JPS64224B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a nozzle head for an inkjet having a plurality of nozzle openings, and particularly to a nozzle head for an inkjet in which the nozzle head is separable into a head body and a lid body. be.

(Prior Art) Conventional printing devices and information output terminals record various types of output information by colliding wire heads, printed characters, etc. with recording paper via an ink ribbon, but they produce noise during recording. is quite large,
When used in relatively quiet offices, etc., it caused noise pollution. In recent years, as an output device to solve these problems, a so-called ink jet type output device has been developed and is generally used, in which liquid ink is ejected by some means and attached to recording paper to record various output information. It's starting. Inkjet systems can be roughly divided into four types: charge control system, ink on demand system, electric field control system, and ink mist system. The charging control method is a method in which ink is constantly ejected in the form of droplets using a vibrator, the ejected ink is charged, and then output information is recorded by deflecting the charged ink droplets using an electric field. It is. The ink-on-demand method is a method in which pressure is applied to an ink reservoir using a piezoelectric element such as a piezo element according to output information, and ink is ejected to form a record on a recording paper. The electric field control method is a method in which a potential is applied between a nozzle opening and a recording paper according to 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 output information, and then uses electrostatic attraction to ionize the ionized ink. This makes it adhere to the recording paper. The nozzle head of the present invention is of the electric field control type.

Conventionally, electric field control type nozzle heads have a single nozzle opening, and therefore, a method has been used in which the entire recording sheet is recorded 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. To solve this problem, a nozzle head with multiple nozzle openings in the line direction is used to automatically scan the nozzle head according to the output information without mechanically scanning the nozzle head.
A method has been proposed in which one line of information is recorded almost simultaneously by selectively applying a potential to a plurality of nozzle openings. In an inkjet recording device equipped with such an inkjet nozzle head having a plurality of nozzle openings, a recording sheet is placed between the nozzle head having a large number of nozzle openings and needle-shaped electrodes having respective electrodes corresponding to each nozzle opening. The inkjet recording device is configured such that the The liquid ink is pressurized by a pressure pump or static ink pressure to form a hemispherical meniscus at the nozzle opening.
By applying a voltage corresponding to the output information to the voltage application terminal and the needle-shaped electrode, that is, by selectively applying a voltage to each electrode of the needle-shaped electrode in accordance with the output information, the voltage is formed at each nozzle opening. The meniscus of the ink selectively flies due to electrostatic attraction and adheres to the recording paper, thereby recording output information.
Furthermore, the recording paper is transported by a feed roller and the output information of the next line is recorded, thereby recording the output information over the entire recording paper.

By using a nozzle head with such a large number of nozzle openings, it is possible to record information for one line almost simultaneously without mechanically scanning the nozzle head itself in the line direction, so various output information can be recorded at high speed. can be recorded.

However, although there is no problem with a nozzle head having multiple nozzle openings as described above when ink is constantly being ejected from the nozzle openings, if the inkjet recording device is not used for a certain period of time, ink may be ejected from the nozzle openings. It has been found that if the ink does not fly for a long time, the water or solvent in the ink in the nozzle area evaporates, causing the ink to solidify and clog the nozzle. Also, once this clogging occurs, it is very difficult to clear it. Such clogging problems have conventionally occurred even in nozzle heads that have a single nozzle opening, but in nozzle heads that have multiple nozzle openings, the frequency of nozzle clogging is proportional to the number of nozzles, and The problem is even more serious than in the case of a nozzle head having a single nozzle, since cleaning must also be performed for each nozzle to eliminate clogging.

In order to eliminate such clogging due to ink solidification, a nozzle is known in which two substrates each having a plurality of parallel nozzle walls formed thereon are stacked so that the nozzle walls face each other (in particular, (No. 42862, 1973). This conventional technique has the advantage that when clogging occurs due to ink solidification, the substrate can be disassembled, that is, the nozzle can be disassembled, and the nozzle can be easily cleaned.

However, since such technology does not reduce clogging, it is necessary to frequently inspect for clogging, and it is extremely troublesome to disassemble and reassemble the board each time to clean the clogging. .

The present invention was developed in view of the above circumstances, and it prevents clogging of nozzles due to ink solidification, reduces the number of times of clogging inspection and clogging cleaning, and makes it extremely easy to clean the nozzles when clogging occurs. It is an object of the present invention to provide a nozzle head for an inkjet that is easy to handle and can be easily handled.

(Means for Solving the Problems) The nozzle head for an inkjet of the present invention has a nozzle head body in which a plurality of grooves are provided on the side surface, and is arranged opposite to the side surface of the main body in which the grooves are provided. The lid is attached so that it can be opened and closed, and the power detection means detects whether the power is turned on or off for inkjet recording, and sends an electric signal indicating the detection result to the operating means, and the operating means opens the lid. The body is moved to a closed position that allows ink to fly based on a signal input indicating a power-on state, and to an open position that facilitates cleaning of clogged grooves from the outside based on a signal input indicating a power-off state. It is characterized by the fact that they are located in different positions.

(Operations and Effects of the Invention) In the inkjet nozzle head of the present invention, the lid is opened and closed from the main body based on the power state for inkjet recording, and ink remains in the nozzle, causing clogging due to ink solidification. Since the lid body and the nozzle head body are designed to open each other in non-recording conditions, it is possible to eliminate the capillary phenomenon of the ink within the nozzle and return the ink to the liquid reservoir, preventing the ink from solidifying in the nozzle. Clogging can be prevented. Therefore, the number of times of checking for clogging and the number of times of cleaning for clogging can be significantly reduced.

Moreover, the opening and closing of the lid automatically detects the power state for ink recording, and the lid automatically opens and closes as appropriate based on this detection result, making the operation extremely easy. Even if a blockage occurs, the operator does not have to disassemble and assemble the nozzle one by one as in the prior art, and can simply clean the nozzle while the lid is open, making the nozzle cleaning extremely easy.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of an inkjet nozzle head of the present invention.

Grooves 2a, 2b, 2 are formed on the side surface of the nozzle head body 1.
Nozzles c, 2d, and 2e are formed, each of which functions as a nozzle for ejecting ink. On the side of the nozzle head body 1 where the grooves 2a, 2b, 2c, 2d, and 2e are formed, a plate-shaped lid 4 is provided, a portion of which is attached to the nozzle head body 1 by a hinge 3. When the inkjet recording device is used, that is, when ink is ejected from the nozzles, the lid 4 is brought into close contact with the nozzle head body 1. When the inkjet recording device is not used, the lid 4 is opened and the nozzles, that is, the grooves 2a, 2b, 2c, 2d are kept in close contact with the nozzle head body 1. , 2e can be removed by returning the ink to the reservoir 5 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 lid 4 can be opened, so the nozzle can be easily cleaned.

Further, this nozzle head is configured to open and close the lid 4 in synchronization with the power on/off operation of the inkjet recording apparatus. That is, as shown in FIG. 1, a coil-shaped spring 6 is installed between the lid 4 and the nozzle head body 1, and biases the lid 4 to open.
Further, a vacuum pump 7 is provided on the nozzle head body 1 side, and by sucking air through a suction hole 8, it is possible to bring the lid body 4 into close contact with the nozzle head body 1. Then, the vacuum pump 7 is operated in synchronization with the power-on operation of the inkjet recording device, and the suction force positions the lid body 4 in a position (closed position) in close contact with the head body 1, and also the power-off operation of the inkjet recording device is performed. By stopping the vacuum pump 7 in synchronization with this, the spring 6 is biased to move the lid 4 to a position away from the nozzle head body 1 (open position).

Further, the power-on and power-off states are detected by the power state detection means 9, and when the power-on state is detected, the vacuum pump operation signal is output from the detection means 9.
When a power-off state is detected, a vacuum pump stop signal is sent out, and the vacuum pump 7 to which these command signals are input is set to an operating state or a stopped state based on these command signals.
As this power supply detection means 9, for example, a solenoid,
A transistor, FET, etc. may be used.

FIG. 2 is a perspective view showing a different embodiment from FIG. 1.

In this embodiment, a part of the lid body 4 is a combination body 12.
It is connected to a piston 11 which can move in and out in the direction shown by arrow 10. Therefore, the piston 11 is operated to bring the lid 4 into close contact with the nozzle head body 1 in synchronization with the power-on operation of the inkjet recording device, and the lid 4 is moved away from the nozzle head body 1 in synchronization with the power-off operation. It becomes possible to operate the piston 11 so as to position it.

Note that the power state detection means 9 functions similarly to that shown in the embodiment of FIG.

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.

Note that the arrangement of the grooves 2 provided in the nozzle head body 1 is not limited to that of the above-mentioned embodiment; for example, as shown in FIG.
2e, 2a' to 2e' may be arranged in a staggered manner. A nozzle head constructed in this manner has a higher resolution than a nozzle head having a groove formed on one side. Two lid bodies 4 are used so as to be brought into close contact with each side of the nozzle head body 1.

Note that it is preferable to provide a layer of a hydrophilic substance on the inner side surface of the groove 2 because the ink can be smoothly transferred through the nozzles and a uniform meniscus can be formed at the opening of each nozzle.

It is preferable to provide a cushion material on the side of the lid 4 that comes into close contact with the nozzle head body 1, since there is no risk of damaging the nozzle head body 1 or destroying the groove 2.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the nozzle head for an inkjet according to the present invention, Fig. 2 is a perspective view showing a different embodiment from Fig. 1, and Fig. 3 shows grooves provided in the nozzle head body arranged in a staggered manner. It is a perspective view which shows the case where it becomes. 1... Nozzle head main body, 2a, 2b, 2c,
2d, 2e, 2a', 2b', 2c', 2d', 2e'...
Groove, 4... Lid, 6... Spring, 7... Vacuum pump, 9... Power state detection means, 11... Piston, 12... Combined body.

Claims (1)

[Scope of Claims] 1. A nozzle head main body having a plurality of grooves provided on a side surface for causing ink to fly; a closed position that is in close contact with the side surface of the nozzle head body to allow ink to fly; and the side surface. a plate-like lid member that is movable between an open position and an open position that facilitates cleaning of the clogged groove from the outside; The operating means to be operated and the power on/off state for inkjet recording are detected, and based on the detection results, the lid body is positioned in the closed position in the power on state and in the open position in the power off state. 1. A nozzle head for an inkjet, comprising a power state detection means for sending an electric signal to the operating means. 2. The operating means includes an elastic means that urges the lid toward the open position, and a vacuum pump that suctions the lid toward the closed position in response to input of an electric signal indicating the power-on state. An inkjet nozzle head according to claim 1, characterized in that: 3. The operating means is a piston that moves the lid body to the closed position in response to an input of an electric signal indicating the power-on state and to the open position in response to the input of an electric signal indicating the power-off state. A nozzle head for an inkjet according to claim 1, characterized in that: