JPH06143554A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To thoroughly recover a discharging function of ink of all nozzles of a line printing head without irregularity in the same state as ink forcible suction of the nozzles of the head of a serial type. CONSTITUTION:A line print head 8 having many nozzles 9 in an entire width of a printing area is movably provided over a printing position P and an ink discharge recovery position Q, a belt so movable in a longitudinal direction of the head 8 as to be brought into contact with the overall ink discharge part of the nozzles 9, an opening is so formed at the belt as to correspond to the nozzles 9 of part of a longitudinal direction of the head 8, and air sucking means 23 is connected to the opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having a line print head having a large number of nozzles over the entire width of a print area.

[0002]

2. Description of the Related Art In such an ink jet recording apparatus, when ink coagulates in the nozzles of a line print head or the viscosity of the ink becomes high, a non-ejection of the ink occurs and the print quality such as blurring of the printing occurs. Therefore, a position apart from the print position is set as the ink discharge recovery position, and discharge recovery means for forcibly sucking the ink in the nozzle is provided here, while the ink discharge recovery position and the print position are The print head is movably provided over the print head, and the print head is switched to the ink ejection recovery position as necessary to forcibly suck the ink in the nozzle to normalize the nozzle.

By the way, in the conventional ink ejection recovery means, a cap is provided so as to cover the entire nozzles of the print head switched to the ejection recovery position, and air suction means for making the inside of the cap a negative pressure is provided. The nozzles are targeted for ejection recovery, and the ink in the nozzles is ejected at once.

[0004]

However, the number of nozzles is four.
Even if it is a serial type print head of about 8 to 128, for example, a line print head corresponding to A4 size has about 3000 nozzles, and the clogging condition is different for each nozzle, and the suction of ink is difficult. There are some that are performed well and some that are not, and it is impossible to recover ink ejection at once with such a huge number of nozzles, and unevenness in ink ejection recovery occurs. However, there was room for improvement in that effective ink ejection recovery could not be expected.

The present invention provides a line printing type ink jet recording apparatus with a function capable of achieving an effective ink ejection recovery similar to that for a serial type printing head by a reasonable improvement. Has an aim.

[0006]

In order to achieve the above object, the present invention provides a line print head movably between a printing position and an ink ejection recovery position, while covering the entire area of an ink ejection portion of the nozzle. A belt, which can come into contact with the print head and is movable in the longitudinal direction of the print head, is provided at the ejection recovery position, and an opening is formed in this belt so as to correspond to some nozzles in the longitudinal direction of the print head, and air is sucked into the opening. The feature is that the means are connected in communication.

[0007]

According to the above characteristic structure, the line print head is switched to the discharge recovery position, and the air suction means is operated in a state where the belt is in contact with the ink discharge portion of the nozzle, thereby performing the line print. Of the nozzles on the head,
The ink is forcibly sucked only in a part of the nozzle group which faces the opening formed in the belt. Then, with the movement of the belt in which the opening is formed, the forcible suction range of the ink is sequentially moved in the longitudinal direction of the line print head, and finally the ink is forcibly sucked to all the nozzles of the line print head. Be seen.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a printing apparatus of an inkjet recording apparatus. In FIG. 1, reference numeral 1 denotes a platen roller horizontally mounted on a main body 2 of an apparatus, and a pinch roller 3 and a conveyance guide 4 are arranged on a peripheral portion thereof. Reference numeral 5 is a paper feed means for feeding the paper in the paper feed cassette 6 to the printing portion of the platen roller 1, and 7 is a paper discharge tray for stocking the paper after printing.

Reference numeral 8 is a line print head having a large number of nozzles 9 over the entire width of the print area. The print position P is a position where the nozzles 9 face the print part of the platen roller 1 and a position apart from the print position P. The ink ejection recovery position Q is provided so as to be movable. More specifically, the line print head 8 is provided on a fan gear 10 that is rotatable around an axis parallel to the rotation axis of the platen roller 1, and the fan gear 10 includes, for example, a pulse motor M. A directly connected pinion gear 11 is meshed with the pinion gear 11 and is configured to be driven and switched to the above two positions P and Q based on the position detection by the sensors 12 and 13.

Reference numeral 14 denotes an ejection recovery means for forcibly sucking the ink in the nozzle 9 to recover the ink ejection function of the nozzle 9, which is arranged at the ejection recovery position Q. Details of the ink discharge recovery means 14 are shown in FIGS. In these drawings, reference numeral 15 in the drawings is a cap configured to cover all the nozzles 9 of the print head 8 switched to the ejection recovery position Q all at once, which is movable up and down along the guide 16 and driven by the solenoid 17. When the print head 8 is moved between the two positions P and Q provided on the receiving member 18,
It is configured so that it can be switched to a lower retracted position so as not to interfere with the movement.

Reference numeral 19 denotes an endless belt which abuts the entire area of the ink ejection portion of the nozzle 9 with the cap 15 covering the nozzle 9, and a pair of rollers 20 axially supported on both sides in the longitudinal direction inside the cap 15. , 21 wound,
In addition, air vent holes a are formed on both sides in the width direction. Then, an opening 22 having a size corresponding to a part of the nozzles 9 in the longitudinal direction of the print head 8 is formed at a predetermined position of the belt 19, and one of the rollers 20 is controlled to reciprocate in a pulse. Motor M ₁ is installed in series,
With the reciprocal movement of the belt 19 caused by the rotation of the motor M _1, the opening 22 is exposed over the entire area of the nozzle 9.

Reference numeral 23 is an air suction pump (an example of suction means) to which a waste ink cartridge 24 is connected, and a waste ink suction line 25 is connected to the internal space of the cap 15 through the bottom of the receiving member 18. Reference numeral 26 is an ink cartridge for supplying ink to the print head 8, and 27 is an ink supply line extending from the ink cartridge 26 to the print head 8.

According to the above arrangement, for example, the print head 8 is switched to the ejection recovery position Q each time printing of one document is completed, and when the position switching state is detected by the sensor 13, the receiving member 18 is lifted. The nozzle group 9 of the print head 8 is covered with the cap 15, and the belt 19 abuts on the ink ejecting section of the nozzle group 9 except for a part of the nozzles 9 facing the opening 22. Drying and solidification of the ink in 9 is prevented.

When the ink ejection recovery mode for the group of nozzles 9 is set periodically or as needed, the print head 8 is switched to the ejection recovery position Q and the ink ejection from the nozzles 9 is performed as described above. Belt 1
The group of nozzles 9 of the print head 8 is covered with the cap 15 so as to bring the nozzles 9 into contact with each other. Here, the air suction pump 23 in the state of communication connection with the opening 22 is driven and the nozzle of the opening 22 The belt 19 is reciprocated over a predetermined range so as to face the entire area of the nine groups.

Thus, the belt 19 having the opening 22 formed therein.
When the air suction pump 23 is operated in a state in which the nozzle 9 is in contact with the ink discharge portion of the nozzle 9, the ink is targeted to only a part of the nozzles 9 of the line print head 8 facing the opening 22. Will be forcibly sucked. The form of this forced ink suction is similar to the forced suction of ink to the nozzles of a serial type print head with a small number of nozzles. Inside nozzle 9
In addition, the ink ejection function can be properly restored.
In addition, the capacity of the air suction pump 23 can be reduced as compared to the case where all the nozzles 9 are forcibly sucked with ink.

The belt 1 having the opening 22 is formed.
With the movement of 9, the proper forcible suction range of the ink is sequentially moved in the longitudinal direction of the line print head 8,
Eventually, forcible suction of the ink to the entire nozzle 9 is favorably performed, and as a result, the ink ejection function can be uniformly restored to all the nozzles 9 of the line print head 8. it can.

Since the waste ink suction line 25 connected to the air suction pump 23 is opened so as to face the lower side of the belt 19 around which the belt 19 is wound, the belt 19 portion serves as a resistance to the air suction. The air vent holes a are provided on both sides of the belt 19 in the width direction, but the air vent holes a are not necessarily provided, or the waste ink suction line 2 is provided.
It is also possible to open 5 on the side of the cap 15.

Further, although the belt 19 has an endless structure, as shown in FIG. 5, the motor M ₁ is directly connected to _one roller 20 and the other roller 21 has a belt rewinding function (not shown). Equipped with both rollers 20,
The belt 19 may be reciprocated by winding both ends of the belt 19 around the belt 21. In this case, the belt 1
Since 9 does not become a resistance for air suction, the degree of freedom of the opening position of the waste ink suction line 25 becomes high.

A second embodiment of the discharge recovery means 14 will be described below with reference to FIGS. The ejection recovery means 14 implemented here is characterized in that it has a cleaning function for the tip of the nozzle. Specifically, the belt 19 is made wide, and the entire width of the print head 8 is set in the width direction thereof. Nozzle 9
A cap 15 is formed to cover all at once, and on the other side in the width direction, an opening 22 having a size corresponding to a part of the nozzles 9 in the longitudinal direction of the print head 8 and a recess 28 continuous with the opening 22 are formed.
In addition, the waste ink suction line 25 is communicatively connected to the recess 28. Further, a concave portion 29 similar to the cap 15 is formed in the widthwise intermediate portion of the wide belt 19, and a large number of cleaning blades b which are easily bent and deformed in the moving direction of the belt 19 are raised at the bottom of the concave portion 29. It is connected.

On the other hand, the pinion 3 directly connected to the motor M ₂
A slide member 32 that is horizontally moved in the width direction of the belt 19 by 0 and the rack 31 is provided, and a vertical guide 33 is erected on the slide member 32, and a support member 34 in which the receiving member 18 is connected to the upper portion is provided. A vertical rack 35 is provided along the vertical guide 33 so as to be vertically movable, a vertical rack 35 is formed on one side of the support member 34, and a motor M ₃ having a pinion 36 meshing with the vertical rack 35 is directly connected to the slide member. 32, the receiving member 18 is vertically and horizontally movable.

Further, partial rollers 20 and 21 having a structure in which the cap 15 and the cleaning recess 29 can be freely wound around are provided on both sides of the receiving member 18 in the longitudinal direction.
The wide belt 19 is wound around the rollers 20 and 21, and the line print head 8 is switched to the ejection recovery position Q in response to ink ejection recovery and capping and cleaning mode selection. The member 18 is moved to a predetermined position in the width direction of the belt 19.

That is, in the ink ejection recovery mode, the opening 2
2 corresponds to the ink ejection portion of the nozzle 9, the cap 15 corresponds to the ink ejection portion of the nozzle 9 in the capping mode, and the blade b in the cleaning mode.
The receiving member 18 is moved in the width direction of the belt 19 so that the position corresponding to the ink discharge portion of the nozzle 9.

Following the movement of the belt 19, the receiving member 1
8 is lifted, the ink ejection portion is covered with the cap 15 in the capping mode, the belt 19 reciprocates in the cleaning mode, and the ink adhering to the ink ejection portion is scraped off by the blade b, for example, and the ink ejection recovery mode. Then, by driving an air suction pump (not shown) and reciprocating movement of the belt 19, the above-mentioned uniform ink ejection function is restored to all the nozzles 9 of the line print head 8.
It is done to.

In the second embodiment described above, the belt 19 is configured to move in the width direction according to the selection of the mode.
The line print head 8 can be moved in the width direction 9 of the embodiment. Further, although the cleaning blade b is erected on the bottom of the concave portion 29, the blade b may be erected on the surface of the belt 19 to limit the lifting amount of the receiving member 18 in the cleaning mode.

[0025]

As described above, according to the present invention, some of the nozzles of the line print head are targeted for ink ejection recovery, and in the same form as the forced suction of ink to the nozzles of the serial type print head. By recovering the ink ejection function of the nozzles and moving the ejection recovery range after doing so, even if the degree of clogging is different for each nozzle, the suction means With the capacity reduced, eventually the ink can be forcibly sucked into all the nozzles evenly and satisfactorily, and eventually the ink ejection function to all the nozzles of the line print head is evenly maintained. It has come to be possible to recover it evenly.

[Brief description of drawings]

FIG. 1 is a side view of a main part of an inkjet recording apparatus.

FIG. 2 is a vertical sectional side view of a discharge recovery unit.

FIG. 3 is a vertical sectional front view of a discharge recovery unit.

FIG. 4 is a perspective view of a belt in a discharge recovery unit.

FIG. 5 is a perspective view of another embodiment of the belt in the discharge recovery means.

FIG. 6 is a vertical sectional side view of a discharge recovery device according to a second embodiment.

FIG. 7 is a perspective view of a belt used in the discharge recovery means of the second embodiment.

[Explanation of symbols]

8 ... Line print head, 9 ... Nozzle, 19 ... Belt, 2
2 ... Opening, 23 ... Air suction means, P ... Printing position, Q ... Ejection recovery position.

Front page continuation (72) Inventor Setsuo Hori 1-22 Tamatsukuri Chuo-ku, Osaka City, Osaka Mita Industry Co., Ltd.

Claims (1)

[Claims] 1. A line print head having a large number of nozzles covering the entire width of a print area is provided movably between a print position and an ink discharge recovery position, and is capable of contacting the entire area of an ink discharge portion of the nozzle. Further, a belt movable in the longitudinal direction of the print head is provided at the ejection recovery position, an opening is formed in this belt so as to correspond to some nozzles in the longitudinal direction of the print head, and an air suction means is connected to the opening. An ink jet recording apparatus characterized by being provided.