JP2017124617A - Liquid discharging substrate, liquid discharge head and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head, which can circulate liquid through pressure chambers corresponding to a plurality of discharge ports respectively even when the ports are arranged with a high density.SOLUTION: In a first flow path layer 22 are formed a plurality of supply flow paths 14 which are communicated with respective one-side parts of a plurality of pressure chambers 13 and a plurality of collecting flow paths 15 which are communicated with the respective other sides of the plurality of pressure chambers 13. In a second flow path layer 23 are formed a common supply flow path 17 which is communicated with the plurality of supply flow paths 14 and a common collecting flow path 18 which is communicated with the plurality of collecting flow paths 15.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a liquid discharge substrate, a liquid discharge head, and a liquid discharge apparatus for discharging various liquids including ink.

  For example, in an inkjet recording head capable of selectively ejecting ink from a plurality of ejection openings, it is required to increase the density of the ejection openings in order to record a high-definition and high-quality image. Furthermore, it is also required to cope with the influence on the high-quality recording caused by the ink thickening due to the evaporation of water in the ink from the ejection port.

  Patent Documents 1 and 2 describe a method of circulating ink through a pressure chamber so as to prevent the thickened ink from staying in the pressure chamber communicating with the ejection port in order to meet such a requirement. In Patent Document 1, a member in which a curved ink flow path is formed by extrusion processing of aluminum is used, and ink is supplied into a pressure chamber corresponding to each of a plurality of ejection openings through the ink flow path in the member. A configuration for forcibly flowing is described. In Patent Document 2, a member in which an ink flow path that is three-dimensionally bent is used, and ink is forced through the ink flow path in the member into a pressure chamber corresponding to each of a plurality of ejection openings. The structure to be flowed through is described.

Japanese Patent No. 4722826 Patent No. 5264000

  However, the ink flow paths in Patent Documents 1 and 2 have a complicated shape, and the ink flow paths are high so that the ink is circulated through the pressure chambers corresponding to the plurality of discharge ports arranged at high density. It is difficult to form in density.

  The present invention relates to a liquid discharge substrate, a liquid discharge head, and a liquid that can circulate a liquid through a pressure chamber corresponding to each of the discharge ports even when a plurality of discharge ports are arranged at high density. A dispensing device is provided.

  A liquid discharge substrate according to the present invention includes a discharge port for discharging a liquid, a discharge energy generating element for generating energy used for discharging the liquid, and a pressure chamber having the discharge energy generating element therein. The liquid discharge substrate includes a first portion and a second portion that are shifted in the thickness direction of the liquid discharge substrate, and the first portion includes the first portion and the second portion. A supply channel that is arranged on one side of the pressure chamber and supplies liquid to the pressure chamber, and a recovery channel that is arranged on the other side of the pressure chamber and collects liquid from the pressure chamber, A liquid discharge substrate, wherein a common supply channel communicating with a plurality of the supply channels and a common recovery channel communicating with the plurality of the recovery channels are formed in the second portion.

  According to the present invention, a plurality of supply channels, a plurality of recovery channels, a first common supply channel, and a first common recovery channel can be formed with high density. Therefore, even when a plurality of discharge ports are arranged at high density, the liquid can be circulated through the pressure chambers corresponding to the discharge ports. As a result, good discharge performance of the liquid from the discharge port can be maintained. For example, when recording an image by ejecting ink from an ejection port, a decrease in the ejection rate of ink due to evaporation of moisture in the ink from the ejection port is suppressed, and a higher definition and higher quality image is recorded. be able to.

FIG. 3 is an exploded perspective view of a liquid discharge substrate according to the first embodiment of the present invention. FIG. 2 is an exploded plan view of the liquid discharge substrate of FIG. 1. FIG. 2 is a plan view of a main part of the liquid discharge substrate of FIG. 1. It is sectional drawing which follows the IV-IV line of FIG. FIG. 2 is a cross-sectional perspective view of a main part of the liquid discharge substrate of FIG. FIG. 2 is an explanatory diagram of a main part of the liquid discharge substrate of FIG. 1. FIG. 2 is an explanatory diagram of a main part of the liquid discharge substrate of FIG. 1. It is explanatory drawing of the meniscus interface of the ink in a discharge outlet. It is explanatory drawing of the positional relationship of a 1st common supply flow path and a 1st common collection | recovery flow path. 6 is a flowchart for explaining a liquid ejection head creation process. It is a disassembled perspective view of the substrate for liquid discharge in the 2nd Embodiment of this invention. FIG. 12 is an exploded plan view of the liquid discharge substrate of FIG. 11. It is a disassembled perspective view of the substrate for liquid discharge in the 3rd Embodiment of this invention. FIG. 14 is an exploded plan view of the liquid discharge substrate of FIG. 13. It is a disassembled perspective view of the substrate for liquid discharge in the 4th Embodiment of this invention. FIG. 16 is an exploded plan view of the liquid discharge substrate of FIG. 15. FIG. 16 is an explanatory diagram of a main part of the liquid discharge substrate of FIG. 15. It is explanatory drawing of the shape of a 1st common supply flow path and a 1st common collection | recovery flow path. It is a disassembled perspective view of the substrate for liquid discharge in the 5th Embodiment of this invention. FIG. 20 is an exploded plan view of the liquid discharge substrate of FIG. 19. It is a disassembled perspective view of the substrate for liquid discharge in the 6th Embodiment of this invention. FIG. 22 is an exploded plan view of the liquid discharge substrate of FIG. 21. It is explanatory drawing of the arrangement | positioning relationship between the flow path for 1st inks, and the flow path for 2nd inks. 1 is a perspective view of a liquid discharge head to which a liquid discharge substrate of the present invention can be applied. It is explanatory drawing of the inkjet recording device which can apply the liquid discharge head of this invention. It is explanatory drawing of the recording device which is the 1st application example of this invention. FIG. 27 is an explanatory diagram of a first circulation form of an ink circulation path applicable to the recording apparatus of FIG. 26. It is explanatory drawing of the 2nd circulation form of the circulation path of the ink applicable to the recording device of FIG. It is explanatory drawing of the amount of ink circulation in the 1st circulation form and the 2nd circulation form. FIG. 27 is a perspective view of the liquid ejection head in FIG. 26. It is an exploded perspective view of a liquid discharge head. It is a figure which shows the surface and the back surface of the 1st, 2nd and 3rd flow path member in a liquid discharge head. It is an expansion perspective view of the channel formed by joining the 1st, 2nd and 3rd channel members. It is sectional drawing which follows the XXXIV-XXXIV line | wire of FIG. It is a perspective view of a discharge module. It is explanatory drawing of a recording element board | substrate. FIG. 37 is a perspective view of the recording element substrate taken along the line XXXVII-XXXVII in FIG. 36. FIG. 4 is an enlarged plan view of adjacent portions in two recording element substrates. It is a perspective view of the liquid discharge head in the 2nd example of application of the present invention. It is an exploded perspective view of a liquid discharge head. It is explanatory drawing of the flow-path member which comprises a liquid discharge head. FIG. 5 is a perspective view for explaining a connection relationship between a recording element substrate and a flow path member in the liquid discharge head. It is sectional drawing which follows the XLIII-XLIII line | wire of FIG. It is explanatory drawing of the discharge module in a liquid discharge head. 2 is a perspective view of a recording element substrate. FIG. It is explanatory drawing of the recording device as a 2nd application example of this invention. It is explanatory drawing of the recording device of this invention. It is explanatory drawing of the 3rd circulation form of the circulation path of ink. It is explanatory drawing of the liquid discharge head of this invention. It is a figure which shows the disassembled perspective view of the liquid discharge head of this invention. It is a schematic explanatory drawing of the flow-path member of this invention. It is explanatory drawing of the recording device of the 3rd example of application of this invention. It is explanatory drawing of the 4th circulation form of the circulation path of ink. It is explanatory drawing of the liquid discharge head in the 3rd application example of this invention. It is explanatory drawing of the liquid discharge head in the 3rd application example of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A liquid discharge substrate, a liquid discharge head, and a liquid discharge device in the following embodiments are an ink discharge substrate (ink jet recording head substrate), an ink jet recording head, and an ink jet recording device for discharging ink as liquid. This is an application example.

  The liquid discharge head and the liquid discharge apparatus of the present invention can be applied to apparatuses such as printers, copiers, facsimile machines having a communication system, word processors having a printer unit, and industrial recording apparatuses combined with various processing apparatuses. Applicable. For example, it can be used for applications such as biochip fabrication and electronic circuit printing. In addition, the embodiments described below are appropriate specific examples of the present invention, and thus various technically preferable limitations are attached. However, the present embodiment is not limited to the embodiments of the present specification and other specific methods as long as the concept of the present invention is met.

(First embodiment)
FIGS. 1 to 10 are explanatory views of a liquid discharge unit 300 according to the first embodiment of the present invention. The liquid discharge unit 300 constitutes an ink jet recording head, and the recording head is an ink jet recording as will be described later. Mounted on the device.

  As shown in FIGS. 1 and 2, the liquid discharge unit 300 of this embodiment includes an orifice plate 21, a first flow path layer 22, a second flow path layer 23, a third flow path layer 24, and a fourth flow path layer 25. The fifth flow path layer 26 and the sixth flow path layer 27 have six laminated flow path configurations. The first flow path layer 22 includes a discharge energy generating element 12 that generates discharge energy for discharging ink as a liquid, and the ink in the pressure chamber 13 is transferred to the orifice plate 21 by the discharge energy. It is possible to discharge from the discharge port 11. When the ink in the pressure chamber 13 is in a static state, the pressure in the pressure chamber 13 is kept at such a negative pressure that an ink meniscus is formed at the ejection port 11. When the pressure in the pressure chamber 13 varies, the ink ejection speed, the ejection amount (volume), and the like change to affect the ink ejection characteristics. In particular, when the pressure chamber 13 is lower than a predetermined pressure, it becomes difficult to eject ink.

  As the discharge energy generating element 12, an electrothermal conversion element (heater), a piezoelectric element, or the like can be used. When the heater is used, the ink in the pressure chamber 13 is foamed by the heat generation, and the ink can be ejected from the ejection port 11 using the foaming energy.

  As shown in FIG. 3, a plurality of discharge ports 11 are arranged at high density so as to form a discharge port array 16. In this example, four discharge port arrays 16 are formed. As shown in FIG. 4, the first common supply channel 17 of the second channel layer 23 is connected to one of the pressure chambers 13 via the individual supply channel 14 and the channel 10 corresponding to each pressure chamber 13. It communicates with the side (left side in FIG. 4). Similarly, the first common recovery channel 18 of the second channel layer 23 passes from the pressure chamber 13 through the channel 10 and the individual recovery channel 15 to the other side of each pressure chamber 13 (the right side in FIG. 4). ). The plurality of supply channels 14 and the plurality of recovery channels 15 each extend in the thickness direction of the first channel layer 22 and are arranged along the extending direction (first direction) of the discharge port array 16. As a result, a supply flow path array and a recovery flow path array are formed. The thickness direction of the first flow path layer 22 corresponds to a direction that intersects (or orthogonally intersects in this example) with the surface of the liquid ejection substrate on which the ejection energy generating elements 12 are disposed. The first common supply channel 17 communicates with a first supply port 30 formed in the third channel layer 24 and receives ink supplied from the first supply port 30. Similarly, the first common recovery channel 18 communicates with the first recovery port 31 formed in the third channel layer 24. A plurality of first supply ports 30 are arranged along the extending direction (first direction) of the discharge port array 16 to form a first supply port array. Similarly, a plurality of first recovery ports 31 are arranged in a direction along the first supply port row, forming a first recovery port row. In the third flow path layer 24, four first supply port rows and four first recovery port rows are alternately formed in parallel. A second common supply channel 32 and a second common recovery channel 33 are formed in the fourth channel layer 25, and a second supply port 34 and a second recovery port 35 are formed in the fifth channel layer 26. Is formed. In the sixth flow path layer 27, a third common supply flow path 36 and a third common recovery flow path 37 are formed.

  In the first common supply channel 17, one side in the thickness direction of the second channel layer 23 (side facing the first channel layer 22) communicates with the plurality of supply channels 14, and the other side (third The side facing the flow path layer 24) communicates with the plurality of first supply ports 30. Similarly, in the first common recovery channel 18, one side in the thickness direction of the second channel layer 23 communicates with the plurality of recovery channels 15, and the other side communicates with the plurality of first recovery ports 31. In the second common supply channel 32, one side in the thickness direction of the fourth channel layer 25 communicates with the plurality of first supply ports 30, and the other side communicates with the plurality of second supply ports 34. Similarly, in the second common recovery channel 33, one side in the thickness direction of the fourth channel layer 25 communicates with the first recovery port 31, and the other side communicates with the second recovery port 35. The third common supply channel 36 communicates with the plurality of second supply ports 34, and the third common recovery channel 37 communicates with the plurality of second recovery ports 35.

  The arrangement density of the plurality of second supply ports 34 and the arrangement density of the plurality of second collection ports 35 are lower than the arrangement density of the plurality of first supply ports 30 and the arrangement density of the plurality of first collection ports 31. Further, the arrangement density of the plurality of first supply ports 30 and the arrangement density of the plurality of first recovery ports 31 are lower than the arrangement density of the plurality of supply passages 14 and the arrangement density of the plurality of collection passages 15. The first common supply channel 17 and the first common recovery channel 18 are formed in parallel along the first direction, and the second common supply channel 32 and the second common recovery channel 33 are respectively It is formed in parallel so as to follow the direction of 2. The third common supply channel 36 and the third common recovery channel 37 are formed in parallel along the first direction.

  The liquid discharge unit 300 of this example is configured by stacking a plurality of flow path members in this way. The formation density of the flow paths in these flow path layers is the sixth flow path layer 27, the fifth flow path layer 26, the fourth flow path layer 25, the third flow path layer 24, the second flow path layer 23, and the first flow path layer. The flow path layer 22 increases in order. Accordingly, it is possible to configure the liquid discharge unit 300 including the plurality of discharge port arrays 16 at a high density while suppressing the increase in size of the element substrate and each flow path member.

  The first flow path layer 22 and the second flow path layer 23 are formed on the liquid discharge substrate 100 in the embodiment of FIG. 24 described later. The configuration of the third flow path layer 24 to the sixth flow path layer 27 is not particularly limited in the present invention. Specifically, the following first and second configuration examples can be given. In the first configuration example, the third flow path layer 24 is formed on the cover plate (lid member) 20 or 2020 in the embodiment of FIGS. 36 and 45 described later, and a part of the fourth flow path layer 25 is described later. It forms in the support member 400 in embodiment of FIG. Another part of the fourth flow path layer 25 is formed in the first flow path member 500 or 50 in the embodiment of FIG. 24 or FIG. 31 described later, and the fifth flow path layer 26 and the sixth flow path layer 27 are formed. A part is formed in the second flow path member 600 or 60 in the embodiment of FIG. Another part of the sixth flow path layer 27 is formed in the third flow path member 370 in the embodiment of FIG. On the other hand, in the second configuration example, the third flow path layer 24 is formed on the cover plate 20 or 2020 and a part of the fourth flow path layer 25 is formed on the support member 400. The other part of the fourth flow path layer 25 and the fifth flow path layer 26 are formed in the first flow path member 500 or 50, and the sixth flow path layer 27 is formed in the second flow path member 600 or 60. . The second common supply channel 32, the second common recovery channel 33, the second supply port 34, and the second recovery port 35 are not limited to the configuration of this example.

  The ink supplied from the outside is supplied from the third common supply channel 36 communicating with the ink inflow opening, to the second supply port 34, the second common supply channel 32, the first supply port 30, and the first common supply channel. 17 and the supply flow path 14 are sequentially guided to the pressure chamber 13. The ink in the pressure chamber 13 sequentially passes through the recovery channel 15, the first common recovery channel 18, the first recovery port 31, the second common recovery channel 33, the second recovery port 35, and the third common recovery channel 37. Then, it is recovered from the recovery opening communicating with the third common recovery flow path 37 to the outside. By circulating the ink in this way, the thickened ink that tends to stay in the pressure chamber 13 is collected, and the decrease in the discharge speed of the ink from the discharge port 11 and the change in the color material density in the ink are suppressed. be able to. Hereinafter, such a forced flow of ink is referred to as “ink circulation flow”.

  In this example, the supply channel 14 and the recovery channel 15 are disposed so as to face each other with the discharge port 11 interposed therebetween, as shown in FIGS. By facing the supply flow path 14 and the recovery flow path 15 in this manner, an ink circulation flow passing through the pressure chamber 13 and the discharge port 11 is efficiently generated, and the ink discharge speed is reduced and the ink color is reduced. Changes in the material concentration can be suppressed more efficiently. The supply channel 14 and the recovery channel 15 are divided into a plurality of portions in the first direction in which the discharge port array 16 extends so as to correspond to each of the pressure chambers 13. Thus, by forming the supply flow path 14 and the recovery flow path 15 in a plurality of parts, the ejection energy generating element 12 is provided between the adjacent supply flow paths 14 and between the adjacent recovery flow paths 15. It is possible to provide electrical wiring for driving the motor. Therefore, it is not necessary to provide a wiring extending in the first direction between the supply flow path 14 and the discharge port 11 and between the recovery flow path 15 and the discharge port 11. It becomes possible to make it smaller. The relationship between the number of the supply passages 14 and the discharge ports 11 may be 1: 1, 1: 2, or 1: 5, and the number of pressure chambers 13 with which the supply passages 14 communicate is as in this example. It is not limited to only one.

  In this example, in order to generate an ink circulation flow through the pressure chamber 13 and the discharge port 11, a flow path is formed as follows.

  As shown in FIG. 2, the first common supply channel 17 extends in the first direction and communicates with the plurality of supply channels 14, and further communicates with the pressure chamber 13 via each of the supply channels 14. To do. Similarly, the first common recovery channel 18 extends in the first direction and communicates with the plurality of recovery channels 15, and further communicates with the pressure chamber 13 via each recovery channel 15.

  As described above, the first flow path layer 22 and the second flow path layer 23 include a series of inks including the supply flow path 14, the recovery flow path 15, the first common supply flow path 17, and the first common recovery flow path 18. A flow path is formed in association with the discharge port array 16. Through such an ink flow path, an ink circulation flow can be generated in the pressure chamber 13 of the liquid discharge substrate 100 and in the discharge port 11 of the orifice plate 21.

  Further, as shown in FIG. 6A, the side walls forming the supply flow path 14, the recovery flow path 15, the first common supply flow path 17, and the first common recovery flow path 18 are respectively the first flow path layer 22. Are substantially orthogonal to the front and back surfaces (upper and lower surfaces in the figure). Here, the term “substantially orthogonal” includes an inclination such as a taper shape generated when the first flow path layer 22 and the second flow path layer 23 are processed. The supply channel 14, the recovery channel 15, the first common supply channel 17, and the first common recovery channel 18 are formed by, for example, dry etching. Further, they may be formed by laser processing, or dry etching processing and laser processing may be combined. The depth direction (vertical direction in FIG. 6A) of the supply flow path 14, the recovery flow path 15, the first common supply flow path 17, and the first common recovery flow path 18 is the first flow path layer 22. It is substantially perpendicular to the surface. Thereby, these ink flow paths are efficiently formed in high density, and the ink circulation flow is generated more efficiently in the pressure chambers 13 and the discharge ports 11 formed in the first flow path layer 22 with high density. be able to.

(Relationship (1) between first common supply channel 17 and first common recovery channel 18)
The first common supply channel 17 and the first common recovery channel 18 are formed as follows.

As shown in FIGS. 6A and 6B, the interval (beam width) between the downstream end of the first common supply channel 17 and the upstream end of the second common recovery channel 18 is W1, The distance between the supply channel 14 and the recovery channel 15 is W2. Further, the channel resistance per unit length from the downstream end of the supply channel 14 to the upstream end of the recovery channel 15 through the channel 10, the pressure chamber 13, and the channel 10. Is R, and the flow rate of the ink circulation flow generated in each pressure chamber 13 is Q1. The flow path resistance R is expressed by an expression including a term (including a time element) representing the viscosity of the ink. Further, the maximum negative pressure in the range where the ink meniscus interface does not collapse at the discharge port 11 or the maximum negative pressure in the pressure chamber 13 in the range where ink can be properly discharged from the discharge port 11 is defined as Pmax. These are in the relationship of the following formula (1). This relational expression (1) will be described later.
W2 <(2 × Pmax) / (Q1 × R) (1)

  When the meniscus interface sinks due to the negative pressure as shown in FIG. 8A and the negative pressure increases and the meniscus interface on the surface of the discharge port 11 collapses as shown in FIG. 8B. The ink almost does not exist on the ejection energy generating element 12, and normal ejection becomes difficult. When the surface tension of the ink is 30 mN / m and 20 mN / m, the diameter of the discharge port 11 and the limit of the allowable pressure at the discharge port 11 are in a relationship as shown in FIG. In general, the meniscus of the ink at the ejection port depends on the diameter of the ejection port and the surface tension of the ink, but the meniscus interface collapses unless a pressure of −1000 mmAq or more is maintained. Therefore, the maximum negative pressure within a range where the meniscus interface does not collapse is, for example, −1000 mmAq when the diameter of the ejection port is 12 μm and the surface tension of the ink is 30 mN / m. Even in the range where the meniscus interface does not collapse, as shown in FIG. 8 (a), the amount of ejected ink is reduced due to the sedimentation of the meniscus interface, and the ink ejection state is affected and the sub-drop of the ink (satellite) ) Will occur.

  Here, the proper discharge of ink is a good discharge state of ink to the extent that no disturbance of the recorded image is visually confirmed. In particular, a discharge state that is so small that the change amount of the discharged ink amount cannot be visually confirmed is preferable. In addition, when ink main droplets and sub-droplets (satellite) are generated when ink is ejected, at least one of the ink sub-dots formed by the satellite is added to the main todd of the ink formed by the main droplet landing on the recording medium. An ink discharge state in which part of the ink contacts is preferable.

  Thus, the maximum negative pressure Pmax is a negative pressure at which the meniscus interface collapses or ink cannot be ejected properly when the negative pressure becomes higher than that. Further, when sub-dots are generated, it is preferable that the satellites land on the recording medium so that the sub-dots are located within the main dots. For example, the maximum negative pressure Pmax was 500 mmAq. The ink circulation flow rate Q1 is a flow rate capable of suppressing a decrease in ink ejection speed and a change in ink color material density. In other words, the flow rate is such that the ink ejection speed is reduced by the influence of evaporation of moisture in the ink from the ejection port 11 and the deviation of the landing position of the ink that can be recognized is suppressed. Further, the flow rate can also suppress the occurrence of color unevenness in the recorded image that can be visually observed due to the change in the colorant concentration of the ink due to the influence of evaporation of moisture in the ink from the ejection port 11. For example, the ink circulation flow rate Q1 is a circulation flow rate that suppresses the decrease in the ink discharge speed to within 10% of the normal discharge time. In the experimental example, 0.05 m / s in terms of the flow rate in the pressure chamber 13 That was all. In other experimental examples, the flow velocity was 0.1 m / s.

  By satisfying the relationship of the above equation (1), the pressure in the first common supply flow path 17 can be maintained at a negative pressure. In an ink jet recording head, the pressure in the flow path of the recording head should be a negative pressure, and when it is set to a positive pressure, the following conditions are likely to occur. That is, when the pressure in the ink flow path of the recording head is positive, the ink tends to leak from the constituent members of the recording head. Further, ink leakage from the ejection port 11 is likely to occur. For example, even if the pressure in the first common supply flow path 17 is positive and the pressure chamber 13 is maintained at a negative pressure due to pressure loss due to the ink circulation flow, the ink circulation flow may cause a change. There is a possibility that the pressure loss fluctuates and the pressure chamber 13 becomes a positive pressure. As an extreme example, when the ink circulation flow is stopped, the pressure of the pressure chamber 13 may be the same positive pressure as that of the first common supply flow path. In order to prevent the pressure chamber 13 from becoming a positive pressure, complicated control of the ink supply system is required.

(Explanation about relational expression (1))
Next, the above formula (1) for keeping the pressure of the first common supply flow path 17 at a negative pressure will be described in detail.

The differential pressure ΔP between the supply channel 14 and the recovery channel 15 is expressed by the following equation (2).
ΔP = Q1 × R × W2 (2)

Further, when the pressure of the supply flow path 14 is Pin and the pressure of the recovery flow path 15 is Pout, the following expression (3) is established, and the discharge port 11 is connected to the supply flow path 14 and the recovery flow path 15. Is located in the middle, the pressure Pn of the discharge port 11 is expressed by the following equation (4).
ΔP = Pin−Pout (3)
Pn = (Pin + Pout) / 2 (4)

  From the above equations (3) and (4), the following equation (5) is established.

  Pin = Pn + (ΔP / 2) (5)

  In order to make the pressure of the first common supply flow path 17 negative, it is necessary to satisfy the following expression (6).

  Pin = Pn + (ΔP / 2) <0 (6)

The above equation (6) can be transformed into the following equation (7).
-Pn> ΔP / 2 (7)

In order to eject ink normally, it is necessary that Pn> −PMAX, so the following equation (8) is established.
Pmax> ΔP / 2 (8)

  The above equation (1) can be derived from the above equations (2) and (8).

W1 and W2 have the relationship of the following formula (9).
W1 <W2 (9)

From the relationship of the above equation (9), the following equation (10) is established.
W1 <(2 × Pmax) / (Q1 × R) (10)

  By setting the interval W1 so as to satisfy the relationship of the above formula (10), the pressure of the first common supply flow path 17 can be kept negative, and the reliability of the substrate H and the recording head is improved. Can do.

  In particular, in a recording head having a high flow path resistance in the pressure chamber 13, it is necessary to make the interval (beam width) W1 smaller. In a recording head using a piezoelectric element as the ejection energy generating element 12, the interval W1 may be increased because the flow path resistance of the pressure chamber 13 is usually small. On the other hand, in a recording head that uses a heater as the ejection energy generating element 12, the flow path resistance of the pressure chamber 13 is usually large, so the interval W1 needs to be made smaller.

(Relationship between first common supply channel 17 and first common recovery channel 18 (2))
When the maximum ejection amount of ink ejected from the ejection port 11 is Q2, the first common supply channel 17 and the first common recovery channel 18 may be set so as to satisfy the relationship of the following equation (11). desirable.
W1 <(2 × Pmax) / (Q2 × R) (11)

  By making the ink circulation flow rate Q1 larger than the maximum ejection amount Q2, it is possible to suppress the reverse flow of the ink circulation flow even during the maximum ink ejection. If a reverse flow of the ink circulation flow occurs, for example, the heat generated during ink ejection may not be exhausted due to the ink circulation flow, and the ink may be overheated due to the reverse flow of the exhaust heat. There is a possibility that ink ejection failure may be caused by the backflow of dust in the path. By suppressing the reverse flow of the ink circulation flow, it is possible to suppress the occurrence of such a state.

  By setting the first common supply flow path 17 and the first common recovery flow path 18 so as to satisfy the relationship of Expression (11), the reverse flow of the ink circulation flow is suppressed, and the first common supply flow path 17 It is possible to maintain the negative pressure at a negative pressure. As a result, the reliability of the substrate H and the recording head can be improved.

  As a result of the experiment, by setting the height of the pressure chamber 13 to 20 μm, the viscosity of the ink to 10 cP, and the beam width W1 to 200 μm or less, the ink circulation flow rate is 0.1 m necessary for suppressing the backflow of the ink circulation flow. Even in the case of / s, the inside of the first common supply channel 17 could be kept at a negative pressure. In addition, by setting the beam width W to 100 μm or less, the first common can be achieved while suppressing the back flow of the ink circulation flow even when the ink having the volume of 10 pl is ejected at the ejection frequency of 30 kHz (the driving frequency of the recording head). The pressure in the supply flow path 17 could be kept negative.

(Disposition relation of the flow paths 17, 14 and arrangement relation of the flow paths 18, 15)
Furthermore, the arrangement relationship between the first common supply channel 17 and the supply channel 14 and the arrangement relationship between the first common collection channel 18 and the collection channel 15 may be set as follows. That is, as shown in FIG. 6B, the center L1 of the supply channel 14 in the second direction is set at a position closer to the discharge port 11 than the center L2 of the first common supply channel 17 in the second direction. To do. Similarly, the center L3 of the recovery channel 15 in the second direction is set at a position closer to the discharge port 11 than the center L4 of the first common recovery channel 18 in the second direction. In this way, by bringing the supply flow path 14 and the recovery flow path 15 closer to the discharge port 11, the width W 2 can be made smaller even when the same beam width W 1 is set, so that the inside of the discharge port 11 has an appropriate pressure. It is easy to keep.

(Disposition relation of the flow path 17 and the flow path 18)
The arrangement relationship between the first common supply channel 17 and the first common recovery channel 18 is preferably set as follows.

  That is, when the beam width between the first common supply channel 17 and the first common recovery channel 18 located between the adjacent discharge port arrays 16 is W3 as shown in FIG. 9, the beam width W3 is It is set larger than the beam width W1. By increasing the beam width W3, the strength of the substrate can be increased. FIG. 9 is a view of the liquid discharge substrate as seen from the back side so that the discharge port 11 can be seen through. In this way, the first common supply flow path 17 and the first common recovery flow path 18 communicating with the same discharge port array 16 are brought closer to each other so as to reduce the beam width W1. On the other hand, the first common supply channel 17 that communicates with one of the adjacent discharge port arrays 16 and the first common recovery channel 18 that communicates with the other side are separated so as to increase the beam width W2. As a result, it is possible to suppress the reverse flow of the ink circulation flow and increase the strength of the substrate while keeping the pressure in the first common supply flow path 17 at a negative pressure.

(Ink circulation flow rate and pressure variation suppressing structure (1))
Furthermore, in this embodiment, the following structure is provided in order to suppress variations in ink circulation flow rate and pressure in each pressure chamber 13.

  That is, as shown in FIGS. 1 and 2, a plurality of first supply ports 30 communicate with one first common supply channel 17, and similarly, a plurality of first common recovery channels 18 have a plurality. The first recovery port 31 is in communication. The first supply port 30 and the first recovery port 31 are arranged so that the ink circulation flow rate and the pressure variation in each pressure chamber 13 are within a range that does not significantly affect the ink ejection characteristics. . Specifically, the first supply port 30 and the first recovery port 31 are arranged alternately in the first direction in which the discharge port array 16 extends. Thereby, the space | interval of the 1st supply port 30 and the 1st collection | recovery port 31 in a 1st direction can be made narrower. Therefore, even when the channel widths of the first common supply channel 17 and the first common recovery channel 18 are relatively narrow, variations in the ink circulation flow rate and pressure in each pressure chamber 13 can be suppressed.

(Ink circulation flow rate and pressure variation suppression structure (2))
Furthermore, in this embodiment, the following structure is provided in order to suppress variations in ink circulation flow rate and pressure in each pressure chamber 13.

  That is, as shown in FIGS. 1 and 2, the second common supply flow path 32 extends in the second direction and communicates with a plurality of first supply ports 30 arranged in the second direction. . Similarly, the second common recovery flow path 33 extends in the second direction and communicates with the plurality of first recovery ports 31 arranged in the second direction. Further, the plurality of second common supply channels 32 are collectively connected to one third common supply channel 36 via the second supply port 34. Similarly, the plurality of second common recovery channels 33 are collectively connected to one third common recovery channel 37 via the second recovery port 35.

  As described above, the plurality of first common supply channels 17 formed at a narrow pitch in accordance with the plurality of discharge port arrays 16 arranged at high density by connecting the ink channels with a six-layer structure include a plurality of first common supply channels 17. The third common supply flow path 36 is finally collected through the first supply port 30. Similarly, the plurality of first common recovery flow paths 18 formed at a narrow pitch in accordance with the plurality of discharge port arrays 16 arranged at a high density are finally passed through the plurality of first recovery ports. The third common recovery channel 37 is collected. Therefore, the plurality of discharge port arrays 16 can be arranged with high density without increasing the channel widths of the first common supply channel 17 and the first common recovery channel 18. In addition, in each pressure chamber 13 corresponding to each ejection port 11 of the plurality of ejection port arrays 16 arranged at high density in this way, variations in the ink circulation flow rate and pressure can be suppressed. In addition, the supply of ink from an ink tank (not shown) and the recovery of ink to the ink tank are suppressed while suppressing variations in the ink circulation flow rate and pressure in the pressure chamber 13 with respect to the discharge ports 11 arranged at high density. Can be realized easily. Accordingly, not only the recording head and the recording apparatus including the recording head but also the entire system of various liquid discharging heads and the liquid discharging apparatus including the liquid discharging head can be configured compactly.

(Ink circulation flow rate and pressure variation suppression structure (3))
In order to suppress variations in the ink circulation flow rate and pressure in each pressure chamber 13, it is desirable to have the following structure.

  In other words, the first supply port 30 and / or the first recovery port 31 positioned at both ends of the discharge port array 16 are shaped more than the first supply port 30 and / or the first recovery port 31 positioned other than the both ends. Make it smaller. That is, the opening of the former first supply port 30 and / or the first recovery port 31 is formed smaller than the opening of the latter first supply port 30 / or the first recovery port 31. For the first supply ports 30 located at both ends of the discharge port array 16, the discharge ports 11 of the discharge port array 16 are positioned only on one side thereof, so the first supply located at both ends of the discharge port array 16. The ink flow rate at the port 30 is smaller than the ink flow rates at the other first supply ports 30. Similarly, the first recovery ports 31 located at both ends of the discharge port array 16 are positioned at both ends of the discharge port array 16 because the discharge ports 11 of the discharge port array 16 are positioned only on one side thereof. The ink flow rate at the first recovery port 31 is smaller than the ink flow rates at the other first recovery ports 31.

  Thus, regarding the 1st supply port 30 and / or the 1st recovery port 31 which are located in the both ends of the discharge port row | line | column 16, those shapes are made small and flow path resistance is enlarged. Thereby, the pressure loss generated in the first supply port 30 and / or the first recovery port 31 can be made closer to the pressure loss generated in the other first supply port 30 and / or the first recovery port 31. Therefore, the ink flow rate that flows into the pressure chamber 13 through the first supply port 30 and / or the first recovery port 31 at both ends, and the ink that flows into the pressure chamber 13 through the other first supply port 30 and / or the first recovery port 31. The difference between the flow rate and the flow rate can be reduced. As a result, it is possible to further suppress variations in the ink circulation flow rate in each pressure chamber 13.

(Ink circulation flow rate and pressure variation suppressing structure (4))
In order to suppress variations in the ink circulation flow rate and pressure in each pressure chamber 13, it is desirable to have the following structure.

  That is, as shown in FIG. 7A, a region a between the end of the discharge port array 16 and the end of the liquid discharge substrate 100 is set large. The region a can be used as an arrangement space for the connection pads 150 for transmitting and receiving electrical signals to and from the liquid discharge substrate 100, the drive circuit for the discharge energy generating element 12, and the like. Further, by using such a region a, the first recovery port 31 is provided as shown in the perspective views of FIGS. 7B and 7C when the liquid discharge substrate 100 is viewed from the discharge port 11 side. Is desirable. That is, in the first direction in which the discharge port array 16 extends, the first recovery port 31 is arranged so as to overlap the discharge port 11 located at the end of the discharge port array 16. In FIG. 7B, the left end portion of the first common recovery flow path 18 and the left end portion of the first recovery port 31 are at the same position. Further, in FIG. 7C, the left end portions of the first common recovery flow path 18 and the first recovery port 31 bulge larger to the left than the recovery flow path 15 located at the left end.

  In FIGS. 7B and 7C, the ink passing through the pressure chamber 13 located at the end of the ejection port array 16 is first fed from the first supply port 30 to the first common supply channel 17 as indicated by the arrow A1. And enters the supply channel 14. Thereafter, as indicated by an arrow A2, the pressure is recovered from the first recovery port 31 after passing through the pressure chamber 13, the recovery flow path 15, and the first common recovery flow path 18 located at the end of the discharge port array 16. FIG. 7D is a comparative example in the case where the first recovery port 31 is provided so as not to overlap the discharge port 11 located at the end of the discharge port row 16 in the first direction. In FIG. 7D, the ink passing through the pressure chamber 13 located at the end of the discharge port array 16 is first supplied from the first supply port 30 to the first common supply channel 17 and the supply channel as indicated by the arrow A1. Enter 14. Thereafter, after passing through the pressure chamber 13 and the recovery passage 15 located at the end of the discharge port array 16 as indicated by an arrow A2, the first recovery port passes through the first common recovery passage 18 as indicated by an arrow A3. Collect from 31.

  7 (b) and 7 (c), the first recovery through the pressure chamber 13 from the first supply port 30 located at the end in the first direction, as compared with the configuration of FIG. 7 (d). It is possible to shorten the length of the ink flow path from the opening 31 until the ink is collected. That is, the maximum pressure loss generated in the first common supply channel 17 and the first common recovery channel 18 in the vicinity of the end of the ejection port array 16 is reduced, and variations in the ink circulation flow rate in each pressure chamber 13 are suppressed. can do. When the first supply port 30 is located at the end in the first direction instead of the first recovery port 31, the discharge located at the end of the discharge port array 16 in the first direction is similarly performed. What is necessary is just to arrange | position the 1st supply port 30 so that the exit 11 may overlap.

(Temperature distribution suppression structure)
In the present embodiment, the following structure is provided to suppress the temperature distribution in the recording head.

  That is, as shown in FIGS. 1 and 2, the first recovery ports 31 are located at both ends of the discharge port array 16. When the ink is forcibly circulated through each pressure chamber 13 as in this example, normally, heat generated from the ejection energy generating element 12 or the like is recovered by the ink, so that the ink is more than in each pressure chamber 13. The temperature of the ink in the collection-side flow path becomes high.

  Further, even when a sufficient ink circulation flow rate is secured to suppress the influence of evaporation of moisture in the ink from the ejection ports 11, when ink is ejected simultaneously from a larger number of ejection ports 11 than the ink circulation flow rate. There is a case where the amount of discharge becomes larger. In such a case, ink is also supplied into the pressure chamber 13 from the second common recovery channel 37. That is, from the second common recovery channel 37, through the second recovery port 35, the second common recovery channel 33, the first recovery port 31, the first common recovery channel 18, and the recovery channel 15, the pressure chamber Ink is supplied into the inside 13. For this reason, when ink is simultaneously ejected from a large number of ejection ports 11, high-temperature ink in the first recovery port 31 may be supplied into the pressure chamber 13. In such a case, the temperature of the ink near the first recovery port 31 is higher than the vicinity of the first supply port 30, and the discharge port 11 near the first supply port 30 and the discharge port near the first recovery port 31. 11 may cause a difference in ink ejection speed. Further, when the first supply port 30 is located at one end of the both ends of the discharge port array 16 and the first recovery port 31 is positioned at the other end side, the entire discharge port array 16 is heated in the arrangement direction. An inclination of the distribution occurs, and the heat distribution width of the entire recording head increases. As a result, the ink ejection characteristics at each ejection port 11 may vary.

  In the present embodiment, since the first recovery ports 31 are provided at both ends of the discharge port array 16, it is possible to suppress such a gradient of the heat distribution and to suppress variations in ink discharge characteristics. The same effect can be obtained when the first supply ports 30 are provided at both ends of the discharge port array 16. However, as in the present embodiment, it is desirable to provide the first recovery ports 31 at both ends of the discharge port array 16.

  That is, in the liquid discharge substrate 100, as described above, the region a where the discharge port 11 is not provided is set large between both ends of the discharge port array 16 and the end of the liquid discharge substrate 100. From this region a, heat generated during ink ejection is dissipated. For this reason, when a large number of ejection ports 11 eject ink, the temperatures at both ends of the ejection port array 16 tend to be lower than those at other portions. By providing the first recovery ports 31 at both ends of the discharge port array 16, it is possible to supply ink having a high temperature to both ends of the discharge port array 16 in such a case. Therefore, the temperature at both ends of the discharge port array 16 can be increased, and the temperature difference from the other portions can be reduced. As a result, it is possible to reduce the heat distribution width of the entire recording head and suppress variations in ink ejection characteristics.

  FIG. 10 is a flowchart for explaining an example of a manufacturing process of the liquid discharge head of this embodiment.

  First, nozzles are formed on the liquid ejection substrate 100 on which the ejection energy generating elements 12 and necessary circuits are already formed by the nozzle formation step S1. The nozzle is a portion for ejecting ink using the ejection energy generating element 12, and includes the ejection port 11 and the pressure chamber 13. Thereafter, the first common supply channel 17 and the first common recovery channel 18 are formed on the back surface of the liquid ejection substrate 100 by the back surface supply channel forming step S2. Next, the cover plate 20 (lid member) or 2020 in the embodiment of FIG. 36 or 45 is formed on the back surface of the liquid ejection substrate 100 by the lid member forming step S3. Thereafter, in the cutting step S4, the outer shape of the liquid discharge substrate 100 is processed so that the wafer form is changed to the chip form. Thereafter, the liquid discharge substrate 100 is bonded to the support member 400 and the first flow path member 500 of the embodiment of FIG. 24 in the bonding step S5.

  In this way, the cover member forming step S3 prior to the bonding step S5 forms the cover plate serving as the third flow path layer on the back surface of the liquid discharge substrate 100. One supply port 30 and a first recovery port 31 can be formed. By processing the cover plate when the liquid discharge substrate 100 is in the form of a wafer, the processing accuracy is higher than that of machining or molding, so that finer holes can be formed at a higher density. In addition, the cover plate can be made thinner. Therefore, the discharge ports 11 can be arranged with higher density. In addition, the flow resistance of the first supply port 30 and the first recovery port 31 can be reduced and the variation can be reduced, so that the differential pressure for causing the ink circulation flow can be stabilized. Can be kept small.

  The cover plate may be formed of a silicon substrate. That is, the number of processes can be reduced as compared with the case where a cover plate made of a wafer-type silicon substrate is bonded to the wafer-type liquid discharge substrate 100 and the cover plate is bonded to the chip-type liquid discharge substrate 100. Become. The cover plate may be formed of a resin film. As in the case of the silicon substrate, the cover plate can be bonded by laminating the resin in the film state on the wafer-type liquid discharge substrate 100. Therefore, when the cover plate is bonded to each chip-type liquid discharge substrate 100 This makes it possible to reduce the number of processes.

  The process order and process contents in FIG. 10 are examples, and do not limit the present invention. For example, the order of the nozzle forming step S1, the back surface supply path forming step S2, the lid member forming step S3, and the cutting step S4 is not limited to the example of FIG. 10, and the lid is formed before the joining step S5. What is necessary is just to be able to implement member formation process S3.

(Second Embodiment)
FIG. 11 and FIG. 12 are explanatory diagrams of the liquid discharge unit 300 according to the second embodiment of the present invention. The same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. 11 is an exploded perspective view of the liquid discharge unit 300, and FIG. 12 is an exploded plan view of the liquid discharge unit 300.

  In the present embodiment, the first common supply channel 17 and the second common supply channel 32 communicate with each other at a position on one end side of the discharge port array 16, and the first common recovery channel 18 at a position on the other end side. And the second common recovery flow path 33 communicate with each other. In this embodiment, since the third flow path layer 24 in the first embodiment is not provided, and the first supply port 30 and the first recovery port 31 in the first embodiment can be omitted, the flow path structure is simplified. be able to.

(Third embodiment)
FIG. 13 and FIG. 14 are explanatory diagrams of a liquid ejection unit 300 according to the third embodiment of the present invention. The same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. 13 is an exploded perspective view of the liquid discharge unit 300, and FIG. 14 is an exploded plan view of the liquid discharge unit 300.

  In the present embodiment, the first common supply channel 17 and the first supply port 30 communicate with each other and the first common recovery channel 18 and the first collection port 31 communicate with each other at a position on one end side of the discharge port array 16. doing. Similarly, at the position on the other end side of the discharge port array 16, the first common supply channel 17 and the first supply port 30 communicate with each other, and the first common recovery channel 18 and the first collection port 31 communicate with each other. doing. By disposing the first supply port 30 and the first recovery port 31 at both ends of the ejection port array 16, the ink circulation flow rate in the first direction in which the ejection port array 16 extends is greater than in the second embodiment. Variations and variations in pressure within each pressure chamber 13 can be suppressed. Furthermore, the second common supply channel 32 and the second common recovery channel 33 need only be provided two by two.

  As described above, in this embodiment, the number of the first supply ports 30 and the second recovery ports 31 can be reduced, and the structure of the ink flow path can be simplified.

(Fourth embodiment)
FIGS. 15 to 18 are explanatory views of a liquid discharge unit 300 according to the fourth embodiment of the present invention. The same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 15 is an exploded perspective view of the liquid discharge unit 300, and FIG. 16 is an exploded plan view of the liquid discharge unit 300. The planar shape of the liquid ejection unit 300 in the present embodiment is a parallelogram (a parallelogram whose adjacent sides are not perpendicular), but the planar shape is illustrated as a rectangle for ease of explanation. FIG. 17A is a plan view of the liquid discharge substrate 100 in the present embodiment, and FIG. 17B is a perspective view for explaining the structure of the end portion of the discharge port array 16.

  As shown in FIG. 17A, the liquid ejection substrate 100 in the present embodiment has a parallelogram shape in plan view, and the liquid ejection substrate 100 in FIG. 7A in the first embodiment. In comparison, the region a between the end of the ejection port array 16 and the end of the element substrate is small. In the present embodiment, the drive circuit such as the connection pad 150 and the ejection energy generating element 12 for transmitting and receiving electrical signals between the liquid ejection substrate 100 and the outside includes the liquid ejection as shown in FIG. It is arranged on the long side of the substrate 100 for use. When a long recording head (line head) is configured by combining such liquid discharge substrates 100, the liquid discharge substrates 100 are not staggered but substantially as shown in FIG. Can be arranged in a row. With such an arrangement, the end portions of the discharge port arrays 16 in the liquid discharge substrates 100 adjacent to each other can be easily overlapped in the upper and lower second directions in FIG. Here, “substantially arranged in one row” means that the liquid discharge substrates 100 adjacent to each other are partially overlapped in both the first direction and the second direction. .

  As described above, in the present embodiment, the discharge port 11 is arranged near the end of the liquid discharge substrate 100. In such a form, as shown in FIGS. 7B and 7C in the first embodiment, the first supply port 30 or the position overlapping the end of the discharge port array 16 of the liquid discharge substrate 100 is used. It is difficult to arrange the first recovery port 31. Therefore, in the present embodiment, as shown in FIG. 17B, the first supply port 30 or the first recovery port 31 is arranged at a position shifted to the center side from the end of the discharge port array 16.

  In the present embodiment, in order to suppress variations in the ink circulation flow rate and pressure in each pressure chamber 13 and further to suppress the temperature distribution in the liquid discharge substrate 100, as shown in FIGS. The first supply ports 30 are provided in the vicinity of both ends of the first supply port 30.

  When the 1st supply port 30 is arrange | positioned near the edge part of the discharge outlet row | line | column 16 like this embodiment, the 1st common supply flow path 17 located in the edge part of the discharge outlet row | line | column 16 and the 1st common recovery flow The differential pressure with respect to the path 18 is greater during ink ejection than during ink circulation due to the initial differential pressure. On the other hand, when the first recovery port 31 is disposed at the end of the discharge port array 16 as in the first embodiment, the first common supply flow path 17 at the end of the discharge port array 16 and the first common The differential pressure with the recovery flow path 18 is smaller when ink is ejected than when ink is circulated by the initial differential pressure. When the differential pressure between the first common supply channel 17 and the first common recovery channel 18 decreases, the ink circulation flow rate decreases, and the influence of the evaporation of moisture in the ink from the ejection port 11, that is, the ink ejection speed. The effect of suppressing the decrease and the change in the ink color material density is reduced. Therefore, it is better that the differential pressure is large. By providing the first supply ports 30 in the vicinity of both ends of the ejection port array 16 as in the present embodiment, it is possible to reduce the influence of variations in the ink circulation flow rate.

  The pressure in the first supply port 30 is set to be higher than the pressure in the first recovery port 31 in order to generate an ink circulation flow, and the ink is discharged into the pressure chamber 13 through the first supply port 30. Ink can be supplied easily. By disposing the first supply port 30 that facilitates the supply of ink in the vicinity of the end of the discharge port array 16 as described above, when the ink is simultaneously discharged from the large number of discharge ports 11, the first common supply channel 17. And the pressure loss which arises in the 1st common recovery flow path 18 can be made small.

  In the present embodiment, as described above, since the region a between the end portion of the discharge port array 16 and the end portion of the element substrate is small, the extent to which the heat generated during ink discharge is dissipated from the region a is small. Since the region a is small, the portion of the first common supply channel 17 between the first supply port 30 and the end of the discharge port array 16 becomes longer as shown in FIG. The portion of the first common recovery flow path 18 from the first recovery port 31 to the end of the discharge port array 16 becomes longer. Therefore, the ink passing through the first common supply flow path 17 and the first common recovery flow path 18 easily receives heat from the liquid discharge substrate 100. For this reason, when ink is simultaneously ejected from a large number of ejection ports 11, the temperature of the end portion of the ejection port array 16 tends to be higher than other portions. In addition, when ink is ejected, the pressure loss that occurs in each ink flow path also increases, and the pressure variation increases at the end of the ejection port array 16.

  However, in the present embodiment, as described above, the first supply ports 30 are arranged at both ends of the discharge port array 16, so that the discharge ports 11 near the ends of the discharge port array 16 are not A large amount of ink is supplied from the first supply port 30 disposed in the vicinity thereof. As a result, when ink is simultaneously ejected from a large number of ejection ports 11, the amount of high-temperature ink supplied from the first supply port 30 is reduced, and the temperature rise at the end of the ejection port array 16 can be reduced. it can.

  Specifically, the ink supplied from the first supply port 30 first enters the supply channel 14 from the first common supply channel 17 as indicated by an arrow B1 in FIG. Thereafter, the ink passes through the pressure chamber 13 and the recovery channel 15 located at the end of the discharge port array 16 as indicated by an arrow B2, and then passes through the first common recovery channel 18 as indicated by an arrow B3. Recover from the first recovery port 31.

  As described above, in the present embodiment, by disposing the first supply ports 30 at both ends of the ejection port array 16, variation in ink circulation flow rate and pressure is suppressed, and temperature distribution in the recording head is also achieved. Can be kept small. Therefore, a reduction in ink discharge speed due to evaporation of moisture in the ink from the discharge port 11 and a change in ink color material density are suppressed, and variations in ink discharge characteristics are suppressed, resulting in higher definition and higher quality. Images can be recorded. Furthermore, it is preferable that the first common supply channel 17 and the first common recovery channel 18 in the present embodiment have a shape as shown in FIG. 18A is a view of the liquid discharge substrate 100 as seen from the back side, and FIG. 18B is a diagram illustrating the first common supply channel 17 and the first common recovery channel 18 in FIG. 18A. It is an enlarged view of the edge part of the longitudinal direction. Both end portions in the longitudinal direction of the first common supply channel 17 and the first common recovery channel 18 communicating with the same discharge port array 16 are aligned as shown in FIG. Further, as shown in FIG. 18 (a), in the two discharge port arrays 16 juxtaposed so as to be adjacent to each other, the first common supply channel 17 and the first common recovery channel 18 on one side, and the other side The first common supply channel 17 and the first common recovery channel 18 are in the following positional relationship. That is, the first common supply flow path 17 that communicates with one of the discharge port arrays 16 adjacent to each other, both longitudinal ends of the first common recovery flow path 18, and the first common supply flow path 17 that communicates with the other direction. The positions of the first common recovery channel 18 and the both ends in the longitudinal direction are obliquely displaced.

  The end portions of the flow channels 17 and 18 and the liquid discharge substrate 100 are secured by the flow channels 17 and 18 having such a shape while ensuring the supply of ink to the discharge ports 11 located at both ends of the discharge port array 16. The strength of the liquid discharge substrate 100 can be ensured by increasing the width between the two end portions. More specifically, in FIG. 18A, the distance between the right end of the flow path 17 and the right end of the liquid discharge substrate 100 is set large, and the left end of the flow path 18 and the liquid discharge are set. The distance between the left end portion of the substrate 100 can be set large. Further, as shown in FIG. 18B, both end portions of the first common supply flow channel 17 and the first common recovery flow channel 18 in the longitudinal direction have shapes with corners dropped. In the case of this example, the corner is chamfered, but it may be R-shaped. By adopting such a shape, when strain or external force due to heat is applied, the stress concentration generated at both ends of the first common supply channel 17 and the first common recovery channel 18 is suppressed, and a liquid caused by cracks or the like is suppressed. Damage to the discharge substrate 100 can be suppressed.

(Fifth embodiment)
FIG. 19 and FIG. 20 are explanatory diagrams of a liquid ejection unit 300 according to the fifth embodiment of the present invention. The same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 19 is an exploded perspective view of the liquid discharge unit 300, and FIG. 20 is an exploded plan view of the liquid discharge unit 300.

  In this example, as shown in FIG. 19, three first common supply flow paths 17 (17A, 17B, 17C) and two first sets are provided for four discharge port arrays 16 (16A, 16B, 16C, 16D). A common recovery channel 18 (18A, 18B) is arranged. As shown in FIG. 20, a common recovery channel 15 is disposed between the discharge port arrays 16A and 16B, and the recovery channel 15 communicates with the first common recovery channel 18A. Further, a common supply channel 14 is disposed between the ejection port arrays 16B and 16C, and the supply channel 14 communicates with the first common supply channel 17A. Further, a common recovery channel 15 is disposed between the discharge port arrays 16C and 16D, and the recovery channel 15 communicates with the first common recovery channel 18B. The supply channel 14 of the discharge port array 16A communicates with the first common supply channel 17A, and the supply channel 14 of the discharge port array 16D communicates with the first common supply channel 17C.

  As described above, one first common supply channel 17B communicates with the pressure chambers 13 of the discharge port arrays 16B and 16C via the supply channel 14 common to the two discharge port arrays 16B and 16C. doing. One first common recovery flow path 18A communicates with the pressure chambers 13 of the discharge port arrays 16A and 16B via the recovery flow path 15 common to the two discharge port arrays 16A and 16B. Yes. Similarly, one first common recovery flow path 18B communicates with the pressure chambers 13 of the discharge port arrays 16C and 16D via the recovery flow path 15 common to the two discharge port arrays 16C and 16D. ing.

  According to this embodiment, in addition to the effects of the above-described embodiments, the following effects can be achieved.

  That is, the two ejection port arrays adjacent to each other share the first common supply channel 17 and the first common recovery channel 18, thereby reducing the number of partition walls and ink channels between the ink channels. . Therefore, it is possible to reduce the interval between the ejection port arrays 16 and increase the width of the ink flow path. As a result, variations in the ink circulation flow rate and pressure in each pressure chamber 13 are further suppressed, and the ejection port arrays 16 are arranged at a higher density than in the above-described embodiment, thereby reducing the size of the substrate H and thus the print head. can do. Further, when the arrangement density of the ejection port arrays 16 is the same, the variation in the ink circulation flow rate and pressure in each pressure chamber 13 is further suppressed, and the number of the first supply ports 30 and the first recovery ports 31 is reduced. Therefore, the ink flow path structure on the substrate H can be simplified.

(Sixth embodiment)
FIG. 21 to FIG. 23 are explanatory diagrams of a liquid ejection unit 300 according to the sixth embodiment of the present invention. The same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 21 is an exploded perspective view of the liquid discharge unit 300, and FIG. 22 is an exploded plan view of the liquid discharge unit 300.

  In the present embodiment, in order to eject different colors or different types of ink into one substrate H, an ejection port array in which ejection ports 51 for first ink are arranged and an ejection port 61 for second ink are provided. An array of ejection outlets is formed. The second channel layer 23 includes a first common supply channel 52 for the first ink, a first common supply channel 62 for the second ink, a first common recovery channel 53 for the first ink, and a first A first common recovery channel 63 for two inks is formed. The third flow path layer 24 is provided with a first ink supply port 54, a second ink supply port 64, a first ink recovery port 55, and a second ink recovery port 65. . The fourth flow path layer 25 includes a second common supply flow path 56 for the first ink, a second common supply flow path 66 for the second ink, a third common recovery flow path 57 for the first ink, and a second A third common recovery channel 67 for two inks is formed. The fifth flow path layer 26 includes a second supply port 58 for the first ink, a second supply port 68 for the second ink, a second recovery port 59 for the first ink, and a second supply port for the second ink. A recovery port 69 is formed. The sixth flow path layer 27 includes a third common supply flow path 70 for the first ink, a third common supply flow path 80 for the second ink, a third common recovery flow path 71 for the first ink, and a first A third common recovery flow path 81 for two inks is formed.

  As in the first embodiment, each of the first and second inks is supplied from the third common supply flow paths 70 and 80, and after passing through the corresponding pressure chamber 13, the third common recovery flow path 71 and 81 is recovered.

  As in the fifth embodiment, one first common supply channel may be configured to communicate with the pressure chambers of the two discharge port arrays in common. You may comprise so that one 1st common collection | recovery flow path may be connected in common with respect to the pressure chamber of an exit row | line | column. Further, the width of the sixth flow path layer 27 in the second direction may be set larger than the width of the first flow path layer 22 in the second direction.

  As described above, even in the recording head for multi-color ink or multi-type ink, the ink circulation amount and pressure variation in each pressure chamber can be reduced without increasing the width of the first common supply channel and the first common recovery channel. Can be suppressed. Accordingly, it is possible to record a higher-definition and high-quality image by suppressing a decrease in the ink ejection speed due to evaporation of moisture in the ink from the ejection port and a change in the ink color material density.

(Disposition relationship between the flow paths 52 and 53 and the flow paths 62 and 63)
The arrangement relationship between the first common supply channel 52 and the first common recovery channel 53 for the first ink and the first common supply channel 62 and the first common recovery channel 63 for the second ink is as follows. It is preferable to set as follows.

  That is, as shown in FIG. 23, between the first ink discharge port array 16 (1) and the second ink discharge port array 16 (2), the first common recovery flow channel 53 and the first common supply flow channel are provided. The beam width W4 between them is set to be larger than the beam width W1. By increasing the beam width W4, ink leakage between the first common recovery flow channel 53 and the first common supply flow channel 62 can be suppressed so that ink color mixing does not occur. The beam width W3 and the beam width W4 may be the same width or different widths. In particular, the beam width W3 in the same type of ink is made smaller than the beam width W4 in different types of ink, thereby reducing the pressure loss of the flow path with respect to the ink flow and improving the ink ejection characteristics. Can do. In this way, it is possible to suppress the backflow of the ink circulation flow and to suppress the occurrence of ink color mixing while keeping the pressure in the first common supply flow path 17 at a negative pressure.

(Configuration example of liquid discharge head)
FIG. 24 is a perspective view for explaining a different configuration example of an ink jet recording head as a configuration example of a liquid discharge head to which the present invention can be applied.

  The recording head in FIG. 24A includes one liquid discharge substrate 100, and a support member 400 and the liquid discharge substrate 100 are sequentially disposed on the first flow path member 500. This recording head is used in a so-called serial scan type ink jet recording apparatus. The recording apparatus includes a recording scan in which ink is ejected from the ejection port while moving the recording head in the main scanning direction indicated by an arrow X, and a sub-scanning direction indicated by an arrow Y that intersects the main scanning direction (orthogonal in this example). The image is recorded on the recording medium by repeating the operation of conveying the recording medium. The main scanning direction is a direction intersecting (orthogonal in this example) with the first direction in which the ejection port array 16 extends.

  24B and 24C are long line heads in which a plurality of liquid discharge substrates 100 are arranged in a staggered manner. In the configuration of (b), the first flow path member 500 is arranged in common for the plurality of liquid discharge substrates 100, and in the configuration of (c), the first flow path member 500 is for liquid discharge. Each substrate 100 is individually arranged. The first flow path member 500 is disposed on the second flow path member 600. Such a recording head is used in a so-called full line type ink jet recording apparatus. The recording apparatus continuously conveys the recording medium in the arrow Y direction intersecting (orthogonal in this example) with the first direction in which the ejection port array 16 extends, and the ink from the recording head at a fixed position. Are continuously recorded on the recording medium.

  24D and 24E is a long line head in which the liquid discharge substrates 100 are arranged in a line, and is used in a so-called full line type ink jet recording apparatus. In the configuration of (d), the first flow path member 500 is arranged in common for the plurality of liquid discharge substrates 100, and in the configuration of (e), the first flow path member 500 is for liquid discharge. Each substrate 100 is individually arranged. The first flow path member 500 is disposed on the second flow path member 600. The liquid discharge substrate 100 in such a recording head is desirably shaped as in the fourth embodiment.

  In such various recording heads, by causing the ink circulation flow as described above, it is possible to suppress a decrease in the ink discharge speed due to the evaporation of moisture in the ink from the discharge port and a change in the color material concentration of the ink. High-definition and high-quality images can be recorded.

(Configuration example of recording device)
FIG. 25 is a diagram for explaining a different configuration example of an ink jet recording apparatus as a configuration example of a liquid apparatus to which the present invention can be applied.

  The inkjet recording apparatus in FIG. 25A is a serial scan type recording apparatus that uses the recording head having the configuration shown in FIG. The chassis 47 is composed of a plurality of plate-like metal members having a predetermined rigidity, and constitutes the skeleton of this recording apparatus. The chassis 47 is assembled with a feeding unit 41, a conveyance unit 42, and a carriage 46 that mounts the recording head 43 and can reciprocate in the main scanning direction indicated by the arrow X. The main scanning direction is a direction that intersects (in the present example, orthogonal) with the direction in which the ejection port array extends in the recording head 43. The feeding unit 41 automatically feeds a sheet-like recording medium (not shown) to the inside of the recording apparatus, and the conveying unit 42 feeds the recording medium fed one by one from the feeding unit 41 with an arrow Y. Transport in the sub-scanning direction. The sub-scanning direction is a direction intersecting (in the present example, orthogonal) with the main scanning direction. Such a recording apparatus performs a recording scan in which ink is ejected from an ejection port of the recording head 43 while moving the recording head 43 together with the carriage 46 in the main scanning direction, and a conveying operation in which the recording medium is conveyed in the sub-scanning direction. By repeating, an image is recorded on the recording medium. Ink is supplied to the recording head 43 from an ink tank (not shown).

  The ink jet recording apparatus of FIG. 25 (b) is a full line type recording apparatus using the long recording head 120 as shown in FIGS. 24 (b), (c), (d), and (e). A conveyance mechanism 202 that continuously conveys a sheet (recording medium) 201 in the direction of arrow Y is provided. The transport mechanism 202 may be configured to use a transport roller in addition to the configuration using the transport belt as in this example. In this example, the recording head 120 includes four recording heads 120Y, 120M, 120C, and 120B for ejecting yellow (Y), magenta (M), cyan (C), and black (Bk) inks. It has been. The ink corresponding to these recording heads 120 (120Y, 120M, 120C, 120B) is supplied. A color image can be continuously recorded on the sheet 201 by ejecting ink from the recording head 120 at a fixed position while continuously conveying the sheet 201 in the arrow Y direction.

  FIG. 25C is an explanatory diagram of an ink supply system for the recording heads 43 and 120. The ink in the first ink tank 44 is supplied to the third common supply channel 36 in the recording heads 43 and 120, passes through the pressure chamber 13, and then passes through the third common recovery channel 37 to the second ink tank 45. To be recovered. As a method of generating the ink circulation flow in the recording heads 43 and 120, for example, there is a method of using a water head difference between the first ink tank 44 and the second ink tank 45. Alternatively, there is a method in which a pressure difference is generated between the first ink tank 44 and the second ink tank 45 by controlling the pressure inside the first ink tank 44 and the second ink tank 45. Furthermore, an ink circulation flow can be generated using a pump or the like. The configuration of the ink supply system and the method for generating the ink circulation flow are not limited to this example and are arbitrary. In short, it suffices if a differential pressure generator that generates a pressure difference necessary for the circulation of ink through the pressure chamber can be configured.

  In such a recording apparatus, by generating an ink circulation flow in the recording head, it is possible to suppress a decrease in ink discharge speed due to evaporation of moisture in the ink from the discharge port and a change in ink colorant density, thereby achieving high definition. Can record high-quality images.

(First application example)
26 to 38 are diagrams for explaining a first application example to which the present invention is applicable.

(Description of inkjet recording apparatus)
FIG. 26 is a diagram showing a schematic configuration of a liquid ejection apparatus for ejecting a liquid according to the present invention, in particular, an ink jet recording apparatus (hereinafter also referred to as a recording apparatus) 1000 that performs recording by ejecting ink. The recording apparatus 1000 includes a transport unit 1 that transports the recording medium 2, and a line type (page wide type) liquid ejection head 3 that is disposed substantially orthogonal to the transport direction of the recording medium 2, and includes a plurality of recording media. This is a line type recording apparatus that performs continuous recording in one pass while conveying 2 continuously or intermittently. The liquid discharge head 3 includes a negative pressure control unit 230 that controls the pressure (negative pressure) in the circulation path, a liquid supply unit 220 that is in fluid communication with the negative pressure control unit 230, and ink supply and recovery to the liquid supply unit 220. A liquid connecting portion 111 serving as a mouth and a housing 380 are provided. The recording medium 2 is not limited to cut paper but may be a continuous roll medium. The liquid discharge head 3 is capable of full-color recording with cyan C, magenta M, yellow Y, and black K inks, and includes a liquid supply means, a main tank, and a buffer tank (a supply path for supplying liquid to the liquid discharge head 3). 27 (described later) is fluidly connected. The liquid discharge head 3 is electrically connected to an electric control unit that transmits power and a discharge control signal to the liquid discharge head 3. The liquid path and the electric signal path in the liquid discharge head 3 will be described later.

  The recording apparatus 1000 is an ink jet recording apparatus configured to circulate a liquid such as ink between a tank described later and the liquid ejection head 3. As a form of the circulation, a first circulation form that is circulated by two circulation pumps (for high pressure and low pressure) arranged on the downstream side of the liquid discharge head 3 and two forms arranged on the upstream side of the liquid discharge head 3 are used. There is a second circulation mode in which circulation is performed by a circulation pump (for high pressure and low pressure). Hereinafter, the first circulation mode and the second circulation mode of the circulation will be described.

(Description of the first circulation mode)
FIG. 27 is a schematic diagram showing a first circulation form of the circulation path applied to the recording apparatus 1000 of this application example. The liquid discharge head 3 is fluidly connected to a first circulation pump (high pressure side) 1001, a first circulation pump (low pressure side) 1002, a buffer tank 1003, and the like. In FIG. 27, for simplification of description, only the path through which one color of cyan C, magenta M, yellow Y, and black K flows is shown. A circulation path is provided in the liquid discharge head 3 and the recording apparatus main body.

  In the first circulation mode, the ink in the main tank 1006 is supplied to the buffer tank 1003 by the replenishment pump 1005, and then the liquid supply unit 220 of the liquid ejection head 3 through the liquid connection portion 111 by the second circulation pump 1004. To be supplied. Thereafter, the ink adjusted to two different negative pressures (high pressure and low pressure) by the negative pressure control unit 230 connected to the liquid supply unit 220 circulates in two flow paths on the high pressure side and the low pressure side. The ink in the liquid discharge head 3 circulates in the liquid discharge head by the action of the first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side) 1002 on the downstream side of the liquid discharge head, and the liquid connection portion 111. Then, the liquid is discharged from the liquid discharge head and returned to the buffer tank 1003.

  A buffer tank 1003 that is a sub tank is connected to the main tank 1006, has an air communication port (not shown) that communicates the inside and outside of the tank, and can discharge bubbles in the ink to the outside. A replenishment pump 1005 is provided between the buffer tank 1003 and the main tank 1006. The replenishment pump 1005 transports ink consumed by ejecting (discharging) ink from the ejection port of the liquid ejection head 3 from the main tank 1006 to the buffer tank 1003, such as recording by ink ejection and recovery of suction.

  The two first circulation pumps 1001 and 1002 draw liquid from the liquid connection portion 111 of the liquid discharge head 3 and flow it to the buffer tank 1003. As the first circulation pump, a positive displacement pump having a quantitative liquid feeding capacity is preferable. Specific examples include a tube pump, a gear pump, a diaphragm pump, and a syringe pump. For example, a general constant flow valve or a relief valve may be arranged at the pump outlet to ensure a constant flow rate. When the liquid discharge head 3 is driven, the first circulation pump (high-pressure side) 1001 and the first circulation pump (low-pressure side) 1002 are operated, so that the inside of the common supply channel 211 and the common recovery channel 212 have a predetermined flow rate, respectively. Ink flows. By flowing ink in this way, the temperature of the liquid discharge head 3 during recording is maintained at an optimum temperature. The predetermined flow rate at the time of driving the liquid discharge head 3 is preferably set to be equal to or higher than a flow rate that can be maintained so that the temperature difference between the recording element substrates 10 in the liquid discharge head 3 does not affect the recording image quality. However, if the flow rate is set too high, the negative pressure difference is increased in each recording element substrate 10 due to the pressure loss of the flow path in the liquid discharge unit 300, resulting in uneven density of the image. Therefore, it is preferable to set the flow rate in consideration of the temperature difference and the negative pressure difference between the recording element substrates 10.

  The negative pressure control unit 230 is provided in a path between the second circulation pump 1004 and the liquid discharge unit 300. The negative pressure control unit 230 controls the pressure downstream of the negative pressure control unit 230 (that is, the liquid discharge unit 300 side) even when the ink flow rate in the circulation system fluctuates due to a difference in the discharge amount per unit area. It operates to maintain a preset constant pressure. As the two negative pressure control mechanisms constituting the negative pressure control unit 230, as long as the pressure downstream of the negative pressure control unit 230 can be controlled with a fluctuation within a certain range around a desired set pressure, Any mechanism may be used. As an example, a mechanism similar to a so-called “pressure reduction regulator” can be employed. In the circulation channel in this application example, the second circulation pump 1004 pressurizes the upstream side of the negative pressure control unit 230 via the liquid supply unit 220. In this way, the influence of the water head pressure on the liquid discharge head 3 of the buffer tank 1003 can be suppressed, so that the layout flexibility of the buffer tank 1003 in the recording apparatus 1000 can be expanded.

  The second circulation pump 1004 may be any pump that has a lift pressure that is equal to or higher than a certain pressure in the range of the ink circulation flow rate that is used when the liquid discharge head 3 is driven, and a turbo pump or a positive displacement pump can be used. Specifically, a diaphragm pump or the like is applicable. Further, instead of the second circulation pump 1004, for example, a water head tank arranged with a certain water head difference with respect to the negative pressure control unit 230 can be applied. As shown in FIG. 27, the negative pressure control unit 230 includes two negative pressure adjusting mechanisms each having a different control pressure. Of the two negative pressure adjusting mechanisms, the relatively high pressure setting side (denoted as H in FIG. 27) and the relatively low pressure setting side (denoted as L in FIG. 27) are respectively disposed in the liquid supply unit 220. Via, it is connected to a common supply channel 211 and a common recovery channel 212 in the liquid discharge unit 300. The liquid discharge unit 300 is provided with a common supply channel 211, a common recovery channel 212, and individual channels 215 (individual supply channel 213, individual recovery channel 214) communicating with each recording element substrate. A negative pressure control mechanism H is connected to the common supply flow path 211, and a negative pressure control mechanism L is connected to the common recovery flow path 212, and a differential pressure is generated between the two common flow paths. Since the individual flow path 215 communicates with the common supply flow path 211 and the common recovery flow path 212, a part of the liquid passes through the internal flow path of the recording element substrate 10 from the common supply flow path 211. A flow (arrow in FIG. 27) flowing to the common recovery channel 212 is generated.

  In this way, in the liquid ejection unit 300, a part of the liquid passes through each recording element substrate 10 while flowing the liquid so as to pass through the common supply flow path 211 and the common recovery flow path 212. Flow occurs. Therefore, the heat generated in each recording element substrate 10 can be discharged to the outside of the recording element substrate 10 by the ink flowing through the common supply channel 211 and the common recovery channel 212. Further, with such a configuration, when recording is performed by the liquid ejection head 3, it is possible to cause ink to flow even in ejection ports and pressure chambers where ejection is not performed. As a result, the viscosity of the ink that has increased in viscosity within the ejection port is reduced, thereby suppressing the increase in the viscosity of the ink. Further, the thickened ink and the foreign matter in the ink can be discharged to the common recovery channel 212. For this reason, the liquid discharge head 3 of this application example can perform high-speed and high-quality recording.

(Description of second circulation mode)
FIG. 28 is a schematic diagram showing a second circulation form that is a circulation form different from the first circulation form described above, among the circulation paths in the recording apparatus of this application example. The main difference from the first circulation mode described above is that the two negative pressure control mechanisms constituting the negative pressure control unit 230 both have a pressure upstream of the negative pressure control unit 230 and a desired set pressure. It is a point to control by fluctuation within a certain range as the center. Further, as a difference from the first circulation mode, there is a point that the second circulation pump 1004 acts as a negative pressure source for depressurizing the downstream side of the negative pressure control unit 230. Further, a first circulation pump (high pressure side) 1001 and a first circulation pump (low pressure side) 1002 are arranged on the upstream side of the liquid discharge head 3, and a negative pressure control unit 230 is arranged on the downstream side of the liquid discharge head 3. This is also different.

  In the second circulation mode, the ink in the main tank 1006 is supplied to the buffer tank 1003 by the replenishment pump 1005. Thereafter, the ink is divided into two flow paths, and circulates in the two flow paths on the high pressure side and the low pressure side by the action of the negative pressure control unit 230 provided in the liquid ejection head 3. The ink divided into the two flow paths on the high-pressure side and the low-pressure side is supplied to the liquid discharge head 3 via the liquid connection portion 111 by the action of the first circulation pump (high-pressure side) 1001 and the first circulation pump (low-pressure side) 1002. To be supplied. Thereafter, the ink circulated in the liquid discharge head by the action of the first circulation pump (high-pressure side) 1001 and the first circulation pump (low-pressure side) 1002 passes through the negative pressure control unit 230 and passes through the liquid connection portion 111. It is discharged from the discharge head 3. The discharged ink is returned to the buffer tank 1003 by the second circulation pump 1004.

  In the second circulation mode, the negative pressure control unit 230 has a pressure on the upstream side (that is, the liquid discharge unit 300 side) of the negative pressure control unit 230 even if the flow rate varies due to a change in the discharge amount per unit area. The fluctuation is stabilized within a certain range around a preset pressure. In the circulation channel of this application example, the second circulation pump 1004 depressurizes the downstream side of the negative pressure control unit 230 via the liquid supply unit 220. In this way, since the influence of the water head pressure of the buffer tank 1003 on the liquid discharge head 3 can be suppressed, the selection range of the layout of the buffer tank 1003 in the recording apparatus 1000 can be widened. Instead of the second circulation pump 1004, for example, a water head tank arranged with a predetermined water head difference with respect to the negative pressure control unit 230 can be applied. In the second circulation mode, similarly to the first circulation mode, the negative pressure control unit 230 includes two negative pressure control mechanisms in which different control pressures are set. Of the two negative pressure adjustment mechanisms, the high pressure setting side (denoted as H in FIG. 28) and the low pressure setting side (denoted as L in FIG. 28) each pass through the liquid supply unit 220 and then the liquid discharge unit. 300 is connected to the common supply flow path 211 or the common recovery flow path 212. By making the pressure of the common supply flow path 211 relatively higher than the pressure of the common recovery flow path 212 by two negative pressure adjusting mechanisms, the internal flow paths from the common supply flow path 211 to the individual flow paths 215 and the inside of each recording element substrate 10 A liquid flow that flows to the common recovery channel 212 via the channel is generated.

  In such a second circulation mode, the same liquid flow state as in the first circulation mode can be obtained in the liquid discharge unit 300, but there are two advantages different from those in the first circulation mode. The first advantage is that in the second circulation mode, the negative pressure control unit 230 is disposed downstream of the liquid discharge head 3, so that dust and foreign matter generated from the negative pressure control unit 230 are transferred to the liquid discharge head 3. There are few concerns about inflow. The second advantage is that, in the second circulation mode, the maximum required flow rate supplied from the buffer tank 1003 to the liquid ejection head 3 is smaller than in the first circulation mode. The reason is as follows.

  The total of the flow rates in the common supply channel 211 and the common recovery channel 212 when circulating during recording standby is defined as a flow rate A. The value of the flow rate A is defined as the minimum flow rate required to bring the temperature difference in the liquid discharge unit 300 within a desired range when adjusting the temperature of the liquid discharge head 3 during recording standby. Further, a discharge flow rate when ink is discharged from all the discharge ports of the liquid discharge unit 300 (at the time of full discharge) is defined as a flow rate F (discharge amount per discharge port × discharge frequency per unit time × number of discharge ports).

  FIG. 29 is a schematic diagram showing the difference in the amount of ink flowing into the liquid ejection head 3 between the first circulation mode and the second circulation mode. FIG. 29A shows a standby time in the first circulation mode, and FIG. 29B shows a full discharge time in the first circulation mode. FIGS. 29 (c) to 29 (f) show the second circulation mode, and FIGS. 29 (c) and 29 (d) show the case where the flow rate F <the flow rate A, and FIGS. 29 (e) and 29 (f). Is the case where the flow rate F is greater than the flow rate A, and shows the flow rates during standby and full discharge, respectively.

  In the case of the first circulation form in which the first circulation pump 1001 and the first circulation pump 1002 having a quantitative liquid feeding capacity are arranged on the downstream side of the liquid discharge head 3 (FIGS. 29A and 29B). The total set flow rate of the first circulation pump 1001 and the first circulation pump 1002 is the flow rate A. With this flow rate A, the temperature in the liquid discharge unit 300 during standby can be managed. When total discharge is performed by the liquid discharge head 3, the total set flow rate of the first circulation pump 1001 and the first circulation pump 1002 remains at the flow rate A. However, the maximum flow rate supplied to the liquid ejection head 3 is caused by the negative pressure generated by the ejection of the liquid ejection head 3, and the flow rate F corresponding to the total ejection is added to the total flow rate A. Therefore, the maximum value of the supply amount to the liquid ejection head 3 is the flow rate A + the flow rate F because the flow rate F is added to the flow rate A (FIG. 29B).

  On the other hand, in the case of the second circulation mode in which the first circulation pump 1001 and the first circulation pump 1002 are arranged on the upstream side of the liquid discharge head 3 (FIG. 29C to FIG. 29F), recording is performed. The amount of supply to the liquid discharge head 3 required during standby is the flow rate A as in the first circulation mode. Therefore, in the second circulation mode in which the first circulation pump 1001 and the first circulation pump 1002 are arranged on the upstream side of the liquid discharge head 3, the flow rate A is greater than the flow rate F (FIG. 29C). For d)), the flow rate A is sufficient for the supply amount to the liquid discharge head 3 even during the entire discharge. At that time, the discharge flow rate from the liquid discharge head 3 is flow rate A−flow rate F (FIG. 29D). However, when the flow rate F is higher than the flow rate A (FIGS. 29 (e) and (f)), the flow rate becomes insufficient when the supply flow rate to the liquid ejection head 3 is set to the flow rate A at the time of full ejection. Therefore, when the flow rate F is higher than the flow rate A, the supply amount to the liquid ejection head 3 needs to be the flow rate F. At this time, if the full discharge is performed, the flow rate F is consumed in the liquid discharge head 3, and therefore, the discharge flow rate from the liquid discharge head 3 is hardly discharged (FIG. 29 (f)). When the flow rate F is higher than the flow rate A and discharge is performed but not all discharges, an amount obtained by subtracting the amount consumed by the discharge from the flow rate F is discharged from the liquid discharge head 3. When the flow rate A and the flow rate F are equal, the flow rate A (or flow rate F) is supplied to the liquid discharge head 3 and the flow rate F is consumed in the liquid discharge head 3. The discharge flow rate is almost not discharged.

  As described above, in the case of the second circulation mode, the total value of the set flow rates of the first circulation pump 1001 and the first circulation pump 1002, that is, the maximum value of the necessary supply flow rate is the larger value of the flow rate A or the flow rate F. Become. For this reason, as long as the liquid discharge unit 300 having the same configuration is used, the maximum value of the required supply amount (flow rate A or flow rate F) in the second circulation mode is the maximum value (flow rate) of the required supply flow rate in the first circulation mode. A + flow rate F).

  Therefore, in the case of the second circulation mode, the degree of freedom of the applicable circulation pump is increased. For example, a low-cost circulation pump having a simple configuration or a load of a cooler (not shown) installed in the main body side path is used. There is an advantage that the cost of the recording apparatus can be reduced. This advantage increases as the line head has a relatively large value of the flow rate A or the flow rate F. Among line heads, a line head having a long length in the longitudinal direction is more beneficial.

  On the other hand, however, the first circulation mode is advantageous over the second circulation mode. That is, in the second circulation mode, since the flow rate flowing through the liquid ejection unit 300 is maximum during recording standby, the smaller the amount of ejection per unit area (hereinafter also referred to as a low duty image), the more each ejection port. In this state, a high negative pressure is applied. For this reason, when the flow path width is narrow and the negative pressure is high, a high negative pressure is applied to the discharge port in a low-duty image in which unevenness is easily visible, so that many so-called satellite droplets are discharged along with the main ink droplets. It may occur and the recording quality may deteriorate.

  On the other hand, in the first circulation mode, a high negative pressure is applied to the discharge port at the time of forming an image having a large discharge amount per unit area (hereinafter also referred to as a high duty image). Even if it occurs, there is an advantage that it is difficult to visually recognize and the influence on the image is small. These two circulation modes can be selected in light of the specifications of the liquid discharge head and the recording apparatus main body (discharge flow rate F, minimum circulation flow rate A, and in-head flow path resistance).

(Description of third circulation mode)
FIG. 48 is a schematic diagram showing a third circulation form which is one form of the circulation path applied to the recording apparatus of this application example. A description of functions and configurations similar to those of the first and second circulation modes will be omitted, and different points will be mainly described.

  In this circulation path, the liquid is supplied into the liquid discharge head 3 from two places in the center of the liquid discharge head 3 and three places on one end side of the liquid discharge head 3. The liquid passes through the pressure chambers 23 from the common supply flow path 211 and is then recovered in the common recovery flow path 212 and is recovered to the outside from the recovery opening at the other end of the liquid discharge head 3. The individual flow path 213 communicates with the common supply path 211 and the common recovery flow path 212, and the recording element substrate 310 and the pressure chamber 23 arranged in the recording element substrate are provided in the path of each individual flow path 213. ing. Therefore, a part of the liquid flowing in the first circulation pump 1002 passes through the pressure chamber 23 of the recording element substrate 10 from the common supply channel 211 and flows to the common recovery channel 212 (arrow in FIG. 48). This is because a pressure difference is provided between the pressure adjustment mechanism H connected to the common supply flow path 211 and the pressure adjustment mechanism L connected to the common recovery flow path 212, so that the first circulation pump 1002 can perform the common recovery flow. This is because it is connected only to the path 212.

  In this way, in the liquid ejection unit 300, the liquid flow that passes through the common recovery channel 212 and the common recovery channel that passes from the common supply channel 211 to the pressure chamber 23 in each recording element substrate 10. A flow occurs at 212. Therefore, heat generated in each recording element substrate 310 can be discharged to the outside of the recording element substrate 310 by the flow from the common supply channel 211 to the common recovery channel 212 while suppressing an increase in pressure loss. Further, according to this circulation path, it is possible to reduce the number of pumps which are liquid transporting means as compared with the first and second circulation modes.

(Description of liquid discharge head configuration)
The configuration of the liquid ejection head 3 in the first application example to which the present invention is applicable will be described. FIG. 30A and FIG. 30B are perspective views showing the liquid discharge head 3 according to this application example. In the liquid discharge head 3, 15 recording element substrates 310 capable of discharging inks of four colors of cyan C / magenta M / yellow Y / black K are arranged on a straight line (arranged inline). This is a line type liquid discharge head. As shown in FIG. 30A, the liquid ejection head 3 includes each recording element substrate 310, a signal input terminal 91 and a power supply terminal 92 electrically connected via the flexible wiring substrate 40 and the electric wiring substrate 90. Prepare. The signal input terminal 91 and the power supply terminal 92 are electrically connected to the control unit of the recording apparatus 1000 and supply the ejection drive signal and the power necessary for ejection to the recording element substrate 310, respectively. By consolidating the wiring by the electric circuit in the electric wiring board 90, the number of the signal input terminals 91 and the power supply terminals 92 can be reduced as compared with the number of the recording element boards 310. This reduces the number of electrical connections that need to be removed when the liquid ejection head 3 is assembled to the recording apparatus 1000 or when the liquid ejection head is replaced. As shown in FIG. 30B, the liquid connection portions 111 provided at both ends of the liquid discharge head 3 are connected to the liquid supply system of the recording apparatus 1000. Accordingly, cyan C / magenta M / yellow Y / black K four color inks are supplied from the supply system of the recording apparatus 1000 to the liquid discharge head 3, and ink that has passed through the liquid discharge head 3 is supplied to the supply system of the recording apparatus 1000. It has come to be collected. As described above, the ink of each color can be circulated through the path of the recording apparatus 1000 and the path of the liquid discharge head 3.

  FIG. 31 is an exploded perspective view showing each component or unit constituting the liquid ejection head 3. The liquid discharge unit 300, the liquid supply unit 220, and the electric wiring board 90 are attached to the housing 380. The liquid supply unit 220 is provided with a liquid connection portion 111 (see FIG. 28). In addition, in the liquid supply unit 220, filters 221 for respective colors (see FIGS. 27 and 28) communicating with the openings of the liquid connection unit 111 are provided in order to remove foreign matters in the supplied ink. Yes. The two liquid supply units 220 are each provided with filters 221 for two colors. In the first circulation form as shown in FIG. 27, the liquid that has passed through the filter 221 is supplied to the negative pressure control unit 230 arranged on the liquid supply unit 220 corresponding to each color. The negative pressure control unit 230 is a unit composed of a negative pressure control valve for each color, and the inside of the supply system of the recording apparatus 1000 that is generated in accordance with the fluctuation of the liquid flow rate by the action of a valve, a spring member, or the like provided in each of the negative pressure control units. A change in pressure loss of the (supply system upstream of the liquid discharge head 3) is greatly attenuated. Thus, the negative pressure control unit 230 can stabilize the negative pressure change on the downstream side (liquid ejection unit 300 side) from the negative pressure control unit within a certain range. In the negative pressure control unit 230 for each color, two negative pressure control valves for each color are incorporated as described in FIG. The two negative pressure control valves are set to different control pressures, and the high pressure side supplies the common supply flow path 211 (see FIG. 27) in the liquid discharge unit 300, and the low pressure side supplies the common recovery flow path 212 (see FIG. 27) and the liquid supply. It communicates via the unit 220.

  The housing 380 includes a liquid discharge unit support part 381 and an electric wiring board support part 82, supports the liquid discharge unit 300 and the electric wiring board 90, and ensures the rigidity of the liquid discharge head 3. The electrical wiring board support portion 82 is for supporting the electrical wiring board 90 and is fixed to the liquid discharge unit support portion 381 by screws. The liquid discharge unit support portion 381 has a role of correcting the warp and deformation of the liquid discharge unit 300 and ensuring the relative positional accuracy of the plurality of recording element substrates 310, thereby suppressing streaks and unevenness in the recorded matter. . Therefore, it is preferable that the liquid discharge unit support portion 381 has sufficient rigidity, and the material is preferably a metal material such as SUS or aluminum, or a ceramic such as alumina. The liquid discharge unit support portion 381 is provided with openings 83 and 84 into which the joint rubber 100 is inserted. The liquid supplied from the liquid supply unit 220 is guided to the third flow path member 370 constituting the liquid discharge unit 300 via the joint rubber.

  The liquid discharge unit 300 includes a plurality of discharge modules 200 and a flow path member 210, and a cover member 130 is attached to the surface of the liquid discharge unit 300 on the recording medium side. Here, the cover member 130 is a member having a frame-like surface provided with a long opening 131 as shown in FIG. 31. From the opening 131, the recording element substrate 10 included in the discharge module 200 and the sealing member 130 are sealed. The stop member 110 (see FIG. 35 described later) is exposed. The frame portion around the opening 131 functions as a contact surface of a cap member that caps the liquid ejection head 3 during recording standby. For this reason, a closed space is formed at the time of capping by applying an adhesive, a sealing material, a filler, or the like along the periphery of the opening 131 and filling the irregularities and gaps on the discharge port surface of the liquid discharge unit 300. It is preferable to do so.

  Next, the configuration of the flow path member 210 included in the liquid discharge unit 300 will be described. As shown in FIG. 31, the flow path member 210 is a laminate of the first flow path member 50, the second flow path member 60, and the third flow path member 370, and allows the liquid supplied from the liquid supply unit 220 to flow. Distribute to each discharge module 200. The flow path member 210 is a flow path member for returning the liquid circulating from the discharge module 200 to the liquid supply unit 220. The flow path member 210 is fixed to the liquid discharge unit support portion 381 with screws, thereby suppressing warpage and deformation of the flow path member 210.

  FIGS. 32A to 32F are views showing the front and back surfaces of each flow path member of the first to third flow path members. FIG. 32A shows the surface of the first flow path member 50 on the side where the discharge module 200 is mounted, and FIG. 32F shows the liquid discharge unit support portion 381 of the third flow path member 370. The surface on the abutting side is shown. The first flow path member 50 and the second flow path member 60 are joined so that FIG. 32B and FIG. 32C, which are contact surfaces of the respective flow path members, face each other. The member and the third flow path member are joined so that FIG. 32D and FIG. 32E, which are contact surfaces of the respective flow path members, face each other. By joining the second flow path member 60 and the third flow path member 370, eight common flow paths (211a, 211b, 211c, extending in the longitudinal direction of the flow path member by the common flow path grooves 362 and 371 are provided. 211d, 212a, 212b, 212c, 212d) are formed. Thereby, a set of the common supply channel 211 and the common recovery channel 212 is formed in the channel member 210 for each of a plurality of ink colors (for each of a plurality of types of liquids). Ink is supplied from the common supply flow path 211 to the liquid discharge head 3, and the ink supplied to the liquid discharge head 3 is recovered by the common recovery flow path 212. The communication port 72 (see FIG. 32F) of the third flow path member 370 communicates with each hole of the joint rubber 100, and fluidly circulates with the liquid supply unit 220 (see FIG. 31). A communication port 361 (a communication port 361-1 that communicates with the common supply channel 211 and a communication port 361-2 that communicates with the common recovery channel 212) is formed on the bottom surface of the common channel groove 362 of the second channel member 60. A plurality of channels are formed and communicate with one end of the individual channel groove 352 of the first channel member 50. A communication port 351 is formed at the other end of the individual flow channel groove 352 of the first flow channel member 50, and is in fluid communication with the plurality of discharge modules 200 via the communication port 351. The individual flow channel 352 makes it possible to collect the flow channel toward the center side of the flow channel member.

  The first to third flow path members are preferably made of a material having corrosion resistance to the liquid and a low linear expansion coefficient. As the material, for example, a composite material (aluminum, LCP (liquid crystal polymer), PPS (polyphenyl sulfide), PSF (polysulfone), or modified PPE (polyphenylene ether)) as a base material and an inorganic filler such as silica fine particles or fibers added ( Resin material) can be suitably used. As a method of forming the flow path member 210, three flow path members may be laminated and bonded to each other. When a resin composite resin material is selected as the material, a joining method by welding may be used.

  FIG. 33 shows the α part of FIG. 32 (a), and the flow path in the flow path member 210 formed by joining the first to third flow path members is the first flow path member 50. It is the perspective view which expanded and showed a part from the surface side in which the discharge module 200 is mounted. The common supply flow path 211 and the common recovery flow path 212 are alternately arranged from the flow paths at both ends. Here, the connection relation of each flow path in the flow path member 210 will be described.

  The channel member 210 is provided with a common supply channel 211 (211a, 211b, 211c, 211d) and a common recovery channel 212 (212a, 212b, 212c, 212d) extending in the longitudinal direction of the liquid ejection head 3 for each color. It has been. A plurality of individual supply channels 213 (213 a, 213 b, 213 c, and 213 d) formed by the individual channel grooves 352 are connected to the common supply channel 211 of each color via a communication port 361. A plurality of individual recovery channels 214 (214a, 214b, 214c, 214d) formed by the individual channel grooves 352 are connected to the common recovery channel 212 of each color via a communication port 361. With such a flow path configuration, it is possible to collect ink from each common supply flow path 211 via the individual supply flow path 213 to the recording element substrate 10 located at the center of the flow path member. Ink can be recovered from the recording element substrate 10 to each common recovery channel 212 via the individual recovery channel 214.

  34 is a view showing a cross section taken along XXXIV-XXXIV in FIG. 33. Each individual recovery channel (214a, 214c) communicates with the discharge module 200 via a communication port 351. In FIG. 34, only the individual recovery flow paths (214a, 214c) are shown, but in another cross section, the individual supply flow path 213 and the discharge module 200 communicate with each other as shown in FIG. A flow path for supplying ink from the first flow path member 50 to the recording element 315 provided on the recording element substrate 310 is formed in the support member 330 and the recording element substrate 310 included in each ejection module 200. . Further, the support member 330 and the recording element substrate 310 are provided with a flow path for collecting (circulating) part or all of the liquid supplied to the recording element 315 to the first flow path member 50.

  Here, the common supply flow path 211 of each color is connected to the corresponding negative pressure control unit 230 (high pressure side) via the liquid supply unit 220, and the common recovery flow path 212 is connected to the negative pressure control unit 230. (Low pressure side) and the liquid supply unit 220 are connected. By this negative pressure control unit 230, a differential pressure (pressure difference) is generated between the common supply channel 211 and the common recovery channel 212. For this reason, as shown in FIGS. 33 and 34, in the liquid discharge head of this application example in which the flow paths are connected, the common supply flow path 211, the individual supply flow path 213, the recording element substrate 310, and the individual print elements are provided for each color. A sequential flow of the recovery channel 214 and the common recovery channel 212 occurs.

(Description of discharge module)
FIG. 35A is a perspective view showing one ejection module 200, and FIG. 35B is an exploded view thereof. As a manufacturing method of the discharge module 200, first, the recording element substrate 310 and the flexible wiring substrate 40 are bonded onto the support member 330 provided with the liquid communication port 31 in advance. Thereafter, the terminal 316 on the recording element substrate 310 and the terminal 341 on the flexible wiring substrate 40 are electrically connected by wire bonding, and then the wire bonding portion (electric connection portion) is covered with the sealing member 110 and sealed. . A terminal 342 on the side opposite to the recording element substrate 310 of the flexible wiring board 40 is electrically connected to a connection terminal 93 (see FIG. 31) of the electric wiring board 90. Since the support member 330 is a support member that supports the recording element substrate 310 and a flow path member that fluidly communicates the recording element substrate 310 and the flow path member 210, the support member 330 has high flatness and is sufficiently high. Those that can be reliably bonded to the recording element substrate are preferable. As a material, for example, alumina or a resin material is preferable.

(Description of structure of recording element substrate)
FIG. 36A shows a plan view of the surface of the recording element substrate 310 on which the ejection port 313 is formed, and FIG. 36B shows an enlarged view of the portion indicated by A in FIG. FIG. 36 (c) shows a plan view of the back surface of FIG. 36 (a). Here, the configuration of the recording element substrate 310 in this application example will be described. As shown in FIG. 36A, the discharge port forming member 312 of the recording element substrate 310 is formed with four discharge port rows corresponding to the respective ink colors. Hereinafter, the direction in which the discharge port array in which the plurality of discharge ports 313 are arranged is referred to as “discharge port array direction”. As shown in FIG. 36B, a recording element 315 that is a heating element for foaming a liquid by thermal energy is disposed as a discharge energy generating element at a position corresponding to each discharge port 313. A partition 322 defines a pressure chamber 323 having a recording element 315 therein. The recording element 315 is electrically connected to the terminal 316 by electrical wiring (not shown) provided on the recording element substrate 310. The recording element 315 generates heat based on the pulse signals input from the control circuit of the recording apparatus 1000 via the electric wiring board 90 (see FIG. 31) and the flexible wiring board 40 (see FIG. 35) to boil the liquid. Let The liquid is discharged from the discharge port 313 by the foaming force due to the boiling. As shown in FIG. 36B, along each discharge port array, a liquid supply path 318 extends on one side, and a liquid recovery path 319 extends on the other side. The liquid supply path 318 and the liquid recovery path 319 are flow paths provided in the recording element substrate 310 and extending in the direction of the discharge port array, and communicate with the discharge port 313 through the supply port 317a and the recovery port 317b, respectively.

  As shown in FIG. 36C, a sheet-like cover plate (lid member) 20 is laminated on the back surface of the recording element substrate 310 on which the discharge port 313 is formed, and a liquid supply path is provided on the cover plate 20. A plurality of openings 20 </ b> A communicating with 318 and the liquid recovery path 319 are provided. In this application example, three openings 20 </ b> A are provided in the cover plate 20 for one of the liquid supply paths 318 and two for one of the liquid recovery paths 319. As shown in FIG. 36B, each opening 20A of the cover plate 20 communicates with a plurality of communication ports 351 shown in FIG. The cover plate 20 is preferably one having sufficient corrosion resistance to the liquid, and high accuracy is required for the opening shape and opening position of the opening 20A from the viewpoint of preventing color mixing. For this reason, it is preferable to use a photosensitive resin material or a silicon plate as the material of the cover plate 20 and provide the opening 20A by a photolithography process. As described above, the cover plate 20 converts the pitch of the flow path by the openings 20A, and it is desirable that the cover plate 20 be formed of a film-like member in consideration of pressure loss.

  FIG. 37 is a perspective view showing a cross section of the recording element substrate 310 and the cover plate 20 in XXXVII-XXXVII in FIG. Here, the flow of the liquid in the recording element substrate 310 will be described. The cover plate 20 has a function as a lid that forms part of the walls of the liquid supply path 318 and the liquid recovery path 319 formed on the substrate 311 of the recording element substrate 310. The recording element substrate 310 includes a substrate 311 formed of Si and a discharge port forming member 312 formed of a photosensitive resin, and the cover plate 20 is bonded to the back surface of the substrate 311. A recording element 315 is formed on one surface side of the substrate 311 (see FIG. 36), and a liquid supply path 318 and a liquid recovery path 319 extending along the ejection port array are formed on the back surface side thereof. Grooves are formed. The liquid supply path 318 and the liquid recovery path 319 formed by the substrate 311 and the cover plate 20 are connected to the common supply path 211 and the common recovery path 212 in the flow path member 210, respectively. And a liquid recovery path 319 generate a differential pressure. When the recording is performed by discharging the liquid, the liquid in the liquid supply path 318 provided in the substrate 311 is supplied to the supply port 317a, the pressure chamber 323, and the recovery port at the discharge port that does not discharge the liquid. It flows to the liquid recovery path 319 via 317b (arrow C in FIG. 37). By this flow, the thickened ink, bubbles, foreign matters, and the like generated by evaporation from the ejection port 313 can be collected in the liquid collection path 319 in the ejection port 313 and the pressure chamber 323 where recording is paused. Further, the viscosity of the ink in the ejection port 313 and the pressure chamber 323 can be suppressed. The liquid recovered into the liquid recovery path 319 passes from the opening 20A of the cover plate 20 and the liquid communication port 31 (see FIG. 35B) of the support member 330 to the communication port 351 in the channel member 210, the individual recovery channel. 214 and the common recovery flow path 212 are recovered in this order. Thereafter, the recording medium 1000 is collected into the collection path. That is, the liquid supplied from the recording apparatus main body to the liquid discharge head 3 flows in the following order, and is supplied and recovered.

  The liquid first flows into the liquid ejection head 3 from the liquid connection part 111 of the liquid supply unit 220. The liquid is the joint rubber 100, the communication port 72 and the common flow channel groove 371 provided in the third flow channel member, the common flow channel groove 362 and the communication port 361 provided in the second flow channel member, and the first flow channel. The individual communication ports 353 and the communication ports 351 provided in the member are supplied in this order. Thereafter, the pressure is supplied to the pressure chamber 323 through the liquid communication port 31 provided in the support member 330, the opening 20A provided in the cover plate 20, the liquid supply path 318 and the supply port 317a provided in the substrate 311 in this order. Of the liquid supplied to the pressure chamber 323, the liquid that has not been discharged from the discharge port 313 includes the recovery port 317 b and the liquid recovery path 319 provided in the substrate 311, the opening 20 </ b> A provided in the cover plate 20, and the support member 330. It flows through the liquid communication port 31 provided in the order. Thereafter, the liquid is provided in the communication port 351 and the individual flow channel 352 provided in the first flow channel member, the communication port 361 and the common flow channel 362 provided in the second flow channel member, and the third flow channel member 370. The common channel groove 371, the communication port 72, and the joint rubber 100 are sequentially flowed. Then, the liquid flows from the liquid connection part 111 provided in the liquid supply unit 220 to the outside of the liquid discharge head 3.

  In the form of the first circulation form shown in FIG. 27, the liquid flowing in from the liquid connecting portion 111 is supplied to the joint rubber 100 after passing through the negative pressure control unit 230. In the second circulation form shown in FIG. 28, the liquid recovered from the pressure chamber 323 passes through the joint rubber 100 and then passes through the negative pressure control unit 230 from the liquid connection unit 111 to the liquid discharge head. Flow outside. Further, not all the liquid that has flowed from one end of the common supply channel 211 of the liquid discharge unit 300 is supplied to the pressure chamber 323 via the individual supply channel 213a. That is, there is a liquid that flows from one end of the common supply channel 211 and flows from the other end of the common supply channel 211 to the liquid supply unit 220 without flowing into the individual supply channel 213a. As described above, by providing the flow path without passing through the recording element substrate 310, even when the recording element substrate 310 including the fine flow path having a high flow resistance is provided as in the present application example, the liquid is provided. The reverse flow of the circulating flow can be suppressed. As described above, in the liquid discharge head 3 of this application example, it is possible to suppress the increase in the viscosity of the liquid in the pressure chamber 323 and the vicinity of the discharge port. High-quality recording can be performed.

(Description of positional relationship between recording element substrates)
FIG. 38 is a plan view partially enlarged showing the adjacent portion of the recording element substrate in two adjacent ejection modules. In this application example, a substantially parallelogram recording element substrate is used. Each ejection port array (14 a, 14 b, 14 c, 14 d) in which the ejection ports 313 in each recording element substrate 310 are arranged is disposed so as to be inclined at a certain angle with respect to the longitudinal direction of the liquid ejection head 3. In the ejection port arrays in the adjacent portions of the recording element substrates 310, at least one ejection port is overlapped in the conveyance direction of the recording medium. In FIG. 38, the two discharge ports on the line D are in a relationship of overlapping each other. With such an arrangement, even if the position of the recording element substrate 310 is slightly deviated from the predetermined position, black streaks or white spots in the recorded image can be made inconspicuous by driving control of the overlapping discharge ports. Even when a plurality of recording element substrates 310 are arranged in a straight line (in-line) instead of a staggered arrangement, the configuration shown in FIG. 38 can be used to suppress an increase in the length of the liquid ejection head in the recording medium conveyance direction. It is possible to take measures against black streaks and white spots at the connecting portions between the element substrates 310. In this application example, the main plane of the recording element substrate is a parallelogram, but the present invention is not limited to this, and the configuration of the present invention is preferable even when a recording element substrate having a rectangular shape, trapezoid, or other shape is used. Can be applied.

(Description of Modification of Liquid Discharge Head Configuration)
47 and 49 to 51, a modified example of the liquid discharge head configuration described above will be described. A description of the same configuration and function as those in the above-described example will be omitted, and different points will be mainly described. In this modification, as shown in FIGS. 47 and 49, a plurality of liquid connection portions 111, which are liquid connection portions between the liquid discharge head 3 and the outside, are collectively arranged on one end side in the longitudinal direction of the liquid discharge head. Has been. A plurality of negative pressure units 230 are collectively arranged on the other end side of the liquid discharge head 3 (FIG. 50). The liquid supply unit 220 included in the liquid discharge head 3 is configured as a long unit corresponding to the length of the liquid discharge head 3 and includes a flow path and a filter 221 corresponding to the four colors of liquid to be supplied. As shown in FIG. 50, the positions of the openings 83 to 86 provided in the liquid discharge unit support portion 81 are also provided at positions different from those of the liquid discharge head 3 described above.

  FIG. 51 shows a stacked state of the flow path members 50, 60, and 70. A plurality of recording element substrates 10 are linearly arranged on the upper surface of the channel member 50 that is the uppermost layer of the plurality of channel members 50, 60, 70. The flow paths communicating with the openings 21 (FIG. 19) formed on the back side of each recording element substrate 10 are two individual supply flow paths 213 and one individual recovery flow path 214 for each liquid color. Yes. Correspondingly, the opening 21 formed in the lid member 20 provided on the back surface of the recording element substrate 10 also has two supply openings 21 and one recovery opening 21 for each liquid color. As shown in FIG. 51, common supply channels 211 and common recovery channels 212 extending along the longitudinal direction of the liquid ejection head 3 are alternately arranged in parallel.

(Second application example)
Hereinafter, the configurations of an inkjet recording apparatus 2000 and a liquid discharge head 2003 according to a second application example to which the present invention can be applied will be described with reference to the drawings. In the following description, parts different from the first application example will be mainly described, and description of similar parts will be omitted.

(Description of inkjet recording apparatus)
FIG. 46 is a diagram showing an ink jet recording apparatus 2000 to which the present invention can be applied and performs recording by discharging a liquid. The recording apparatus 2000 according to this application example performs full-color recording on a recording medium by arranging four monochromatic liquid ejection heads 2003 corresponding to each ink of cyan C, magenta M, yellow Y, and black K in parallel. Is different from the first application example. In the first application example, the number of discharge port rows that can be used per color is one, whereas in this application example, the number of discharge port rows that can be used per color is 20. For this reason, it is possible to perform very high-speed recording by appropriately recording the recording data to a plurality of ejection port arrays. Furthermore, even if there is a discharge port that does not discharge, reliability is improved by performing complementary discharge from the discharge ports in other rows that are in positions corresponding to the transport direction of the recording medium with respect to that discharge port. And suitable for commercial records. As in the first application example, the supply system of the recording apparatus 2000, the buffer tank 1003 (see FIGS. 27 and 28), and the main tank 1006 (see FIGS. 27 and 28) are fluids for each liquid discharge head 2003. Connected. Each liquid discharge head 2003 is electrically connected to an electric control unit that transmits power and a discharge control signal to the liquid discharge head 2003.

(Explanation of circulation route)
As in the first application example, as the liquid circulation form between the recording apparatus 2000 and the liquid discharge head 2003, the first and second circulation forms shown in FIG. 27 or FIG. 28 can be used.

(Description of liquid discharge head structure)
39A and 39B are perspective views illustrating a liquid discharge head 2003 according to this application example. Here, the structure of the liquid discharge head 2003 according to this application example will be described. The liquid discharge head 2003 is an ink jet type line recording head that includes 16 recording element substrates 2010 arranged in a straight line in the longitudinal direction of the liquid discharge head 2003 and can perform recording with one type of liquid. The liquid discharge head 2003 includes a liquid connection unit 111, a signal input terminal 91, and a power supply terminal 92, as in the first application example. However, since the liquid discharge head 2003 of this application example has more discharge port arrays than the first application example, the signal input terminal 91 and the power supply terminal 92 are disposed on both sides of the liquid discharge head 2003. This is to reduce voltage drop and signal transmission delay that occur in the wiring portion provided on the recording element substrate 2010.

  FIG. 40 is a perspective exploded view showing the liquid discharge head 2003, and shows each component or unit constituting the liquid discharge head 2003 divided for each function. The role of each unit and member and the order of liquid distribution in the liquid discharge head are basically the same as those in the first application example, but the function of ensuring the rigidity of the liquid discharge head is different. In the first application example, the liquid discharge head rigidity is mainly secured by the liquid discharge unit support portion 381, but in the liquid discharge head 2003 of the second application example, the second flow path member 2060 included in the liquid discharge unit 2300. This ensures the rigidity of the liquid discharge head. The liquid discharge unit support portion 381 in this application example is connected to both end portions of the second flow path member 2060. The liquid discharge unit 2300 is mechanically coupled to the carriage of the recording apparatus 2000, and the liquid discharge head 2003 is connected. Perform positioning. The liquid supply unit 2220 including the negative pressure control unit 2230 and the electric wiring board 90 are coupled to the liquid discharge unit support portion 381. Each of the two liquid supply units 2220 includes a filter (not shown).

  The two negative pressure control units 2230 are set so as to control the pressure with different relatively high and low negative pressures. Further, as shown in FIGS. 39 and 40, when the negative pressure control unit 2230 on the high pressure side and the low pressure side is installed at both ends of the liquid discharge head 2003, a common supply extending in the longitudinal direction of the liquid discharge head 2003 is provided. The liquid flows in the channel and the common recovery channel face each other. In such a configuration, heat exchange is promoted between the common supply channel and the common recovery channel, and a temperature difference between the two common channels is reduced. Accordingly, there is an advantage that a temperature difference in each of the recording element substrates 2010 provided along the common flow path is reduced, and recording unevenness due to the temperature difference is less likely to occur.

  Next, details of the flow path member 2210 of the liquid discharge unit 2300 will be described. As shown in FIG. 40, the flow path member 2210 is a laminate of the first flow path member 2050 and the second flow path member 2060, and distributes the liquid supplied from the liquid supply unit 2220 to each discharge module 2200. To do. The flow path member 2210 functions as a flow path member for returning the liquid circulating from the discharge module 2200 to the liquid supply unit 2220. The second flow path member 2060 of the flow path member 2210 is a flow path member in which a common supply flow path and a common recovery flow path are formed, and has a function of mainly responsible for the rigidity of the liquid discharge head 2003. For this reason, as a material of the 2nd flow path member 2060, what has sufficient corrosion resistance with respect to a liquid and high mechanical strength is preferable. Specifically, SUS, Ti, alumina or the like can be used.

  FIG. 41A is a view showing a surface of the first flow path member 2050 on which the discharge module 2200 is mounted, and FIG. 41B shows the back surface thereof, and the second flow path member 2060 is shown. It is the figure which showed the surface contact | abutted with. Unlike the first application example, the first flow path member 2050 in this application example is obtained by arranging a plurality of members corresponding to each discharge module 2200 adjacent to each other. By adopting such a divided structure, a plurality of modules can be arranged to correspond to the length of the liquid discharge head 2003. For example, a relatively long scale corresponding to the B2 size or longer The present invention can be particularly preferably applied to the liquid discharge head. As shown in FIG. 41A, the communication port 351 of the first flow path member 2050 is in fluid communication with the discharge module 2200, and as shown in FIG. The communication port 353 is in fluid communication with the communication port 361 of the second flow path member 2060. 41 (c) shows a surface of the second flow path member 60 that is in contact with the first flow path member 2050, and FIG. 41 (d) is a cross section of the central portion in the thickness direction of the second flow path member 60. FIG. 41 (e) is a diagram showing a surface of the second flow path member 2060 that comes into contact with the liquid supply unit 2220. The functions of the flow path and the communication port of the second flow path member 2060 are the same as for one color in the first application example. One of the common flow channel grooves 371 of the second flow channel member 2060 is a common supply flow channel 2211 shown in FIG. 42, which will be described later, and the other is a common recovery flow channel 2212. The longitudinal direction of the liquid discharge head 2003, respectively. The liquid is supplied from one end side to the other end side. This application example is different from the first application example, and the liquid flows in the common supply channel 2211 and the common recovery channel 2212 are in opposite directions.

  FIG. 42 is a perspective view showing a liquid connection relationship between the recording element substrate 2010 and the flow path member 2210. In the flow path member 2210, a set of a common supply flow path 2211 and a common recovery flow path 2212 extending in the longitudinal direction of the liquid discharge head 2003 are provided. The communication port 361 of the second flow path member 2060 is connected in alignment with the individual communication port 353 of the first flow path member 2050. As a result, a liquid supply channel is formed that communicates from the common supply channel 2211 of the second channel member 2060 to the communication port 351 of the first channel member 2050 via the communication port 361. Similarly, a liquid supply path that communicates from the communication port 72 of the second flow channel member 2060 to the communication port 351 of the first flow channel member 2050 via the common recovery flow channel 2212 is also formed.

  43 is a view showing a cross section taken along XLIII-XLIII in FIG. 42. The common supply channel 2211 is connected to the discharge module 2200 via the communication port 361, the individual communication port 353, and the communication port 351. Although not shown in FIG. 43, in another cross section, it is apparent with reference to FIG. 42 that the common recovery flow path 2212 is connected to the discharge module 2200 through a similar path. As in the first application example, each ejection module 2200 and the recording element substrate 2010 are formed with a flow path communicating with each ejection port, and part or all of the supplied liquid pauses the ejection operation. It can be recirculated through the outlet. Similarly to the first application example, the common supply flow path 2211 is connected to the negative pressure control unit 2230 (high pressure side), and the common recovery flow path 2212 is connected to the negative pressure control unit 2230 (low pressure side) and the liquid supply unit 2220. Connected. Therefore, a flow that flows from the common supply channel 2211 through the pressure chamber of the recording element substrate 2010 to the common recovery channel 2212 is generated by the differential pressure.

(Description of discharge module)
FIG. 44 (a) is a perspective view showing one ejection module 2200, and FIG. 44 (b) is an exploded view thereof. The difference from the first application example is that a plurality of terminals 316 are respectively arranged on both sides (each long side portion of the printing element substrate 2010) along the plurality of ejection port array directions of the printing element substrate 2010. is there. Accordingly, two flexible wiring boards 40 that are electrically connected to the recording element substrate 2010 are also arranged on one recording element substrate 2010. This is because the number of ejection port arrays provided on the recording element substrate 2010 is 20, which is significantly larger than the eight arrays in the first application example, and the maximum distance from the terminal 316 to the recording element is shortened. This is to reduce a voltage drop and a signal delay that occur in the wiring portion in the recording element substrate 2010. Further, the liquid communication port 31 of the support member 2030 is provided in the recording element substrate 2010 and is opened so as to straddle all the ejection port arrays. The other points are the same as in the first application example.

(Description of structure of recording element substrate)
FIG. 45A is a schematic diagram of the surface on which the ejection port 313 of the recording element substrate 2010 is arranged, and FIG. 45C is a schematic diagram showing the back surface of the surface of FIG. FIG. 45B is a schematic diagram showing the surface of the recording element substrate 2010 when the cover plate 2020 provided on the back side of the recording element substrate 2010 is removed in FIG. As shown in FIG. 45B, a liquid supply path 318 and a liquid recovery path 319 are alternately provided on the back surface of the recording element substrate 2010 along the discharge port array direction. Although the number of ejection port arrays is significantly increased as compared with the first application example, the essential difference from the first application example is that the terminal 316 extends in the ejection port array direction of the recording element substrate as described above. It is arranged on both sides along. A set of a liquid supply path 318 and a liquid recovery path 319 are provided for each discharge port array, and an opening 20A communicating with the liquid communication port 31 of the support member 2030 is provided in the cover plate 2020. The basic configuration is the same as that of the first application example.

  Note that the description of the application example does not limit the scope of the present invention. As an example, in this application example, the thermal method in which bubbles are generated by a heating element to discharge liquid has been described. However, the present invention is also applied to a liquid discharge head that employs a piezo method and other various liquid discharge methods. be able to.

  In this application example, the ink jet recording apparatus (recording apparatus) in which liquid such as ink is circulated between the tank and the liquid discharge head has been described, but other forms may be used. In another embodiment, for example, two tanks are provided upstream and downstream of the liquid discharge head without circulating ink, and the ink in the pressure chamber is caused to flow by flowing ink from one tank to the other tank. It may be.

  Further, in this application example, an example using a so-called line type head having a length corresponding to the width of the recording medium has been described. However, a so-called serial type liquid discharge head that performs recording while scanning the recording medium. The present invention can also be applied to. As a serial type liquid discharge head, for example, a configuration in which a recording element substrate for discharging black ink and a recording element substrate for discharging color ink are mounted one by one, but the present invention is not limited to this. That is, a mode in which a plurality of recording element substrates are arranged so that the discharge ports overlap in the discharge port array direction, and a short liquid discharge head shorter than the width of the recording medium is created, and the recording medium is scanned with respect to the recording medium It may be.

(Third application example)
The configurations of the ink jet recording apparatus 1000 and the liquid discharge head 3 according to the third application example of the present invention will be described. The liquid ejection head of the third application example is a page-wide type that performs recording in one scan on a B2 size recording medium. Since the third application example is similar in many respects to the second application example, in the following description, parts different from the second application example will be mainly described, and parts similar to the second application example will be described. Is omitted.

(Description of inkjet recording apparatus)
FIG. 52 is a schematic diagram of an ink jet recording apparatus according to this application example. The recording apparatus 1000 does not perform direct recording on the recording medium from the liquid ejection head 3, and once the liquid is ejected onto the intermediate transfer body (intermediate transfer drum 1007) to form an image, the image is recorded on the recording medium 2. This is a configuration for transferring. In the recording apparatus 1000, four single-color liquid ejection heads 3 respectively corresponding to four types of CMYK inks are arranged in an arc along the intermediate transfer drum 1007. As a result, full-color recording is performed on the intermediate transfer member, and the recorded image is appropriately dried on the intermediate transfer member and then transferred to the recording medium 2 conveyed by the paper conveying roller 1009 by the transfer unit 1008. Transcribed. The paper conveyance system of the second application example is a horizontal conveyance mainly intended for cut paper, but in this application example, it can also be applied to continuous paper supplied from a main body roll (not shown). . In such a drum transport system, it is easy to transport the paper while applying a constant tension to the paper, so that there is little transport jam even at high speed recording. For this reason, the reliability of the apparatus is improved and it is suitable for commercial printing and the like. As in the first and second application examples, the supply system of the recording apparatus 1000, the buffer tank 1003, and the main tank 1006 are fluidly connected to each liquid ejection head 3. Each liquid discharge head 3 is electrically connected to an electric control unit that transmits power and a discharge control signal to the liquid discharge head 3.

(Explanation of fourth circulation mode)
As in the second application example, as the liquid circulation path between the tank of the recording apparatus 1000 and the liquid ejection head 3, the first and second circulations shown in FIG. 27 or FIG. 28 can be applied. The circulation path shown in FIG. 53 is preferable. The main difference from the second circulation mode of FIG. 28 is that a bypass valve 1010 communicating with the flow paths of the first circulation pumps 1001 and 1002 and the second circulation pump 1004 is added. The bypass valve 1010 has a function (first function) of lowering the pressure on the upstream side of the bypass valve 1010 by opening the valve when a preset pressure is exceeded. Also, it has a function (second function) for opening and closing the valve at an arbitrary timing by a signal from the control board of the printing apparatus main body.

  By the first function, it is possible to suppress an excessive or excessive pressure from being applied to the flow path on the downstream side of the first circulation pumps 1001 and 1002 or the upstream side of the second circulation pump 1004. For example, when troubles occur in the functions of the first circulation pumps 1001 and 1002, an excessive flow rate or pressure may be applied to the liquid discharge head 3. As a result, liquid may leak from the discharge port of the liquid discharge head 3 or the joints in the liquid discharge head 3 may be broken. However, as in this application example, by adding a bypass valve to the first circulation pumps 1001 and 1002, even when excessive pressure is generated, the bypass valve 1010 is opened so that the liquid can flow upstream of each circulation pump. Since the route is opened, the above trouble can be suppressed.

  Further, due to the second function, when the circulation drive is stopped, all the bypass valves 1010 are promptly opened based on a control signal from the main body side after the first circulation pumps 1001 and 1002 and the second circulation pump 1004 are stopped. Thereby, the high negative pressure (for example, several to several tens kPa) in the downstream portion (between the negative pressure control unit 230 and the second circulation pump 1004) of the liquid discharge head 3 can be released in a short time. When a positive displacement pump such as a diaphragm pump is used as the circulation pump, a check valve is usually built in the pump. However, by opening the bypass valve, the pressure in the downstream portion of the liquid discharge head 3 can be released also from the downstream buffer tank 1003 side. Although the pressure release in the downstream portion of the liquid discharge head 3 can be performed only from the upstream side, there is a pressure loss in the upstream flow path of the liquid discharge head and in the liquid discharge head. For this reason, it takes a long time to release the pressure, and the pressure in the common flow path in the liquid discharge head 3 may drop transiently, possibly destroying the meniscus at the discharge port. By opening the bypass valve 1010 on the downstream side of the liquid discharge head 3, pressure release on the downstream side of the liquid discharge head is promoted, so that the risk of meniscus destruction of the discharge port is reduced.

(Description of liquid discharge head structure)
The structure of the liquid ejection head 3 according to the third application example of the present invention will be described. FIG. 54A is a perspective view of the liquid discharge head 3 according to this application example, and FIG. 54B is an exploded perspective view thereof. The liquid discharge head 3 includes 36 recording element substrates 10 arranged in a straight line (inline) in the longitudinal direction of the liquid discharge head 3, and is an ink jet page-wide recording head that performs recording with one color liquid. is there. Like the second application example, the liquid discharge head 3 includes a signal input terminal 91 and a power supply terminal 92, and a shield plate 132 that protects the longitudinal side surface of the head.

  FIG. 54B is a perspective exploded view of the liquid discharge head 3, and each component or unit constituting the liquid discharge head 3 is divided and displayed for each function (the shield plate 132 is not shown). The role of each unit and each member and the order of the liquid circulation in the liquid discharge head 3 are the same as in the second application example. The main differences from the second application example are the electric wiring board 90, the position of the negative pressure control unit 230, and the shape of the first flow path member. As in this application example, in the case of the liquid ejection head 3 having a length corresponding to a recording medium of B2 size, for example, the power consumption of the liquid ejection head 3 is large, so that eight electrical wiring boards 90 are provided. Each of the electrical wiring boards 90 is attached to each side surface of the long electrical wiring board support part 82 attached to the liquid discharge unit support part 81 by four.

  55A is a side view of the liquid discharge head 3 including the liquid discharge unit 300, the liquid supply unit 220, and the negative pressure control unit 230. FIG. 55B is a schematic view illustrating the flow of the liquid. ) Is a perspective view showing a cross section taken along line LVc-LVc in FIG. In order to facilitate understanding, some configurations are simplified.

  A liquid connection unit 111 and a filter 221 are provided in the liquid supply unit 220, and a negative pressure control unit 230 is integrally formed below the liquid supply unit 220. As a result, the distance in the height direction between the negative pressure control unit 230 and the recording element substrate 10 is shorter than that in the second application example. This configuration has the advantage that not only the number of flow path connection portions in the liquid supply unit 220 is reduced and the reliability against leakage of the recording liquid is improved, but also the number of parts and the number of assembly steps can be reduced.

  Further, since the water head difference between the negative pressure control unit 230 and the surface where the discharge port is formed becomes relatively small, the inclination angle of the liquid discharge head 3 as shown in FIG. 52 differs for each liquid discharge head. The present invention can be suitably applied to such a recording apparatus. Since the difference in water or the like can be reduced, the negative pressure difference applied to the discharge ports of the respective recording element substrates can be reduced even when the plurality of liquid discharge heads 3 are used at different inclination angles. In addition, since the distance between the negative pressure control unit 230 and the recording element substrate 10 is reduced, the flow resistance therebetween is reduced, so that the pressure loss difference due to the change in the flow rate of the liquid is also reduced, so that more stable negative pressure control can be performed. .

  FIG. 55B is a schematic diagram showing the flow of the recording liquid inside the liquid ejection head 3. Compared with the circulation path shown in FIG. 53, the circuit is the same, but FIG. 55B shows the flow of liquid in each component of the actual liquid discharge head 3. A pair of common supply channel 211 and common recovery channel 212 extending in the longitudinal direction of the liquid discharge head 3 are provided in the long second channel member 60. The common supply channel 211 and the common recovery channel 212 are configured such that liquid flows in directions opposite to each other, and a filter 221 is provided on the upstream side of each channel, and foreign matter that enters from the connecting portion 111 or the like. Trap. As described above, the common supply channel 211 and the common recovery channel 212 are preferable in that the temperature gradient in the longitudinal direction in the liquid discharge head 3 is reduced by flowing the liquid in the opposite direction. In FIG. 53, the flows of the common supply channel 211 and the common recovery channel 212 are shown in the same direction for the sake of simplicity.

  Negative pressure control units 230 are connected to the downstream sides of the common supply channel 211 and the common recovery channel 212, respectively. Further, in the middle of the common supply channel 211, there are branches to the plurality of individual supply channels 213a, and in the middle of the common recovery channel 212, there are branches to the plurality of individual recovery channels 213b. The individual supply channel 213 a and the individual recovery channel 213 b are formed in the plurality of first channel members 50, and each individual channel is an opening 21 of the lid member 20 provided on the back surface of the recording element substrate 10. (See FIG. 19C).

  The negative pressure control unit 230 indicated by H and L in FIG. 55B is a unit having a high pressure side (H) and a low pressure side (L). Each negative pressure control unit 230 has a back pressure type pressure adjustment mechanism set so as to control the pressure upstream of the negative pressure control unit 230 by relatively high (H) and low (L) negative pressures. It is. The common supply flow path 211 is connected to the negative pressure control unit 230 (high pressure side), and the common recovery flow path 212 is connected to the negative pressure control unit 230 (low pressure side), whereby the common supply flow path 211 and the common recovery flow path are shared. A differential pressure is generated between the flow paths 212. Due to the differential pressure, the liquid sequentially passes from the common supply channel 211 to the individual supply channel 213a, the discharge port 11 (pressure chamber 23) in the recording element substrate 10, and the individual recovery channel 213b. It flows to.

  FIG. 55 (c) is a perspective view showing a cross section taken along the line LVc-LVc in FIG. 55 (a). In this application example, each discharge module 200 includes the first flow path member 50, the recording element substrate 10, and the flexible wiring substrate 40. In the present embodiment, there is no support member 30 (FIG. 18) described in the second application example, and the recording element substrate 10 including the lid member 20 is directly bonded to the first flow path member 50. The common supply flow channel 211 provided in the second flow channel member is connected to the individual supply flow channel from the communication port 61 formed on the upper surface thereof through the individual communication port 53 formed on the lower surface of the first flow channel member 50. Liquid is supplied to 213a. Thereafter, the liquid is recovered to the common recovery flow path 212 via the pressure chamber 23 and further via the individual recovery flow path 213b, the individual communication port 53, and the communication port 61 in this order.

  Here, unlike the second application example shown in FIG. 40, the individual communication port 53 on the lower surface (the surface on the second flow channel member 60 side) of the first flow channel member 50 is provided on the second flow channel member 50. The opening is sufficiently large with respect to the communication port 61 formed on the upper surface of the. With this configuration, when the discharge module 200 is mounted on the second flow path member 60, even if the position is shifted, fluid communication is reliably performed between the first flow path member and the second flow member. . As a result, the yield at the time of manufacturing the head can be improved and the cost can be reduced.

(Other application examples)
The present invention is not limited to the ink discharge substrate, the ink jet recording head, and the ink jet recording apparatus, and can be widely applied as a liquid discharge substrate, a liquid discharge head, and a liquid discharge device for discharging various liquids. it can. The present invention can also be applied to recording apparatuses of various systems such as the full line system and serial scan system described above.

  The present invention is widely applicable to an ink jet recording apparatus that records an image using an ink jet recording head that can eject ink, and a liquid ejecting apparatus that uses a liquid ejecting head capable of ejecting various liquids. For example, the present invention can be applied to apparatuses such as printers, copying machines, facsimiles having a communication system, word processors having a printer unit, and industrial recording apparatuses combined with various processing apparatuses. It can also be used for applications such as biochip fabrication and electronic circuit printing.

11 Discharge port 12 Discharge energy generating element 13 Pressure chamber 14 Supply flow path 15 Recovery flow path 16 Discharge port array 17 First common supply flow path 18 First common recovery flow path 22 Element substrate 23 First flow path member

Claims (21)

A liquid discharge substrate comprising: a discharge port that discharges liquid; a discharge energy generating element that generates energy used to discharge liquid; and a pressure chamber that includes the discharge energy generating element therein,
The liquid discharge substrate includes a first portion and a second portion that are located in the thickness direction of the liquid discharge substrate,
A supply flow path that is disposed on one side of the pressure chamber and supplies liquid to the pressure chamber, and a recovery flow that is disposed on the other side of the pressure chamber and collects liquid from the pressure chamber. A road,
The liquid discharge substrate, wherein a common supply channel that communicates with the plurality of supply channels and a common recovery channel that communicates with the plurality of recovery channels are formed in the second portion. . The supply flow path and the recovery flow path extend in a direction intersecting the surface on which the discharge energy generating element is provided,
R is the channel resistance per unit length from the downstream end of the supply channel to the upstream end of the recovery channel through the pressure chamber, and the liquid is discharged from the discharge port. When the flow rate of the liquid flowing through the pressure chamber is Q1 and the maximum negative pressure at which the liquid can be discharged from the discharge port is P, the beam width between the common supply channel and the common recovery channel 2. The liquid discharge substrate according to claim 1, wherein W satisfies a relationship of W <(2 × P) / (Q1 × R). The supply flow path and the recovery flow path extend in a direction intersecting the surface on which the discharge energy generating element is provided,
R is the flow resistance per unit length from the downstream end of the supply flow path to the upstream end of the recovery flow path through the pressure chamber, and the liquid discharged from the discharge port Where the maximum discharge amount is Q2, and the maximum negative pressure at which liquid can be discharged from the discharge port is P, the beam width W between the common supply flow path and the common recovery flow path is W <(2 × The liquid discharge substrate according to claim 1, wherein a relationship of P) / (Q2 × R) is satisfied. A liquid discharge substrate comprising: a discharge port that discharges liquid; a discharge energy generating element that generates energy used to discharge liquid; and a pressure chamber that includes the discharge energy generating element therein,
A supply flow path that is arranged on one side of the pressure chamber and extends in a direction intersecting the surface on which the ejection energy generating element is provided;
A recovery channel disposed on the other side of the pressure chamber and extending in a direction intersecting with a surface on which the ejection energy generating element is provided;
A common supply flow path communicating with a plurality of the supply flow paths;
A common recovery flow path communicating with a plurality of the recovery flow paths;
With
R is the channel resistance per unit length from the downstream end of the supply channel to the upstream end of the recovery channel through the pressure chamber, and the liquid is discharged from the discharge port. When the flow rate of the liquid flowing through the pressure chamber is Q1 and the maximum negative pressure at which the liquid can be discharged from the discharge port is P, the downstream end of the common supply channel and the common recovery flow A liquid discharge substrate, wherein a distance W from an upstream end of the path satisfies a relationship of W <(2 × P) / (Q1 × R). A liquid discharge substrate comprising: a discharge port that discharges liquid; a discharge energy generating element that generates energy used to discharge liquid; and a pressure chamber that includes the discharge energy generating element therein,
A supply flow path that is arranged on one side of the pressure chamber and extends in a direction intersecting the surface on which the ejection energy generating element is provided;
A recovery channel disposed on the other side of the pressure chamber and extending in a direction intersecting with a surface on which the ejection energy generating element is provided;
A common supply flow path communicating with a plurality of the supply flow paths;
A common recovery flow path communicating with a plurality of the recovery flow paths;
With
R is the flow resistance per unit length from the downstream end of the supply flow path to the upstream end of the recovery flow path through the pressure chamber, and the liquid discharged from the discharge port Q2 is the maximum discharge amount and P is the maximum negative pressure at which liquid can be discharged from the discharge port, and the downstream end of the common supply channel and the upstream end of the common recovery channel The liquid discharge substrate is characterized in that the interval W satisfies the relationship of W <(2 × P) / (Q2 × R). The plurality of discharge ports are arranged to form a discharge port array extending in the first direction,
The width of the supply channel in the second direction orthogonal to the first direction is smaller than the width of the common supply channel in the second direction,
6. The liquid ejection according to claim 1, wherein a width of the recovery channel in the second direction is smaller than a width of the common recovery channel in the second direction. substrate.   The common supply channel and the common recovery channel extend along each other, and an interval W between the common supply channel and the common recovery channel is 200 um or less. 7. The liquid discharge substrate according to any one of 1 to 6.   8. The liquid discharge according to claim 1, wherein an interval between the supply channel and the recovery channel is smaller than an interval between the common supply channel and the common recovery channel. Substrate. The plurality of discharge ports are arranged to form a discharge port array extending in the first direction,
The center of the supply channel in the second direction orthogonal to the first direction is closer to the discharge port than the center of the common supply channel in the second direction,
The center of the recovery flow path in the second direction is closer to the discharge port than the center of the common recovery flow path in the second direction. Liquid discharge substrate. The plurality of discharge ports are arranged to form a discharge port array extending in the first direction,
10. The liquid discharge substrate according to claim 1, wherein the common supply flow path and the common recovery flow path extend in the first direction. 11.   The supply flow path and the recovery flow path extend in a direction intersecting a surface on which the discharge energy generating element of the liquid discharge substrate is disposed, and the common supply flow path and the common recovery flow path are The liquid discharge substrate according to claim 1, wherein the liquid discharge substrate extends in a direction along the surface. The liquid discharge substrate is a substantially parallelogram,
Both ends of the first common supply flow path communicating with the first discharge port array in which the plurality of discharge ports are arranged in the first direction and the second discharge juxtaposed with the first discharge port array 12. The liquid discharge substrate according to claim 1, wherein both ends of the second common supply flow path communicating with the outlet row are displaced with respect to the first direction.   Both ends of the first direction of at least one of the common supply channel and the common recovery channel communicating with the first discharge port array have a chamfered shape or an R shape. The liquid discharge substrate according to claim 12.   A beam width between the common supply channel and the common recovery channel that communicates with the first ejection port array in which the plurality of ejection ports are arranged is W1, and the common that communicates with the first ejection port array When the beam width between the supply flow path and the common recovery flow path communicating with the second discharge port array juxtaposed with the first discharge port array is W3, the relationship is W1 <W3. The liquid discharge substrate according to claim 1, wherein the substrate is a liquid discharge substrate. The liquid discharge substrate discharges a plurality of types of liquids,
Adjacent discharge port arrays for discharging different types of liquids with a beam width W3 between the common supply channel and the common recovery channel positioned between adjacent discharge port columns for discharging the same type of liquid 15. The relationship of W3 <W4 is satisfied, where W4 is a beam width between the common supply channel and the common recovery channel positioned between the two. 2. The liquid discharge substrate according to item 1.   A liquid discharge head comprising the liquid discharge substrate according to claim 1.   The liquid discharge head according to claim 16, wherein the liquid in the pressure chamber is circulated with the outside. A liquid discharge head according to claim 16 or 17,
Control means for controlling a plurality of the ejection energy generating elements;
Differential pressure between the common supply channel and the common recovery channel so that liquid flows through the common supply channel, the supply channel, the pressure chamber, the recovery channel, and the common recovery channel. Differential pressure generating means for generating
A liquid ejection apparatus comprising: A liquid discharge head comprising: a discharge port that discharges liquid; a discharge energy generating element that generates energy used to discharge liquid; and a pressure chamber that includes the discharge energy generating element therein.
A discharge port array in which a plurality of the discharge ports are arranged;
A first flow path communicating with one side of the pressure chamber, and a second flow path communicating with the other side;
A plurality of supply channels extending in a direction intersecting a surface on which the discharge energy generating elements are arranged and supplying a liquid to the first channel are arranged in an arrangement direction of the plurality of discharge ports Supply flow channel row,
A plurality of recovery channels that extend in the intersecting direction and recover the liquid in the second channel, and are arranged in a direction in which the plurality of discharge ports are arranged;
A common supply channel that extends in the arrangement direction of the plurality of discharge ports and communicates with the plurality of supply channels;
A common recovery flow path extending in the arrangement direction of the plurality of discharge ports and communicating with the plurality of recovery flow paths;
A liquid ejection head comprising: A plurality of the discharge port arrays are juxtaposed in a direction intersecting the arrangement direction of the plurality of discharge ports,
The liquid discharge head according to claim 19, wherein the supply flow path row and the recovery flow path row are alternately arranged with respect to a direction intersecting an arrangement direction of the plurality of discharge ports.   21. The liquid discharge head according to claim 19, wherein the liquid in the pressure chamber is circulated between the pressure chamber and the outside.

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