Patent Publication Number: US-11660867-B2

Title: Liquid ejection head

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure relates to a liquid ejection head for recording images by ejecting liquid such as ink on a recording medium. 
     Description of the Related Art 
     Various conventional recording methods using a liquid ejection head as means for recording images on a recording medium such as paper have been proposed, and examples of commercially available methods include thermal transfer, wire-dot, thermal, and ink-jet methods. 
     According to the ink jet method, ink is supplied to a liquid ejection head for forming images in various configurations. In one of the configurations, an ink tank having an ink storage chamber provided discretely from the liquid ejection head is connected to the liquid ejection head. In this way, ink in the ink tank is supplied to the liquid ejection head. In another available configuration, ink in an ink tank set in an image recording device such as a printer is supplied to a liquid ejection head through a liquid supply tube. 
     Ink is guided to a support member, on which a print element substrate is mounted, through an ink flow path formed in the case for the liquid ejection head. In the ink flow path, a sealing member of a rubber material is provided between the case and the support member to secure sealability for the ink flow path and prevent ink and air from leaking to the outside. 
     The print element substrate may be provided with a plurality of ejecting element rows for individually ejecting ink of different colors (such as cyan (C), magenta (M), and yellow (Y)). The case has an ink outlet port for discharging the ink from the ink flow path. The print element substrate has an ink inlet port into which the ink flowing out of the ink outlet port of the case flows. It is suggested to individually seal the periphery of the part where the ink outlet port and the ink inlet port communicate with each other by the sealing member (Japanese Patent Application Publication No. 2015-226988). 
     SUMMARY OF THE INVENTION 
     According to the disclosure of Japanese Patent Application Publication No. 2015-226988, when ejection element rows are arranged at least at prescribed intervals, an ink outlet port and an ink inlet port may be provided for each of the ejection element rows, and the periphery of the part where the ink outlet port and the ink inlet part are in communication may be individually sealed. However, when the spacing between the ejection element rows is reduced as the size of the print element substrate is reduced, the sealing openings of sealing members may interfere with one another, which makes it difficult to secure sufficient sealing openings, and desired sealing performance may not be provided. As a result, air and ink may be leaked from the ink flow paths. 
     Meanwhile, when an ink inlet port is provided in a position which allows a sufficient sealing opening for desired sealing performance to be obtained, the degree of flexibility in arranging ink inlet ports may be lowered. The ink inlet ports must be arranged in an optimum position in order to provide high bubble removability in the ink flow paths, and it is therefore undesirable that the arrangement of the ink inlet ports is limited because of the constraint related to sealing performance for the ink inlet ports. 
     With the foregoing in view, the present disclosure provides a liquid ejection head which allows a sealing opening to be secured for a sealing part when the spacing between the liquid discharge rows is reduced. 
     A liquid ejection head according to the present disclosure includes a flow path-forming part having a flow path for liquid supplied from a liquid reservoir and a plurality of outlet ports for discharging the liquid, a liquid ejecting unit having a plurality of inlet ports into which the liquid discharged from the plurality of outlet ports flows and a plurality of ejection element rows corresponding to the inlet ports and each having a plurality of ejection elements arranged in a row to eject the liquid, and a sealing member having a sealing opening which communicates the plurality of outlet ports and the plurality of inlet ports, the sealing member seals a portion between the flow path-forming part and the liquid ejecting unit so that the plurality of outlet ports and the plurality of inlet ports are in communication, wherein a plurality of the sealing openings are provided for the sealing member, and at least one of the plurality of sealing openings has at least two inlet ports among the plurality of inlet ports. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a perspective view of a liquid ejection head according to a first embodiment of the present disclosure; 
         FIG.  1 B  is an exploded perspective view of the liquid ejection head according to the first embodiment; 
         FIG.  2    is a cross-sectional view of the liquid ejection head and an ink tank according to the first embodiment; 
         FIG.  3 A  is a schematic view of a support member according to the first embodiment; 
         FIG.  3 B  is a schematic view of a print element substrate and ink flow paths according to the first embodiment; 
         FIG.  4    is a schematic view for illustrating the relation between ejection element rows and a direction for transporting a recording medium according to the first embodiment; 
         FIG.  5 A  is a schematic cross-sectional view of an ink supply channel according to the first embodiment; 
         FIG.  5 B  is another schematic cross-sectional view of an ink supply channel according to the first embodiment; 
         FIG.  5 C  is yet another schematic cross-sectional view of an ink supply channel according to the first embodiment; 
         FIG.  6 A  is a schematic view of an exemplary arrangement of an ink supply channel and sealing members in a conventional case; 
         FIG.  6 B  is a cross-sectional view of the exemplary arrangement of the ink supply channel and the sealing members in the conventional case; 
         FIG.  7 A  is a schematic view of another exemplary arrangement of an ink supply channel and sealing members in a conventional case; 
         FIG.  7 B  is a cross-sectional view of the exemplary arrangement of the ink supply channel and the sealing members in the conventional case; 
         FIG.  8 A  is a schematic view of an exemplary arrangement of an ink supply channel and sealing members according to the first embodiment; 
         FIG.  8 B  is a cross-sectional view of an exemplary arrangement of the ink supply channel and the sealing members according to the first embodiment; 
         FIG.  9 A  is a schematic view of an exemplary arrangement of an ink supply channel and sealing members according to a second embodiment of the present disclosure; 
         FIG.  9 B  is a cross-sectional view of an exemplary arrangement of the ink supply channel and the sealing members according to the second embodiment; 
         FIG.  10 A  is a schematic view of an exemplary arrangement of an ink supply channel and sealing members according to a modification; 
         FIG.  10 B  is a cross-sectional view of the exemplary arrangement of the ink supply channel and the sealing members according to the modification; and 
         FIG.  11    is a cross-sectional view of another exemplary arrangement of an ink supply channel and sealing members according to the modification. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Preferred embodiments of the present disclosure will be described in conjunction with the accompanying drawings. Note however that the sizes, materials, and shapes of components and the positional relation thereof in the following description should be changed as appropriate depending on the configuration of the device to which the invention is applied and various other conditions. Therefore, the following description is not intended to limit the scope of the invention. As for features and steps which are not specifically shown or described, well-known features or known features in the art can be applied. The same description may not be repeated. 
     First Embodiment 
     A liquid ejection head according to a first embodiment of the present disclosure will be described. In the following description, it is assumed that the liquid ejection head is a so-called permanent type liquid ejection head which is discrete from an ink tank. The liquid ejection head in the following description may be a so-called disposable type (cartridge type) liquid ejection head which is integrated with an ink tank.  FIGS.  1 A and  1 B  show a liquid ejection head  1  for use in an image recording apparatus according to the first embodiment.  FIG.  1 A  is a perspective view of the liquid ejection head  1 , and  FIG.  1 B  is an exploded perspective view of the liquid ejection head  1 . 
     The liquid ejection head  1  according to the first embodiment has print element substrates  5  and  6  having the function of ejecting liquid such as ink and is mounted on a carriage (not shown) in the image recording apparatus to form an image by ejecting the liquid on a recording medium during scanning. Note that instead of being mounted on the carriage, the liquid ejection head  1  may be a so-called full-line type liquid ejection head in which the print element substrate is provided for the printing width. 
     The ink, which is liquid ejected for forming images, is stored in an ink tank  30  (see  FIG.  2   ) as a liquid reservoir. The ink is supplied to the liquid ejection head  1  when the ink tank is mounted to the liquid ejection head  1 . The ink supplied to the liquid ejection head  1  is supplied from a case  2  to the print element substrates  5  and  6  through a support member  4 . A sealing member  3  is provided between the flow path-forming member  2   b  of the case  2  and the support member  4  in order to secure sealability for the ink between the flow path-forming member  2   b  and the support member  4 . The flow path-forming member  2   b  is an example of a flow path-forming part which forms a flow path for the liquid supplied from the liquid reservoir. 
     A signal and power used to drive the print element substrates  5  and  6  are sent to a printed circuit board  7  through the electrical connection part of the image recording device on which the liquid ejection head  1  is mounted. The signal and the power sent to the printed circuit board  7  are supplied to the print element substrates  5  and  6  through a wiring member  8 . In response to the supplied signal and the power, print elements provided at the print element substrates  5  and  6  (elements which generate energy for ejecting the liquid such as a heater) are driven in desired timing, so that the ink is ejected from the ejecting port, and an image is formed. 
       FIG.  2    is a cross-sectional view taken along line X 1 -X 1  shown in  FIG.  1 A  and schematically illustrates the connection between the case  2  of the liquid ejection head  1  and the ink tank  30  according to the embodiment. As shown in  FIG.  2   , the ink tank  30  is mounted and secured to the case  2  as the protruding engagement part  30   a  of the ink tank  30  is engaged with the recessed engagement part  2   c  of the case  2 . When the ink tank  30  is secured to the case  2 , the ink introducing port  2   d  of the case  2  and an ink supply port  30   b  on the ink tank side are coupled. The ink tank  30  is provided with an ink absorber such as a sponge or a fiber assembly which is impregnated with and retains the ink, and the ink impregnated in the ink absorber flows from the ink supply port  30   b  through the ink introducing port  2   d  to the ink flow path formed in the case  2 . The ink then flows through the case member  2   a  of the case  2 , the flow path-forming member  2   b , the sealing member  3 , and the support member  4  to reach the print element substrates  5  and  6 . Details of the configurations of these members and other components will be later described. 
       FIG.  3 A  is a schematic view of the support member  4  and the print element substrates  5  and  6 . According to the embodiment, the liquid ejection head  1  has the two print element substrates  5  and  6 . The print element substrate  6  is provided with a plurality (six rows in the example shown in  FIG.  2   ) of ejection element rows  9   a  to  9   f  having their print elements and ejecting outlet ports for ejecting ink arranged in rows in a direction orthogonal to the scanning direction  20  by the carriage. According to the embodiment, the direction orthogonal to the scanning direction  20  corresponds to the transport direction in which a recording medium to which the ejected ink sticks is fed and discharged. The print element in the ejection element row is an example of a liquid ejection element. The support member is an example of a liquid ejecting unit having an ejection element row. 
       FIG.  3 B  is a schematic view of the ejection element rows  9   a  to  9   f  at the print element substrate  6  and ink flow paths  10   a ,  10   b , and  10   c  connected with the ejection element rows  9   a  to  9   f  The ink supplied from the ink tank flows through the ink flow paths  10   a ,  10   b , and  10   c  formed in the case  2 , is guided to immediately above the ejection element rows  9   a  to  9   f , and is supplied to the print element substrate  6 . According to the embodiment, the ink flow path  10   a  is provided as a common flow path for the two ejection element rows  9   a  and  9   f . Similarly, the ink flow path  10   b  is provided as a common flow path for the two ejection element rows  9   c  and  9   d , and the ink flow path  10   c  is provided as a common flow path for the two ejection element rows  9   b  and  9   e . As a result, the ink is supplied to the two ejection element rows from one ink flow path. The configuration of the ink flow paths  10   a  to  10   c  is not limited to the above and may be, for example, a common ink flow path provided for one or two or more ejection element rows. 
       FIG.  4    is a schematic view for illustrating the relation between the ejection element rows  9  at the print element substrate  6  and the direction for transporting the recording medium (indicated by the arrow  50 ) according to the embodiment. In each of the ejection element rows  9   a  to  9   f , a plurality of print elements are provided to be aligned in one row at prescribed intervals. The ejection element rows  9   a  to  9   f  are spaced apart and in parallel to one another. The recording medium is transported in the direction (indicated by the arrow  50 ) which is substantially orthogonal to the direction (indicated by the arrow  40 ) in which the ejection element rows  9  extend. Here, the direction which is substantially orthogonal to the extending direction refers to a direction within 10 degrees from the direction which is orthogonal to the extending direction. The recording medium can be cut paper sheets or a continuous roll of paper. 
     Referring to  FIGS.  5 A to  5 C , an ink supply channel from the case  2  to the print element substrate  6  will be described.  FIG.  5 A  is a cross-sectional view taken along line a-a in  FIG.  3 B ,  FIG.  5 B  is a cross-sectional view taken along line b-b in  FIG.  3 B , and  FIG.  5 C  is a cross-sectional view taken along line c-c in  FIG.  3 B . 
     The case  2  is made of the case member  2   a  and the flow path-forming member  2   b  which are joined together, and the ink flow paths  10   a  to  10   c  are formed as grooves provided in the flow path-forming member  2   b . Ink outlet ports  11   a ,  11   b ,  11   cd ,  11   e , and  11   f , which open downstream immediately above the corresponding ejection element rows or toward the ejection element rows, are formed at one end of the ink flow paths  10   a  to  10   c . The ink supplied from the ink tank reaches the ink outlet ports  11   a  to  11   f  corresponding to the respective ink flow paths  10   a  to  10   c  through the ink flow paths  10   a  to  10   c  in the case  2 . 
     The sealing member  3  is provided between the case  2  and the support member  4 . As shown in  FIG.  5 A , the ink outlet port  11   cd  for supplying ink to the ejection element rows  9   c  and  9   d  is provided as a common ink outlet port in the flow path-forming member  2   b . The sealing member  3  has a plurality of sealing openings which are in communication with the ink outlet port and the ink inlet port. Specifically, the sealing member  3  has a sealing opening  31   cd  in communication with the ink outlet port  11   cd  and ink inlet port  12   c  and  12   d . The sealing member  3  is provided with a sealing part  3   cd  which forms the sealing opening  31   cd . In the example shown in  FIGS.  3 A and  3 B  and  FIGS.  5 A to  5 C , the sealing member  3  has sealing parts  3   a ,  3   b ,  3   cd ,  3   e , and  3   f  for the ink outlet ports  11   a ,  11   b ,  11   cd ,  11   e , and  11   f , respectively. The support member  4  has an ink inlet port  12   d  as an upper surface opening, a common liquid chamber  13   d , and a lower surface opening  14   d  which are in communication with one another. The lower surface opening  14   d  is in communication with the ejection element row  9   d . The common liquid chamber  13   d  is a common liquid chamber for supplying ink to a plurality of ejection elements of the ejection element row  9   d  at a time. An identical liquid chamber as the common liquid chamber  13   d  is provided for the other ejection element rows  9   a  to  9   c ,  9   e , and  9   f.    
     In this manner, the ink supplied from the ink tank flows through the ink flow path  10   b  to reach the ink outlet port  11   cd  and flows out of the ink outlet port  11   cd  to the sealing opening  31   cd . The ink outlet port is an example of an outlet port from which the ink flows out. The ink flowing out of the ink outlet port  11   cd  flows through the sealing opening  31   cd  and into the ink inlet port  12   d . The ink inlet port  12   d  is an example of the inlet port into which the ink flowing out of the outlet port flows. The ink flowing into the ink inlet port  12   d  flows sequentially through the common liquid chamber  13   d  and the lower surface opening  14   d  and is guided to the ejection element row  9   d.    
     As shown in  FIG.  5 B , the ink outlet port  11   cd  is also in connection with the ink inlet port  12   c  through the sealing opening  31   cd  formed by the sealing part  3   cd . Therefore, the ink flowing through the ink flow path  10   b , after reaching the ink outlet port  11   cd , flows sequentially through the sealing opening  31   cd , the ink inlet port  12   c , the common liquid chamber  13   c , and the lower surface opening  14   c , and is also guided to the ejection element row  9   c . Similarly, as shown in  FIG.  5 C , the ink flowing through the ink flow path  10   a , after reaching an ink outlet port  11   f , flows sequentially through a sealing opening  31   f  formed by a sealing part  3   f , an ink inlet port  12   f , a common liquid chamber  13   f , and the lower surface opening  14   f , and is guided to the ejection element row  9   f.    
     The part of the ink supply channel from the ink outlet ports  11   a  to  11   f  to the ink inlet ports  12   a  to  12   f  through the sealing openings  31   a  to  31   f  formed by the sealing parts  3   a  to  3   f , which is also a feature of the present disclosure, will be described. 
       FIG.  6 A  shows an exemplary arrangement of the part from the ink outlet port to the ink inlet port via the sealing opening in the ink supply channel for a conventional liquid ejection head.  FIG.  6 A  is a cross-sectional view taken along line A-A in  FIG.  6 B , and  FIG.  6 B  is a cross-sectional view taken along line B-B in  FIG.  6 A . As shown in  FIGS.  6 A and  6 B , the conventional liquid ejection head  101  has a case  102 , a sealing member  103 , a support member  104 , and a print element substrate  105 . The case  102  has ink flow paths  110   a ,  110   b , and  110   c . Ink outlet ports  111   a ,  111   b ,  111   c ,  111   d ,  111   e , and  111   f  are provided at one end of the ink flow paths  110   a  to  110   c . Sealing parts  103   a ,  103   b ,  103   c ,  103   d ,  103   e , and  103   f  are provided in the sealing member  103 . The ink outlet ports  111   a  to  111   f  are in communication with the ink inlet ports  112   a  to  112   f , respectively, by sealing openings  131   a  to  131   f  formed by the sealing parts  103   a  to  103   f . The ink inlet ports  112   a  to  112   f  are in communication with the common liquid chambers  113   a  to  113   f  and the lower surface openings  114   a  to  114   f , respectively. 
     The print element substrate  105  is provided with a plurality of ejection element rows  109 . The ejection element rows  109  include six ejection element rows  109   a  to  109   f . As shown in  FIG.  6 A , the ejection element rows  109   a ,  109   b ,  109   c ,  109   d ,  109   e , and  109   f  correspond to the ejection element rows in rows A, B, C, D, E, and F, respectively. The ink flows through the ink flow paths  110   a  to  110   c  to reach the ink outlet ports  111   a  to  111   f . The ink is then guided to flow sequentially through the sealing parts  103   a  to  103   f , the sealing openings  131   a  to  131   f , the ink inlet ports  112   a  to  112   f , the common liquid chambers  113   a  to  113   f , and the lower surface openings  114   a  to  114   f  to reach the ejection element rows  109   a  to  109   f.    
     In this way, in the conventional liquid ejection head  101 , an ink outlet port, a sealing opening, a sealing part, an ink inlet port, a common liquid chamber, and a lower surface opening corresponding to each of the ejection element rows  109   a  to  109   f  are provided independently. As shown in  FIG.  6 A , the ink is supplied to the ejection element rows  109   a  and  109   f  through the common ink flow path  110   a . Similarly, ink is supplied to the ejection element rows  109   c  and  109   d  through the common ink flow path  110   b , and to the ejection element rows  109   b  and  109   e  through the common ink flow path  110   c . More specifically, in the arrangement shown in  FIG.  6 A , the ink of the same color (C) is ejected by the ejection element row  109   a  in the row A and the ejection element row  109   f  in the row F. Similarly, ink of the same color (M) is ejected by the ejection element row  109   b  in the row B and the ejection element row  109   e  in the row E, and ink (Y) of the same color is ejected by the ejection element row  109   c  in the row C and the ejection element row  109   d  in the row D. 
     Therefore, in the liquid ejection head  101 , when ink of the same color is ejected by a plurality of ejection element rows, ink supply channels are provided independently for the ejection element rows  109   a  to  109   f . For the ejection element rows which are adjacent to each other among the ejection element rows  109   a  to  109   f , the sealing parts  103   a  to  103   f  can be arranged without interfering with each other when a sufficient spacing is secured between the rows. Meanwhile, since the print element substrate  105  is a relatively expensive component among the components of the liquid ejection head  101 , the print element substrate  105  must be downsized in some cases in order to provide the liquid ejection head at the lowest possible cost. In such a case, the spacing between adjacent ejection element rows among the ejection element rows  109   a  to  109   f  may be reduced. 
     Therefore, as shown in  FIGS.  7 A and  7 B , the spacing between the adjacent ejection element rows is smaller than that shown in  FIGS.  6 A and  6 B . In  FIGS.  7 A and  7 B , the ink supply channels from the ink outlet ports  111   a  to  111   f  to the common liquid chambers  113   a  to  113   f  are independently provided for the ejection element rows  109   a  to  109   f .  FIG.  7 A  is a cross-sectional view taken along line C-C in  FIG.  7 B , and  FIG.  7 B  is a cross-sectional view taken along line D-D in  FIG.  7 A . 
     In this case, it is highly likely that the sealing members (in  FIG.  7 A , the sealing parts  103   c  and  103   d  and the sealing parts  103   d  and  103   e ) provided in the adjacent ejection element rows among the sealing parts  103   a  to  103   f  interfere with each another. Meanwhile, when the thickness of the sealing parts  103   a  to  103   f  is reduced in order to avoid such interference among the sealing parts  103   a  to  103   f , the sealability (sealing performance) by the sealing parts  103   a  to  103   f  may be reduced, and the possibility of leakage of supplied ink or air may increase. In order to avoid such interference among the sealing parts  103   a  to  103   f , the degree of flexibility in arranging the ink outlet ports  111   a  to  111   f  should be lowered. 
     Therefore, in the liquid ejection head  1  according to the embodiment, the sealing parts  3   a ,  3   b ,  3   cd ,  3   e , and  3   f  are formed as illustrated in  FIGS.  8 A and  8 B .  FIG.  8 A  is a cross-sectional view taken along line E-E in  FIG.  8 B , and  FIG.  8 B  is a cross-sectional view taken along line F-F in  FIG.  8 A . In the liquid ejection head  1 , ink of the same color is supplied to a plurality of ejection element rows through a common ink flow path. In other words, in the example illustrated in  FIG.  8 A , ink of the same color (C) is ejected by the ejection element row  9   a  in the row A and the ejection element row  9   f  in the row F. Similarly, ink of the same color (M) is ejected by the ejection element row  9   b  in the row B and the ejection element row  9   e  in the row E, and ink of the same color (Y) is ejected by the ejection element row  9   c  in the row C and the ejection element row  9   d  in the row D. 
     In the example shown in  FIGS.  8 A and  8 B , the ink outlet port  11   cd , the sealing opening  31   cd , and the ink inlet ports  12   c  and  12   d  are in communication with one another. The ink outlet ports  11   a ,  11   b ,  11   e , and  11   f , the sealing openings  31   a ,  31   b ,  31   e , and  31   f , and the ink inlet ports  12   a ,  12   b ,  12   e , and  12   f  are in communication with one another. Here, the ink inlet ports  12   c  and  12   d  are examples of first and second inlet ports. 
     Therefore, the ink outlet port  11   cd  supplied with the ink of the same color (Y), the sealing opening  31   cd , and the sealing part  3   cd  are shared between the two ejection element rows  9   c  and  9   d . The sealing opening  31   cd  which communicates the ink outlet port  11   cd  and the two ink inlet ports  12   c  and  12   d  is surrounded by the single sealing part  3   cd . In this way, at least two ink inlet ports are surrounded by one opening in the sealing part. Therefore, if the spacing between the ejection element rows  9   c  and  9   d  is reduced, it is unlikely that the sealability by the sealing parts is lowered by interference among the sealing parts, as is the case with the sealing parts  103   c  and  103   d  described above. Also, unlike the case shown in  FIG.  7 A , interference between the sealing part  3   cd  provided at the ejection element rows  9   c  and  9   d  for ink (Y) and the sealing part  3   e  provided in the ejection element row  9   e  for ink of a different color (M) can also be avoided. 
     In this way, according to the embodiment, interference between the sealing parts provided at the plurality of ink outlet ports supplied with ink of the same color can be avoided, while interference with the sealing part provided at the ink outlet port supplied with ink of a different color can also be avoided. As a result, it can be expected that the degree of flexibility in arranging the ink outlet ports  11   a  to  11   f  provided in the ejection element rows  9   a  to  9   f  is increased. 
     Furthermore, since the sealing part  3   cd  is provided across the plurality of ink inlet ports  12   c  and  12   d , the opening of the ink outlet port  11   cd  can be set larger than the openings of the ink outlet ports  111   c  and  111   d  in the conventional case, as can be seen from the comparison between  FIGS.  7 B and  8 B . The ink outlet port  11   cd  is formed to be wide enough to include respective regions opposed to the two ink inlet ports  12   c  and  12   d . The ink outlet port  11   cd  is an example of a first outlet port that includes respective regions opposed to at least two inlet ports. This makes it easier for air bubbles  15   cd  entering or generated in the ink flow path  10   b  to stay in the ink outlet port  11   cd  and suppresses ejection failures due to the movement of the air bubbles  15   cd  to the ejection element rows  9   c  and  9   d  on the print element substrate  6 . 
     Second Embodiment 
     A liquid ejection head according to a second embodiment of the disclosure will be described. In the following description, the same components as those in the first embodiment are designated by the same reference characters, and their detailed description will not be provided. In the liquid ejection head  1  described above, it has been found that as the ink inlet ports  12   a  to  12   f  in the support member  4  are provided in a position closer to ends of the ejection element rows  9   a  to  9   f , air bubbles generated in the ink flow paths  10   a  to  10   c  are more easily discharged. Therefore, as shown in  FIGS.  9 A and  9 B , in a liquid ejection head  200  according to the embodiment, the sealing parts  3   a ,  3   b ,  3   cd ,  3   e , and  3   f  may be provided closer to one end of the ejection element rows  9   a  to  9   d .  FIG.  9 A  is a cross-sectional view taken along line G-G in  FIG.  9 B , and  FIG.  9 B  is a cross-sectional view taken along line H-H in  FIG.  9 A . 
     In this way, it can be considered that as the ink outlet port  11   cd  is provided closer to one end of the ejection element rows  9   c  and  9   d , the air bubbles  15   cd  generated in the ink flow path  10   b  can be discharged more easily than when the ink outlet port  11   cd  is provided in the middle between the ejection element rows  9   c  and  9   d . In the example shown in  FIG.  9 A , let us focus on the ejection element rows  9   b  and  9   e  in parallel to the ejection element rows  9   c  and  9   d  corresponding to the two ink inlet ports  12   c  and  12   d . Here, the ejection element rows  9   b  and  9   e  adjacent to the ejection element rows  9   c  and  9   d  are examples of adjacent ejection element rows. The ink inlet ports  12   b  and  12   e  corresponding to the ejection element rows  9   c  and  9   d  are provided closer to the other end of the ejection element row  9   c  and  9   d  with respect to the previously mentioned one end of the ejection element row  9   c  and  9   d  provided with the ink inlet ports  12   c  and  12   d . It can be considered that as each of the ink inlet ports is provided closer to one end of the corresponding ejection element row, air bubbles generated in each of the ink flow paths  10   a  and  10   c  can be more easily discharged. Also, it is unlikely that the sealing part  3   d  which forms the sealing opening  31   cd  interferes with the sealing part  3   b  which forms the sealing opening  31   b  and the sealing part  3   e  which forms the sealing opening  31   e.    
     In the conventional liquid ejection head  101 , the ink supply channels from the ink outlet ports  111   a  to  111   f  to the common liquid chambers  113   a  to  113   f  are provided independently. In this case, it is difficult to provide the ink inlet ports  112   a  to  112   f  in the ejection element rows  109   a  to  109   f  at ends of the ejection element rows  109   a  to  109   f  in consideration of the space occupied by the sealing parts  103   a  to  103   f . Meanwhile, according to the embodiment, as in the example shown in  FIG.  9 A , the ink outlet port  11   cd  and the sealing part  3   cd  provided in the two ejection element rows  9   c  and  9   d  supplied with the ink of the same color (Y) are shared. The single sealing part  3   cd  surrounds the sealing opening  31   cd  which communicates the ink outlet port  11   cd  and the ink inlet ports  12   c  and  12   d . In this manner, the ink supply channels provided in the two ejection element rows  9   c  and  9   d  are sealed between the case  2  and the support member  4 . As a result, the ink inlet ports  12   a  to  12   f  in the ejection element rows  9   a  to  9   f  can be positioned at an end of each ejection element row, and it can be expected that the discharge performance for air bubbles generated in the ink flow paths  10   a  to  10   c  can be improved as described above. 
     In the above description, the ink outlet port  11   cd  and the sealing part  3   cd  are shared by the two ejection element rows  9   c  and  9   d  adjacent to each other. Meanwhile, according to the embodiment, an ink outlet port and a sealing part may be shared among at least two ejection element rows, and a sealing opening may be formed from one sealing part in communication with two or more ink inlet ports. 
     According to the present embodiment, even when the spacing between the rows in the ejection element rows  9   a  to  9   f  is reduced in order to downsize the print element substrate  6 , the sealability for the ink flow path can be maintained and the operation reliability of the liquid ejection head can be maintained. Therefore, according to the embodiment, a smaller and less expensive liquid ejection head can be provided while achieving the same operation stability as the conventional case. Furthermore, according to the embodiment, a high degree of flexibility in arranging the ink inlets can be provided, so that improved discharge performance for air bubbles generated in the ink flow paths can also be provided. 
     Although the embodiments according to the present disclosure have been described, the description of the embodiments are illustrated for the purpose of describing the present disclosure, and features of the present disclosure can be modified or combined as appropriate and carried out in the range without departing from the purpose of the invention. An example of modification of the above embodiment is explained below. Note that in the following description, the components identical to those of the embodiments are designated by the same reference characters and their detailed description will not be repeated. 
       FIGS.  10 A and  10 B  are cross-sectional views of the ink supply channels of a liquid ejection head according to a modification.  FIG.  10 A  is a cross-sectional view taken along line I-I in  FIG.  10 B , and  FIG.  10 B  is a cross-sectional view taken along line J-J in  FIG.  10 A . 
     According to the embodiments, the ink outlet port  11   cd  and the sealing part  3   cd  are shared between the ejection element rows  9   c  and  9   d  adjacent to each other among the ejection element rows  9   a  to  9   f  supplied with ink of the same color. In a liquid ejection head  300  according to the modification, an ink outlet port and a sealing part are shared between non-adjacent ejection element rows supplied with ink of the same color among the ejection element rows  9   a  to  9   f.    
     As shown in  FIG.  10 A , according to the modification, the ink outlet port  11   cd  and the sealing part  3   cd  are shared between the pair of ejection element rows  9   c  and  9   d  similarly to the above embodiments. In addition, an ink outlet port  11   af  and a sealing part  3   af  are also shared between the pair of ejection element rows  9   a  and  9   f  in the rows A and F across the other ejection element rows between these two ejection element rows. Also, an ink outlet port  11   be  and a sealing part  3   be  are shared between the pair of ejection element rows  9   b  and  9   e  in the rows B and E across the other ejection element rows between these two ejection element rows. 
     Then, the sealing openings  31   a  and  31   f  which communicate the ink outlet ports  11   a  and  11   f  provided in the two ejection element rows  9   a  and  9   f  supplied with ink of the same color (C) and the ink inlet ports  12   a  and  12   f  are surrounded by the single sealing part  3   af . The sealing openings  31   b  and  31   e  which communicate the ink outlet ports  11   b  and  11   e  provided in the two ejection element rows  9   b  and  9   e  supplied with ink of the same color (M) and the ink inlet ports  12   b  and  12   e  are surrounded by the single sealing part  3   be . Here, the ink inlet ports  12   a  and  12   f  are examples of third and fourth inlet ports. 
     In this way, according to the modification, the ejection element rows  9   b  to  9   e  provided corresponding to different liquid chambers  13   b  to  13   e  are provided between the ejection element rows  9   a  and  9   f  provided corresponding to the common liquid chambers  13   a  and  13   f  supplied with ink by the ink inlet ports  12   a  and  12   f . Similarly, the ejection element rows  9   c  and  9   d  are provided between the ejection element rows  9   b  and  9   e . Then, the spaces of the ink outlet ports  11   a  to  11   f  are set according to the sizes of the spaces surrounded by the sealing parts  3   af ,  3   cd , and  3   be.    
     Therefore, the spaces of the ink outlet ports  11   a  to  11   f  are larger than the spaces of the ink outlet ports  111   a  to  111   f  surrounded by the conventional sealing parts  103   a  to  103   f . As a result, it is expected that air bubbles can more easily stay in the ink flow paths  10   a  to  10   c , and ejection failures due to the air bubbles in the ejection element rows  9   a  to  9   f  can be further reduced. 
     In the above description, one common ink outlet port is provided for a plurality of ink inlet ports for example as the single ink outlet port  11   cd  is provided for the two ink inlet ports  12   c  and  12   d . Note however that one ink outlet port may be provided for one ink inlet port, and a plurality of ink inlet ports and a plurality of ink outlet ports may be provided in communication with one another through one sealing opening surrounded by one sealing part. For example, the arrangement may be as shown in  FIG.  11   .  FIG.  11    is a cross-sectional view of the arrangement corresponding to  FIG.  9 A . As shown in  FIG.  11   , two ink outlet ports  11   c  and  11   d  are provided for two ink inlet ports  12   c  and  12   d . The ink outlet ports  11   c  and  11   d  and the ink inlet ports  12   c  and  12   d  are in communication with one another through one sealing opening  31   cd  formed by one sealing part  3   cd . Also in this arrangement, the sealing part is shared among the plurality of ejection element rows, so that it can be expected that the sealing part and thus the ink outlet ports may be arranged with a higher degree of flexibility than the conventional sealing part. 
     According to the present disclosure, even when the print element substrates are downsized and the distance between the ejection element rows is reduced, a sufficient sealing opening can be secured for a sealing part and desired sealability can be provided. Then, a liquid ejection head with high sealability for liquid flow paths can be provided while the ejection element substrates are downsized and produced less expensively. 
     Other Embodiments 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2019-220471, filed Dec. 5, 2019, which is hereby incorporated by reference herein in its entirety.