head cover 30 Heat sink 40 Conductive members 41, 42 Conductive portions 43, 45 Plate-shaped members 44, 46 Grounding member

Claims (10)

a conductive first flow path member having a nozzle for discharging a liquid;
a second flow path member that supplies the liquid to the first flow path member;
a conductive portion having a positioning mechanism for determining the position of the nozzle, being electrically connected to the first flow path member and having a higher conductivity than the second flow path member ,
a fixing member that fixes the first flow path member and the second flow path member,
The liquid ejection head, wherein the fixing member penetrates the conductive portion . a conductive first flow path member having a nozzle for discharging a liquid;
a second flow path member that supplies the liquid to the first flow path member;
a conductive portion having a positioning mechanism for determining the position of the nozzle, being electrically connected to the first flow path member and having a higher conductivity than the second flow path member ,
a fixing member that fixes the first flow path member and the second flow path member,
The liquid ejection head, wherein the immobilizing member penetrates the contact surface between the conductive portion and the first flow path member . a conductive first flow path member having a nozzle for discharging a liquid;
a second flow path member that supplies the liquid to the first flow path member;
a conductive portion having a positioning mechanism for determining the position of the nozzle, being electrically connected to the first flow path member and having a higher conductivity than the second flow path member ,
the positioning mechanism has a plate-like member,
The liquid ejection head , wherein the plate-like member is fixed to the conductive portion using a fixing member . a conductive first flow path member having a nozzle for discharging a liquid;
a second flow path member that supplies the liquid to the first flow path member;
a conductive portion having a positioning mechanism for determining the position of the nozzle, being electrically connected to the first flow path member and having a higher conductivity than the second flow path member ,
the second flow path member has a recess,
The conductive portion is embedded in the recess . The liquid ejection head according to claim 1 , wherein the conductive portion and the first flow path member are in contact with each other across the width direction. The liquid ejection head according to claim 1 , wherein the conductive portion and the second flow path member are in contact with each other across the width direction. 5. The liquid ejection head according to claim 1, wherein the conductive portion is made of the same metal material as the first flow path member. 5. The liquid ejection head according to claim 1, wherein the conductive portion is fixed at two or more points. the conductive portion has a first conductive portion and a second conductive portion located at both ends in a length direction,
5. The liquid ejection head according to claim 1, further comprising a connection portion that connects the first conductive portion and the second conductive portion. A liquid ejection head according to any one of claims 1 to 4 ;
a mounting surface on which the liquid ejection head is mounted,
The conductive portion of the liquid ejection head is located on the mounting surface.