JPH08230203A - Prevention of operation inferiority of ink jet head - Google Patents

Abstract

PURPOSE: To eliminate the blur caused by the emission inferiority of ink even at the initial stage of operation by supplying a current at the time of the rising of a printer or immediately before the start of the printing operation of an ink jet head for a time shorter than the min. valve opening time at a time of printing to instantaneously open a solenoid opening and closing valve. CONSTITUTION: An opening signal is emitted to a control unit opening and closing a solenoid opening and closing valve 11 other than a usual printing control signal at the time of the rising of a printer. When the printer rises, pressurized ink is supplied to a storage chamber 2 from a supply port 6 through a supply hose to be stored therein. A pulse signal is sent to the solenoid 3 of the solenoid opening and closing valve 11 as an opening signal from the control unit simultaneously with the rising of the printer and, when a valve lever 9 is attracted to the solenoid 3 against the pressing and energizing force of a valve spring 10, a valve disc 8 is separated from the side part of the storage chamber 2 of an emitting orifice 4 and the emitting orifice 4 is instantaneously opened and the valve disc applied to the emitting orifice is separated from the emitting orifice to elastically return.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing malfunction of an ink jet head in a printer device.

[0002]

2. Description of the Related Art Generally, an ink jet head in an electromagnetic valve drive type ink jet printer apparatus has a storage chamber for storing prepressed ink, a discharge port opening from the storage chamber toward a printed material, and a discharge port provided in a valve closing direction. When the electromagnetic opening / closing valve is opened for a predetermined time by a valve opening signal from the control device, the prepressed ink is sprayed from the ejection port onto the printed material to a desired size. The dots or lines of are drawn on the printed matter. The size of the dot or the thickness of the line is regulated by the length of time that the solenoid valve is opened.

[0003]

The ink used for the ink jet head in the above-mentioned general printer apparatus has good fluidity because it must respond immediately when the electromagnetic opening / closing valve is opened. In addition, when sprayed on a printed matter such as paper, it quickly permeates and immediately dries.

Further, as shown in FIG. 6, the valve body 1 for closing the discharge port 104 in order to improve ink shortage and eliminate post-sagging.
08 has a strong closing urging force, and when the printer device is started up or is operated after a long time, the valve body 108 urging the discharge opening 104 of the electromagnetic opening / closing valve 111 to close is strong. Deformation or discharge port 10 due to the biasing force
However, there is a problem in that the ink may not be ejected due to defective operation of the valve body 108 due to sticking to No. 4 and printing failure such as blurring may occur.

This malfunction of the valve element can be resolved to some extent by increasing the voltage applied to the electromagnetic on-off valve, but in such a case, the ink jet head heats up and wear is accelerated due to a strong opening / closing operation. Therefore, there is a problem that durability is reduced.

In addition, since the ink dries quickly, the ink remaining in the ejection port is dried when the ejection port is closed, causing clogging, and the ink is immediately ejected when the ejection port is opened. There was also the problem of disappearing. The above-mentioned problems are particularly remarkable when the speed of the printer device is increased.
The present invention has been proposed in view of the above problems, and it is possible to provide a method for preventing malfunction of an inkjet head that can prevent blurring due to defective ejection of ink even in the initial stage of operation without lowering the durability of the printer device. The purpose is to do so.

[0007]

In order to achieve the above object, a method of preventing malfunction of an ink jet head according to the present invention is a method for preventing pre-pressurized ink from being stored in an ink jet head of a printer device. An inkjet head having a discharge port that opens toward a printed matter and an electromagnetic opening / closing valve that urges the discharge port in a valve closing direction, and the control device controls the opening / closing of the electromagnetic opening / closing valve. The electromagnetic opening / closing valve is instantaneously opened by energizing for a shorter time than the minimum valve opening time at the time of printing and / or immediately before the start of printing operation of the inkjet head.

[0008]

In the method for preventing malfunction of the ink jet head according to the present invention, first, when the printer device is started up, prepressurized ink is supplied from the reservoir chamber. Next, when the printer device is started up, when the printer device is started up, the electromagnetic opening / closing valve is momentarily opened by energizing for a shorter time than the minimum valve opening time at printing. At the same time, the electromagnetic on-off valve closing the discharge port is actuated in the valve opening direction and in the instantaneous valve opening direction against the biasing force.

When the electromagnetic opening / closing valve is thus actuated in the valve opening direction to the instantaneous valve opening direction, the valve element that has been stuck to the discharge port is separated from the discharge port, and the valve element that has been elastically deformed elastically returns. At the same time, ink is supplied between the valve body and the discharge port to improve the seating property of the valve body on the discharge port and to lighten the operation of the valve body.

Further, when the valve body of the electromagnetic on-off valve is instantaneously separated from the discharge port, a part of the ink supplied between the valve body and the discharge port wets the dried ink at the discharge port and prints. The ink passage of time is improved. Immediately before the printing operation of the inkjet head is started, immediately before each inkjet head is actually operated, the electromagnetic opening / closing valve is instantaneously opened by energizing for a shorter time than the minimum valve opening time at the time of printing. The above-mentioned operation is performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for preventing malfunction of an inkjet head according to the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view of an inkjet head mounted and used in a printer device (not shown), and FIG. 2 is a vertical cross-sectional side view of the inkjet head, in which reference numeral 1 generally indicates the inkjet head.

The ink jet head 1 comprises a storage chamber 2 for storing ink and a solenoid 3 at the other end. The storage chamber 2 is made of synthetic resin and has a small capacity. The ink discharge port 4 is formed in a cylindrical shape on the front wall 3 of the storage chamber 2, and the pressure below the discharge port 4 is preloaded by a preload device (not shown). A supply port 6 through which the ink is supplied through a supply hose 5 is formed.

An opening / closing valve 7 is provided at the portion of the discharge port 4 on the reservoir chamber 2 side. The on-off valve 7 is wound around a valve body 8 having elasticity such as silicon rubber that abuts the discharge port 4 and a valve rod 9 and a valve spring 10 that urges the valve body 8 in a valve closing direction. When the valve rod 9 is attracted by the solenoid 3 against the pressing biasing force of the valve spring 10, the valve body 8 is separated from the reservoir 4 side portion of the discharge port 4 and the discharge port 4 is opened. The valve body 8, the valve spring 10, the valve rod 9 and the solenoid 3 for operating the valve body 8 form an electromagnetic opening / closing valve 11.

In addition to the normal print control signal P shown in FIGS. 3 and 4, the control device 12 for opening and closing the electromagnetic opening / closing valve 11 receives the opening signal p shown in FIG. 5 when the printer device is started up. It is supposed to be emitted. Here, the normal printing control signal P is applied at a voltage of 40 V and the applied printing time is 1.2 mse.
c (normal diameter dot D1 in FIG. 3) to 0.6 msec (small diameter dot D2 in FIG. 4), whereas aperture signal p in FIG.
Is a pulse signal that opens with an electric charge of 40 V for 0.3 msec.

The operation of the ink jet head 1 formed as described above will be described below. First, when the printer device is started up, prepressed ink is supplied from the supply port 6 through the supply hose 5 to the storage chamber 2 and is stored therein. Then, at the same time when the printer device is started up, a pulse signal p of 0.3 msec with a charge of 40 V is sent as an opening signal from the control device 12 to the solenoid 3 of the electromagnetic opening / closing valve 11 as shown in FIG. When the solenoid 3 is attracted against the pressing force of the spring 10, the valve body 8 is separated from the portion of the discharge port 4 on the reservoir chamber 2 side, and the discharge port 4 is instantaneously opened. Here, the number of pulse signals p is not limited to a plurality of pulse signals p as shown in FIG. 5, and needless to say, may be one.

When the discharge port 4 is opened instantaneously,
The valve body 8 which has been stuck to the ejection port 4 is separated from the ejection port 4, the elastically deformed valve body 8 elastically returns, and ink is supplied between the valve body 8 and the ejection port 4. The ink acts as a lubricating oil to improve the seatability of the valve body 8 on the discharge port 4 and lighten the valve opening operation of the valve body 8. Further, when the valve body 8 of the electromagnetic opening / closing valve 11 is momentarily separated from the discharge port 4,
A part of the ink supplied between the valve body 8 and the ejection port 4 wets the dry ink at the ejection port 4 to improve the passage of the ink during printing.

In the above embodiment, the pulse signal p is 40
The opening signal for instantaneous valve opening is 0.3 msec with the electric charge of V, but the voltage and the valve opening time are variously changed depending on the type of ink, the diameter of the ejection port, and the like. That is,
The pulse signal p, which is an opening signal, may be in a range that does not eject ink from the ejection port 4 in a shorter time than the smallest dot during normal printing.

Further, in the above embodiment, at the same time when the printer apparatus is started up, the control device 12 causes the electromagnetic opening / closing valve 11 to start.
The opening signal p is transmitted to the solenoid 3 of the valve body 9 and the valve rod 9 is attracted against the pressing force of the valve spring 10 to cause the valve body 8 to move.
Is separated from the portion of the discharge port 4 on the storage chamber 2 side to instantaneously open the discharge port 4, but this is energized for a shorter time than the minimum valve opening time at the time of printing immediately before the start of the printing operation of the inkjet head 1. Then, the valve body 8 of the electromagnetic opening / closing valve 11 may be opened instantaneously.

In this case, although not shown, for example, a plurality of ink jet heads 1 for ejecting a predetermined color such as a full-color printer device are provided, and even if the operation interval of each ink jet head 1 becomes long, characters and pictures are blurred. The inkjet head 1 can be operated immediately without being damaged, which is very useful. Further, it is needless to say that the opening signal p may be generated when the printer device of the above-described embodiment is started up, and the opening signal p may be generated even before the operation of the inkjet head.

[0020]

As described above, the method for preventing defective operation of the inkjet head according to the present invention is performed when the printer device is started up and / or when the printer device is started up before printing. Since the solenoid on-off valve is opened instantaneously by energizing for a shorter time than the minimum valve opening time, the valve element that has been stuck to the discharge port so far is separated from the discharge port and is elastically deformed. In addition to elastically returning, ink is supplied between the valve body and the ejection port to improve the seating property of the valve body on the ejection port, and to lighten the operation of the valve body. This eliminates the need to increase the urging force that presses the valve body of the electromagnetic on-off valve toward the discharge port, and the valve body may be deformed or stuck due to the strong valve closing urging force as in the past. There is an advantage in that it is possible to prevent the problem that the defective ejection of the ink due to the defective operation of the body causes the defective printing such as blurring.

Further, since the valve body can be operated lightly, it is not necessary to increase the voltage applied to the electromagnetic opening / closing valve, and heat generation of the ink jet head due to application of high voltage and early wear due to strong opening / closing operation are eliminated. There is also an advantage that the durability can be greatly improved.

Further, when the valve body of the electromagnetic on-off valve is momentarily separated from the ejection port, a part of the ink supplied between the valve body and the ejection port wets the dried ink at the ejection port and prints. Since the ink flow at the time is improved, the ink can be immediately ejected when the ejection port is opened at the time of printing, and there is also an advantage that beautiful printing can be performed from the initial stage.

In addition, before the operation of the ink jet head is started, the electromagnetic opening / closing valve is instantly opened by energizing for a shorter time than the minimum valve opening time at the time of printing, such as a full color printer in a personal computer. In addition, it has a remarkable effect in preventing the initial malfunction of an inkjet head that ejects a color that is used only occasionally.

[Brief description of drawings]

FIG. 1 is an overall perspective view of an inkjet head.

FIG. 2 is a vertical sectional side view of an inkjet head.

FIG. 3 is an aperture signal diagram.

FIG. 4 is a print control signal diagram for forming dots of a normal diameter.

FIG. 5 is a print control signal diagram for forming small-diameter dots.

FIG. 6 is an enlarged cross-sectional view of a valve body portion of a solenoid valve according to a conventional example.

[Explanation of symbols]

 1 ... Inkjet head 2 ... Storage chamber 4 ... Discharge port 11 ... Electromagnetic on-off valve 12 ... Control device

Claims (1)

[Claims] 1. An ink-jet head of a printer device, a storage chamber for storing prepressed ink, a discharge port opening from the storage chamber toward a printed matter, and an electromagnetic opening / closing valve biasing the discharge port in a valve closing direction. In an inkjet head configured to control opening / closing of the electromagnetic opening / closing valve by a control device, a minimum valve opening time at printing is set at the time of startup of the printer device and / or immediately before the start of printing operation of the inkjet head. A method for preventing malfunction of an inkjet head, characterized in that the solenoid on-off valve is opened instantaneously by energizing for a short time.