Liquid ejection head
10744778 ยท 2020-08-18
Assignee
Inventors
Cpc classification
B41J2002/14467
PERFORMING OPERATIONS; TRANSPORTING
International classification
B41J2/14
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A liquid ejection head includes a plurality of liquid chambers each including an energy generating element that generates energy for ejecting a liquid, an ejection opening that ejects the liquid, and a liquid supply opening that supplies the liquid, the liquid flowing in a first direction in the plurality of liquid chambers, and the plurality of liquid chambers being arranged in a second direction that intersects the first direction, and a plurality of first side walls that extend in the first direction and that form walls on both sides of the plurality of liquid chambers. In the liquid ejection head, each of the plurality of first side walls includes a fragmenting portion that fragments each of the plurality of first side walls in the first direction.
Claims
1. A liquid ejection head, comprising: a plurality of liquid chambers; two resistive elements provided inside each of the plurality of liquid chambers and configured to be driven to eject a liquid; ejection openings provided correspondingly opposed to the two resistive elements; one liquid supply opening provided for each of the plurality of liquid chambers and configured to supply the liquid to each of the resistive elements; and a partition wall provided for each of the plurality of liquid chambers for partitioning between the two resistive elements, without reaching the liquid supply opening, wherein the plurality of liquid chambers is arranged in a second direction that intersects with a first direction in which the liquid supplied from the liquid supply opening flows toward the resistive elements, wherein the plurality of liquid chambers has a plurality of first sidewalls such that walls extending in the first direction on both sides of each of the plurality of liquid chambers are constituted by corresponding two of the plurality of first sidewalls, wherein each of the plurality of first sidewalls is shared by adjacent two of the liquid chambers that are adjacent to each other, wherein each of the plurality of first sidewalls has such a structure that a slit or a part of a slit that communicates adjacent two of the liquid chambers that are adjacent to each other via each of the plurality of first sidewalls is connected by a connecting member, wherein a second sidewall is provided such that a dummy liquid chamber is formed between the second sidewall and, among the plurality of first sidewalls, a first sidewall that is located at an end in the second direction, and wherein two elements that are not driven, openings formed at positions facing each of the two elements that are not driven, and one liquid supply opening configured to supply the liquid toward the elements that are not driven, are provided inside the dummy liquid chamber.
2. The liquid ejection head according to claim 1, wherein a partition wall for partitioning between the two elements, without reaching the liquid supply opening, is provided inside the dummy liquid chamber, wherein the element located closer to the first sidewall is able to be driven, and wherein the element located closer to the second sidewall is not driven.
3. The liquid ejection head according to claim 1, wherein the structure that the slit or the part of the slit is connected by the connecting member is provided in each of the plurality of first sidewalls is provided on a straight line extending in the second direction.
4. The liquid ejection head according to claim 1, wherein each of the plurality of liquid chambers, and the dummy liquid chamber, has a second supply opening or a liquid correction opening at an opposite side inside said chamber, with the elements located therebetween.
5. The liquid ejection head according to claim 4, wherein the liquid inside the liquid chamber is circulated to and from outside of the liquid chamber using the liquid correction opening and the first supply opening.
6. The liquid ejection head according to claim 4, wherein each of the plurality of first side walls includes a structure that two slits or parts of two slits are connected by a connecting member, the two slits or a part of the two slits being provided on both sides of the ejection openings in the first direction at equidistant positions with respect to the ejection openings.
7. The liquid ejection head according to claim 1, wherein two third sidewalls for compartmentalization into the plurality of liquid chambers and the dummy liquid chamber together with the first sidewalls and the second sidewall are provided such that the first sidewalls, the second sidewall, and the partition walls are configured integrally with the third side walls.
8. The liquid ejection head according to claim 1, wherein two third sidewalls for compartmentalization into the plurality of liquid chambers and the dummy liquid chamber together with the first sidewalls and the second sidewall are provided such that the first sidewalls and the partition walls are separated from the third sidewalls and such that the second sidewall is configured integrally with the third side walls.
9. The liquid ejection head according to claim 1, wherein 0.7PDP holds true, where P is half a length of each of the partition walls in the first direction, and D is a distance in the first direction between a center of the ejection opening and the fragmenting portion.
10. The liquid ejection head according to claim 1, wherein a filter is provided between the first supply opening and the element inside the liquid chamber.
11. The liquid ejection head according to claim 4, wherein a filter is provided between the first supply opening and the element inside the liquid chamber, and another filter is provided between the second supply opening or the liquid collection opening and the resistive element.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE EMBODIMENTS
(10) Hereinafter, some embodiments of the present disclosure will be described with reference to the drawings. While the liquid ejection heads of the exemplary embodiments described below adopt a thermal method that ejects ink by creating a bubble with a heating element, the present disclosure can be used in liquid ejection heads adopting a piezoelectric method and other various liquid ejection methods. While the liquid ejection heads of the exemplary embodiments eject ink, the present disclosure can be used in liquid ejection heads that eject a liquid other than ink. In the exemplary embodiments below, a first direction X is a direction in which ink inside liquid chambers flows, or a direction in which first side walls extend, and a second direction Y is a direction in which the plurality of liquid chambers are arranged. In each of the exemplary embodiments, while the second direction Y is orthogonal to the first direction X, the second direction Y does not have to be orthogonal to the first direction X as long as the second direction Y intersects the first direction X.
First Exemplary Embodiment
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(12) A liquid ejection head 101 includes a substrate 1 and an ejection opening forming member 4 formed on the substrate 1. The substrate 1 is formed of silicon, and the ejection opening forming member 4 is formed of resin. In the present exemplary embodiment, an ejection opening forming member that is formed of resin and that is easily affected by heat and swelling is described; however, the present disclosure is not limited to such an ejection opening forming member. The present disclosure can be applied to an ejection opening forming member formed of an inorganic material, such as silicone, or a metal material, such as stainless steel. A plurality of energy generating elements 2 that generate energy for ejecting a liquid are formed in the substrate 1. Each energy generating element 2 includes a heat generating element that generates heat upon application of a current. A plurality of liquid supply openings 3a that supply ink, and a plurality of liquid collect openings 3b that collect ink are formed in the substrate 1. The liquid collect openings 3b are provided on the opposite side of the liquid supply openings 3a with respect to the energy generating elements 2. The liquid supply openings 3a and the liquid collect openings 3b are through holes that penetrate through the substrate 1 in the thickness direction and are connected to a common liquid flow path (not shown). The energy generating elements 2, the liquid supply openings 3a, and the liquid collect openings 3b are each arranged in the second direction Y.
(13) The ejection opening forming member 4 includes a plurality of first side walls 11 that extend in the first direction X, two third side walls 13 that are adhered to the first side walls 11 and that extend in the second direction Y, and a top plate 14 that is adhered to the first and third side walls 11 and 13. The plurality of first side walls 11 are arranged in the second direction Y. A plurality of ejection openings 8 that oppose the energy generating elements 2 and that eject ink are formed in the top plate 14. A plurality of liquid chambers 7 that each include the energy generating element 2, the liquid supply opening 3a, and the liquid collect opening 3b are formed between the ejection opening forming member 4 and the substrate 1 with the first side walls 11, the third side walls 13, and the top plate 14. The plurality of liquid chambers 7 are arranged in the second direction Y. Each liquid chamber 7 is defined by two first side walls 11 that are adjacent to each other, and two third side walls 13. In other words, walls extending in the first direction X on both sides of each liquid chamber 7 are formed by two first side walls 11 with the liquid chamber 7 in between, and walls extending in the second direction Y on both sides of each liquid chamber 7 are formed by two third side walls 13 with the liquid chamber 7 in between. The liquid chambers 7 are each formed of a pressure chamber 6 in which the energy generating element 2 is formed, a liquid supply passage 5a in which the liquid supply opening 3a opens, and a liquid collect passage 5b in which the liquid collect opening 3b opens. The plurality of liquid chambers 7 are formed in a symmetrical manner with respect to a line that passes through the centers of the energy generating elements 2, or the ejection openings 8, and that extends in the second direction Y, and the liquid supply openings 3a and the liquid collect openings 3b are, with respect each other, formed symmetrical to the line. Each pressure chamber 6 is an area that is interposed between two of the corresponding first side walls 11 and where the corresponding energy generating element 2 is provided, and in a broad sense, is an area to where a pressure is applied when the corresponding energy generating element 2 is driven.
(14) Ink in each plurality of liquid chamber 7 flows in the first direction X. In other words, ink flows into the liquid supply passage 5a from the liquid supply opening 3a, passes through the pressure chamber 6 and the liquid collect passage 5b, and flows out from the liquid collect opening 3b. Accordingly, ink in which moisture has evaporated and that has become thickened does not easily become stagnated in the vicinity of the ejection opening 8 and, accordingly, leads to an improvement in image quality. Second liquid supply openings may be provided in place of the liquid collect openings 3b. In such a case, since ink is supplied to the pressure chamber 6 from two directions, the ink supplying ability improves such that high-speed printing is facilitated.
(15) While each first side wall 11 is shared by adjacent liquid chambers 7, each liquid chamber 7 may be provided with separate first side walls 11. In such a case, the liquid chamber 7 and a space in which no ink flows are arranged alternately.
(16) The top plate 14 is a flat plate that extends substantially parallel to the substrate 1 and is adhered to or integral to the plurality of first side walls 11 and the two third side walls 13. A plurality of through holes 10 penetrate the top plate 14, and ejection openings 8 are formed at the ends of the through holes 10 on the side opposite to the plurality of liquid chambers 7, in other words, at the ends of the through holes 10 that oppose the recording medium. The ejection openings 8 oppose the energy generating elements 2 in a direction perpendicular to the surface of the substrate 1 that opposes the ejection opening forming member 4. By driving the energy generating elements 2, bubbles are formed inside the ink and with the pressure created during the formation of the bubbles, the ink is pushed out from the through holes 10 and is ejected from the ejection openings 8.
(17) The ejection opening forming member 4 includes two second side walls 12 that are positioned at the end portions thereof in the second direction Y and that are connected to the first side walls 11. The second side walls 12 are also connected to the third side walls 13. The second side walls 12 and the first side walls 11 at the end portions form dummy liquid chambers 17. The liquid supply openings 3a and the liquid collect openings 3b are also formed in the dummy liquid chambers 17 through which ink flows in and out. Since the second side walls 12 extends in a continuous manner and is not provided with any fragmenting portions 9 described later, leaking of ink from the dummy liquid chambers 17 to the outside of the liquid ejection head 101 is prevented. The dummy liquid chambers 17 are provided with dummy elements 22 that are not driven; accordingly, the dummy liquid chambers 17 do not contribute to the ejection of ink. Alternatively, the energy generating elements 2 or the dummy elements 22 do not have to be provided in the dummy liquid chambers 17.
(18) Each of the first side walls 11 includes two fragmenting portions 9 that fragment the first side wall 11 in the first direction X. A fragmenting portion 9 is provided on each side of the ejection opening 8 in the first direction X at equidistant positions with respect to the ejection opening 8. Although each fragmenting portion 9 has a slit-like shape, the shape is not limited to any shape in particular. Each fragmenting portion 9 may be, for example, a linear slit 9a illustrated in
(19) In a liquid ejection head, the configuration of first side walls 11a at the end portions and the configuration of second side walls 11a that are the next side walls inside the first side walls 11a are different, and when ink is filled inside the liquid chamber 7 and when the ejection opening forming member 4 becomes deformed due to swelling, as illustrated in
(20) In the present exemplary embodiment, as described above, the dummy liquid chambers 17 are provided outside the liquid chambers 7 at the end portions. Accordingly, the fragmenting portions 9 can be provided in the first side walls 11 at the end portions in the second direction Y in a similar manner to the other first side walls 11. Since the two first side walls 11 of all the ejection openings 8 can be configured in the same manner, the above problem is resolved and the inclination of all of the ejection openings 8 can be reduced.
(21) The fragmenting portions 9 are provided at the same positions in all of the first side walls 11. In other words, each fragmenting portion 9 provided in each first side wall 11 is provided on a straight line extending in the second direction Y in
(22) In the exemplary embodiment illustrated in
Second Exemplary Embodiment
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(24) In the present exemplary embodiment as well, the deformation of the ejection openings 8, in particular, the inclination of the ejection openings 8 in the second direction Y, due to swelling of the ejection opening forming member 4 can be suppressed with the fragmenting portions 9. The effect of suppressing the deformation of the ejection openings 8 becomes larger as the fragmenting portions 9 are disposed closer to the ejection openings 8, and becomes smaller as the fragmenting portions 9 are disposed farther away from the ejection openings 8. Similar to the first exemplary embodiment, by forming each fragmenting portion 9 so that the opening width S is 10 m or smaller and, preferably, 5 m or smaller, while suppressing deformation of the ejection openings 8, the liquid ejection head 201 that can reduce the effect that the crosstalk has on the adjacent ejection opening 8 can be obtained. In the present exemplary embodiment, since the third side walls 13 are in the vicinity of the ejection openings 8, it is difficult to suppress the deformation of the ejection openings 8 in the first direction X. However, while it is difficult to correct the ink landing positions in the second direction Y, the ink landing positions in the first direction X can be corrected easily by adjustment of the print conditions and the like.
(25) As illustrated in
Third Exemplary Embodiment
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(27) The plurality of energy generating elements 2 in each liquid chamber 7 is separated from each other by a partition wall 15 that extends in the first direction X. The partition wall 15 is disposed in each of the pressure chamber 6 and is not disposed in the liquid supply openings 3a and the liquid collect openings 3b. Accordingly, the partition wall 15 is separated from the third side walls 13. The partition walls 15 are formed in a symmetrical manner with respect to a line that passes through the centers of the energy generating elements 2, or the ejection openings 8, and that extends in the second direction Y. In the present exemplary embodiment, since there is a first side wall 11 on one side of each ejection opening 8 and there is a partition wall 15 on the other side of each ejection opening 8, a portion around each ejection opening 8 is more asymmetric compared with the first exemplary embodiment.
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(29) In
Fourth Exemplary Embodiment
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(31) In the present exemplary embodiment as well, the deformation of the ejection openings 8, in particular, the inclination of the ejection openings 8 in the second direction Y, due to swelling of the ejection opening forming member 4 can be suppressed with the fragmenting portions 9. The effect of suppressing the deformation of the ejection openings 8 becomes larger as the fragmenting portions 9 are disposed closer to the ejection openings 8, and becomes smaller as the fragmenting portions 9 are disposed farther away from the ejection openings 8. Similar to the first exemplary embodiment, by forming each fragmenting portion 9 so that the opening width S is 10 m or smaller and, preferably, 5 m or smaller, while suppressing deformation of the ejection openings 8, the liquid ejection head 401 that can reduce the effect that the crosstalk has on the adjacent ejection opening 8 can be obtained. In the present exemplary embodiment, since the third side walls 13 are in the vicinity of the ejection openings 8, compared with the first exemplary embodiment, it is difficult to suppress the deformation of the ejection openings 8 in the first direction X. However, while it is difficult to correct the ink landing positions in the second direction Y, the ink landing positions in the first direction X can be corrected easily by adjustment of the print conditions and the like.
(32) As illustrated in
(33) As described above, while some of the exemplary embodiments of the present disclosure have been described, some or all of the fragmenting portions 9 of the present disclosure may be replaced with a section reducing portion that is a portion in which the section vertical to the first direction X has been scaled down. Regarding the section reducing portion, a linear section reducing portion 19a illustrated in
(34) The present disclosure is capable of providing a liquid ejection head that is capable of suppressing variation in the deformation of the plurality of ejection openings due to swelling.
(35) While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure 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.