JPS5816854A - Nozzle head for ink jet - Google Patents

Abstract

PURPOSE:To prevent nozzles from getting clogged and to easily make cleaning even in case of getting clogged by a nozzle head wherein a cover is openably provided at the side of the nozzle head body which has at the same side a plurality of grooves used for jetting ink. CONSTITUTION:Grooves 8a-8e are formed at the side of a nozzle head body 7, so that it functions as a nozzle for jetting ink. On the same side where those grooves 8a-8e are formed in the nozzle head body 7, a plate-like cover 10 is provided a part of which is mounted to the nozzle head body 7 by means of a hinge 9. When jetting ink from the nozzle, ink retained in the grooves 8a-8e can be removed by opening the cover 10 and returning the retained ink to a liquid reservoir 11. Also, even when ink is solidified and the nozzle got clogged because of long term stoppage, the nozzle can be easily cleaned by opening the cover 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet nozzle head, and particularly to an inkjet nozzle head having a plurality of nozzle openings.

Conventional printing devices and information output terminals record various types of output information by colliding a wire head, 4 characters, etc. with recording paper via an ink ribbon, but they make a lot of noise during recording. (This used to cause noise pollution when used in relatively quiet offices, etc.) In recent years, as an output device to solve this problem, liquid ink is ejected by some means and onto recording paper. So-called inkjet output devices that record various types of output information have been developed and are beginning to be used generally.The inkjet format can be roughly divided into four types: charge control method, ink on demand method, electric field control method, and ink mist method. The charging control method uses a vibrator to constantly eject ink into droplets, charge the ejected ink, and then deflect the charged ink droplets using an electric field. The ink-on-demand method uses a piezoelectric element such as a piezoelectric element to apply pressure to an ink reservoir according to the output information, causing the ink to fly out and record on the recording paper. In the electric field control method, a potential is applied between the nozzle opening and the recording paper according to the output information, and ink is drawn out from the nozzle opening by electrostatic attraction and attached to the recording paper to perform recording. The ink mist method uses a vibrator to atomize the ink held in the ink reservoir, selectively ionizes the atomized ink using electrical discharge according to the output information, and then uses electrostatic attraction to ionize the ionized ink. The nozzle head of the present invention uses an electric field control method.

Conventionally, an electric field control type nozzle head has a single nozzle opening, and therefore, a method has been used in which recording is performed on the entire recording paper by scanning the nozzle head in the line direction. However, this method has the problem that recording is performed at a relatively low speed because the nozzle head is mechanically scanned. In order to solve this problem, a nozzle head with multiple nozzle openings in the line direction is used to selectively select multiple nozzle openings according to output information without mechanically scanning the nozzle head. A method has been proposed in which information for one line is recorded almost simultaneously by applying a potential. FIG. 1 shows a schematic diagram of an inkjet recording apparatus equipped with such an inkjet nozzle head having a plurality of nozzle openings.

The inkjet recording apparatus is configured such that the recording paper 3 is positioned between a nozzle head 2 having a large number of nozzle openings and a needle-like electrode 5 having electrodes corresponding to each nozzle opening. The liquid ink is pressurized by the pressure pump 1 or static ink pressure, thereby forming a hemispherical meniscus at the nozzle opening.

By applying a voltage corresponding to the output information to the voltage application terminal 4 and the needle electrode 5, that is, by selectively applying a voltage to each electrode of the needle electrode 5 in accordance with the output information, each nozzle is The ink meniscus formed in the opening selectively flies due to electrostatic attraction and adheres to the recording paper 3, thereby recording output information. Furthermore, the recording paper 3 is transported by the feed roller 6 and the output information of the next line is recorded, thereby recording the output information over the entire recording paper 3.

By using a nozzle head with such a large number of nozzle openings, information for each line can be recorded almost simultaneously without having to mechanically scan the nozzle head itself in the line direction, so various types of information can be recorded at high speed. Output information can be recorded. However, as a result of intensive research by the present inventors on the nozzle head having a plurality of nozzle openings as described above, it was found that the nozzle head has the following serious problems. In other words, there is no problem when the ink is constantly ejected from the nozzle opening 1, but if the inkjet recording device is not used for a certain period of time, the ink does not eject from the nozzle opening (and the moisture in the ink in the nozzle area). Alternatively, it was found that when the solvent evaporates, the ink solidifies, causing a problem of clogging of the nozzle.Furthermore, once this clogging occurs, it is extremely troublesome to clear this clogging. The problem has conventionally occurred even in nozzle heads with a single nozzle opening, but in nozzle heads with multiple nozzle openings, the frequency of nozzle clogging is proportional to the number of nozzles, and it is even more difficult to prevent clogging. Since cleaning must be performed for each nozzle to eliminate the problem, the problem is even more serious than in the case of a nozzle head with a single nozzle.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an inkjet nozzle head having a plurality of nozzle openings that do not cause clogging or can easily clear the clogging even if clogging occurs.

The inkjet nozzle head of the present invention includes a nozzle head body having a side surface provided with a plurality of grooves for ejecting ink, and a plate-shaped lid body provided in close contact with the side surface of the nozzle head body. The lid body is provided on the side surface of the nozzle head body so as to be openable and closable.

Therefore, by leaving the lid open when the inkjet recording device is not in use so that ink can be removed from the nozzle, it is possible to prevent clogging caused by ink solidification in the nozzle. This has the advantage that even if the nozzle becomes clogged, it can be easily cleaned by opening the lid.

The present invention will be described in detail below with reference to the drawings. FIG. 2 is a perspective view 1'hx showing an embodiment of the inkjet nozzle head of the present invention.

A groove 8a18b is formed on the side surface of the nozzle head body 7.

8C18d and 8e are formed, each functioning as a nozzle for ejecting ink.

Groove 8 in nozzle head body 7. a, 8 b, 8 c1
A plate-shaped lid body 10 is partially attached to the nozzle head body 7 by a hinge 9 on the side where 8d and 8e are formed (corresponding to the upper part when attached to an inkjet recording apparatus).
is provided. When using the inkjet recording device, that is, when ink is ejected from the nozzles, the lid 10 is brought into close contact with the nozzle head body 7, and when the inkjet recording device is not used, the lid 10 is opened and the nozzles, ie, the grooves 8a, 8, are opened.
b, 8c.

The ink held in 8d and 8e can be removed by returning it to the reservoir 11 or the like. Further, even if the nozzle becomes clogged due to solidification of ink caused by not allowing ink to fly from the nozzle for a long time, the nozzle can be easily cleaned by opening the lid 10. As means for bringing the lid 10 into close contact with the nozzle head body 7, there may be used methods such as using the own weight of the lid 10 by forming the lid 10 from a material with a large specific gravity, or using conventionally known clamping means. .

In the above description, the lid 10 is provided at the top of the nozzle head body 7, but it is also possible to completely reverse this positional relationship and provide the lid 10 at the bottom of the nozzle head body 7. good. In this case, a clamp means can be used as a means for bringing the lid body 10 into close contact with each other.

Further, the lid 10 and the nozzle head main body 7 can be completely connected without engaging the lid 10 with the nozzle head main body 7 by the hinge 9.
may be made separable.

, FIG. 3 is a perspective view of a case where a layer of a hydrophilic substance is provided in the grooves of the inkjet nozzle head of the present invention. A layer 12 of sexual material is provided. In a nozzle head with a large number of nozzles, it is difficult to form a uniform meniscus at each nozzle opening.
By providing the hydrophilic material layer 12 in this manner, ink can be smoothly transferred through the nozzles, and a uniform meniscus can be formed at each nozzle opening.

FIG. 4 is a perspective view showing the inkjet nozzle head of the present invention in which the lid has a cushioning material on the side in close contact with the nozzle head.

In the inkjet ink nozzle of the present invention, the nozzle head main body 7, the lid 1O, and the force 1 are provided on the side body, and therefore, as described above, the clamping means or the lid 1
Although the nozzle head main body 7 and the lid body 10 are brought into close contact with each other by their own weight of 0, the nozzle head main body 7 and the lid body 1
It was found that it was quite difficult to apply a uniform force between the two parts, and that some parts could not be brought into close contact with each other.

Also, while the lid body 10 is repeatedly opened and closed, the nozzle head body 7 may be scratched or the grooves 8a, 8b, 8c may be damaged.
, 8d, 8e may be destroyed. As a means to solve this problem, it has been found that it is effective to provide the cushioning material 13 on the side of the lid 10 that comes into close contact with the nozzle head body 7, as shown in the drawing.

FIG. 5 is a perspective view showing a case where the grooves provided in the nozzle head body have a staggered arrangement.

Grooves 8a forming nozzles on both sides of the nozzle head body 7;
8b, 8c, 8d, 8e, 8a'.

81) 1, 8 c', 8 d', 8 e' are provided, and further grooves 8a, 8b, 8C provided on one side,
Grooves 8a+ and 8bl with grooves 8d and 8e provided on the other side
, gcl, 8dl, and Bel, forming a so-called staggered arrangement. A nozzle head configured in this manner has higher resolution than a nozzle head that has grooves formed on one side.

Note that two lid bodies 10 and 101 are used so that both sides of the nozzle head body 7 are brought into close contact with each other.

FIG. 6 is a perspective view I11'b showing a state in which the nozzle head main body is installed on the nozzle head support by using magnetic force.

By installing the nozzle head main body 7 on the nozzle head support 14 using magnetic force as shown in the figure, the nozzle head main body 7 can be easily attached to and detached from the nozzle head support 14. In this way, the nozzle head body 7 can be easily attached and detached from the grooves 8a, 8b1 to 8c of the nozzle head body 7.

When the nozzle head 8d becomes unusable due to clogging, etc., it can be easily replaced with a new nozzle head main body 7. Note that using magnetic force means that the side of the head support 14 that contacts the head main body 7 By making at least a part of the head body 7 a magnet, and by making the part of the head body 10 corresponding to the magnet a magnetic material (a material that is attracted to the magnet), or conversely, by providing a magnet in the head body 7 and attaching it to the head support 14. This means using magnetic force generated by providing a magnetic material or the like.

FIG. 7 is a schematic diagram showing an embodiment in which the lid body is automatically opened and closed.

As mentioned above, when the ink is not flying, it is effective to remove ink from the nozzle groove by placing the lid 10 in a position away from the nozzle head body, that is, in the open position, but it is also effective to prevent clogging. By synchronizing the opening/closing operation of the lid with the power on/off operation of the inkjet recording apparatus, nozzle clogging can be prevented with an even simpler operation. As shown in FIG. 7, a coil-shaped spring 15 is installed between the lid 10 and the nozzle head body 7, and urges the lid to open. Further, a vacuum pump 16 is provided on the side of the nozzle head body 7, and by sucking air through the suction hole 17, it becomes possible to bring the lid body 10 into close contact with the nozzle head body 7.

Therefore, if the vacuum pump 16 is operated in synchronization with the power-on operation of the inkjet recording device, the lid body 10 can be brought into close contact with the head body 7 by the suction force, and also in synchronization with the power-off operation of the inkjet recording device. When the vacuum pump 16 is stopped, the lid body 10 can be positioned away from the nozzle head body (open position) by being biased by the spring 15.

FIG. 8 is a schematic diagram showing another embodiment in which the lid body is automatically opened and closed.

In this embodiment, a portion of the lid 10 is connected by a coupling body 18 to a piston 20 that can be moved in and out in the direction shown by the arrow 19. Therefore, the piston 20 is operated to bring the lid 10 into close contact with the nozzle head body in synchronization with the power-on operation of the inkjet recording apparatus, and the lid 10 is moved away from the nozzle head body in synchronization with the power-off operation. It becomes possible to operate the piston 20 in this manner. In order to actually realize such an operation, it is sufficient to delay the power-off operation by a short period of t7 before the actual power-off is performed. Note that the method for automatically opening and closing the lid body is not limited to this embodiment, and various modifications can be made within the scope of the claims.

As explained in detail above, the inkjet nozzle head of the present invention consists of a nozzle head body and a lid body, and the nozzle head is placed in the closed position where the lid body is in close contact with the side of the nozzle head body where the groove for the nozzle is provided. Since the open position can be moved away from the main body, clogging of the nozzle can be prevented, and furthermore, if clogging occurs, it can be easily cleaned.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an inkjet recording apparatus equipped with an inkjet nozzle head having a plurality of nozzle openings, and FIG. 2 is a perspective view showing an embodiment of the inkjet nozzle head of the present invention. , FIG. 3 is a perspective view of the inkjet nozzle head of the present invention in which a hydrophilic substance layer is provided in the groove, and FIG. 4 is a perspective view of the inkjet nozzle head of the present invention in which the lid body is attached to the nozzle head. FIG. 5 is a perspective view showing a case where a cushioning material is provided on the side that comes into close contact with the nozzle head body; FIG. 5 is a perspective view showing a case where grooves provided in the nozzle head body have a staggered arrangement; FIG. FIG. 7 is a perspective view showing a state in which the main body is installed on a nozzle head support using magnetic force, and FIG. 7 is a schematic diagram showing an embodiment in which the lid body is automatically opened and closed. FIG. 8 is a schematic diagram showing another embodiment in which the opening and closing operations of the lid body are automatically performed. 2...Nozzle head 5...
...Acicular electrode 7...Nozzle head main body 8a, 8b, 8c, 8d, 8e18a: 8b
', 8 < 8d: 8e' ------------ Groove 10
．． 101・・・・・・・・・・・・Lid body 12
......Hydrophilic substance layer 13...
・・・・Cushion material 15・・・・・・・Souffle material 16・・・・・・・Vacuum pump 2α・・・
...Piston Fig. 5 Fig. 6 Fig. 7 Fig. 8 323

Claims (1)

[Scope of Claims] 1) A nozzle head body having a side surface provided with a plurality of grooves for ejecting ink, and a plate-shaped lid body provided in close contact with the side surface of the nozzle head body. An inkjet nozzle head characterized in that the lid body is provided on a side surface of the nozzle head body so as to be openable and closable. 2) The inkjet nozzle head according to claim 1, further comprising a layer of a hydrophilic substance on the inner side surface of the groove. □ 3) The inkjet nozzle head according to claim 1, wherein the lid has a cushioning material on the side that comes into close contact with the nozzle head main body. 4) A nozzle head body with a plurality of grooves provided on the side surface for causing ink to fly, and a nozzle head body that moves between a closed position in close contact with the side surface and a closed position away from the side surface. 1. An inkjet nozzle head comprising a plate-shaped lid that can be provided, and means for urging the lid to be in the closed position except when in use.