JPH0470355A - Ink head recovery device - Google Patents

Abstract

PURPOSE:To remove foreign particle and bubble in an ink flow path in an efficient manner to minimize the wasteful use of ink by a method wherein after an inner pressure in each ink flow path is raised by a closing plate as a closing means, the ink in the ink flow path is jetted out of each nozzle. CONSTITUTION:When a plurality of ink flow paths 3 in a nozzle plate 2 are clogged with foreign particle or a bubble is produced therein, a capping member 19 comes close to an ink head 1, and the peripheries of respective nozzles 4 are covered with a capping main body 20. In this state, a closing plate 25 is brought into close contact with an end face 24 of the nozzle plate 2. A high- pressure air is supplied to a buffer ink tank 11 through a supply tube 13 by driving a motor 18. The pressure of ink in the respective ink flow paths 3, an ink tank 9, and the buffer ink tank 11 is gradually increased. After a predetermined time elapses from the start of driving the motor 18, the closing plate 25 is separated from the end face 24 of the nozzle plate 2. Then, the respective nozzles 4 are externally opened, and ink flows in the ink flow paths 3 to be jetted out of the nozzles 4 at a high speed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is used in printers that print by jetting ink, such as inkjet printers and bubble jet printers, and is used to prevent clogging in the ink flow path of an ink head. The present invention relates to an ink head recovery device that removes foreign objects and air bubbles.

[Conventional technology]

The above-mentioned inkjet printer has an ink flow path whose tip is formed as a nozzle in an ink head, and at least part of the outer peripheral wall of this ink flow path is formed of a flexible material. A piezoelectric element is provided adjacent to the ink passage, and by energizing the piezoelectric element at a predetermined printing timing, the cross-sectional area of the ink passage is reduced, and the ink in the ink passage is ejected from the nozzle and lands on the paper. , it is designed to print.

In addition, the above-mentioned bubble jet printer has an ink flow path whose tip is formed as a nozzle in the ink head, and a thermal head adjacent to the ink flow path. By energizing the head, air bubbles are generated in the ink flow path, and a volume of ink corresponding to the air bubbles is ejected from the nozzle and landed on the paper, thereby performing printing.

By the way, in printers that print by ejecting ink, such as the aforementioned inkjet printers and bubble jet printers, if the ink dries and becomes clogged in the ink flow path of the ink head, the nozzles become clogged, and the nozzles become clogged. There is a risk that the ink will not be ejected properly from the nozzle, and if air bubbles are generated in the ink flow path, the specified internal pressure will not be obtained during ink ejection, so there is a risk that the ink will not be ejected properly from the nozzle. be.

For this reason, conventional techniques have been used to inject high-pressure ink into the ink flow path by injecting high-pressure air into an ink tank that communicates with the ink flow path. An ink head recovery device is used which is equipped with an air jet means for removing the ink.

By the way, in a conventional ink head recovery device, when high-pressure air is injected into an ink tank by an air ejecting means, a negative pressure is created near the nozzle at the tip of an ink flow path, and the high-pressure ink flows into the ink flow path. Alternatively, the ink in the ink tank is first pressurized with high-pressure air, and then the high-pressure ink is introduced into the ink flow path.

[Problem to be solved by the invention]

However, in the conventional ink head recovery device described above, the ink flow speed in the ink flow path could not be made that high, so foreign objects and bubbles in the ink flow path could not be efficiently removed, resulting in a large amount of was wasting ink.

The present invention overcomes the problems of the conventional devices described above, and provides an ink head recovery device that efficiently removes foreign objects and air bubbles in the ink flow path and limits wasteful ink consumption to a small amount. The purpose is to

[Means to solve the problem]

In order to achieve the above-mentioned object, an ink head recovery device according to the present invention includes an ink tank of an ink head, which has an ink flow path whose tip is a nozzle and an ink tank communicating with the ink flow path. The ink head recovery device is equipped with a high-pressure air supply means for supplying high-pressure air to the ink head, and is characterized in that a closing means that can freely open and close the nozzle-side end of the ink flow path is movably disposed.

[For production]

According to the present invention having the above-described configuration, first, in a state where the nozzle side end of the ink flow path is closed by the closing means, high pressure air is injected into the ink tank by the high pressure air supply means to drain the inside of the ink flow path. Increase ink pressure. Then, when the pressure of this ink reaches a set pressure or after a set time has elapsed, the blockage of the nozzle side end of the ink flow path by the blockage means is released by moving the blockage means. Then, high-pressure ink is ejected from the nozzle, creating a high-speed ink flow within the ink flow path. Therefore, foreign matter and air bubbles in the ink flow path can be reliably removed by instantaneous ink jetting from the nozzle, and wasteful ink consumption can be kept to a small amount.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

FIGS. 1 and 2 show an ink head recovery device according to the present invention in different states.

1 and 2, the ink head 1 has a flat rectangular parallelepiped-shaped nozzle plate 2, and each nozzle plate 2 is formed by laminating a glass substrate and a diaphragm to each other. There is. A plurality of ink channels 3, 3, each having a nozzle 4 at its tip, are formed by etching on the inner surface of the substrate within the thickness. Further, on the upstream side of each ink flow path 3, a narrow chamber 5 is formed to prevent backflow of ink when the ink is ejected from the nozzle 4.

Ink flow path 3 between each cap body 4 and the constriction chamber 5
An electrode (not shown) consisting of a common electrode and a plurality of individual electrodes is stretched on the surface of the diaphragm at a portion corresponding to the ink flow. A plurality of piezoelectric elements (not shown) corresponding to the channels 3 are interposed.

Then, by selectively energizing each piezoelectric element in accordance with the print information, the diaphragm at the part corresponding to a specific ink flow path 3 is vibrated, and the ink in that ink flow path 3 is removed from the nozzle 4. Can be injected.

A tank member 6 is connected to the base end side of the nozzle plate 2. This tank member 6 has a rectangular parallelepiped shape as a whole, and a cylindrical projection 8 is integrally provided at approximately the center of one end surface 7A of this tank member 6. Further, an ink tank 9 is formed in the tank member 6, and reaches the other end surface 7B from the protrusion 8 of the end surface 7A, and this ink tank 9 has a small diameter on the end surface 7A side, and On the side, it is expanded in the vertical direction in the middle so as to correspond to about 3/4 of the range in the vertical direction of the end surface 7B. Then, the end face 7 of this tank member 6
On the B side, the base end side of the nozzle plate 2 is fitted so that each ink flow path 3 communicates with the ink tank 9, and an O-ring 10 is attached to the outer periphery of the nozzle plate 2 in the tank member 6.
are fitted to prevent ink from leaking from the outer periphery of the nozzle plate 2.

A connector 12 of a buffer ink tank 11 for supplying ink to the ink tank 9 of the tank member 6 is connected to the protrusion 8 of the tank member 6, and the buffer ink tank 11 is connected to an ink supply source (not shown). Ink is supplied by a pump or the like. Further, a supply pipe 13 for introducing high pressure air into the buffer ink tank 11 is connected to the upper end of the buffer ink tank 11, and an upstream end of the supply pipe 13 is connected to a pressure air supply means. Cylinder device 1 as an example of
4 are arranged. This cylinder assembly w14 has a piston 16 that can slide inside the cylinder 15, and is provided with an injection member made of this flexible material. A motor 18 for moving 16 is connected.

On the other hand, a cap member 19 is provided on the front surface of the ink head 1 to cover each nozzle 4 of the ink head 1 and prevent the ink inside the nozzle 4 from drying when not in use. The cap member 19 has a rubber cap body 20 facing each nozzle plate 2 . This cap body 2
0 is formed into a deep dish shape by an end 121 and a peripheral wall 22 provided around the outer periphery of the end wall 21. It is in pressure contact with the end surface 23 of the head 1 so as to cover the outer periphery of each nozzle 4 and hang therefrom.

Inside the cap body 20, there is an end surface 2 of the nozzle plate 2.
A closing plate 25 is disposed which is tightly joined to the nozzle 4 and can completely close the front of each nozzle 4 in a liquid-tight manner. A driving means 26 such as a cylinder device mounted on the cap member 19 and located outside the cap main body 20 is connected to the closing plate 25, and the closing plate 25 is driven by the driving means 26. It is designed to be able to move toward and away from the end surface 24 of the nozzle plate 2. Further, an ink discharge pipe 27 that communicates with the inside of the cap body 20 is connected to the lower end of the cap body 20, and a suction pump (not shown) is interposed in this ink discharge pipe 27.

Next, the operation of this embodiment having the above-described configuration will be explained.

If any of the plurality of ink flow paths 3 formed in the nozzle plate 2 is clogged with foreign matter or air bubbles are generated, the cap member 19 is moved close to the ink head 1 and the cap body 20 is used to clean each ink flow path 3. While covering the outer periphery of the nozzle 4, the drive means 26 causes the closing plate 25 to tightly join the end face 24 of the nozzle plate 2, as shown in FIG.

Then, when the motor 18 is driven to supply high-pressure air into the buffer ink tank 11 through the supply pipe 13, since the tip of each nozzle 4 is closed by the closing plate 25,
By supplying high-pressure air into the buffer ink tank 11, the pressure of the ink in each ink flow path 3, ink tank 9, and buffer ink tank 11 gradually increases. Therefore, when a set time has elapsed from the start of driving the motor 18, the driving means 26 is driven to separate the closing plate 25 from the end surface 24 of the nozzle plate 2, as shown in FIG. Then, since each nozzle 4 is opened to the outside, high-pressure ink flows through each nozzle 4 at high speed.
As a result, the ink flows inside each ink flow path 3 at high speed. Therefore, foreign matter and air bubbles in the ink flow path 3 are instantly discharged to the outside from the nozzle 4. Therefore, after the closing plate 25 is separated from the vibrator 23 of the nozzle plate 2, the cylinder assembly is immediately removed. The load on the buffer ink tank 11 caused by the buffer ink tank 14 can be relieved. Note that the closing plate 25 is replaced by the nozzle plate 2.
The ink ejected from each nozzle 4 in the state separated from the end surface 24 of the cap body 20 accumulates at the bottom of the cap body 20, but since the ink discharge pipe 27 is connected here,
The ink inside the cap body 20 can be removed by driving a suction pump (not shown) installed in the ink discharge pipe 27.

According to this embodiment, the ink in the ink channels 3 is ejected from each nozzle 4 after the internal pressure in each ink channel 3 is increased by the blockage plate 25. Certain foreign matter or bubbles can be injected and discharged from the nozzle 4 to the outside. Therefore, wasteful consumption of ink can be kept to a small amount.

By the way, in the above-described embodiment, when the air pressure is applied to the buffer ink tank 11 by the motor 18 for a set time while the closing plate 25 is closely connected to the end surface 24 of the nozzle plate 2, the driving means 26 closes the closing plate 25.
Although the explanation has been made in such a manner that the closing plate 25 is separated from the end surface 24 of the nozzle plate 2, it is also possible to configure the closing plate 25 to be separated from the end surface 24 of the nozzle plate 2 when the pressure of the ink in the ink flow path 3 reaches a set pressure. It is possible.

In this case, a pressure detection means is installed in one of the ink channels 3, and when the pressure in the ink channel 3 reaches a predetermined pressure, the closing plate 25 is separated from the vibrator 23 of the nozzle plate 2. Good too.

Note that the present invention is not limited to the embodiments described above, and various changes can be made as necessary.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to efficiently remove foreign objects and air bubbles in the ink flow path, thereby achieving the practical effect of keeping wasteful ink consumption to a small amount.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views showing an embodiment of an ink head recovery device according to the present invention. DESCRIPTION OF SYMBOLS 1... Ink head, 2... Nozzle plate, 3... Ink flow, 4... Nozzle, 6... Tank member, 9...
・Ink tank, 11...Buffer ink tank, 1
4...Cylinder device, 18...Motor, 19...
Cap member, 20... Cap body, 25... Closure plate, 26... Driving means, 27... Ink discharge pipe. Procedural amendment layer August 3, 1990 1 Display of case 1990 Patent Application No. 175108 2 Name of invention Ink head recovery device 3 Person making amendment Relationship with case Patent applicant (AO9) Alps Electric Co., Ltd. 8 Contents of the amendment 1) The claims in the specification are corrected as follows. An ink head that has an ink flow path with a nozzle at its tip and an ink tank that communicates with the ink flow path, and that is equipped with pressure supply means for creating high pressure in the ink tank. The ink head recovery device is characterized in that the nozzle side end of the ink flow path is movably disposed to close the nozzle side end so as to be openable and closable.J2) Page 5, line 2 of the specification. [High-pressure air that supplies high-pressure air into the ink tank] is corrected to "pressure J to make the inside of the ink tank high. 3) "Cap body 4" in line 6 @ line 16 of the specification is replaced with "nozzle 4. ” he corrected. 4) On page 8 of the specification, lines 4 to 14, [Protrusions 8 of the tank member 6 are... ” is corrected as follows. [The connector 12 of an ink cartridge 11 for supplying ink to the ink tank 9 of the tank member 6 is connected to the protrusion 8 of the tank member 6. Further, a supply pipe 13 for introducing high-pressure air into the ink cartridge 11 is connected to the upper end of the ink cartridge 11, and an upstream end of the supply pipe 13 is connected to a supply pipe 13 as an example of pressure supply means. A cylinder device f14 is provided. 5) "To nozzle plate 2" on page 10, line 14 of the specification
is corrected to "of nozzle plate 2." 6) "Buffer ink tank 11" in lines 16, 18, and 20 of page 10 of the specification is corrected to "ink cartridge 11J." 7) "Vibe 23" in line 12 of page 11 of the specification. is corrected to ``1-side 24''. 8) On page 11, lines 13 and 14 of the specification, [buffer ink tank 11J is corrected to read "ink cartridge 11." 9) Change "buffer ink tank 11" from line 11 to line 12 on page 12 of the specification to "ink cartridge 11".
I am corrected. 10) Specification page 12, line 20 to page 13, line 1
Correct the line ``Pipe 23'' to read ``One end surface 24''. 11) Ming IA? ! , '1413 N In line 15, ``Baratsuno Ink Tank'' is corrected to ``Ink Car 1~Rituji''. that's all

Claims (1)

[Claims] An ink head recovery device comprising a high-pressure air supply means for supplying high-pressure air to an ink tank of an ink head, the ink head having an ink flow path whose tip is a nozzle and an ink tank communicating with the ink flow path formed inside. An ink head recovery device, characterized in that a closing means is movably disposed to open and close the nozzle side end of the ink flow path.