JPH089232B2 - Inkjet device recovery method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering an inkjet device, which recovers the ink ejection state of the inkjet head by sucking ink from an orifice of the inkjet head of the inkjet device.

[Summary of Disclosure] The present specification and the drawings show a first method of covering a orifice for ejecting ink and performing recording with a cap and sucking ink from the orifice through the cap in the recovery method of the inkjet device. A second step of sucking ink in the cap in a state where the inside of the cap is in communication with the atmosphere, and a third step of separating the cap and the orifice so that the recording is possible
Steps, a fourth step of ejecting ink from the orifice into the cap when the recording is not performed for a certain time, and an excessive amount of ink in the cap is prevented by the fourth step. Therefore, by including a fifth step that performs the same step as the second step, it is possible to prevent the recording surface from being contaminated due to excess ink dripping inside the cap when the cap is opened (during separation), and when the cap is opened. It is possible to prevent the meniscus of ink in the orifice from receding due to a rapid change in atmospheric pressure around the orifice of the head, and to prevent air from penetrating and causing ink ejection failure.
Further, there is disclosed a technique capable of ejecting ink from an orifice into a cap to obtain an appropriate ejection state when recording is not performed for a certain period of time, and also in that case, it is possible to prevent excess ink from dripping in the cap. Is.

[Prior Art] A liquid jet recording apparatus (inkjet apparatus) is generally called an inkjet printer, and includes a recording head (inkjet head) on a carriage that reciprocates along a recording sheet, and an orifice of the recording head. Ink as a recording liquid is ejected to form flying droplets, and recording is performed using these droplets.

When air bubbles are mixed in the ink flow path provided in the recording head of this type of liquid jet recording apparatus, and when clogging occurs in the orifice at the tip of the ink flow path or in the vicinity thereof, the carriage is recorded. At a predetermined position not facing the surface, for example, at the home position, ink is sucked from the orifice portion by the suction recovery device provided on the device side to remove bubbles and clogging.

Such a suction recovery device has a cap for covering the orifice portion of the recording head, the cap and the pump are connected by a tube, and the pump is driven to suck the negative pressure of the ink from the orifice portion. The structure is adopted.

[Problems to be Solved by the Invention] However, in such a suction recovery device, when negative pressure is sucked from the orifice portion, excess ink may adhere to cover the orifice portion, resulting in ink ejection. At times, the presence of this ink results in an extremely unstable ejection state.

There is also a proposal to install an ink absorber inside the cap and press the absorber against the orifice arrangement to absorb and remove the attached ink. There is also a possibility of pushing in, and dust adhering to the absorber side is displaced to the orifice portion, which may cause discharge failure.

Further, when the cap is opened, recording stains may occur due to excess ink.

[Means for Solving Problems] In the present invention, in order to solve the above-mentioned problems, an orifice for ejecting ink to perform recording is covered with a cap, and the ink is discharged from the orifice via the cap. A second step of sucking ink in the cap in a state where the inside of the cap is in communication with the atmosphere, and a state in which the recording is possible by separating the cap from the orifice. A third step, a fourth step of ejecting ink from the orifice into the cap when the recording is not performed for a certain time, and an excessive amount of ink in the cap due to the fourth step. In order to prevent this, a method for recovering an inkjet device is used, which comprises a fifth step of performing the same step as the second step.

[Operation] According to such a recovery method, the excess ink sucked into the cap in the first step of covering the orifice with the cap and sucking the ink from the orifice is in a state where the next cap is in communication with the atmosphere. Since the ink in the cap is discharged in the second step of suction, when the cap is opened (when separated)
There is no excess ink dripping in the cap and it is possible to prevent the recording surface from being contaminated. Further, since the inside of the cap is communicated with the atmosphere before the third step of separating the cap from the orifice, the atmospheric pressure does not suddenly fluctuate around the orifice of the head when the cap is opened, and the ink in the orifice due to this does not change. It is possible to prevent the meniscus from retracting and air from entering.

Further, when recording is not performed for a certain period of time, a proper ejection state can be obtained by the fourth step of ejecting ink from the orifice into the cap. Further, the excess ink ejected into the cap at that time is the same as the second step
Since the ink is discharged in the process, excess ink does not drop in the cap in this case as well, and the recording surface can be prevented from being contaminated.

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

FIG. 2 shows a liquid jet recording apparatus 1 to which the present invention is applied.
An example is shown.

In FIG. 2, reference numeral 1 denotes a recording head that has an ink storage portion supplied from an ink supply source, a flow path for ejecting the stored ink, and an orifice formed at the tip of the ink storage portion. A means for generating energy for jetting, for example, a piezoelectric element which is one of electromechanical converters, an energy converter which includes a heating resistor which is one of electrothermal converters, and the like are provided.

The number of the recording heads 1 is one in the case of monochromatic recording, but in the case of color recording, for example, it is 4 depending on the color of the ink.
Provide one.

These recording heads 1 are mounted on a carriage 2, and the carriage 2 is provided slidably along two guide shafts 18.

A flexible cable 6 is connected between the recording head and the carriage 2, and a control signal for the recording head is sent.

Although not shown, the carriage 2 is connected to a wiring for inputting a signal from the apparatus main body.

The carriage 2 is fixed in the middle of the endless belt 14, and the belt 16 is moved by the motor 16 to reciprocate the carriage 2.

One pair of rollers 10 and 10 in parallel with the guide shaft 18
12 and 12 are provided so as to face the carriage 2, and the recording paper P is guided while being sandwiched between the rollers.

A paper feed motor 8 is fixed to one end of the roller 10 to feed the recording paper P.

On the other hand, a suction recovery device 20 is provided at the home position indicated by the symbol H.

An embodiment of this suction device is shown in FIGS. 1 and 3.

That is, the suction recovery device 20 is assembled with the substrate 20a as a reference, and the motor 25 is fixed to one part thereof.

Pinion gear 25a fixed to the output shaft of this motor 25
Meshes with the gear 25b, and a pinion gear (not shown) integrated with the gear 25b meshes with the gear 25c.

The pinion gear 25d fixed to the rotating shaft of the gear 25c is a gear.
It meshes with 24b.

A first cam plate 24 is fixed integrally with the gear 24b, and a second cam plate 19 is fixed coaxially with the gear 24b between the first cam plate 24 and the gear 24b.

Two trapezoidal cams 24a are provided on the upper surface of the first cam plate 24 so as to be circumferentially separated from each other by a predetermined angle.

Further, a cam portion 24d forming a ventilation opening / closing portion is provided in a protruding manner on the peripheral surface of the first cam plate 24 in a symmetrical state.

Further, a cam portion 24c is also provided on the peripheral surface of the second cam plate 19, and the cam portion 24c is detected by the detection switch 30 including a micro switch or the like.

On the other hand, the reference numeral 29 is a pump lever, which is rotatably supported in the middle of a support frame 29a protruding from the substrate via a shaft 29b.

A roller 29c for riding on a cam 24a protruding from the first cam plate 24 is provided at one end of the pump lever 29, and the other end is in contact with the piston 26a of the pump 26 via a protrusion 29d. ing.

The piston 26a is constantly given a force in a protruding direction by a spring provided in the pump, and the roller 29c side is always in contact with the first cam plate 24.

On the other hand, the reference numeral 21 denotes a cap holder, to which a plurality of caps 22a to 22d made of an elastic member such as rubber are fixed.

Each of the caps 22a to 22d is provided with an ink absorber 37 below the inside thereof, and each cap has a tube 27a.
Separately connected to the pump 26 via ~ 27d.

The cap holder 21 is slidably provided on the substrate 20a, and is pumped by a spring (not shown).
Always pressed in a direction away from 26.

A gear 23 is rotatably supported below the cap holder 21.

An inner cam 23a is formed on the upper surface of the gear 23, and a shaft 21a protruding from the lower end of the cap holder 21 is in contact with the inner cam 23a via a roller.

Therefore, as the gear 23 rotates, the cap holder 21 is repeatedly pushed back to the pump 26 side by the protrusion of the cam 23a.

The position of the cap holder 21 is detected by the switch 31.

On the other hand, each of the caps 22a to 22d is a tube for sucking ink.
In addition to 27a-27d, it has ventilation tubes 28a-28d.

The other ends of the ventilation tubes 28a to 28d are fixed to a support frame 21b that is integral with the cap holder 21 and between the first cam plate 24 and a rubber plug 32, as shown in FIG.

In addition, the rotation lever 3 is attached to the upper end of the support frame 21b via the shaft 36.
The upper end of 5 is rotatably supported.

The lower end of the rotating lever 35 is at a position facing the first cam plate 24, and has a plug 33 at a position facing the rubber plug 32.

The rotating lever 35 is pressed toward the first cam plate 24 by the return spring 35a, the stopper 33 is pressed toward the rubber stopper 32 by the spring 33a, and the movement limit thereof is restricted by the stopper 33b.

Next, the operation of this embodiment configured as described above will be described with reference to the timing chart of FIG.

FIGS. 5 (A) to 5 (I) are for explaining the operation timings of the respective switches, cams and the like. When the caps are opened, that is, the caps 22a to 22d are recorded away from the orifice portion of the recording head (not shown). All control operations are performed during one revolution of the first and second cam plates 24, 19 from the possible state.

That is, while the first and second cam plates integrated with the gear 24b make one revolution, the gear 23 also makes one revolution, and the cap is in the closed state as shown in FIG. As shown in FIG. 7E, the switch 31 for detecting the opening / closing of the cap is in the OFF state.

Then, the state where the cam portion 24d does not contact the turning lever 35,
That is, the cap is attached to the orifice portion while the tubes 28a to 28d are ventilated.

Then, as shown in FIG. 5 (C), the roller 29c of the pump lever 29 rides on the cam 24a while the ventilation is closed, that is, the cam portion 24d pushes the rotating lever 35 and the rubber stopper 32 is closed by the stopper 33. The pump lever 29 is rotated counterclockwise in FIG. 1, and the first suction operation by the pump 26 is performed. This state is shown in FIG.

Eventually, when the cam 24d is separated from the rotating lever 35 and the ventilation tubes 28a to 28d are in the ventilation open state, the roller 29c of the pump lever 29 rides on the other cam 24a, and the second pump suction operation is performed. .

At this time, so-called empty suction is performed, and the excess ink sucked into the caps 22a to 22d is sucked to the pump side together with the air in the ventilation tubes 28a to 28d.

As shown in FIG. 5B, the waste ink discharge port (indicated by reference numeral 34 in FIG. 1) can be discharged during the suction operation.

Further, during the idle suction operation, the ink held in the ink absorber 37 in the cap and the ink adhering to the tip of the orifice are simultaneously sucked to the pump side.

Further, the normal cap opening / closing operation shown in FIG. 5 (G) is automatically performed by a timer to prevent drying of the orifice portion and adhesion of dust, and when recording is not performed for a certain period of time, an empty suction is performed at the ventilation position. To be executed. Then, after that, by the recording command, it moves as shown by the dotted line in FIG. 5 (G), the cap is opened and the recording state is set.

On the other hand, even during normal use, when the power is turned on, the ink may be preliminarily ejected into the cap in order to obtain the proper ejection state of the ink after the non-recording state has passed for a certain time, At this time, the ink amount in the cap becomes excessive, ink adheres to the tip of the orifice, and ejection becomes unstable, or stains are caused by dropping excess recording paper when the cap is opened.

In order to prevent this, idle suction in the aeration state as described above is performed according to a command from a control device (not shown) to stabilize ink ejection.

Further, since the cap is always opened and closed in the vented state, it is possible to prevent the meniscus of the orifice from retracting due to an increase in the air pressure during the capping operation.

[Effect] As is clear from the above description, according to the present invention, in the recovery method of the inkjet device, the orifice for ejecting ink to perform recording is covered with a cap, and the orifice is inserted from the orifice via the cap. A first step of sucking ink, a second step of sucking ink in the cap while the inside of the cap is in communication with the atmosphere, and a state in which the recording is possible by separating the cap from the orifice. And a fourth step of ejecting ink from the orifice into the cap when the recording is not performed for a certain period of time, and the ink amount in the cap becomes excessive by the fourth step. A fifth step for performing the same step as the second step in order to prevent
Since the method having the above is adopted, excess ink is not dropped inside the cap when the cap is opened (during separation), and it is possible to prevent the recording surface from being contaminated. Further, when the cap is opened, the atmospheric pressure does not change rapidly around the orifice of the head, whereby the receding of the ink meniscus in the orifice and the invasion of air can be prevented, and the occurrence of ejection failure due to this can be prevented.

In addition, when recording is not performed for a certain time, ink can be ejected from the orifice into the cap to obtain a proper ejection state, and in this case as well, there is no excess ink dripping in the cap. Prevents dirt on the surface.

In addition, in the present invention, since the common recovery mechanism of the cap and the pump is used from the first step to the fifth step, the number of parts of the device can be relatively small, and the device can be simplified accordingly, so that the reliability of the device is improved. improves.

[Brief description of drawings]

1 is a perspective view of a suction recovery device, FIG. 2 is a perspective view of a main part of a recording device to which the present invention is applied, and FIG. 3 is a suction recovery device. FIG. 4 is a plan view of the apparatus, FIG. 4 is a side view of the ventilation opening / closing mechanism, and FIGS. 5 (A) to (I) are timing charts for explaining the operation. 1 ... Recording head, 2 ... Carriage 19 ... Second cam plate, 20 ... Suction recovery device 21 ... Cap holders 22a-22d ... Caps 23, 24b ... Gears, 24 ... First cam Plate 25 …… Motor, 26 …… Pump 27a to 27d …… Tube 28a to 28d …… Ventilation tube 29 …… Pump lever 32 …… Rubber stopper, 35 …… Rotating lever 37 …… Absorber

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-60-11365 (JP, A) JP-A-57-117964 (JP, A) JP-A-60-151059 (JP, A) JP-A-59- 78858 (JP, A) JP 58-194568 (JP, A) JP 58-177369 (JP, A)

Claims (4)

[Claims] 1. A first step of covering an orifice for ejecting ink to perform recording with a cap, and sucking ink from the orifice through the cap; and a step of communicating the inside of the cap with the atmosphere. A second step of sucking the ink in the cap; a third step of separating the cap and the orifice from each other so that the recording is possible; A fourth step of ejecting ink into the cap, and a fifth step of performing the same step as the second step in order to prevent the amount of ink in the cap from becoming excessive by the fourth step. A method for recovering an inkjet device, comprising: 2. The recovery method for an ink jet device according to claim 1, wherein a plurality of sets of the orifice and the cap for covering the orifice are provided. 3. An electromechanical converter is used as an energy generating means for generating energy used for ejecting ink from the orifice.
Item 6. A method for recovering an inkjet device according to the item. 4. The method for recovering an ink jet device according to claim 1, wherein an electrothermal converter is used as an energy generating means for generating energy used for ejecting ink from the orifice.