JP2017065249A - Liquid discharge head, liquid discharge unit, and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head capable of reducing a change in characteristics of liquid inside a nozzle.SOLUTION: A liquid discharge head comprises: a nozzle 4 for discharging liquid; an individual liquid chamber 6 communicated with the nozzle 4; a nozzle passage 5, which communicates the individual liquid chamber 6 with the nozzle 4, and in which the liquid flows toward the nozzle 4; and a circulation flow passage 41 in which the liquid flows to the direction crossing the flow direction in the nozzle passage 5. An opening 41a in the circulation flow passage 41 faces the nozzle passage 5. An opening 4a at a liquid flow-in side in the nozzle 4 faces a boundary part 60 between the nozzle passage 5 and the circulation flow passage 41, and a part of the opening 4a at the liquid flow-in side faces the nozzle passage 5.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a liquid discharge head, a liquid discharge unit, and an apparatus for discharging liquid.

  As a liquid discharge head (droplet discharge head) for discharging a liquid, a circulation head that circulates liquid in a plurality of individual liquid chambers is known.

  For example, it is known that the chamber is divided into two flow paths by a barrier, the nozzle is disposed on the top wall in the longitudinal direction of the chamber, and the inner surface of the nozzle is washed away with an ink flow to keep the nozzle clean ( Patent Document 1).

Japanese Patent No. 4467858

  By the way, by circulating the liquid in the liquid discharge head, it is possible to suppress changes in the liquid characteristics due to drying or the like.

  However, in the configuration disclosed in Patent Document 1, since the nozzle is disposed in the folded portion of the two flow paths, the liquid cannot be reliably stirred up to the inside of the nozzle. There is a problem that the characteristic change cannot be reduced.

  The present invention has been made in view of the above-described problems, and an object thereof is to reduce a change in characteristics of a liquid inside a nozzle.

In order to solve the above-described problem, a liquid discharge head according to the present invention includes:
A nozzle for discharging liquid;
An individual liquid chamber leading to the nozzle;
A circulation flow path leading to the individual liquid chamber,
When the direction of the liquid flow in the individual liquid chamber is a first direction and the direction of the liquid flow in the circulation channel is a second direction,
The first direction and the second direction intersect,
The liquid inflow side opening of the nozzle is configured to face a region where the liquid flow direction changes from the first direction to the second direction.

  According to the present invention, it is possible to reduce the characteristic change of the liquid inside the nozzle.

FIG. 2 is an external perspective view illustrating an example of a liquid discharge head according to the first embodiment of the present invention. It is sectional explanatory drawing of the direction (liquid chamber longitudinal direction) orthogonal to the nozzle arrangement direction of the head. FIG. 3 is an enlarged cross-sectional explanatory view of the main part of FIG. 2. FIG. 4 is an enlarged cross-sectional explanatory view of the main part of FIG. 3. It is explanatory drawing similarly used for an effect | action description. It is explanatory drawing with which it uses for description of a comparative example. It is a principal part schematic explanatory drawing of the liquid discharge head which concerns on 2nd Embodiment of this invention. It is a principal part schematic explanatory drawing of the liquid discharge head which concerns on 3rd Embodiment of this invention. It is a principal part schematic explanatory drawing of the liquid discharge head which concerns on 4th Embodiment of this invention. FIG. 10 is a schematic explanatory diagram of a main part of a liquid ejection head according to a fifth embodiment of the present invention. It is a principal part schematic explanatory drawing of the liquid discharge head which concerns on 6th Embodiment of this invention. It is a principal part schematic explanatory drawing of the liquid discharge head which concerns on 7th Embodiment of this invention. It is a principal part schematic explanatory drawing of the liquid discharge head which concerns on 8th Embodiment of this invention. It is principal part plane explanatory drawing of an example of the apparatus which discharges the liquid which concerns on this invention. It is principal part side explanatory drawing of the apparatus. It is principal part plane explanatory drawing of the other example of the liquid discharge unit which concerns on this invention. It is front explanatory drawing of the further another example of the liquid discharge unit which concerns on this invention. It is a schematic explanatory drawing of the other example of the apparatus which discharges the liquid based on this invention. It is a plane explanatory view of the head unit of the device. FIG. 2 is a block explanatory diagram for explaining an example of a liquid circulation system in the apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An example of the liquid discharge head according to the first embodiment of the present invention will be described with reference to FIGS. 1 is an external perspective view of the liquid discharge head, FIG. 2 is a cross-sectional explanatory view in a direction (liquid chamber longitudinal direction) orthogonal to the nozzle arrangement direction of the head, and FIG. 3 is an enlarged cross-sectional explanatory view of the main part of FIG. It is.

  In the liquid discharge head, a nozzle plate 1, a flow path plate 2, and a diaphragm 3 as a wall surface member are laminated and joined. And the piezoelectric actuator 11 which displaces the diaphragm 3, the frame member 20 as a common liquid chamber member, and the cover 21 are provided.

  The nozzle plate 1 has a plurality of nozzles 4 for discharging liquid, and here has two nozzle rows in which a plurality of nozzles 4 are arranged.

  The flow path plate 2 includes a nozzle passage 5 that communicates with the nozzle 4, an individual liquid chamber 6 that communicates with the nozzle passage 5, a supply flow path side fluid resistance section 7 that communicates with the individual liquid chamber 6, and a liquid introduction section that communicates with the supply flow path side fluid resistance section 7. (Passage) A through hole and a groove forming 8 are formed. The supply flow path side fluid resistance section 7 and the liquid introduction section 8 constitute a liquid supply flow path.

  The diaphragm 3 is a deformable wall member that forms the wall surface of the individual liquid chamber 6 of the flow path plate 2.

  A piezoelectric actuator 11 including an electromechanical conversion element as a driving means (actuator means, pressure generating means) for deforming the diaphragm 3 is disposed on the opposite side of the diaphragm 3 from the individual liquid chamber 6.

  The piezoelectric actuator 11 is formed by grooving a laminated piezoelectric member by half-cut dicing to form a required number of columnar piezoelectric elements (piezoelectric columns) 12 in a comb-teeth shape at predetermined intervals along the nozzle arrangement direction. . The piezoelectric element 12 is bonded to the diaphragm 3.

  The frame member 20 is formed with a common liquid chamber 10 to which liquid is supplied from a head tank or a liquid cartridge.

  Further, the flow path plate 2 has a circulating liquid chamber 41 communicating with the nozzle passage 5, a circulating flow path side fluid resistance portion 42 communicating with the circulating liquid chamber 41, on the nozzle plate 1 side opposite to the individual liquid chamber 6. Each groove part which forms the discharge flow path 43 which leads to the circulation flow path side fluid resistance part 42 is formed. Further, the discharge channel 43 communicates with a circulation common liquid chamber 45 formed in the frame member 20 through a passage 44 formed by a through hole. A flow path from the circulating liquid chamber 41 to the circulating common liquid chamber 45 constitutes a circulating flow path.

  The frame member 20 is provided with a supply port 23 that communicates with the common liquid chamber 10 and a circulation port (discharge port) 46 that communicates with the circulation common liquid chamber 45.

  In the liquid discharge head configured as described above, for example, by lowering the voltage applied to the piezoelectric element 12 from the reference potential, the piezoelectric element 12 contracts, and the diaphragm 3 is pulled to expand the volume of the individual liquid chamber 6. The liquid flows into the individual liquid chamber 6.

  Thereafter, the voltage applied to the piezoelectric element 12 is increased to extend the piezoelectric element 12 in the stacking direction, and the diaphragm 3 is deformed in the direction toward the nozzle 4 to contract the volume of the individual liquid chamber 6. The liquid in 6 is pressurized, and the liquid is discharged from the nozzle 4.

  Then, by returning the voltage applied to the piezoelectric element 12 to the reference potential, the diaphragm 3 is restored to the initial position, and the individual liquid chamber 6 expands to generate a negative pressure. The chamber 6 is filled with liquid. Therefore, after the vibration of the meniscus surface of the nozzle 4 is attenuated and stabilized, the operation for the next discharge is started.

  Note that the driving method of the head is not limited to the above example (pulling-pushing), and it is also possible to perform striking or pushing depending on the direction to which the driving waveform is given.

  Next, the flow of the liquid and the arrangement position of the nozzles in the liquid discharge head will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional explanatory view of the main part of FIG.

  In this liquid discharge head, the nozzle passage 5 through which the liquid flows toward the nozzle side through the individual liquid chamber 6 and the nozzle 4, and the direction in which the liquid intersects the direction of flow in the nozzle passage 5 (here, orthogonal directions) ) To the circulating fluid chamber 41.

  Here, the flow direction of the liquid in the nozzle passage 5 indicated by the arrow 61 directed from the individual liquid chamber 6 through the nozzle passage 5 toward the nozzle 4 is defined as the first direction a, and indicated by the arrow 62 along the circulating liquid chamber 41. When the direction of the liquid flow is the second direction b, the first direction a and the second direction b intersect. Here, the nozzle passage 5 and the circulating fluid chamber 41 are arranged so that the first direction a and the second direction b are orthogonal to each other.

  Then, the liquid passage side opening 41a of the circulating fluid chamber 41 communicates with the nozzle passage 5, the liquid inlet side opening 4a of the nozzle 4 faces the boundary portion 60 between the nozzle passage 5 and the circulating fluid chamber 41, and the liquid inflow side opening 4a. A part faces the nozzle passage 5 (faces), and the remaining part faces the circulating fluid chamber 41 (faces).

  Thereby, the liquid inflow side opening 4a of the nozzle 4 faces the region (boundary portion 60) where the liquid flow direction changes from the first direction a to the second direction b. The region where the liquid inflow side opening 4a of the nozzle 4 faces includes a region where all the liquid flows in the second direction b (a region facing the circulating fluid chamber 41).

  With this configuration, the liquid is supplied to the individual liquid chamber 6 by obtaining the supply flow path side fluid resistance portion 7 from the common liquid chamber 10 as shown by the white arrow in FIGS. 3 and 4. It flows from the individual liquid chamber 6 through the nozzle passage 5 toward the nozzle 4 side.

  Then, the flow direction is changed 90 degrees from the nozzle passage 5 to flow into the circulating liquid chamber 41, and further flows into the circulating common liquid chamber 45 through the circulating flow path side fluid resistance portion 42, the discharge flow path 43 and the passage 44.

  In this case, as shown in FIG. 5, when the liquid circulates, the liquid changes from the first direction a into the nozzle 4 when the flow direction changes from the first direction a to the second direction b. Becomes easier to flow.

  At this time, since the opening cross-sectional area of the circulating fluid chamber 41 is smaller than the opening cross-sectional area of the nozzle passage 5, the flow velocity of the liquid is faster in the second direction b than in the first direction a, and the nozzle 4 Since it is arranged immediately before the flow velocity increases, the liquid flowing from the first direction a can easily escape into the nozzle.

  Further, the liquid in the nozzle 4 is easily scraped by the flow of the liquid in the direction c that wraps around from the first direction a to the second direction b.

  In this way, the liquid inside the nozzle 4 is easily stirred.

  Here, a comparative example will be described with reference to FIG. FIG. 8 is an explanatory diagram for explaining the comparative example.

  In this comparative example, the individual liquid chamber 6 and the circulating liquid chamber 41 are arranged in parallel, the first direction a and the second direction b are arranged in opposite directions, and the liquid inflow side opening 4a of the nozzle 4 is provided with the individual liquid. In this arrangement, the chamber 6 and the circulating fluid chamber 41 are opposed to each other.

  In the configuration of this comparative example, the liquid inflow side opening 4 a of the nozzle 4 is located outside the flow c that makes a U-turn from the individual liquid chamber 6 to the circulating liquid chamber 41, so that the liquid touches the inside of the nozzle 4. It just flows. Therefore, the liquid in the nozzle 4 cannot be scraped out and the liquid in the nozzle 4 cannot be stirred.

  Thus, according to the present embodiment, the liquid inside the nozzle 4 can be easily stirred, so that the change in the characteristics of the liquid during drying or the like can be reduced.

  In the present embodiment, the circulation channel includes the circulation channel side fluid resistance portion 42 on the downstream side of the nozzle 4 in the liquid flow direction. And the fluid resistance of the nozzle 4 is made smaller than the fluid resistance of the circulation flow path side fluid resistance part 42.

  Thereby, the energy efficiency for discharging the liquid from the nozzle 4 is improved. Moreover, since the fluid resistance of the nozzle 4 is reduced, the liquid can flow more easily.

  In the present embodiment, the opening cross-sectional area of the circulating liquid chamber 41 is made smaller than the opening cross-sectional area of the nozzle passage 5, which is a flow path for the liquid from the individual liquid chamber 6 toward the nozzle 4.

  As a result, the flow rate is increased and the liquid is easily stirred.

  Next, a liquid ejection head according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic explanatory diagram of a main part of the liquid discharge head.

  In the present embodiment, the liquid inflow side opening 40 a of the circulation flow path 40 communicates with the side wall of the individual liquid chamber 6.

  In this case, when the direction of the liquid flow in the individual liquid chamber 6 is the first direction a and the direction of the liquid flow in the circulation channel 40 is the second direction b, the first direction a and the second direction b are Crossed. Here, the individual liquid chamber 6 and the circulation flow path 40 are arranged so that the first direction a and the second direction b are orthogonal to each other.

  The liquid inflow side opening 4a of the nozzle 4 faces the boundary portion between the individual liquid chamber 6 and the circulation flow path 40, a part of the liquid inflow side opening 4a faces (faces) the individual liquid chamber 6, and the remaining part circulates. Opposite (facing) the flow path 40.

  Accordingly, the liquid inflow side opening 4a of the nozzle 4 faces a region (boundary portion) where the liquid flow direction changes from the first direction a to the second direction b. The region where the liquid inflow side opening 4a of the nozzle 4 faces includes a region where the liquid flow direction is all in the second direction b (a region facing the circulation flow path 40).

  Even in such a configuration, as in the first embodiment, when the liquid circulates, the nozzle changes from the first direction a to the second direction b where the liquid intersects from the first direction a. Since the liquid easily flows into the nozzle 4, the liquid inside the nozzle 4 is easily stirred.

  Next, a liquid ejection head according to a third embodiment of the invention will be described with reference to FIG. FIG. 8 is a schematic explanatory diagram of a main part of the liquid discharge head.

  In the present embodiment, the opening 40 a on the liquid inflow side of the circulation channel 40 communicates with the side wall of the nozzle passage 5.

  In this case, when the direction of the liquid flow in the nozzle passage 5 is the first direction a and the direction of the liquid flow in the circulation passage 40 is the second direction b, the first direction a and the second direction b intersect. doing. Here, the nozzle passage 5 and the circulation passage 40 are arranged so that the first direction a and the second direction b are orthogonal to each other.

  The liquid inflow side opening 4 a of the nozzle 4 is at least partially in a region 48 on the circulation flow path 40 side including a central position 71 in a direction orthogonal to the direction of liquid flow (first direction a) in the nozzle passage 5. It is arranged at the position to face. Here, the liquid inflow side opening 4a of the nozzle 4 is disposed at a position facing the nozzle passage 5 as a whole and closest to the center position 71 side.

  Even with this configuration, when the liquid circulates, the liquid easily flows into the nozzle 4 from the first direction a when the direction of flow of the liquid changes from the first direction a to the second direction b. Therefore, the liquid inside the nozzle 4 is easily stirred.

  Next, a liquid ejection head according to a fourth embodiment of the invention will be described with reference to FIG. FIG. 9 is a schematic explanatory diagram of a main part of the liquid discharge head.

  In the present embodiment, in the configuration of the third embodiment, the nozzle 4 is provided at a position where the liquid inflow side opening 4 a is located at the boundary 60, and the liquid inflow side opening 4 a of the nozzle 4 is partially opposed to the nozzle passage 5. The remaining portion faces the circulation flow path 40.

  Here, the liquid inflow side opening 4 a of the nozzle 4 is arranged at a position where the region facing the circulation flow path 40 is larger than the region facing the nozzle passage 5 in the direction orthogonal to the first direction a. Yes.

  Even in this case, as in the first embodiment, when the liquid circulates, when the direction of flow of the liquid changes from the first direction a to the second direction b intersecting from the first direction a, the first direction a in the nozzle 4 Since the liquid easily flows into the nozzle 4, the liquid inside the nozzle 4 is easily stirred.

  Next, a liquid ejection head according to a fifth embodiment of the invention will be described with reference to FIG. FIG. 10 is a schematic explanatory view of a main part of the liquid discharge head.

  In the present embodiment, the liquid inflow side opening 40 a of the circulation flow path 40 communicates with the side wall of the individual liquid chamber 6.

  In this case, when the direction of the liquid flow in the individual liquid chamber 6 is the first direction a and the direction of the liquid flow in the circulation channel 40 is the second direction b, the first direction a and the second direction b are Crossed. Here, the individual liquid chamber 6 and the circulation flow path 40 are arranged so that the first direction a and the second direction b are orthogonal to each other.

  The liquid inflow side opening 4a of the nozzle 4 is at least partially in a region 48 on the circulation flow path 40 side including a central position 71 in a direction orthogonal to the liquid flow direction (first direction a) in the individual liquid chamber 6. It is arranged at the position where it faces. Here, the liquid inflow side opening 4a of the nozzle 4 is disposed at a position facing the individual liquid chamber 6 as a whole and closest to the center position 71 side.

  Even with this configuration, when the liquid circulates, the liquid easily flows into the nozzle 4 from the first direction a when the direction of flow of the liquid changes from the first direction a to the second direction b. Therefore, the liquid inside the nozzle 4 is easily stirred.

  Next, a liquid ejection head according to a sixth embodiment of the invention will be described with reference to FIG. FIG. 11 is a schematic explanatory diagram of a main part of the liquid discharge head.

  In the present embodiment, in the configuration of the fifth embodiment, the nozzle 4 is provided at a position where the liquid inflow side opening 4a is applied to the boundary 60, and the liquid inflow side opening 4a of the nozzle 4 is partially in the individual liquid chamber 6. Oppositely, the remaining part faces the circulation channel 40.

  Here, the liquid inflow side opening 4a of the nozzle 4 is disposed at a position where the region facing the circulation flow path 40 is larger than the region facing the individual liquid chamber 6 in the direction orthogonal to the first direction a. ing.

  Even in this case, as in the first embodiment, when the liquid circulates, when the direction of flow of the liquid changes from the first direction a to the second direction b intersecting from the first direction a, the first direction a in the nozzle 4 Since the liquid easily flows into the nozzle 4, the liquid inside the nozzle 4 is easily stirred.

  Next, a liquid ejection head according to a seventh embodiment of the invention will be described with reference to FIG. FIG. 12 is a schematic explanatory diagram of a main part of the liquid discharge head.

  In the present embodiment, the opening 42 a on the liquid inflow side of the circulation flow path side fluid resistance portion 42 constituting the circulation flow path is communicated with the side wall of the nozzle passage 5. The opening 42a is also an opening on the liquid inflow side of the circulation channel (the opening 40a in the third embodiment).

  In this case, when the direction of the liquid flow in the nozzle passage 5 is the first direction a and the direction of the liquid flow in the circulation flow path side fluid resistance portion 42 is the second direction b, the first direction a and the second direction b And intersect. Here, the nozzle passage 5 and the circulation flow path side fluid resistance portion 42 are arranged so that the first direction a and the second direction b are orthogonal to each other.

  A part of the liquid inflow side opening 4 a of the nozzle 4 faces the nozzle passage 5, and the remaining part faces the circulation flow path side fluid resistance part 42.

  Here, since the length of the circulation flow path side fluid resistance portion 42 in the second direction b is longer than the diameter of the liquid inflow side opening 4a of the nozzle 4, when the liquid circulates, the liquid intersects from the first direction a. When the flow direction is changed to the two directions b, the flow path cross-sectional area is reduced and the flow velocity is increased.

  Thereby, since it becomes easy for a liquid to flow into the nozzle 4 in which the liquid inflow side opening 4a faces the circulation flow path side fluid resistance part 42, the liquid inside the nozzle 4 becomes easy to be stirred.

  Next, a liquid ejection head according to an eighth embodiment of the invention will be described with reference to FIG. FIG. 13 is a schematic explanatory diagram of a main part of the liquid discharge head.

  In the present embodiment, the liquid inflow side opening 42 a of the circulation channel side fluid resistance portion 42 constituting the circulation channel communicates with the side wall of the individual liquid chamber 6.

  In this case, when the direction of the liquid flow in the individual liquid chamber 6 is the first direction a and the direction of the liquid flow in the circulation flow path side fluid resistance unit 42 is the second direction b, the first direction a and the second direction Crosses b. Here, the individual liquid chamber 6 and the circulation flow path side fluid resistance portion 42 are arranged so that the first direction a and the second direction b are orthogonal to each other.

  A part of the liquid inflow side opening 4 a of the nozzle 4 faces the individual liquid chamber 6, and the remaining part faces the circulation flow path side fluid resistance part 42.

  Here, since the length of the circulation flow path side fluid resistance portion 42 in the second direction b is longer than the diameter of the liquid inflow side opening 4a of the nozzle 4, when the liquid circulates, the liquid intersects from the first direction a. When the flow direction is changed to the two directions b, the flow path cross-sectional area is reduced and the flow velocity is increased.

  Thereby, since it becomes easy for a liquid to flow into the nozzle 4 in which the liquid inflow side opening 4a faces the circulation flow path side fluid resistance part 42, the liquid inside the nozzle 4 becomes easy to be stirred.

  Next, an example of an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. FIG. 14 is an explanatory plan view of the main part of the apparatus, and FIG. 15 is an explanatory side view of the main part of the apparatus.

  This apparatus is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning moving mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 spans the left and right side plates 491A and 491B and holds the carriage 403 so as to be movable. The carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 spanned between the driving pulley 406 and the driven pulley 407.

  A liquid discharge unit 440 in which the liquid discharge head 404 and the head tank 441 according to the present invention are integrated is mounted on the carriage 403. The liquid discharge head 404 of the liquid discharge unit 440 discharges, for example, yellow (Y), cyan (C), magenta (M), and black (K) liquids. The liquid ejection head 404 is mounted with a nozzle row composed of a plurality of nozzles arranged in the sub-scanning direction orthogonal to the main scanning direction, and the ejection direction facing downward.

  The liquid stored in the liquid cartridge 450 is supplied to the head tank 441 by the supply mechanism 494 for supplying the liquid stored outside the liquid discharge head 404 to the liquid discharge head 404.

  The supply mechanism 494 includes a cartridge holder 451 that is a filling unit for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, and the like. The liquid cartridge 450 is detachably attached to the cartridge holder 451. Liquid is fed from the liquid cartridge 450 to the head tank 441 by the liquid feeding unit 452 via the tube 456.

  This apparatus includes a transport mechanism 495 for transporting the paper 410. The transport mechanism 495 includes a transport belt 412 serving as transport means, and a sub-scanning motor 416 for driving the transport belt 412.

  The conveyance belt 412 adsorbs the paper 410 and conveys it at a position facing the liquid ejection head 404. The transport belt 412 is an endless belt and is stretched between the transport roller 413 and the tension roller 414. The adsorption can be performed by electrostatic adsorption or air suction.

  The transport belt 412 rotates in the sub-scanning direction when the transport roller 413 is rotationally driven by the sub-scanning motor 416 via the timing belt 417 and the timing pulley 418.

  Further, on one side of the carriage 403 in the main scanning direction, a maintenance / recovery mechanism 420 that performs maintenance / recovery of the liquid ejection head 404 is disposed on the side of the transport belt 412.

  The maintenance / recovery mechanism 420 includes, for example, a cap member 421 for capping the nozzle surface (surface on which the nozzle is formed) of the liquid ejection head 404, a wiper member 422 for wiping the nozzle surface, and the like.

  The main scanning movement mechanism 493, the supply mechanism 494, the maintenance / recovery mechanism 420, and the transport mechanism 495 are attached to a housing including the side plates 491A and 491B and the back plate 491C.

  In this apparatus configured as described above, the paper 410 is fed and sucked onto the transport belt 412, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412.

  Therefore, the liquid ejection head 404 is driven in accordance with the image signal while moving the carriage 403 in the main scanning direction, thereby ejecting liquid onto the stopped paper 410 to form an image.

  Thus, since this apparatus includes the liquid ejection head according to the present invention, a high-quality image can be stably formed.

  Next, another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 16 is an explanatory plan view of the main part of the unit.

  The liquid discharge unit includes a casing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning moving mechanism 493, a carriage 403, and a liquid among the members constituting the liquid discharge device. The discharge head 404 is configured.

  Note that a liquid discharge unit in which at least one of the above-described maintenance and recovery mechanism 420 and the supply mechanism 494 is further attached to, for example, the side plate 491B of the liquid discharge unit may be configured.

  Next, still another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 17 is an explanatory front view of the unit.

  This liquid discharge unit includes a liquid discharge head 404 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

  The flow path component 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path component 444. In addition, a connector 443 that is electrically connected to the liquid ejection head 404 is provided above the flow path component 444.

  Next, another example of an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. FIG. 18 is a schematic explanatory view of the apparatus, and FIG. 19 is a plan explanatory view of the head unit of the apparatus.

  This apparatus includes a carry-in means 501 for carrying in the continuous medium 510, a guide carrying means 503 for guiding and carrying the continuous medium 510 carried from the carry-in means 501 to the printing means 505, and discharging liquid to the continuous medium 510. A printing unit 505 that performs printing for forming an image, a drying unit 507 that dries the continuous medium 510, and a discharge unit 509 that discharges the continuous medium 510 are provided.

  The continuous medium 510 is fed out from the original winding roller 511 of the carry-in means 501, guided and conveyed by the respective rollers of the carry-in means 501, the guide conveyance means 503, the drying means 507 and the discharge means 509, and the take-up roller 591 of the discharge means 509. It is wound up by.

  The continuous medium 510 is conveyed on the conveyance guide member 559 by the printing unit 505 so as to face the head unit 550 and the head unit 555, and an image is formed by the liquid ejected from the head unit 50. Post-processing is performed with the processing liquid.

  Here, the head unit 50 includes, for example, full-line head arrays 551K, 551C, 551M, and 551Y for four colors from the upstream side in the medium conveyance direction (hereinafter referred to as “head array 551” when colors are not distinguished). ) Is arranged.

  Each head array 551 is a liquid ejecting unit, and ejects black K, cyan C, magenta M, and yellow Y liquids to the transported continuous medium 510, respectively. The type and number of colors are not limited to this.

  For example, as shown in FIG. 19, the head array 551 is configured by arranging a plurality of liquid ejection heads (hereinafter also simply referred to as “heads”) 1000 according to the present invention on a base member 552 in a staggered manner. There is, but is not limited to this.

  Next, an example of the liquid circulation system in this apparatus will be described with reference to FIG. FIG. 20 is a block diagram for explaining the system.

  The liquid circulation system 630 includes a main tank 602, a head 1000, a supply tank 631, a circulation tank 632, a compressor 633, a vacuum pump 634, a first liquid feed pump 635, a second liquid feed pump 636, a supply side pressure sensor 637, and a circulation side. A pressure sensor 638, regulators (R) 639a, 639b, and the like are included.

  The supply-side pressure sensor 637 is connected between the supply tank 631 and the head 1000 and is connected to the supply flow path side connected to the supply port 23 (see FIG. 1) of the head 1000. The circulation side pressure sensor 638 is connected between the head 1000 and the circulation tank 632 and on the circulation channel side connected to the circulation port 46 (see FIG. 1) of the head 1000.

  One of the circulation tanks 632 is connected to the supply tank 631 via the first liquid feed pump 635, and the other of the circulation tanks 632 is connected to the main tank 602 via the second liquid feed pump 636.

  As a result, liquid flows from the supply tank 631 through the supply port 23 into the head 1000, is discharged from the circulation port 46, and is discharged to the circulation tank 632. Further, the liquid is circulated by the liquid being further fed from the circulation tank 632 to the supply tank 631 by the first liquid feed pump 635.

  In addition, a compressor 633 is connected to the supply tank 631, and the supply side pressure sensor 637 is controlled so as to detect a predetermined positive pressure. On the other hand, a vacuum pump 634 is connected to the circulation tank 632 and is controlled so that a predetermined negative pressure is detected by the circulation side pressure sensor 638.

  Thereby, the negative pressure of the meniscus can be kept constant while circulating the liquid through the head 1000.

  Further, when the liquid is discharged from the nozzle 4 of the head 1000, the amount of liquid in the supply tank 631 and the circulation tank 632 decreases. Therefore, the liquid is replenished from the main tank 602 to the circulation tank 632 using the second liquid feeding pump 636 as appropriate. The liquid replenishment timing from the main tank 602 to the circulation tank 632 is the liquid level provided in the circulation tank 632 such that liquid replenishment is performed when the liquid level of the liquid in the circulation tank 632 falls below a predetermined height. It can be controlled by the detection result of a sensor or the like.

  In the present application, the “apparatus for discharging liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as an “apparatus that ejects liquid”, an image forming apparatus that forms an image on a medium by ejecting liquid, a powder is formed in layers to form a three-dimensional structure (three-dimensional structure) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “thing to which liquid can adhere” means that liquid can adhere even temporarily. The material to which “the liquid adheres” may be any material as long as the liquid can temporarily adhere, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics.

  “Liquid” also includes ink, treatment liquid, DNA sample, resist, pattern material, binder, modeling liquid, and the like.

  Further, the “device for ejecting liquid” includes both a serial type device that moves the liquid ejection head and a line type device that does not move the liquid ejection head, unless otherwise specified.

  In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulator for granulating raw material fine particles by spraying a composition liquid dispersed in a solution through a nozzle.

  A “liquid ejection unit” is a unit in which functional parts and mechanisms are integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated as in the liquid discharge unit 440 shown in FIG. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. Further, as shown in FIG. 9, there is a liquid discharge unit in which a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

  Also, as shown in FIG. 10, there is a liquid discharge unit in which a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and the liquid discharge head and the supply mechanism are integrated. .

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  The “liquid discharge head” is not limited to the pressure generating means to be used. For example, in addition to the piezoelectric actuator as described in the above embodiment (a multilayer piezoelectric element may be used), a thermal actuator using an electrothermal conversion element such as a heating resistor, a diaphragm and a counter electrode are included. An electrostatic actuator or the like may be used.

  In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

DESCRIPTION OF SYMBOLS 1 Nozzle plate 2 Flow path plate 3 Vibrating plate 4 Nozzle 5 Nozzle path 6 Individual liquid chamber 7 Supply flow path side fluid resistance part 10 Common liquid chamber 11 Piezoelectric actuator 20 Frame member 40 Circulating flow path 41 Circulating liquid chamber (circulating flow path)
42 Circulating channel side fluid resistance section 45 Circulating common liquid chamber 403 Carriage 404 Liquid ejection head 440 Liquid ejection unit 630 Liquid circulation system 1000 Liquid ejection head

Claims (11)

A nozzle for discharging liquid;
An individual liquid chamber leading to the nozzle;
A circulation flow path leading to the individual liquid chamber,
When the direction of the liquid flow in the individual liquid chamber is a first direction and the direction of the liquid flow in the circulation channel is a second direction,
The first direction and the second direction intersect,
The liquid discharge head according to claim 1, wherein the liquid inflow side opening of the nozzle faces a region where the direction of the liquid flow changes from the first direction to the second direction. 2. The liquid discharge head according to claim 1, wherein the region where the liquid inflow side opening of the nozzle faces includes a region in which the flow direction of the liquid is all in the second direction. The liquid discharge head according to claim 1, wherein a cross-sectional area of the circulation flow path is smaller than a cross-sectional area of the flow path of the liquid from the individual liquid chamber toward the nozzle. The circulation flow path includes a circulation flow path side fluid resistance portion disposed downstream of the nozzle in the second direction,
4. The liquid discharge head according to claim 1, wherein a fluid resistance of the nozzle is smaller than a fluid resistance of the circulation flow path side fluid resistance portion. 5. A nozzle for discharging liquid;
An individual liquid chamber leading to the nozzle;
A nozzle passage through the individual liquid chamber and the nozzle;
A circulation flow path leading to the nozzle passage,
When the direction of the liquid flow in the nozzle passage is a first direction and the direction of the liquid flow in the circulation channel is a second direction,
The first direction and the second direction intersect,
The liquid inflow side opening of the nozzle faces a boundary portion between the nozzle passage and the circulation channel,
A liquid discharge head, wherein a part of the liquid inflow side opening of the nozzle faces the nozzle passage. A nozzle for discharging liquid;
An individual liquid chamber leading to the nozzle;
A circulation flow path leading to the individual liquid chamber,
When the direction of the liquid flow in the individual liquid chamber is a first direction and the direction of the liquid flow in the circulation channel is a second direction,
The first direction and the second direction intersect,
The liquid inflow side opening of the nozzle is arranged in a region on the circulation flow path side that includes a central position in a direction orthogonal to the liquid flow direction in the individual liquid chamber, facing the individual liquid chamber. Liquid discharge head. A nozzle passage through the individual liquid chamber and the nozzle;
A circulation flow path leading to the nozzle passage,
When the direction of the liquid flow in the nozzle passage is a first direction and the direction of the liquid flow in the circulation channel is a second direction,
The first direction and the second direction intersect,
The liquid inflow side opening of the nozzle is disposed in a region on the circulation flow path side including a center position in a direction orthogonal to the liquid flow direction in the nozzle passage, facing the nozzle passage. Liquid discharge head. The liquid discharge head according to claim 1, wherein the first direction and the second direction are perpendicular to each other.   A liquid discharge unit comprising the liquid discharge head according to claim 1. A head tank for storing liquid to be supplied to the liquid discharge head, a carriage on which the liquid discharge head is mounted, a supply mechanism for supplying liquid to the liquid discharge head, a maintenance / recovery mechanism for maintaining and recovering the liquid discharge head, and the liquid 10. The liquid discharge unit according to claim 9, wherein the liquid discharge head is integrated with at least one of a main scanning movement mechanism that moves the discharge head in the main scanning direction.   An apparatus for ejecting liquid, comprising the liquid ejection head according to claim 1 or the liquid ejection unit according to claim 9 or 10.

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