JPS58187359A - System for removing air bubbles in fluid flowline - Google Patents

Abstract

PURPOSE:To make it possible to obtain an image with good quality, in an ink jet printer, by removing a fluid present in a part into which air bubbles are mixed from the opening provided to the terminal end part of the fluid flowline of an ink nozzle head in accordance with the air bubble detection result. CONSTITUTION:In order to detect air bubbles mixed into a pipe 23 between a multi-nozzle head 21 equipped with ink nozzle rows 22 and an ink tank 24, electrodes 28, 29 are respectively arranged to the head 21 and the tank 24. When air bubbles 26 are mixed into the pipe 23 and the supply of an ink is stopped, resistance between the electrodes 28, 29 is increased to a large extent to reduce a current value while the detected output voltage of potential difference from an output terminal 33 through a differential amplifier 32 is extremely lowered. By this detected output, sucking operation is carried out for a predetermined time by a pump 72 to remove mixed air bubbles. When air bubbles can not be removed even if this operation is carried out, an alarm is issued to inform the necessity for performing proper operation for removing mixed air bubbles.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing air bubbles in a fluid flow path, which detects and removes air bubbles mixed in the fluid flow path of an ink pipe connecting an ink nozzle head and an ink tank.
*In addition to automatically removing air bubbles according to the results,
It was designed to remove air bubbles through a predetermined process and to issue a warning when the bubbles are not removed.

1H, if air bubbles get mixed into the fluid flow path, it will have a serious impact on profits and losses.A typical example of this is when ink is ejected from a large number of fine ink nozzles that are opened onto a sheet of paper. There are inkjet printers that print characters, graphics, etc.

This J)l inkjet printer is schematically shown in Figure 1 as 4(
For example, on the carriage l,
From the left in the figure, the multi-nozzle head is numbered /~.
Arrange the toda and set it up, cyan C.

-tze/lMs4 erotic Y? y/ of each color on the black and y/o [protruding], and the multi-nozzle head has -
The ink tank q may be supplied with one color of ink through the r m a pipe 3, respectively, and a flexible 4eMk bell in which a large number of conductive wires are arranged and buried respectively)
~S-3, a drive signal is supplied to each via the relay plate 6 and the general energizing belt. An endless belt in which a carriage l having such a configuration is placed on one guide rail l and connected? Main scanning is performed by driving the carriage by a pulse motor 10 and reciprocating in the X direction in the figure, and at the same time, the paper spread out through the roller pairs /3 and /41 is transferred to the roller pair. /41 is connected to the pulse motor IS to perform sub-scanning by feeding in the Y direction in the figure, and a color image is created by each color ink jetted from each multi-nozzle head coder onto the #ticoat. Record.

In addition, there are stoppers on both sides of the carriage's reciprocating path.
/-/ and //- are placed to determine the range of the king-sho eclipse.

In the inkjet printer configured as described above, the 1llT Buddhist pipe J that connects each of the multi-nozzle heads λ-7 to --+ and the ink tank tray may leak ink during feeding due to the following various reasons. If air bubbles are mixed in,
There is a drawback that the ink ejected from each ink nozzle is interrupted, making it impossible to record, or at least creating a blank space in a part of the recorder, which seriously impairs the quality of the record. That is, if the pipe is left unused for a period of 111 days, air will seep in through the pipes.

The ink that has filled up to the tip of the t2JdM ink nozzle is drawn in for some reason, and air enters from the tip of the ink nozzle.

+31 Due to the air bubbles inside the ink tank, the air that is expanding due to the after-filter valve enters the ink and becomes air bubbles.

(4) The ink in the ink tank enters #it9 from the tip of the pipe inserted into the ink tank.

When using the rice, the ink is interrupted due to the ingress of air bubbles, resulting in tM.
After a defect occurs in the 2tems, the only solution is to use the ink from the part where the air bubbles were mixed in using a pump connected to the appropriate place, fill up the ink for 10 years, and restart the i**w2 relationship. There was also the drawback that there was no benefit.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and detect air bubbles mixed in a fluid flow path such as a flexible pipe connecting an ink nozzle and an ink tank in an inkjet printer. Depending on the result, it will be automatically removed through a predetermined process, and one of the predetermined steps will be removed.
i! Another object of the present invention is to provide a method for removing air bubbles in a fluid flow path in which the tube axis is emitted when the entrained air bubbles cannot be removed.

That is, the bubble removal method of the present invention removes fluid from a portion where bubbles are mixed, for example, by using a pump or the like through an opening provided at the end of a fluid flow path, such as the head of the ink nozzle head mentioned above. When the entrained air bubbles cannot be removed by a predetermined process, it is determined that it is difficult to remove the entrained air bubbles by the predetermined process, and a report is issued.

The present invention will be described in detail below with reference to the drawings.

Here, an example of the configuration and arrangement of a bubble detection device in a fluid flow path is shown in FIG. In the illustrated configuration, in order to detect air bubbles λ6 mixed in the ink in the pipe n that connects the multi-nozzle head l equipped with an ink nozzle row and the ink tank plate equipped with an air filter, Rearrange the electrodes and bumps inside the multi-nozzle head and at the bottom of the ink tank at positions as close as possible to both ends of the ink flow path, and connect the resistors 30 between the electrodes d and 29. For example, Il! from the telephone key, i/! ! , current voltage is applied to both electrodes g, j? The potential difference generated across the resistor 3Q by the current flowing in the fluid, i.e., the ink, present at the differential amplifier 6J- is amplified by the differential amplifier 6J-, and is outputted from the output terminal 33 as a detected output voltage. This detected output voltage is generated when the ink in the pipe n is interrupted due to the ink mixed in at the position shown in the figure, for example, at the electrode 3. As the electrical resistance between the ink and the ink gradually increases, the detection output voltage decreases significantly, and air bubbles mixed in the ink can be easily detected. Even if the ink in the pipe n is not interrupted due to the air bubbles being mixed in, the resistance value exhibited by the ink increases at the part where the air bubbles are mixed, so the detected output voltage becomes yc. It is possible to reliably detect the inclusion of air bubbles.

A third configuration example of a control device for removing entrained air bubbles according to the method of the present invention, which removes entrained air bubbles according to changes in the detection output voltage that occur when air bubbles enter the pipe n etc. as described above. Draw on the diagram.

In the illustrated configuration, the bubble detection output voltage is input to the input terminal 34!, for example, by the circuit configuration as described in detail with reference to FIG.
From the timer circuit, 4< to 33. The activation signal is supplied to the pump drive 1MJ4 over the timer period, and the drive signal is applied to the bongoo 7 over the predetermined period of time. If the entrained air bubbles are removed by the operation of the pump core for the predetermined period of time and the air bubble detection output voltage no longer enters the input terminal, the control circuit shown in the figure remains stopped and enters a standby state.

However, when the air bubbles are not removed even by the suction operation of the bongoo 7 for a predetermined period of time as described above, and the air bubble detection output voltage still comes in, the air bubble detection output voltage is ANDed through the timer circuit 3S. At the same time, a pump stop signal generated by the pump stop detection circuit 37 in accordance with the amplitude of the operation signal from the pump core is also supplied to the AND circuit. In response to the existence of entrained air bubbles that cannot be removed even by the above, the AND output signal generated by the alarm circuit 39 is sent to the alarm circuit 39 to urge the Ministry of Public Cleansing to take measures to thoroughly remove the entrained air bubbles. do.

In addition, multi-nozzles in inkjet printers,
Ink flowing in the pipe between the ink tanks (sleep-1)
In general, for fluids that flow through thin tubes and reduce the electrical resistance value at the southern limit, the same procedure is used as described above. Excessive air bubbles can be removed and an alarm can be issued to take appropriate action.

As is clear from the above djlJ, according to the present invention,
The column is the ink nozzle l in an inkjet printer.
vlckv is a pipe that connects yi and ink tank.
The air bubbles mixed into the Ft foam are immediately detected at the time of air 1181 being mixed in, and the bubble removal operation is performed according to a predetermined process, and the mixed air bubbles can be automatically and easily removed. If there is excessive air bubbles that cannot be stopped, a warning can be issued and appropriate measures can be taken without delay.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the general configuration of an inkjet printer, FIG. 1 is a diagram showing an example of the configuration and arrangement of a bubble detection device in a fluid fi junction according to the present invention, and FIG. 3 is a diagram according to the method of the present invention. It is a block diagram showing a configuration example of a bubble removal circuit in a fluid flow path. l...carriage, 1-l~coder...multi-nozzle head, 3...l
Tl1il sex pipe, da... ink tank!
-/ -j-da...OTl@Tl-belt, 6...
Relay plate, ri...sozen-belt, t...
・Guide rail, 9...Endless belt, 10,
/1...Pulse motor, //-/, //--...Stopper, l...
ml paper, /, 3, / da... roller pair, -7... multi-nozzle head, -... ink nozzle 11. J.? ...pipe, review...ink tank, correction...air filter,
Koto...bubble, -7...pump, -ν°...electrode, 30...resistance, 3/...
...''Turtle w1 3-...Differential amplifier, 33.
...Output terminal, 3da...Input terminal, 3j...
・Timer circuit, 36...Pump drive circuit, 37
...Bong return detection circuit, J-and circuit, 39...wi-information circuit. Patent applicant Canon Co., Ltd.

Claims (1)

[Scope of Claims] 1) In detecting and removing air bubbles mixed into a fluid flow path, the fluid in the portion where the air bubbles have been mixed is detected through an opening provided at the terminal end of the fluid flow path, and the result of the air bubble detection is detected. A bubble removal method in the fluid flow path that removes 5% mold according to the amount of mold. 2)%#! 1-Claim 1 In the Ajiroki method of Kihon, if the body is continuously removed from the opening for a predetermined period of time according to the result of 1IIk2 bubble detection, and 4. A method for removing air bubbles in a fluid flow path, which is characterized in that a warning signal is emitted in response to the detected air bubbles obtained by softening the rice according to conditions.