JPS6213350A - Multi-nozzle ink jet printer - Google Patents

Abstract

PURPOSE:To remove bubbles selectively only from the nozzle head in which bubbles are generated, by making an ink recovery part absorb excessive ink to be generated by the operation of purging. CONSTITUTION:The valve 105 inside a pump chamber 104 is lowered in the arrowed D direction and the inside of a pipe 102 and an ink recovery part 30 are made of negative pressure. Ink 21 is sucked from a nozzle pipe 11, a tube 13, and a filter 14 by this negative pressure and the generated bubbles are removed. The sucked ink is absorbed from a connecting pipe 34 with an ink-absorbing material 31 to be recovered, which is not reliesed outside. When ink particles 6 are not jetted from a nozzle head 1m, a carrier base 2 is moved and the purge of the nozzle head 1m is carried out by advancing the purge mechanism part 100 as shown by the dotted line. Because there is no ink on and after the pipe 102 of the purge mechanism part 100 by the recovery with the ink absorption material, through different nozzle heads are purged with one piece of purge mechanism, there is neither the mixing color nor the reflux of ink.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a multi-nozzle inkjet printer, and particularly to an on-demand multi-nozzle inkjet printer that records by ejecting ink particles only during recording.

[・♀Ming background]

On-demand inkjet printers record and reproduce information by changing the ink chamber volume of a nozzle head using an information signal and ejecting ink particles from nozzle holes. There is no need for a special ink pressure pump for ejecting ink particles, and there is an advantage that a printer with a simple structure can be realized.

For example, it is easy to use multiple colors by preparing nozzle heads for cyan, magenta, yellow, and black ink. If multiple nozzle heads of the same color are used, the speed can be increased.

However, this type of printer requires a bubble removal mechanism (referred to as a purge mechanism) because if bubbles occur in the nozzles, ink particles will not be ejected and recording will not be possible.

For example, Japanese Patent Application Laid-Open No. 58-62058 proposes a purge mechanism consisting of a cap, a connecting tube, and a suction pump, in which all the nozzle heads are simultaneously suctioned with negative pressure by the suction pump to remove the air bubbles. There is.

Based on conventional experience, in this type of multi-nozzle inkjet printer, it is rare for air bubbles to occur in all nozzle heads at the same time, resulting in an inability to record. Therefore, the purge operation is not necessary for those that operate well, and it is better not to perform the purge operation for them in order to prevent ink wastage.

In the conventional example, the purge mechanisms of all nozzle heads were operated at the same time, so a suction pump was required to prevent the sucked ink from mixing with each other. As a result, ink is wasted, the apparatus is complicated, and it is necessary to take measures against ink contamination of the equipment due to discharge of unnecessary ink to the outside.

[Purpose of the invention]

The purpose of the present invention is to selectively remove air bubbles from only those nozzle heads that require purge operations, thereby reducing waste of ink.

It is an object of the present invention to provide a multi-nozzle inkjet printer that eliminates the need for measures against ink contamination. Along with the structure,
A connecting pipe is provided to suck the excess ink that comes out during the purge operation from the orifice at the tip of the nozzle to the ink recovery unit to prevent contamination due to leakage of excess ink.Furthermore, one purge mechanism is shared by multiple nozzle heads, eliminating air bubbles. It is designed so that it can be attached and detached only to the nozzle head where the purge operation is performed.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a schematic diagram of the configuration of a multi-nozzle inkjet printer, in which a color inkjet printer includes nozzle heads lc, 1m, ly, and lb for cyan, magenta, yellow, and black ink, and stoppers 3c and 3m are mounted on a carrier base 2.

3)'+3b, individually fixed.

The carrier base 2 is movable in left and right directions A and B with respect to the recording medium 7 on rails 4 and 5. ,6
e * 6 m p 6 y + 6 b are ink particles ejected from the nozzle heads lc, 1 m, 1)'+ lb, respectively, and an image 8e is printed on the recording medium 7 being transported in the direction of arrow C.
, 8m, 8y, 8b.

FIG. 1 is a diagram showing one configuration of a nozzle head according to the present invention, in which each color has the same shape. Nozzle 10, ink tank 20. It has an integrated structure in which the ink recovery section 30 is organically arranged.

nozzle], 0 is nozzle pipe 11. Electromechanical transducer element, for example a piezoelectric element 12. Tube 13. It consists of a filter 14 and the like, and a minute orifice 15 is formed at the tip of the nozzle pipe 11. The piezoelectric element 12 has a cylindrical shape, is fixed to the nozzle pipe]1, and is connected to a conductive wire 16. An information signal 9 is applied via electrode 17 .

The ink tank 20 is arranged diagonally at the bottom in the opposite direction to the orifice 15, is filled with ink 21, and is connected to the filter 14. Ink 21 is supplied to the nozzle pipe 11 through a tube 13.

The ink recovery section 30 is arranged below the nozzle 10, and contains, for example, a porous absorbent body 31 therein. The suction pipe 32 communicates with the outside air. A conduit 33 connects the ink tank 20 and the ink recovery section 30, and a valve 22 is provided on the ink tank side.

The connecting pipe 34 communicates the ink recovery section 30 with the recess a (FIG. 3) of the nozzle head 1, and a valve 35 is provided on the ink recovery section 30 side.

Now, when the information signal 9 is applied to the piezoelectric element 12 of the nozzle 10, the volume of the nozzle pipe 11 contracts and the ink particles 6 are ejected. However, if air bubbles are generated in the nozzle vibrator 1, the ink particles 6 will not be ejected, making it impossible to record an image, so it is necessary to remove these air bubbles.

FIG. 3 is a diagram illustrating a purge operation for removing the bubbles. The main parts of the nozzle head 1 are also shown, and the same parts as the first one are given the same numbers, so the explanation thereof will be omitted.

100 is a purge mechanism section, and a cap 101 is.

The concave portion a of the nozzle head 1 is covered to block the orifice 15 and the connecting pipe 34 from the outside air. Furthermore, the cap 101 is
The suction pipe 32 of the ink recovery section 30 is also covered. The suction pipe 32 of the ink collection section already mentioned is the pipe 102.
It is guided to the suction pump 103 through. A feature of the present invention is that this t<-shi mechanism is removable from the nozzle head and is shared between a plurality of nozzles.

When the purge mechanism is in operation, when the valve 105 in the pump chamber 104 is lowered in the direction of the arrow by a device (not shown), negative pressure is created in the pipe 102 and the ink recovery section 30, and the valve 35 changes from the dotted line to the solid line. , and further the valve 22 in FIG.
stops conduit 33.

Then, the recess a of the nozzle head 1 also becomes negative pressure, and the nozzle pipes 1.1. Tube 13. The ink 21 is sucked through the filter 14, and air bubbles generated in the nozzle pipe 11 are removed. here.

The ink sucked from the nozzle pipe 11 is transferred to the connecting pipe 34.
The ink is collected by suction through the ink suction body 31 of the ink collection unit 30, and does not leak to the outside.

When the purge operation is completed, the cap 101 is removed from the recess a of the nozzle head and the suction pipe 32 of the ink recovery section 30 by a return mechanism (not shown), and the valve 105 in the pump chamber 104 returns in the direction of the dotted arrow E, returning to the initial state. become a state.

The ink collected once here soaks into the ink absorber 31 and does not flow into the pipe 102 or the pump 104, so when the purge operation is completed, unlike the conventional method, the ink is removed from the pump chamber 104. Ink does not reach the nozzle pipe 11 through the pipe 102 due to backflow or capillary phenomenon.

FIG. 4 shows an example of applying this purge mechanism to a color inkjet printer, the second nozzle head 1c,
1m, 1. , y, 1b viewed from above.

In the figure, 1, for example, a magenta ink nozzle head of 1 m.
When the ink particles 6 are not ejected, the purge am section 10
The carrier base 2 moves to the front of
Perform a purge operation.

Here, as mentioned above, the pipe of the purge mechanism section 100]
Since ink does not flow after 02, even if one purge mechanism performs purging operations for nozzle heads of different colors, there will be no color mixing or backflow of ink.

In this embodiment, a color printer using different inks in the nozzle heads has been described, but it goes without saying that the present invention can also be applied to a multi-nozzle inkjet printer that uses a plurality of nozzle heads of the same color ink to increase speed.

〔Effect of the invention〕

In the present invention, the nozzle of the nozzle head, the ink tank, and the ink collection section are organically arranged to form an integrated structure, and the ink sucked during the purge operation can also be collected and processed in the ink collection section, which was not necessary in the past. This eliminates the need for a special recovered ink processing device, and prevents ink contamination of equipment.

Furthermore, since the collected ink does not flow into the suction pump chamber of the purge mechanism, there is no ink backflow or color mixing even if you purge different color nozzle heads, and a single purge mechanism can handle multiple color nozzle heads. Bird operation is now possible,
It is only necessary to target the nozzle head where bubbles occur and actually require a purge operation, so there is no ink wastage as in the past.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the internal structure of a nozzle head of a multi-nozzle inkjet printer according to the present invention, FIG. 2 is a schematic view of the head section of the multi-nozzle inkjet printer, and FIG. FIG. 4 is an explanatory diagram of the operation of removing air bubbles from multiple nozzles using one purge mechanism. 1... Nozzle head, 10... Nozzle, 11...
Nozzle vibe, 12... Piezoelectric element-j, x5... Orifice, 20... Ink tank, 21... Ink,
3o... Ink collection section, 31... Ink absorber, 3
2... Suction pipe, 34... Connecting pipe, 100...
Purge mechanism section, 1o1...cap, 103...suction pump, 1o4...pump chamber, 105...valve.

Claims (1)

[Claims] 1. A nozzle that ejects ink particles in response to an electric signal applied to an electromechanical transducer mounted around the nozzle, an ink tank that supplies ink to the nozzle, and a nozzle that is used to remove air bubbles from the nozzle. In a multi-nozzle inkjet printer equipped with a required number of nozzle heads consisting of an ink collection section for collecting excess ink discharged from the orifice and a purge mechanism for removing air bubbles from the orifice of the nozzle, the ink collection section is provided at the bottom of the nozzle, It forms a communication path that guides excess ink leaked from the nozzle orifice when removing air bubbles to the ink recovery section, while also sharing one purge mechanism with multiple nozzle heads and attaching and detaching it only to the nozzle head where air bubbles have occurred. A multi-nozzle inkjet printer that eliminates air bubbles. 2. The multi-nozzle inkjet printer according to claim 1, characterized in that at least one of the nozzle head and the purge mechanism in which air bubbles are generated and malfunctions is moved so that they face each other to remove air bubbles.