JP2015116746A - Liquid discharge head and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head and a liquid discharge device that efficiently discharge concentrated ink present in the liquid discharge head in discharge and recovery processing for liquid etc.SOLUTION: A plurality of discharge ports 7 are arranged along a direction Y, pressure chamber 12 and liquid chambers 11 are alternately arranged, and flow passages 9A, 9B which extend respectively from two pressure chambers 12 having a liquid chamber 11 interposed are connected to the liquid chamber 11 interposed between the pressure chambers 12. Two connection positions where the liquid chambers 12 and the two flow passages 9A, 9B are connected are offset respectively in a direction X.

Description

  The present invention relates to a liquid discharge head capable of discharging a liquid and a liquid discharge apparatus that mounts the liquid discharge head and discharges liquid from the liquid discharge head.

  In an ink jet recording apparatus that performs recording by discharging ink onto a recording medium, a recording head having a plurality of discharge ports is mounted, and recording is performed by discharging ink from the recording head to the recording medium. The recording head of the ink jet recording apparatus imparts sufficient energy to the ink in the pressure chamber to discharge the ink droplet, and discharges the ink droplet from the discharge port formed in the pressure chamber. In this case, the recording head includes an ink supply port that communicates with the pressure chamber. When an ink droplet is ejected from the ejection port, the corresponding ink is supplied to the pressure chamber via the ink supply port. Refilled.

  As a recording head in which ink is supplied to the pressure chamber through the ink supply port, for example, there is one disclosed in Patent Document 1. Patent Document 1 describes a recording head in which ink supply ports and pressure chambers are alternately arranged in the direction in which the discharge ports are arranged. By alternately arranging the ink supply ports and the pressure chambers, ink is supplied from the ink supply ports on both sides toward the pressure chambers. In the recording head disclosed in Patent Document 1, the pressure chamber is partitioned by a plurality of columnar bodies.

JP 2010-201921 A

  In the recording head disclosed in Patent Document 1, since the pressure chamber is partitioned by a plurality of columnar bodies, normally, when ink is supplied from the ink supply port to the pressure chamber, the ink is mainly supplied by the ink. The pressure chamber is supplied through the shortest path between the mouth and the pressure chamber.

  Further, when the recording head is left for a long period of time, the water contained in the ink evaporates into the air through the discharge port and thickens around the discharge port formed in the pressure chamber. In some cases, concentrated ink having an increased density may be generated. The concentrated ink may reach the vicinity of the ink supply port by diffusing in the ink stored in the recording head.

  Concentrated ink around the ink supply port is present in the vicinity of the ink flow generated when ink is refilled from the ink supply port to the pressure chamber. It is discharged and collected. However, there is a possibility that the concentrated ink existing at a position away from the ink flow from the ink supply port to the pressure chamber at the time of ink refilling is not collected and remains inside the recording head. In this case, the concentrated ink is ejected from the ejection port when recording is performed, which may affect the recorded image.

  Therefore, in view of the above circumstances, the present invention provides a liquid discharge head and a liquid discharge apparatus that efficiently discharge concentrated ink present in the liquid discharge head when liquid discharge or recovery processing is performed. For the purpose.

  The liquid discharge head of the present invention is capable of storing a liquid therein, an energy generating element that imparts energy to the stored liquid, and a discharge port that discharges the liquid given energy by the energy generating element, A pressure chamber comprising: a supply port for supplying liquid to the pressure chamber; a liquid chamber capable of storing liquid supplied to the pressure chamber through the supply port; the pressure chamber; and the liquid chamber. A liquid flow path that is connected between the liquid chamber and guides the liquid from the liquid chamber to the pressure chamber, and the plurality of discharge ports are arranged along the first direction, and the pressure chamber and the liquid chamber Are arranged alternately, and the liquid flow path extending from each of the two pressure chambers sandwiching the liquid chamber is connected to the liquid chamber sandwiched between the pressure chambers, and the liquid chamber and the two liquids Two connection positions where the flow path is connected Relates a second direction crossing the first direction, respectively, characterized in that it is offset.

  Since the concentrated ink present in the liquid discharge head is efficiently discharged, it is possible to prevent the concentrated ink from being discharged from the discharge port when recording is performed. Thereby, when recording is performed, the density of the ink droplets ejected from the ejection port can be kept constant, and the quality of the recorded image can be kept high.

It is the perspective view shown about the inkjet recording device with which the inkjet recording head which concerns on 1st Embodiment of this invention is mounted. 1 is a perspective view showing an ink jet recording head according to a first embodiment of the present invention. FIG. 3 is a plan view showing a surface on which an ejection port is formed in the ink jet recording head of FIG. 2. FIG. 4 is a plan view showing an arrangement of a liquid chamber, a pressure chamber, and a flow path by removing an orifice plate for a part of the ejection port arrays in the ink jet recording head of FIG. 3. FIG. 5 is a cross-sectional view taken along line VV in the ink jet recording head of FIG. 4 with an orifice plate attached. FIG. 5 is an enlarged plan view showing one liquid chamber from the ink jet recording head of FIG. 4. FIG. 7 is a plan view showing a range in which concentrated ink diffuses and an ink flow in the liquid chamber in FIG. 6. It is the top view shown about the range which the concentrated ink spreads, and the flow of ink in the liquid chamber inside of a comparative example. FIG. 6 is a plan view showing the flow of ink in the liquid chamber in a modified example of the ink jet recording head according to the first embodiment. FIG. 6 is a plan view illustrating the ink flow in the liquid chamber in a further modification of the ink jet recording head according to the first embodiment. It is the top view shown about the liquid chamber of the inkjet recording head which concerns on 2nd Embodiment of this invention. It is the top view shown about the liquid chamber of the modification of the inkjet recording head which concerns on 2nd Embodiment. It is the top view shown about the liquid chamber of the further modification of the inkjet recording head which concerns on 2nd Embodiment. It is the top view which showed the discharge outlet row | line about the further modification of the inkjet recording head which concerns on 2nd Embodiment. It is the top view shown about the liquid chamber of the ink jet recording head concerning a 3rd embodiment of the present invention. It is the top view which showed the discharge port row | line | column about the inkjet recording head which concerns on 3rd Embodiment.

  Hereinafter, an ink jet recording head according to an embodiment of the present invention will be described with reference to the drawings. In addition, since embodiment described below is an appropriate specific example of this invention, various technically preferable restrictions are attached | subjected. However, the embodiments are not limited to the examples of the present specification and other specific methods as long as the idea of the present invention is met.

(First embodiment)
Hereinafter, an ink jet recording head according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an ink jet recording apparatus (liquid ejecting apparatus) 100 on which the ink jet recording head of this embodiment is mounted.

  The inkjet recording apparatus 100 according to the present embodiment includes a carriage 111 on which an inkjet recording head (liquid ejection head) and an ink tank are mounted, and a carriage drive motor 112 that moves the carriage 111 in a scanning manner. In the ink jet recording apparatus 100, when recording is performed, the ink jet recording head 19 shown in FIG. 2 is mounted inside the carriage 111 so as to face the recording medium (medium) in the carriage 111, and is not illustrated. Ink tank is installed.

  The carriage 111 is guided along the guide shaft 106 so as to be movable in the main scanning direction indicated by an arrow A. The guide shaft 106 is disposed so as to extend along the width direction of the recording medium. The ink jet recording head 19 mounted on the carriage 111 performs recording while scanning in a direction intersecting the transport direction in which the recording medium is transported by driving the carriage drive motor 112. As described above, the ink jet recording apparatus 100 is a so-called serial scan type ink jet recording apparatus that records an image with movement of the ink jet recording head 19 in the main scanning direction and conveyance of the recording medium in the sub scanning direction. Ink stored in the ink tank is supplied to the ink jet recording head 19, and recording is performed by discharging the ink supplied to the ink jet recording head 19 toward the recording medium. The ink jet recording head 19 is provided with an energy generating element for ejecting ink droplets. The recording medium is stacked on the paper feed tray 115 and then conveyed in the sub-scanning direction by a conveyance roller.

  Further, the ink jet recording apparatus 100 includes a flexible cable 113 for sending an electric signal from a control unit (not shown) to the ink jet recording head. At the time of recording, an electric signal is transmitted to the energy generating element via the flexible cable 113 at a predetermined timing according to the recording data. In this way, when the current is supplied to the energy generating element, the energy generating element is driven. In this embodiment, a heater as an electrothermal conversion element that converts electrical energy into thermal energy is used as the energy generating element. When the heater is driven, the film to which heat energy is applied causes film boiling inside the liquid chamber. As a result, ink is ejected from the ejection opening toward the recording medium, and recording is performed on the recording medium.

  The ink jet recording apparatus 100 includes a recovery processing unit 114 for performing recovery processing of the ink jet recording head. Further, the ink jet recording apparatus 100 includes an optical position sensor 116 that optically reads the position of the carriage 111. Further, the ink jet recording apparatus 100 includes a paper discharge tray 117 that holds a recording medium on which recording has been performed.

  In the inkjet recording apparatus 100 configured as described above, when recording is performed, the carriage 111 is scanned in the main scanning direction orthogonal to the conveyance direction (sub-scanning direction) of the recording medium. As described above, the inkjet recording apparatus 100 repeats the recording operation of ejecting ink while moving the recording head in the main scanning direction and the transporting operation of transporting the recording medium in the sub-scanning direction. Images are recorded in sequence. By moving the carriage 111, the ink jet recording head is moved relative to the recording medium. The inkjet recording head ejects ink droplets from the ejection port to the recording medium while moving relative to the recording medium, and recording is performed with a width corresponding to the range in which the ejection ports are formed. Further, the recording medium is intermittently conveyed by a preset conveyance amount at the time of non-recording corresponding to the non-recording area of the recording medium.

  In the above embodiment, the ink jet recording head and the ink tank are separately configured. However, the present invention is not limited to this, and the ink jet recording head and the ink tank are integrally configured. May be adopted. The ink tank may be attached to a position different from the carriage 111, and ink may be supplied from the ink tank to the ink jet recording head mounted on the carriage 111 via a tube or the like.

  The above-described recording apparatus is a so-called serial scan type recording apparatus that records an image with movement of the ink jet recording head in the main scanning direction and conveyance of the recording medium in the sub scanning direction. However, the present invention is also applicable to a full-line type recording apparatus that uses a recording head that extends over the entire width of the recording medium. In that case, the ink is supplied from the ink tank toward the ink jet recording head extending over the entire width direction of the recording medium, and the ink is ejected from the ink jet recording head.

  In addition, although the ink jet recording head of the present embodiment employs a system in which film boiling is generated in the ink by a heating element and foamed to eject ink droplets, the present invention is not limited to this. A recording head of a type that deforms the piezoelectric element and thereby discharges liquid inside the ink jet recording head may be applied to the recording apparatus, and another type of ink jet recording head is applied to the recording apparatus of the present invention. Also good.

  FIG. 2 is a perspective view of the ink jet recording head 19. The ink jet recording head 19 is provided with a plurality of ejection port arrays arranged along a direction orthogonal to the main scanning direction of the carriage 111. When recording is performed, the ink jet recording head 19 is mounted on the carriage 111.

  FIG. 3 is a plan view of the ejection port array provided in the ink jet recording head 19. In the present embodiment, the inkjet recording head 19 can eject ink of three colors, C (cyan), M (magenta), and Y (yellow). As shown in FIG. 3, the inkjet recording head 19 is formed with ejection port array groups C1, M1, Y, M2, and C2. The ejection port array groups C1 and C2 are ejection port array groups for cyan ink ejection, and each include two ejection port arrays La, Lb and Li, Lj. The ejection port array groups M1 and M2 are ejection port array groups for ejecting magenta ink, and each include two ejection port arrays Lc, Ld and Lg, Lh. The ejection port array group Y is an ejection port array group for discharging yellow ink, and includes two ejection port arrays Le and Lf.

  In the discharge port array group M1, a plurality of heaters 6 and discharge ports 7 are arranged at every pitch Py (1/300 inch) in each of the discharge port arrays Lc and Ld. Further, the heater 6 and the discharge port 7 of the discharge port array Lc and the heater 6 and the discharge port 7 of the discharge port array Ld are shifted by a half pitch (Py / 2 = 1/600 inch). Accordingly, it is possible to record an image with a resolution twice as high as the pitch Py of the ejection ports 7 in each of the ejection port arrays Lc and Ld. The same applies to the other ejection port array groups C1, Y, M2, and C2.

  In the inkjet recording head 19, C1, M1, Y, M2, and C2 are arranged in the order of the X direction shown in FIG. 3 orthogonal to the recording medium conveyance direction with the discharge port array group Y for discharging yellow ink as the center. Discharge port arrays are arranged. In this way, by disposing the respective ejection port arrays in the recording head, the ejection port array groups of the respective colors are disposed symmetrically about the ejection port array group Y with respect to the X direction. Since the ejection port array groups of the respective colors are arranged in line symmetry, when the inkjet recording head 19 performs reciprocal scanning in the X direction, the ejection port array groups of C1, M1, and Y are used for scanning in the forward direction. In the backward scanning, recording can be performed using the C2, M2, and Y ejection port array groups. In this way, by setting the ejection port array groups used for the forward scanning and the backward scanning, the order of the ejection port arrays used for the forward scanning and the backward scanning can be changed. Can be aligned. That is, when the print head scans in the forward and backward directions (arrows A1 and A2), yellow, cyan, and magenta inks are ejected in the same order between the forward scan and the backward scan. be able to. As a result, it is possible to suppress the occurrence of color unevenness caused by the difference in the order of the colors of the inks that are applied to the predetermined area in the bidirectional recording in which the recording is performed in both the forward scanning and the backward scanning. it can. As a result, a high-quality image can be output by recording.

  FIG. 4 is a plan view illustrating the state of the inkjet recording head 19 in FIG. 3 when the ejection port arrays Lc and Ld are enlarged and the orifice plate 3 is removed. FIG. 5 is a cross-sectional view taken along line VV of the inkjet recording head 19 of FIG. 4 with the orifice plate 3 attached.

  As shown in FIG. 5, the inkjet recording head 19 is formed by bonding the support member 1 and the substrate 2 and bonding the substrate 2 and the orifice plate 3. These configurations are the same for all the ejection port arrays in the inkjet recording head 19, and each ejection port array group is formed in a set of support member 1, substrate 2, and orifice plate 3, These members can be shared between the respective ejection port arrays. A plurality of common liquid chambers 4 corresponding to each discharge port array group are formed between the support member 1 and the substrate 2.

  The inkjet recording head 19 has a plurality of supply ports 10 that penetrate the substrate 2 and connect to the common liquid chamber 4. The orifice plate 3 is arranged by a flow path height h in a direction perpendicular to the substrate 2 (Z direction in FIG. 5) by a flow path wall 8 extending in the discharge port array direction. The substrate 2 is provided with heaters 6 as a plurality of energy generating elements arranged corresponding to the discharge ports 7 of the respective discharge port arrays. A discharge port 7 is formed at a position facing the heater 6 in the orifice plate 3.

  A plurality of liquid chambers 11 including a supply port 10 and a plurality of pressure chambers 12 including a heater 6 and a discharge port 7 are formed between the substrate 2 and the orifice plate 3 by a flow path wall 8. The liquid chamber 11 is formed facing the supply port 10, and ink is supplied from the ink tank into the liquid chamber 11 through the supply port 10. That is, the supply port 10 is an entrance for the ink supplied to the liquid chamber 11. The liquid chamber 11 is partitioned by the wall surface of the flow path wall, and is formed so that ink can be stored inside. The pressure chamber 12 is formed so as to communicate with the ejection port 7 and is formed so as to be able to store ink ejected from the ejection port 7. The heater 6 is disposed so as to face the space where the ink is stored in the pressure chamber 12. By driving the heater 6, it is possible to apply thermal energy to the ink stored in the pressure chamber 12.

  As shown in FIG. 4, the pressure chambers 12 and the liquid chambers 11 are alternately arranged in the direction in which the discharge port arrays are arranged. The liquid chamber 11 has a plurality of pressure chambers 12 adjacent to each other in the arrangement direction of the discharge port arrays, and a plurality of channel widths (FIG. 6) each having a length L2 that is shorter than L1 in the X direction. The flow paths (liquid flow paths) 9A and 9B are connected.

  FIG. 6 is an enlarged plan view showing one liquid chamber 11 among the plurality of liquid chambers 11 shown in FIG. The arrows shown in FIG. 6 indicate the flow direction of the ink supplied from the liquid chamber 11 toward the adjacent pressure chamber 12 through the plurality of flow paths 9A and 9B. As shown in FIG. 6, the positions connected to the liquid chambers 11 of the plurality of flow paths 9A and 9B in the X direction orthogonal to the arrangement direction Y of the discharge port arrays are the same as the connection positions and flow paths in the flow path 9A. It differs from the connection position on the road 9B. That is, the positions where the flow paths 9A and 9B are connected to the liquid chamber 11 along the X direction are offset. In the present embodiment, the liquid chamber 11 is arranged such that one of the flow paths 9A and 9B is located in a region on the opposite side of the other flow path across the center line in the X direction in the liquid chamber 11. Is formed. Here, the distance L3 between the position where the flow path 9A is connected to the liquid chamber 11 and the center line in the X direction in the liquid chamber 11 is the position where the flow path 9B is connected to the liquid chamber 11 and the liquid. The liquid chamber 11 is formed so as to be different from the distance L4 between the chamber 11 and the center line in the X direction.

  A position where the flow path 9A is connected to the liquid chamber 11 is C1, and a position where the flow path 9B is connected to the liquid chamber is C2. A position C1 where the flow path 9A is connected to the liquid chamber 11 and a position C2 where the flow path 9B is connected to the liquid chamber 11 are offset with respect to the X direction. Here, the position where the flow path is connected to the liquid chamber 11 refers to a position where the center line of the flow path intersects the extension line of the wall surface in the liquid chamber 11.

  Further, in both the position C1 where the flow path 9A is connected to the liquid chamber 11 and the position C2 where the flow path 9B is connected to the liquid chamber 11, the center line in the X direction of the liquid chamber 11 is Offset with respect to the X direction.

  Since the connection positions of the flow paths 9A and 9B to the liquid chamber 11 are offset, when ink is supplied from the liquid chamber 11 to the pressure chamber 12, the range in which ink is pulled from the liquid chamber 11 is wide. Therefore, even if the concentrated ink resulting from the increase in the viscosity of the ink and the increase in the density is diffused into the liquid chamber 11, the concentrated ink is efficiently removed from the liquid chamber 11 by the recovery process or the ink ejection. Can be discharged.

  FIG. 7 shows the region Z in which the concentrated ink can be discharged and the flow of ink from the supply port 10 to the flow path inside the liquid chamber 11 in the present embodiment. The flow of ink from the liquid chamber 11 to the pressure chamber 12 via the flow paths 9A and 9B is indicated by arrows. Concentrated ink generated in the pressure chamber 12 and diffusing into the liquid chamber 11 via the flow paths 9A and 9B is formed between the flow paths 9A and 9B and the liquid chamber 11 as indicated by a broken line area Z in FIG. It diffuses isotropically from the connection position.

  By disposing each of the flow paths 9A and 9B in an offset manner, the flow paths 9A and 9B are close to one wall surface in the liquid chamber 11, so that they are directed to the liquid chamber in the vicinity of the wall surface of the adjacent liquid chamber 11. The ink flow rate in the direction can be increased. Accordingly, since the ink easily flows at a position near the wall surface in the liquid chamber 11, the concentrated ink existing in the vicinity of the flow path wall is efficiently delivered to the flow paths 9A and 9B, supplied to the pressure chamber 12, and discharged. It can be discharged from the outlet 7. In addition, since the center lines of the respective flow paths 9A and 9B are not on the same straight line, ink from a wider area in the liquid chamber 11 in the X direction perpendicular to the arrangement direction Y direction of the ejection port arrays is flow paths 9A. , 9B can be reached. Accordingly, the concentrated ink diffused into the liquid chamber 11 is efficiently discharged as the ink is supplied to the pressure chamber 12.

  The concentrated ink supplied to the pressure chamber 12 is discharged from the ejection port and collected together with the surrounding ink when ink is ejected from the ejection port or recovery processing is performed. Examples of the recovery process include suction recovery in which the ink inside the discharge port 7 is sucked through the discharge port 7 while the discharge port 7 is capped. Since the concentrated ink is efficiently recovered, the amount of concentrated ink contained in the ink inside the inkjet recording head 19 can be reduced. Accordingly, it is possible to prevent the concentrated ink from being discharged from the discharge port 7 together with the ink during recording. Thereby, the influence of concentrated ink is reduced in image formation, and high-quality image formation is possible.

  Next, an enlarged plan view of the liquid chamber 11 'is shown in FIG. In FIG. 8, the connection positions to the liquid chambers along the X direction of the flow paths 9A and 9B connecting the liquid chamber 11 ′ and both of the adjacent pressure chambers 12 are the respective flow paths 9A and 9B. There is a match between. Further, the connection positions of the flow paths 9A and 9B to the liquid chamber 11 'coincide with the center line of the liquid chamber 11 in the X direction.

  Also in the comparative example, as shown in FIG. 8, the concentrated ink existing in the liquid chamber 11 ′ is centered on the connection position between the flow paths 9A and 9B and the liquid chamber 11 ′, and from there to the broken line region Y. It diffuses isotropically as shown. The flow of ink from the supply port 10 toward the flow path when the ink is supplied from the liquid chamber 11 ′ to the pressure chamber 12 by the ink discharge operation or the recovery process after the concentrated ink is diffused is indicated by an arrow. The ink flow in the liquid chamber 11 ′ is strongest on the center line in the X direction in the liquid chamber 11 ′ and becomes weaker as the distance from the center line increases. Therefore, in FIG. 8, the flow of ink toward the flow paths 9A and 9B is weak in the vicinity of the outermost wall surface in the X direction in the liquid chamber 11 ′ and the peripheral portion of the corner of the liquid chamber 11, and the flow velocity of the ink is low. Is small. For this reason, the concentrated ink diffused in that portion is difficult to be discharged into the pressure chamber 12, and the amount of discharged ink is reduced. In addition, it takes time for the ink in the vicinity of the outermost wall surface in the X direction in the liquid chamber 11 ′ and the ink around the corner of the liquid chamber 11 ′ to be discharged.

  A modification of this embodiment will be described with reference to FIG. FIG. 9 is a plan view of the liquid chamber 11 ″ in the inkjet recording head 19 according to a modification of the present embodiment. Here, the distance L5 between the position where the flow path 9A is connected to the liquid chamber 11 ″ and the center line in the X direction in the liquid chamber 11 ″ and the position where the flow path 9B is connected to the liquid chamber 11 The liquid chamber 11 ″ is formed so that the distance L6 between the liquid chamber 11 and the center line of the liquid chamber 11 is equal. As a result, as shown in FIG. 9, the liquid chambers are arranged such that the connection positions of the flow paths 9 </ b> A and 9 </ b> B and the liquid chamber 11 are arranged at 180 ° rotational symmetry with respect to the center of the liquid chamber 11 ″. 11 ″ and flow paths 9A, 9B are formed.

  In the ink jet recording head 19, by providing the flow paths 9A and 9B at positions 180 degrees rotationally symmetric, the concentrated ink is discharged when the concentrated ink is discharged from the liquid chamber 11 '' between the flow paths 9A and 9B. The degree of flow is equivalent. Therefore, for each of the liquid chambers 11 ″ arranged along the Y direction in the discharge port array, the discharge properties of the concentrated ink from the liquid chamber 11 ″ through the flow paths 9A and 9B are different. It becomes equivalent between the flow paths 9A and 9B. Therefore, when ink is ejected, the degree to which the concentrated ink is discharged from the ejection port 7 of the pressure chamber 12 is equal among the pressure chambers 12. Therefore, the ratio of the concentrated ink contained in the ink ejected from the ejection ports 7 during recording is the same among the ejection ports 7. As a result, the influence of the concentrated ink on the recorded image is equal between the pressure chambers 12, so that the density of the ink ejected for each ejection port 7 is suppressed, and a high-quality recorded image is formed. Is possible. Therefore, as shown in FIG. 9, it is desirable that the connection positions of the flow paths 9A and 9B and the liquid chamber 11 ″ be disposed at a position 180 degrees rotationally symmetric with respect to the center of the liquid chamber.

  A further modification of the first embodiment will be described with reference to FIG. FIG. 10 is a plan view of the liquid chamber 11 ″ ″ in the inkjet recording head 19 in a further modification. In a further modification, as shown in FIG. 10, the flow paths constituting the respective flow paths 9 </ b> A and 9 </ b> B on the extension line of the wall surface of the flow path wall located on the outermost side in the X direction in the liquid chamber 11 ′ ″. A liquid chamber 11 '' 'is formed so that the wall is located. In this way, the flow path walls constituting the liquid chamber 11 ′ ″ and the flow path walls of the flow paths 9A and 9B are continuously formed along the Y direction, which is the direction in which ink is supplied. It is desirable. Thus, an ink flow along the wall surface is formed in the vicinity of the wall surface of the liquid chamber 11 ′ ″ common to the flow path, and the concentrated ink located in the vicinity of the wall surface is efficiently discharged toward the pressure chamber 12. Is possible.

(Second Embodiment)
Next, an ink jet recording head according to a second embodiment of the present invention will be described. Portions similar to those of the ink jet recording head of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted. The second embodiment is different from the first embodiment in that the wall surface extending in the X direction orthogonal to the arrangement direction Y direction of the ejection port array is not horizontal to the X axis but intersects the X axis. FIG. 11 is an enlarged plan view showing the liquid chamber 11 ″ ″ of the ink jet recording head according to the second embodiment.

  As shown in FIG. 11, in the liquid chamber 11 of the ink jet recording head 19, the connection position C3 of the flow path 9A and the liquid chamber 11 ″ ″, the extension line at the center of the flow path 9A, and the liquid chamber 11 ′ ″. The distance L7 between the position C4 where the wall surface of 'intersects is shorter than the width L8 of the liquid chamber 11. Further, the distance L9 between the connection position C5 of the flow path 9B and the liquid chamber 11 '' '' and the position C6 where the extension line at the center of the flow path 9B intersects the wall surface of the liquid chamber 11 '' '' is , Shorter than the width L8 of the liquid chamber 11 '' ''. Here, the width of the liquid chamber 11 ″ ″ refers to the distance between the positions closest to both of the adjacent pressure chambers 12 in the liquid chamber 11 with respect to the Y direction which is the arrangement direction of the discharge port arrays. And That is, in the present embodiment, the width of the liquid chamber 11 ″ ″ refers to the distance between the wall surfaces located at the furthest positions in the liquid chamber 11 ″ ″ along the Y direction. To do.

  In the present embodiment, the flow paths 9A and 9B with respect to the center line in the X direction in the liquid chamber 11 '' '' among the wall surfaces at the end in the arrangement direction Y direction of the discharge port array in the liquid chamber 11 '' ''. The liquid chamber 11 ″ ″ is formed so that the wall surface on the side where the liquid crystal does not exist is inclined with respect to the X axis. Therefore, at the position where the extension of the center line of the flow paths 9A and 9B connected to the liquid chamber 11 '' '' intersects the end of the opposite liquid chamber 11 '' '' in the Y direction, the liquid chamber 11 The wall surface of the end in the Y direction of '' '' goes inside. The distance between the connection position of each flow path 9A, 9B and the liquid chamber 11 and the wall surface at the end in the Y direction of the liquid chamber facing the flow paths 9A, 9B is compared to the liquid chamber of the first embodiment. It is getting shorter. Since the wall surface at the end in the Y direction of the liquid chamber 11 ″ ″ facing the flow paths 9A and 9B is close to the flow paths 9A and 9B, a stronger ink flow is generated near the wall surfaces. .

  Further, since the wall surface at the end in the Y direction of the liquid chamber 11 ″ ″ facing the flow paths 9A and 9B is located inside, the corner portion of the liquid chamber 11 ″ ″ is the flow path wall. 8 is buried. Therefore, since the corners in the space in the liquid chamber 11 ″ ″ are taken, the change in the ink flow path becomes gentle, and the resistance of the ink flow from the supply port 10 toward the flow paths 9 </ b> A and 9 </ b> B is reduced. Further, since the corner portion in the space inside the liquid chamber 11 ″ ″ ″ is taken, it is possible to prevent the concentrated ink from remaining in the stagnation of the ink flow at the corner. Accordingly, the concentrated ink in the liquid chamber 11 '' '' can be more efficiently discharged, and it is possible to suppress the discharge of the concentrated ink together with the normal density ink from the discharge port during recording. it can. This makes it possible to obtain a high-quality recorded image by recording.

  Next, a modification of the second embodiment will be described with reference to FIG. FIG. 12 is a plan view showing the liquid chamber 11 ″ ″ ″ ″ of the ink jet recording head in the second embodiment. As shown in FIG. 12, in the modification of the second embodiment, the liquid chamber 11 ′ ″ ″ is changed so that the corner of the space inside the liquid chamber 11 ′ ″ ″ changes gently. Is formed. That is, the liquid chamber 11 ″ ″ ″ is formed so that the wall surface is gently bent at the portion where the extending direction of the wall surface defining the liquid chamber 11 ″ ″ ″ changes. Since the corners of the liquid chamber 11 '' '' 'are gently formed and the shape of the wall surface is streamlined, it is possible to suppress the occurrence of a stagnation part due to the ink flow, and the concentrated ink is supplied to the liquid chamber 11'. Residue inside '' '' is suppressed. In addition, since the resistance to ink flow is reduced, when ink is supplied from the liquid chamber 11 ′ ″ ″ to the pressure chamber 12, the ink is supplied more efficiently, and the liquid chamber 11 ′ ″ ″. The concentrated ink inside is also efficiently discharged and collected.

  Next, a further modification of the second embodiment will be described with reference to FIG. FIG. 13 is a plan view showing a liquid chamber 11 ″ ″ ″ ″ in an ink jet recording head according to a further modification of the second embodiment. As shown in FIG. 13, on the extension line of the wall surface of the channel wall located in the outermost side in the X direction in the liquid chamber 11 '' '' '', the channel walls constituting the respective channels 9A and 9B are provided. A liquid chamber 11 '' '' '' is formed so as to be positioned. FIG. 14 is an enlarged plan view showing a part of the pressure chambers 12 and the liquid chambers 11 ″ ″ ″ in the ejection port array in the ink jet recording head of a further modification of the second embodiment. is there. FIG. 14 shows a plan view of the ink jet recording head with the orifice plate 3 removed. In this way, the flow path walls constituting the liquid chamber 11 '' '' '' and the flow path walls of the flow paths 9A and 9B are continuously formed along the Y direction, which is the direction in which ink is supplied. It is desirable that Accordingly, an ink flow along the wall surface is formed in the vicinity of the wall surface of the liquid chamber common to the flow path, and the concentrated ink located in the vicinity of the wall surface can be efficiently discharged toward the pressure chamber 12. .

(Third embodiment)
Next, an ink jet recording head according to a third embodiment of the present invention will be described. An ink jet recording head according to a third embodiment of the present invention will be described with reference to FIGS. In addition, about the part similar to 1st Embodiment and 2nd Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted. In the ink jet recording head of the third embodiment, the flow paths 9A and 9B connected to the liquid chamber 11 ′ ″ ″ ″ are formed to be inclined with respect to the Y direction in which the ejection port arrays are arranged. This is different from the ink jet recording heads of the first and second embodiments.

  FIG. 15 is a plan view of one liquid chamber 11 ″ ″ ″ ″ ″ in the discharge port array. FIG. 15 shows a plan view of the ink jet recording head with the orifice plate 3 removed.

  As shown in FIG. 15, the center line along the supply direction in which ink is supplied in each of the flow paths 9 </ b> A and 9 </ b> B connecting the liquid chamber 11 ″ ″ ″ ″ and the pressure chamber 12. Inclined with respect to the arrangement direction Y in which the discharge port arrays are arranged. Here, m is a line connecting the centers of the discharge ports 7 and the supply ports 10 in the discharge port array, and the center lines of the flow paths 9A and 9B connected to the liquid chambers 11 '' '' '' '. Are n1 and n2. At this time, the center lines n1 and n2 of the flow paths 9A and 9B intersect with a line m connecting the centers of the discharge ports 7 in the discharge port array. That is, the extending direction of the flow paths 9A and 9B intersects with the arrangement direction in which the discharge port arrays are arranged.

  Thus, since the flow paths 9A and 9B are formed to be inclined with respect to the arrangement direction Y of the discharge port arrays, the flow paths 9A and 9B are formed to extend in the same direction as the arrangement direction Y of the discharge port arrays. Compared with the case where it has, the length of flow-path 9A, 9B can be lengthened. Since the lengths of the flow paths 9A and 9B between the pressure chamber 12 and the liquid chamber 11 ′ ″ ″ ″ are increased, even if the concentrated ink generated in the pressure chamber 12 is diffused in the ink, The amount of concentrated ink that reaches the liquid chamber 11 '' '' '' 'can be reduced.

  In addition, since the flow paths 9A and 9B are formed to be inclined with respect to the arrangement direction Y of the ejection port array, the length of the flow paths 9A and 9B is increased, so that the concentrated ink is diffused into the pressure chamber 12. The arrangement of the pressure chambers 12 can be maintained at a high density while being suppressed to a low level. Therefore, since the arrangement of the discharge ports 7 is maintained at a high density, the number of dots that can be discharged per unit area can be increased, and the resolution can be improved in a recorded image recorded by the ink jet recording head. Thereby, the quality of the recording image recorded by the ink discharge from the ink jet recording head can be improved.

  FIG. 16 is a plan view of a part of the two ejection port arrays in the ink jet recording head according to the third embodiment. FIG. 16 is a plan view of the ink jet recording head with the orifice plate 3 removed. As shown in FIG. 16, the flow paths 9 </ b> A and 9 </ b> B are inclined with respect to the arrangement direction Y of the discharge port arrays in any of the two discharge port arrays. Therefore, the arrangement of the discharge ports 7 can be maintained at a high density in any of the discharge port arrays. Therefore, it is possible to further improve the quality of a recorded image obtained by ejecting ink from the ink jet recording head.

(Other examples)
In the above embodiment, only in the second embodiment, the wall surface is gently bent at the portion where the extending direction of the wall surface defining the liquid chamber changes, but the present invention is not limited to this. Also in the liquid chambers of the first embodiment and the third embodiment, the wall surface may be gently bent at the portion where the extending direction of the wall surface defining the liquid chamber changes.

  In the above embodiment, only in the third embodiment, the flow path is inclined with respect to the arrangement direction Y of the discharge port arrays, but the present invention is not limited to this. Also in the liquid chambers of the first embodiment and the second embodiment, the flow path may be formed to be inclined with respect to the arrangement direction Y of the discharge port arrays. At that time, the wall surface may be gently bent at the portion where the extending direction of the wall surface defining the liquid chamber changes, or the flow path wall of the flow channel is continuous with the extension line of the flow channel wall in the liquid chamber. It is good also as being formed. Thus, the ink jet recording head may be configured by other combinations of the embodiments.

  In the present specification, “recording” is used not only for forming significant information such as characters and graphics but also for any case. It also represents the case where images, patterns, patterns, etc. are widely formed on a recording medium, or the recording medium is processed, regardless of whether it is manifested so that it can be perceived by human eyes. And

  The “recording device” includes a device having a printing function such as a printer, a printer multifunction device, a copying machine, and a facsimile device, and a manufacturing device that manufactures an article using an ink jet technique.

  “Recording medium” means not only paper used in general recording apparatuses but also a wide range of materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. Shall.

  Furthermore, “ink” (sometimes referred to as “liquid”) should be interpreted widely as in the definition of “recording”. By being applied on the recording medium, it can be used for formation of images, patterns, patterns, etc., processing of the recording medium, or ink processing (for example, solidification or insolubilization of the colorant in the ink applied to the recording medium). It shall represent a liquid.

6 Heater 7 Discharge port 9A, 9B Flow path 11 Liquid chamber 12 Pressure chamber

Claims (9)

A pressure chamber comprising an energy generating element capable of storing liquid therein and applying energy to the stored liquid; and a discharge port for discharging the liquid to which energy is applied by the energy generating element;
A supply port for supplying liquid to the pressure chamber;
A liquid chamber capable of storing liquid to be supplied to the pressure chamber through the supply port;
A liquid channel that is connected between the pressure chamber and the liquid chamber and guides the liquid from the liquid chamber to the pressure chamber;
A plurality of the discharge ports are disposed along the first direction, and the pressure chambers and the liquid chambers are alternately disposed,
The liquid channel extending from each of the two pressure chambers sandwiching the liquid chamber is connected to the liquid chamber sandwiched between the pressure chambers,
The two discharge positions where the liquid chamber and the two liquid flow paths are connected are offset with respect to a second direction intersecting the first direction, respectively.   The two connection positions where the liquid chamber and the two liquid flow paths are connected are located on opposite sides of a center line with respect to the second direction at the supply port, respectively. The liquid discharge head according to claim 1.   The two connection positions where the liquid chamber and the two liquid flow paths are connected are respectively symmetrical with respect to a center line of the supply port with respect to the second direction. Item 3. The liquid discharge head according to Item 1 or 2.   4. The liquid ejection head according to claim 1, wherein the liquid chamber has a rotational symmetry of 180 degrees with respect to a center of the liquid chamber. 5.   The wall surface facing the connection position in the liquid chamber is formed so as to enter inward from the position of the wall surface positioned on the outermost side in the liquid chamber with respect to the first direction. The liquid discharge head according to any one of 1 to 4.   The flow path wall located on the outermost side in the second direction in the liquid chamber extends in the first direction, and on the extension line of the flow path wall located on the outermost side in the second direction, The liquid discharge head according to claim 1, wherein a flow path wall of the liquid flow path is formed continuously.   7. The liquid discharge head according to claim 1, wherein the wall surface is gently bent at a portion where the extending direction of the wall surface defining the liquid chamber is changed.   The liquid discharge head according to claim 1, wherein a direction in which the liquid channel extends intersects the first direction. A pressure chamber comprising an energy generating element capable of storing liquid therein and applying energy to the stored liquid; and a discharge port for discharging the liquid to which energy is applied by the energy generating element;
A supply port for supplying liquid to the pressure chamber;
A liquid chamber capable of storing liquid to be supplied to the pressure chamber through the supply port;
A liquid discharge head that is connected between the pressure chamber and the liquid chamber and guides the liquid from the liquid chamber to the pressure chamber, and the liquid is discharged from the discharge port of the liquid discharge head. A liquid ejection device for ejecting a liquid onto a medium,
A plurality of the discharge ports are disposed along the first direction, and the pressure chambers and the liquid chambers are alternately disposed,
The liquid channel extending from each of the two pressure chambers sandwiching the liquid chamber is connected to the liquid chamber sandwiched between the pressure chambers,
The liquid ejecting apparatus according to claim 1, wherein two connection positions where the liquid chamber and the two liquid flow paths are connected are offset with respect to a second direction intersecting the first direction.

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