JP6648288B2 - Liquid ejection head and recording device - Google Patents

Description

  The present disclosure relates to a liquid ejection head and a recording device.

  2. Description of the Related Art Conventionally, as a print head, for example, a liquid discharge head that performs various types of printing by discharging a liquid onto a recording medium is known. The liquid ejection head includes, for example, a flow path member and a plurality of pressurizing units. The flow path member of Patent Document 1 includes, for example, a plurality of discharge holes, a plurality of pressure chambers respectively connected to the plurality of discharge holes, a plurality of first individual flow paths respectively connected to the plurality of pressure chambers, , A plurality of second individual flow paths respectively connected to the pressure chambers, a plurality of first individual flow paths, and a common flow path commonly connected to the plurality of second individual flow paths. The plurality of pressurizing units press each of the plurality of pressurizing chambers.

JP 2008-200902 A

  A liquid ejection head according to an aspect of the present disclosure includes a flow path member and a plurality of pressure units. The flow path member includes a plurality of discharge holes, a plurality of pressurized chambers respectively connected to the plurality of discharge holes, a plurality of first flow paths respectively connected to the plurality of pressurized chambers, and a plurality of the pressurized chambers. A plurality of second flow paths respectively connected to the pressure chambers, a plurality of third flow paths respectively connected to the plurality of pressurization chambers, a plurality of the first flow paths, and a plurality of the second flow paths. A fourth flow path is connected in common, and a fifth flow path is connected in common to the plurality of third flow paths. The plurality of pressurizing units pressurize liquids in the plurality of pressurized chambers, respectively. The flow path member further includes a partition section that partitions the inside of the fourth flow path into a first section on one side and a second section on the other side in a direction intersecting the flow direction of the fourth flow path. Have. The plurality of first flow paths are connected to the first section. The plurality of second flow paths are connected to the second section.

  A recording apparatus according to an aspect of the present disclosure includes the above-described liquid discharge head, a transport unit that transports a recording medium to the liquid discharge head, and a control unit that controls the liquid discharge head.

FIG. 2A is a side view schematically illustrating a recording apparatus including the liquid ejection head according to the first embodiment, and FIG. 2B is a plan view schematically illustrating the recording apparatus including the liquid ejection head according to the first embodiment. FIG. FIG. 2 is an exploded perspective view of the liquid ejection head according to the first embodiment. FIG. 3A is a perspective view of the liquid discharge head of FIG. 2, and FIG. 3B is a cross-sectional view of the liquid discharge head of FIG. (A) is an exploded perspective view of the head main body, and (b) is a perspective view seen from the lower surface of the second flow path member. (A) is a plan view of the head main body seen through a part of the second flow path member, and (b) is a plan view of the head main body seen through the second flow path member. It is a top view which expands and shows a part of FIG. (A) is a perspective view of the discharge unit, (b) is a plan view of the discharge unit, and (c) is a plan view showing electrodes on the discharge unit. 7A is a sectional view taken along line VIIIa-VIIIa in FIG. 7B, and FIG. 7B is a sectional view taken along line VIIIb-VIIIb in FIG. 7B. FIG. 3 is a conceptual diagram illustrating a flow of a fluid inside a liquid ejection unit. 10A is a plan view showing the installation range of the partition, and FIG. 10B is a cross-sectional view taken along line Xb-Xb in FIG. (A) is a perspective view showing a partition part according to a modification, (b) is a cross-sectional view showing a partition part according to another modification, and (c) is a cross-sectional view showing a partition part according to still another modification. is there.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings used in the following description are schematic, and the dimensional ratios and the like in the drawings do not always match actual ones. Even in a plurality of drawings showing the same member, dimensional ratios and the like may not match each other in order to exaggerate shapes and the like.

<First embodiment>
(Overall configuration of printer)
A color inkjet printer 1 (hereinafter, referred to as a printer 1) including a liquid ejection head 2 according to the first embodiment will be described with reference to FIG.

  The printer 1 moves the recording medium P relatively to the liquid ejection head 2 by conveying the recording medium P from the conveyance roller 74a to the conveyance roller 74b. The control unit 76 controls the liquid ejection head 2 based on image and character data to eject liquid toward the recording medium P, land droplets on the recording medium P, and print on the recording medium P. Perform

  In the present embodiment, the liquid ejection head 2 is fixed to the printer 1, and the printer 1 is a so-called line printer. Another embodiment of the recording apparatus is a so-called serial printer.

  A flat head mounting frame 70 is fixed to the printer 1 so as to be substantially parallel to the recording medium P. The head mounting frame 70 is provided with 20 holes (not shown), and 20 liquid ejection heads 2 are mounted in each hole. The five liquid ejection heads 2 constitute one head group 72, and the printer 1 has four head groups 72.

  The liquid ejection head 2 has an elongated shape as shown in FIG. In one head group 72, the three liquid discharge heads 2 are arranged in a direction intersecting the transport direction of the recording medium P, and the other two liquid discharge heads 2 are displaced along the transport direction. , One each between the three liquid ejection heads 2. The adjacent liquid ejection heads 2 are arranged so that the printable range of each liquid ejection head 2 is connected in the width direction of the recording medium P or the ends thereof overlap. Printing without gaps is possible.

  The four head groups 72 are arranged along the transport direction of the recording medium P. Each liquid ejection head 2 is supplied with ink from a liquid tank (not shown). The same color ink is supplied to the liquid ejection heads 2 belonging to one head group 72, and the four head groups print four color inks. The colors of the ink ejected from each head group 72 are, for example, magenta (M), yellow (Y), cyan (C), and black (K).

  Note that the number of the liquid discharge heads 2 mounted on the printer 1 may be one as long as it is a single color and a printable range can be printed by one liquid discharge head 2. The number of the liquid ejection heads 2 included in the head group 72 or the number of the head groups 72 can be appropriately changed depending on a printing target and printing conditions. For example, the number of head groups 72 may be increased to perform multi-color printing. Further, by arranging a plurality of head groups 72 for printing in the same color and alternately printing in the transport direction, the printing speed, that is, the transport speed can be increased. Alternatively, a plurality of head groups 72 for printing in the same color may be prepared and arranged so as to be shifted in a direction intersecting the transport direction to increase the resolution of the recording medium P in the width direction.

  Further, in addition to printing colored ink, a liquid such as a coating agent may be printed in order to perform a surface treatment on the recording medium P.

  The printer 1 performs printing on the recording medium P. The recording medium P is wound around the transport rollers 74a, passes between the two transport rollers 74c, and then passes below the liquid ejection head 2 mounted on the head mounting frame 70. Thereafter, the paper passes between the two transport rollers 74d and is finally collected by the transport rollers 74b.

  The recording medium P may be a cloth or the like in addition to the printing paper. In addition, the printer 1 is configured to convey a conveyance belt instead of the recording medium P. The recording medium may be a sheet, a cut cloth, wood, Alternatively, it may be a tile or the like. Further, a wiring pattern of an electronic device may be printed by discharging a liquid containing conductive particles from the liquid discharging head 2. Furthermore, a chemical may be produced by discharging a predetermined amount of liquid chemical or a liquid containing the chemical from the liquid discharge head 2 toward a reaction container or the like to cause a reaction.

  Further, a position sensor, a speed sensor, a temperature sensor, and the like may be attached to the printer 1, and the control unit 76 may control each unit of the printer 1 according to the state of each unit of the printer 1 that can be obtained from information from each sensor. In particular, if the discharge characteristics (discharge amount, discharge speed, and the like) of the liquid discharged from the liquid discharge head 2 are externally affected, the temperature of the liquid discharge head 2, the temperature of the liquid in the liquid tank, and the temperature of the liquid tank A drive signal for causing the liquid ejection head 2 to eject the liquid may be changed according to the pressure applied to the liquid ejection head 2 by the liquid.

(Overall configuration of liquid ejection head)
Next, the liquid ejection head 2 according to the first embodiment will be described with reference to FIGS. In FIGS. 5 and 6, for easy understanding of the drawings, the flow paths and the like that should be drawn by broken lines below other members are drawn by solid lines. 5A, a part of the second flow path member 6 is shown transparently, and in FIG. 5B, the entire second flow path member 6 is transparently shown. In FIG. 9, the flow of the conventional liquid is indicated by a broken line, the flow of the liquid in the ejection unit 15 is indicated by a solid line, and the flow of the liquid supplied from the second individual flow path 14 is indicated by a long broken line.

  In the drawings, a first direction D1, a second direction D2, a third direction D3, a fourth direction D4, a fifth direction D5, and a sixth direction D6 are illustrated. The first direction D1 is one side of the direction in which the first common channel 20 and the second common channel 24 extend, and the fourth direction D4 is the direction in which the first common channel 20 and the second common channel 24 extend. On the other side. The second direction D2 is one side of the direction in which the first integrated channel 22 and the second integrated channel 26 extend, and the fifth direction D5 is the direction in which the first integrated channel 22 and the second integrated channel 26 extend. On the other side. The third direction D3 is one side in a direction orthogonal to the direction in which the first integrated flow path 22 and the second integrated flow path 26 extend, and the sixth direction D6 is the first integrated flow path 22 and the second integrated flow path. The other side in the direction orthogonal to the direction in which 26 extends.

  In the liquid discharge head 2, the first individual flow path 12 as the first flow path, the second individual flow path 14 as the second flow path, the third individual flow path 16 as the third flow path, and the first individual flow path as the fourth flow path. The description will be made using the common channel 20 and the second common channel 24 as the fifth channel.

  As shown in FIGS. 2 and 3, the liquid ejection head 2 includes a head main body 2 a, a housing 50, a heat sink 52, a wiring board 54, a pressing member 56, an elastic member 58, a signal transmission unit 60, , And a driver IC 62. Note that the liquid ejection head 2 only needs to include the head main body 2a, and does not necessarily include the housing 50, the heat radiating plate 52, the wiring board 54, the pressing member 56, the elastic member 58, the signal transmission unit 60, and the driver IC 62. It is not necessary.

  In the liquid ejection head 2, the signal transmission unit 60 is drawn out of the head main body 2a, and the signal transmission unit 60 is electrically connected to the wiring board 54. The signal transmission section 60 is provided with a driver IC 62 for controlling the driving of the liquid ejection head 2. The driver IC 62 is pressed against the heat radiating plate 52 by the pressing member 56 via the elastic member 58. The illustration of the support member that supports the wiring board 54 is omitted.

  The heat radiating plate 52 can be formed of a metal or an alloy, and is provided to radiate heat of the driver IC 62 to the outside. The radiator plate 52 is joined to the housing 50 with a screw or an adhesive.

  The housing 50 is mounted on the upper surface of the head main body 2a, and the housing 50 and the heat radiating plate 52 cover each member constituting the liquid ejection head 2. The housing 50 includes a first opening 50a, a second opening 50b, a third opening 50c, and a heat insulating part 50d. The first openings 50a are provided so as to face the third direction D3 and the sixth direction D6, respectively. By disposing the heat sink 52 in the first opening 50a, the first opening 50a is sealed. The second opening 50b is opened downward, and the wiring board 54 and the pressing member 56 are arranged inside the housing 50 via the second opening 50b. The third opening 50c is open upward, and accommodates a connector (not shown) provided on the wiring board 54.

  The heat insulating portion 50d is provided so as to extend from the second direction D2 to the fifth direction D5, and is disposed between the heat sink 52 and the head main body 2a. Thereby, the possibility that the heat radiated to the heat radiating plate 52 is transmitted to the head main body 2a can be reduced. The housing 50 can be formed of a metal, an alloy, or a resin.

  As shown in FIG. 4A, the head main body 2a has a long flat plate shape from the second direction D2 to the fifth direction D5, and the first flow path member 4, the second flow path member 6, , A piezoelectric actuator substrate 40. The head main body 2 a is provided with a piezoelectric actuator substrate 40 and a second flow path member 6 on the upper surface of the first flow path member 4. The piezoelectric actuator substrate 40 is placed in a region indicated by a broken line in FIG. The piezoelectric actuator substrate 40 is provided for pressurizing a plurality of pressurizing chambers 10 (see FIG. 8) provided in the first flow path member 4, and has a plurality of displacement elements 48 (see FIG. 8). ing.

(Overall configuration of flow path member)
The first flow path member 4 has a plurality of flow paths formed therein, and guides the liquid supplied from the second flow path member 6 to the discharge holes 8 provided on the lower surface (see FIG. 8). . The upper surface of the first flow path member 4 is a pressurizing chamber surface 4-1, and openings 20a, 24a, 28c, and 28d are formed in the pressurizing chamber surface 4-1. A plurality of openings 20a are provided, and are arranged along the second direction D2 to the fifth direction D5. The opening 20a is arranged at an end of the pressurizing chamber surface 4-1 in the third direction D3. The plurality of openings 24a are provided, and are arranged along the second direction D2 to the fifth direction D5. The opening 24a is arranged at an end of the pressurizing chamber surface 4-1 in the sixth direction D6. The opening 28c is provided outside the opening 20a in the second direction D2 and outside in the fifth direction D5. The opening 28d is provided outside the opening 24a in the second direction D2 and outside in the fifth direction D5.

  The second flow path member 6 has a plurality of flow paths formed therein, and guides the liquid supplied from the liquid tank to the first flow path member 4. The second flow path member 6 is provided on an outer peripheral portion of the pressurizing chamber surface 4-1 of the first flow path member 4, and an adhesive (not shown) is provided outside the mounting area of the piezoelectric actuator substrate 40. ) Is joined to the first flow path member 4.

(Second channel member (integrated channel))
As shown in FIGS. 4 and 5, the second flow path member 6 has a through hole 6a and openings 6b, 6c, 6d, 22a, 26a. The through hole 6a is formed to extend from the second direction D2 to the fifth direction D5, and is disposed outside the mounting area of the piezoelectric actuator substrate 40. The signal transmission unit 60 is inserted through the through hole 6a.

  The opening 6b is provided on the upper surface of the second flow path member 6, and is disposed at an end of the second flow path member in the second direction D2. The opening 6b supplies the liquid from the liquid tank to the second flow path member 6. The opening 6c is provided on the upper surface of the second flow path member 6, and is disposed at an end of the second flow path member in the fifth direction D5. The opening 6c collects the liquid from the second flow path member 6 to the liquid tank. The opening 6d is provided on the lower surface of the second flow path member 6, and the piezoelectric actuator substrate 40 is arranged in a space formed by the opening 6d.

  The opening 22a is provided on the lower surface of the second flow path member 6, and is provided so as to extend from the second direction D2 to the fifth direction D5. The opening 22a is formed at an end of the second flow path member 6 in the third direction D3, and is provided closer to the third direction D3 than the through hole 6a.

  The opening 22a is in communication with the opening 6b, and forms the first integrated flow path 22 by the opening 22a being sealed by the first flow path member 4. The first integrated channel 22 is formed so as to extend from the second direction D2 to the fifth direction D5, and supplies the liquid to the openings 20a and 28c of the first channel member 4.

  The opening 26a is provided on the lower surface of the second flow path member 6, and is provided so as to extend from the second direction D2 to the fifth direction D5. The opening 26a is formed at an end of the second flow path member 6 in the sixth direction D6, and is provided closer to the sixth direction D6 than the through hole 6a.

  The opening 26a is in communication with the opening 6c, and the opening 26a is sealed by the first flow path member 4, thereby forming the second integrated flow path 26. The second integrated channel 26 is formed to extend from the second direction D2 to the fifth direction D5, and collects liquid from the openings 24a and 28d of the first channel member 4.

  With the above configuration, the liquid supplied from the liquid tank to the opening 6b is supplied to the first integrated flow path 22, flows into the first common flow path 20 via the opening 22a, and the liquid is supplied to the first flow path member 4. Supplied. Then, the liquid recovered by the second common flow path 24 flows into the second integrated flow path 26 through the opening 26a, and the liquid is recovered outside through the opening 6c. Note that the second flow path member 6 does not necessarily have to be provided.

  The supply and recovery of the liquid may be realized by appropriate means. For example, as shown by a dotted line in FIG. 3A, the printer 1 includes a first integrated flow path 22, a circulation flow path 78 including the flow path of the first flow path member 4 and the second integrated flow path 26, and a A flow forming section 79 that forms a flow from the one integrated flow path 22 to the second integrated flow path 26 via the flow path of the first flow path member 4.

  The configuration of the flow forming section 79 may be an appropriate one. For example, the flow forming section 79 includes a pump, and performs suction from the opening 6c and / or discharge to the opening 6b. Further, for example, the flow forming unit 79 includes a collection space for storing the liquid collected from the opening 6c, a supply space for storing the liquid supplied to the opening 6b, and a pump for sending the liquid from the collection space to the supply space. And a pressure difference between the first integrated flow path 22 and the second integrated flow path 26 caused by making the liquid level in the supply space higher than the liquid level in the recovery space. Good.

  The portion of the circulation flow path 78 located outside the first flow path member 4 and the second flow path member 6 and the flow forming section 79 may be a part of the liquid discharge head 2 or the liquid discharge head. 2 may be provided outside.

(First flow path member (common flow path and discharge unit))
As shown in FIGS. 5 to 8, the first flow path member 4 is formed by stacking a plurality of plates 4 a to 4 m, and when viewed in cross section in the stacking direction, a pressurizing chamber provided on the upper side. It has a surface 4-1 and a discharge hole surface 4-2 provided on the lower side. The piezoelectric actuator substrate 40 is placed on the pressurizing chamber surface 4-1, and the liquid is discharged from the discharge holes 8 opened on the discharge hole surface 4-2. The plurality of plates 4a to 4m can be formed of a metal, an alloy, or a resin. The first flow path member 4 may be integrally formed of resin without laminating the plurality of plates 4a to 4m.

  The first flow path member 4 includes a plurality of first common flow paths 20, a plurality of second common flow paths 24, a plurality of end flow paths 28, a plurality of discharge units 15, and a plurality of dummy discharge units 17. Are formed.

  The first common flow path 20 is provided so as to extend from the first direction D1 to the fourth direction D4, and is formed to communicate with the opening 20a. Further, a plurality of the first common flow paths 20 are arranged from the second direction D2 to the fifth direction D5. In addition, the first integrated channel 22 and the plurality of first common channels 20 can be regarded as a manifold, and one first common channel 20 can be regarded as one branch channel of the manifold. . As shown in FIGS. 8A and 8B, the first common flow path 20 is vertically partitioned in a part of the flow path direction. This will be described later.

  The second common flow channel 24 is provided to extend from the fourth direction D4 in the first direction D1, and is formed to communicate with the opening 24a. In addition, a plurality of the second common flow paths 24 are arranged in the second direction D2 to the fifth direction D5, and are disposed between the adjacent first common flow paths 20. Therefore, the first common flow paths 20 and the second common flow paths 24 are alternately arranged from the second direction D2 to the fifth direction D5. The second integrated channel 26 and the plurality of second common channels 24 can be regarded as a manifold, and one second common channel 24 can be regarded as one branch channel of the manifold. .

  A damper 30 is formed in the second common flow path 24 of the first flow path member 4, and a space 32 facing the second common flow path 24 is arranged via the damper 30. The damper 30 has a first damper 30a and a second damper 30b. The space 32 has a first space 32a and a second space 32b. The first space 32a is provided above the second common channel 24 through which the liquid flows via the first damper 30a. The second space 32b is provided below the second common channel 24 through which the liquid flows via the second damper 30b.

  The first damper 30a is formed in substantially the entire area above the second common flow path 24. Therefore, in plan view, the first damper 30a has the same shape as the second common flow path 24. The first space 32a is formed in substantially the entire area above the first damper 30a. Therefore, when viewed in plan, the first space 32a has the same shape as the second common flow path 24.

  The second damper 30b is formed in substantially the entire area below the second common flow path 24. Therefore, in plan view, the second damper 30b has the same shape as the second common flow path 24. The second space 32b is formed in substantially the entire area below the second damper 30b. Therefore, in a plan view, the second space 32b has the same shape as the second common channel 24. Since the first flow path member 4 is provided with the damper 30 in the second common flow path 24, the pressure fluctuation in the second common flow path 24 can be reduced, and fluid crosstalk hardly occurs.

  The first damper 30a and the first space 32a can be formed by forming grooves in the plates 4d and 4e by half etching and joining the grooves so that the grooves face each other. At this time, the remainder left by the half etching of the plate 4e becomes the first damper 30a. Similarly, the second damper 30b and the second space 32b can be manufactured by forming a groove in the plates 4k and 4l by half etching.

  The end flow passages 28 are formed at the end of the first flow passage member 4 in the second direction D2 and at the end of the first flow passage member 4 in the fifth direction D5. The end channel 28 has a wide portion 28a, a narrowed portion 28b, and openings 28c and 28d. The liquid supplied from the opening 28c flows through the wide portion 28a, the narrowed portion 28b, the wide portion 28a, and the opening 28d in this order, and thus flows through the end flow path 28. As a result, the liquid is present in the end flow path 28 and the liquid flows through the end flow path 28, and the temperature of the first flow path member 4 located around the end flow path 28 is made more uniform by the liquid. Is done. Therefore, the possibility of the first flow path member 4 being dissipated from the end in the second direction D2 and the end in the fifth direction D5 is reduced.

(Discharge unit)
The discharge unit 15 will be described with reference to FIGS. The discharge unit 15 includes a discharge hole 8, a pressure chamber 10, a first individual flow path (first flow path) 12, a second individual flow path (second flow path) 14, and a third individual flow path (second flow path). (Third flow path) 16. In the liquid ejection head 2, the liquid is supplied from the first individual channel 12 and the second individual channel 14 to the pressurizing chamber 10, and the third individual channel 16 collects the liquid from the pressurizing chamber 10. . Although details will be described later, the flow resistance of the second individual flow path 14 is lower than the flow resistance of the first individual flow path 12.

  The discharge units 15 are provided between the adjacent first common flow channel 20 and second common flow channel 24, and are formed in a matrix in the plane direction of the first flow channel member 4. The discharge unit 15 has a discharge unit column 15a and a discharge unit row 15b. In the discharge unit row 15a, the discharge units 15 are arranged from the first direction D1 to the fourth direction D4. In the ejection unit row 15b, the ejection units 15 are arranged from the second direction D2 to the fifth direction D5.

  The pressurizing chamber 10 has a pressurizing chamber row 10c and a pressurizing chamber row 10d. Further, the discharge holes 8 have a discharge hole row 8a and a discharge hole row 8b. Similarly, the ejection hole array 8a and the pressure chamber array 10c are arranged from the first direction D1 to the fourth direction D4. Similarly, the ejection hole rows 8b and the pressurizing chamber rows 10d are arranged from the second direction D2 to the fifth direction D5.

  The angle formed by the first direction D1 and the fourth direction D4 and the second direction D2 and the fifth direction D5 is shifted from a right angle. For this reason, the ejection holes 8 belonging to the ejection hole array 8a arranged along the first direction D1 are arranged so as to be shifted in the second direction D2 by the shift from the right angle. Since the ejection hole rows 8a are arranged in the second direction D2, the ejection holes 8 belonging to the different ejection hole rows 8a are displaced in the second direction D2 accordingly. These are combined, and the discharge holes 8 of the first flow path member 4 are arranged at regular intervals in the second direction D2. Thereby, printing can be performed so as to fill a predetermined range with pixels formed by the discharged liquid.

  In FIG. 6, when the ejection holes 8 are projected in the third direction D3 and the sixth direction D6, 32 ejection holes 8 are projected in the range of the virtual straight line R, and each of the ejection holes 8 in the virtual straight line R has an interval of 360 dpi. Line up. Accordingly, if the recording medium P is transported and printed in a direction orthogonal to the virtual straight line R, printing can be performed at a resolution of 360 dpi.

  The dummy discharge unit 17 is provided between the first common flow path 20 located closest to the second direction D2 and the second common flow path 24 located closest to the second direction D2. The dummy discharge unit 17 is also provided between the first common flow path 20 located closest to the fifth direction D5 and the second common flow path 24 located closest to the fifth direction D5. The dummy ejection unit 17 is provided to stabilize the ejection of the ejection unit row 15a located closest to the second direction D2 or the fifth direction D5.

  The pressurizing chamber 10 has a pressurizing chamber main body 10a and a partial flow path 10b, as shown in FIGS. The pressurizing chamber main body 10a has a circular shape in plan view, and the partial flow path 10b extends downward from the pressurizing chamber main body 10a. The pressurizing chamber main body 10a pressurizes the liquid in the partial flow path 10b by receiving pressure from the displacement element 48 provided on the pressurizing chamber main body 10a.

  The pressurizing chamber main body 10a has a substantially disk shape, and has a circular planar shape. Since the planar shape is a circular shape, the displacement amount and the volume change of the pressurizing chamber 10 caused by the displacement can be increased. The partial flow path 10b has a substantially cylindrical shape with a diameter smaller than the pressure chamber main body 10a, and has a circular planar shape. The partial flow path 10b is housed in the pressurizing chamber main body 10a when viewed from the pressurizing chamber surface 4-1.

  The partial flow path 10b may have a conical shape or a truncated conical shape having a smaller cross-sectional area toward the discharge hole 8 side. Thereby, the width of the first common flow path 20 and the second common flow path 24 can be increased, and the difference in pressure loss described above can be reduced.

  The pressurizing chambers 10 are arranged along both sides of the first common flow path 20 and constitute a total of two pressurizing chamber rows 10c, one on each side. The first common channel 20 and the pressurizing chambers 10 arranged on both sides thereof are connected via a first individual channel 12 and a second individual channel 14.

  In addition, the pressurizing chambers 10 are arranged along both sides of the second common flow path 24, and one pressurizing chamber row 10c is arranged on each side. The second common flow channel 24 and the pressurizing chambers 10 arranged on both sides thereof are connected via the third individual flow channel 16.

  The first individual flow path 12, the second individual flow path 14, and the third individual flow path 16 will be described with reference to FIG.

  The first individual flow path 12 connects the first common flow path 20 and the pressurizing chamber main body 10a. The first individual flow channel 12 extends upward from the upper surface of the first common flow channel 20, then extends in the fifth direction D5, extends in the fourth direction D4, and then upward again. It extends and is connected to the lower surface of the pressure chamber main body 10a.

  The second individual flow path 14 connects the first common flow path 20 and the partial flow path 10b. The second individual flow path 14 extends from the lower surface of the first common flow path 20 in the fifth direction D5, extends in the first direction D1, and is connected to the side surface of the partial flow path 10b.

  The third individual flow path 16 connects the second common flow path 24 and the partial flow path 10b. The third individual flow channel 16 extends from the side surface of the second common flow channel 24 in the second direction D2, extends in the fourth direction D4, and is connected to the side surface of the partial flow channel 10b.

  The flow resistance of the second individual flow path 14 is lower than the flow resistance of the first individual flow path 12. In order to make the flow resistance of the second individual flow path 14 lower than the flow resistance of the first individual flow path 12, for example, the thickness of the plate 41 in which the second individual flow path 14 is formed is set to the first individual flow path. What is necessary is just to make it thicker than the thickness of the plate 4c in which the flow path 12 is formed. Further, in plan view, the width of the second individual flow channel 14 may be wider than the width of the first individual flow channel 12. Further, in plan view, the length of the second individual flow path 14 may be shorter than the length of the first individual flow path 12.

  With the above configuration, in the first flow path member 4, the liquid supplied to the first common flow path 20 through the opening 20a is added through the first individual flow path 12 and the second individual flow path 14. The liquid flows into the pressure chamber 10 and a part of the liquid is discharged from the discharge holes 8. Then, the remaining liquid flows from the pressurizing chamber 10 into the second common flow path 24 via the third individual flow path 16 and from the first flow path member 4 to the second flow path member 6 via the opening 24a. Is discharged.

(Piezoelectric actuator)
The piezoelectric actuator substrate 40 will be described with reference to FIGS. The piezoelectric actuator substrate 40 including the displacement elements 48 is joined to the upper surface of the first flow path member 4, and each displacement element 48 is arranged so as to be located on the pressurizing chamber 10. The piezoelectric actuator substrate 40 occupies a region having substantially the same shape as the pressurizing chamber group formed by the pressurizing chamber 10. The opening of each pressure chamber 10 is closed by joining the piezoelectric actuator substrate 40 to the pressure chamber surface 4-1 of the first flow path member 4.

  The piezoelectric actuator substrate 40 has a laminated structure including two piezoelectric ceramic layers 40a and 40b that are piezoelectric bodies. Each of these piezoelectric ceramic layers 40a and 40b has a thickness of about 20 μm. Each of the piezoelectric ceramic layers 40a and 40b extends so as to straddle the plurality of pressure chambers 10.

The piezoelectric ceramic layers 40a, 40b may, for example, strength with a dielectric, lead zirconate titanate (PZT), NaNbO ₃ system, BaTiO ₃ system, (BiNa) NbO ₃ system, such as BiNaNb ₅ O ₁₅ system Made of ceramic material. The piezoelectric ceramic layer 40b functions as a vibration plate, and does not necessarily need to be a piezoelectric body. Instead, another ceramic layer other than a piezoelectric body, a metal plate, or a resin plate may be used. The diaphragm may be configured as if it were also used as a member constituting a part of the first flow path member 4. For example, unlike the illustrated example, the diaphragm may have a size that covers the entire pressure chamber surface 4-1 and may have openings facing the openings 20a, 24a, 28c, and 28d.

  On the piezoelectric actuator substrate 40, a common electrode 42, individual electrodes 44, and connection electrodes 46 are formed. The common electrode 42 is formed in a region between the piezoelectric ceramic layer 40a and the piezoelectric ceramic layer 40b over substantially the entire surface in the surface direction. The individual electrodes 44 are arranged on the upper surface of the piezoelectric actuator substrate 40 at positions facing the pressurizing chamber 10.

  A portion of the piezoelectric ceramic layer 40a sandwiched between the individual electrode 44 and the common electrode 42 is polarized in the thickness direction, and becomes a displacement element 48 having a unimorph structure that is displaced when a voltage is applied to the individual electrode 44. I have. Therefore, the piezoelectric actuator substrate 40 has a plurality of displacement elements 48.

  The common electrode 42 can be formed of a metal material such as Ag-Pd, and the thickness of the common electrode 42 can be about 2 μm. The common electrode 42 is connected to a common electrode surface electrode (not shown) on the piezoelectric ceramic layer 40a via a via hole formed through the piezoelectric ceramic layer 40a, and is grounded via the common electrode surface electrode. , And is held at the ground potential.

  The individual electrode 44 is formed of a metal material such as Au and has an individual electrode main body 44a and an extraction electrode 44b. As shown in FIG. 7C, the individual electrode main body 44a is formed in a substantially circular shape in plan view, and is formed smaller than the pressurizing chamber main body 10a. The extraction electrode 44b is extracted from the individual electrode body 44a, and the connection electrode 46 is formed on the extracted extraction electrode 44b.

  The connection electrode 46 is made of, for example, silver-palladium containing glass frit and has a thickness of about 15 μm and is formed in a convex shape. The connection electrode 46 is electrically connected to an electrode provided on the signal transmission unit 60.

  The liquid ejection head 2 displaces the displacement element 48 according to a drive signal supplied to the individual electrode 44 via the driver IC 62 or the like under the control of the control unit 76. As a driving method, a so-called pull driving can be used.

(Details and operation of the discharge unit)
The ejection unit 15 of the liquid ejection head 2 will be described in detail with reference to FIG.

  The discharge unit 15 includes a discharge hole 8, a pressure chamber 10, a first individual flow path (first flow path) 12, a second individual flow path (second flow path) 14, and a third individual flow path (second flow path). (Third flow path) 16. The first individual channel 12 and the second individual channel 14 are connected to a first common channel 20 (fourth channel (see FIG. 8)), and the third individual channel 16 is connected to a second common channel. It is connected to the passage 24 (fifth passage (see FIG. 8)).

  The first individual flow path 12 is connected to the first direction D <b> 1 side of the pressurizing chamber main body 10 a in the pressurizing chamber 10. The second individual flow path 14 is connected to the partial direction 10b of the pressurized chamber 10 in the fourth direction D4. The third individual flow path 16 is connected to the first direction D1 side of the partial flow path 10b in the pressurizing chamber 10.

  The liquid supplied from the first individual flow path 12 flows downward through the partial flow path 10b through the pressurizing chamber main body 10a, and a part of the liquid is discharged from the discharge hole 8. The liquid not discharged from the discharge holes 8 is collected outside the discharge unit 15 via the third individual flow path 16.

  Part of the liquid supplied from the second individual flow path 14 is discharged from the discharge holes 8. The liquid that has not been discharged from the discharge hole 8 flows upward in the partial flow path 10b, and is collected outside the discharge unit 15 through the third individual flow path 16.

  As shown in FIG. 9, the liquid supplied from the first individual flow channel 12 flows through the pressurizing chamber main body 10a and the partial flow channel 10b, and is discharged from the discharge hole 8. The flow of the liquid in the conventional discharge unit flows substantially linearly from the center of the pressurizing chamber main body 10a toward the discharge hole 8 as indicated by a broken line.

  When such a flow occurs, the liquid hardly flows in the vicinity of the region 80 of the pressurizing chamber 10 which is located on the opposite side to the portion to which the second individual flow path 14 is connected. There is a possibility that a region where the liquid stays may be generated.

  On the other hand, in the discharge unit 15, the first individual flow path 12 and the second individual flow path 14 are connected to the pressurizing chamber 10, and the liquid is supplied to the pressurizing chamber 10 from these flow paths.

  Therefore, the flow of the liquid supplied from the second individual flow path 14 to the pressurizing chamber 10 can collide with the flow of the liquid supplied from the first individual flow path 12 to the discharge hole 8. This makes it difficult for the liquid supplied from the pressurizing chamber 10 to flow to the discharge holes 8 to flow uniformly and substantially linearly, thereby making it difficult to generate a region where the liquid stays in the pressurizing chamber 10.

  That is, the position of the stagnation point of the liquid generated by the flow of the liquid supplied from the pressurizing chamber 10 to the discharge hole 8 moves due to the collision with the flow of the liquid supplied from the pressurizing chamber 10 to the discharge hole 8. Thus, a region where the liquid stays in the pressurizing chamber 10 can be hardly generated.

  The pressurizing chamber 10 has a pressurizing chamber main body 10a and a partial flow path 10b, the first individual flow path 12 is connected to the pressurizing chamber main body 10a, and the second individual flow path 14 is a partial flow path. 10b. Therefore, the first individual channel 12 supplies the liquid so as to flow through the entire pressurizing chamber 10, and the region where the liquid stays in the partial channel 10 b due to the flow of the liquid supplied from the second individual channel 14. Is less likely to occur.

  In addition, the third individual flow path 16 is connected to the partial flow path 10b. Therefore, the flow of the liquid flowing from the second individual flow path 14 to the third individual flow path 16 crosses the inside of the partial flow path 10b. As a result, the liquid flowing from the second individual flow path 14 to the third individual flow path 16 can be made to flow across the flow of the liquid supplied from the pressurizing chamber main body 10a to the discharge hole 8. Therefore, a region in which the liquid stays is less likely to be generated in the partial flow path 10b.

(Details and operation of individual flow paths, etc.)
Further, the third individual flow path 16 is connected to the partial flow path 10b, and is connected to the pressurizing chamber main body 10a side with respect to the second individual flow path 14. Therefore, even when air bubbles enter the inside of the partial flow path 10b from the discharge hole 8, the air bubbles can be discharged to the third individual flow path 16 using the buoyancy of the air bubbles. This can reduce the possibility that the stagnation of bubbles in the partial flow path 10b affects the pressure transmission to the liquid.

  When viewed in a plan view, the first individual flow path 12 is connected to the first direction D1 side of the pressurizing chamber main body 10a, and the second individual flow path 14 is connected to the fourth direction D4 side of the partial flow path 10b. It is connected.

  Therefore, when viewed in a plan view, the liquid is supplied to the ejection unit 15 from both sides in the first direction D1 and the fourth direction D4. Therefore, the supplied liquid has a velocity component in the first direction D1 and a velocity component in the fourth direction D4. Therefore, the liquid supplied to the pressurizing chamber 10 agitates the liquid inside the partial flow path 10b. As a result, a region where the liquid stays is less likely to be generated in the partial flow path 10b.

  Further, the third individual flow path 16 is connected to the first direction D1 side of the partial flow path 10b, and the discharge hole 8 is arranged on the fourth direction D4 side of the partial flow path 10b. This allows the liquid to flow also in the first direction D1 side of the partial flow path 10b, and makes it difficult to generate a region where the liquid stays inside the partial flow path 10b.

  The third individual flow channel 16 may be connected to the partial flow channel 10b on the fourth direction D4 side, and the discharge hole 8 may be arranged on the partial flow channel 10b on the first direction D1 side. In that case, the same effect can be obtained.

  As shown in FIG. 8, the third individual flow path 16 is connected to the second common flow path 24 on the side of the pressurizing chamber main body 10a. Thereby, the air bubbles discharged from the partial flow path 10b can flow along the upper surface of the second common flow path 24. Thereby, it is easy to discharge air bubbles from the second common channel 24 to the outside via the opening 24a (see FIG. 6).

  Further, it is preferable that the upper surface of the third individual flow channel 16 and the upper surface of the second common flow channel 24 are flush. Thereby, the air bubbles discharged from the partial flow path 10b flow along the upper surface of the third individual flow path 16 and the upper surface of the second common flow path 24, and are further easily discharged to the outside.

  Further, the second individual flow channel 14 is connected to the discharge hole 8 side of the partial flow channel 10b with respect to the third individual flow channel 16. As a result, the liquid is supplied from the second individual flow channel 14 in the vicinity of the ejection hole 8. Therefore, the flow velocity of the liquid in the vicinity of the ejection hole 8 can be increased, the pigment and the like contained in the liquid are suppressed from settling, and the ejection hole 8 is less likely to be clogged.

  Further, as shown in FIG. 7B, when viewed in a plan view, the first individual flow path 12 is connected to the first direction D1 side of the pressurizing chamber main body 10a, and the area centroid of the partial flow path 10b. Are located on the fourth direction D4 side with respect to the area center of gravity of the pressurizing chamber main body 10a. That is, the partial flow path 10b is connected to a side of the pressurizing chamber main body 10a far from the first individual flow path 12.

  The area centroid of a plane figure is the center of gravity of a plane figure when a plate-shaped object whose plane shape is the same as that of the plane figure is made of a substance with a uniform mass per unit area. It is a point located at. This area center of gravity is obtained by drawing a first straight line that bisects the area of the plane figure and a second straight line that divides the area of the plane figure into two equal parts and has an angle different from the first straight line. It is also the intersection of the first straight line and the second straight line.

  Thus, the liquid supplied to the first direction D1 side of the pressurizing chamber main body 10a is supplied to the partial flow path 10b after spreading over the entire area of the pressurizing chamber main body 10a. As a result, a region in which the liquid stays is less likely to be generated inside the pressurizing chamber main body 10a.

  Further, the discharge holes 8 are arranged between the second individual flow path 14 and the third individual flow path 16 when viewed in plan. Thereby, when the liquid is discharged from the discharge hole 8, the flow of the liquid supplied from the pressurizing chamber main body 10 a to the discharge hole 8 collides with the flow of the liquid supplied from the second individual flow path 14. The position can be moved.

  That is, the discharge amount of the liquid from the discharge holes 8 differs depending on the image to be printed, and the behavior of the liquid inside the partial flow path 10b changes as the discharge amount of the liquid increases or decreases. Therefore, the position where the flow of the liquid supplied from the pressurizing chamber main body 10a to the discharge hole 8 and the flow of the liquid supplied from the second individual flow path 14 collide due to the increase and decrease of the discharge amount of the liquid moves. Thus, a region where the liquid stays inside the partial flow path 10b is less likely to be generated.

  The area center of gravity of the discharge hole 8 is located on the fourth direction D4 side with respect to the area center of gravity of the partial flow path 10b. As a result, the liquid supplied to the partial flow path 10b spreads over the entire area of the partial flow path 10b and is then supplied to the discharge holes 8, so that a region in which the liquid stays inside the partial flow path 10b is less likely to occur. Become.

  Here, the discharge unit 15 is connected to the first common flow path 20 (fourth flow path) via the first individual flow path 12 (first flow path) and the second individual flow path 14 (second flow path). Have been. Therefore, a part of the pressure applied to the pressurizing chamber main body 10 a is transmitted to the first common channel 20 via the first individual channel 12 and the second individual channel 14.

  When the pressure wave propagates from the first individual flow path 12 and the second individual flow path 14 to the first common flow path 20 and a pressure difference is generated inside the first common flow path 20, the first common flow path The behavior of the liquid in the passage 20 may be unstable. Therefore, it is preferable that the magnitude of the pressure wave transmitted to the first common flow path 20 is uniform.

  In the liquid discharge head 2, the second individual flow path 14 is disposed below the first individual flow path 12 in a cross-sectional view. Therefore, the distance from the pressurizing chamber main body 10 a is longer in the second individual flow path 14 than in the first individual flow path 12, and when the power is transmitted to the second individual flow path 14, pressure attenuation occurs. Become.

  Since the flow resistance of the second individual flow path 14 is lower than the flow resistance of the first individual flow path 12, the pressure attenuation when flowing through the second individual flow path 14 is reduced by the first individual flow path. It can be smaller than the pressure decay when flowing through the passage 12. As a result, the magnitude of the pressure wave propagated from the first individual flow path 12 and the second individual flow path 14 can be made uniform.

  That is, the sum of the pressure attenuation from the pressurizing chamber main body 10a to the first individual flow path 12 or the second individual flow path 14 and the pressure attenuation when flowing through the first individual flow path 12 or the second individual flow path 14 is calculated. In addition, the first individual flow path 12 and the second individual flow path 14 can be made closer to uniform, and the magnitude of the pressure wave transmitted to the first common flow path 20 can be made closer to uniform.

  Further, the third individual flow path 16 is disposed higher than the second individual flow path 14 and lower than the first individual flow path 12 in a cross-sectional view. In other words, the third individual channel 16 is arranged between the first individual channel 12 and the second individual channel 14. Therefore, when the pressure applied to the pressurizing chamber main body 10 a is transmitted to the second individual flow path 14, a part of the pressure is transmitted to the third individual flow path 16.

  On the other hand, the flow resistance of the second individual flow path 14 is lower than the flow resistance of the first individual flow path 12. Therefore, even if the pressure wave reaching the second individual flow path 14 is reduced, the pressure attenuation in the second individual flow path 14 is reduced, and the transmission from the first individual flow path 12 and the second individual flow path 14 is performed. It is possible to make the size of the pressure wave close to uniform.

  The channel resistance of the first individual channel 12 can be 1.03 to 2.5 times the channel resistance of the second individual channel 14.

  The flow resistance of the second individual flow path 14 may be greater than the flow resistance of the first individual flow path 12. In that case, pressure transmission from the first common flow path 20 via the second individual flow path 14 can be made difficult to occur. As a result, it is possible to reduce the possibility that unnecessary pressure is transmitted to the discharge holes 8.

  The channel resistance of the second individual channel 14 can be 1.03 to 2.5 times the channel resistance of the first individual channel 12.

(Partition part)
As shown in FIGS. 8A and 8B, the inside of the first common flow path 20 (fourth flow path) is partitioned into a first section 20e and a second section 20f by a partition section 25. I have. The first section 20e and the second section 20f are located on one side and the other side in a direction intersecting with the first common flow path 20 (vertical direction in the present embodiment). It extends in parallel in the road direction. The plurality of first individual flow paths 12 (first flow paths) are connected to the first section 20e. The plurality of second individual flow paths 14 (second flow paths) are connected to the second section 20f.

  Therefore, for example, a unique problem caused by providing three individual flow paths to optimize the flow in the pressurizing chamber 10 can be solved. Specifically, for example, it is as follows.

  As a result of the provision of the three individual channels, the first individual channel 12 and the second individual channel 14 are commonly connected to the first common channel 20. Therefore, the pressure wave generated in the pressurizing chamber 10 propagates to the first common flow path 20 via the first individual flow path 12 and the first common flow path 20 via the second individual flow path 14. Propagate to Since the first individual flow path 12 and the second individual flow path 14 have different shapes, the pressure wave passing through the first individual flow path 12 and the pressure wave passing through the second individual flow path 14 have different properties. Are different from each other. As a result, when the two pressure waves are mixed in the first common flow path 20, vibration (pressure wave) of an unexpected mode may appear. Then, this pressure wave may propagate to the pressurizing chamber 10 via the first individual flow path 12 and / or the second individual flow path 14 and affect the liquid ejection characteristics. That is, there is a possibility that so-called fluid crosstalk may occur in the adjacent discharge units 15 via the first common flow path 20.

  However, by dividing the inside of the first common flow path 20 into a first section 20e to which the first individual flow path 12 is connected and a second section 20f to which the second individual flow path 14 is connected, for example, Mixing of pressure waves as described above is less likely to occur. As a result, for example, the accuracy of the liquid ejection characteristics is improved. Further, for example, it is expected that each pressure wave is reduced by absorbing the energy of the pressure wave by the elastic deformation of the partition portion 25.

  The first common flow path 20 extends in a direction orthogonal to the opening direction of the plurality of ejection holes 8. For example, the first section 20e and the second section 20f are partitioned by the partition section 25 into one side and the other side in the opening direction (vertical direction) of the discharge hole 8. Specifically, for example, the first section 20e is located above (the side of the pressure chamber 10 with respect to the discharge hole 8), and the second section 20f is located below (the side of the discharge hole 8 with respect to the pressure chamber 10). ing.

  Therefore, for example, the first individual flow path 12 and the second individual flow path 14 connected to different positions in the vertical direction with respect to the pressurization chamber 10 in order to make the flow in the pressurization chamber 10 suitable are relatively formed. It can be extended to the first section 20e and the second section 20f with a simple shape. Further, as described below, it is easy to form the partition part 25 by the plate constituting the first common channel 20.

  The first flow path member 4 includes a plurality of plates 4a to 4m stacked in the direction in which the discharge holes 8 are opened. The partition part 25 is constituted by, for example, one of them (the plate 4i in the illustrated example).

  Therefore, for example, as will be understood from comparison with a modified example (FIG. 11C) described later, the design of the planar shape for forming the partition portion 25 may be changed only for the plate 4i. Further, there is no need to bond a plurality of plates in the partition 25. Therefore, formation of the partition part 25 is easy.

  In the plate 4i constituting the partition part 25, the thickness of the partition part 25 is, for example, smaller than the thickness of at least some other regions. The other region is, for example, a region where both surfaces of the plate 4i are bonded to the other plates (4h and 4j). The thickness of the other region is, for example, the maximum thickness of the plate 4i.

  Therefore, for example, the volume of the first section 20e and / or the second section 20f can be increased by the amount by which the partition section 25 is thinner than other areas. As a result, for example, it is easy to disperse and attenuate the pressure waves in the first common channel 20. Note that such a thin shape in the partition 25 can be easily realized by, for example, performing half-etching on a region to be the partition 25 before the plate 4i is bonded.

  The thickness of the partition 25 is, for example, smaller than the thickness of another region (the region to be bonded). Therefore, by having a predetermined thickness in the other region, it is possible to have high rigidity against an external force generated at the time of bonding, and to maintain the strength of the plate 4i forming the other region. Further, since the partition 25 is thin, the rigidity of the partition 25 can be reduced, and the partition 25 can be easily deformed.

  As understood from the lines VIIIa-VIIIa and VIIIb-VIIIb in FIG. 7 (b), in FIGS. 8 (a) and 8 (b), only the portion of the partition 25 in the second direction D2 is located. Although shown, the portion in the fifth direction D5 is the same as that in FIG. That is, the partition 25 extends from the wall surface of the first common flow path 20 on the second direction D2 side to the wall surface of the first common flow path 20 on the fifth direction D5 side, and is entirely formed by a half-etched region of the plate 4i. It is configured.

  The material of the plate 4i constituting the partition 25 may be metal or resin. In the case of resin, for example, compared to metal, the energy of the pressure wave is easily absorbed by its compression. Further, the specific thickness and the vertical position of the partition 25 may be appropriately set.

  The range of the partition 25 in the flow direction of the first common flow path 20 will be described with reference to FIGS. 10A and 10B. FIG. 10A is a schematic plan view showing one first common flow path 20 and one second common flow path 24, and a plurality of discharge units 15 located therebetween. Here, in order to facilitate understanding, the plurality of ejection units 15 are shown in a small number, and the shape of each ejection unit 15 is schematically shown. Two dotted lines extending vertically in FIG. 10A and FIG. 10B indicate the same position between the drawings in the first direction D1.

  The partition 25 is located in a range CR1 where the plurality of first individual channels 12 and the plurality of second individual channels 14 are connected in the channel direction of the first common channel 20. Here, the plurality of first individual flow paths 12 and the plurality of second individual flow paths 14 are, for example, all the discharge units 15 connected to the first common flow path 20 (for example, as shown in FIG. The first individual flow path 12 and the second individual flow path 14 of all the discharge units 15) of the two discharge unit rows 15a on both sides of the common flow path 20.

  On the other hand, the partition 25 is not located on the end side of the first common flow path 20 beyond the range CR1. That is, the first common flow path 20 is not partitioned at both ends or one end (both ends in the illustrated example). Therefore, the first section 20 e and the second section 20 f communicate with each other at the end of the first common channel 20. Further, the partition 25 is separated from the opening 20a to the range CR1 side.

  As described above, the first section 20e and the second section 20f are in communication.

  Therefore, for example, excess and deficiency of the liquid between the first section 20e and the second section 20f can be reduced. Thereby, for example, the possibility that an unintended pressure difference occurs between the first section 20e and the second section 20f or the possibility that the pressure in any of the sections becomes an unintended pressure is reduced. As a result, the possibility that the influence of the first individual flow path 12 and the second individual flow path 14 on the flow in the pressurizing chamber 10 becomes unintended is reduced.

  Further, for example, in the flow direction of the first common flow path 20, the partitioning section 25 connects the plurality of first individual flow paths 12 and the plurality of second individual flow paths 14 to the first common flow path 20. Is located in a range CR1 (first range).

  Therefore, for example, mixing of the pressure waves propagating from the first individual flow channel 12 and the second individual flow channel 14 can be suppressed more reliably.

  In addition, the partition 25 is, for example, separated from the opening 20 a of the first common channel 20 in the channel direction of the first common channel 20. In other words, there is a gap between the partition 25 and the opening 20a when viewed in a direction orthogonal to the flow path direction.

  Accordingly, for example, the possibility that the partition 25 becomes a resistance to the flow from the opening 20a into the first common flow path 20 is reduced. Further, the pressure waves in both the first section 20 e and the second section 20 f can be released from the opening 20 a of the first common flow path 20. Even if the pressure waves are mixed in the vicinity of the opening 20a, there is less possibility that the pressure waves in the unintended mode will affect the discharge characteristics as compared with the case where the pressure waves are mixed in the range CR1. The size of the gap may be appropriately set.

  The first flow path member 4 may have a connection path 27 shown in FIG. The connection path 27 connects the end side of the first common flow path 20 beyond the range CR1 and the end side of the second common flow path 24 beyond the range CR2. The range CR1 is as described above. The range CR2 is a range in which the plurality of third individual flow paths 16 are connected to the second common flow path 24. The plurality of third individual flow paths 16 referred to here are, for example, all the discharge units 15 connected to the second common flow path 24 (for example, as shown in FIG. 6, two rows on both sides of the second common flow path 24). The third individual flow path 16 of all the discharge units 15) of the discharge unit row 15a.

  By providing such a connection path 27, an end portion on the downstream side (the fourth direction D4 side) of the range CR1 of the first common flow path 20 and an upstream side of the range CR2 of the second common flow path 24 are provided. At the end (the first direction D1 side), the possibility that the liquid stays is reduced. The cross-sectional area of the connection path 27 may be, for example, smaller than the cross-sectional area of the common flow path, and may be smaller, equal, or larger than the cross-sectional area of the individual flow path. The shape of the connection path 27 and the connection position (upper surface, side surface, or lower surface) to the common flow path are also arbitrary.

  The partition part 25 is located, for example, on the range CR1 side of the connection path 27. That is, the first common flow path 20 is not partitioned at the position of the connection path 27.

  Therefore, for example, the flow due to the provision of the connection path 27 reduces the possibility of stagnation on both the first section 20e side and the second section 20f side. As in the case of the vicinity of the opening 20a, even when the pressure wave is mixed in the vicinity of the connection path 27, the pressure wave in an unintended mode affects the discharge characteristics as compared with the case where the pressure wave is mixed in the range CR1. The fear is low.

(Modification)
FIG. 11A is a schematic perspective view showing a part of a partition 225 according to a modification.

  The partition 225 has a plurality of holes 225h communicating the first section 20e and the second section 20f. This modification is the same as the embodiment except that, for example, a hole 225h is provided.

  By the communication between the first section 20e and the second section 20f, for example, as described above, excess and deficiency of the liquid between the first section 20e and the second section 20f is reduced, and an unintended pressure difference is generated. And the like are less likely to occur.

  For example, all or a part of the plurality of holes 225h is located in the range CR1. Thereby, for example, an effect of alleviating the excess or deficiency of the liquid between the first section 20e and the second section 20f at the entire first common channel 20 or at an arbitrary position is exerted.

  The positions, sizes, and shapes of the plurality of holes 225h may be appropriately set. For example, the plurality of holes 225h are provided in one row or a plurality of rows over the entire range CR1 along the first common flow path 20 at the same pitch as the pitch of the discharge units 15 in one discharge unit row 15a. I have. By doing so, the plurality of holes 225h can be uniformly distributed in the range CR1, and the above-described effects can be obtained without bias. Further, for example, the shape of the hole 225h may be a circle, an ellipse, or a polygon (for example, a rectangle), or a slit extending in the flow direction or the width direction.

  The holes 225h are formed, for example, when the planar shape of the plate 4i constituting the partition 225 is formed by etching.

  FIG. 11B is a cross-sectional view of a partition 325 according to another modification example, which is orthogonal to the flow direction of the first common flow channel 320. Note that this modification is the same as the embodiment except for the cross-sectional shape of the partition, for example.

  The first common channel 320 is the same as the first common channel 20 of the embodiment. The partition 325 divides the first common channel 320 into a first section 320e and a second section 320f, as in the embodiment. However, the partition 325 has a space 325s inside. Further, from another viewpoint, the partition portion 325 is not constituted by one plate, but is constituted by two or more (two in the illustrated example) plates.

  Specifically, the inner wall of the first common channel 320 is formed by stacking plates 304a to 304f. The partition 325 is constituted by, for example, two plates 304c and 304d which are adhered to each other. The sides of the plates 304c and 304d facing each other in the region located in the first common flow channel 320 are dug by half etching to thereby form a space 325s. In the space 325s, for example, a gas (for example, air) is sealed.

  Thus, in this modification, the space 325s is formed inside the partition 325. Therefore, for example, the energy of the pressure wave can be absorbed by the compression of the gas in the space 325s. As a result, for example, the possibility that the pressure wave that has passed through the first individual flow path 12 and the pressure wave that has passed through the second individual flow path 14 are mixed and affect the ejection characteristics is reduced more reliably.

  Note that a space may be formed between two plates with another plate interposed therebetween. In this case, half-etching may or may not be performed. Further, in two plates adhered to each other or with another plate interposed therebetween, half etching may be performed only on one of the plates, and half etching may be performed on the side opposite to the space. . Further, a partition may be formed by three or more plates, and a plurality of spaces may be stacked in the partition. In the space, instead of gas, a liquid that is more compressible than the liquid flowing through the first section 20e and the second section 20f may be sealed, or a member that is more compressible than the material of the plate may be arranged. Good.

  FIG. 11C is a cross-sectional view of a partition 425 according to still another modification example, which is orthogonal to the flow direction of the first common flow path 420. This modified example is basically the same as the embodiment, except for the cross-sectional shape of the partition.

  The first common channel 420 is the same as the first common channel 20 of the embodiment. The partition portion 425 does not partition the first common flow channel 420 in the vertical direction (the stacking direction of the plates, the opening direction of the discharge holes 8), but the width direction of the first common flow channel 420 (the flow direction and the discharge holes). 8 (a direction orthogonal to the opening direction). And the 1st individual channel 12 is connected to the 1st section 420e, and the 2nd individual channel 14 is connected to the 2nd section 420f.

  More specifically, for example, the first flow path member 404 is configured by stacking plates 404a to 404m. The inner wall of the first common channel 20 is constituted by plates 404d to 404j. In the plates 404d to 404j, a slit serving as the first common flow path 420 is formed by etching, except for a region serving as the partition 425. Then, the remaining area is laminated and adhered to form the partition section 425.

  When the partition 425 is separated from both ends of the first common flow channel 420 as in the embodiment, the region serving as the partition 425 is located in the slit serving as the first common flow channel 20 in each plate. It is formed in a shape. Therefore, in the plates 404d to 404j, for example, a connecting portion that connects the region serving as the partition 425 and the outside of the slit is formed at a position where they do not overlap with each other.

  The first individual flow path 12 and the second individual flow path 14 are operable except that the length in the width direction of the first common flow path 420 is set so as to be connectable to the first section 420e and the second section 420f, respectively. Same as the form.

  As described above, in the present modified example, the first section 420e and the second section 420f are partitioned by the partition section 425 into one side and the other side in the width direction of the first common flow path 420. Therefore, for example, the first section 420e and the second section 420f have the same position in the depth direction of the first common flow channel 420, and the effects of gravity are equal. As a result, for example, the liquid on the upstream side of the partition 425 easily flows into the first section 420e and the second section 420f without bias.

  In addition, since the partition 425 is formed by laminating a part of the planar shape of the plate, for example, the planar shape of the partition 425 can be easily adjusted by appropriately setting the planar shape of the plate to an appropriate shape. Things. For example, in plan view, depending on the arrangement of the connection positions of the first individual flow channel 12 and the second individual flow channel 14 with respect to the first common flow channel 420, the partition 425 may meander, or the width of the partition 425 may be periodically changed. Can be changed. As a result, for example, it is expected that the mixing of the pressure waves is more effectively suppressed.

  Note that, in the above embodiment and modified examples, the displacement element 48 is an example of a pressing unit. The transport rollers 74a to 74d are an example of a transport unit. The opening 20a is an example of the inflow port of the fourth flow path. The range CR1 is an example of a first range. The range CR2 is an example of a second range.

  The aspects of the present disclosure are not limited to the above embodiments, and various changes can be made without departing from the gist of the embodiments.

  The configuration of the flow path connected to the pressurizing chamber and supplied or collected for the liquid is not limited to the one exemplified in the embodiment. For example, in FIG. 9, the direction extending from the partial flow path 10b of the second individual flow path 14 and / or the third individual flow path 16 may be reversed from that illustrated. Further, for example, the liquid may be supplied to the pressurizing chamber 10 from the first individual channel 12 and the third individual channel 16 and the liquid may be collected from the second individual channel 14. The first individual flow channel 12 may be used for collecting a liquid.

  In the embodiment, the first flow path and the second flow path (the first individual flow path 12 and the second individual flow path 14 in the embodiment) commonly connected to the fourth flow path both apply liquid. The flow path was supplied to the pressure chamber. However, the first flow path and the second flow path may be flow paths for collecting a liquid from the pressurized chamber. For example, liquid is supplied from the first common channel 20 to the pressurizing chamber 10 via the first individual channel 12, and from the pressurizing chamber 10 via the second individual channel 14 and the third individual channel 16. Thus, the liquid may be collected in the second common channel 24.

  In this case, the liquid supplied from the first individual flow channel 12 to the pressurizing chamber 10 generates a flow to the second individual flow channel 14 and a flow to the third individual flow channel 16. Thereby, for example, stagnation in the pressurized chamber 10 is suppressed. In this case, the second individual channel 14 is an example of a first channel, the third individual channel 16 is an example of a second channel, and the first individual channel 12 is an example of a third channel. The second common flow path 24 is an example of a fourth flow path, the first common flow path 20 is an example of a fifth flow path, and the opening 24a is an example of an outlet of the fourth flow path.

  In the embodiment, the width (in the direction orthogonal to the first direction D1) of the individual flow paths (for example, the second individual flow path 14 and the third individual flow path 16) connected to the partial flow path 10b is a plan view. The diameter was smaller than the diameter of the flow path 10b. However, the width of these individual flow paths may be made equal to or greater than the diameter of the partial flow path 10b, for example, by increasing the width at the connection portion with the partial flow path 10b.

  The partition part may be solid as shown in the embodiment and the modified example of FIG. 11C, or may be a hollow in which the liquid to be discharged does not flow as shown in the modified example of FIG. It may be. In the modification of FIG. 11C, the inside can be made hollow.

  Further, as understood from the modified example of FIG. 11A, the partition portion is configured so that the fourth flow path (the first common flow path 20 in the embodiment) intersects with the flow direction (the width in the embodiment). It is not necessary to partition over the entire direction (in the thickness direction in the modified example of FIG. 11C), and the first section and the second section may be partially connected. Therefore, for example, the partition part may be formed in a mesh shape with a plurality of holes distributed two-dimensionally regularly or irregularly, or may be formed in a longitudinal direction (the flow direction of the fourth flow path). It may have a slit extending partially or entirely.

  All the discharge units connected to one fourth flow path (one first common flow path 20 in the embodiment) (two discharge unit rows 15a on both sides of the first common flow path 20 in the embodiment) For all the discharge units 15), the first channel (the first individual channel 12 in the embodiment) is connected to the first section, and the second channel (the second individual channel 14 in the embodiment) is connected to the second section. It does not need to be connected to The partitioning part contributes to, for example, reducing mixing of pressure waves propagating from the same pressurized chamber via the first flow path and the second flow path to the fourth flow path. Therefore, for at least a part of the discharge units, when the first flow path is connected to the first section and the second flow path is connected to the second section, as compared to the case where no partition is provided. In addition, the mixing of pressure waves is suppressed, and the accuracy of ejection characteristics is improved. For example, in two discharge unit rows located on both sides of one fourth flow path, for one discharge unit row, the first flow path is connected to the first partition, and the second flow path is connected to the second partition. And the other discharge unit row, the second flow path may be connected to the first section, and the first flow path may be connected to the second section.

DESCRIPTION OF SYMBOLS 1 ... Color inkjet printer 2 ... Liquid discharge head 2a ... Head main body 4 ... 1st flow path member 4a-4m ... Plate 4-1 ... Pressurization chamber surface 4-2. ..Discharge hole surface 6 ... Second flow path member 8 ... Discharge hole 10 ... Pressure chamber 10a ... Pressure chamber main body 10b ... Partial flow path 12 ... First individual flow Road (first flow path)
14... Second individual flow path (second flow path)
15 ... Discharge unit 16 ... Third individual flow path (third flow path)
20: first common flow path (fourth flow path)
20a ... Opening (inlet)
22: first integrated flow path 24: second common flow path (fifth flow path)
24a ... opening (outflow port)
25 partition part 26 second integrated flow path 28 end flow path 30 damper 32 damper chamber 40 piezoelectric actuator substrate 42 common electrode 44・ Individual electrode 46 ・ ・ ・ Connection electrode 48 ・ ・ ・ Displacement element 50 ・ ・ ・ Housing 52 ・ ・ ・ Heat radiation plate 54 ・ ・ ・ Wiring board 56 ・ ・ ・ Pressing member 58 ・ ・ ・ Elastic member 60 ・ ・ ・ Signal Transmission unit 62: Driver IC
70: Head mounting frame 72: Head group 74a, 74b, 74c, 74d: Conveying roller 76: Control unit P: Recording medium D1: First direction D2: Second Direction D3: Third direction D4: Fourth direction D5: Fifth direction D6: Sixth direction

Claims (12)

Multiple discharge holes,
A plurality of pressure chambers connected to the plurality of discharge holes, respectively;
A plurality of first flow paths respectively connected to the plurality of pressurizing chambers,
A plurality of second flow paths respectively connected to the plurality of pressurizing chambers,
A plurality of third flow paths respectively connected to the plurality of pressure chambers;
A fourth flow path commonly connected to the plurality of first flow paths and the plurality of second flow paths, and a fifth flow path commonly connected to the plurality of third flow paths. A channel member provided,
A plurality of pressurizing units for pressurizing the liquids in the plurality of pressurized chambers, respectively,
The flow path member further includes a partition section that partitions the inside of the fourth flow path into a first section on one side and a second section on the other side in a direction intersecting the flow direction of the fourth flow path. Equipped,
The plurality of first flow paths are connected to the first section,
The plurality of second flow paths are connected to the second section. The fourth flow path extends in a direction orthogonal to an opening direction of the plurality of discharge holes,
The liquid ejection head according to claim 1, wherein the first section and the second section are partitioned by the partition into one side and the other side in an opening direction of the discharge hole. The flow path member includes a plurality of plates stacked in an opening direction of the discharge hole,
The liquid ejection head according to claim 2, wherein the partition is configured by one of the plurality of plates. 4. The liquid ejection head according to claim 3, wherein, in the plate constituting the partition, a thickness of the partition is smaller than a thickness of at least a part of another region. 5. A plurality of said plate, said the plate constituting the partitioning portion, and a plate which overlaps the plate is a liquid of claim 4 which is bonded by Oite adhesive realm of the portion Discharge head. The liquid ejection head according to any one of claims 1 to 5, wherein the first section and the second section are communicated with each other. The partition is located in a range in which a plurality of the first flow paths and a plurality of the second flow paths are connected to the fourth flow path with respect to the flow direction of the fourth flow path. The liquid ejection head according to claim 1. The liquid discharge head according to any one of claims 1 to 7, wherein the partition is separated from an inlet or an outlet of the fourth flow path in the flow direction of the fourth flow path. The flow path member may be configured such that a plurality of the first flow paths and a plurality of the second flow paths of the fourth flow path have a fourth flow rate higher than a first range connected to the fourth flow path. The end of the road is connected to the end of the fifth flow path with respect to a second range in which a plurality of third flow paths of the fifth flow path are connected to the fifth flow path. Further comprising a connecting path,
The liquid ejection head according to any one of claims 1 to 8, wherein the partition portion is located on the first range side with respect to the connection path. The liquid ejection head according to any one of claims 1 to 9, wherein a hole communicating with the first section and the second section is opened in the partition section. The partition has an opening communicating with the first section and the second section,
The liquid ejection head according to claim 9, wherein all or a part of the hole is located in the first range. A liquid discharge head according to claim 1,
A transport unit that transports a recording medium to the liquid ejection head,
A control unit for controlling the liquid ejection head,
A recording device comprising:

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