Patent ID: 12251942

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the present disclosure are described below with reference to the drawings. In the drawings, the dimension and scale of each portion may be appropriately different from actual dimension and scale. The embodiments described below are favorable specific examples of the present disclosure, and thus there are various limitations that are technically favorable; however, the scope of the present disclosure is not limited to those modes unless there is otherwise stated in the following descriptions that the present disclosure is particularly limited.

In the following descriptions, three directions crossing each other may be described as an X-axis direction, a Y-axis direction, and a Z-axis direction. The X-axis direction includes an X1direction and an X2direction that are directions opposite to each other. The Y-axis direction includes a Y1direction and a Y2direction that are directions opposite to each other. The Z-axis direction includes a Z1direction and a Z2direction that are directions opposite to each other. The X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other. The Z1direction is along an ejecting direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are based on a posture of a liquid ejecting head10. As described later, the X-axis direction, the Y-axis direction, and the Z-axis direction can be changed with respect to a gravity direction G1in accordance with a posture change in the liquid ejecting head10.

In the drawings, the X-axis direction, the Y-axis direction, and the Z-axis direction are indicated by arrows; however, when the posture of the liquid ejecting head10is changed, arrangement of parts other than the liquid ejecting head10may not correspond to the X-axis direction, the Y-axis direction, and the Z-axis direction. In the schematic diagrams such asFIGS.1and2, the arrangement may not correspond to actual arrangement. For example, multiple head chips20are illustrated away from each other in the Y-axis direction inFIG.2; however, the multiple head chips20are partially overlapped with each other when viewed in the X-axis direction as illustrated inFIG.4. Since other drawings are also illustrated schematically, the shape may be different from the reality. The positional relationship between parts may not correspond completely to the actual positional relationship as well.

FIG.1is a schematic diagram illustrating a liquid ejecting apparatus1according to Embodiment 1.FIG.2is a schematic diagram illustrating an ink flow channel in the liquid ejecting apparatus1. The liquid ejecting apparatus1is an ink jet type printing apparatus that ejects ink, which is an example of a “liquid”, onto a medium PA as an ink droplet. The liquid ejecting apparatus1is a serial type printing apparatus, for example. The liquid ejecting head10ejects the ink onto the medium PA while moving in a width direction of the medium PA. The medium PA is typically a print sheet. The medium PA is not limited to a print sheet and, for example, may be a printing target of an arbitrary material such as a resin film or a fabric.

The liquid ejecting apparatus1includes multiple liquid containers2, a medium transporting mechanism4, a carriage5, a carriage transporting mechanism6, a control unit30, and the multiple liquid ejecting heads10. The liquid ejecting apparatus1includes a circulating mechanism110. The liquid ejecting apparatus1may include the single liquid ejecting head10or may include the multiple liquid ejecting heads10. The liquid ejecting apparatus1can execute a recording operation to eject and apply the ink onto the medium PA. The liquid ejecting apparatus1can execute a maintenance operation. The maintenance operation includes an operation that is necessary to perform the ink ejection in a normal manner during the recording operation. The maintenance operation includes an operation to discharge air bubbles in the ink. The maintenance operation may include an operation to appropriately maintain the viscosity of the ink and an operation to appropriately maintain the ejecting direction of the ink.

The control unit30controls operations of elements in the liquid ejecting apparatus1. The control unit30includes a processing circuit such as a CPU or an FPGA and a memory circuit such as a semiconductor memory, for example. The memory circuit stores various programs and various data. The processing circuit implements various kinds of control by executing the programs and appropriately using the data. The CPU is an abbreviation of a central processing unit. The FPGA is an abbreviation of a field programmable gate array.

The medium transporting mechanism4is controlled by the control unit30to transport the medium PA in a transporting direction DM. The positional relationship between the transporting direction DM of the medium PA and an ejecting surface F1of the liquid ejecting head10when printing is performed by ejecting the ink from the liquid ejecting head10in a printing apparatus is widely known. When printing is performed by ejecting the ink from the liquid ejecting head10, the ejecting surface F1of the liquid ejecting head10may be parallel to or substantially parallel to the transporting direction DM and the Y-axis direction. The posture of the liquid ejecting head10is changed, and the Y-axis direction is also changed along with the posture of the liquid ejecting head10. The medium transporting mechanism4includes a transporting roller that is long along the width direction of the medium PA and a motor rotating the transporting roller. The medium transporting mechanism4is not limited to the configuration using the transporting roller and may have a configuration using a drum or an endless belt that transports the medium PA while the medium PA clings onto an outer periphery surface with electrostatic force or the like, for example. The multiple liquid ejecting heads10are mounted in the carriage5.

The liquid container2reserves the ink. A specific aspect of the liquid container2may include, for example, a cartridge that is attachable and detachable to and from the liquid ejecting apparatus1, an ink pack in the form of a bag formed of a flexible film, and an ink tank that can be refilled with the ink. The type of the ink reserved in the liquid container2is arbitrary.

As illustrated inFIG.2, the liquid ejecting apparatus1includes the circulating mechanism110. The circulating mechanism110includes a sub tank111, a pump112, a temperature adjusting unit113, an ink supply flow channel114, and an ink discharge flow channel115. The circulating mechanism110collects the ink that is not ejected from a nozzle N of the liquid ejecting head10and supplies the ink to the liquid ejecting head10again. The sub tank111is a tank that temporarily reserves the ink. The sub tank111is coupled with the liquid container2. The sub tank111is supplied with the ink from the liquid container2. In a flow channel through which the ink flows, the terms “upstream” and “downstream” may be used based on the liquid ejecting head10. Specifically, from the liquid ejecting head10to the sub tank111, a portion in which the ink flows from the sub tank111toward the liquid ejecting head10in a circulating operation, which is described later, is upstream of the liquid ejecting head10, and a portion in which the ink flows from the liquid ejecting head10toward the sub tank111is downstream of the liquid ejecting head10.

The sub tank111is provided with a pressure adjusting unit111b. The pressure adjusting unit111bis a compressor, for example, and can adjust the pressure in the sub tank111. The pressure adjusting unit111bcan make the pressure in the sub tank111negative.

The ink supply flow channel114is a flow channel to supply the ink in the sub tank111to the liquid ejecting head10. The ink supply flow channel114includes, for example, a flow channel member, a pipe, a tube, and the like in which a groove, a recess portion, a through-hole, and the like are formed. The ink supply flow channel114includes a flow channel provided upstream of the liquid ejecting head10.

The pump112is a pump provided in the ink supply flow channel114to supply the ink in the sub tank111to the liquid ejecting head10. The pump112may be a tube pump, for example. The pump112may be another pump such as a syringe pump or a diaphragm pump, for example.

The temperature adjusting unit113is coupled to the ink supply flow channel114and adjusts the temperature of the ink. The temperature adjusting unit113is arranged downstream of the pump112, for example. For example, the temperature adjusting unit113includes a tank that temporarily reserves the ink and a heater that heats up the temperature of the ink in the tank. The ink at the temperature adjusted by the temperature adjusting unit113is supplied to the liquid ejecting head10. For example, the heater of the temperature adjusting unit113may have a configuration of being controlled by the control unit30based on information detected by a temperature sensor135described later.

The flow channel of the ink in the liquid ejecting head10is described later. The ink discharge flow channel115is a flow channel to discharge the ink in the liquid ejecting head10to the sub tank111. The ink discharge flow channel115includes, for example, a flow channel member, a pipe, a tube, and the like in which a groove, a recess portion, a through-hole, and the like are formed. The ink discharge flow channel115includes a flow channel provided downstream of the liquid ejecting head10.

A flow of the ink in the liquid ejecting head10is described. The liquid ejecting head10includes the multiple head chips20. Each head chip20is provided with the multiple nozzles N. The nozzles N are illustrated inFIGS.3and4. The multiple head chips20include head chips20A,20B,20C, and20D. The arrangement of the multiple head chips20A,20B,20C, and20D is described later. When the multiple head chips20A,20B,20C, and20D are not distinguished from each other, they may be described as the head chip20.

The head chip20A is provided with a common liquid chamber RA. The head chip20B is provided with a common liquid chamber RB. The head chip20C is provided with a common liquid chamber RC. The head chip20D is provided with a common liquid chamber RD. When the common liquid chambers RA to RD are not distinguished from each other, they may be described as a common liquid chamber R.

As illustrated inFIG.3, the multiple nozzles N communicate with the common liquid chamber R. The common liquid chamber R extends in a longitudinal direction of the head chip20. The head chip20is provided with an ink supply port46to supply the common liquid chamber R with the ink and an ink discharge port47to discharge the ink from the common liquid chamber R. As illustrated inFIG.2, the head chip20A is provided with an ink supply port46A and an ink discharge port47A. The head chip20B is provided with an ink supply port46B and an ink discharge port47B. The head chip20C is provided with an ink supply port46C and an ink discharge port47C. The head chip20D is provided with an ink supply port46D and an ink discharge port47D. When the ink supply ports46A to46D are not distinguished from each other, they may be described as the ink supply port46. When the ink discharge ports47A to47D are not distinguished from each other, they may be described as the ink discharge port47.

The liquid ejecting head10includes a flow channel116, flow channels117A to117D, flow channels118A to118D, and a flow channel119. The liquid ejecting head10includes the temperature sensor135that detects information on the temperature of the ink flowing through the flow channel in the liquid ejecting head10, filters136A to136D, and a check valve137.

The flow channel116and the flow channels117A to117D are coupled to the ink supply flow channel114. The flow channel116and the flow channels117A to117D are flow channels to supply the multiple head chips20A to20D with the ink. The flow channels117A to117D are flow channels diverging from the flow channel116.

The flow channel117A is coupled to the ink supply port46A of the head chip20A. The flow channel117B is coupled to the ink supply port46B of the head chip20B. The flow channel117C is coupled to the ink supply port46C of the head chip20C. The flow channel117D is coupled to the ink supply port46D of the head chip20D.

The flow channel116and the flow channels117A to117D include, for example, a flow channel member, a pipe, a tube, and the like in which a groove, a recess portion, a through-hole, and the like are formed. The ink supplied to the liquid ejecting head10flows inside the flow channel116and then flows into each of the flow channels117A to117D.

The ink in the flow channel117A is supplied to the common liquid chamber RA of the head chip20A. The ink in the flow channel117B is supplied to the common liquid chamber RB of the head chip20B. The ink in the flow channel117C is supplied to the common liquid chamber RC of the head chip20C. The ink in the flow channel117D is supplied to the common liquid chamber RD of the head chip20D.

FIG.3is a schematic diagram illustrating the common liquid chamber R, pressure chambers C, and the nozzles N. InFIG.3, the arrangement of the common liquid chamber R, the pressure chambers C, and the nozzles N when viewed in the Z1direction is illustrated. InFIG.3, illustration of some of the multiple pressure chambers C and nozzles N is omitted. The head chip20includes the common liquid chamber R, the pressure chambers C, and the nozzles N. The head chip20includes the multiple pressure chambers C arrayed in the Y-axis direction. The multiple nozzles N communicate with the respective multiple pressure chambers C. The common liquid chamber R communicates with the multiple pressure chambers C. The common liquid chamber R extends in the Y-axis direction.

The ink supply port46and the ink discharge port47communicate with the common liquid chamber R. The ink supplied to the head chip20passes through the ink supply port46and flows into the common liquid chamber R. The ink in the common liquid chamber R is supplied to the multiple pressure chambers C. The ink in the pressure chambers C is ejected from the nozzles N. The ink that is not discharged from the nozzles N flows inside the common liquid chamber R and is discharged from the ink discharge port47. The ink in the common liquid chamber R flows from the ink supply port46toward the ink discharge port47in the Y-axis direction.

The ink discharged from the common liquid chamber RA of the head chip20A flows inside the flow channel118A and flows into the flow channel119. The ink discharged from the common liquid chamber RB of the head chip20B flows inside the flow channel118B and flows into the flow channel119. The ink discharged from the common liquid chamber RC of the head chip20C flows inside the flow channel118C and flows into the flow channel119. The ink discharged from the common liquid chamber RD of the head chip20D flows inside the flow channel118D and flows into the flow channel119. The flows of the ink in the flow channels118A to118D are converged.

The check valve137is coupled to the flow channel119. The check valve137prevents a backflow of the ink from the flow channel119toward the flow channels118A to118D. The ink in the flow channel119is discharged to the outside of the liquid ejecting head10. The ink in the flow channel119flows inside the ink discharge flow channel115and flows into the sub tank111. The ink discharged from the liquid ejecting head10is collected into the sub tank111. The ink in the sub tank111flows inside the ink supply flow channel114and is supplied to the liquid ejecting head10. The ink is thus circulated.

The liquid ejecting head10is described.FIG.5is a perspective view illustrating the multiple liquid ejecting heads10.FIG.6is an exploded perspective view illustrating the liquid ejecting head10. The multiple liquid ejecting heads10are mounted in the carriage5as described above. As illustrated inFIG.6, the liquid ejecting head10includes a fixing plate11, the multiple head chips20provided with the nozzles N, a holder13holding the fixing plate11and the head chips20, a flow channel structure14forming the flow channels of the ink, a relay substrate15arranged on the top of the flow channel structure14, a connector16provided on the relay substrate15, and a top cover17.

The fixing plate11forms a bottom surface of the liquid ejecting head10. In the fixing plate11, an opening11ato expose the nozzles N of the head chips20is formed.

The multiple head chips20are arranged at the bottom of the liquid ejecting head10and are held by the holder13. The head chips20are each provided with the multiple nozzles N ejecting the liquid. The multiple nozzles N are arrayed in the Y-axis direction to form a nozzle row NL. The size, the number, the positional relationship, and the like of the illustrated nozzles N are not the same as that in reality. As mentioned before, the drawings are schematically illustrated and may be different from the reality.

The flow channel structure14is arranged on the holder13. In the flow channel structure14, the flow channels through which the ink flows are formed. The flow channel structure14includes multiple flow channel substrates19. The multiple flow channel substrates19are layered in a plate thickness direction thereof. In each flow channel substrate19, a groove and an opening are formed, for example. The flow channels are formed of those groove and opening. The flow channel116, the flow channels117A to117D, the flow channels118A to118D, and the flow channel119illustrated inFIG.2are formed in the flow channel structure14.

The flow channel structure14is provided with an ink supply port14ato introduce the ink to the inside of the flow channel structure14and an ink discharge port14bto discharge the ink from the flow channel structure14. The ink supply port14aand the ink discharge port14bof the present embodiment are provided so as to project in the Z2direction from the flow channel substrate19arranged at the uppermost in the Z-axis direction, that is, in the Z2direction.

The relay substrate15covers the top of the center portion in the Y-axis direction of the flow channel structure14. The relay substrate15is provided with multiple electric wirings. The relay substrate15is electrically coupled with a COF60of the head chip20that is described later in detail through a not-illustrated wiring member.

The connector16protrudes upward from the relay substrate15. The connector16is electrically coupled with an electric part outside the liquid ejecting head10. The head chip20is electrically coupled with the control unit30through the connector16.

An end portion of the top cover17in the Z1direction is in contact with a surface of the holder13in the Z2direction, and the top cover17stores the flow channel structure14, the relay substrate15, and the connector16between the end portion of the top cover17and the surface of the holder13in the Z2direction. An upper surface of the top cover17on a side of the Z2direction is provided with a wiring opening17ato insert an external wiring member into the connector16and openings17band17cto couple the ink supply port14aand the ink discharge port14bwith a flow channel member outside the liquid ejecting head10such as a tube. The ink supply flow channel114and the ink discharge flow channel115are formed inside this flow channel member outside the liquid ejecting head10.

InFIG.4, an outline of the liquid ejecting head10is illustrated with a dashed-two dotted line. The outline of the liquid ejecting head10in a plan view when viewed in the Z1direction as the ejecting direction includes a center portion81and projecting portions82and83. The projecting portion82protrudes in the Y2direction from the center portion81when viewed in the Z-axis direction. The projecting portion83protrudes in the Y1direction from the center portion81when viewed in the Z-axis direction.

In the multiple liquid ejecting heads10arrayed in the Y-axis direction, the projecting portion82of the liquid ejecting head10positioned in the Y1direction and the projecting portion83of the liquid ejecting head10positioned in the Y2direction are arranged to be overlapped with each other when viewed in the X-axis direction.

The arrangement of the head chips20A to20D is described with reference toFIG.4. The head chips20A and20C are arrayed adjacent to each other in the Y-axis direction. The head chips20B and20D are arrayed adjacent to each other in the Y-axis direction. The head chips20A and20C are arranged to be overlapped with each other when viewed in the Y-axis direction. The head chips20B and20D are arranged to be overlapped with each other when viewed in the Y-axis direction. The head chips20A and20C and the head chips20B and20D are not overlapped with each other when viewed in the Y-axis direction. The head chips20B and20D are positioned in the X1direction from the head chips20A and20C.

An end portion of the head chip20A in the Y2direction and an end portion of the head chip20B in the Y1direction are arranged to be overlapped with each other when viewed in the X-axis direction. A part of the nozzle row NL of the head chip20A and a part of the nozzle row NL of the head chip20B are overlapped with each other when viewed in the X-axis direction. An end portion of the head chip20B in the Y2direction and an end portion of the head chip20C in the Y1direction are arranged to be overlapped with each other when viewed in the X-axis direction. A part of the nozzle row NL of the head chip20B and a part of the nozzle row NL of the head chip20C are overlapped with each other when viewed in the X-axis direction. An end portion of the head chip20C in the Y2direction and an end portion of the head chip20D in the Y1direction are arranged to be overlapped with each other when viewed in the X-axis direction. A part of the nozzle row NL of the head chip20C and a part of the nozzle row NL of the head chip20D are overlapped with each other when viewed in the X-axis direction. An end portion of the head chip20D in the Y2direction of one liquid ejecting head10and an end portion of the head chip20A in the Y1direction of the other liquid ejecting head10are arranged to be overlapped with each other when viewed in the X-axis direction. A part of the nozzle row NL of the head chip20D of the one liquid ejecting head10and a part of the nozzle row NL of the head chip20A of the other liquid ejecting head10are overlapped with each other when viewed in the X-axis direction.

In the head chip20A, the ink supply port46A is arranged in the end portion in the Y2direction, and the ink discharge port47A is arranged in the end portion in the Y1direction. In the head chip20B, the ink discharge port47B is arranged in the end portion in the Y2direction, and the ink supply port46B is arranged in the end portion in the Y1direction. In the head chip20C, the ink supply port46C is arranged in the end portion in the Y2direction, and the ink discharge port47C is arranged in the end portion in the Y1direction. In the head chip20D, the ink discharge port47D is arranged in the end portion in the Y2direction, and the ink supply port46D is arranged in the end portion in the Y1direction.

In the head chips20A and20B adjacent to each other in the X-axis direction, the ink supply ports46A and46B are arranged in positions close to each other. In the Y-axis direction, the ink supply ports46A and46B are arranged in positions close to each other. The ink supply port46A is arranged in a position closer to the ink supply port46B than to the ink discharge port47B.

In the head chips20B and20C adjacent to each other in the X-axis direction, the ink discharge ports47B and47C are arranged in positions close to each other. In the Y-axis direction, the ink discharge ports47B and47C are arranged in close positions. The ink discharge port47B is arranged in a position closer to the ink discharge port47C than to the ink supply port46C.

In the head chips20C and20D adjacent to each other in the X-axis direction, the ink supply ports46C and46D are arranged in positions close to each other. In the Y-axis direction, the ink supply ports46C and46D are arranged in close positions. The ink supply port46C is arranged in a position closer to the ink supply port46D than to the ink discharge port47D.

The head chips20B and20C are arranged to be overlapped with the center portion81when viewed in the Z-axis direction. The end portion of the head chip20A in the Y2direction is arranged to be overlapped with the center portion81in the Z-axis direction. The end portion of the head chip20A in the Y1direction is arranged to be overlapped with the projecting portion83when viewed in the Z-axis direction. The end portion of the head chip20D in the Y1direction is arranged to be overlapped with the center portion81when viewed in the Z-axis direction. The end portion of the head chip20D in the Y2direction is arranged to be overlapped with the projecting portion82when viewed in the Z-axis direction.

A structure inside the head chip20is described with reference toFIG.7.FIG.7is a cross-sectional view illustrating a cross-section along an XZ-plane of the head chip20. The XZ-plane is a plane along the X-axis direction and the Z-axis direction. The head chip20includes the common liquid chamber R, a relay flow channel42, the pressure chamber C, a communication flow channel44, a piezoelectric element50, and the nozzle N. The head chip20includes a nozzle plate21, a compliance substrate23, a communication plate24, a pressure chamber forming plate25, a vibration plate26, a sealing plate27, and a case28.

The thickness direction of the nozzle plate21, the compliance substrate23, the communication plate24, the pressure chamber forming plate25, the vibration plate26, the sealing plate27, and the case28is along the Z-axis direction. The nozzle plate21, the communication plate24, the pressure chamber forming plate25, the vibration plate26, and the sealing plate27are layered in this order in the Z-axis direction. The compliance substrate23is positioned on an outer side of the nozzle plate21in the X-axis direction. The compliance substrate23is positioned in the Z1direction from the communication plate24.

The nozzle plate21extends in the Y-axis direction and has a predetermined length. In the nozzle plate21, the multiple nozzles N are formed. The nozzles N are holes penetrating the nozzle plate21in the plate thickness direction thereof. The multiple nozzles N form the nozzle row NL arrayed in the Y-axis direction. The multiple nozzle rows NL are away from each other in the X-axis direction.

In the communication plate24, a part of the common liquid chamber R, the relay flow channel42, and the communication flow channel44are formed. A portion of the common liquid chamber R in the Z1direction is formed in the communication plate24. The communication flow channel44communicates with each nozzle N. The multiple communication flow channels44communicate with the respective multiple nozzles N. The nozzle plate21is arranged in the Z1direction from the communication plate24. The nozzles N are arranged in the Z1direction from the corresponding communication flow channels44. The communication plate24is formed of silicon or metal such as stainless steel, for example.

The compliance substrate23is formed to cover an opening portion formed in the communication plate24. A space of the opening portion formed in the communication plate24is included in the common liquid chamber R. The compliance substrate23is supported by the fixing plate11with a support plate22arranged therebetween. The support plate22is formed to surround the common liquid chamber R and the relay flow channel42when viewed in the Z-axis direction. The support plate22is formed of metal such as stainless steel, for example. In the Z-axis direction, a clearance is formed between the common liquid chamber R and the fixing plate11. The compliance substrate23is formed of a flexible member such as a resin film and a metallic thin plate and is modified in the Z1direction and the Z2direction to be close to and away from the fixing plate11to reduce a pressure variation of the ink in the common liquid chamber R.

The pressure chamber forming plate25is positioned in the Z2direction from the communication plate24. In the pressure chamber forming plate25, the multiple pressure chambers C are formed. The multiple pressure chambers C are formed for the respective multiple nozzles N. The pressure chambers C each communicate with the relay flow channel42and the communication flow channel44.

The vibration plate26is arranged in the Z2direction from the pressure chamber forming plate25. The vibration plate26forms wall surfaces of the pressure chambers C in the Z2direction. On a surface of the vibration plate26in the Z2direction, the multiple piezoelectric elements50are arranged. The multiple piezoelectric elements50are provided for the respective multiple pressure chambers C. Each piezoelectric element50includes multiple electrodes and a piezoelectric body layer arranged between the electrodes.

In the Z2direction from the vibration plate26, the sealing plate27is arranged. The sealing plate27covers the multiple piezoelectric elements50. The sealing plate27reinforces the vibration plate26and also protects the multiple piezoelectric elements50.

In the case28, a part of the common liquid chamber R is formed. In the common liquid chamber R, a portion in the Z2direction is formed in the case28, and a portion in the Z1direction is formed in the communication plate24. In the case28, the ink supply port46and the ink discharge port47are formed. As described above, the common liquid chamber R extends in the Y-axis direction and communicates with the multiple pressure chambers C commonly. As illustrated inFIG.4, the ink supply port46and the ink discharge port47are away from each other in the Y-axis direction.

As illustrated inFIG.7, the ink passes through the ink supply port46and flows into the common liquid chamber R. The ink in the common liquid chamber R passes through the relay flow channel42and flows into the pressure chamber C. The ink in the pressure chamber C passes through the communication flow channel44and is ejected from the nozzle N.

The head chip20includes the COF60. The COF is an abbreviation of a chip on film. The COF60includes a flexible wiring substrate61and a driving circuit62. The flexible wiring substrate61is a wiring substrate with flexibility. The flexible wiring substrate61is an FPC, for example. The flexible wiring substrate61may be an FFC, for example. The FPC is an abbreviation of a flexible printed circuit. The FFC is a flexible flat cable.

The piezoelectric elements50are electrically coupled with the flexible wiring substrate61through a not-illustrated lead electrode. The driving circuit62is electrically coupled with the flexible wiring substrate61. The flexible wiring substrate61is electrically coupled with the control unit30illustrated inFIG.1.

The piezoelectric elements50are electrically coupled with the control unit30. The piezoelectric elements50are driven under control of the control unit30. The piezoelectric elements50each deform the vibration plate26forming the wall surfaces of the pressure chambers C to change the inner volume in the corresponding pressure chamber C. With this, the piezoelectric element50ejects the ink in the pressure chamber C from the nozzle N. The liquid ejecting head10may have a configuration including another driving element such as a heating element instead of the piezoelectric element50.

Each head chip20of the present embodiment includes the two nozzle rows NL. The two nozzle rows NL provided in the head chip20may eject the same type of liquid or may eject different types of ink. Multiple common liquid chambers RA to RD communicating with one of the two nozzle rows NL included in each of the multiple head chips20and multiple common liquid chambers RA to RD communicating with the other one of the two nozzle rows NL included in each of the multiple head chips20may be flow channels independent from each other. That is, the liquid ejecting apparatus1may include two groups of flow channels each including the flow channel116, the flow channels117A to117D, the flow channels118A to118D, the flow channel119, the liquid container2, and the circulating mechanism110, the two groups of flow channels corresponding to the respective two nozzle rows NL. The number of the nozzle rows NL provided in the head chip20and the number of the groups of flow channels in the liquid ejecting apparatus1are arbitrary.

A posture change in the liquid ejecting head10is described with reference toFIG.8.FIG.8is a schematic diagram illustrating the liquid ejecting head10. InFIG.8, the liquid ejecting head10in a first posture P1in which the ejecting surface F1inclines with respect to a horizontal plane F0is illustrated with a solid line, and the liquid ejecting head10in a second posture P2in which the ejecting surface F1is arranged along the horizontal plane F0is illustrated with a dashed-two dotted line. A case in which the ejecting surface F1inclines with respect to the horizontal plane F0includes a case in which the ejecting surface F1crosses the horizontal plane F0and also includes a case in which the ejecting surface F1is orthogonal to the horizontal plane F0. The liquid ejecting head10can rotate and move about a rotation shaft151extending in the X-axis direction. The ejecting surface F1is a surface21awithin the nozzle plate21in which an opening of the nozzle N is formed as illustrated inFIG.7. The surface21ais a surface of the nozzle plate21on a side of the Z1direction, which is the ejecting direction in which the nozzle N ejects the ink. In other words, a surface of the nozzle plate21on the opposite side from the pressure chamber C in the Z-axis direction is the surface21a.

As illustrated inFIG.8, the posture of the liquid ejecting head10is changeable to multiple postures including the first posture P1and the second posture P2. The liquid ejecting apparatus1includes a posture change mechanism150that changes the posture of the liquid ejecting head10. The posture change mechanism150includes a bearing152that holds the rotation shaft151extending in the X-axis direction and a driving mechanism153that rotates the rotation shaft151. The bearing152rotatably supports the rotation shaft151. The driving mechanism153includes a motor, for example. The rotation shaft151is coupled with the carriage5holding the liquid ejecting head10.

In the first posture P1and the second posture P2, the rotation shaft151may be in the same position or may be in different positions. The posture change in the liquid ejecting head10from the first posture P1to the second posture P2may include a linear movement of the liquid ejecting head10. The liquid ejecting apparatus1can linearly move the bearing152holding the rotation shaft151. For example, the rotation shaft151and the bearing152can be moved linearly with a rack and pinion. The liquid ejecting head10can be linearly moved by using another ball screw, a guide groove, an actuator, a belt mechanism, or the like.

The liquid ejecting apparatus1executes the recording operation by the liquid ejecting head10in the first posture P1and executes the circulating operation in the second posture P2. The “recording operation” is to eject the ink from the nozzle N to apply the ink to the medium and record a letter, an image, and the like. A printing operation is an example of the recording operation. The liquid ejecting apparatus1can collect and circulate the ink that is not ejected from the nozzle N during the execution of the recording operation.

In the first posture P1of the liquid ejecting head10, the ejecting surface F1crosses the horizontal plane F0. In the present embodiment, in the first posture P1, the ejecting surface F1and the horizontal plane F0cross each other substantially perpendicularly. To be more specific, in the present embodiment, an angle θ1made by the ejecting surface F1and the horizontal plane F0in the first posture P1is 90 degrees. “Substantially perpendicularly” includes orthogonally. A case in which the angle θ1made by the ejecting surface F1and the horizontal plane F0in the first posture P1is equal to or more than 80 degrees and equal to or less than 100 degrees may be the case in which the ejecting surface F1and the horizontal plane F0cross each other “substantially perpendicularly”. The angle θ1in the first posture P1may be an angle smaller than 80 degrees and may be 30 degrees, 45 degrees, or 60 degrees, for example. In the liquid ejecting head10in such a first posture P1, the ink is ejected from the nozzle N and the recording operation is executed.

An angle θ2made by the ejecting surface F1and the horizontal plane F0in the second posture P2of the liquid ejecting head10is smaller than the angle θ1. In the present embodiment, in the second posture P2, the ejecting surface F1is substantially parallel to the horizontal plane F0. To be more specific, in the present embodiment, in the second posture P2, the ejecting surface F1is parallel to the horizontal plane F0. “Substantially parallel” includes parallel. A case in which the angle θ2in the second posture P2is equal to or more than −10 degrees and equal to or less than +10 degrees may be the case in which the ejecting surface F1and the horizontal plane F0are “substantially parallel” to each other. The angle θ2is, for example, a rotation angle about the X-axis, and a clockwise rotation is positive while a counterclockwise rotation is negative. In the angle θ2, a clockwise rotation may be positive while a counterclockwise rotation may be negative. InFIG.8, since the ejecting surface F1is arranged along the horizontal plane F0in the second posture P2, the angle θ2is not illustrated. The angle θ2is not limited to 0 degrees and may be a value greater than 0 degrees. The angles θ1and θ2may be an angle that is the smaller one of the angles made by the horizontal plane F0and the ejecting surface F1. A difference between the angle θ1and the angle θ2may be equal to or more than 5 degrees or equal to or less than 90 degrees, for example.

The circulating operation performed in the second posture P2includes a filling operation to fill the liquid ejecting head10with the ink, for example. The filling operation to fill the liquid ejecting head10with the ink includes an operation to fill the multiple head chips20and the flow channels116,117A to117D,118A to118D, and119with the ink. This filling operation is performed before the first use of the liquid ejecting head10, for example. For example, the filling operation is also performed after replacement of the liquid ejecting head10. The filling operation is performed before using the liquid ejecting head10after a periodic inspection of the liquid ejecting head10. The filling operation is performed after maintenance such as ink replacement and cleaning of the inside of the flow channel. The filling operation may include refilling of the ink. Such a filling operation may be referred to as “initial filling”.

The circulating operation performed in the second posture P2includes a cleaning operation of the liquid ejecting head10. In the cleaning operation, the ink is circulated. In the cleaning operation, another cleaning liquid may be circulated. The cleaning operation is periodically performed, for example. The cleaning operation may be executed when the time of the recording operation exceeds a certain period of time, for example. The cleaning operation may be executed after the liquid ejecting apparatus1is powered on. The cleaning operation may be executed before or after the recording operation. The cleaning operation may be executed when occurrence of abnormality in the liquid ejecting head10is detected.

The circulating operation is not limited to the filling operation and the cleaning operation. The circulating operation may include another operation to circulate the ink in a state where the recording operation is not executed. Another maintenance operation may be executed during the circulating operation.

In the circulating operation, as described above, the ink in the sub tank111flows inside the ink supply flow channel114and is supplied to the liquid ejecting head10. The ink discharged from the liquid ejecting head10flows inside the ink discharge flow channel115and is collected into the sub tank111.

In the circulating operation, the ink introduced in the liquid ejecting head10flows inside the flow channel116and the flow channels117A to117D and is supplied to the head chips20A to20D. The ink discharged from the head chips20A to20D flow inside the flow channels118A to118D and the flow channel119and is discharged into the ink discharge flow channel115.

In the circulating operation, the ink introduced in the head chips20A to20D passes through the ink supply port46and is supplied into the common liquid chamber R. The ink supplied in the common liquid chamber R flows inside the common liquid chamber R in the Y-axis direction. The ink flowing inside the common liquid chamber R passes through the ink discharge port47and is discharged from the head chips20A to20D. The ink discharged from the head chips20A to20D flows into the flow channels118A to118D. The ink flowing through the common liquid chamber R of the head chips20A to20D is collected into the sub tank111as described above. The ink is thus circulated.

The control unit30controls the circulating mechanism110. The control unit30executes the circulating operation by controlling the pump112. The control unit30can execute the posture change in the liquid ejecting head10by controlling the posture change mechanism150. The control unit30can change the liquid ejecting head10into the first posture P1or the second posture P2by controlling the driving mechanism153.

FIG.9is a side view illustrating the head chip20in the first posture P1. In the head chip20A and the head chip20C in the first posture P1, the positions of the ink discharge ports47with respect to the ink supply ports46are the same; for this reason, either of the head chips20A and20C in the first posture P1is illustrated inFIG.9for the sake of convenience. In the head chip20A in the first posture P1, the ink discharge port47A is positioned below the ink supply port46A in the gravity direction G1. In the head chip20C in the first posture P1, the ink discharge port47C is positioned below the ink supply port46C in the gravity direction G1. In the head chips20A and20C in the first posture P1, the ink flowing in the common liquid chambers RA and RC flows downward in the gravity direction G1. In the present embodiment, the ink in the common liquid chamber R flows along the Y-axis, and the Y-axis in the first posture P1is parallel to the gravity direction G1; accordingly, the ink flowing in the common liquid chambers RA and RC flows in the gravity direction G1. The gravity direction G1is an example of a “first flow direction”. The Y1direction in the first posture P1that is the same direction as the gravity direction G1is also an example of the “first flow direction”. In this case, “downward in the gravity direction G1” indicates facing downward with respect to the horizontal plane F0while the gravity direction G1is a downward direction and the opposite direction to the gravity direction G1is an upward direction, and it is not limited to only the gravity direction G1. Likewise, “upward in the gravity direction G1” indicates facing upward with respect to the horizontal plane F0, and it is not limited to only the opposite direction to the gravity direction G1.

Although it is not illustrated inFIG.9, the head chips20B and20D in the first posture P1are flipped vertically with respect to the head chips20A and20C. In the head chip20B in the first posture P1, the ink supply port46B is positioned below the ink discharge port47B in the gravity direction G1. In the head chip20D in the first posture P1, the ink supply port46D is positioned below the ink discharge port47D in the gravity direction G1. In the head chips20B and20D in the first posture P1, the ink flowing in the common liquid chambers RB and RD flows upward in the gravity direction G1. In the present embodiment, the ink in the common liquid chamber R flows along the Y-axis, and the Y-axis in the first posture P1is parallel to the gravity direction G1; accordingly, the ink flowing in the common liquid chambers RB and RD flows in the opposite direction to the gravity direction G1. The Y2direction in the first posture P1that is the opposite direction to the gravity direction G1is an example of a “second flow direction”.

FIG.10is a side view illustrating the head chip20in the second posture P2. In the head chip20A and the head chip20C in the second posture P2, the positions of the ink discharge ports47with respect to the ink supply ports46are the same; for this reason, either of the head chips20A and20C in the second posture P2is illustrated inFIG.10for the sake of convenience. In the head chips20A and20C in the second posture P2, the ink supply ports46A and46C and the ink discharge ports47A and47C are arranged in the same positions in the gravity direction G1. In the head chips20A and20C in the second posture P2, the ink flowing in the common liquid chambers RA and RC flows in the Y1direction in the second posture P2along the horizontal plane F0.

Although it is not illustrated inFIG.10, the head chips20B and20D in the second posture P2are flipped horizontally with respect to the head chips20A and20C. For example, when viewed in the X1direction, the Y1direction is right, and the Y2direction is left. In the head chips20B and20D in the second posture P2, the ink supply ports46B and46D and the ink discharge ports47B and47D are arranged in the same positions in the gravity direction G1. In the head chips20B and20D in the second posture P2, the ink flowing in the common liquid chambers RB and RD flows in the Y2direction in the second posture P2along the horizontal plane F0.

Such a liquid ejecting apparatus1includes the liquid ejecting head10including the ejecting surface F1to eject the ink, the sub tank111that reserves the ink to be supplied to the liquid ejecting head10, the circulating mechanism110that executes the circulating operation to circulate the ink between the liquid ejecting head10and the sub tank111, and the control unit30that controls the circulating mechanism110. The control unit30executes the recording operation by the liquid ejecting head10in the first posture P1in which the ejecting surface F1crosses the horizontal plane F0and executes the circulating operation in the second posture P2in which the angle made by the ejecting surface F1and the horizontal plane F0is smaller than that in the first posture P1.

The liquid ejecting apparatus1in the present embodiment executes the circulating operation in the second posture P2; for this reason, the flow direction of the ink in the common liquid chamber R is a direction at a smaller angle with respect to the horizontal plane F0than that of the first posture P1. With this, the air bubbles are more likely to be discharged from the common liquid chamber R than a case of executing the circulating operation in the first posture P1. Thus, a risk that the air bubbles remain in the common liquid chamber R after the circulating operation is reduced, and a risk of causing an ejection failure because the air bubbles in the common liquid chamber R are drawn into the nozzle N and the pressure chamber C during the subsequent recording operation is suppressed. As a result, the reliability of the recording operation in the liquid ejecting head10is improved.

For example, in the head chips20A and20C in the first posture P1illustrated inFIG.9, the Y1direction in which the ink flows in the common liquid chambers RA and RC is the gravity direction G1. The buoyancy acting on the air bubbles in the common liquid chambers RA and RC is in the opposite direction to the gravity direction G1. Therefore, the air bubbles in the common liquid chambers RA and RC are less likely to be discharged from the ink discharge ports47A and47C if the ink circulating operation is executed on such head chips20A and20C in the first posture P1. On the other hand, in the liquid ejecting apparatus1, the circulating operation is executed in the second posture P2as illustrated inFIG.10; for this reason, the buoyancy of the air bubbles acting in the opposite direction to the Y1direction in which the ink flows in the common liquid chambers RA and RC of the head chips20A and20C is smaller than that of the first posture P1, and thus the air bubbles in the common liquid chamber R are likely to be discharged from the ink discharge port47.

The circulating operation performed in the second posture P2includes the filling operation to fill the liquid ejecting head10with the ink. In the liquid ejecting head10in the second posture P2, the liquid ejecting head10can be filled with the ink while circulating the ink. With this, the air bubbles in the common liquid chamber R can be discharged to the outside of the liquid ejecting head10while filling the common liquid chamber R with the ink. Therefore, the risk that the air bubbles remain in the common liquid chamber R is reduced. The risk that the air bubbles in the common liquid chamber R are drawn into the nozzle N or the pressure chamber C during the subsequent recording operation is suppressed.

The circulating operation performed in the second posture P2includes the cleaning operation of the liquid ejecting head10. In the liquid ejecting head10of the second posture P2, the cleaning operation can be executed while circulating the ink. With this, the air bubbles in the common liquid chamber R can be discharged to the outside of the liquid ejecting head10while the flow channel of the ink in the liquid ejecting apparatus1is cleaned. Therefore, the risk that the air bubbles remain in the common liquid chamber R is reduced. The risk that the air bubbles in the common liquid chamber R are drawn into the nozzle N or the pressure chamber C during the subsequent recording operation is suppressed. For example, the air bubbles can be discharged from the inside of the common liquid chamber R by executing the cleaning operation periodically. With the cleaning operation being executed when abnormality of the liquid ejecting head10is detected, the state of the ink in the flow channel can be improved and also the air bubbles can be discharged from the inside of the common liquid chamber R. For example, the viscosity of the ink may be improved by executing the cleaning operation.

In the second posture P2, the ejecting surface F1is substantially parallel to the horizontal plane F0. With this, the flow direction of the ink in the common liquid chamber R is along the horizontal plane F0, and thus the air bubbles are likely to be discharged from the common liquid chamber R. In the liquid ejecting apparatus1, since the ejecting surface F1is substantially parallel to the horizontal plane F0in the second posture P2, the performance of discharging the air bubbles can be uniform in the multiple head chips20A to20D.

The liquid ejecting head10includes the head chip20A and the head chip20B. In this case, the head chip20A is an example of a “first head chip”, and the head chip20B is an example of a “second head chip”.

The head chip20A includes the common liquid chamber RA communicating with multiple nozzles NA, the ink supply port46A to introduce the ink to the common liquid chamber RA, and the ink discharge port47A to discharge the ink from the common liquid chamber RA. The ink supply port46A is an example of a “first supply port”, and the ink discharge port47A is an example of a “first discharge port”.

The head chip20B includes the common liquid chamber RB communicating with multiple nozzles NB, the ink supply port46B to introduce the ink to the common liquid chamber RB, and the ink discharge port47B to discharge the ink from the common liquid chamber RB. The ink supply port46B is an example of a “second supply port”, and the ink discharge port47B is an example of a “second discharge port”.

The head chips20A and20B are arranged such that, in the first posture P1, the first flow direction in which the ink flows from the ink supply port46A to the ink discharge port47A and the second flow direction in which the ink flows from the ink supply port46B to the ink discharge port47B are opposite to each other. As illustrated inFIG.4, the first flow direction is the Y1direction, and the second flow direction is the Y2direction. The Y1direction is the opposite direction to the Y2direction. The same applies to the head chips20C and20D. In the liquid ejecting apparatus1in the first posture P1, the first flow direction and the second flow direction cross an extending direction of an intersection line of the ejecting surface F1and the horizontal plane F0. In the present embodiment, the extending direction of the intersection line of the ejecting surface F1and the horizontal plane F0is the X-axis direction. As illustrated inFIG.8, the extending direction of the intersection line of the ejecting surface F1and the horizontal plane F0in the first posture P1is the X-axis direction.

The first flow direction and the second flow direction are directions along the ejecting surface F1. As illustrated inFIG.9, the ejecting surface F1is along an XY plane. The XY plane is a plane along the X-axis direction and the Y-axis direction. The first flow direction and the second flow direction are along the Y-axis direction. As illustrated inFIG.3, the direction in which the nozzle row NL extends is the Y-axis direction.

As illustrated inFIG.4, in the liquid ejecting head10, the head chip20A and the head chip20B are adjacent to each other, and the ink supply port46A is arranged closer to the ink supply port46B than to the ink discharge port47B.

In the liquid ejecting head10, the head chip20B and the head chip20C are adjacent to each other, and the ink discharge port47B is arranged closer to the ink discharge port47C than to the ink supply port46C.

In the liquid ejecting head10, the head chip20C and the head chip20D are adjacent to each other, and the ink supply port46C is arranged closer to the ink supply port46D than to the ink discharge port47D.

In the liquid ejecting heads10adjacent to each other in the Y-axis direction, the head chip20D of one liquid ejecting head10and the head chip20A of the other liquid ejecting head10are adjacent to each other, and the ink discharge port47D of the one liquid ejecting head10is arranged closer to the ink discharge port47A of the other liquid ejecting head10than to the ink supply port46A thereof.

According to the liquid ejecting apparatus1including such a liquid ejecting head10, the ink supply ports46A to46D are arranged close to each other, and the ink discharge ports47A to47D are arranged close to each other; thus, a variation in the ink weight ejected from the nozzles N of the adjacent head chips20is reduced. With this, although the directions of the ink flows in the common liquid chambers R of the adjacent head chips20are opposite directions, the air bubbles can be discharged uniformly from the common liquid chambers R of the adjacent head chips20by executing the circulating operation in the second posture P2.

A first posture P3of the liquid ejecting head10according to Modification 1 is described with reference toFIG.11.FIG.11is a side view illustrating the first posture P3of the head chip20according to Modification 1. InFIG.11, the head chips20A and20C in the first posture P3are illustrated. The head chip20in the first posture P3according to Modification 1 is inclined at an angle θ3different from that of the head chip20in the first posture P1according to Embodiment 1. The angle θ3made by the ejecting surface F1and the horizontal plane F0in the first posture P3may be 45 degrees, for example. The angle θ3is an angle greater than the angle θ2and is an angle smaller than the angle θ1. Thus, the angle θ3in the first posture P3may be an angle smaller than 90 degrees.

A second posture P4of the liquid ejecting head10according to Modification 2 is described with reference toFIG.12.FIG.12is a side view illustrating the head chip20in the second posture P4according to Modification 2. InFIG.12, the head chips20A and20C in the second posture P4are illustrated. The head chip20in the second posture P4according to Modification 2 is inclined at an angle θ4different from that of the head chip20in the second posture P2according to Embodiment 1. The angle θ4made by the ejecting surface F1and the horizontal plane F0in the second posture P4may be 10 degrees, for example. The angle θ4may be an angle greater than the angle θ2and may be an angle smaller than the angle θ3. Thus, the angle θ4in the second posture P4may be an angle greater than 0 degrees. In the liquid ejecting apparatus1according to the modification, the circulating operation can be executed in the head chip20in the second posture P4. When the angle θ4is smaller than the angles θ1and θ3, the air bubbles in the common liquid chamber R are likely to be discharged more with the head chip20in the second posture P4than that in the first posture P1or P3.

A liquid ejecting head10B according to Embodiment 2 is described.FIG.13is a bottom view illustrating the liquid ejecting head10B according to Embodiment 2. The liquid ejecting head10B illustrated inFIG.13illustrates a bottom view in a state of the first posture P1.FIG.13illustrates a V-axis direction and a W-axis direction. The V-axis direction and the W-axis direction are directions crossing each other when viewed in the Z-axis direction. The V-axis direction is inclined at a predetermined angle with respect to the Y-axis direction. The V-axis direction includes a V1direction and a V2direction that are directions opposite to each other. The W-axis direction is inclined at a predetermined angle α with respect to the X-axis direction. The W-axis direction includes a W1direction and a W2direction.

A liquid ejecting apparatus1B according to Embodiment 2 includes the multiple liquid ejecting heads10B. The liquid ejecting apparatus1B according to Embodiment 2 is different from the liquid ejecting apparatus1according to Embodiment 1 in that the liquid ejecting apparatus1B according to Embodiment 2 includes the liquid ejecting head10B instead of the liquid ejecting head10. In the descriptions of Embodiment 2, a similar description as that of Embodiment 1 may be omitted.

The liquid ejecting head10B includes multiple head chips20E and20F. The head chips20E and20F extend in the V-axis direction. The head chips20E and20F each include the multiple nozzles N. The multiple nozzles N form the nozzle row NL arrayed in the V-axis direction. Although it is not illustrated, common liquid chambers RE and RF of the head chips20E and20F extend in the V-axis direction and communicate with the multiple nozzles N commonly. That is, the ink in the common liquid chambers RE and RF flows along the V-axis.

The head chip20E and the head chip20F are arranged alternately in the X-axis direction. The head chip20E includes an ink supply port46E and an ink discharge port47E communicating with the common liquid chamber RE. The head chip20F includes an ink supply port46F and an ink discharge port47F communicating with the common liquid chamber RF.

The ink supply port46E is positioned in the Y2direction from the ink discharge port47E. The ink discharge port47F is positioned in the Y2direction from the ink supply port46F.

As with Embodiment 1, the Y1direction is along the gravity direction G1in the first posture P1of the liquid ejecting head10B of the present embodiment. In the first posture P1of the liquid ejecting head10B, the ink in the common liquid chamber RE of the head chip20E flows in the gravity direction G1, in other words, flows downward in the gravity direction G1when viewed in the X-axis direction. Specifically, in the first posture P1of the liquid ejecting head10B, the ink in the common liquid chamber RE of the head chip20E flows along the V1direction in the first posture P1. In the first posture P1of the liquid ejecting head10B, the ink in the common liquid chamber RF of the head chip20F flows in the opposite direction to the gravity direction G1, in other words, flows upward in the gravity direction G1when viewed in the X-axis direction. Specifically, in the first posture P1of the liquid ejecting head10B, the ink in the common liquid chamber RF of the head chip20F flows in the V2direction in the first posture P1.

As with Embodiment 1, the Y-axis direction is arranged along the horizontal plane F0in the second posture P2of the liquid ejecting head10B in the present embodiment. The horizontal plane F0is illustrated inFIG.10. In the second posture P2of the liquid ejecting head10B, the ejecting surface F2is along the horizontal plane F0. The flows of the ink in the common liquid chambers RE and RF in the head chips20E and20F are along the horizontal plane F0.

The liquid ejecting apparatus1B including such a liquid ejecting head10B also executes the recording operation in the first posture P1and executes the circulating operation in the second posture P2. The liquid ejecting apparatus1B according to Embodiment 2 also achieves effects and operations similar to that of the liquid ejecting apparatus1of Embodiment 1.

A liquid ejecting apparatus1C according to Embodiment 3 is described with reference toFIG.14.FIG.14is a schematic diagram illustrating an ink flow channel in the liquid ejecting apparatus1C according to Embodiment 3. The liquid ejecting apparatus1C of Embodiment 3 is different from Embodiment 1 illustrated inFIG.1in that the liquid ejecting apparatus1C of Embodiment 3 includes a blocking member121, a negative pressure generating unit122, and a tank123.

The liquid ejecting apparatus1C includes the blocking member121. The blocking member121is in a plate shape, for example, and blocks the multiple nozzles N formed in the ejecting surface F1. The blocking member121can be brought into contact with the ejecting surface F1. The blocking member121may be formed of rubber, for example, or may be formed of another material. The blocking member121may have a structure including multiple projecting portions insertable to the multiple nozzles N. For example, the blocking member121and the ejecting surface F1can be in contact with each other by the liquid ejecting head10being moved. The blocking member121may be in contact with the ejecting surface F1by being moved.

The liquid ejecting apparatus1C includes the negative pressure generating unit122. The negative pressure generating unit122of the present embodiment is coupled to the sub tank111and can make the pressure in the sub tank111negative. The negative pressure generating unit122may have a similar configuration as that of the pressure adjusting unit111bof Embodiment 1. The negative pressure generating unit122includes a compressor, for example. The negative pressure generating unit122may be directly coupled to the sub tank111or may be coupled to the sub tank111through another flow channel. The negative pressure generating unit122may be provided in the middle of the ink discharge flow channel115, not the sub tank111. The negative pressure generating unit122is not limited to a compressor and may be another sucking pump such as a tube pump, a syringe pump, and a diaphragm pump.

The liquid ejecting apparatus1C includes the tank123. The tank123is coupled between the pump112and the temperature adjusting unit113, for example. The tank123temporarily reserves the ink. The ink in the tank123is supplied to the liquid ejecting head10through the ink supply flow channel114. The tank123may be coupled between the temperature adjusting unit113and the liquid ejecting head10.

The liquid ejecting apparatus1C includes a check valve138. The check valve138is provided in the ink supply flow channel114between the sub tank111and the pump112. The check valve138can prevent a backflow of the ink from the pump112toward the sub tank111. With this, the pressure in the liquid ejecting head10can be made negative effectively through the sub tank111by driving the negative pressure generating unit122.

The liquid ejecting apparatus1C may not include the check valve138. The liquid ejecting apparatus1C may have a configuration including an opening/closing valve instead of the check valve138. The backflow of the ink into the sub tank111may be prevented by closing the opening/closing valve when the negative pressure generating unit122is driven, or the pump112may be capable of preventing the backflow of the ink to the sub tank111. For example, the backflow of the ink to the sub tank111can be prevented by the pump112that is a tube pump.

Such a liquid ejecting apparatus1C according to Embodiment 3 includes the blocking member121that can be brought into contact with the ejecting surface F1. The liquid ejecting head10includes a filter136A arranged upstream of the ink supply port46A and a filter136B arranged upstream of the ink supply port46B. The filter136A is an example of a “first filter”, and the filter136B is an example of a “second filter”.

A circulating mechanism110B includes the negative pressure generating unit122arranged downstream of the ink discharge ports47A and47B.

The circulating operation in the second posture P2includes an operation to make the pressures inside the common liquid chambers RA and RB negative through the ink discharge ports47A and47B by driving the negative pressure generating unit122while blocking the multiple nozzles N with the blocking member121.

According to such a liquid ejecting apparatus1C, the filters136A to136D are provided in the head chips20A to20D, respectively, to be a resistance to the flow of the ink, and also the multiple nozzles N are blocked by the blocking member121; thus, the insides of the common liquid chambers RA to RD can be efficiently depressurized by driving the negative pressure generating unit122. With this, the sizes of the air bubbles in the common liquid chambers RA to RD can be increased, and such air bubbles with increased volumes are likely to be drawn toward the ink discharge port47. The air bubbles with large volumes are more likely to be drawn by the negative pressure generating unit122than the air bubbles with small volumes are. Therefore, the air bubbles are likely to be discharged from the common liquid chambers RA to RD.

The control unit30does not perform pressurization from upstream of the head chips20A to20D during the circulating operation in the second posture P2. Upstream of the head chips20A to20D includes upstream of the liquid ejecting head10. Upstream of the liquid ejecting head10includes the ink supply flow channel114between the sub tank111and the liquid ejecting head10. The control unit30does not performs the pressurization by the pump112provided upstream of the head chips20A to20D during the circulating operation in the second posture P2. With this, the ink flowing in from upstream of the head chips20A to20D is reduced more than a case of performing the circulating operation while pressurizing the pump112, and thus the insides of the common liquid chambers RA to RD are likely to be depressurized. Therefore, with the volumes of the air bubbles in the common liquid chambers RA to RD being increased, the air bubbles are likely to be drawn to a side close to the negative pressure generating unit122and are likely to be discharged from the common liquid chambers RA to RD.

In the liquid ejecting apparatus1C, there are no filters between the ink discharge port47A to47D and the negative pressure generating unit122. In the liquid ejecting head10, the filters136A to136D are arranged upstream of the head chips20A to20D, and there are no filters downstream of the head chips20A to20D. The filter136is not provided in each of the flow channels118A to118D, the flow channel119, and the ink discharge flow channel115. If there are the filters136A to136D between the ink discharge ports47A to47D and the negative pressure generating unit122, the insides of the common liquid chambers RA to RD are less likely to be depressurized; however, since there are no filters in the flow channels between the ink discharge ports47A to47D and the negative pressure generating unit122in the liquid ejecting apparatus1C, the common liquid chambers RA to RD are likely to be depressurized by the negative pressure generating unit122. As a result, with the liquid ejecting apparatus1C, the air bubbles in the common liquid chambers RA to RD are likely to be discharged.

A liquid ejecting apparatus1G according to Embodiment 4 is described with reference toFIGS.15and16.FIG.15is a side view illustrating the first posture P1of a head chip20G according to Embodiment 4.FIG.16is a side view illustrating the second posture P2of the head chip20G according to Embodiment 4. The liquid ejecting apparatus1G includes a liquid ejecting head10G including the multiple head chips20G. The liquid ejecting apparatus1G is different from the liquid ejecting apparatus1according to Embodiment 1 in that the liquid ejecting apparatus1G includes the liquid ejecting head10G including the head chips20G instead of the liquid ejecting head10including the head chips20A to20D. In the descriptions of the liquid ejecting apparatus1G according to Embodiment 4, similar descriptions as that of Embodiment 1 may be omitted.

The liquid ejecting head10G may have a configuration including the single head chip20G or may have a configuration including the multiple head chips20G. Each head chip20G includes a common liquid chamber RG communicating with the multiple nozzles N commonly. The configuration of the head chip20G is substantially the same as that of the head chip20illustrated inFIG.7except a supply port46G, discharge ports47G and47H, and the common liquid chamber RG.

As illustrated inFIGS.15and16, the head chip20G includes the supply port46G, the discharge port47G, and the discharge port47H. Those supply port46G, discharge port47G, and discharge port47H communicate with the common liquid chamber RG. The supply port46G is coupled with an ink supply flow channel. The discharge ports47G and47H are coupled with an ink discharge flow channel. The ink in the ink supply flow channel is supplied to the inside of the common liquid chamber RG from the supply port46G. The ink in the common liquid chamber RG is discharged from the discharge ports47G and47H and flows into the ink discharge flow channel.

The supply port46G is positioned between the discharge port47G and the discharge port47H in the Y-axis direction. The discharge port47G is positioned in the Y2direction from the supply port46G. The discharge port47H is positioned in the Y1direction from the supply port46G.

A part of the ink flowing from the supply port46G flows inside the common liquid chamber RG in the Y2direction and is discharged from the discharge port47G. A part of the ink flowing from the supply port46G flows inside the common liquid chamber RG in the Y1direction and is discharged from the discharge port47H. The liquid ejecting apparatus1G executes the recording operation in the first posture P1and executes the circulating operation in the second posture P2. The liquid ejecting apparatus1G discharges the air bubbles in the common liquid chamber RG from the discharge ports47G and47H by performing the circulating operation in the second posture P2.

The liquid ejecting apparatus1G includes the liquid ejecting head10G. The liquid ejecting head10G includes the common liquid chamber RG communicating with the multiple nozzles N, the supply port46G to introduce the ink to the common liquid chamber RG, and the discharge ports47G and47H to discharge the ink from the common liquid chamber RG. In the first posture P1, the supply port46G is arranged between the discharge port47G and the discharge port47H in the gravity direction G1. Thus, the liquid ejecting apparatus1G may have a configuration including the liquid ejecting head10G. In the liquid ejecting apparatus1G, since the circulating operation can be executed in the second posture P2, the flow of the ink in the common liquid chamber RG is along the horizontal plane F0. Therefore, the air bubbles in the common liquid chamber RG are likely to be discharged.

When the circulating operation is performed in the first posture P1illustrated inFIG.15, the ink flowing from the supply port46G flows into a center portion in the Y-axis direction and then diverges in the common liquid chamber RG. A part of the ink flowing from the supply port46G flows in the Y2direction, in other words, in the opposite direction to the gravity direction G1in the common liquid chamber RG, and a part of the rest of the ink flowing from the supply port46G flows in the Y1direction, in other words, in the gravity direction G1in the common liquid chamber RG. For example, although the air bubbles in a lower portion in the common liquid chamber RG are pushed in the Y1direction with the flow of the ink in the Y1direction, the buoyancy in the Y2direction acts on the air bubbles. Therefore, since the buoyancy in the opposite direction to the ink in the Y1direction acts on the air bubbles in the common liquid chamber RG, there is a problem that the air bubbles are less likely to be discharged from the common liquid chamber RG. For example, in the center portion of the common liquid chamber RG, there is a risk that the air bubbles accumulate in a converging portion of the ink flowing from the supply port46G. In the liquid ejecting apparatus1G according to Embodiment 4, since the circulating operation is executed in the second posture P2illustrated inFIG.16, the air bubbles in the common liquid chamber RG flow in a direction along the horizontal plane F0and are likely to be discharged from the discharge ports47G and47H.

Embodiments described above merely indicate a representative mode of the present disclosure. The present disclosure is not limited to Embodiments described above, and various changes and additions are possible without departing from the gist of the present disclosure.

In Embodiments described above, the flow direction of the ink in the common liquid chamber R in the second posture P2is described as a direction along the horizontal plane F0; however, the flow direction of the ink in the common liquid chamber R is not limited thereto. The flow of the ink in the common liquid chamber R in the second posture P2may not be along the horizontal plane F0. The flow of the ink in the common liquid chamber R in the second posture P2may include a flow in a direction not along the horizontal plane F0.

In Embodiments described above, a case in which the ink supply port46B is arranged in a position close to the ink supply port46A is exemplified; however, the arrangement of the head chips20A and20B is not limited thereto. The ink discharge port47B may be arranged in a position close to the ink supply port46A, or the ink discharge port47A may be arranged in a position close to the ink supply port46B.

In the liquid ejecting apparatus1C illustrated inFIG.14, a case in which the multiple blocking members121are arranged for the respective head chips20is described; however, a blocking member121may be arranged to be brought into contact with the ejecting surfaces F1of the multiple head chips20.

In Embodiments described above, the circulating operation may be performed during the recording operation in the first posture P1. That is, both the circulating operation in the second posture P2to discharge the air bubbles from the inside of the common liquid chamber R and circulating operation performed during the recording operation in the first posture P1may be executed.

In Embodiments described above, the serial type liquid ejecting apparatus1that reciprocates, in the width direction of the medium PA, the carriage in which the liquid ejecting head10is mounted is exemplified; however, the present disclosure may also be applied to a line type liquid ejecting apparatus including the multiple liquid ejecting heads10.

The liquid ejecting apparatus1exemplified in Embodiments described above can be employed in not only a device dedicated to printing but also various devices such as a facsimile apparatus and a copier. Application of the liquid ejecting apparatus of the present disclosure is not limited to printing. For example, a liquid ejecting apparatus that ejects a liquid solution of color material is used as a manufacturing apparatus that forms a color filter of a display apparatus such as a liquid crystal display panel. A liquid ejecting apparatus that ejects a liquid solution of conductive material is used as a manufacturing apparatus that forms wiring and an electrode of a wiring substrate. A liquid ejecting apparatus that ejects a liquid solution of an organic matter related to a living organism is used as a manufacturing apparatus that manufactures a biochip, for example.