JPH10323996A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To immediately and surely clean all of ink jet nozzles and to reduce a performance for negative pressure suction. SOLUTION: While a cleaning means 230 is conveyed in a direction of a width of a printing face M1, ink is sucked from multiple ink jet nozzles 207 arranged in the direction of the width by using a suction device 231. The suction device 231 does not contact the ink jet nozzles 207. A wiper capable of wiping the ink stuck to each of the ink jet nozzles 207 is provided at the cleaning means 230.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer having a print head comprising a number of ink jet nozzles arranged in the width direction of a printing surface.

[0002]

2. Description of the Related Art An ink jet printer prints characters, images, and the like by jetting (flying) ink from a fine ink jet nozzle equivalent to one dot. Is easy to cause clogging. In addition, ink or the like easily adheres to the nozzle tip (ejection port) and the vicinity thereof and is likely to be solidified.

Therefore, the inside of each ink jet nozzle is cleaned at an appropriate time, and the tip of each nozzle is wiped.

[0004] As a cleaning means, a pressure discharge method in which ink is applied by applying a higher pressure than usual to an ink pressure chamber common to each nozzle, and ink is suctioned from the tip of each nozzle using negative pressure. Although there is a negative pressure suction method, a negative pressure suction method is often employed.

[0005] The wiping means is formed so that a flexible wiper is pressed against the tip of each nozzle, and both are relatively moved in that state, so that the ink adhering to the tip of each nozzle can be wiped.

FIG. 5 shows a general inkjet printer.
As shown in the figure, a print head 500 that is integral with an ink tank (ink cassette) 513 and has an inkjet nozzle for one dot in the row direction (X) of the print medium M and a plurality of dots in the column direction using a reciprocating mechanism. And line direction (X)
Is printed by jetting ink while reciprocating over the entire length of the printer. Then, the print head 500 is moved in the row direction (X) of the print medium M to an appropriate time, and the print head 500 is moved out of the print area to an empty area. The ink is suctioned at a negative pressure. Further, the ink adhering to the tip of each nozzle (ejection port) and its vicinity is wiped by the wiping unit 540.

Here, the cleaning means 530
Is a suction tool 531 that moves in the column direction of the print medium M, contacts the orifice surface of the print head 500, and surrounds all the inkjet nozzle tips, and a suction pump 535 for generating a negative pressure in the suction tool 531. And formed so as to be able to suck ink from all the nozzles. If any of the cleaning means 530 or the print head 500 moves in the row direction during cleaning, the suction device 5
There is a risk that the nozzle 31 may come off from the tip of each nozzle, or the tip of the nozzle may be damaged due to an overload.

On the other hand, the wiper 541 is
0 in the row direction while being in elastic contact with each nozzle tip (for example, reciprocating the print head 500 in the row direction with the wiper 541 stopped) to wipe off the ink adhering to each nozzle tip. I do.

In the above-described serial type ink jet printer, since the number of ink jet nozzles is generally small, cleaning and wiping can be performed relatively easily.

By the way, the above-described conventional nozzle heads for each color are reciprocated along the entire length in the row direction, and printing is performed during each forward movement to print one row. After printing one row, a printing medium (plain paper, OHP) is printed. Paper), which can greatly increase the printing speed compared to a so-called serial type ink jet printer which repeats the above process by feeding M one line in the column direction and capable of continuous printing operation over many sheets, and a so-called laser printer. The present applicant has proposed an ink-jet printer that can achieve a significant reduction in size as compared with (for example, Japanese Patent Application No. Hei 8-29).
No. 6957).

That is, in FIG. 6, the drum 10 can rotate at a constant peripheral speed and can hold the print medium M on the outer peripheral surface 11 thereof. Rotation of this drum 10 (Y)
A nozzle head 200 for each color is disposed in the direction.
Therefore, the integrated nozzle head 200 for each color or the integrated nozzle head 200 for each color in which a plurality of nozzle unit elements are arranged in the row direction over the entire length in the row direction (perpendicular to the paper surface) is, for example, as much as the pitch between inkjet nozzles. Ink is sprayed from the inkjet nozzles 207 for each color onto the rotating print medium M while being reciprocated, and printing is performed in the row direction, and printing is performed in the column direction using the rotation of the drum 10 during the forward movement of the pitch between the inkjet nozzles. Can be. That is, since the row-direction printing and the column-direction printing can proceed at the same time, the printing speed can be significantly increased.

Further, since the nozzle unit 200 for each color and the ink tank (ink cassette) 213 for each color are disposed at a distance from each other via a tube, the nozzle head 200 for each color can be lightened and reciprocated in the row direction. The fact that the moving speed can be greatly increased also contributes to further increase in printing speed, and the ink tank (ink cassette) 21 for each color
Since the capacity of No. 3 can be greatly expanded, a continuous printing operation of, for example, 500 or more sheets can be performed.

In order to realize these, one side (right side in FIG. 6) of the drum 10 is provided with a feeding means 60 and a medium feeding means 9.
0, and on the other side (left side in FIG. 6), the medium peeling means 140, the medium discharge / conveyance means 160, and the direction switching means 190
Are provided.

The feeding means 60 can selectively feed the printing medium M one by one from one of the cassette feeding means 71 and the manual feeding means 61. The medium supply means 90 feeds the fed print medium M to the drum 1 at a predetermined timing.
Feed to the 0 side. The medium peeling means 140 peels the print medium M from the drum 10 after printing, and
0 discharges and transports the peeled print medium M leftward in FIG. The direction switching unit 190 selectively switches between the discharge tray 192 and the upper discharge tray 193.

In this way, since the feeding, supply, holding, printing, peeling, and discharging / conveying of the printing medium M can be continuously performed, multicolor printing of, for example, 20 sheets or more of A4 size can be performed in one minute.

[0016]

A number of ink jet nozzles 2 such as the ink jet printer of the prior proposal are used.
07 is arranged in the width direction of the printing surface, if the cleaning and wiping are performed by moving the print head (200) to an empty area in the row direction similarly to the above-described serial type ink jet printer, The size in the direction is greatly increased, and the size of the printer is increased. In addition, the preparation for cleaning and the like and the restoration thereof take a long time, and hinder high speed printing.

Therefore, for example, as shown in FIG. 7 schematically shown, the print head (200) is
Is retracted in the direction away from the drum 10 and the cap moving means 230P is operated to cover all the ink jet nozzles 207 with the suction tool 231P.
It is conceivable that the ink jet nozzle 207 is sucked from the respective ink jet nozzles 207 via the suction tool 231P and the suction tube 241 to be collected in the waste ink tank 245 by operating the nozzle 4.

However, with such a configuration, it is difficult to uniformly and uniformly cover one suction tool 231P over all the ink jet nozzles 207 that are long in the row direction due to the processing accuracy, mounting accuracy, and the like. Therefore, the suction pump 24
4 and the like must be large and the negative pressure suction capacity must be increased. In addition, since a large amount of ink is sucked from the ink jet nozzle 207 having a small resistance, that is, not clogged, the cleaning of the ink jet nozzle 207 that is likely to be actually clogged tends to be insufficient.

An object of the present invention is to provide a small-sized ink jet printer capable of quickly and surely maintaining all the ink jet nozzles and reducing the negative pressure suction ability.

[0020]

According to the present invention, when each of the ink jet nozzles is individually suctioned with a negative pressure, a negative pressure is suctioned compared with a conventional example in which all nozzle tips are hermetically covered with a suction tool and suction is performed under a negative pressure. Sufficient cleaning can be performed even if the suction capacity is significantly reduced. If the individual negative pressure suction is performed while moving the suction tool in the width direction of the printing surface, wiping can be performed at the same time using the moving force. Paying attention to this, the suction tool is moved in the width direction of the printing surface so as to be individually formed to be capable of suctioning the negative pressure, thereby forming the above-mentioned object.

According to a first aspect of the present invention, a large number of ink jet nozzles arranged in a width direction of a printing surface movable in a longitudinal direction jet ink onto a printing surface to form a printable surface, and the width is set to a non-printing time when printing is not performed. An ink jet printer provided with a cleaning means formed so as to be able to clean each ink jet nozzle while sucking ink from each ink jet nozzle using a suction tool while moving in the direction.

According to the invention, the cleaning means sucks the ink from each ink jet nozzle using the suction tool while moving in the width direction of the printing surface during non-printing. As described above, since the ink is suctioned from each of the ink-jet nozzles which are sequentially aligned with the negative pressure, the cleaning can be sufficiently performed even if the negative pressure suction capability is reduced. Then, the ink can be sufficiently sucked from the ink jet nozzle which may be clogged with the ink.

Therefore, all the ink jet nozzles can be quickly and reliably cleaned, and the vacuum suction can be performed.

According to a second aspect of the present invention, there is provided an ink jet printer wherein the suction tool is not in contact with each of the ink jet nozzles.

In the case of this invention, even if the cleaning means is moved by moving it in the width direction of the printing surface, the suction tool does not interfere with each nozzle, so that no overload acts on each nozzle. Therefore, the same effects as those of the first aspect of the invention can be achieved, and furthermore, it is possible to more reliably prevent each inkjet nozzle from being damaged by being overloaded.

An ink jet printer according to claim 3, wherein said cleaning means is provided with a wiper capable of wiping ink adhered to each ink jet nozzle while contacting said ink jet nozzle immediately after cleaning by said suction tool. It is.

In this case, by moving the cleaning means in the width direction of the printing surface, the inside of the ink jet nozzle can be cleaned, and the ink attached to the nozzle tip can be wiped off by the wiper. Therefore, in addition to the same effects as those of the first and second aspects of the present invention, the ink adhered to the nozzle tip can be wiped off simultaneously with the cleaning of the ink jet nozzle, and the ink jet nozzle can be more quickly cleaned.・ Can be wiped.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. This inkjet printer is shown in FIG.
As shown in FIG. 4, the basic structure is the same as that of the previously proposed ink jet printer, but a cleaning means 230 is provided which is movable in the width direction of the printing surface M1, and the cleaning means 230 is moved in the width direction. The ink is individually suctioned from each ink jet nozzle 207 of each color nozzle unit 200 so as to be negatively sucked.

The same components as those of the previously proposed ink jet printer (FIG. 6) are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

In this embodiment, the printing surface M1 is held on the outer peripheral surface of the rotating body (drum 10) and is movable in the longitudinal direction (the rotation direction (Y) of the drum 10).

The print head (nozzle unit 200 for each color) has a number of ink jet nozzles 207, and the ink jet nozzles 207 are arranged in the width direction of the print surface M1. Each inkjet nozzle 20
7, ink is jetted onto the print surface M1 of the print medium M held on the drum outer peripheral surface 11 so as to be printable.

The cleaning means 230 includes a suction tool 231
And a wiper 23 provided on the upper surface of the suction tool 231.
4, and a suction tool moving means 235 capable of moving the suction tool 231 in the row direction (X) of the printing surface M1. The suction tool 231 moves in the row direction during non-printing while sucking ink from the inkjet nozzle 207 for each color. Each nozzle 207 is formed so as to be able to be cleaned.

The suction tool 231 is formed of a main body 231D and a plurality of ink suction nozzles 231N radially arranged on the main body 231D in correspondence with the respective ink jet nozzles 207 of the nozzle unit 200 for each color. . Each ink suction nozzle 231N has a pipe 232
Through the negative pressure generating means 233 (the waste ink storage tank 23).
3T, a suction pump 233P) is connected.

Therefore, each ink suction nozzle 231
When the suction pump 233P is driven in a state where N is aligned with the tip of each ink jet nozzle 207, the ink in each ink jet nozzle 207 is discharged to the waste ink storage tank 233.
Collected in T. The suction device 231 has a wiper 2 that can wipe ink attached to the tip of each inkjet nozzle 207 while being in contact with the tip immediately after cleaning.
34 are provided.

The suction tool moving means 235 is shown in FIGS.
, A pair of guide members (guide rod 235G, guide bar 235B) and a pair of guide members (235G, 235B) disposed parallel to the rotation axis J1 of the drum 10.
Support member 235 whose both ends are movably supported by
S, and a belt transmission mechanism 235D that can move and drive the suction tool support member 235S. The suction tool 231 attached to the suction tool support member 235S can
1N is formed so as to be able to face the tip of each color inkjet nozzle 207 in a non-contact state. That is, the relative position of each ink suction nozzle 231N and each color inkjet nozzle 207 is adjusted so that a minute gap G is formed between them.

Next, the operation of this embodiment will be described. When cleaning and wiping each inkjet nozzle 207 during non-printing, the cleaning means 2
The ink 30 is individually suctioned from each inkjet nozzle 207 using the suction tool 231 while moving in the width direction (X) of the printing surface M1. At this time, since the suction tool 231 is not in contact with each inkjet nozzle 207, it is possible to prevent an overload from being applied to each inkjet nozzle 207.

As described above, since the ink is suctioned from each ink jet nozzle 207 under a negative pressure, all the nozzles 207 are sucked.
Need not be hermetically sealed with the suction tool 232, and sufficient cleaning can be performed even if the negative pressure suction capacity is reduced. Then, the ink can be sufficiently sucked from the ink jet nozzle 207 which may be clogged with the ink. At this time, the ink adhering to the tip of each nozzle 207 due to the movement of the cleaning means 230 also removes the wiper 234.
Can be dispelled by. Therefore, the ink adhered to the tip of the nozzle 207 can be wiped off simultaneously with the cleaning of the inside of the inkjet nozzle 207.

According to this embodiment, the cleaning means 230 which is movable in the width direction of the printing surface M1 is provided, and the ink is individually transmitted from the ink jet nozzles 207 which are sequentially aligned while moving the cleaning means 230 in the width direction. Is formed so as to be capable of negative pressure suction, so that sufficient cleaning can be performed even if the negative pressure suction capability is reduced. Then, the ink can be sufficiently sucked from the ink jet nozzle 207 which may be clogged with the ink. Therefore, all the inkjet nozzles 207 can be quickly and reliably cleaned, and the negative pressure suction ability can be reduced.

Since the suction tool 231 is not in contact with each of the ink jet nozzles 207,
The nozzles 207 can be more reliably prevented from being damaged by being overloaded without interfering with the suction tool 231.

Since the cleaning means 230 is provided with a wiper 234 capable of wiping the ink adhered to each ink jet nozzle 207, the ink adhered to the tip of the nozzle 207 is also wiped simultaneously with the cleaning inside the ink jet nozzle 207. Therefore, all the inkjet nozzles 207 can be cleaned and wiped more quickly.

[0041]

According to the first aspect of the present invention, ink is sucked from a number of ink jet nozzles arranged in the width direction using a suction tool while moving the cleaning means in the width direction of the printing surface. There is no need to hermetically cover with a suction tool, and it is not necessary to increase the negative pressure suction capability. Then, the ink can be sufficiently sucked from the ink jet nozzle which may be clogged with the ink.

Therefore, all the ink jet nozzles can be quickly and reliably cleaned, and the negative pressure suction ability can be reduced. Further, downsizing can be achieved.

According to the second aspect of the present invention, since the suction tool is not in contact with each of the ink jet nozzles, the first aspect of the present invention has the following features.
In addition to achieving the same effects as in the case of the invention, it is possible to prevent each nozzle from overloading without interfering with the suction tool.

According to the third aspect of the present invention, since the cleaning means is provided with the wiper capable of wiping the ink adhered to each ink jet nozzle, the same effects as those of the first and second aspects of the invention can be obtained. In addition, the ink adhered to the nozzle tip can be wiped off simultaneously with the cleaning of the ink jet nozzle, and the ink jet nozzle can be more quickly cleaned.

[Brief description of the drawings]

FIG. 1 is a diagram for describing an embodiment of the present invention.

FIG. 2 is a view for explaining a cleaning unit.

FIG. 3 is a view for explaining a positional relationship between a cleaning unit and each ink jet nozzle.

FIG. 4 is a diagram for explaining the overall configuration.

FIG. 5 is a diagram for explaining a conventional example of a cleaning unit of a serial type ink jet printer.

FIG. 6 is a diagram for explaining a previously proposed inkjet printer.

FIG. 7 is a view for explaining an example of a cleaning unit.

[Explanation of symbols]

 Reference Signs List 10 drum (rotating body) 11 outer peripheral surface 200 nozzle unit for each color 207 inkjet nozzle 210 head support member 230 cleaning means 231 suction tool 234 wiper 235 suction tool moving means

Claims (3)

[Claims] An ink jet is jetted from a number of ink jet nozzles arranged in a width direction of a printing surface movable in a longitudinal direction onto a printing surface so as to be printable, and is moved in the width direction during non-printing. An ink jet printer provided with cleaning means formed so as to be able to clean each ink jet nozzle while sucking ink from each ink jet nozzle using a suction tool. 2. The ink jet printer according to claim 1, wherein the suction tool is not in contact with each of the ink jet nozzles. 3. A cleaning device according to claim 1, wherein said cleaning means is provided with a wiper capable of wiping ink adhered to each of said ink jet nozzles while being in contact with said ink jet nozzle immediately after cleaning by said suction tool. The inkjet printer described in 1.