JP2016087822A - Ink jet device and ink jet method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet device capable of preventing a nozzle from being unable to jet liquid, when applying the liquid containing bioparticles such as cells, over an object to be printed.SOLUTION: There is provided an ink jet device 1 including: a common ink chamber 4 for supplying ink; a first diaphragm 9b for transferring pressure to the common ink chamber; multiple first piezoelectric elements 10 for applying pressure to the first diaphragm; multiple pressure chambers 6 connected to the common ink chamber, and each having a nozzle 5 for jetting ink; a second diaphragm 9a for transferring pressure to the multiple pressure chambers; and multiple second piezoelectric elements 8 for applying pressure to the second diaphragm. There is also provided an ink jet method including the steps of: applying pressure to one common ink chamber for supplying ink, through the diaphragm by the multiple first piezoelectric elements; and applying pressure to the multiple pressure chambers connected to the common ink chamber and each having the nozzle for jetting ink, through the diaphragm, by the multiple second piezoelectric elements, and jetting ink.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inkjet apparatus and an inkjet method. In particular, the present invention relates to an ink jet apparatus and an ink jet method for performing desired patterning by discharging a liquid containing particles.

  In recent years, with the development of cell engineering and regenerative medical engineering technology, one or two or more types of cells are patterned into a planar shape to produce a printed matter. Alternatively, a technique for creating a three-dimensional structure by laminating these planes is required.

  As an apparatus for performing such patterning, an ink jet apparatus capable of discharging a liquid or a culture liquid (hereinafter, this liquid will be referred to as granular ink) containing particles, particularly cells that are biological particles. There is.

  This ink jet apparatus has one or a plurality of discharge nozzles, and each nozzle is controlled to discharge by an electric signal. The target ink is ejected onto the printing material in accordance with the relative position change between the printing substrate and the nozzle. As a result, it is possible to create a printed material in which a desired granular ink (ink containing particles) is arbitrarily patterned on the printing material.

  On the other hand, when the ink ejected by the ink jet apparatus contains particles, the particles in the ink settle inside the ink jet apparatus if left for a long time. As a result, clogging may occur, resulting in non-ejection. Not only non-ejection, but also change in particle concentration is not preferable because the particle concentration in the liquid pattern on the non-printed material differs from the desired concentration.

  As a technique for improving the change over time in the concentration of particles in a liquid inside the ink jet apparatus as described above, in Patent Document 1, a printer provided with a piezoelectric element that is arranged in an ink container and that gives vibration to granular ink. Inkjet devices have been released.

  The technique of Patent Document 1 will be described with reference to FIGS. FIG. 9A is a cross-sectional view of the ink jet head 99 of Patent Document 1. FIG. FIG. 9B is a cross-sectional view taken along the line A-A ′ of FIG.

  Note that the depth direction in FIG. 9 (a) is the right direction in FIG. 9 (b). The inkjet head 99 includes a housing 2, a supply port 3, a common ink chamber 4, a plurality of nozzles 5 arranged in a row, and a pressure chamber that generates pressure for discharging granular ink 911 (ink containing particles) from the nozzles. 6 at the top. Further, the inkjet head 99 is branched downward from the common ink chamber 4, connected to the pressure chamber 6, connected to the pressure chamber 6, the second piezoelectric element 8 that applies pressure for ejection to the pressure chamber 6, and the common ink chamber. 4, the piezoelectric element 910 for stirring the granular ink 911, the second diaphragm 9 a for transmitting the vibration of the second piezoelectric element 8 to the pressure chamber 6, and the vibration of the piezoelectric element 910 in the common ink chamber 4. It has the 1st diaphragm 9b which transmits.

  With the granular ink 911, the internal particles settle due to the passage of time due to not being discharged for a long time, and the particles 912 settle at the lower part of the common ink chamber 4 to generate the granular ink 911 with a high particle concentration.

  Therefore, by applying an alternating current to the piezoelectric element 910 provided in the common ink chamber 4, the piezoelectric element 910 is vibrated, and the vibration is transmitted to the granular ink 911 through the first vibration plate 9 b, so that the particles are changed over time. The particle concentration of the granular ink 911 can be made uniform by stirring the ink particles 912 inside the ink container where the particle concentration is increased.

Japanese Utility Model Publication No. 4-87251

  The inventor of the present application produced an ink jet head 99 having the structure shown in FIGS. 9A and 9B. A culture solution in which cells were suspended from the supply port 3 was passed as granular ink, and an application experiment on a substrate was performed. As a result, ink was ejected from all the nozzles at first, but after a while, ejection was not performed for some nozzles 5 even though ejection signals were given.

  As a result of investigating the cause, when the discharge signal is not given for creating a desired pattern during the discharge operation, that is, when the discharge operation is not performed for a while, the nozzle 5 thereafter outputs the discharge signal. It was found that no discharge was seen even when applied.

  Further investigation revealed that the granular ink 911 had already settled and aggregated at the inlet of the connecting portion 7 connected to the nozzle 5 that was not ejected during the ejection operation even during the ejection operation. I understood.

  Therefore, the piezoelectric element 910 for agitating the granular ink 911 inside the common ink chamber 4 was simultaneously driven during the ejection operation, and an application operation while agitating the granular ink 911 was attempted. However, since the piezoelectric element 910 stirs the entire granular ink 911 inside the common ink chamber 4, the pressure fluctuation inside the common ink chamber 4 is large, and noise is given to the pressure change in the pressure chamber 6. . As a result, the ink ejection operation became unstable.

  The conventional granular ink 911 is, for example, a pigment dispersion ink or the like, and has a very small size such as a particle size of 10 μm or less, typically 1 μm or less. Therefore, the above problem does not occur and does not become a problem.

  However, the granular ink 911, which is the subject of the present invention, is composed of cells and has a particle size of about 10 μm to 50 μm, so it is very easy to settle, and of course, it cannot be made as fine as pigment particles.

  In addition, even if the time scale is as short as the time required to produce a printed material, if cells are adjacent to each other, adhesion and aggregation occur due to the interaction between the cells. In particular, clogging is likely to occur in a fine flow path such as the connecting portion 7 of the nozzle that is not.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and is to prevent nozzles from being ejected when a liquid containing biological particles such as cells is applied onto a substrate using an inkjet apparatus.

  To achieve the above object, a common ink chamber that supplies ink, a first diaphragm that transmits pressure to the common ink chamber, a first piezoelectric element that applies pressure to the first diaphragm, and a common ink A plurality of pressure chambers connected to the chamber and having nozzles for ejecting ink; a second diaphragm for transmitting pressure to the plurality of pressure chambers; and a plurality of second piezoelectric elements for applying pressure to the second diaphragm Are used.

  Applying a pressure to a common ink chamber for supplying ink via a first diaphragm by a plurality of first piezoelectric elements; and a plurality of nozzles connected to the common ink chamber and ejecting ink An ink jet method including a step of applying pressure to the pressure chamber via the second diaphragm by the second piezoelectric element and discharging the ink is provided.

  By using the ink jet apparatus of the present invention, it is possible to prevent the nozzle from being ejected even when biological particles such as cells are applied.

(A) Schematic diagram of ink-jet head in Embodiment 1, (b) A-A 'cross-sectional view of FIG. 1 (a) (A) Sectional view of the second piezoelectric element in the first embodiment, (b) Perspective view of the second piezoelectric element in the first embodiment of the present invention. (A) A cross-sectional view of a plurality of first piezoelectric elements in the first embodiment, (b) a perspective view of a second plurality of piezoelectric elements in the first embodiment, and (c) a piezoelectric element of an inkjet device according to a conventional technique. Perspective view (A) Schematic diagram of ink jet head of Embodiment 1, (b) Cross section of (a), (c) Cross section when driving channel is driven in (a), (d) In (a) , A sectional view when the driving channel is driven following the driving of the driving channel, a sectional view when the driving channel is driven up to 35 m in (e) and (a), and (f) in FIG. Sectional view when driving is returned to the original state, (g) Sectional view when driving channels 351 and 352 are driven in (a) (A) Schematic diagram of ink-jet head in Embodiment 2, (b) A-A 'cross-sectional view of (a) (A) Schematic diagram of ink jet head according to Embodiment 3, (b) A-A 'cross-sectional view of (a) (A) Schematic diagram showing printing of an inkjet apparatus equipped with the inkjet head of the embodiment, (b) Schematic diagram showing how the remaining part of the coating area is printed after (a). (A) The schematic diagram which shows a mode that the inkjet apparatus carrying the inkjet head of embodiment prints on a dish, (b) The schematic diagram which shows a mode that the remaining part of an application area is printed after (a). (A) Schematic diagram of an ink jet apparatus according to a conventional technique, (b) A-A 'cross-sectional view of (a)

Hereinafter, embodiments will be described with reference to the drawings.
(Embodiment 1)
FIG. 1A to FIG. 4G show the first embodiment.

  FIG. 1A is a front view of an ink jet head 1 used in the ink jet apparatus according to the first embodiment, and FIG. 1B is a cross-sectional view taken along line A-A ′ of the ink jet head 1. Note that the depth direction in FIG. 1A is the right direction in FIG.

  The upper portion of the inkjet head 1 has a housing 2, a supply port 3, a common ink chamber 4, a plurality of nozzles 5 arranged in a row, and a pressure chamber 6 that generates pressure for ejecting ink from the nozzles.

  The lower part of the inkjet head 1 includes a connecting portion 7 that branches from the common ink chamber 4 and connects to the pressure chamber 6, a second piezoelectric element 8 that applies pressure for ejection to the pressure chamber 6, and a second piezoelectric element 8. A second vibration plate 9 a that transmits vibration to the pressure chamber 6 and a first piezoelectric element 10 for stirring the granular ink 11 in the common ink chamber 4 are provided. Further, a first diaphragm 9 b that transmits the vibration of the first piezoelectric element 10 to the common ink chamber 4 is included.

  The first piezoelectric element 10 has a structure different from that of the conventional piezoelectric element 910 (described later). In the present embodiment, the common ink chamber 4, the nozzle 5, the pressure chamber 6, and the connection portion 7 are collectively referred to as an ink flow path.

<Case 2>
The housing 2 according to the embodiment includes a supply port 3 that supplies ink into the ink jet head, a common ink chamber 4 that stores the supplied ink, and a plurality of nozzles that discharge the granular ink 11 on the substrate to be printed. 5. A connecting portion 7 that is connected to the plurality of nozzles, branches from the number of pressure chambers 6 corresponding to the number of nozzles that generate pressure for ejecting ink, and the common ink chamber 4, and is connected to the plurality of pressure chambers 6. It is formed with.

  The material of the housing 2 is not particularly limited as long as it is not affected by the ejected ink, and a metal such as stainless steel, an inorganic material such as glass or silicon, or an organic material such as resin can be used. However, it is preferable that the inside can be visualized in order to confirm whether or not ink clogging has occurred in the common ink chamber 4, the nozzle 5, the pressure chamber 6, the connection portion 7, and the like that are ink flow paths. For this reason, it is preferable to use a translucent material such as glass or transparent resin. In view of ease of processing, it is preferable to be made of a transparent resin.

  Examples of the transparent resin include acrylic resins such as PMMA, polyethylene terephthalate resin, polycarbonate resin, polyvinyl chloride resin, polystyrene resin, and cycloolefin resin.

  Furthermore, the ink jet head 1 needs to be sterilized before the ink is passed through the ink flow path of the ink jet head 1 produced. For this reason, it is necessary to endure the chemical | medical agent for sterilization, or to endure the heat | fever of autoclave sterilization. Moreover, when it becomes necessary to observe the cell inside the inkjet head 1 with a microscope or the like, it is preferable that the substance between the cell and the lens has low fluorescence. Examples of materials that can satisfy the required properties such as heat resistance, chemical resistance, and low autofluorescence include cycloolefin resins, but are not limited thereto.

  Further, as a method of processing the ink flow path in the housing 2, any processing method such as cutting, injection molding, imprinting, casting, laser processing, drilling, stereolithography, processing by a 3D printer, etc. Can be selected.

  Further, in FIG. 1B, the casing 2 is arranged on both sides so as to be divided into the casing 2a and the casing 2b and sandwich the second diaphragm 9a and the first diaphragm 9b. Among them, the ink flow path is not formed in the housing 2b, that is, the portion on the back side of the paper surface in FIG. 1A, and may be arranged as necessary to ensure the strength of the housing. . In addition, the same material and processing method as those of the housing 2a may be used for the arrangement.

  In addition, a coating that inhibits the adhesion of cells, such as MPC polymer, can be applied to the inside of the ink flow path.

<Supply port 3>
The supply port 3 is used when the granular ink 11 is injected into the common ink chamber 4 from the outside via a tube (not shown) or the like. When ink is not being injected, it may be sealed by a valve or the like so that it does not receive pressure from the outside, or may be connected to an air release or a pressure pump. In addition, although the supply port 3 is one in Fig.1 (a), you may install two or more supply ports 3. FIG. By providing a plurality of supply ports 3, it is possible to provide an ink discharge port, an air vent port during ink purging, and an ink inlet / outlet port when ink circulation is performed.

<Second diaphragm 9a, first diaphragm 9b>
The second diaphragm 9a and the first diaphragm 9b that form one surface of the ink flow path by being bonded to the housing 2 are made of a thin metal plate such as a thin resin plate or a nickel electroformed film. Can be formed.

  The second diaphragm 9a, the first diaphragm 9b, and the housing 2 may be an adhesive such as a thermosetting adhesive, a two-component mixed adhesive, or an ultraviolet curable adhesive, or thermocompression bonding, laser crimping, It can be bonded by ultrasonic pressure bonding. Among these, in the case of bonding by thermocompression bonding, it is preferable that the glass transition points of the second diaphragm 9a and the first diaphragm 9b and the housing 2 are the same or close to each other. The material of the diaphragm 9b and the material of the housing 2 are preferably the same.

<Second piezoelectric element 8>
The second piezoelectric element 8 will be described with reference to FIGS. 2 (a) and 2 (b). 2A is a schematic cross-sectional view of the second piezoelectric element 8 seen from the same direction as FIG. 1B, and FIG. 2B is a perspective view of the second piezoelectric element 8. FIG. The cross section AA ′ in FIG. 1A is a plane of the cross section 20 illustrated by a dotted line in FIG. For ease of viewing, the second diaphragm 9a is not shown in FIG.

  In FIG. 2A, the second piezoelectric element 8 is formed by laminating a piezoelectric body 22 such as lead zirconate titanate on which an internal electrode 21a and an internal electrode 21b are formed, and then on the side surface of the laminated piezoelectric body 22 layer. Of these, the front electrode 23 and the back electrode 24 are formed on both surfaces where the internal electrodes 21 a and 21 b are exposed to face each other, and are fixed on the base 29.

  In response to the input signal, the second piezoelectric element 8 vibrates the second diaphragm 9a bonded to the pressure chamber 6.

  2B, in the second piezoelectric element 8, drive channels 25a and drive channels 25b corresponding to the number of a plurality of nozzles are alternately arranged, and a groove 26 exists between the channels. doing. The groove 26 is formed when the second piezoelectric element 8 is integrally formed and then dicing is performed in order to divide the plurality of channels. The gap between each drive channel 25a and drive channel 25b is defined as follows. The grooves 26 are separated and insulated.

  Further, the connection electrode 27 is connected to the drive channel 25a. The drive channel 25a is bonded to the second diaphragm 9a at a position facing the pressure chamber 6 in FIG. The drive channel 25b is not connected to the connection electrode 27, and is disposed between two adjacent pressure chambers 6 as shown in FIG. It is bonded to the second diaphragm 9a located at a location facing the portion of the housing 2 that partitions the two pressure chambers 6 to form a dummy channel.

  That is, the number of drive channels 25 a is equal to the number of the plurality of nozzles 5, and the number of dummy drive channels 25 b is one or more than the number of the plurality of nozzles 5.

  The widths of the drive channels 25a and 25b and the groove 26 are appropriately set according to the width of the pressure chamber 6 and the installation interval, but the width of the drive channel 25b may be different from the width of the drive channel 25a.

  Further, among the four sides of the surface electrode 23 in FIG. 2B, a notch 28 having a diagonal shape or a rectangular shape is ground on the side in the root direction of the connection electrode 27 (below the paper surface in FIG. 2B). It is formed by processing. The surface electrode 23 is electrically separated by the notch 28 and the groove 26 to form a drive channel 25a and a dummy drive channel 25b, and the back electrode 24 without the notch is electrically connected to become a common electrode. ing.

<First piezoelectric element 10>
The first piezoelectric element 10 will be described with reference to FIGS. 3 (a) to 3 (c). 3A is a schematic cross-sectional view of the first piezoelectric element 10 viewed from the same direction as FIG. 1B, and FIG. 3B is a perspective view of the first piezoelectric element 10. The cross section AA ′ in FIG. 1A becomes the plane of the cross section 30 illustrated by the dotted line in FIG. In addition, illustration of the 1st diaphragm 9b is abbreviate | omitted in FIG.3 (b).

  FIG. 3C is a cross-sectional view taken along the line A-A ′ of FIG. 9A, and is a perspective view of the piezoelectric element 910 of the inkjet head 99 having a conventional structure.

  The configuration and manufacturing method of the internal electrode 31a, the internal electrode 31b, the piezoelectric body 32, the front surface electrode 33, the back surface electrode 34, and the base 39 of the first piezoelectric element 10 in FIG. It is the same. Like the second piezoelectric element 8, the vibration on the base 39 side is fixed, and only the first diaphragm 9b bonded to the common ink chamber 4 vibrates.

  The total size of the vibration surface of the first piezoelectric element 10 is not particularly limited as long as it is approximately the same as the size of the common ink chamber 4. And the magnitude of vibration for the same input voltage may be the same as or different from those of the second piezoelectric element 8.

  In FIG. 3B, the first piezoelectric element 10 has a plurality of drive channels 35 arranged in a row, and a groove 36 exists between each channel. The groove 36 is formed by dicing, and the groove 26 of the second piezoelectric element 8 is the same.

  The plurality of drive channels 35 are separated and insulated by the grooves 36. Further, unlike the second piezoelectric element 8 having a dummy channel, a connection electrode 37 is connected to each of the drive channels 35 separated by the grooves 36 so as to face the common ink chamber 4 in FIG. A drive channel 35 is formed by being attached to the first diaphragm 9b at the position.

  A drive voltage is applied to each drive channel 35 from a signal input device (not shown) via a connection electrode 37, and each drive channel 35 can be driven independently.

  In addition, while the drive voltage is being applied to a certain channel among the drive channels 35, the drive voltage can be applied to another channel at different timings. That is, it is possible to drive by changing the phase of each channel.

  The number of drive channels may be the same as or different from the number of drive channels of the second piezoelectric element 8 as long as it is plural.

  The notch 38 has an oblique shape or a rectangular shape as shown in FIG. 3B and is formed by grinding or the like before the first piezoelectric element 10 is diced to form the groove 36. .

  On the other hand, the piezoelectric element 910 of the ink jet head 99 having the conventional structure shown in FIG. 3C has a configuration of an internal electrode, a piezoelectric body, a front surface electrode, a back electrode, a base, and a production method thereof as shown in FIG. Although it is the same as that of the first piezoelectric element 10 shown in FIG. 3B, the groove 36 does not exist and the channel 935 is one.

  Since there is only one channel 935, only one connection electrode 937 is required. However, since the channel 935 vibrates the entire ink chamber, the size of the channel 935 increases and the amount of current required for driving increases. Therefore, a plurality of connection electrodes 937 may exist for the same channel 935 as a countermeasure for voltage drop.

  Since there is one channel 935, the piezoelectric element 910 vibrates as a whole in response to one drive voltage input, and the entire common ink chamber 4 is made uniform via the first diaphragm 9b of FIG. 9B. It has a function to vibrate and stir the entire granular ink 11 inside.

  Hereinafter, the configuration of the common ink chamber 4, the nozzle 5, the pressure chamber 6, and the connection portion 7 that form the ink flow path will be described with reference to FIGS. 1A and 1B.

<Nozzle 5>
The nozzle 5, which is a part of the ink flow path, may be formed directly in the casing, or a connection port is formed on the downstream side of the pressure chamber 6, and a nozzle plate in which the nozzle 5 is separately formed, It can also be formed by installing in the lower part and connecting to the pressure chamber 6 through this connection port.

  The number of nozzles 5 in the ink jet apparatus according to the embodiment is plural, but the number is not particularly limited as long as it is 2 or more, but depending on the interval between adjacent nozzles 5, if there are too many nozzles, the number of nozzles 5 is not limited. The size of the body 2 increases. An object printed by the ink jet apparatus according to the embodiment is a biological sample, and the size thereof is about 1 to 20 cm. Accordingly, it is not preferable that the number of nozzles is too large because it is not appropriate for the size of the substrate. The number of nozzles 5 is 2 to 200, typically 2 to 50.

  The diameter of the nozzle 5 (the diameter when the nozzle cross section is not circular is regarded as a circle) is 20 to 150 microns, typically 30 to 100 microns. If the diameter is smaller than this, cell clogging occurs. If it is larger than this, problems such as ink dripping or ejection becoming unstable may occur. The diameter of the nozzle 5 is appropriately set according to the ink viscosity, the size, density, and coating amount of the cells in the granular ink.

  The processing method of the nozzle 5 is a processing by a drill, a method in which a needle-shaped mold is pushed in, a method by a laser, or a groove-shaped processing is applied to the housing 2 and the second diaphragm 9a is bonded together. Although the method of forming a pipe | tube between the surfaces of a groove | channel etc. can be mentioned, It is not limited to these.

<Pressure chamber 6>
The pressure chamber 6 which is a part of the ink flow path is formed between the downstream side of the connection portion 7 of the housing 2 and the nozzle 5, and the second surface is formed on one surface (the surface on the back side in FIG. 1A). The vibration plate 9a is bonded, and pressure can be applied to the granular ink 11 inside the pressure chamber 6 by the vibration of the second piezoelectric element 8 via the second vibration plate 9a.

<Connection 7>
The connection portion 7 which is a part of the ink flow path has a function of distributing ink from the common ink chamber 4 to the plurality of pressure chambers 6, and discharge pressure generated in the pressure chamber 6 is applied to the common ink chamber 4 side. It also has a function to prevent escape. For this reason, the portion having the smallest cross-sectional area in the connecting portion 7 is designed to be smaller than the cross-sectional area of the pressure chamber 6. However, if the cross-sectional area is too small, clogging of the cells in the granular ink 11 occurs. It is set appropriately according to the size and concentration of the cells inside.

<Common ink chamber 4>
The common ink chamber 4 which is a part of the ink flow path stores the granular ink 11 supplied from the supply port 3 and distributes and supplies the granular ink 11 to a plurality of connected connection portions 7. It has a function. A first diaphragm 9b is bonded to one surface of the common ink chamber 4 (the surface on the back side of the paper in FIG. 1A). The granular ink 11 inside the common ink chamber 4 can be swung by the vibration of the plurality of drive channels 35 of the plurality of first piezoelectric elements 10 disposed via the first diaphragm 9b.

<Process>
A nozzle non-ejection prevention mechanism using vibration of the drive channel 35 will be described with reference to FIGS.

  FIG. 4A shows channel names given to the nozzle 5, the pressure chamber 6, the connection portion 7, and the first piezoelectric element 10 in FIG. From the left side of the page, nozzles 51, 52,... 5n, 5 (n + 1), pressure chambers 61, 62,... 6n, 6 (n + 1), connection portions 71, 72,. , 7 (n + 1)... Are connected to each other. In addition, drive channels 351, 352,... 35m, 35 (m + 1).

  However, the pitch of the nozzle 5, the pressure chamber 6, and the connection portion 7 and the pitch of the drive channel 35 may be equal or different. Therefore, the drive channel 35n is not necessarily arranged immediately above the nth nozzle 5n, the pressure chamber 6n, and the connecting portion 7n from the left side of the drawing. Here, the nth nozzle 5n, the pressure chamber 6n, and the connecting portion from the left are not necessarily arranged. It is assumed that a drive channel 35m is arranged immediately above 7n.

For example, when the same piezoelectric element is used for the second piezoelectric element 8 and the first piezoelectric element 10,
The dummy channel of the second piezoelectric element 8 can also be a drive channel in the first piezoelectric element 10. Thus, the drive channels 35 (2n-1) and 35 (2n) are arranged immediately above the nth nozzle 5n, the pressure chamber 6n, and the connection portion 7n from the left.

  FIG. 4B is a cross-sectional view taken along the line B-B ′ of FIG. 4A, as viewed from the direction in which the supply port 3 of FIG. Further, each drive channel 35m of the first piezoelectric element 10 is displaced in the direction extending from 0 as the maximum voltage is applied, and the first diaphragm 9b located immediately above the drive channel 35m can be pushed up.

  In addition, by applying a voltage between 0 and the maximum voltage in advance and changing the voltage from that voltage to a larger or smaller voltage, pushing up or lowering the first diaphragm 9b located immediately above the drive channel 35m is also reduced. You can also.

  Here, as an example, the granular ink 11 containing cells is put in the inkjet head 1, and among the nozzles of the inkjet head 1, nozzles 5 (n + 1), nozzles 5 (n + 1), nozzles 5 (n + 1), and so on. That is, the case where the coating operation is performed on the substrate using only the nozzle in the right region of the head is shown.

  First, when ink is injected from the supply port 3 in FIG. 4A, the common ink chamber 4 is filled with the granular ink 11 and is common as in the granular ink 11 in FIGS. 4A and 4B. Particles are uniformly distributed inside the ink chamber 4.

  First, in this state, ejection is performed from nozzles 5 (n + 1), 5 (n + 2)... Among the nozzles of the inkjet head 1 without using the first piezoelectric element 10. Then, of the granular ink 11 in the common ink chamber 4, only the granular ink 11 directly above the connecting portions 7 (n + 1), 7 (n + 2)... Is connected to the connecting portions 7 (n + 1), 7 (n + 2). The liquid flows into the common ink chamber 4 on the right side, and new granular ink 11 is supplied from the supply port 3. However, the granular ink 11 immediately above the connecting portions 71, 72,..., 7n remains stationary.

  FIG. 4C shows a state in which the first piezoelectric element 10 is operated in the state of FIG. 4B when discharging is performed from the nozzles 5 (n + 1), 5 (n + 2). is there.

  In the state where the granular ink 11 immediately above the connecting portions 71, 72,..., 7n is stationary, the drive channel 351 in FIG. Then, a positive pressure is applied to the granular ink 11 directly above the drive channel 351 via the first diaphragm 9b, and the pressure is pushed out to the drive channel 352 side, so that the neighboring cells 41 move to the right side.

  FIG. 4D is a diagram in which the drive channel 352 is further pushed up from FIG. As in FIG. 4C, a positive pressure is applied to the granular ink 11 directly above the drive channel 352 via the first diaphragm 9b, and the positive pressure is pushed out to the drive channel 353 side, so that the neighboring cells 41 move to the right side.

  Similarly, when the drive channels 354, 355,... Are sequentially pushed up, the granular ink 11 cells move to the right.

  FIG. 4E shows a state where the drive channel of the first piezoelectric element 10 is sequentially pushed up to the drive channel 35m in this way.

  By sequentially pushing up from the drive channel 351 to 35 m, a positive pressure is applied to the granular ink 11 directly above the first diaphragm 9 b and pushed out to the drive channel 35 (m + 1) side. Move to. That is, the cell 4m moves to the right side of the common ink chamber 4 and flows into the pressure chamber side from the connection portions 71, 72,..., 7n in FIG.

FIG. 4 (f) shows the drive channel 351 further lowered from FIG. 4 (e).
By pulling down the drive channel 351, a negative pressure is applied to the granular ink 11 directly above the drive channel 351 via the first diaphragm 9b, and the ink is drawn from the drive channel 352 side, and a part thereof is shown in FIG. Ink is also drawn from the supply port 3 side. Further, the ink is drawn from the supply port 3 each time by sequentially lowering the drive channels 352, 353,..., 35m, and the state returns to the state shown in FIG.

  As described above, by repeating the operations of FIG. 4B to FIG. 4F with the plurality of first piezoelectric elements 10 different from the conventional one, the connection portions 71, 72,. The granular ink 11 directly above 7n is moved immediately above the connecting portions 7 (n + 1), 7 (n + 2)..., And the nozzles 5 (n + 1), 5 through the connecting portions 7 (n + 1), 7 (n + 2). (N + 2)... For this reason, the cells of the granular ink 11 immediately above the connecting portions 71, 72,..., 7n do not aggregate and settle, and then the ejection signals are sent to the nozzles 51, 52. Even if it is sent, no discharge will occur.

  In addition, the first piezoelectric element 10 in FIGS. 4A to 4F is selective only to the connection portions 71, 72,..., 7n connected to the nozzles that are not ejecting and the vicinity thereof. Pressure can be applied. Further, since each drive channel is driven in a distributed manner on the time axis, the pressure fluctuation in the common ink chamber 4 is small, and the influence on the ejection operation is small.

  4B to FIG. 4F, the drive channels 351 to 35m are all pushed up and then the drive channel 351 is pulled down. However, before the drive channel 35m is pushed up, a certain amount of drive channels are pushed up. At this stage, the driving channel 351 may start to be pulled down. Further, in this state, before the drive channel 35m is fully pushed up, the drive channel 351 once pulled down may be pushed up again sequentially. Conversely, the drive channel 351 may be pulled down after a certain period of time has elapsed after all the drive channels 351 to 35m have been pushed up. That is, there is no particular limitation on the magnitude relationship between the time until the drive channels 351 to 35n are sequentially pushed up (vibration cycle of the drive channel group) and the cycle of driving one channel (vibration cycle of individual drive channels).

  Further, in the operations shown in FIGS. 4B to 4F, an example in which the drive channels 351 to 35m are all pushed up is shown. However, as described above, a voltage is applied to the drive channels in advance. By reducing the voltage, the first diaphragm 9b can be pulled down to apply a negative pressure to the common ink chamber 4.

  Therefore, as shown in FIG. 4G, the drive channel 351 can be pushed down, or the adjacent drive channel 352 can be pulled down at the same time or substantially simultaneously. When driven in this way, a positive pressure is generated immediately above the drive channel 351 and a negative pressure is generated immediately above the adjacent drive channel 352, so that the granular ink 11 is efficiently moved to the drive channel 352 side. Can be made. Furthermore, since positive and negative pressures are simultaneously generated in the vicinity and cancel each other, pressure fluctuations throughout the common ink chamber 4 are further reduced, which is more preferable.

In the above example, the driving procedure of the first piezoelectric element 10 for ejecting only the nozzle on the right side of the head is shown. However, the discharge nozzle pattern is not limited to this. For example, the drive channels on both sides of the first piezoelectric element 10 can be driven symmetrically in order to discharge only the nozzle in the center of the head. Therefore, the driving procedure of the driving channel is not limited to the above example. Moreover, there is no restriction | limiting in particular in the drive voltage waveform applied to the 1st piezoelectric element 10, A sine wave, a triangular wave, a rectangular wave, etc. can be applied.
As described above, the first embodiment solves the problem of the present application.

(Embodiment 2)
5 (a) to 5 (b) show the second embodiment. FIG. 5A is a front view of an ink jet head 501 used in the ink jet apparatus of the second embodiment. FIG. 5B is a cross-sectional view of the inkjet head 501 along AA ′. Note that the depth direction in FIG. 5A is the right direction in FIG.

  The first embodiment is different from the diaphragm 509. Two diaphragms become one diaphragm. The inkjet head 501 has a housing 502, a supply port 503, a common ink chamber 504, a plurality of nozzles 505 arranged in a row, a pressure in which one surface is on the same plane as one surface of the common ink chamber 504. A chamber 506 is provided. The ink jet head 501 is branched from the common ink chamber 504 at a lower portion thereof, a connection portion 507 connected to the pressure chamber 506, a second piezoelectric element 508 that applies pressure for ejection to the pressure chamber 506, and the common ink chamber 4. The vibrations of the plurality of first piezoelectric elements 510, the second piezoelectric elements 508, and the plurality of first piezoelectric elements 510 for stirring the granular ink 511 in the inside are transmitted to the pressure chamber 506 and the common ink chamber 504, respectively. A diaphragm 509 is provided.

  As shown in FIG. 5A, one surface of the common ink chamber 504 and one surface of the pressure chamber 506 are arranged on the same plane (the surface in the depth direction in FIG. 5A). As a result, as shown in FIG. 5B, it is possible to arrange a vibration plate 509 that can transmit pressure to both the common ink chamber 504 and the pressure chamber 506.

  The first piezoelectric element 510 is located in a portion corresponding to the common ink chamber 504 of the vibration plate 509. A second piezoelectric element 508 is located in a portion corresponding to the pressure chamber 506 of the vibration plate 509.

  By adopting the second embodiment, the inkjet head 501 can include the two piezoelectric elements of the second piezoelectric element 8 and the first piezoelectric element 10, and the diaphragm 509 can be integrated. While simplifying the manufacturing process 501, the same function as that of the first embodiment can be provided.

(Embodiment 3)
6 (a) to 6 (b) show a third embodiment. FIG. 6A is a front view of an inkjet head 601 used in the inkjet apparatus of the third aspect. FIG. 6B is a cross-sectional view of the inkjet head 601 along AA ′. 6A is the right direction of FIG. 6B.

  Unlike the first and second embodiments, the depression 607b is a feature.

  The inkjet head 601 is provided with a housing 2, a supply port 3, a common ink chamber 4, a plurality of nozzles 5 arranged in a row, and a pressure on which one surface is flush with one surface of the common ink chamber 4. It has a chamber 6. The inkjet head 601 has a connection portion 607a branched from the common ink chamber 4 and connected to the pressure chamber 6, a depression 607b provided on the common ink chamber 4 side of the connection portion 607a, and a discharge to the pressure chamber 6. And a plurality of first piezoelectric elements 10 for stirring the granular ink 11 in the common ink chamber 4. Further, the vibration plate 509 transmits vibrations of the second piezoelectric element 8 and the plurality of first piezoelectric elements 10 to the pressure chamber 6 and the common ink chamber 4, respectively.

  The granular ink 11 is swung by the first piezoelectric element 10 in the common ink chamber 4 of FIG. For this reason, the amount of cells contained in the granular ink 11 in the vicinity of the connecting portion 7 is constantly changing. Depending on the case, there is a possibility that the concentration required for ejection is instantaneously lowered.

  Therefore, as in the third embodiment, the internal granular ink 11 can be made less susceptible to the influence of the oscillation at the entrance on the common ink chamber 4 side of the connection portion 607a in FIG. By providing the depression 607b and storing a certain amount of granular ink 11 as a buffer, the concentration of cells flowing into the connection portion 607a from the common ink chamber 4 oscillated by the first piezoelectric element 10 is temporally measured. Variation can be reduced.

  The size of the recess 607b is not particularly limited except that the width is smaller than the nozzle pitch, but if it is too small, the function as a buffer is not exhibited. On the other hand, if it is too large, cell sedimentation and aggregation occur in the recess 607b connected to a channel not used for ejection.

  The size of the recess 607b in the width direction (nozzle row direction) is typically 0.1 to 2 millimeters. The size in the depth direction (connecting portion direction) of the recess 607b is about 0.1 to 10 times the size in the width direction, but is not limited thereto.

  Further, the shape of the recess 607b is not particularly limited, and the entrance on the common ink chamber 4 side is in the left-right direction in FIG. 6A and in the left-right direction in FIG. 6B, that is, in the depth direction in FIG. The shape may be wide, and the shape may be an arbitrary shape such as a quadrangular pyramid, a half cone, a rectangular parallelepiped, a half cylinder, a half trumpet shape, and a half bell shape.

(Embodiment 4)
FIG. 7A to FIG. 7B are schematic views of an ink jet apparatus equipped with the ink jet head 1 shown in the first to third embodiments.

  In FIG. 7A, the inkjet head 1 receives ink supply from an ink tank 703 through a pipe 702, and the granular ink is applied to a coating area 705 on a printing substrate 704 disposed on a stage (not shown). The print pattern 706 is formed by the relative movement in the scanning direction 707 of the stage. When the width of the application area 705 is wider than the application width of the inkjet head 1, the printing pattern 706 is formed by discharging from the entire application width of the inkjet head 1, that is, all nozzles of the inkjet head 1 in the stage of FIG. Form.

  However, the width of the application area 705 is wider than the application width of the inkjet head 1. For this reason, when printing the remaining part of the application area 705 that could not be printed at once as shown in FIG. 7B, the remaining width of the application area 705 becomes narrower than the application width of the inkjet head 1. As a result, in the inkjet head 1, the remaining print pattern 706 is applied only with the nozzles on the right side of the region 708, and the nozzles on the left side of the region 708 do not perform the ejection operation.

  If the target object to be formed with a print pattern is a printing device whose purpose is to continue printing a certain size, such as a flat panel display, a document on paper, or an image, the width of the coating area at the design stage Accordingly, the application width of the inkjet head can be designed so that the application width is not wasted.

  However, since the object of a printed pattern in the field of cell engineering or regenerative medical engineering, for example, the size of a cell sheet changes each time, it is not possible to design an optimum application width of an inkjet head in advance. For this reason, nozzles that are temporarily not used for ejection frequently occur in the printing operation.

  In addition, the use of an ink jet apparatus equipped with the ink jet head 1 according to the first to third aspects is useful because a nozzle that is not temporarily used for ejection does not become non-ejection.

  Further, in FIGS. 7A to 7B, a flat rectangular shape, which is a general shape of a printed material, is used as an example of a printed substrate. However, the printed substrate 704 in the fields of cell engineering and regenerative medical engineering often has a circular shape with side walls, that is, a shallow cylindrical shape with a bottom surface, such as a petri dish, a dish, and a well.

  As an example, a case where printing is performed on the application area 805 on the bottom surface of a circular dish 804 as shown in FIG.

  The inkjet head 1 smaller than the diameter of the dish 804 is inserted and brought close to the bottom surface, and is rotated in a rotation direction 807 on a stage (not shown) with the center of the dish 804 as an axis. This makes it possible to create a concentric circular print pattern 806 in the application area 805 on the bottom surface of the dish 804.

  Further, when the application width of the inkjet head 1 is narrower than the application area 805, as shown in FIG. 8 (b), the inkjet head 1 is shifted outside so as not to touch the side wall in the dish 804. The remaining portion of the application area 805 can be printed using only the nozzles in the region (left side of the paper in FIG. 8B).

  When application is performed concentrically as described above, the printing speed varies depending on the distance between the center of the rotating shaft of the dish 804 and the nozzle, and the ink discharge amount also varies from nozzle to nozzle. That is, the nozzle near the center of the rotation axis of the dish 804 has a low peripheral speed, and the ink discharge amount per unit time is smaller than that of the nozzle that is far from the center of the rotation axis. For this reason, since the flow of the granular ink is reduced in the common ink chamber immediately above the nozzle near the center of the rotation axis of the dish 804, sedimentation / aggregation is likely to occur.

  Therefore, the ink jet apparatus equipped with the ink jet head 1 according to the embodiment is useful as an ink jet apparatus in the field of cell engineering or regenerative medical engineering because it can prevent sedimentation and aggregation of granular ink in a common ink chamber.

  As described above, the ink jet apparatus equipped with the ink jet head shown in the first to fourth aspects is suitably used for printing granular ink containing particles, particularly cells that are biological particles.

Examples of the particles contained in the granular ink include eukaryotes such as cells and fungi, prokaryotes such as bacteria, proteins, and organelles such as nuclei and mitochondria. Examples of cells include cardiomyocytes, vascular endothelial cells, myoblasts, fibroblasts, epidermal cells, hepatocytes, skeletal muscle cells, osteoblasts, nerve cells, pigment cells, smooth muscle cells, fat cells, bone cells And chondrocytes. The typical concentration of cells contained in the granular ink is 1 × 10 ⁵ cells / ml to 1 × 10 ⁷ cells / ml, but is not limited thereto.

(Note)
Embodiments 1 to 4 can be combined.

The ink jet device according to the embodiment is useful because it is possible to prevent the nozzle from being non-discharged when a liquid containing biological particles such as cells is applied onto the printing material.

DESCRIPTION OF SYMBOLS 1,501 Inkjet head 2,502 Case 2a Case 2b Case 3,503 Supply port 4,504 Common ink chamber 5, 5n, 505 Nozzle 6, 6n, 506 Pressure chamber 7, 507, 7n Connection portion 8,508 Second piezoelectric element 9a Second diaphragm 9b First diaphragm 10, 510 First piezoelectric element 11, 511 Granular ink 20 Cross section 21a Internal electrode 21b Internal electrode 22 Piezoelectric body 23 Surface electrode 24 Back electrode 25a Drive Channel 25b Drive channel 26 Groove 27 Connection electrode 28 Notch 29 Base 30 Cross section 31a Internal electrode 31b Internal electrode 32 Piezoelectric body 33 Surface electrode 34 Back surface electrode 35, 35n Drive channel 36 Groove 37 Connection electrode 38 Notch 39 Base 41 Cell 51 Nozzle 61 Pressure chamber 71 Connection part 351, 352, 353, 354 Drive channel 09 Diaphragm 601 Inkjet head 607a Connection portion 607b Depression 702 Pipe 703 Ink tank 704 Printed substrate 705 Application area 706 Print pattern 707 Scan direction 708 Area 804 Dish 805 Application area 806 Print pattern 807 Rotation direction 808 Area 99 Inkjet head 910 Piezoelectric element 911 Granular ink 912 Particles 935 Channel 937 Connection electrode

Claims (9)

A common ink chamber for supplying ink;
A first diaphragm for transmitting pressure to the common ink chamber;
A first piezoelectric element that applies the pressure to the first diaphragm;
A plurality of pressure chambers connected to the common ink chamber and having nozzles for discharging the ink;
A second diaphragm for transmitting pressure to the plurality of pressure chambers;
An inkjet apparatus comprising: a second piezoelectric element that applies the pressure to the second diaphragm; and a plurality of the first piezoelectric elements provided for the common ink chamber. The inkjet apparatus according to claim 1, wherein the first diaphragm and the second diaphragm constitute one diaphragm.
An inkjet apparatus characterized by that. 3. The ink jet apparatus according to claim 1, wherein depressions are provided at inlets on a side of the common ink chamber of a plurality of connection portions communicating with the plurality of pressure chambers and the common ink chamber. The inkjet device according to any one of claims 1 to 3, wherein the plurality of first piezoelectric elements can be individually driven. The inkjet device according to claim 1, wherein the plurality of first piezoelectric elements can be driven with a phase difference. The inkjet apparatus according to claim 1, wherein the ink to be applied contains particles. The inkjet apparatus according to claim 6, wherein the particles are cells. Applying a pressure to a common ink chamber for supplying ink via a first diaphragm by a plurality of first piezoelectric elements;
Applying a pressure to a plurality of pressure chambers connected to the common ink chamber and having nozzles for discharging the ink through a second diaphragm by a second piezoelectric element, and discharging the ink; Ink jet method characterized by including these. Applying a pressure to a single common ink chamber for supplying ink via a diaphragm with a plurality of first piezoelectric elements;
A step of applying pressure to the plurality of pressure chambers connected to the common ink chamber and having nozzles for discharging the ink through the diaphragm by a plurality of second piezoelectric elements, and discharging the ink; Ink jet method characterized by including these.

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