JPH06135004A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To provide an ink jet recorder having delivery recovering function for recovering from abnormal delivery of ink due to clogging of the ink delivery opening of a recording head with dust or the like, increase of viscosity of ink, or mixture of bubbles, and removing the cause of abnormal ink delivery due to ink droplet or foreign matter adhered around the ink delivery opening. CONSTITUTION:The ink jet recorder comprises a recording head 1 having a plurality of ink delivery orifices 10, and a unit for sucking ink through the ink delivery orifice 10. The ink suction unit comprises a section 8 for sucking ink while covering a part of the plurality of ink delivery orifices 10, a guide screw 19 for moving the sucking section 8 on the surface of the ink delivery orifice 10, and a drive motor 20 therefor.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a recording liquid (ink).
The present invention relates to an inkjet recording apparatus including a recording head in which a plurality of ink ejection openings for ejecting ink are arranged in a predetermined direction.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing an example of a recording head provided in the above ink jet recording apparatus.

Reference numeral 1 denotes an ejection element, which supplies nozzles in which heat-generating elements for exerting ejection energy on ink are arranged in parallel, orifices 10 which are openings for ejecting ink in front of each nozzle, and each nozzle. A common liquid chamber or the like in which the ink is stored is provided, and the ink is ejected by the orifice 10 to form a recording droplet.

Reference numeral 3 is a base plate for fixing the discharge element 1 by adhesion or the like, and 2 is a front plate fixed to the end surfaces of the discharge element 1 and the base plate by tightening members such as bolts, and has an opening for directly facing the recording medium to the orifice 10. Reference numerals 15, 16 and 17 are members forming a part of the ink supply system, and 15 is the ejection element 1.
An elbow-shaped connecting member for introducing ink into a common liquid chamber therein, 17 is a filter unit disposed in the middle of an ink supply path from an ink tank or the like as an ink supply source, 16
Is a supply pipe connecting the connection member 15 and the filter unit 17.

FIGS. 6 and 7 are a longitudinal sectional view and a lateral sectional view of the recording head shown in FIG. 5, respectively, and a cap member covering the entire orifice opening surface of the ejection element 1 through the front plate 2 in the ejection recovery process. The state which joined 4 was shown.

Nozzle 1 corresponding to a plurality of orifices 10
2 is connected to a portion 13 called a so-called eaves portion, and the eaves portion 13 is connected to a common liquid chamber 14. Reference numeral 11 denotes an energy generating element that is provided in the nozzle 12 and applies ejection energy to the ink, and is formed of, for example, a heating element. Inside the filter unit 17, a filter 18 made of, for example, a ridge mesh is provided in order to remove minute dust and air bubbles.

FIG. 8 is a block diagram showing an ejection recovery system in a conventional ink jet recording apparatus. In a normal recording state, the cap member 4 is set at an appropriate position that does not hinder the recording operation, the valve B2 is closed, the valves B1 and B3 are kept open, and the ejection element 1 is discharged from the ink tank 6 through the valve B1. Ink is supplied by capillarity.

When the discharge recovery process is performed, the cap member 4 is attached to the discharge element 1 and the valve B1 is closed.
The valves B2 and B3 are maintained in the open state, and in this state, the pump 7 is driven to pressure-feed the ink from the ink tank 6 into the ink supply path, supply the pressurized ink to the ejection element 1 and force it from the orifice 10. Inject ink into the.
At this time, dust, thickened ink,
Bubbles and the like are ejected from the ejection element 1 together with the ejected ink. For example, as shown in FIG. 7, minute bubbles a that have penetrated into the nozzle 12 are removed from the orifice 10 together with the ink by driving the pump 7. Therefore,
The ink ejected from the orifice 10 is received by the cap member 4 and guided to the waste ink tank 5.

[0009]

FIG. 9 shows a fluidics equivalent circuit of the ink of the conventional apparatus during the ejection recovery process. Here, the pressing force is ΔP, the number of nozzles is n, the fluid resistance per nozzle 12 is R1, the fluid resistance of the eaves portion 13 is RH, the fluid resistance of the common liquid chamber 14 is RC, and the fluid resistance of the filter portion 17 is RF, the fluid resistance from the ink tank 6 other than the filter unit 17 to the common liquid chamber 14 is RS,
Assuming that the flow rate per nozzle 12 when pressurizing with the applied pressure ΔP is q, the following relationship is established during the ejection recovery process.

ΔP = qR1 + nq (RH + RC + RF + RS) (1) ∴q = ΔP / {R1 + n (RH + RC + RF + RS)} (2) Normally, the supply system is designed so that the relationship of R1 >> RH + RC + RF + RS is obtained. In the case of a recording head in which nozzles 12 are arranged in a number corresponding to the width, that is, a so-called full-multi type recording head, the number of nozzles n becomes large and the flow rate q flowing per nozzle becomes extremely small. In addition, as shown in FIG.
When bubbles a, dust, and the like enter into 2, the fluid resistance of the nozzle increases. Therefore, the flow rate of the nozzle having the ejection failure is smaller than that of the normal nozzle.

Therefore, when the conventional ejection recovery system is adopted, the nozzle having the ejection failure may not be returned to the normal state even by the recovery operation, or the recovery process may have to be performed many times. was there.

Further, in order to overcome such a fluid resistance, it is necessary to increase the applied pressure, and therefore it may be necessary to provide a large pump 7, which may increase the ink consumption amount. Furthermore, it has been necessary to increase the strength of the joint portion of each member so as to withstand a large pressure.

Further, in the conventional ejection recovery system, it is possible to remove air bubbles, dust, etc. in the nozzle, but it is difficult to completely remove dust and ink drops attached around the ejection opening. there were.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and clogging of an ink ejection opening of a recording head due to dust or the like, or increase in viscosity of ink, or inclusion of bubbles. It is possible to perform reliable and reliable ejection recovery processing by recovering the ink ejection abnormality caused by, for example, or removing the cause of the ink ejection abnormality due to the ink droplets or foreign substances adhering to the periphery of the ink ejection opening. It is an object of the present invention to provide an inkjet recording device.

[0015]

Therefore, an ink jet recording apparatus according to the present invention comprises a recording head having a plurality of ink ejection openings, and an ink suction unit for sucking ink from the ink ejection openings. The ink suction unit includes a suction unit that covers a part of the plurality of ink discharge openings and sucks ink, and a moving unit that moves the suction unit along the surface of the ink discharge openings. By the configuration characterized by having
It is intended to achieve the above purpose.

[0016]

With the above structure, the ink is ejected from the plurality of ink ejection openings of the recording head to perform the recording operation, and during the ejection recovery operation for recovering the abnormality of the ink ejection, the suction unit provided in the ink suction unit is used. A part of the plurality of ink ejection openings provided in the recording head is covered, and ink is sucked from the covered ink ejection openings. Then, by moving the suction portion along the surface of the ink discharge opening by the moving means provided in the ink suction unit to suck the ink, the discharge recovery of all the ink discharge openings can be performed while partially and efficiently recovering the discharge. It is possible to eliminate the cause of the discharge abnormality by recovering the discharge and cleaning and collecting the ink droplets and the foreign matter attached to the periphery of the ink discharge opening.

[0017]

EXAMPLES An ink jet recording apparatus according to the present invention will be described below with reference to examples.

FIG. 1 is a block diagram showing the construction of the main part of the first embodiment of the present invention, showing the construction of the recording head and ink suction unit during the ejection recovery operation. FIG. 2 is a sectional view of the essential parts of the second embodiment. It should be noted that the same or corresponding parts as those of the conventional device are designated by the same reference numerals, and duplicated description will be omitted.

In this embodiment, a recording head 1 having a plurality of ink ejection openings (hereinafter referred to as orifices) 10 arranged in a straight line and an orifice 1 at the time of ejection recovery operation.
An ink suction unit for sucking ink from 0 is provided.

The ink suction unit includes a plurality of orifices 1.
The suction portion 8 that covers the opening surface portion of a portion of the orifices 10 in 0 and sucks ink, and the suction portion 8
And a moving means including a guide motor 19 and a drive motor 20 for moving the surface in contact with the surface.

The operation of the first embodiment will be described below.

The recording operation is stopped when an instruction for an ejection recovery operation is issued, such as when the recording operation has elapsed for a predetermined time, or when an ink ejection abnormality has occurred, and the suction portion 8 of the ink suction unit is connected to the recording head 1. The ink is sucked from the covered orifice 10 by the suction action of the pump 7 so as to cover the orifice 10 at one end of the plurality of orifices 10 closely. Then, by rotating the guide screw 19 of the moving means by the drive motor 20, the suction portion 8 is moved along the surface of the orifice 10 and the orifice 1 at the other end.
By sucking the ink while moving it to the portion 0, the ink is sequentially discharged from all the orifices 10 while cleaning the opening surface of the suction portion 8, and the discharged ink and the cleaned foreign matter are discarded by the pump 7. It is collected in the waste ink tank 5 via the ink tube 5A.

When the ink is ejected from the orifice 10, the dust in the orifice 10 and the like, the ink of which the viscosity is increased, the bubbles, etc., which are the cause of the ejection abnormality, are ejected together with the ejected ink and the ejection function is restored. It should be noted that the ejection function can be efficiently and completely restored by ejecting ink by sequentially sucking all the orifices 10 partially, not simultaneously.

By moving the suction portion 8 along the surface of the orifice 10, ink droplets and foreign matter adhering to the peripheral portion of the orifice 10 can be cleaned and collected to eliminate the cause of abnormal discharge. .

In addition to the structure in which the suction portion 8 is moved along the surface of the orifice 10 from the orifice 10 portion at one end to the orifice 10 portion at the other end, only the vicinity of the orifice 10 in which ejection failure has occurred is performed. It can also be configured to move.

The surface of the suction portion 8 is preferably made of an elastic material, for example, silicon rubber or the like which is a material that is not easily damaged by the movement of the suction portion 8 or damaged by the surface of the orifice 10. Is desirable. The suction area of the suction unit 8 may be such that it can suck from several tens of orifices, and the pressing force and the moving speed of the suction unit 8 against the surface of the orifice 10 are the strength of the orifice 10, the surface strength of the suction unit 8, The optimum value can be selected based on the ink suction force and the like.

(Other Embodiments) FIG. 3 is a cross-sectional view of essential parts showing an ink supply recovery system of the ink jet recording apparatus of the second embodiment. The same or corresponding portions as those of the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

The suction portion 8 of this embodiment sucks ink from a part of the plurality of orifices. The suction portion 8 is provided with an elastic material blade 9 that comes into contact with the surface of the orifice 10 and bends.

In the above structure, in response to a command for a discharge recovery operation, the suction unit 8 sweeps ink droplets, dust, etc. on the orifice surface from one end of the row of orifices 10 with the blade 9 and sucks empty ink in the orifice 10. While moving to the final end orifice.

That is, the blade 9 is attached to the moving front side of the suction section 8.
By providing the above, since the ink in the orifice can be sucked after the orifice surface is wiped off, bubbles and the like in the nozzle 12 can be surely removed, and good printing can be obtained.

FIG. 4 is a sectional view of the essential parts of the third embodiment.
The same or corresponding portions as those of the second embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

In the third embodiment, as shown, the bread 9
By forming one side portion of the suction portion 8 by means of this embodiment, the structure of the suction portion 8 is simplified, and the embodiment has the same effect as the second embodiment.

According to the present invention, as long as the recording head has a plurality of nozzles arranged, the arrangement range or the number of nozzles corresponds to the entire width of the recording medium or is less than that. Further, it is needless to say that even if it is a full multi-type line printer, a serial printer, or any configuration of the ink supply system, it can be implemented extremely effectively and easily.

Further, the construction of the suction portion 8 and the construction of the moving means are not limited to those in the above-mentioned respective embodiments, but may be constructed.

Further, the detection of the ejection failure or the detection of the orifice position where the failure occurs due to the ejection operation recovery operation command may be performed by the operator's visual observation during normal recording or test recording. Alternatively, the result of test recording or the like on the recording medium may be determined using a reading sensor or the like. In addition, in the above example, the ejection failure is determined after the recording process and the recovery operation is performed, but the ejection function recovery operation is performed immediately after the recording apparatus is turned on or before recording is started after a long period of rest. May be.

The present invention brings excellent effects particularly in a recording head and a recording apparatus of a system utilizing thermal energy among the ink jet recording systems.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged so as to correspond to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal to the electrothermal converter which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling, thermal energy is generated in the electrothermal converter, and the recording head heat acting surface is generated. This is effective because the film can be boiled to the point where, as a result, bubbles can be formed in the liquid (ink) in one-to-one correspondence with this drive signal. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. still,
US Patent No. 4 of the invention relating to the rate of temperature rise of the heat acting surface
If the conditions described in the specification of No. 313124 are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angle liquid passage) as disclosed in the above-mentioned respective specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which the action portion is arranged in a bending region.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a configuration based on Japanese Patent Laid-Open No. 138461/1984, which discloses a configuration that corresponds to the discharge portion.

[0039]

As described above, according to the present invention, the ink is ejected from the plurality of ink ejection openings of the recording head to perform the recording operation, and at the time of the ejection recovery operation for recovering the ink ejection abnormality or the like, The suction portion provided in the ink suction unit covers a part of the plurality of ink ejection openings provided in the recording head, and the ink is sucked from the covered ink ejection openings. Then, by moving the suction portion along the surface of the ink discharge opening by the moving means provided in the ink suction unit to suck the ink, the ink is sucked from all the ink discharge openings, and It is possible to clean and collect ink droplets and foreign matter attached to the periphery.

By ejecting the ink from the orifice, dust in the orifice or the like, ink having increased viscosity, bubbles, etc., which have caused the ejection abnormality, are ejected together with the ejected ink, and the ejection function is restored. It should be noted that the ejection function can be efficiently and completely restored by ejecting the ink by sequentially sucking all the orifices not simultaneously.

By moving the suction portion along the surface of the orifice, ink droplets and foreign matter adhering to the peripheral portion of the orifice can be cleaned and collected, and the cause of abnormal discharge can be eliminated. Highly reliable discharge recovery processing is possible.

The suction portion is configured to move along the surface of the orifice from the orifice portion at one end to the orifice portion at the other end, and is also configured to move only the vicinity of the orifice in which ejection failure has occurred. You can also

The above is a suction unit which is smaller than the conventional one and covers a part of the plurality of ink ejection openings of the recording head, and the movement for moving the suction unit along the surface of the ink ejection opening. It can be configured by means, downsizing of the device,
It is possible to provide an ink jet recording apparatus that can reduce cost.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a first embodiment.

FIG. 2 is a sectional view of an essential part of the first embodiment.

FIG. 3 is a sectional view of an essential part of a second embodiment.

FIG. 4 is a cross-sectional view of essential parts of a third embodiment.

FIG. 5 is a perspective view of a conventional recording head.

FIG. 6 is a vertical sectional view of a conventional recording head.

FIG. 7 is a cross-sectional view of a conventional recording head.

FIG. 8 is a block diagram of a conventional ejection recovery system.

FIG. 9 is a fluid equivalent circuit diagram of a conventional printhead ejection recovery system.

[Explanation of symbols]

 1 Recording Head 5 Waste Ink Tank 6 Ink Tank 7 Pump 8 Suction Part 9 Elastic Material Blade 10 Orifice (Ink Discharge Opening) 11 Heating Element 12 Nozzle 14 Common Liquid Chamber

Claims (3)

[Claims] 1. An inkjet recording apparatus comprising: a recording head having a plurality of ink ejection openings; and an ink suction unit for sucking ink from the ink ejection openings, wherein the ink suction unit comprises the plurality of ink ejection openings. An ink jet device comprising: a suction portion that covers a part of the ink ejection opening in the ink ejection opening to adsorb ink, and a moving unit that moves the suction portion along the surface of the ink ejection opening. Recording device. 2. The moving means relatively moves the suction portion from the ink ejection opening portion at one end of the recording head to the ink ejection opening portion at the other end when the ink jet recording apparatus is in a non-recording operation. The inkjet recording device according to claim 1. 3. The ink suction unit is provided with an elastic member in the suction portion, which comes into contact with the surface of the ink ejection opening portion and bends, and the moving means uses the elastic material as ink when the ink jet recording apparatus is in a non-recording operation. 3. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is in contact with the surface of the ejection opening and is bent to move the suction unit along the surface of the ink ejection opening.