JP4862101B2 - Inkjet recording head - Google Patents

Description

  The present invention relates to an ink jet recording head that performs recording by ejecting ink onto a recording medium such as paper or cloth.

  Printing apparatuses such as printers, copiers, and facsimiles are configured to record an image composed of a dot pattern on a recording material based on image information. The printing device can be divided into an ink jet method, a wire dot method, a thermal method, a laser beam method, and the like according to the printing method, and the ink jet method includes an ink jet head, and the head ejects ink into a liquid path. Energy conversion means for generating the discharge energy used for the ink, and the ink is led from the ink supply port to the liquid path through the liquid chamber, and the ink is ejected to the ink by the discharge energy given from the energy conversion means. The liquid droplets are made to fly toward the recording material and are recorded by landing. In particular, ink jet heads that eject ink using thermal energy can arrange ink ejection ports for ejecting recording ink droplets to form flying droplets in high density and overall. It has been put to practical use because it has the advantage of being easily compact. In recent years, the number of nozzles arranged in an inkjet head has been increased due to the demand for high-speed recording.

Japanese Patent Laid-Open No. 6-210872

  However, in the ink jet system, in order to handle ink which is a fluid, the meniscus vibration in the discharge nozzle is greatly disturbed by the ink vibration, and the image quality may be deteriorated. In particular, in an inkjet head with a multi-nozzle arrangement with high density, the amount of ink movement per unit time is large, so the inertial force that moves to the front (head side) of the ink in the tank system when ejection is stopped increases. As a result, a positive pressure is applied to the nozzle by this inertial force, and the meniscus protrudes. At this time, when the next print signal is input, small ink droplets are scattered, so-called splash-like printing is performed.

  FIG. 12 is a diagram showing a pressure oscillation waveform in the ink flow path with respect to the ejection pulse when predetermined ejection is performed by the inkjet head, and FIG. 13 is a section A (before ejection start) and a section B (ejection) in FIG. FIG. 6 is a nozzle cross-sectional view showing a state of a meniscus in a C section (immediately after stopping discharge) during operation. As shown in FIG. 12, the pressure vibration amplitude a in the flow channel after stopping the discharge is large, and the flow channel internal pressure becomes a positive pressure, and this vibration disturbs the meniscus vibration at the next discharge. Specifically, a stable meniscus M is formed in period A in FIG. 12 as shown in FIG. 13A, and discharge operation (pulse driving of the heating element 53) is performed in period B in this state. As a result, a good droplet 50 is generated as shown in FIG. Then, in the period C immediately after the discharge is stopped, the pressure in the flow path 52 becomes a large positive pressure due to the inertia of the liquid movement toward the discharge port 51, and as shown in FIG. The meniscus M is formed in a raised state, or in the worst case, ink drops from the ejection port 51. Therefore, as described above, when the next ejection is started in the state of FIG. 13C, small ink droplets are scattered and image formation cannot be performed satisfactorily.

  As a method for solving such a phenomenon, the meniscus vibration is also suppressed by adjusting the flow resistance by changing the filter diameter or the ink flow path. However, if the flow resistance is set high, the ink supply (refill) to the discharge nozzle will not be in time, and a sufficient discharge amount will not be obtained during discharge, resulting in insufficient density. Conversely, the vibration amplitude cannot be suppressed, and the design range is considerably limited. As yet another method, there is a method in which a buffer chamber is provided in the common liquid chamber and bubbles are provided to absorb pressure vibration (see Japanese Patent Application Laid-Open No. 6-210872).

  This is perfect as a means for suppressing pressure vibration, but since the buffer is provided in the common liquid chamber, there is almost no freedom in the buffer volume and shape. In addition, since there are bubbles in the vicinity of the nozzle, there is a high risk of ink non-ejection due to bubble growth.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an ink jet recording head that suppresses ink ejection instability due to ink vibration accompanying ink ejection.

One embodiment of the present invention includes a recording port including a supply port to which ink is supplied, a liquid chamber that holds ink supplied from the supply port, and a discharge port that discharges ink supplied from the liquid chamber. A head unit;
The recording head unit receives ink stored in the ink tank provided at a position different from the supply port in a horizontal direction in the usage state of the recording head unit, and a mounting portion in which an ink tank for storing ink is mounted. A tank holder unit having an outlet for supplying to
In an inkjet recording head having
An ink supply path for flowing ink supplied from the outlet port to the supply port , and a buffer unit connected to the ink supply path and holding gas are formed on the joint surface with the tank holder unit together with the tank holder unit . It has the supply path formation member, It is characterized by the above-mentioned.

  According to the present invention, it is possible to suppress a pressure vibration in a flow path due to ink vibration of ink discharge, maintain a stable discharge state, and always obtain a high-quality image.

1 is a schematic diagram illustrating a first embodiment of an inkjet recording head of the present invention. FIG. 2 is a schematic diagram illustrating an example of the ink jet recording head illustrated in FIG. 1 as viewed from the discharge port side. FIG. 3 is a schematic cross-sectional view showing an example of the ink jet recording head shown in FIGS. 1 and 2. FIG. 3 is an enlarged view of the buffer chamber shown in FIGS. 1 and 2. It is a figure which shows the relationship between the buffer volume and the pressure in a flow path in the inkjet recording head which has a buffer chamber by this invention. FIG. 4 is a pressure vibration waveform diagram in a flow path of the ink jet recording head of the present invention. FIG. 6 is an enlarged view around a buffer chamber according to a second embodiment of the inkjet recording head of the present invention. FIG. 6 is an enlarged view around a buffer chamber according to a third embodiment of the inkjet recording head of the present invention. It is an enlarged view of the buffer chamber by 4th Embodiment of the inkjet recording head of this invention. It is a typical sectional view of a 5th embodiment of an ink jet recording head of the present invention. It is the schematic which shows the flow-path formation member which provided the buffer chamber in the inkjet recording head shown in FIG. It is the figure which showed the pressure oscillation waveform in the ink flow path with respect to the discharge pulse when predetermined discharge is performed with the conventional inkjet head. FIG. 13 is a nozzle cross-sectional view illustrating a state of a meniscus in an A section (before discharge start), a B section (during discharge operation), and a C section (immediately after discharge stop) in FIG. 12.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1 and 2 are exploded perspective views schematically showing a recording head cartridge which is a first embodiment of an ink jet recording head of the present invention. In particular, FIG. 1 is a view as seen from the tank mounting side of the cartridge. FIG. 2 is a view of the discharge port side of the cartridge.

  The head cartridge 1 shown in FIGS. 1 and 2 includes a recording head having two ink ejection portions 19 for three colors of cyan (C), magenta (M), and yellow (Y) and black (Bk). A unit 5 is mounted, and four independent (C, M, Y, Bk) ink tanks 7a, 7b, 7c, and 7d, and a tank holder unit 4 including a mounting portion to which the tanks 7a to 7d are mounted. And a flow path forming member 1 for forming an ink supply path for connecting the ink tanks 7a to 7d for the respective colors and the ink discharge portions 19 for the respective colors.

  The ink supply path grooves 2A and 2B and the buffer chamber grooves 3A and 3B communicating with the ink supply path grooves 2A and 2B are engraved on the joint surfaces of the flow path forming member 1 and the tank holder unit 4, respectively. When the holder unit 4 is joined, the ink supply path grooves 2A and 2B form a tubular ink supply path, and the buffer chamber grooves 3A and 3B form a buffer chamber (buffer section). The buffer chamber is a chamber (space portion) that is provided in a branched manner in the ink supply path in order to absorb ink vibrations, and in which gas exists. The ink supply path groove 2B provided on the joint surface of the flow path forming member 1 of the tank holder unit 4 is accommodated in the ink tank of each color (C, M, Y, Bk) mounted on the tank holder unit 4. A liquid outlet (C) 4a, a liquid outlet (M) 4b, a liquid outlet (Y) 4c, and a liquid outlet (Bk) 4d are formed for leading the discharged ink.

  The flow path forming member 1 and the tank holder unit 4 need to be bonded so that the periphery of the ink supply path and the buffer chamber do not leak. In this embodiment, the ink supply path side groove 2A of the flow path forming member 1 and Welding ribs (see FIG. 4) were provided along the buffer chamber side groove 3A, and bonding was performed by ultrasonic welding. As a result, the gas permeability to the ink supply path and the buffer chamber can be suppressed as compared with the case where sealing around the ink supply path and the buffer chamber is performed with a silicon sealant or the like, and bubbles are generated in the ink supply path due to gas growth. It is possible to prevent non-ejection from occurring due to mixing. Actually, in the 72 hr standing test under the environment of 35 ° C./dry according to the present embodiment, no growth of gas blocking the ink supply path was observed.

  In addition, a liquid supply port is formed in each of the flow path forming member 1 and the recording head unit 5. The liquid supply port of the recording head unit 5 is a liquid supply port (C) 6a connected to an independent common liquid chamber (not shown) of each color in the ink discharge section for discharging three colors (C / M / Y), a liquid supply port (M) 6b, a liquid supply port (Y) 6c, and a liquid supply port (Bk) 6d connected to a common liquid chamber in the ink discharge unit that discharges black (Bk). On the other hand, the liquid supply ports of the flow path forming member 1 are the liquid supply ports (C) 1a, the liquid supply ports (M) 1b, and the liquid supply ports (Y) corresponding to the liquid supply ports 6a to 6d of the recording head unit 5, respectively. 1c and a liquid supply port (Bk) 1d.

  In a state where the tank holder unit 4, the flow path forming member 1, and the recording head unit 5 are joined, the cyan ink in the C tank 7 a is the liquid outlet (C) 4 a of the tank holder unit 4 and the liquid in the flow path forming member 1. The supply port (C) 1a, the ink supply path for C, and the liquid supply port (C) 6a of the recording head unit 5 can be supplied to the C common liquid chamber in the ink discharge section for three colors. Similarly, for the other tanks 7b to 7d, an ink supply path that is independent for each color is formed from a predetermined tank to a common liquid chamber of a discharge unit that discharges ink in the tank.

  1 and FIG. 2 show a state in which the buffer chamber is branched and connected only to the ink supply path communicating with the liquid outlet 4d for black ink in order to simplify the drawings. Buffer chambers are also formed in the ink supply paths for the M and Y ink colors.

  FIG. 3 is a schematic cross-sectional view showing an example of an ink supply path formed in an ink supply system and a recording head unit including a tank, a tank holder unit, and a flow path forming member applicable to the present invention. The ink is supplied from the tank 7 through the filter 11 to the common liquid chamber 10 through the ink supply path 9. 3 is not a cross-sectional view when the components shown in FIGS. 1 and 2 are joined, but schematically shows an ink supply path from the tank to the common liquid chamber formed by the configuration of the present invention. Only. Reference numeral 20 indicates a heater board on which a heating resistance element (ejection heater) 16 as an ejection energy generating element is formed on a substrate using a semiconductor process. The ink supplied to the common liquid chamber 10 passes through the ink flow path 21 provided corresponding to the heater 16, and is discharged from the discharge port by the pressure wave of bubbles generated by film boiling by the heating resistance element 16.

  Further, in the present embodiment, as shown in FIG. 3, a recording apparatus is employed that records an image on the recording paper P by ejecting ink droplets in a substantially gravitational direction from the recording head unit 5 located above the recording paper P. The ink supply path 9 formed by joining the flow path forming member 1 to the tank holder unit 4 and the communication flow path communicating from the ink supply path 9 to the buffer chamber are in a direction (horizontal direction) orthogonal to the direction of gravity. It is provided to become. Thereby, suppression of ink vibration by the buffer chamber can be achieved without considering the influence of the gravity component. However, in the embodiment shown in FIG. 3, an apparatus for performing recording by ejecting ink droplets from the recording head unit 5 in a substantially gravitational direction is shown. However, the present invention provides at least a buffer chamber and an ink supply path 9 communicating with the buffer chamber during recording. As long as the communication flow path is formed in the horizontal direction, the ejection direction of the recording droplets may be in a direction crossing the gravity direction.

  FIG. 4 is an enlarged view of the periphery of the buffer chamber groove 3B communicating with the ink supply channel groove 2B in which the liquid outlet (Bk) 4d in FIG. 2 is formed as an example in order to explain the above-described buffer chamber in more detail. FIG. Referring to this figure, the buffer chamber groove 3B on the joint surface of the flow path forming member 1 of the tank holder unit 4 is formed to communicate with the ink supply path groove 2B by the communication flow path 22. Similarly, as shown in FIG. 1, the buffer chamber groove 3A on the joint surface of the tank holder unit 4 of the flow path forming member 1 is also formed to communicate with the ink supply path groove 2A through the communication flow path 22. ing. Further, each joint surface of the tank holder unit 4 and the flow path forming member 1 is provided with an ink supply path groove, a buffer chamber groove, and a surface portion (welding surface portion) having a welding rib 31 surrounding the communication flow path. ing.

  In the following, as a representative example of FIG. 4, the communication flow path 22 is upstream of the ink flow direction with respect to the ink flow direction (in the direction of the arrow in FIG. 4) at the time of suction recovery by the recording apparatus main body or when the recording head is discharged. It is formed to have an angle of 90 degrees (vertical) or more. Further, the buffer chamber groove 3 </ b> B is configured to be narrowed toward the ink supply path groove 2 </ b> B by the volume expanding portion 23 and the communication flow path 22. More preferably, the cross-sectional area of the communication flow path 22 is smaller than the cross-sectional area of the buffer chamber. With this shape, in the head cartridge completed by joining the flow path forming member and the like, it is possible to prevent the ink from flowing into the buffer chamber when the ink flows in the ink supply path and the gas in the buffer chamber being replaced with the ink. it can. In the present embodiment, when the angle is set to 120 degrees, the gas in the buffer chamber is not replaced with ink during the suction of the main body and the ink discharge.

Further, the absorbability of ink vibration varies greatly depending on the volume of gas present. FIG. 5 is a diagram showing the relationship between the buffer volume and the pressure oscillation amplitude in the flow path generated when the discharge is stopped. The discharge conditions at this time were a discharge nozzle of 304 nozzles, a drive frequency of 18 kHz, and a flow rate of about 9 g / min. As can be seen from this figure, the pressure oscillation amplitude in the flow path decreases as the buffer volume increases. Normally, the pressure in the flow path is in a state where a static negative pressure is applied by the negative pressure generated by the ink tank in the ink stop state (equilibrium state of the meniscus holding force at the nozzle and the negative pressure generated by the ink tank). . The zero point of the pressure in the flow path in FIG. 5 indicates the point where the flow path is the boundary between the static negative pressure region and the positive pressure state. When the inside of the flow path is in a positive pressure state, the meniscus of the nozzle protrudes, and if a print signal is input at this time, the print quality is disturbed. In this embodiment, good printing results could be obtained when the buffer chamber volume was 6 mm ³ or more. However, it may be less depending on the difference in specifications such as the number of ejection nozzles of the head and the driving frequency. In this embodiment, the flow path forming member 1 is provided with a buffer chamber, so that the volume can be increased, and the shape can be freely formed without worrying about undercut at the time of molding. .

  Further, since the buffer chamber is separated from the heater board as a heat source, the gas in the buffer chamber is not affected by the heat generated by driving the heating resistor element. Therefore, the desired performance can be maintained even when the amount of heat is large and the amount of gas in the buffer chamber is large, such as a long head.

FIG. 6 is a schematic diagram showing a pressure oscillation waveform in the flow path when the buffer chamber volume is 12 mm ³ in this embodiment. It can be seen that the pressure vibration amplitude after the printing is stopped is suppressed compared to the case of the conventional head (see FIG. 12).

The gas in the buffer chamber dissolves in the ink, particularly in a low temperature environment. As a result, if the gas in the buffer chamber disappears and is completely replaced with ink, the ink vibration is not absorbed and the meniscus vibration is greatly disturbed. When calculated from the solubility of air in water, the amount of dissolution in this embodiment is 3.4 mm ³ in an environment of 0 ° C. and 1 atm, and the gas in the buffer chamber does not disappear. Actually, the gas in the buffer chamber did not disappear during storage at 5 ° C. for 360 hours, and good print quality could be obtained even after storage. Further, it is possible to enhance the gas retention guarantee in the buffer chamber by imparting water repellency to the inner wall of the buffer chamber by water repellent treatment.

  Next, an example of a form different from the first embodiment described above will be given and only different points will be described.

(Second Embodiment)
FIG. 7 is an enlarged view showing the configuration around the buffer chamber according to the second embodiment of the present invention, and only the points different from the first embodiment will be described here. In particular, FIG. 7 shows a modification of the buffer chamber groove 3B shown in FIG. That is, the buffer chamber formed by joining the tank holder unit 4 and the flow path forming member 1 has at least two volume expansion portions 23 and 24, and the communication flow path 22 is narrower than the volume expansion portion. And 25. In addition to the configuration of FIG. 4, the welding rib 31 is also formed around the volume expanding portion 23 and the communication channel 25. More preferably, the cross-sectional areas of the communication flow paths 22 and 25 are smaller than the cross-sectional areas of the volume expanding portions 23 and 24 serving as buffer chambers. With this configuration, the ink is prevented from flowing into the buffer chamber 23 due to irregular pressure reduction or vibration during transportation of the completed head cartridge, and the gas in the buffer chamber disappearing due to the influence of pressure loss in the communication flow paths 22 and 25. It becomes possible.

(Third embodiment)
FIG. 8 is an enlarged view showing the configuration around the buffer chamber according to the third embodiment of the present invention. Here, only differences from the first embodiment will be described.

  As described with reference to FIG. 4 in the first embodiment, welding is performed so as to surround the ink supply channel groove, the buffer chamber groove, and the communication channel on each joint surface of the tank holder unit and the channel forming member. By providing the surface portion (welding surface portion) having the ribs 31, the inside and outside of the ink supply path and the buffer chamber formed by the welding joining are surely cut off. In addition, in this embodiment, the position of the welding rib 31 at the connection portion between the ink supply channel melt groove 2B and the communication channel 22 branched to the ink supply channel melt groove 2B is indicated by a circled portion A in FIG. The ink supply path melt groove 2 </ b> B and the communication flow path 22 are closer to each other than in the first embodiment, and the weld surface inside the weld rib 31 is narrowed.

  According to this embodiment, regardless of the posture of the completed head cartridge during transportation or storage, ink flows into the buffer chamber 23 through the welding surface inside the welding rib 31 due to irregular vibration, impact, etc. It is possible to prevent the gas in the buffer chamber from disappearing. Further, if the configuration such as part A in FIG. 8 is applied to the second embodiment described above, the gas retention guarantee in the buffer chamber can be further enhanced.

(Fourth embodiment)
FIG. 9 is an enlarged view showing the configuration around the buffer chamber according to the fourth embodiment of the present invention. Here, only differences from the first embodiment will be described.

  The buffer chamber is not limited to one connected to only one side of the ink supply path as shown in FIG. 4, FIG. 7, FIG. 8, and the like, but as represented by FIG. 9, the buffer chamber of the ink supply path groove 2B. A configuration in which a volume expanding portion 26 is provided on the side opposite to the side to which the groove 3B is connected, and the volume expanding portion 26 and the ink supply path groove 2B are connected by a communication channel 27 that is narrower than the volume expanding portion 26. It may be.

  According to this embodiment, regardless of the posture of the completed head cartridge during transportation or storage, ink flows into the buffer chamber due to irregular vibration, impact, etc., and the gas in the buffer chamber disappears. The probability of occurrence is kept low.

  Of course, a configuration in which one buffer chamber is formed on each side of the ink supply path as shown in FIG. 9 or a configuration in which a plurality of buffer chambers are formed is combined with either or both of the configurations in FIG. 7 and FIG. You may apply as follows. In this way, the gas retention guarantee in the buffer chamber can be further enhanced. However, at least one of the communication channels connected to the buffer chambers on both sides of the ink supply channel may be formed so as to have an angle of 90 degrees or more with respect to the ink flow direction when the recording head is discharged. The angles of the communication flow paths do not have to be the same in particular, and may be set to an optimal value according to the mounting mode on the apparatus.

(Fifth embodiment)
FIG. 10 is a schematic sectional view showing a fifth embodiment of the ink jet recording head of the present invention. Reference numeral 28 in FIG. 10 indicates another flow path forming member bonded between the flow path forming member 1 and the holder unit 4, and a buffer for allowing gas to exist in the flow path forming member 28. A chamber 29 is provided. FIG. 11 is a schematic perspective view of the flow path forming member 28. The buffer chamber 29 is formed so as to be stripped toward the ink supply path, and has a slight clearance 30 between the buffer chamber 29 and the tank holder unit 4. That is, the cross-sectional area of the clearance 30, which is a communication channel that connects the buffer chamber and the ink supply path, is sufficiently smaller than the cross-sectional area of the buffer chamber 29. In such a configuration, since the ink instantly seals the entire circumference around the clearance portion, gas-liquid exchange is not performed in the buffer chamber 29, and gas can be held in the buffer chamber. At this time, the tank holder unit 4 and the flow path forming member 28 need to be joined so that there is no leakage around the buffer chamber.

  In the present embodiment, the flow path forming member 28 and the tank holder unit 4 are bonded to each other by ultrasonic welding with a welding rib provided on the joint surface around the buffer chamber 29. In this configuration, when it is impossible to provide a buffer chamber for allowing gas to exist in the ink supply path 2 in a plane, it is possible to provide the buffer chamber only by changing the height direction. There is an advantage that the head can be made compact. By appropriately combining such a form with each of the first to fifth embodiments described above, the degree of freedom of providing a buffer chamber in the ink supply path between the recording head unit and the tank holder unit is increased.

  As described above, the present invention has the following effects. In the ink jet recording head in which the liquid supply path from the tank to the discharging unit that discharges the liquid in the tank is formed by joining the recording head unit having the discharging unit and the tank holder unit, and a recording apparatus using the same, By connecting a buffer chamber that allows gas to exist in the liquid supply path, pressure oscillation in the flow path due to ink vibration during ink ejection can be suppressed, and a stable ejection state can be maintained and high-quality images can always be obtained. It becomes.

  Further, by forming the liquid supply path and the buffer chamber by joining the tank holder unit and one or a plurality of supply path forming members, the shape of the liquid supply path and the buffer chamber and the degree of freedom of the arrangement position are increased. Increase.

  In addition, since the liquid supply path is configured to be in a direction orthogonal to the direction of gravity, ink vibration suppression by the buffer chamber can be achieved without considering the influence of the gravity component.

  Further, the flow path connecting the buffer chamber and the liquid supply path is disposed at an angle of 90 degrees or more upstream with respect to the flow direction from the tank toward the discharge section, so that the buffer chamber can be moved when ink flows in the ink supply path. It is possible to prevent the ink from flowing into the gas and replacing the gas in the buffer chamber with the ink. Furthermore, when the cross-sectional area of the flow path connecting the buffer chamber and the liquid supply path is made smaller than the cross-sectional area of the buffer chamber, the disappearance of the gas in the buffer chamber can be more effectively prevented. Also, the gas retention guarantee in the buffer chamber can be enhanced by treating the inner wall of the buffer chamber with water repellent treatment.

1, 28 Flow path forming member 1a Liquid supply port (C)
1b Liquid supply port (M)
1c Liquid supply port (Y)
1d Liquid supply port (Bk)
2A, 2B Ink supply channel groove 3A, 3B Buffer chamber groove 4 Tank holder unit 4a Liquid outlet (C)
4b Liquid outlet (M)
4c Liquid outlet (Y)
4d Liquid outlet (Bk)
5 Recording head unit 6a Liquid supply port (C)
6b Liquid supply port (M)
6c Liquid supply port (Y)
6d Liquid supply port (Bk)
7 Ink tank 7a Ink tank (C)
7b Ink tank (M)
7c Ink tank (Y)
7d Ink tank (Bk)
9 Ink supply path 10 Common liquid chamber 11 Filter 13 Tank joint seal 14 Discharge unit joint seal 15 Base plate 16 Heater 17 Ink droplet 20 Heater board 21 Ink flow path 22, 25, 27 Buffer chamber communication flow path 23, 24, 26 Buffer Chamber volume expansion part 29 Buffer room 30 Clearance 31 Welding rib

Claims (6)

A recording head unit comprising: a supply port to which ink is supplied; a liquid chamber for holding ink supplied from the supply port; and a discharge port for discharging ink supplied from the liquid chamber;
The recording head unit receives ink stored in the ink tank provided at a position different from the supply port in a horizontal direction in the usage state of the recording head unit, and a mounting portion in which an ink tank for storing ink is mounted. A tank holder unit having an outlet for supplying to
In an inkjet recording head having
An ink supply path for flowing ink supplied from the outlet port to the supply port , and a buffer unit connected to the ink supply path and holding gas are formed on the joint surface with the tank holder unit together with the tank holder unit . An ink jet recording head comprising a supply path forming member.   The ink jet recording head according to claim 1, wherein the ink supply path includes an opening for supplying ink supplied from the ink tank to the supply port.   The inkjet according to claim 1, wherein in the use state, the ink supply path and a flow path connecting the ink supply path and the buffer unit are arranged in a horizontal direction. Recording head.   The flow path connecting the ink supply path and the buffer section extends perpendicularly to the ink supply path, or extends toward the upstream side of the ink supply path in the ink flow direction from the vertical. The inkjet recording head according to claim 3, wherein the inkjet recording head is provided.   The cross-sectional area of the flow path, which is perpendicular to the connection direction of the flow path connecting the ink supply path and the buffer section to the ink supply path, is perpendicular to the connection direction of the buffer section to the flow path. The ink jet recording head according to claim 1, wherein the ink jet recording head is smaller than a cross-sectional area of the buffer portion with respect to a different direction.   6. The ink jet recording head according to claim 1, wherein an inner wall of the buffer portion is subjected to a water repellent treatment.

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