Patent Grant
10870274
This application is a U.S. Nationalization of PCT Application Number PCT/JP2017/043977, filed on Dec. 7, 2017, which claims priority to JP Patent Application No. 2016-2419118, filed Dec. 22, 2016, and JP Patent Application No. 2017-026372, filed Feb. 15, 2017, the entireties of which are incorporated herein by reference.
The present invention relates to a technology of ejecting a liquid such as ink.
In the related, there is proposed a liquid ejecting head that ejects a liquid such as ink from a plurality of nozzles. For example, PTL 1 discloses a liquid ejecting head having a stacking structure in which a flow channel forming substrate is disposed on a front surface of a communication plate on one side, and a nozzle plate is disposed on a front surface thereof on the other side. The flow channel forming substrate is provided with a pressure generating chamber that is filled with a liquid which is supplied from a common liquid chamber (reservoir), and the nozzle plate is provided with a nozzle. The pressure generating chamber and the nozzle communicate with each other via a communication channel formed in the communication plate. The front surface of the communication plate, on which the nozzle plate is disposed, is provided with a circulation flow channel, which communicates with the common liquid chamber, and a groove-shaped circulating communication channel through which the communication channel and the circulation flow channel communicate with each other. According to the configuration described above, it is possible to circulate a liquid inside the communication channel to the common liquid chamber via the circulating communication channel and the circulation flow channel.
PTL 1: Japanese Unexamined Patent Application Publication No. 2012-143948
In a technology in PTL 1, the circulating communication channel is formed in the communication plate, and thus it is difficult to sufficiently ensure mechanical strength of the communication plate. With consideration for such circumstances described above, one of objects of a preferred aspect of the present invention is to limit a reduction in mechanical strength due to a liquid chamber provided to circulate a liquid.
In order to solve such a problem described above, according to a preferred aspect (aspect A1) of the present invention, there is provided a liquid ejecting head including: a nozzle plate provided with a nozzle; a flow channel forming unit provided with a pressure chamber to which a liquid is supplied, a communication channel through which the nozzle and the pressure chamber communicate with each other, and a circulating liquid chamber communicating with the communication channel; and a pressure generating unit that generates a pressure change in the pressure chamber. A height at a first location in the circulating liquid chamber is larger than a height at a second location on a side of the communication channel when viewed from the first location. In the aspect described above, since the height at the first location in the circulating liquid chamber is larger than the height at the second location on the side of the communication channel when viewed from the first location, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit than in a configuration in which the entire circulating liquid chamber has the same height as that at the first location.
In a preferred example (aspect A2) according to the aspect A1, the circulating liquid chamber may not overlap the pressure chamber in a plan view. In the aspect described above, since the circulating liquid chamber does not overlap the pressure chamber, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit than in a configuration in which the circulating liquid chamber overlaps the pressure chamber.
In a preferred example (aspect A3) according to the aspect A1 or A2, a maximum value of the height of the circulating liquid chamber may be smaller than a flow channel length of the communication channel. In the aspect described above, the maximum value of the height of the circulating liquid chamber is smaller than the flow channel length of the communication channel. Hence, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit than in a configuration in which the maximum value of the height of the circulating liquid chamber is equal to or larger than the flow channel length of the communication channel.
In a preferred example (aspect A4) according to the aspect A1 or A2, the flow channel forming unit may have a first flow channel substrate provided with the communication channel and the circulating liquid chamber and a second flow channel substrate provided with the pressure chamber, and a maximum value of the height of the circulating liquid chamber may be equal to or smaller than a half of a thickness of the first flow channel substrate. In the aspect described above, the maximum value of the height of the circulating liquid chamber is equal to or smaller than a half of the thickness of the first flow channel substrate. Hence, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit than in a configuration in which the maximum value of the height of the circulating liquid chamber is larger than a half of the thickness of the first flow channel substrate.
In a preferred example (aspect A5) according to any one of the aspects A1 to A4, a maximum value of the height of the circulating liquid chamber may be smaller than a width of the circulating liquid chamber. In the aspect described above, the maximum value of the height of the circulating liquid chamber is smaller than the width of the circulating liquid chamber. Hence, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit than in a configuration in which the maximum value of the height of the circulating liquid chamber is larger than the width.
In a preferred example (aspect A6) according to any one of the aspects A1 to A5, the height of the circulating liquid chamber may monotonically decrease from a position at which the height is maximum to an end portion of the circulating liquid chamber in a width direction. In the aspect described above, since the height monotonically decreases from the position, at which the circulating liquid chamber has the maximum height, to the end portion in the width direction, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit.
In a preferred example (aspect A7) according to any one of the aspects A1 to A6, the circulating liquid chamber may have an upper surface provided with a plurality of grooves extending into a curved shape in a plan view. In the aspect described above, since the circulating liquid chamber has the upper surface provided with the plurality of curved grooves, it is possible to adjust a direction, in which a liquid flows in the circulating liquid chamber, by the plurality of grooves.
In a preferred example (aspect A8) according to the aspect A7, the circulating liquid chamber may elongate in a first direction, and the plurality of grooves may have a convex shape on a first side in the first direction in a plan view. In the aspect described above, the plurality of grooves have the convex shape on the first side in the first direction. Hence, it is possible to easily cause the liquid flowing into the circulating liquid chamber to flow toward a second side opposite to the first side.
In a preferred example (aspect A9) according to the aspect A7, the nozzle plate may be provided with a first nozzle and a second nozzle as the nozzle, and the flow channel forming unit may be provided with the pressure chamber and the communication channel corresponding to the first nozzle, the pressure chamber and the communication channel corresponding to the second nozzle, and the circulating liquid chamber that is positioned between the communication channel corresponding to the first nozzle and the communication channel corresponding to the second nozzle and that elongates in the first direction. The grooves formed in a region of the upper surface of the circulating liquid chamber on a side of the first nozzle may have a convex shape on a first side in the first direction, and the grooves formed in a region on a side of the second nozzle may have a convex shape on a second side opposite to the first side in a plan view. In the aspect described above, an advantage is achieved in that it is easy to cause the liquid flowing into the circulating liquid chamber from the communication channel corresponding to the first nozzle to flow toward the second side in the first direction, and it is easy to cause the liquid flowing into the circulating liquid chamber from the communication channel corresponding to the second nozzle to flow toward the first side in the first direction.
In a preferred example (aspect A10) according to the aspect A7, the nozzle plate may be provided with a first nozzle and a second nozzle as the nozzle, and the flow channel forming unit may be provided with the pressure chamber and the communication channel corresponding to the first nozzle, the pressure chamber and the communication channel corresponding to the second nozzle, and the circulating liquid chamber that is positioned between the communication channel corresponding to the first nozzle and the communication channel corresponding to the second nozzle and that elongates in the first direction. The grooves formed in a region of the upper surface of the circulating liquid chamber on a side of the first nozzle and the grooves formed in a region on a side of the second nozzle may have a convex shape on a first side in the first direction in a plan view. In the aspect described above, an advantage is achieved in that it is easy to cause both the liquid flowing into the circulating liquid chamber from the communication channel corresponding to the first nozzle and the liquid flowing into the circulating liquid chamber from the communication channel corresponding to the second nozzle to flow toward the second side opposite to the first side.
In a preferred example (aspect A11) according to the aspect A7, the nozzle plate may be provided with a plurality of nozzles arranged in the first direction, and the flow channel forming unit may be provided with the pressure chamber and the communication channel corresponding to each of the plurality of nozzles and the circulating liquid chamber elongating in the first direction. Grooves of the plurality of grooves which are positioned on a first side in the first direction may have a convex shape on a second side opposite to the first side in a plan view, and grooves of the plurality of grooves on the second side in the first direction may have a convex shape on the first side in a plan view. In the aspect described above, an advantage is achieved in that it is easy to cause the liquid flowing into the circulating liquid chamber from the nozzle positioned on the first side in the first direction to flow toward the first side, and it is easy to cause the liquid flowing into the circulating liquid chamber from the nozzle positioned on the second side in the first direction to flow toward the second side.
In a preferred example (aspect A12) according to any one of the aspects A1 to A11, the flow channel forming unit may be provided with a first circulating liquid chamber and a second circulating liquid chamber as the circulating liquid chamber, which are positioned on opposite sides of each other with the communication channel interposed therebetween and which communicate with the communication channel. In the aspect described above, since the first circulating liquid chamber and the second circulating liquid chamber are positioned on opposite sides of each other with the communication channel interposed therebetween, it is possible to more increase a circulation amount of the liquid than in a configuration in which only one of the first circulating liquid chamber and the second circulating liquid chamber is provided.
In a preferred example (aspect A13) according to the aspect A12, the first circulating liquid chamber may not overlap the pressure chamber in a plan view, but the second circulating liquid chamber may overlap the pressure chamber in a plan view. In the aspect described above, since the first circulating liquid chamber does not overlap the pressure chamber, but the second circulating liquid chamber overlaps the pressure chamber, an advantage is achieved in that it is easier to maintain the mechanical strength of the pressure chamber than in a configuration in which both the first circulating liquid chamber and the second circulating liquid chamber overlap the pressure chamber.
In a preferred example (aspect A14) according to the aspect A13, a height of the first circulating liquid chamber may be equal to a height of the second circulating liquid chamber. According to the aspect described above, an advantage is achieved in that a process of forming the first circulating liquid chamber and the second circulating liquid chamber is simplified.
In a preferred example (aspect A15) according to the aspect A13, a height of the first circulating liquid chamber may be larger than a height of the second circulating liquid chamber. According to the aspect described above, an advantage is achieved in that it is easy to maintain the mechanical strength of the pressure chamber.
In a preferred example (aspect A16) according to the aspect A13, a height of the first circulating liquid chamber may be smaller than a height of the second circulating liquid chamber. According to the aspect described above, an advantage is achieved in that it is easy to maintain the mechanical strength of the flow channel forming unit.
In a preferred example (aspect A17) according to the aspect A13, a width of the first circulating liquid chamber may be larger than a width of the second circulating liquid chamber.
In a preferred example (aspect A18) according to the aspect A13, a width of the first circulating liquid chamber may be smaller than a width of the second circulating liquid chamber.
In a preferred example (aspect A19) according to any one of the aspects A1 to A18, the flow channel forming unit may be provided with a liquid supply chamber that stores a liquid that is to be supplied to the pressure chamber, and the maximum value of the height of the circulating liquid chamber may be equal to a height of the liquid supply chamber. According to the aspect described above, since the height of the circulating liquid chamber is equal to the height of the liquid supply chamber, an advantage is achieved in that a process of forming the circulating liquid chamber and the liquid supply chamber is simplified.
In a preferred example (aspect A20) according to any one of the aspects A1 to A19, a partition wall having a predetermined thickness may be provided between the circulating liquid chamber and the communication channel. In the aspect described above, since the partition wall having the predetermined thickness is provided between the circulating liquid chamber and the communication channel, an advantage is achieved in that it is easy to maintain the mechanical strength of the circulating liquid chamber.
In a preferred example (aspect A21) according to any one of the aspects A1 to A20, the circulating liquid chamber may have a first space and a second space formed between flow channel walls, which are opposite to each other, on a side of the communication channel when viewed from the first space. The first location may be positioned within the first space, and the second location may be positioned within the second space. In the aspect described above, since the second space of the circulating liquid chamber is formed between the flow channel walls, an advantage is achieved in that it is easier to maintain the mechanical strength of the flow channel forming unit than in a configuration in which the flow channel walls are not formed.
In a preferred example (aspect A22) according to any one of the aspects A1 to A21, the liquid ejecting head may further include a wiring substrate having an end portion disposed on an opposite side of the nozzle plate with the flow channel forming unit interposed therebetween, and the circulating liquid chamber may overlap the end portion of the wiring substrate in a plan view. In the aspect described above, an external force is easy to be applied to the flow channel forming unit from the delivery substrate during installation of the wiring substrate. Hence, it is particularly preferable to employ the aspect described above in which it is possible to limit a reduction in mechanical strength of the flow channel forming unit.
According to another preferred aspect (aspect A23) of the present invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to any one of the aspects exemplified above. A preferable example of the liquid ejecting apparatus is a printing apparatus that ejects ink; however, a use of the liquid ejecting apparatus according to the present invention is not limited to printing.
Incidentally, in the technology in PTL 1, the front surface of the communication plate on which the nozzle plate is joined, is provided with the circulating communication channel. In such a configuration described above, it is actually difficult to efficiently circulate a liquid positioned in the vicinity of a nozzle to the circulation flow channel. With consideration for such circumstances described above, one of objects of a preferred aspect of the present invention is to efficiently circulate a liquid in the vicinity of a nozzle.
In order to solve such a problem described above, according to still another preferred aspect (aspect B1) of the present invention, there is provided a liquid ejecting head including: a nozzle plate provided with a first nozzle and a second nozzle; a flow channel forming unit provided with a first pressure chamber and a second pressure chamber to which a liquid is supplied, a first communication channel through which the first nozzle and the first pressure chamber communicate with each other, a second communication channel through which the second nozzle and the second pressure chamber communicate with each other, and a circulating liquid chamber that is positioned between the first communication channel and the second communication channel; and a pressure generating unit that generates a pressure change in each of the first pressure chamber and the second pressure chamber. The nozzle plate is provided with a first circulation channel, through which the first communication channel and the circulating liquid chamber communicate with each other, and a second circulation channel, through which the second communication channel and the circulating liquid chamber communicate with each other. According to the aspect described above, since the first circulation channel, through which the first communication channel and the circulating liquid chamber communicate with each other, is formed in the nozzle plate, it is possible to more efficiently supply a liquid in the vicinity of a nozzle to the circulating liquid chamber than in a configuration of PTL 1 in which the circulating communication channel is formed in the communication plate. In addition, since the first circulation channel and the second circulation channel commonly communicate with the circulating liquid chamber positioned between the first communication channel and the second communication channel, an advantage is achieved in that a configuration of the liquid ejecting head is more simplified than in a configuration in which a circulating liquid chamber communicating with the first circulation channel is separately provided from a circulating liquid chamber communicating with the second circulation channel. In the following description, an amount of a liquid flowing into the circulating liquid chamber via the first circulation channel of the liquid circulating in the first communication channel is referred to as a “circulation amount”, and an amount of a liquid that is ejected via the first nozzle of the liquid circulating in the first communication channel is referred to an “ejection amount”.
In a preferred example (aspect B2) according to the aspect B1, the first nozzle may be provided with a first zone and a second zone that has a diameter larger than that of the first zone and that is positioned on a side of the flow channel forming unit when viewed from the first zone. In the aspect described above, since the first nozzle is provided with the first zone and the second zone which have different inner diameters from each other, an advantage is achieved in that it is easy to set flow channel resistance of the first nozzle to a desired characteristic.
In a preferred example (aspect B3) according to the aspect B2, the first circulation channel may have the same depth as a depth of the second zone. In the aspect described above, since the first circulation channel has the same depth as the depth of the second zone of the first nozzle, an advantage is achieved in that it is easier to form the first circulation channel and the second zone than in a configuration in which the first circulation channel and the second zone have different depths from each other.
In a preferred example (aspect B4) according to the aspect B2, the first circulation channel may be deeper than the second zone. In the aspect described above, since the first circulation channel is deeper than the second zone of the first nozzle, the flow channel resistance of the first circulation channel is lower than that in a configuration in which the first circulation channel is shallower than the second zone. Hence, it is possible to more increase the circulation amount than in the configuration in which the first circulation channel is shallower than the second zone.
In a preferred example (aspect B5) according to the aspect B2, the first circulation channel may be shallower than the second zone. In the aspect described above, since the first circulation channel is shallower than the second zone of the first nozzle, the flow channel resistance of the first circulation channel is higher than that in a configuration in which the first circulation channel is deeper than the second zone. Hence, it is possible to more increase the ejection amount than in the configuration in which the first circulation channel is deeper than the second zone.
In a preferred example (aspect B6) according to any one of the aspects B2 to B5, the second zone may be continuous to the first circulation channel. In the aspect described above, the second zone of the first nozzle is continuous to the first circulation channel. Hence, the effect described above is remarkably achieved in that it is possible to efficiently circulate the liquid in the vicinity of the nozzle to the circulating liquid chamber.
In a preferred example (aspect B7) according to any one of the aspects B1 to B5, the first nozzle and the first circulation channel may be separated from each other in a plane of the nozzle plate. In the aspect described above, the first nozzle and the first circulation channel are separated from each other. Hence, an advantage is achieved in that ensuring of the circulation amount is easily compatible with ensuring of the ejection amount.
In a preferred example (aspect B8) according to the aspect B7, a flow channel length La of a portion of the first circulation channel, which overlaps the circulating liquid chamber, and a flow channel length Lb of a portion of the first circulation channel, which overlaps the first communication channel, may satisfy La>Lb. According to the aspect described above, an advantage is achieved in that it is easy to supply the liquid in the first communication channel to the circulating liquid chamber via the first circulation channel.
In a preferred example (aspect B9) according to the aspect B8, a flow channel length Lc of a portion of the first circulation channel, which overlaps a partition wall between the first communication channel and the circulating liquid chamber in the flow channel forming unit may satisfy La>Lb>Lc. According to the aspect described above, an advantage is achieved in that it is easy to supply the liquid in the first communication channel to the circulating liquid chamber via the first circulation channel.
In a preferred example (aspect B10) according to the aspect B6 or B7, a flow channel length La of a portion of the first circulation channel, which overlaps the circulating liquid chamber, and a flow channel length Lc of a portion of the first circulation channel, which overlaps a partition wall between the first communication channel and the circulating liquid chamber in the flow channel forming unit, may satisfy La>Lc. According to the aspect described above, an advantage is achieved in that it is easy to supply the liquid in the first communication channel to the circulating liquid chamber via the first circulation channel.
In a preferred example (aspect B11) according to any one of the aspects B1 to B10, a flow channel width of the first circulation channel may be smaller than a maximum diameter of the first nozzle. In the aspect described above, since the flow channel width of the first circulation channel is smaller than the maximum diameter of the first nozzle, the flow channel resistance of the first circulation channel is higher than that in a configuration in which the flow channel width of the first circulation channel is larger than the maximum diameter of the first nozzle. Hence, it is possible to increase the ejection amount.
In a preferred example (aspect B12) according to any one of the aspects B1 to B11, the flow channel width of the first circulation channel may be smaller than a flow channel width of the first pressure chamber. In the aspect described above, since the flow channel width of the first circulation channel is smaller than the flow channel width of the first pressure chamber, the flow channel resistance of the first circulation channel is higher than that in a configuration in which the flow channel width of the first circulation channel is larger than the flow channel width of the first pressure chamber. Hence, it is possible to increase the ejection amount.
In a preferred example (aspect B13) according to any one of the aspects B1 to B12, a flow channel width of a portion of the first circulation channel on a side of the circulating liquid chamber may be wider than a flow channel width of a portion thereof on a side of the first nozzle. In the aspect described above, since the flow channel width of the portion of the first circulation channel on the side of the circulating liquid chamber is wider than the flow channel width of the portion thereof on the side of the first nozzle, it is easy to supply the liquid in the first communication channel to the circulating liquid chamber via the first circulation channel. Hence, an advantage is achieved in that it is easy to ensure the circulation amount.
In a preferred example (aspect B14) according to any one of the aspects B1 to B12, a flow channel width of an intermediate portion of the first circulation channel may be narrower than the flow channel width of the portion thereof on the side of the circulating liquid chamber and the flow channel width of the portion thereof on the side of the first nozzle when viewed from the intermediate portion. In the aspect described above, since the flow channel width of the intermediate portion of the first circulation channel is narrower than that of the portion thereof on the side of the circulating liquid chamber and that of the portion thereof on the side of the first nozzle, the flow channel resistance of the first circulation channel is higher than that in a configuration in which the flow channel width of the first circulation channel is constant. Hence, it is possible to increase the ejection amount.
In a preferred example (aspect B15) according to any one of the aspects B1 to B12, a flow channel width of an intermediate portion of the first circulation channel may be wider than the flow channel width of the portion thereof on the side of the circulating liquid chamber and the flow channel width of the portion thereof on the side of the first nozzle when viewed from the intermediate portion. In the aspect described above, since the flow channel width of the intermediate portion of the first circulation channel is wider than that of the portion thereof on the side of the circulating liquid chamber and that of the portion thereof on the side of the first nozzle, the flow channel resistance of the first circulation channel is lower than that in a configuration in which the flow channel width of the first circulation channel is constant. Hence, it is possible to increase the circulation amount.
In a preferred example (aspect B16) according to any one of the aspects B1 to B15, a center axis of the first nozzle may be positioned on an opposite side of the circulating liquid chamber when viewed from a center axis of the first communication channel. In the aspect described above, since the center axis of the first nozzle is positioned on the opposite side of the circulating liquid chamber when viewed from the center axis of the first communication channel, it is possible to more decrease the circulation amount and more increase the ejection amount than in a configuration in which the center axis of the first nozzle is positioned on the side of the circulating liquid chamber when viewed from the center axis of the first communication channel.
In a preferred example (aspect B17) according to any one of the aspects B1 to B15, the center axis of the first nozzle may be positioned at the same location as the center axis of the first communication channel. In the aspect described above, as the center axis of the first nozzle and the center axis of the first communication channel are positioned at the same location, an advantage is achieved in that ensuring of the ejection amount is more easily compatible with ensuring of the circulation amount than in a configuration in which the center axis of the first nozzle and the center axis of the first communication channel are positioned at different locations from each other.
In a preferred example (aspect B18) according to any one of the aspects B1 to B15, the center axis of the first nozzle may be positioned on the side of the circulating liquid chamber when viewed from the center axis of the first communication channel. In the aspect described above, since the center axis of the first nozzle is positioned on the side of the circulating liquid chamber when viewed from the center axis of the first communication channel, it is possible to more increase the circulation amount and more decrease the ejection amount than in a configuration in which the center axis of the first nozzle is positioned on the opposite side of the circulating liquid chamber when viewed from the center axis of the first communication channel.
In a preferred example (aspect B19) according to any one of the aspects B1 to B18, the intermediate portion of the first circulation channel may be deeper than the portion thereof on the side of the circulating liquid chamber and the portion thereof on the side of the first nozzle when viewed from the intermediate portion. In the aspect described above, since the intermediate portion of the first circulation channel is deeper than the portion thereof on the side of the circulating liquid chamber and the portion thereof on the side of the first nozzle, the flow channel resistance of the first circulation channel is lower than that in a configuration in which the entire first circulation channel has a constant depth. Hence, it is possible to increase the circulation amount.
In a preferred example (aspect B20) according to any one of the aspects B1 to B19, when a pressure change is generated in the first pressure chamber, an amount of the liquid that is supplied to the circulating liquid chamber via the first circulation channel may be larger than an amount of the liquid that is ejected from the first nozzle. In the aspect described above, the circulation amount is larger than the ejection amount. In other words, it is possible to effectively circulate the liquid in the vicinity of the nozzle to the circulating liquid chamber while the ejection amount is ensured.
In a preferred example (aspect B21) according to any one of the aspects B1 to B20, the first circulation channel and the circulating liquid chamber may overlap each other, the first circulation channel and the first pressure chamber may overlap each other, and the circulating liquid chamber and the first pressure chamber may not overlap each other. In the aspect described above, the first circulation channel overlaps the circulating liquid chamber and the first pressure chamber, but the circulating liquid chamber and the first pressure chamber do not overlap each other. Hence, an advantage is achieved in that it is easier to decrease the liquid ejecting head in size than in a configuration in which the first circulation channel and the first pressure chamber do not overlap each other, for example.
In a preferred example (aspect B22) according to any one of the aspects B1 to B20, the first circulation channel and the circulating liquid chamber may overlap each other, the first circulation channel and the pressure generating unit may overlap each other, and the circulating liquid chamber and the pressure generating unit may not overlap each other. In the aspect described above, the first circulation channel overlaps the circulating liquid chamber and the pressure generating unit, but the circulating liquid chamber and the pressure generating unit do not overlap each other. Hence, an advantage is achieved in that it is easier to decrease the liquid ejecting head in size than in a configuration in which the first circulation channel and the pressure generating unit do not overlap each other, for example.
In a preferred example (aspect B23) according to any one of the aspects B1 to B20, an end surface of the first pressure chamber on a side of the first communication channel may be an inclined surface inclined with respect to an upper surface of the first pressure chamber, and the first circulation channel and the upper surface of the first pressure chamber may not overlap each other.
In a preferred example (aspect B24) according to any one of the aspects B1 to B23, the first pressure chamber and the circulating liquid chamber may communicate with each other via the first communication channel and the first circulation channel. In the aspect described above, the first pressure chamber and the circulating liquid chamber communicate with each other in a joint manner via the first communication channel and the first circulation channel. Hence, it is possible to supply the liquid to the circulating liquid chamber while the ejection amount is more appropriately ensured than in a configuration in which the first pressure chamber and the circulating liquid chamber directly communicate with each other.
In a preferred example (aspect B25) according to any one of the aspects B1 to B24, each of the nozzle plate and the flow channel forming unit may include a substrate formed by silicon. In the aspect described above, since each of the nozzle plate and the flow channel forming unit includes the silicon substrate, an advantage is achieved in that it is possible to form a flow channel in the nozzle plate and the flow channel forming unit with high accuracy by using a semiconductor manufacturing technology, for example.
According to still another preferred aspect of the present invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to any one of the aspects exemplified above. A preferable example of the liquid ejecting apparatus is a printing apparatus that ejects ink; however, a use of the liquid ejecting apparatus according to the present invention is not limited to printing.
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The moving mechanism 24 causes the liquid ejecting head 26 to reciprocate in an X direction under the control by the control unit 20. The X direction is a direction intersecting with (typically, orthogonal to) the Y direction in which the medium 12 is transported. The moving mechanism 24 of the first embodiment has a substantially box-shaped transport member 242 (carriage), which accommodates the liquid ejecting head 26, and a transport belt 244 to which the transport member 242 is fixed. It is possible to employ a configuration in which a plurality of liquid ejecting heads 26 are mounted on the transport member 242 or a configuration in which the liquid container 14 and the liquid ejecting head 26 are both mounted on the transport member 242.
The liquid ejecting head 26 eject ink, which is supplied from the liquid container 14, to the medium 12 from a plurality of nozzles N (ejecting holes) under the control by the control unit 20. The liquid ejecting head 26 ejects the inks to the medium 12 in parallel with transport of the medium 12 by the transport mechanism 22 and repeated reciprocating of the transport member 242, and thereby a desired image is formed on a front surface of the medium 12. Hereinafter, a direction perpendicular to an X-Y plane (for example, a plane parallel to the front surface of the medium 12) is referred to as a Z direction. A direction (typically, vertical direction) of ejecting ink by the liquid ejecting head 26 corresponds to the Z direction.
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The nozzle plate 52 is a plate-like member provided with the plurality of nozzles N and is disposed on the front surface Fb of the first flow channel substrate 32 by using an adhesive, for example. Each of the plurality of nozzles N is a circular through-hole through which the ink passes. The nozzle plate 52 of the first embodiment is provided with the plurality of nozzles N that configure the first array L1 and the plurality of nozzles N that configure the second array L2. Specifically, when viewed from the center plane O, the plurality of nozzles N of the first array L1 are formed along the Y direction in a region of the nozzle plate 52 on the positive side of the X direction, and the plurality of nozzles N of the second array L2 are formed along the Y direction in a region thereof on the negative side in the X direction. The nozzle plate 52 of the first embodiment is a single plate-like member in which a portion provided with the plurality of nozzles N of the first array L1 and a portion provided with the plurality of nozzles N of the second array L2 are continuous to each other. The nozzle plate 52 of the first embodiment is manufactured by processing a silicon (Si) monocrystalline substrate by using a semiconductor manufacturing technology (for example, a processing technology such as dry etching or wet etching). However, it is possible to optionally employ a known material or manufacturing method for manufacturing the nozzle plate 52.
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The protective member 46 of
An end portion of a wiring substrate 28 is joined to the front surface of the vibrating unit 42 (front surface of the flow channel forming unit 30) on the opposite side of the flow channel forming unit 30. In other words, the end portion of the wiring substrate 28 is joined to the front surface on the opposite side of the nozzle plate 52 with the flow channel forming unit 30 interposed therebetween. The wiring substrate 28 is a flexible mounting component provided with a plurality of wires (not shown) that electrically couples the control unit 20 to the liquid ejecting head 26. An end portion of the wiring substrate 28, which passes through an opening portion formed in the protective member 46 and an opening portion formed in the housing 48 and extends outside, is coupled to the control unit 20. For example, the flexible wiring substrate 28 such as a flexible printed circuit (FPC) or a flexible flat cable (FFC) is preferably employed.
The housing 48 is a case for storing ink that is supplied to the plurality of pressure chambers C (further to the plurality of nozzles N). For example, a front surface of the housing 48 on the positive side in the Z direction is joined to the front surface Fa of the first flow channel substrate 32 with an adhesive. It is possible to optionally employ a known material or manufacturing method for manufacturing the housing 48. For example, it is possible to form the housing 48 by injection molding of a resin material.
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As described above, the plurality of pressure chambers C and the plurality of piezoelectric elements 44 are arranged in the Y direction in each of the first portion P1 and the second portion P2. This can also be described as follows. The circulating liquid chamber 65 extends in the Y direction to be continuous over the plurality of pressure chambers C or the plurality of piezoelectric elements 44 in each of the first portion P1 and the second portion P2. In addition, as understood from
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Each of the circulation channels 72 is a groove (that is, a bottomed hole having an elongated shape) extending in the X direction and functions as a flow channel through which the ink is circulated. The circulation channel 72 of the first embodiment is formed at a position separated from the nozzle N (specifically, on a side of the circulating liquid chamber 65 when viewed from the nozzle N corresponding to the circulation channel 72). For example, the plurality of nozzles N (particularly, the second zone n2) and the plurality of circulation channels 72 are collectively formed in a common process by the semiconductor manufacturing technology (for example, a processing technology such as dry etching or wet etching).
As illustrated in
Any one circulation channel 72 in the first portion P1 is positioned on the side of the circulating liquid chamber 65 when viewed from the nozzle N of the first array L1, the nozzle corresponding to the circulation channel 72. In addition, any one circulation channel 72 in the second portion P2 is positioned on the side of the circulating liquid chamber 65 when viewed from the nozzle N of the second array L2, the nozzle corresponding to the circulation channel 72. An end portion of the circulation channel 72 on the opposite side (side of the communication channel 63) of the center plane O overlaps one communication channel 63 corresponding to the circulation channel 72 in a plan view. In other words, the circulation channel 72 communicates with the communication channel 63. On the other hand, an end portion of the circulation channel 72 on the side (side of the circulating liquid chamber 65) of the center plane O overlaps the circulating liquid chamber 65 in a plan view. In other words, the circulation channel 72 communicates with the circulating liquid chamber 65. As understood from the description provided above, each of the plurality of communication channels 63 communicates with the circulating liquid chamber 65 via the circulation channel 72. Hence, as illustrated by a dashed-line arrow in
As described above, in the first embodiment, the pressure chamber C indirectly communicates with the circulating liquid chamber 65 via the communication channel 63 and the circulation channel 72. In other words, the pressure chamber C and the circulating liquid chamber 65 do not directly communicate with each other. In the configuration described above, when the pressure in the pressure chamber C changes due to an operation of the piezoelectric element 44, a part of ink flowing in the communication channel 63 is ejected outside from the nozzle N, and a part of the rest ink flows into the circulating liquid chamber 65 from the communication channel 63 through the circulation channel 72. In the first embodiment, inertance of the communication channel 63, the nozzle, and the circulation channel 72 is selected such that an amount of ink that is ejected via the nozzle N (hereinafter, referred to as an “ejection amount”) of the ink circulating in the communication channel 63 by driving the piezoelectric element 44 once is larger than an amount of ink that flows into the circulating liquid chamber 65 via the circulation channel 72 (hereinafter, referred to as a “circulation amount”) of the ink circulating in the communication channel 63. This can also be described as follows. When a case of driving all of the piezoelectric elements 44 at once is assumed, a total of circulation amounts of flowing into the circulating liquid chamber 65 from the plurality of communication channels 63 (for example, a flow amount in the circulating liquid chamber 65 within a unit time) is larger than a total of ejection amounts by the plurality of nozzles N.
Specifically, the flow channel resistance of each of the communication channel 63, the nozzle, and the circulation channel 72 is determined such that a ratio of the circulation amount to the ink circulating in the communication channel 63 is equal to or higher than 70% (a ratio of the ejection amount is equal to or lower than 30%). According to the configuration described above, it is possible to effectively circulate ink in the vicinity of the nozzle to the circulating liquid chamber 65 while the ejection amount of the ink is ensured. Schematically, the higher the flow channel resistance of the circulation channel 72 is, the more the circulation amount decreases, whereas the more the ejection amount increases. The lower the flow channel resistance of the circulation channel 72 is, the more the circulation amount tends to increase, whereas the more the ejection amount decreases.
As illustrated in
As understood from
As described above, the circulation channel 72 and the communication channel 63 overlap each other in a plan view, and the communication channel 63 and the pressure chamber C overlap each other in a plan view. Hence, the circulation channel 72 and the pressure chamber C overlap each other in a plan view. On the other hand, as understood from
As described above, in the first embodiment, the circulation channel 72 through which the communication channel 63 and the circulating liquid chamber 65 communicate with each other is formed in the nozzle plate 52. Hence, compared with a configuration in PTL 1 in which a circulating communication channel is formed in a communication plate, it is possible to more efficiently circulate the ink in the vicinity of the nozzle N to the circulating liquid chamber 65. In addition, in the first embodiment, the communication channels 63 corresponding to the first array L1 and the communication channels 63 corresponding to the second array L2 commonly communicate with the circulating liquid chamber 65 between both the communication channels. Hence, an advantage is achieved in that a configuration of the liquid ejecting head 26 is more simplified (therefore, miniaturization is realized) than in a configuration in which a circulating liquid chamber communicating with the circulation channels 72 corresponding to the first array L1 is separately provided from a circulating liquid chamber communicating with the circulation channels 72 corresponding to the second array L2.
A second embodiment of the present invention is described. Elements having the same operations or functions in aspects, which will be exemplified below, as those in the first embodiment are assigned with the same reference signs used in the description of the first embodiment, and thus the detailed descriptions thereof are appropriately omitted.
In the first embodiment, a configuration in which the circulation channel 72 and the nozzle N are separated from each other is exemplified. In the second embodiment, as understood from
Also in the second embodiment, the same effects as those of the first embodiment are realized. In addition, in the second embodiment, the second zones n2 of the nozzles N and the circulation channels 72 are continuous to each other. Hence, compared with the configuration of the first embodiment in which the circulation channel 72 and the nozzle N are separated from each other, an effect is particularly remarkable in that it is possible to efficiently circulate the ink in the vicinity of the nozzle N to the circulating liquid chamber 65.
The circulation channel 72 of the third embodiment is a groove that extends in the X direction over the circulating liquid chamber 65 and the circulating liquid chamber 67 in each of the first portion P1 and the second portion P2. Specifically, an end portion of the circulation channel 72 on the side (side of the circulating liquid chamber 65) of the center plane O overlaps the circulating liquid chamber 65 in a plan view, and an end portion of the circulation channel 72 on the opposite side (side of the circulating liquid chamber 67) of the center plane O overlaps the circulating liquid chamber 67 in a plan view. In addition, the circulation channel 72 overlaps the communication channel 63 in a plan view. In other words, the communication channels 63 communicate with both the circulating liquid chamber 65 and the circulating liquid chamber 67 via the circulation channels 72.
In other words, the nozzle N (first zone n1) is formed on the bottom surface of the circulation channel 72. Specifically, the first zone n1 of the nozzle N is formed on the bottom surface of a portion of the circulation channel 72, which overlaps the communication channel 63 in a plan view. Similarly to the second embodiment, also in the third embodiment, it is possible to realize a configuration in which the circulation channel 72 and the nozzle N (second zone n2) are continuous to each other. As understood from the description provided above, the communication channel 63 and the nozzle N are positioned on the end portion of the circulation channel 72 in the first and second embodiments, and the communication channel 63 and the nozzle N are positioned in an intermediate portion of the circulation channel 72 extending in the X direction in the third embodiment.
As understood from the description provided above, in the third embodiment, when the pressure in the pressure chamber C changes in the pressure chamber C, a part of ink flowing in the communication channel 63 is ejected outside from the nozzle N, and a part of the rest ink is supplied to both the circulating liquid chamber 65 and the circulating liquid chamber 67 from the communication channel 63 through the circulation channel 72. The ink in the circulating liquid chamber 67 and the ink in the circulating liquid chamber 65 are together suctioned by the circulation mechanism 75. Then, after bubbles or foreign matter is removed by the circulation mechanism 75, and thickening is lowered, the ink is supplied to the liquid reservoir R.
Also in the third embodiment, the same effects as those of the first embodiment are realized. In addition, in the third embodiment, in addition to the circulating liquid chamber 65, the circulating liquid chamber 67 is formed, and thus an advantage is achieved in that it is possible to ensure sufficient circulation amount more than in the first embodiment.
As illustrated in
As understood from
In addition, as understood from
As illustrated in
The plurality of second spaces 652 are formed to correspond to the plurality of communication channels 63, respectively, and communicate with the first space 651. A second space 652 corresponding to any one communication channel 63 overlaps the circulation channel 72 corresponding to the communication channel 63 in a plan view. Hence, ink in the communication channels 63 is supplied to the first space 651 via the circulation channel 72 and the second space 652 and is circulated to the liquid reservoir R by the circulation mechanism 75.
The upper surface of the second space 652 is an inclined surface having a height H that decreases from the negative side (side of the first space 651) toward the positive side (side of the communication channel 63) in the X direction. In addition, a flow channel wall 692 is formed between the two spaces 652 adjacent to each other in the Y direction. The flow channel walls 692 are partition wall-shaped portions of the second spaces 652. A wall (part of the partition wall 69) having a constant thickness is formed between the second spaces 652 and the communication channels 63.
As understood from
As illustrated in
As illustrated in
Each of the plurality of grooves 665 in the region G1 is formed into a curved shape that is convex on the positive side in the Y direction (exemplifying a first side in a first direction) in a plan view. For example, the plurality of grooves 665 having an arc shape that is convex on the positive side in the Y direction are formed in the region G1. On the other hand, each of the plurality of grooves 665 in the region G2 is formed into a curved shape that is convex on the negative side in the Y direction (exemplifying a second side in the first direction) in a plan view. For example, the plurality of grooves 665 having the arc shape that is convex on the negative side in the Y direction are formed in the region G2.
Ink that flows into the circulating liquid chamber 65 and reaches the vicinity of the upper surface of the circulating liquid chamber 65 is likely to move along the grooves 665. In other words, according to the sixth embodiment, it is possible to adjust a range in which the ink in the circulating liquid chamber 65 flows.
For example, the grooves 665 in the region G1 are convex on the positive side in the Y direction. Hence, the ink that flows into the circulating liquid chamber 65 from the communication channel 63 (that is, on the positive side in the X direction) in the first portion P1 is likely to flow toward the negative side (side of the circulation port 65b) in the Y direction along the grooves 665 in the region G1, as shown by an arrow a1 in
As illustrated in
In addition, as illustrated in
As understood from
As illustrated in
As illustrated in
As illustrated in
As illustrated in
Any configuration of the first to third embodiments can be employed as configurations that are not particularly mentioned in the description provided above regarding the fourth to seventh embodiments. For example, the configurations of the first to third embodiments related to the circulation channel 72 or the nozzle N can be applied to any example selected from the fourth to seventh embodiments. In the first to third embodiments, the circulation channel 72 is formed in the nozzle plate 52; however, in the fourth to seventh embodiments, the circulation channel, through which the communication channel 63 and the circulating liquid chamber 65 communicate with each other, can be formed in the first flow channel substrate 32 (for example, the front surface Fb).
In the fourth to seventh embodiments, the height of the circulating liquid chamber 65 is different depending on a position in the X direction. According to the configuration described above, it is possible to more limit a reduction in mechanical strength of the flow channel forming unit 30 than in the configurations of the first to third embodiments in which the upper surface of the circulating liquid chamber 65 is parallel to the X-Y plane. In the fourth to seventh embodiments, the circulating liquid chamber 65 overlaps the end portion of the wiring substrate 28 in a plan view. In the configuration described above, the first flow channel substrate 32 is pressed in the Z direction during the mounting of the wiring substrate 28. The configurations of the fourth to seventh embodiments in which it is possible to ensure the mechanical strength of the flow channel forming unit 30 are particularly effective from the viewpoint of preventing the first flow channel substrate 32 from being broken or the like due to the press during the mounting of the wiring substrate 28. In a configuration in which the circulating liquid chamber 65 has a corner, bubbles mixed in ink are likely to remain in the corner. According to the configuration in which the upper surface of the circulating liquid chamber 65 has the curved shape as in the fourth embodiment, remaining of the bubbles is limited, and thus it is possible to effectively discharge the bubbles mixed in the ink.
The embodiments described above can be modified in various ways. Specific modification examples that can be applied to the embodiments described above are described as follows. Two or more examples optionally selected from below can be appropriately combined within a range in which the examples are compatible with each other.
(1) In the embodiments described above, the configuration in which the circulation channel 72 and the second zone n2 of the nozzle N have the same depth is exemplified; however, a relationship between the depth of the circulation channel 72 and the depth of the second zone n2 is not limited to that described above. For example, it is possible to employ a configuration in which the circulation channel 72 deeper than the second zone n2 is formed as illustrated in
(2) In the embodiments described above, the configuration in which the depth Da of the circulation channel 72 is constant is exemplified; however, it is possible to change the depth of the circulation channel 72 depending on a position in the X direction. For example, as illustrated in
(3) In the embodiments described above, the configuration in which the flow channel width Wa of the circulation channel 72 is equal to the maximum diameter of the nozzle N (the inner diameter d2 of the second zone n2) is exemplified; however, the flow channel width Wa is not limited to that described above. For example, it is also possible to employ a configuration in which the flow channel width Wa of the circulation channel 72 is smaller than the maximum diameter of the nozzle N (the inner diameter d2 of the second zone n2). According to the configuration described above, the flow channel resistance of the circulation channel 72 is higher than that in the configuration in which the circulation channel 72 is larger than the maximum diameter of the nozzle N. Hence, it is possible to increase the ejection amount. In addition, it is also possible to employ a configuration in which the flow channel width Wa of the circulation channel 72 is larger than the inner diameter d1 of the first zone n1). According to the configuration described above, ensuring of the circulation amount is compatible with ensuring of the ejection amount.
(4) In the embodiments described above, the configuration in which the flow channel width Wa of the circulation channel 72 is constant is formed; however, it is possible to change the flow channel width of the circulation channel 72 depending on a position in the X direction. For example, as illustrated in
In addition, as illustrated in
As illustrated in
It is necessary to form the thick partition wall 69 in order to ensure the mechanical strength of the partition wall 69 of the first flow channel substrate 32. However, the thicker the partition wall 69 (the longer the flow channel length Lc) is, the more the flow channel resistance of the circulation channel 72 increases. According to a configuration in
(5) In the embodiments described above, the configuration in which the center axis Qa of the nozzle N is positioned on the opposite side of the circulating liquid chamber 65 when viewed from the center axis Qb of the communication channel 63 is exemplified; however, a relationship between the center axis Qa of the nozzle N and the center axis Qb of the communication channel 63 is not limited to that described above. For example, as illustrated in
In addition, as illustrated in
(6) In the fourth to seventh embodiments, the configuration in which the upper surface of the circulating liquid chamber 65 or the circulating liquid chamber 67 is curved is exemplified; however, a shape for making the height of the circulating liquid chamber 65 or the circulating liquid chamber 67 different depending on a position is not limited to that described above. For example, as illustrated in
(7) As illustrated in
(8) In the embodiments described above, the configuration in which the elements related to the first array L1 are disposed in plane symmetry with the elements related to the second array L2 with the center plane O interposed therebetween is exemplified; however, there is no need to employ the plane-symmetrical configuration. For example, it is also possible to employ a configuration in which the elements corresponding only to the first array L1 are arranged in the same manner as in the embodiments described above. In addition, in the embodiments described above, the configuration in which the circulation channel 72 is formed in the nozzle plate 52 is exemplified; however, the flow channels, through which the communication channels 63 and the circulating liquid chamber 65 communicate with each other, can be formed in the flow channel forming unit 30 (for example, the front surface Fb of the first flow channel substrate 32).
(9) An element (pressure generating unit) that applies the pressure to the inside of the pressure chamber C is not limited to the piezoelectric element 44 exemplified in the embodiments described above. For example, it is also possible to use, as the pressure generating unit, a heating element that generates bubbles inside the pressure chamber C through heating and changes the pressure. The heating element is a portion (specifically, a region that generates bubbles in the pressure chamber C) in which a heating body is heated by supply of a drive signal. As understood from the description provided above, the pressure generating unit is collectively referred to as an element that ejects, from the nozzle N, a liquid in the pressure chamber C (typically, an element that applies pressure to the inside of the pressure chamber C), regardless of an operation method (piezoelectric method/heading method) or a specific configuration.
(10) In the embodiments described above, a serial type liquid ejecting apparatus 100 in which the transport member 242, on which the liquid ejecting head 26 is mounted, reciprocates is exemplified; however, the present invention can be applied to a line type liquid ejecting apparatus in which the plurality of nozzles N are arranged over the entire width of the medium 12.
(11) The liquid ejecting apparatus 100 exemplified in the embodiments described above can be employed in various types of machines such as a facsimile machine or a copy machine, in addition to a machine dedicated to printing. However, the use of the liquid ejecting apparatus of the present invention is not limited to the printing. For example, a liquid ejecting apparatus that ejects a solution of a color material is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. In addition, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms a wiring or an electrode of the wiring substrate.
100 LIQUID EJECTING APPARATUS
12 MEDIUM
14 LIQUID CONTAINER
20 CONTROL UNIT
22 TRANSPORT MECHANISM
24 MOVING MECHANISM
242 TRANSPORT MEMBER
244 TRANSPORT BELT
26 LIQUID EJECTING HEAD
28 WIRING SUBSTRATE
30 FLOW CHANNEL FORMING UNIT
32 FIRST FLOW CHANNEL SUBSTRATE
34 SECOND FLOW CHANNEL SUBSTRATE
42 VIBRATING UNIT
44 PIEZOELECTRIC ELEMENT
46 PROTECTIVE MEMBER
48 HOUSING
482 INTRODUCTION PORT
52 NOZZLE PLATE
54 VIBRATION ABSORBER
61 SUPPLY CHANNEL
63 COMMUNICATION CHANNEL
65 CIRCULATING LIQUID CHAMBER
65
a, 65b CIRCULATION PORT
651 FIRST SPACE
652 SECOND SPACE
665 GROOVE
67 CIRCULATING LIQUID CHAMBER
69 PARTITION WALL
692 FLOW CHANNEL WALL
n1 FIRST ZONE
n2 SECOND ZONE
72 CIRCULATION CHANNEL
75 CIRCULATION MECHANISM
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-249118 | Dec 2016 | JP | national |
| 2017-026372 | Feb 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/043977 | 12/7/2017 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2018/116846 | 6/28/2018 | WO | A |
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| 20080198208 | Kyoso et al. | Aug 2008 | A1 |
| 20110148988 | Hoisington et al. | Jun 2011 | A1 |
| 20110234705 | Fukada | Sep 2011 | A1 |
| 20120176450 | Akahane et al. | Jul 2012 | A1 |
| 20140036001 | Hoisington | Feb 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| 2008-200902 | Sep 2008 | JP |
| 2011-520671 | Jul 2011 | JP |
| 2011-218784 | Nov 2011 | JP |
| 2012-143948 | Aug 2012 | JP |
| 2012143948 | Aug 2012 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20190366717 A1 | Dec 2019 | US |
