CN107538910B - Ink jet head and ink jet recording apparatus - Google Patents
Ink jet head and ink jet recording apparatus Download PDFInfo
- Publication number
- CN107538910B CN107538910B CN201710492853.5A CN201710492853A CN107538910B CN 107538910 B CN107538910 B CN 107538910B CN 201710492853 A CN201710492853 A CN 201710492853A CN 107538910 B CN107538910 B CN 107538910B
- Authority
- CN
- China
- Prior art keywords
- ink
- common
- flow path
- channel
- ink jet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
- B41J2202/01—Embodiments of or processes related to ink-jet heads
- B41J2202/10—Finger type piezoelectric elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
- B41J2202/01—Embodiments of or processes related to ink-jet heads
- B41J2202/12—Embodiments of or processes related to ink-jet heads with ink circulating through the whole print head
Landscapes
- Particle Formation And Scattering Control In Inkjet Printers (AREA)
- Ink Jet (AREA)
Abstract
An ink jet head which can realize miniaturization and high resolution, maintain the ejection stability of ink, and effectively remove air bubbles, foreign matters and the like in the head together with the ink. An inkjet head (1) according to the present invention is characterized by comprising: the ink jet head includes nozzles N, pressure chambers 311, a piezoelectric element 42 (pressure generating means), an individual communication channel 102 through which ink in the pressure chambers 311 can be discharged, a common channel 703 connected to the individual communication channel 102 and merging the ink discharged from the individual communication channel 102, an ink supply channel 2a communicating with the common channel 703 and capable of supplying the ink to the common channel 703 without passing through the pressure chambers 311, and an ink discharge channel 2b through which the ink in the common channel 703 can be discharged, wherein one end of the common channel 703 in the arrangement direction of the plurality of nozzles N is connected to the ink supply channel 2a, and the other end is connected to the ink discharge channel 2 b.
Description
Technical Field
The present invention relates to an ink jet head and an ink jet recording apparatus.
Background
Conventionally, there is known an ink jet recording apparatus which forms an image on a recording medium by ejecting ink stored in a pressure chamber from a plurality of nozzles provided in an ink jet head.
In such an ink jet recording apparatus, problems such as nozzle clogging and poor ejection may occur due to bubbles generated in the ink jet head, foreign matter mixed in, and the like. Further, depending on the type of ink, if the ink is not used for a long time, the viscosity of the ink near the nozzle may be increased by deposition of ink particles, and it may be difficult to obtain stable ink ejection performance.
Therefore, an ink jet head is known which has a flow path in the head through which ink in a pressure chamber can circulate, and which can discharge bubbles, foreign matter, and the like in the head to the outside of the head together with the ink.
For example, patent documents 1 and 2 disclose an ink jet head including, in a head: a supply port for supplying ink to the pressure chambers in common, a common flow path in which the individual communication flow paths for discharging ink from the pressure chambers are merged, and a discharge flow path for discharging ink from the common flow path to the outside of the head.
Documents of the prior art
Patent document
Patent document 1: japanese patent No. 5563332
Patent document 2: japanese laid-open patent publication No. 2015-100989
Disclosure of Invention
However, when the ink in the head is circulated when the ink is ejected, the ink jet heads described in patent documents 1 and 2 have a water stop portion in the common flow path or have a flow direction other than one direction, and therefore it is not easy to discharge bubbles, foreign matters, and the like discharged from the individual channels to the outside of the head. Further, these bubbles, foreign substances, and the like remain in the flow path and clog the flow path, which hinders the circulation of the ink. In addition, since bubbles remain in the flow path, the state of the pressure wave changes, and the ejection stability of the ink in the nearby channel may be lowered.
In recent years, it has been required to arrange nozzles at high density for downsizing an ink jet head and for increasing the resolution of an image. Therefore, it is desired to obtain a method capable of effectively removing bubbles, foreign substances, and the like in the head while coping with miniaturization and high resolution with a configuration as simple as possible.
The present invention has been made in view of such problems, and an object of the present invention is to provide an ink jet head and an ink jet recording apparatus, which can efficiently remove air bubbles, foreign substances, and the like in a head chip together with ink while maintaining ejection stability of ink with a simple configuration.
In order to solve the above problem, the invention according to a first aspect provides an ink jet head comprising:
a plurality of nozzles that eject ink;
a plurality of pressure chambers which are provided in communication with each of the plurality of nozzles and store the ink discharged from the nozzles;
a plurality of pressure generating units provided corresponding to each of the plurality of pressure chambers, for applying pressure to the ink in the pressure chambers;
a plurality of individual communication channels provided from each of the plurality of pressure chambers or branched from each of communication channels between the pressure chambers and the nozzles, the individual communication channels being capable of discharging ink in the pressure chambers;
a common flow path which connects the plurality of individual communication flow paths and merges the inks discharged from the plurality of individual communication flow paths;
an ink supply path that communicates with the common flow path and is capable of supplying ink to the common flow path without passing through the pressure chamber;
an ink discharge path capable of discharging the ink in the common flow path,
in the common channel, one end portion in the arrangement direction of the plurality of nozzles is connected to the ink supply channel, and the other end portion is connected to the ink discharge channel.
A second aspect of the invention is the ink jet head of the first aspect, wherein a common supply liquid chamber is provided, the common supply liquid chamber storing the ink to be supplied to the pressure chambers, and all ink supply ports for supplying the ink to each of the pressure chambers are connected.
In the ink jet head according to the third aspect, the ink supply path communicates with the common supply liquid chamber.
An ink jet head according to a fourth aspect of the invention is the ink jet head according to the second or third aspect, wherein RT ≦ RS is satisfied when RS is a flow path resistance of the ink supply path and RT is a combined resistance of the individual channels from the ink supply port to the outlets of the individual communication flow paths.
An ink jet head according to a fifth aspect of the invention is the ink jet head according to any one of the second to fourth aspects, wherein RD ≦ RT is satisfied when RD is a flow path resistance of the ink discharge path and RT is a synthetic resistance of the individual channel from the ink supply port to the outlet of the individual communication flow path.
An ink jet head according to a sixth aspect of the invention is the ink jet head according to any one of the first to fifth aspects, wherein a damper is provided facing at least one of the common channels, and is elastically deformed by pressure to be able to change a volume of the channel.
An ink jet head according to a seventh aspect of the invention is the ink jet head according to any one of the first to sixth aspects, wherein the plurality of nozzles are arranged in a plurality of rows, and the common channel is provided for each of the rows.
An eighth aspect of the invention provides an ink jet recording apparatus including the ink jet head of any one of the first to seventh aspects.
An ink jet recording apparatus according to a ninth aspect of the invention is the ink jet recording apparatus according to the eighth aspect, further comprising ink supply means for generating a circulating flow of the ink from the pressure chamber to the individual communication channel.
According to the present invention, with a simple configuration, bubbles, foreign matter, and the like in the head chip can be effectively removed together with the ink while maintaining the ejection stability of the ink.
Drawings
Fig. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus.
Fig. 2A is a perspective view seen from above the inkjet head.
Fig. 2B is a perspective view seen from below the inkjet head.
FIG. 3 is a sectional view of the ink jet head showing a section III-III of FIG. 2A.
Fig. 4 is a sectional view of the ink jet head showing a section IV-IV of fig. 2A.
Fig. 5 is a plan view of the head chip.
Fig. 6 is an enlarged view of a cross section of the head chip.
Fig. 7 is a schematic diagram illustrating the structure of the ink circulation system.
Fig. 8 is an exploded perspective view showing a structure in the vicinity of a head chip according to another embodiment.
Fig. 9 is a sectional view of a head chip of another embodiment.
Description of the symbols
1 ink jet head
102 individually communicate flow paths
2a ink supply path
2b ink discharge path
2c Single channel
3a common feed liquid chamber
311 pressure chamber
42 piezoelectric element (pressure generating unit)
601 ink supply port
71 communication path
703 common flow path
704 damper
8 ink circulation system (ink supply unit)
100 ink jet recording apparatus
N nozzle
Detailed Description
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. However, the scope of the invention is not limited to the illustrated examples. In the following description, members having the same functions and configurations are denoted by the same reference numerals, and description thereof is omitted.
In the following description, an embodiment of a single-pass drawing method using a line head in which heads are linearly arranged and drawing is performed only by conveying a recording medium is described as an example, but the present invention can be applied to an appropriate drawing method, and for example, a drawing method by a scanning method can also be used.
In the following description, the transport direction of the recording medium R is defined as a front-rear direction, a width direction perpendicular to the transport direction on the transport surface of the recording medium R is defined as a left-right direction, and a direction perpendicular to the front-rear direction and the left-right direction is defined as a vertical direction.
[ overview of ink jet recording apparatus ]
The inkjet recording apparatus 100 includes: a platen 1001, a conveying roller 1002, line heads 1003, 1004, 1005, and 1006, and an ink circulation system 8 (see fig. 7) as an ink supply unit (fig. 1).
The platen 1001 supports the recording medium R on the upper surface, and conveys the recording medium R in the conveying direction (front-rear direction) when the conveying roller 1002 is driven.
The line heads 1003, 1004, 1005, 1006 are arranged side by side along a width direction (left-right direction) orthogonal to the conveyance direction from the upstream side to the downstream side in the conveyance direction (front-back direction) of the recording medium R. At least one ink jet head 1, which will be described later, is provided inside the line heads 1003, 1004, 1005, and 1006, and emits cyan (C), magenta (M), yellow (Y), and black (K) inks, for example, onto the recording medium R.
[ schematic Structure of ink-jet head ]
The ink jet head 1 of the present embodiment includes a head chip 2, a common ink chamber 3, a connecting member 4, a holding portion 90, and the like (see fig. 2 to 6 and the like). In fig. 4, in order to explain the positional relationship among the ink supply path 2a, the common flow path 703, and the ink discharge path 2b in the head chip 2, these flow paths are simply shown, and the other flow paths are not shown. In fig. 5, a position corresponding to the cross section of fig. 3 is denoted by III-III.
The head chip 2 is configured by stacking a plurality of substrates in the vertical direction, and a plurality of nozzles N (fig. 2B) for ejecting ink are provided on the lowermost substrate. Further, a pressure chamber 311 for storing ink corresponding to each nozzle N and a piezoelectric element 42 (fig. 3) as a pressure generating means are provided inside the head chip 2. Further, a plurality of ink supply ports 601 are provided in the uppermost layer of the head chip 2 corresponding to the pressure chambers 311, and ink is supplied from the common supply liquid chamber 3a of the common ink chamber 3 to the pressure chambers 311 through the ink supply ports 601. Then, the ink stored in the pressure chamber 311 is pressurized by the displacement of the piezoelectric element 42, and a droplet of the ink is ejected from the nozzle N.
The common ink chamber 3 includes a common supply liquid chamber 3a and a common discharge liquid chamber 3b (fig. 2A and 4), and one of cyan (C), magenta (M), yellow (Y), and black (K), for example, is stored in these liquid chambers.
The common supply liquid chamber 3a is one of the two chambers in the common ink chamber 3, which has a large volume on the left side, and stores ink to be supplied to the head chip 2. An ink supply portion 301 is provided above the common supply liquid chamber 3a, and ink is supplied from the ink supply portion 301 to the interior of the common supply liquid chamber 3a by the ink circulation system 8. Further, dampers 303a are formed at portions of the outer peripheral walls in the front-rear direction and the left-right direction of the common liquid supply chamber 3 a. The damper 303a is formed of, for example, a resin such as elastic polyimide or a metal member such as stainless steel, and prevents the internal pressure of the common ink chamber 3 from rapidly increasing or decreasing.
The common discharge liquid chamber 3b is the one having the smaller volume on the right side of the two chambers of the common ink chamber 3, and stores the ink discharged from the head chip 2. An ink discharge portion 302 is provided above the common discharge chamber 3b, and the ink in the common discharge chamber 3b is discharged from the ink discharge portion 302 to the outside of the ink jet head 1 by the ink circulation system 8. Further, a damper 303b is formed in a part of the outer peripheral wall of the common discharge liquid chamber 3b in the front-rear direction and the left-right direction, similarly to the common supply liquid chamber 3 a.
In the present embodiment, the common ink chamber 3 has a dual chamber structure, but is not limited to this structure. For example, the common ink chamber 3 may be 1 chamber, and a flow may be generated by a pump or the like separately provided in the head to allow the ink discharged from the head chip 2 to flow in.
The connection member 4 is a wiring member connected to a drive unit 5, for example, formed of an FPC (Flexible Printed circuit), and is connected to individual wires 57 on the upper surface of the wiring substrate 50 at the end portions of the head chip 2 in the front-rear direction. Then, electric power is supplied from the driving section 5 to the piezoelectric element 42 through the connection member 4 and the individual wire 57.
The holding portion 90 is joined to the upper surface of the head chip 2, and supports the common ink chamber 3. Since the common ink chamber 3 can be provided by using the holding portion 90 as a mark after the holding portion 90 is aligned with the upper surface of the head chip 2, the common ink chamber 3 can be formed on the upper surface of the head chip 2 with high accuracy. In addition, from the viewpoint of performing alignment with high accuracy, it is preferable that alignment marks (not shown) be provided on the head chip 2 and the holding portion 90, respectively, and the alignment marks be bonded to each other.
[ head chip ]
Next, the head chip 2 will be described in detail. Fig. 5 is a plan view of the head chip 2, and the positions of the pressure chamber 311, the communication path 71, and the common flow path 703 formed inside the head chip 2 are shown by broken lines. Fig. 6 is a cross-sectional view of the head chip 2.
The head chip 2 is configured by stacking and integrating the nozzle substrate 10, the common channel substrate 70, the intermediate substrate 20, the pressure chamber substrate 30, the partition substrate 40, the wiring substrate 50, and the adhesive layer 60 in this order from the lower side (see fig. 6).
The nozzle substrate 10 is provided with: the ink jet head includes a nozzle N, a large diameter portion 101 communicating with the nozzle N and having a larger diameter than the nozzle N, and a separate communication channel 102 branching from the large diameter portion 101 and used for ink circulation. The nozzles N are arranged in a plurality of rows (for example, 4 rows) in the left-right direction, for example (see fig. 2B).
The nozzle substrate 10 is manufactured from an SOI substrate and is formed by anisotropic etching with high precision. Therefore, the length of the nozzle N in the vertical direction and the thickness of the lower portion of the individual communication channel 102 can be reduced to, for example, about 10 μm. Further, since the individual communication flow path 102 branches from the large diameter portion 101 above the nozzle N, air bubbles or foreign matter near the nozzle N can be caused to flow to the individual communication flow path 102 together with the ink.
The common channel substrate 70 is a silicon substrate, and a large diameter portion 701, a throttle portion 702, and a common channel 703 are formed on the common channel substrate 70.
The large diameter portion 701 vertically penetrates the common channel substrate 70 and communicates with the large diameter portion 101 of the nozzle substrate 10.
The common flow path 703 is provided along the arrangement direction (left-right direction) of the nozzles N (see fig. 5). The common channel 703 is connected to a row of individual communication channels 102 arranged along the arrangement direction (left-right direction) of the nozzles N, and the inks flowing out from these individual communication channels 102 are merged.
Further, a throttle portion 702 is provided at a connecting portion between the individual communication flow path 102 and the common flow path 703, and the throttle portion 702 is used to appropriately adjust the flow path resistance of the individual communication flow path 102 and improve the injection characteristic. In the common channel 703, one end (left end) in the direction in which the nozzles N are arranged (left-right direction) is connected to the ink supply channel 2a, and the other end (right end) is connected to the ink discharge channel 2b (see fig. 4).
Further, as in the present embodiment, a configuration in which a single row of the individual communication passages 102 arranged along the arrangement direction (left-right direction) of the nozzles N is connected to the common passage 703 is preferable, but of course, this embodiment is not limited thereto.
The upper portion of the ink supply path 2a is connected to the common liquid supply chamber 3a, and the lower portion is connected to the common flow path 703, so that the ink stored in the common liquid supply chamber 3a can be caused to flow directly to the common flow path 703 without passing through the pressure chamber 311.
The upper part of the ink discharge path 2b is connected to the common discharge chamber 3b, and the lower part thereof is connected to the common flow path 703, so that the ink in the common flow path 703 can be discharged to the common discharge chamber 3 b.
Further, a damper 704 is formed on the common flow path substrate 70 on the upper surface facing the common flow path 703. The damper 704 is made of, for example, a Si substrate having a thickness of 1 to 50 μm, and an air chamber 203 is formed on the upper surface of the damper 704. Since the damper 704 is a thin Si substrate, it is elastically deformed by a pressure difference between the common flow path 703 and the air chamber 203, and the volume of the common flow path 703 can be changed. For example, when the pressure in the common flow path 703 abruptly drops, the damper 704 is elastically deformed in the downward direction, and thereby abrupt pressure fluctuation in the ink flow path can be prevented. Further, by making the air chamber 203 a closed space, a damping force when the damper 704 vibrates due to deformation acts, and pressure fluctuation can be further suppressed.
The intermediate substrate 20 is a glass substrate, and the intermediate substrate 20 is formed with a communication hole 201 penetrating in the vertical direction and an air chamber 203 at a position corresponding to an upper surface portion of the damper 704.
The communication hole 201 communicates with the large diameter portion 701. In the present specification, the flow path between the pressure chamber 311 and the nozzle N is referred to as a communication path 71, and in the example shown in fig. 6, the communication path 71 is a flow path including the communication hole 201, the large diameter portion 701, and the large diameter portion 101.
The pressure chamber substrate 30 is composed of a pressure chamber layer 31 and a vibration plate 32.
The pressure chamber layer 31 is a silicon substrate, and the pressure chamber layer 31 is formed with a pressure chamber 311 for storing ink discharged from the nozzle N. The pressure chambers 311 are, for example, substantially circular in plan view, and are arranged in a plurality of rows (for example, 4 rows) corresponding to the nozzle rows in the left-right direction (see fig. 5). The pressure chamber 311 is connected to a communication path 71 serving as a flow path for ejecting ink at a lower front portion. In the pressure chamber layer 31, a communication hole 312 communicating with the pressure chamber 311 is formed so as to penetrate the pressure chamber layer 31 in the vertical direction and extend in the front-rear direction.
The diaphragm 32 is stacked on the upper surface of the pressure chamber layer 31 to cover the opening of the pressure chamber 311, and constitutes an upper wall portion of the pressure chamber 311. An oxide film is formed on the surface of the vibrating plate 32. Further, the diaphragm 32 is formed with a through hole 321 that communicates with the communication hole 312 and penetrates in the upward direction.
The spacer substrate 40 is a substrate made of 42 alloy, and is a spacer layer forming a space 41 for accommodating the piezoelectric element 42 and the like between the diaphragm 32 and the wiring substrate 50.
The piezoelectric element 42 is formed in substantially the same shape as the pressure chamber 311 in a plan view, and is provided at a position facing the pressure chamber 311 with the vibration plate 32 interposed therebetween. The piezoelectric element 42 is an actuator made of pzt (lead zirconium titanate) for deforming the vibration plate 32. Two electrodes 421 and 422 are provided on the upper surface and the lower surface of the piezoelectric element 42, and the electrode 422 on the lower surface side is connected to the vibrating plate 32.
In the spacer substrate 40, a through hole 401 that communicates with the through hole 321 of the vibrating plate 32 and penetrates in the upward direction is formed independently of the space 41.
The wiring board 50 includes an interposer 51 as a silicon substrate. The interposer 51 has two insulating layers 52 and 53 of silicon oxide coated on the lower surface thereof, and an insulating layer 54 of the same silicon oxide coated on the upper surface thereof. The insulating layer 53 positioned below the insulating layers 52 and 53 is stacked on the upper surface of the spacer substrate 40.
The interposer 51 has a through hole 511 penetrating upward, and a through electrode 55 is inserted through the through hole 511. One end of a wire 56 extending in the horizontal direction is connected to the lower end of the through electrode 55, and a stud bump 423 provided on the electrode 421 on the upper surface of the piezoelectric element 42 is connected to the other end of the wire 56 via solder 561 exposed in the space 41. The individual wire 57 is connected to the upper end of the through electrode 55, and the individual wire 57 extends in the horizontal direction and is connected to the connection member 4 (see fig. 3).
The interposer 51 has an inlet 512 that communicates with the through-hole 401 of the spacer substrate 40 and penetrates upward. In the insulating layers 52 to 54, portions covering the vicinity of the inlet 512 are formed to have a larger opening diameter than the inlet 512.
The adhesive layer 60 is a layer that is adhered to the holding portion 90, is a photosensitive resin layer, is a protective layer that protects the individual wires 57, covers the individual wires 57 disposed on the upper surface of the wiring board 50, and is laminated on the upper surface of the insulating layer 54 of the interposer 51. The adhesive layer 60 is provided with an ink supply port 601 which communicates with the inlet 512 and penetrates upward.
Next, the ink flow inside the inkjet head 1 will be described.
The ink stored in the common supply liquid chamber 3a is supplied to the inside of the head chip 2 through the ink supply ports 601 provided corresponding to the respective nozzles N. Then, the ink flows through the inlet 512, the through hole 401, the communication hole 312, and the pressure chamber 311 in this order. Then, the ink flows through the communication path 71 (the communication hole 201, the large diameter portion 701, and the large diameter portion 101) which serves as an ink flow path at the time of ink ejection. Then, the ink flows through the individual communication flow paths 102 branched from the communication path 71, and the inks from the plurality of individual communication flow paths 102 are merged in the common flow path 703.
In the present specification, the ink supply port 601 and the individual communication channels 102 are referred to as individual channels 2 c.
In addition to the flow path passing through the individual channel 2c, the ink stored in the common supply liquid chamber 3a flows through the common flow path 703 from the ink supply port 602 (see fig. 5) through the ink supply path 2 a. In this flow path, the ink stored in the common supply liquid chamber 3a flows directly to the common flow path 703 without passing through the pressure chamber 311 and the like.
As a result, a unidirectional flow without a water stop region is generated in the common channel 703, and the ink merged in the common channel 703 flows to the end of the right head chip 2 and is discharged to the common discharge chamber 3b from the ink discharge port 603 on the upper part of the head chip 2 through the ink discharge channel 2b (see fig. 4 and the like).
[ design of flow channel in head chip ]
The ink supply path 2a, the ink discharge path 2b, and the individual channels 2c in the head chip 2 are preferably designed so that the respective flow path resistances satisfy a predetermined relationship. Specifically, when the flow path resistance of the ink supply path 2a is RS, the flow path resistance of the ink discharge path 2b is RD, and the combined resistance of the individual channels 2c is RT, the shape, length, and the like of the flow path are preferably configured so as to satisfy RD ≦ RT ≦ RS.
If the combined resistance RT of the individual paths 2c and the flow path resistance RS of the ink supply path 2a satisfy the relationship "RT ≦ RS", the ink flows more easily from the common supply liquid chamber 3a to the individual paths 2c than the ink supply path 2 a. Since bubbles and foreign matter in the individual channels 2c cannot be removed if the amount of ink flowing through the individual channels 2c is small, it is preferable to ensure the amount of ink flowing through the individual channels 2c by flowing at least the same amount of ink as the amount of ink supplied to the ink supply path 2a through the individual channels 2c while satisfying "RT ≦ RS".
Further, if the flow path resistance RD of the ink discharge path 2b and the combined resistance RT of the individual channels 2c satisfy the relationship "RD ≦ RT", the ink easily flows from the common flow path 703 to the outside of the head chip 2 through the ink discharge path 2 b. That is, it is preferable to design so as to satisfy "RD ≦ RT" from the viewpoint of easily removing bubbles, foreign matter, and the like flowing to the common flow path 703 together with the ink to the outside of the head chip 2.
Here, a method of calculating the flow path resistance R in each flow path will be described.
When the channel shape is a rectangular parallelepiped, the channel resistance R is 8 η l (h + w) when the width (front-rear direction) of the channel is w (m), the height (vertical direction) of the channel is h (m), the length (left-right direction) of the channel is l (m), and the fluid viscosity of the ink is η (Pa · s)2/(hw)3。
When the flow path is cylindrical, the flow path resistance R is 128 η l/pi d where d (m) is the diameter of the flow path, l (m) is the height (vertical direction) of the flow path, and η (Pa · s) is the fluid viscosity of the ink, and4。
in the case of other shapes, for example, in the case of a taper, the calculation can be performed by dividing into rectangular solids in the longitudinal direction of the taper and integrating.
Next, the synthetic resistance RT of the individual channel 2c is explained.
First, the flow path resistance R of each individual channel 2c can be calculated from the sum of the flow path resistances of the respective flow paths (the inlet 512, the through hole 401, the communication hole 312, the pressure chamber 311, the communication path 71, the individual communication flow path 102, and the throttle section 702) from the ink supply port 601 to the outlet of the individual communication flow path 102.
Here, since the plurality of individual channels 2c are connected in parallel to the common channel 703, the combined resistance RT of the individual channels can be obtained from the sum of the reciprocals of the channel resistances of the individual channels 2 c.
Specifically, for example, when n (n is an integer of 2 or more) individual channels are connected in parallel to the common channel 703, if the channel resistances of the n individual channels are Ri (1), Ri (2), …, and Ri (n), the combined resistance RT of each individual channel can be calculated by the following equation.
1/RT＝(1/Ri(1))+(1/Ri(2))+···+(1/Ri(n))
[ ink circulation System ]
The ink circulation system 8 as the ink supply means is constituted by a supply sub tank 81, a circulation sub tank 82, a main tank 83, and the like (fig. 7).
The supply sub tank 81 is filled with ink to be supplied to the common supply liquid chamber 3a of the common ink chamber 3, and is connected to the ink supply portion 301 through the ink flow path 84.
The circulation subtank 82 is filled with ink discharged from the common discharge chamber 3b of the common ink chamber 3, and is connected to the ink discharge portion 302 through the ink flow path 85.
The supply sub-tank 81 and the circulation sub-tank 82 are provided at different positions in the vertical direction (gravity direction) with respect to the nozzle surface (hereinafter also referred to as "position reference surface") of the head chip 2. Thereby, a pressure P1 due to a water head difference between the position reference surface and the supply sub-tank 81 and a pressure P2 due to a water head difference between the position reference surface and the circulation sub-tank 82 are generated.
The supply sub-tank 81 and the circulation sub-tank 82 are connected by an ink flow path 86. The pressure applied by the pump 88 allows the ink to return from the circulation subtank 82 to the supply subtank 81.
The main tank 83 is filled with ink to be supplied to the sub-tank 81 for supply, and is connected to the sub-tank 81 for supply through an ink flow path 87. The pressure applied by the pump 89 can supply the ink from the main tank 83 to the supply sub tank 81.
Further, the pressure P1 and the pressure P2 can be adjusted by appropriately changing the amount of ink filled in each subtank and the position of each subtank in the vertical direction (the direction of gravity). Further, the ink in the upper portion of the nozzle N can be circulated at an appropriate circulation flow rate by the pressure difference between the pressure P1 and the pressure P2. This can remove air bubbles generated in the head chip 2 and suppress clogging of the nozzle N, injection failure, and the like.
Further, as an example of the ink circulation system 8, a method of controlling the ink circulation by the difference in water level has been described, but it is needless to say that the configuration may be appropriately changed as long as the ink circulation flow can be generated. For example, a pump may be provided between the supply subtank 81 and the ink supply portion 301, and a circulating flow of the ink may be generated by a pressure applied by the pump.
[ ink jet head of another embodiment ]
In the following description, an inkjet head 1 according to another embodiment is described.
The head chip 2 in the ink jet head 1 of the present embodiment is manufactured by stacking a plurality of layers in an aligned manner by using an MEMS (Micro electro mechanical Systems) technique, but the technique of the present invention can be applied to other types of head chips 2. An ink jet head 1 according to another embodiment including a shear mode type head chip 2 will be described below as an example thereof.
In the following description, only the main parts of the ink jet head 1 according to the other embodiment will be described, and the same components as those of the present embodiment will be denoted by the same reference numerals and their description will be omitted.
Fig. 8 is an exploded perspective view showing a structure of the vicinity of the head chip 2 with respect to the ink jet head 1 of another embodiment. In fig. 8, the positions of the ink supply path 2a and the ink discharge path 2b are shown by broken lines. Fig. 9 is a cross-sectional view of the head chip taken along the front-rear direction.
The head chip 2 includes a nozzle substrate 10, a pressure chamber substrate 30, a wiring substrate 50, and the like.
As in the present embodiment, the pressure chamber substrate 30 is provided with a common channel 703, an ink supply channel 2a, and an ink discharge channel 2 b.
The pressure chambers 311 are formed by being partitioned by partition walls formed of a piezoelectric material, and a drive electrode 311a for driving the partition wall between the adjacent pressure chambers 311 is provided on the inner surface of each pressure chamber 311. When a voltage is applied from the wiring 4a of the connection member 4 to the driving electrode 311a via the electrode portion 50a of the wiring board 50, the partition wall portion between the adjacent pressure chambers 311 repeats shear mode type displacement, and pressure is applied to the ink in the pressure chambers 311, whereby the ink is ejected from the nozzle N.
Further, the nozzle substrate 10 is provided with the nozzles N and the individual communication channels 102. The individual communication channel 102 is a channel that communicates the pressure chamber 311 and the common channel 703, and allows ink in the pressure chamber 311 to flow to the common channel 703 (fig. 9).
In the common channel 703, one end (left end) of the common channel 703 is connected to the ink supply channel 2a, and the other end (right end) is connected to the ink discharge channel 2b (see fig. 8). The ink supply path 2a can directly supply ink to the common flow path 703 from a supply liquid chamber (not shown) provided above the head chip 2 without passing through the pressure chamber 311, as in the ink jet head 1 of the present embodiment.
[ technical effects in the invention ]
As described above, the ink jet head 1 of the present invention includes: an individual communication channel 102 which is branched from the pressure chamber 311 or the communication channel 71 between the pressure chamber 311 and the nozzle N and which can discharge the ink in the pressure chamber 311; a common flow path 703 to which the individual communication flow paths 102 are connected and which merges the inks discharged from the individual communication flow paths 102; an ink supply path 2a which communicates with the common flow path 703 and can supply ink to the common flow path 703 without passing through the pressure chamber 311; the ink discharge path 2b is capable of discharging ink in the common channel 703.
In the inkjet head 1 according to the present invention, one end portion of the common channel 703 in the direction in which the nozzles N are arranged is connected to the ink supply channel 2a, and the other end portion is connected to the ink discharge channel 2 b. Thereby, in the common channel 703, the ink flows in one direction from the ink supply channel 2a side toward the ink discharge channel 2b side. That is, a unidirectional flow without a water stop region can be generated. Therefore, bubbles, foreign matter, and the like can be effectively discharged while maintaining the ejection stability of the ink. Further, the structure of the present invention can obtain the above-described effects with a simple structure, and therefore, the present invention is also applicable to a small head in which nozzles are formed at high density.
Further, the inkjet head 1 of the present invention preferably includes the common supply liquid chamber 3a that stores the ink to be supplied to the pressure chambers 311, and all the ink supply ports 601 for supplying the ink to each of the pressure chambers 311 are connected. This makes it possible to achieve the effects of the present invention with a simpler configuration and to miniaturize the ink jet head 1.
In addition, in the ink-jet head 1 of the present invention, it is preferable that the ink supply path 2a communicates with the common liquid supply chamber 3 a. This makes it possible to achieve the effects of the present invention with a simpler configuration and to miniaturize the ink jet head 1.
In the ink jet head 1 of the present invention, it is preferable that RT ≦ RS be satisfied when the channel resistance of the ink supply channel 2a is RS and the combined resistance of the individual channels 2c from the ink supply port 601 to the outlets of the individual communication channels 102 is RT. This ensures the amount of ink flowing into the individual passage 2c, and effectively removes air bubbles, foreign substances, and the like in the individual passage 2 c.
In the ink jet head 1 of the present invention, it is preferable that RD ≦ RT be satisfied when RD is a flow path resistance of the ink discharge path 2b and RT is a combined resistance of the individual channels 2c from the ink supply port 601 to the outlets of the individual communication flow paths 102. Accordingly, the ink easily flows from the common channel 703 to the outside of the head chip 2 through the ink discharge channel 2b, and therefore, bubbles, foreign substances, and the like flowing to the common channel 703 can be easily discharged to the outside of the head chip 2 together with the ink.
Further, the ink jet head 1 of the present invention preferably includes a damper 704, and the damper 704 is provided to face at least one of the common channels 703, and is elastically deformed by pressure to be able to change the volume of the channel. Accordingly, even if the volume of the common channel 703 is reduced, rapid pressure fluctuations in the channel can be easily prevented, and therefore the ink jet head 1 can be further downsized.
In the ink jet head 1 of the present invention, it is preferable that the plurality of nozzles N are arranged in a plurality of rows, and the common channel 703 is provided in each row. This allows the ink to flow in the direction of the array of the nozzles N and in each row, and therefore, bubbles, foreign matter, and the like can be more effectively discharged together with the ink.
The ink jet head 1 of the present invention is applied to an ink jet recording apparatus 100 including the ink jet head 1 and an ink circulation system 8.
[ others ]
The embodiments of the invention disclosed here are examples in all respects and should not be considered as limiting examples. The scope of the present invention is not limited to the above detailed description, but is shown by the scope of the claims of the present application, and includes all modifications within the scope and technical solutions equivalent to the claims.
For example, in the inkjet head 1 of the present embodiment, the ink is supplied from the common supply liquid chamber 3a to the ink supply path 2a, but an ink supply unit capable of directly supplying the ink to the ink supply path 2a may be separately provided. In this case, for example, a second liquid supply chamber may be provided in addition to the common liquid supply chamber 3a, and the ink supply path 2a may be communicated with the second liquid supply chamber.
The channel structure may be changed as appropriate as long as the ink supply channel 2a can directly supply ink to the common channel 703 without passing through the pressure chamber 311. For example, the ink entering the individual channel 2c may branch before the pressure chamber 311 and be connected to the common channel 703.
Further, the common flow path 703 is connected to the single communication flow paths 102 arranged in one row along the arrangement direction (left-right direction) of the nozzles N, but two or more rows of the single communication flow paths 102 may be appropriately changed to communicate with each other. The common flow path 703 is provided along the array (left-right direction) of the nozzles N, but may be branched and merged in the middle. However, from the viewpoint of efficiently discharging bubbles, foreign substances, and the like, it is preferable that such branching is not performed, and the nozzles are arranged in a row-by-row manner along the arrangement (left-right direction) of the nozzles N as shown in fig. 5.
In the present embodiment, the ink inside the head chip 2 is circulated by the ink circulation system 8, but the ink in the ink discharge path 2b may not be circulated but may be discharged, or circulation or discharge may be selected.
Further, if the damper 704 provided in the head chip or the dampers 303a and 303b provided in the common ink chamber can be elastically deformed, the material and size used can be changed as appropriate.
The damper 704 in the head chip is provided so as to face the upper surface of the common flow path 703, but the surface provided may be appropriately changed as long as it is provided so as to face the common flow path 703.
The ink jet head 1 is configured to discharge liquid droplets such as ink by the piezoelectric element, but may be provided with a mechanism capable of discharging liquid droplets, and for example, a thermosensitive device (electrothermal conversion element) may be used.
Claims (8)
1. An ink jet head, comprising:
a plurality of nozzles that eject ink;
a plurality of pressure chambers which are provided in communication with each of the plurality of nozzles and store the ink discharged from the nozzles;
a plurality of pressure generating units provided corresponding to each of the plurality of pressure chambers, for applying pressure to the ink in the pressure chambers;
a plurality of individual communication channels provided from each of the plurality of pressure chambers or branched from each of communication channels between the pressure chambers and the nozzles, the individual communication channels being capable of discharging ink in the pressure chambers;
a common flow path which connects the plurality of individual communication flow paths and merges the inks discharged from the plurality of individual communication flow paths;
an ink supply path that communicates with the common flow path and is capable of supplying ink to the common flow path without passing through the pressure chamber;
an ink discharge path capable of discharging the ink in the common flow path;
a common supply liquid chamber that stores the ink supplied to the pressure chambers and to which all ink supply ports for supplying the ink to each of the pressure chambers are connected;
one end of the common channel in the direction of arrangement of the plurality of nozzles is connected to the ink supply channel, and the other end is connected to the ink discharge channel,
the ink supply path is configured to branch from a portion of a flow path from the ink supply port to the pressure chamber on an upstream side of the pressure chamber.
2. An ink jet head according to claim 1,
the ink supply path communicates with the common supply liquid chamber.
3. An ink jet head according to claim 1 or 2,
when the flow path resistance of the ink supply path is set to RS and the combined resistance of the individual channels from the ink supply port to the outlets of the individual communication flow paths is set to RT, RT ≦ RS is satisfied.
4. An ink jet head according to claim 1 or 2,
when RD is a flow path resistance of the ink discharge path and RT is a combined resistance of the individual channels from the ink supply port to the outlets of the individual communication flow paths, RD ≦ RT is satisfied.
5. An ink jet head according to claim 1 or 2,
the damper is provided so as to face at least one of the common flow paths and is elastically deformed by pressure to change the volume of the flow path.
6. An ink jet head according to claim 1 or 2,
the plurality of nozzles are arranged in a plurality of columns,
the common flow path is provided in each of the columns.
7. An ink-jet recording apparatus is characterized in that,
an ink jet head according to any one of claims 1 to 6.
8. The ink jet recording apparatus according to claim 7,
the ink supply unit is provided for generating a circulating flow of the ink from the pressure chamber to the individual communication channel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016-126140 | 2016-06-27 | ||
| JP2016126140A JP6772582B2 (en) | 2016-06-27 | 2016-06-27 | Inkjet head and inkjet recorder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107538910A CN107538910A (en) | 2018-01-05 |
| CN107538910B true CN107538910B (en) | 2020-10-20 |
Family
ID=60945584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710492853.5A Active CN107538910B (en) | 2016-06-27 | 2017-06-26 | Ink jet head and ink jet recording apparatus |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP6772582B2 (en) |
| CN (1) | CN107538910B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7167697B2 (en) * | 2018-12-21 | 2022-11-09 | セイコーエプソン株式会社 | Liquid ejecting head and liquid ejecting apparatus |
| JP7374681B2 (en) * | 2019-09-12 | 2023-11-07 | 東芝テック株式会社 | Liquid ejection head and liquid ejection device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009143168A (en) * | 2007-12-17 | 2009-07-02 | Fuji Xerox Co Ltd | Liquid droplet discharging unit, liquid droplet discharging head, and image forming apparatus equipped with it |
| JP2015036238A (en) * | 2013-08-15 | 2015-02-23 | 富士フイルム株式会社 | Liquid discharge head and ink jet recorder |
| JP2015058639A (en) * | 2013-09-19 | 2015-03-30 | エスアイアイ・プリンテック株式会社 | Liquid jet head and liquid jet device |
Family Cites Families (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6296020B1 (en) * | 1998-10-13 | 2001-10-02 | Biomicro Systems, Inc. | Fluid circuit components based upon passive fluid dynamics |
| JP3897120B2 (en) * | 2004-06-17 | 2007-03-22 | ソニー株式会社 | Liquid ejecting apparatus and method of manufacturing liquid ejecting apparatus |
| JP5076299B2 (en) * | 2004-09-24 | 2012-11-21 | ブラザー工業株式会社 | Liquid ejector |
| JP2007076015A (en) * | 2005-09-12 | 2007-03-29 | Sony Corp | Liquid ejection head |
| JP2007296675A (en) * | 2006-04-28 | 2007-11-15 | Mimaki Engineering Co Ltd | Fluid ejection device |
| JP4851310B2 (en) * | 2006-12-06 | 2012-01-11 | 富士フイルム株式会社 | Droplet ejection mechanism and image forming apparatus |
| JP4755119B2 (en) * | 2007-02-14 | 2011-08-24 | 株式会社リコー | Liquid supply member for liquid discharge head, liquid discharge apparatus, and image forming apparatus |
| JP2010076415A (en) * | 2007-12-21 | 2010-04-08 | Seiko Epson Corp | Liquid supply device and liquid jetting apparatus |
| JP5206956B2 (en) * | 2008-02-06 | 2013-06-12 | セイコーエプソン株式会社 | Liquid ejecting head and liquid ejecting apparatus |
| CN102026813B (en) * | 2008-05-23 | 2015-05-27 | 富士胶片株式会社 | Fluid droplet ejecting device |
| JP5375064B2 (en) * | 2008-12-11 | 2013-12-25 | セイコーエプソン株式会社 | Liquid discharge head and liquid discharge apparatus |
| JP2010214847A (en) * | 2009-03-18 | 2010-09-30 | Fujifilm Corp | Liquid droplet ejection head and image forming apparatus |
| JP5620726B2 (en) * | 2010-06-30 | 2014-11-05 | 富士フイルム株式会社 | Liquid discharge head and ink jet recording apparatus |
| JP5381915B2 (en) * | 2010-07-01 | 2014-01-08 | コニカミノルタ株式会社 | Ink jet recording head and ink jet recording apparatus |
| JP5881000B2 (en) * | 2011-09-15 | 2016-03-09 | 株式会社リコー | Droplet discharge head and droplet discharge apparatus |
| WO2013108240A1 (en) * | 2012-01-18 | 2013-07-25 | Hewlett-Packard Industrial Printing Ltd. | Fin members to guide fluid |
| US9162453B2 (en) * | 2012-07-30 | 2015-10-20 | Hewlett-Packard Development Company, L.P. | Printhead including integrated circuit die cooling |
| JP6262556B2 (en) * | 2014-02-07 | 2018-01-17 | 京セラ株式会社 | Liquid discharge head and recording apparatus |
| JP2015150882A (en) * | 2014-02-19 | 2015-08-24 | 京セラ株式会社 | Flow channel member, liquid discharge head using the same, and recording device |
| CN104859301B (en) * | 2014-02-26 | 2017-09-05 | 株式会社东芝 | Ink-jet recording ink and recording method |
| JP6410528B2 (en) * | 2014-08-29 | 2018-10-24 | キヤノン株式会社 | Liquid discharge head and head unit using the same |
| JP6700841B2 (en) * | 2016-02-19 | 2020-05-27 | キヤノン株式会社 | Liquid ejection head and liquid ejection device |
| JP2017159561A (en) * | 2016-03-10 | 2017-09-14 | 株式会社リコー | Liquid discharge head, liquid discharge unit, and liquid discharging device |
-
2016
- 2016-06-27 JP JP2016126140A patent/JP6772582B2/en active Active
-
2017
- 2017-06-26 CN CN201710492853.5A patent/CN107538910B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009143168A (en) * | 2007-12-17 | 2009-07-02 | Fuji Xerox Co Ltd | Liquid droplet discharging unit, liquid droplet discharging head, and image forming apparatus equipped with it |
| JP2015036238A (en) * | 2013-08-15 | 2015-02-23 | 富士フイルム株式会社 | Liquid discharge head and ink jet recorder |
| JP2015058639A (en) * | 2013-09-19 | 2015-03-30 | エスアイアイ・プリンテック株式会社 | Liquid jet head and liquid jet device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6772582B2 (en) | 2020-10-21 |
| CN107538910A (en) | 2018-01-05 |
| JP2018001412A (en) | 2018-01-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108025552B (en) | Ink jet head and ink jet recording apparatus | |
| JP6724923B2 (en) | Inkjet head and inkjet recording device | |
| JP6428791B2 (en) | Liquid discharge head, liquid discharge unit, and apparatus for discharging liquid | |
| CN109661311B (en) | Ink jet head and ink jet recording apparatus | |
| US9044957B2 (en) | Liquid ejecting apparatus | |
| CN109414933B (en) | Ink jet recording apparatus | |
| JP2020097171A (en) | Liquid discharge head | |
| JP2017056664A (en) | Ink jet head, ink jet recording device and method for manufacturing ink jet head | |
| WO2018132238A1 (en) | Actuators for fluid delivery systems | |
| CN109421372B (en) | Liquid discharge head, method of controlling the same, liquid discharge head substrate, and apparatus | |
| EP4197792A1 (en) | Head chip, liquid jet head, and liquid jet recording device | |
| JP2022107048A (en) | Droplet injector | |
| US11186085B2 (en) | Head | |
| CN107538910B (en) | Ink jet head and ink jet recording apparatus | |
| CN112297624B (en) | Liquid ejecting head and liquid ejecting apparatus | |
| JP7151708B2 (en) | Liquid ejection head and liquid ejection device | |
| JP7014065B2 (en) | Liquid discharge head and liquid discharge device | |
| JP5167669B2 (en) | Liquid supply device and liquid discharge device | |
| CN105415886A (en) | Flow Path Member, Liquid Ejecting Head, Liquid Ejecting Apparatus And Liquid Stirring Method | |
| JP6915670B2 (en) | Inkjet head, inkjet recording device and manufacturing method of inkjet head | |
| EP4155081A1 (en) | Liquid ejection head | |
| JP7247640B2 (en) | liquid ejection head | |
| CN116160771A (en) | Liquid ejection head | |
| WO2019239576A1 (en) | Inkjet head and inkjet recording device | |
| JP2023128607A (en) | Droplet discharge head and droplet discharge device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |