JP2003094662A - Droplet discharging device and ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet discharging device capable of atomizing discharging droplets without miniaturizing a nozzle or the like, that is, capable of discharging smaller droplets with a nozzle of the same size, and also to provide an ink-jet printer using the device. SOLUTION: There are provided a plurality of nozzles, discharging means for discharging the droplets from the nozzles, supply channels for supplying liquid to the nozzles, pressure adjusting means in the supply channels, and gas channels for introducing gas into the nozzles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a liquid droplet ejecting apparatus used for an ink jet recording head or the like, and more specifically, ejects minute liquid droplets without miniaturizing nozzles. The present invention relates to a droplet discharge device capable of

[0002]

2. Description of the Related Art A thermal ink jet is used in various printers in which a part of ink is rapidly vaporized by heating with a heater and an ink droplet is ejected from a nozzle by its expansive force and the like (Japanese Patent Laid-Open No. 48-48). 9622 publication,
54-51837, etc.). In addition, MEMS (Micro Erectronic Machine Syste) that uses static electricity
m), or vibrating the diaphragm with a driving means such as a piezo element,
Printers that use an inkjet that ejects ink droplets from the nozzles by the energy are also known (Japanese Patent Laid-Open Nos. 11-207956 and 11-309850).
See each bulletin, etc.).

In recent years, higher speed has been required for such image recording by ink jet. As a method for speeding up image recording by inkjet, it is important to improve the inkjet recording head such as improvement of ejection frequency and number of nozzles and shorten fixing time (drying rate). Further, as a method of improving the fixing speed and shortening the fixing time, the amount of ink droplets per droplet is reduced (droplet miniaturization), and the landing droplets per pixel (minimum unit of image expression) It is known that the method of increasing the number is effective.

[0004]

Needless to say, the size of a droplet per ink ejection is greatly affected by the size of the nozzle. Therefore, the miniaturization of ink droplets
This can be achieved by miniaturizing the nozzle. However, there is a limit to the processing accuracy in miniaturizing the nozzles, and there is a limitation in miniaturizing the ink droplets while maintaining sufficient accuracy.

An object of the present invention is to solve the above-mentioned problems of the prior art, and is a droplet discharge device used in an ink jet recording head or the like, which discharges droplets without miniaturizing nozzles and the like. (EN) Provided are a droplet discharge device that can achieve miniaturization, that is, a droplet discharge device that can discharge finer droplets with the same size nozzle, and an inkjet printer that uses this droplet discharge device. is there.

[0006]

In order to achieve the above object, a droplet discharge device of the present invention comprises a plurality of nozzles, discharge means for discharging droplets from the nozzles, and liquid supply to the nozzles. A supply path and a pressure adjusting means in the supply path,
There is provided a droplet discharge device having a ventilation path for introducing gas into the nozzle.

In such a droplet discharge device of the present invention, the pressure adjusting means pressurizes the inside of the supply passage to supply the liquid to a predetermined height of the nozzle, and then,
By reducing the pressure in the supply passage by the pressure supply means, gas is introduced into the nozzle from the ventilation passage, and the liquid in the nozzle is divided into the discharge port side and the supply passage side by this gas, and in this state, It is preferable that the liquid on the ejection port side in the nozzle is ejected as liquid droplets by driving the ejection means, and at least one end of the inner surface of the ventilation path on the nozzle side and at least one of the ventilation path openings. It is preferable that the inner surface of the nozzle including the portion is annularly liquid-repellent with respect to the discharged liquid, and further, it is preferable to have a pump for introducing gas into the nozzle from the ventilation passage.

Further, the ink jet printer of the present invention provides an ink jet printer using the above-mentioned liquid droplet ejection apparatus of the present invention as an ink jet recording head.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a droplet discharge device of the present invention and an inkjet printer of the present invention using the droplet discharge device will be described in detail with reference to the preferred embodiments shown in the accompanying drawings.

In the following description, the droplet discharge apparatus of the present invention is a so-called thermal ink jet ink jet in which nucleate boiling of ink is generated by heating with a heater, and the expansion force and bursting force of the ink eject the ink from a nozzle. The example used for the recording head is used.

However, the present invention is not limited to this, as long as it has a nozzle, a discharge means for discharging a droplet from this nozzle, and a supply path for supplying a liquid to the nozzle (discharge means). In addition to the inkjet recording head, it can be suitably used for a treatment liquid coating device, a spray coating device, and the like. The discharging means is not only the heater but also the diaphragm and the MEMS (Micro Erectronic) that vibrates the diaphragm.
Machine System) and piezo elements, etc.
Various droplet discharging means can be used.

When the present invention is applied to an ink jet recording head as in the illustrated example, it can be applied to various ink jet recording heads other than the thermal ink jet in the illustrated example. For example, JP-A-5-50601
No. 11,207,956, and No. 11-309850, each of which has an ink chamber in which a nozzle is formed, and one wall surface of the ink chamber is a vibrating plate. The present invention can also be suitably used for an inkjet recording head of a system in which a vibration plate is vibrated by a MEMS, a piezo element or the like, and the vibration energy ejects ink from a nozzle and causes the ink to flow into an ink chamber.

Further, the illustrated example is a so-called top shooter type (face ink jet) ink jet recording head which ejects ink in a direction substantially orthogonal to the substrate surface (the liquid supply direction to the nozzle). Is
In addition to this, as disclosed in Japanese Patent Laid-Open No. 11-263014, ink is ejected substantially parallel to the substrate surface.
A side shooter type (edge inkjet) inkjet recording head may be used.

Further, the ink jet recording head according to the present invention is combined with the intermittent conveyance of the image receiving paper and is scanned by the carriage in the direction orthogonal to the nozzle row, and is a small ink jet recording corresponding to a carriage type printer. It may be a head, or may be a so-called line head in which the nozzle array extends corresponding to the entire area of one side of the image receiving paper (or an area exceeding it).

FIG. 1 shows a schematic view of an example of an ink jet recording head according to the present invention. In FIG. 1, (A)
Ejects ink from the inkjet recording head (flying)
It is the figure (plan view) seen from the direction, (B) is the b-
It is a b line sectional view.

Ink jet recording head 10 of the illustrated example
(Hereinafter, referred to as the recording head 10) is silicon (Si)
The substrate 12 is made by using a semiconductor manufacturing technique, photolithography, or the like. Basically, the substrate 12 and an orifice plate 22 having nozzles 20 for ejecting ink droplets are formed. , A partition wall 15 arranged between the two and forming an ink supply path to each nozzle 20.
And is configured. Further, in the illustrated example, there are a large number of nozzles 20 arranged in one direction (a direction perpendicular to the paper surface in FIG. 1B), and two rows of the nozzles 20 (hereinafter referred to as nozzle rows) are provided. By having the rows, the recording density is improved. The present invention is not limited to this, and the nozzle row may be one row, or three rows.
It may have more than one nozzle row. Also,
The color of ink ejected from each nozzle row and its combination are also arbitrary.

The recording head 10 of the illustrated example is mounted by fixing the substrate 12 at a predetermined position of a frame 24 serving as a supporting member. The recording head 10 is attached to the printer by mounting the frame 24 at a predetermined position of a head unit (for example, a so-called cartridge) of an inkjet printer (not shown).

An ink groove 16 for supplying ink to an ink supply path to each nozzle 20 and an ink supply hole 18 for supplying ink to the ink groove 16 are formed on the substrate 12. Further, the frame 24 and the head unit are provided with an ink supply path (ink flow path 26 in the frame 24) for supplying ink from the ink tank mounted in the head unit to the ink supply hole 18 of the substrate 12. It In the illustrated example, the ink groove 16 extends in the nozzle row direction and is on the surface of the substrate 12 (ink ejection side surface).
Formed to dig in. On the other hand, the ink supply hole 1
8 penetrates the Si substrate 12 so as to communicate with the ink groove 16 from the back surface, is arranged in the nozzle row direction, and a plurality of holes 8 are formed at predetermined intervals.

FIG. 2 shows a schematic sectional view in the vicinity of the nozzle.
2A and 2B are similar to FIG. 1, in which FIG. 2A is a plan view and FIG.
[Fig. 6] is a sectional view taken along line bb. In FIG. 2A, the orifice plate 22 is omitted and the nozzle 20 and the air passage 5 described later are shown in order to make the configuration clearer.
0 is shown by a dotted line.

In the recording head 10, a partition wall 15 is formed on the substrate 12 to form an ink supply path from the ink groove 16 to each nozzle 20 (each heater 30). In the illustrated example, the partition wall 15 is formed between the nozzle 20 and a region 15 a that covers the entire surface of the ink groove 16 on the opposite side of the nozzle 20 and a wall that projects from the region 15 a toward the ink groove 16. And a portion 15b. The walls 15b form the individual flow paths 52 for supplying ink to the individual nozzles 20, and the region of the substrate 12 that does not have the walls 15b is a common flow common to all the nozzles 20. It becomes the path 54. That is, the recording head 1 of the illustrated example
In 0, the ink supplied from the ink tank to the ink flow path 26 of the frame 24 flows in the order of ink supply hole 18 → ink groove 16 → common flow path 54 → individual flow path 52 to be supplied to the nozzle 20.

On the substrate 12, each nozzle 20 (individual flow path 5
The heater 30 corresponding to 2) serves as an ink droplet ejection unit.
Is formed, and further, driving L for driving each heater 30 is formed.
SI14 (see FIG. 1) is formed.

A pressure adjusting means 56 is arranged at a position corresponding to the common flow path 54 of the substrate 12. In the illustrated example, the pressure adjusting means 56 uses a piezoelectric element such as a piezo element to pressurize (or even depressurize) the common flow path 54, that is, the ink supply path. As will be described later in detail, in the recording head 10, the pressure in the common flow path 54 is adjusted by the pressure adjusting means 56, thereby making a difference between the pressure on the ink supply side and the pressure on the ejection side with respect to the nozzle 20. The ink in the nozzle 20 is divided at the time of ejection.

In the recording head according to the present invention, the method of adjusting the pressure of the ink (liquid) supply path is not limited to the one using such a piezoelectric element, and means for adjusting the pressure in the (substantially) closed space. Can be used in various ways, and may be, for example, a pump or the like for inflowing / exhausting gas into the common flow path 54. Further, in the illustrated example, the pressure adjusting means 56 of the ink supply path is arranged in the common flow path 54, and all the nozzles 2
Although the pressure is adjusted for 0, the present invention is not limited to this. That is, the pressure adjusting means may be arranged in the ink supply path from the ink tank to the heater (ejection means), and preferably the common flow path 54 to the individual flow path 52.
Is located in. For example, by arranging the pressure adjusting means in each individual flow path 52, the pressure of the ink flow path may be adjusted independently for each nozzle 20, and the pressure adjusting means is provided for each predetermined number of nozzles 20. Good. Since the pressure adjustment is basically common to all the nozzles 20, it is advantageous in terms of cost that the pressure adjusting means 56 is compatible with many nozzles 20.

The orifice plate 22 on which the nozzles 20 for ejecting liquid droplets are formed is laminated on the partition wall 15. In the illustrated example, the orifice plate 22 is the first plate 22a on the substrate 12 side (hereinafter, this is the lower side).
And an upper second plate 22b. The orifice plate 22 is formed with a ventilation path 50 that communicates the nozzle 20 with the ink ejection surface (the surface of the orifice plate 22) and introduces air (gas) into the nozzle 20. In this example, as shown in FIG. 2, a groove is formed in the first plate 22a and the second plate 22b is formed.
By forming a through hole communicating with this groove, a substantially L-shaped air passage 50 is formed. In addition, formation of such a ventilation path 50 may be performed by a known method using photolithography or the like.

The diameter of the ventilation passage 50 is not particularly limited, and a diameter that can secure a sufficient gas passage for dividing the ink described later and can prevent the inflow of the ink is determined by the viscosity of the ink and the nozzle 20. It may be appropriately determined according to the diameter and the like.

In the present invention, the ventilation path 50 and
Nozzles 20 in the air introduction region for ink separation described below
It is preferable that the inner surface is ink-repellent treated. In the illustrated example, as an example, the entire inner surface of the air passage 50, and
The area shown by the dotted line on the inner surface of the nozzle 20 (from slightly above the lower end of the nozzle 20 to the middle of the opening of the air passage 50) is ink-repellent treated. This makes it possible to further stabilize the liquid surface of the ink supplied by the capillary phenomenon and the division of the ink due to the introduction of air.

The area where the ink repellent treatment is performed is not particularly limited, and may be appropriately determined according to the air introduction area for dividing the ink, which will be described later. In addition, it is preferable that at least the end of the air passage 50 on the nozzle 20 side is subjected to ink repellent treatment. Further, it is preferable that the inner surface of the nozzle 20 is subjected to an ink repellent treatment in a ring shape at an intermediate position in the ink ejection direction. Further, when the ink repellent treatment is performed in an intermediate position on the inner surface of the nozzle 20, the upper end is set to a position that covers the opening of the air passage 50, and the lower end is below the lower end of the air passage 50.
More preferably, it is above the lower end of. The method of the ink repellency treatment is not limited, and may be appropriately determined according to the composition of the ink and the like, but the ink repellency is preferably high. Further, it is preferable that the area of the nozzle 20 which has not been subjected to the ink repellent treatment is subjected to the ink affinity treatment.

Further, in the present invention, it is preferable to have a pump for introducing air (gas) into the air passage 50 in order to more surely introduce air into the nozzle 20 for dividing the ink, which will be described later. Further, if necessary, the pump may have a suction function of sucking the air passage 50.
The pump is, for example, as schematically shown by a dotted line in FIG.
A cover for covering the open ends (ends opposite to the nozzles 20) of all the air passages 50 may be provided so as to be common to all the air passages 50, or may be provided independently for each air passage 50. Alternatively, it may be provided every predetermined number of air passages 50. As in the case of the pressure adjusting means 56 described above, the introduction of air to the nozzles 20 at the time of discharge is basically common to all the nozzles 20. Therefore, in terms of cost, the pressure adjusting means is used. It is advantageous that 56 corresponds to many nozzles 20.

Hereinafter, the present invention will be described in more detail by explaining the action of ink ejection in the recording head 10 with reference to the flowchart of FIG. 3 and the schematic diagrams of FIGS. 4 to 6.

Like an ordinary ink jet recording head,
In the recording head 10 as well, ink is supplied to the nozzles 20 by the capillary phenomenon. Here, in the recording head 10 of the illustrated example, since the area indicated by the dotted line on the inner surface of the nozzle 20 is subjected to the ink repellent treatment, the liquid supply of the ink (represented by the halftone dot) by the capillary phenomenon is as shown in FIG. As shown in (4), it stops at the lower end of the ink-repellent treated area.

Next, the pressure adjusting means 56 pressurizes the common flow path 54 to make the pressure (P1) on the ink supply side larger than the pressure (P2) on the ejection side (P1> P2), and FIG. ), The ink is supplied to the upper end of the nozzle 20. Since the air passage 50 is sufficiently thinner than the nozzle 20, basically no ink flows in at the time of this liquid supply, but the ink inflow into the air passage 50 is more preferably prevented. For this purpose, a check valve may be provided at the open end of the air passage 50 on the nozzle 20 side, or the air passage 50 is preferably subjected to ink repellent treatment as described above.

Next, the pressurization of the common flow path 54 by the pressure adjusting means 56 is stopped (that is, the pressure is reduced), or the pressure of the common flow path 54 is reduced by the pressure adjusting means 56, so that the pressure on the ink supply side ( P1) is made smaller than the pressure (P2) on the discharge side (P1 <P2). As a result, the ink in the nozzle 20 returns to the ink flow path. Here, as described above, since the recording head 10 has the air passage 50 and the area shown by the dotted line in the nozzle 20 is subjected to the ink repellent treatment, air enters from the air passage 50,
The ink above the area that has been subjected to the ink repellent treatment is nozzle 20.
Only the ink held in the upper part of the area and subjected to the ink repellent process returns to the ink flow path. As a result, the ink in the nozzle 20 is divided as shown in FIG. Further, at this time, when a pump for supplying air to the ventilation passage 50 is provided, the introduction of air from the pump to the ventilation passage can more reliably divide the ink in the nozzle 20.

When the heater 30 is driven in this state, bubbles A are generated as in a normal thermal ink jet recording head, and the energy of the bubbles ejects ink droplets ("YES" in the determination in the flowchart). Here, in the illustrated example, since the ink is divided within the nozzle 20, as shown in FIG. 4D, only the divided upper ink is ejected as droplets by a so-called air gun. To be done.

As described above, in the ink jet, the size of the ink droplet is basically determined by the size of the nozzle, and in order to miniaturize the droplet, a method of making the nozzle fine is adopted. There is a limit to miniaturization in terms of accuracy. On the other hand, according to the present invention, the nozzle 2
Since the air passage 50 for introducing air (gas) is provided in the nozzle 0, the ink can be divided in the nozzle 20 and only the ink on the upper side (ejection side) can be ejected. As a result, the ink droplets can be miniaturized regardless of the size of the nozzle 20.

When the ejection of the ink is completed, the air bubbles A are cooled by cooling, as in a normal (inkjet) recording head.
Contracts and the ink surface becomes lower than the nozzle, but as described above, so-called refill is performed by the capillary phenomenon, and the state shown in FIG. 4 (A) is obtained. After that, in order to perform the next ink ejection, similarly, the ink is filled in the nozzle 20 by P1> P2 by the driving of the pressure adjusting unit 56, and the nozzle 2 by P1 <P2 by the same driving stop
The ink in 0 is divided, the ink droplets are discharged by driving the heater 30, and the ink droplets are repeatedly discharged according to the image to be recorded.

In the recording head 50, the ink is not necessarily ejected from all the nozzles 20 in the image recording, and naturally, depending on the recording image, some of the ink is naturally ejected once in the recording head 10. In the ejection operation, there are also nozzles 20 that do not eject ink. This nozzle 20 can be used even after another nozzle ejects ink.
It is held in the state shown in FIG. 4C (“NO” in the determination of the flowchart shown in FIG. 3).

This state is shown in FIG.
(Same state as (C)) In the illustrated example, the pressure adjusting means 5
Since No. 6 is common to all the nozzles 20, P1> P by driving the pressure adjusting unit 56 after the above-described ink ejection.
In the state of 2, the ink is supplied to the nozzles that have not ejected the ink. Here, in the nozzles 20 that did not eject ink, the air that has divided the ink in the nozzles 20 is discharged from the ventilation passages 50 and supplied by this liquid supply, as shown in FIG. 5B. Only the ink rises in the nozzle, and finally, as shown in FIG. 5 (C), the inside of the nozzle 20 is filled with the ink (the same state as FIG. 4 (B)).

As described above, when the pump for introducing air into the ventilation passage 50 has a suction function, the ventilation passage 50 is sucked at this time to discharge the air in the nozzle 20 by the liquid supply. You may assist. In addition, as described above, the nozzle 2
By setting the upper end of the ink repellent treatment on the inner surface of 0 to a position (in the illustrated example, the middle of the opening) of the ventilation passage 50,
This liquid supply is preferable because the air in the nozzle 20 can be exhausted more reliably.

Here, the liquid supply by P1> P2 is continued even after the nozzles 20 which have not discharged are filled with ink. However, the nozzle 20 filled with ink
Then, due to the surface tension at the upper end of the nozzle 20,
Since ink does not flow in any more, ink leakage can be prevented. Further, in order to prevent the ink leakage more reliably, it is also preferable that the inner surface of the upper end portion of the nozzle 20 is subjected to the ink repellent treatment. In addition, the pressure adjusting means is used for each nozzle 2
In the case of having the value corresponding to 0, it goes without saying that the liquid supply amount may be controlled for each nozzle.

In the recording head 10, if a small amount of ink is present in the nozzle 20 and left for a long time, the ink may dry and nozzle clogging may occur.
In order to prevent this, during standing or standby, ink is ejected from all the nozzles 20 once to obtain the state shown in FIG. 4A, or the pressure adjusting means 56 is driven to set P1> P.
The state 2 is preferable, and the state shown in FIG. 4B is preferable.

FIG. 6 shows an example of the ink jet printer of the present invention using the recording head 10 of the present invention. In addition, in FIG. 6, (A) is a conceptual view (side view) showing the configuration of the inkjet printer as viewed from the nozzle row direction, and (B) is a concept when the inkjet printer is viewed from an oblique direction. It is a figure (perspective view). The inkjet printer 80 (hereinafter referred to as the printer 80) shown in FIG. 6 includes a line head having a nozzle row extending in one direction of the corresponding image receiving paper P, and the recording head 1.
It is used as 0. This printer 80 is basically the same as the printer 80 except that the recording head 10 according to the present invention is used.
It is a known inkjet printer.

The printer 80 shown in FIG. 6 has a recording section 82 using the recording head 10 of the present invention, a paper feeding section 84, a preheating section 86, and a discharging section 88 (omitted in FIG. 6B). Composed.

The paper feeding section 84 includes a pair of conveyance rollers 92 and 9.
4 and the guides 96 and 98, the image receiving paper P is conveyed upward from the lateral direction by the paper feeding section 84 and supplied to the preheating section 86.

The preheating section 86 includes a conveyor 100 including three rollers and an endless belt, a pressure roller 102 that is pressed against the endless belt from outside the conveyor 100, and a pressure roller 1 from inside the conveyor 100.
Heater 104 pressed by 02 (endless belt)
And an exhaust fan 106 for exhausting the inside of the preheat portion 86 (inside the housing 86a). The preheating unit 86 is for promoting the drying of the ink by heating the image receiving paper P prior to the recording of the image by the ink jet, and the image receiving paper P conveyed from the paper feeding unit 84.
While being nipped and conveyed by the conveyor 100 and the pressure bonding roller 102, it is heated by the heater 104 and conveyed to the recording unit 82.

The recording section 82 is the recording head 1 of the present invention.
0 is mounted on the head unit 110, and the recording / transporting unit 108 is configured. Also, the head unit 1
10 includes ink tanks 112 (112Y, 112C,
112M, and 112B) are mounted. The recording / transporting unit 108 includes a conveyor 120 including rollers 114a and 114b, a suction roller 116, and a porous endless belt 118, and a nip roller 122 (FIG. 6) pressed by the porous endless belt 118 (roller 114a).
(Omitted in (B)) and a suction box 124 arranged in the conveyor 120.

The recording head 10 is mounted on the lower end of the head unit 110 (the image receiving paper P side on the lower side in the drawing) with the nozzle 20 facing the suction roller 116. In addition, the recording conveyance means 1
The image receiving paper 08 is continuously conveyed at a predetermined speed in a direction orthogonal to the nozzle row direction. Therefore, the preheating unit 80
The image receiving paper P supplied from is scanned over the entire surface by the nozzle row of the recording head 10 which is a line head, and an image is recorded. Further, the conveyor 120 is the perforated endless belt 1
18 and further has a suction roller 116 and a suction box 124. Therefore, the image receiving paper P is conveyed while being attracted to the perforated endless belt 118, and an image is recorded on the recording head 10 while being properly maintained at a predetermined position.

The image receiving paper P on which the image is recorded is discharged from the discharge section 88.
To the conveying roller pair 126 and the discharging roller 12
The sheet is conveyed by 8 and discharged to, for example, a discharge tray (not shown).

The ink jet printer of the present invention is not limited to the above example, and various known ink jet printers can be used. For example, it may be a carriage type printer that intermittently conveys the image receiving paper and scans a recording head (head unit) with a carriage, and has a feeder or the like that automatically supplies the image receiving paper. May be.

Although the droplet discharge device and the ink jet printer of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and various improvements and improvements are possible within the scope of the present invention. Of course, changes may be made. For example, the above example is a thermal ink jet in which ink droplets are ejected by a heater, but in the present invention, a piezoelectric element such as a piezo element may be used as the droplet ejection means, as described above. In that case, the droplet discharge means may also serve as the pressure adjusting means of the ink supply path. Further, in the example shown in FIG. 5, the nozzles that have not been ejected are also supplied with liquid by pressure adjustment. For example, when pressure adjusting means is provided for each nozzle, ink division is performed. In this state, the state of FIG. 4C may be maintained until the next ejection.

[0050]

As described above in detail, the droplet discharge device of the present invention can discharge minute droplets regardless of the size of the nozzle, and can be used in, for example, an inkjet recording head. Due to the short fixing time of ink,
A recording head capable of high-speed recording can be realized. Further, the ink jet printer of the present invention using such a droplet discharge device of the present invention is a printer capable of high-speed recording using minute droplets.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of an inkjet recording head according to the present invention, in which (A) is a plan view and (B) is (b) of (A).
It is a -b line sectional view.

2 is a partially enlarged view of FIG. 1, (A) is a plan view,
(B) is a bb line sectional view of (A).

FIG. 3 is a flowchart showing a droplet discharge action of the inkjet recording head according to the present invention.

FIG. 4A to FIG. 4D are conceptual diagrams showing a droplet discharge action of the inkjet recording head according to the present invention.

5A to 5C are conceptual diagrams showing the operation of the inkjet recording head according to the present invention.

6A and 6B are conceptual views of an example of an inkjet printer of the present invention, in which FIG. 6A is a side view and FIG. 6B is a perspective view.

[Explanation of symbols]

10 (inkjet) recording head 12 Si substrate 14 Drive LSI 16 ink grooves 18 Ink supply hole 20 nozzles 22 Orifice plate 24 frames 30 heater 50 air passage 52 individual flow paths 54 common channel 80 (inkjet) printer 82 Recording section 84 Supply Department 86 Preheat part 88 Ejector 96,98 guide 92, 94, 126 Transport roller pairs 100,120 conveyor 102 Crimping roller 104 heater 106 exhaust fan 108 recording and conveying means 110 head unit 112 ink tank 114a, 114b rollers 116 suction roller 118 Perforated endless belt 122 nip roller 124 suction box 128 discharge roller pair

Claims (5)

[Claims] 1. A plurality of nozzles, a discharge means for discharging a droplet from the nozzle, a supply path for supplying a liquid to the nozzle, a pressure adjusting means in the supply path, and a gas introduction into the nozzle. A droplet discharge device, comprising: 2. The liquid is supplied to a predetermined height of the nozzle by pressurizing the inside of the supply passage by the pressure adjusting means,
Next, by depressurizing the inside of the supply path by the pressure supply means, gas is introduced into the nozzle from the ventilation path, and the liquid in the nozzle is divided into the discharge port side and the supply path side by this gas, and this state 2. The liquid droplet ejection apparatus according to claim 1, wherein the liquid on the ejection port side in the nozzle is ejected as liquid droplets by driving the ejection means. 3. The liquid repellent process for the discharged liquid, wherein at least the end portion on the nozzle side of the inner surface of the air passage and the inner surface of the nozzle including at least a part of the opening of the air passage are annularly subjected to liquid repellent treatment with respect to the discharged liquid. The droplet discharge device according to item 1. 4. The droplet discharge device according to claim 1, further comprising a pump for introducing gas into the nozzle from the ventilation passage. 5. An inkjet printer using the droplet discharge device according to any one of claims 1 to 4 as an inkjet recording head.