JPH09109397A - Bubble ink jet system and bubble ink jet printer equipped with the system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the spread of ink per dot to an object of printing changeable by changing ink discharge power. SOLUTION: A nozzle 11 which includes an ink accumulation space 12 and an ink outlet 13 leading from the ink accumulation space 12 to an outside space is formed, an ultrasonic wave vibrator 17 which gives an ultrasonic wave vibration of an amplitude and a frequency which can generate bubbles in ink 1 in the ink accumulating space 12. The size of a bubble 2 generated in the ink 1 is changed and the ink discharge power is changed by changing the amplitude and/or frequency of the ultrasonic wave vibrator 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bubble ink jet apparatus for generating bubbles in ink and ejecting the ink by pressure fluctuation caused thereby, and a bubble ink jet printer provided with the same.

[0002]

2. Description of the Related Art As a conventional bubble inkjet printer, for example, there is one shown in FIG. This bubble inkjet printer has a heater 4 on the inner peripheral surface of the nozzle 3.
Is provided, the ink 1 in the nozzle is partially heated by the heater 4, bubbles 2 are generated in the ink, and the ink 1 is ejected by the pressure fluctuation caused thereby.

[0003]

However, in such a conventional technique, the ink 1 is heated and the ink 1 is heated.
Since the temperature of is set to the boiling point and the bubble 2 is generated,
If the electric power applied to the heater 4 is increased, the amount of bubbles generated increases and the ink ejection amount can be increased or decreased to some extent, but the ejection force of the ink 1 cannot be changed. Therefore, the conventional technique has a problem in that it is not possible to change the spread of ink per dot on the print target S, and the degree of freedom in print expression is limited. Further, since the distance between the nozzle 3 and the print target S cannot be widened, the print target S may be contaminated with the ink adhering to the nozzle 3.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to change the spread of ink per dot and to prevent the print object from being contaminated with ink. It is an object of the present invention to provide a bubble inkjet device capable of performing the same and a bubble inkjet printer including the same.

[0005]

In order to achieve the above object, an ink reservoir space (12, 12a) into which ink (1) is supplied is formed and the ink reservoir space (12, 12a) is formed. Nozzle (11, 1) in which a discharge port (13, 13a) connecting from 12a) to the external space is formed.
1a) and ultrasonic vibration that gives the ink (1) an ultrasonic vibration of an amplitude and a frequency capable of generating a bubble (2) in the ink (1) supplied to the ink reservoir space (12, 12a). Means (17, 40, 41) are provided.

Here, it is preferable that the ultrasonic vibration means has ultrasonic vibration changing means (40, 41) for changing the amplitude and / or the frequency of the ultrasonic vibration.

Further, in the bubble ink jet device, the ink reservoir space (12a) of the nozzle (11a).
Is the target ink ejection direction (I) from the ejection port (13a).
The ultrasonic vibrating means (17) extends in a direction perpendicular to the direction in which the ink reservoir space (12a) extends, and the ultrasonic vibrating means (17) extends vertically to the ink (1) in the ink reservoir space (12a). It may give vibration. In this case, the ultrasonic vibration means (17) is installed in the nozzle (11a) in a direction parallel to the direction in which the ink reservoir space (12a) extends.
It is preferable to include a bubble generation position changing means (50) for moving along.

A bubble ink jet printer for achieving the above object is a bubble ink jet device described above, and ink reservoir spaces (12, 12a) of nozzles (11, 11a) in the bubble ink jet device.
Ink supply means (14, 1) for supplying ink (1) into the inside
5, 16) and the printing target (S) to which the ink (1) ejected from the nozzles (11, 11a) is applied,
A moving mechanism (2) for relatively moving the nozzles (11, 11a)
0, 30) are provided.

In the above, the symbols in parentheses are
It is the code of the corresponding part of the embodiment described below.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various bubble inkjet printers as embodiments according to the present invention will be described below with reference to FIGS.
This will be described with reference to FIG.

First, a bubble ink jet printer as an embodiment according to the present invention will be described with reference to FIG. This bubble inkjet printer uses ink 1
Head 10 for ejecting the ink toward the printing paper S
And a head moving mechanism 20 for moving the head 10.
And a sheet feeding mechanism 30 for moving the printing sheet S, and an ultrasonic transducer 17 incorporated in the printer head 10.
Oscillator 41 that vibrates the printer head 10
A control valve drive circuit 42 that drives the ink control valve 15 incorporated therein, a head movement drive circuit 43 that drives the head movement mechanism 20, a paper feed drive circuit 44 that drives the paper feed mechanism 30, an oscillator 41, and these. Control unit 40 for controlling the drive circuits 42, 43, 44 of the
And

As shown in FIG. 1, the printer head 10 has an ink tank 14 for storing the ink 1, a nozzle 11 for ejecting the ink 1 supplied from the ink tank 14, and a nozzle 11 for supplying the ink 1 from the ink tank 14. It has an ink control valve 15 for limiting the ink 1, and an ultrasonic vibrator 17 for vibrating the ink 1 in the nozzle 11 to generate bubbles 2 in the ink.

The nozzle 11 is formed with an ink reservoir space 12 extending in a fixed direction, and from the ink reservoir space 12 to the external space, in a direction perpendicular to the direction in which the ink reservoir space 12 extends. Ink ejection port 1 which penetrates
3 are formed. The ultrasonic transducer 17 described above is provided at a position of the nozzle 11 facing the ink ejection port 13. The vibrator 17 is an electrostrictive vibration element made of PZT (zirconate titanate). An oscillator 41 for applying an AC voltage to the ultrasonic transducer 17 is connected to the ultrasonic transducer 17. An ink line 16 extending from the ink tank 14 is connected to the ink reservoir space 12. The ink control valve 15 is provided in the ink line 16. The ink control valve 15 is connected to a control valve drive circuit 42, and is driven by a drive signal from this circuit 42.

The head moving mechanism 20 has an ink ejection direction I.
A lead screw 21 extending in a direction perpendicular to (a direction perpendicular to the direction in which the ink reservoir space 12 extends) and a head moving motor 22 for rotating the lead screw 21.
And a coupling 23 that connects the head moving motor 22 and the lead screw 21 and a nut 24 that is screwed onto the lead screw 21 and fixed to the head 10. The head movement motor 22 is connected to a head movement drive circuit 43 and is driven by a drive signal from this circuit 43.

The paper feed mechanism 30 is a device for feeding the paper S in a direction perpendicular to the ink ejection direction I and the head movement direction H, and a drive shaft 31 extending in a direction parallel to the lead screw 21 of the head movement mechanism 20. , A plurality of drive rollers 32, 32, ...
, A plurality of driven rollers 33, 33 arranged so as to face the drive rollers 32, 32, ..., A paper feed motor 34 for rotating the drive shaft 31, and a rotational force of the motor 34. 31 and a plurality of gears 35, 35 for transmitting to 31. The paper feed motor 34 is connected to a paper feed drive circuit 44 and driven by a drive signal from this circuit 44.

Next, the operation of the bubble ink jet printer described above will be described. At the time of printing, the head movement drive circuit 43 receiving the control signal from the control unit 40 drives the head movement motor 22, and the paper feed drive circuit 44 drives the paper feed motor 34. When the head moving motor 22 is driven, the lead screw screw 21 rotates, and the nut 24 and the head 10 move by the rotation amount of the lead screw screw 21. Also,
When the paper feed motor 34 is driven, the drive shaft 3
, Rotate with 1, and the sheet S sandwiched between the drive rollers 32, 32, ... And the driven rollers 33, 33 ,. With the above series of operations,
The relative positional relationship between the head 10 and the paper S changes.

Further, the control valve 1 in the printer head 10
5 opens, the ink 1 starts to be supplied from the ink tank 14 to the ink reservoir space 12 in the nozzle 11, and the oscillator 41 that receives the control signal from the control unit 40 drives to cause the ink to be transmitted from the ultrasonic transducer 17. Longitudinal vibration is radiated for 1. At this time, the vibration frequency of the vibrator 17 is about 1.8 MHz and the vibration amplitude is about 0.05 μm. The ink 1 in contact with the vibration radiating end surface of the ultrasonic oscillator 17 is temporarily subjected to a strong acceleration due to this longitudinal vibration to temporarily become negative pressure, and bubbles 2 are generated in the ink 1. . When the bubble 2 bursts, a strong pressure is generated again. This pressure pushes the ink 1 and the ink 1 is ejected from the open portion, that is, the ink ejection port 13.

If an instruction to change the spread of ink per dot is given to the control unit 40 in advance,
During printing, the oscillator 4 is instructed by an instruction from the control unit 40.
The output from 1 to the vibrator 17 changes, and the vibration amplitude of the vibrator 17 changes. When the vibration amplitude of the vibrator 17 changes, the acceleration applied to the ink 1 also changes, so the size of the bubble 2 also changes and the pressure fluctuation width in the ink reservoir space 12 of the nozzle 11 also changes. As a result, the ink ejection force is changed, and the spread of ink per dot on the printing paper S can be changed, and the degree of freedom of printing expression can be increased. Although the vibration amplitude of the vibrator 17 is changed in this embodiment, the vibration frequency of the vibrator 17 may be changed to change the spread of the ink per dot. Further, since the ink ejection force can be increased, the distance between the nozzle 11 and the printing paper S can be widened, and the printing paper S can be prevented from being contaminated by the ink attached to the tip of the nozzle 11. .

Further, in the embodiment of the present invention, unlike the wire dot printer or the thermal transfer printer, the head does not move while contacting the paper, so that not only high speed printing is possible but also noise at the time of printing. Can be kept very small.

Next, a printer head of another bubble ink jet printer as one embodiment according to the present invention will be described with reference to FIG. This printer head 10
a is different from the printer head 10 described above in that the Langevin type vibrator is used as the ultrasonic vibrator 17a and the ink discharge port 13a is provided in the direction in which the ink reservoir space 12a extends. ing.

The ultrasonic vibrator 17 of the printer head 10 described above uses the electrostrictive vibrating element as it is as a vibrator. The ultrasonic vibrator 17a of the printer head 10a is as described above. This is a Langevin type vibrator, in which a piezoelectric ceramic plate is used as a vibrating element, and metal plates are attached to both sides of this vibrating element. This vibrator 1
An amplitude amplification horn 18 is attached to the vibration radiation end face of 7a. This amplitude amplification horn 18 is
The vibration amplitude is expanded 2-3 times. The ultrasonic oscillator 17a is connected to an oscillator 41 that applies an alternating voltage to the ultrasonic oscillator 17a to oscillate it. This oscillator 41 includes a vibrator 1
An AC voltage having a vibration frequency substantially the same as the natural frequency of the vibration system constituted by 7a and the amplitude amplification horn 18 is output.

The above printer head 1 is attached to the nozzle 11a.
Similar to that of No. 0, an ink pool space 12a extending in a fixed direction is formed. This printer head 10a
From one end of the ink reservoir space 10a to the outside space,
An ink ejection port 13a is formed which penetrates in the direction in which the ink reservoir space 12a extends. An ink line (not shown) connected to an ink tank (not shown) is connected to the other end of the printer head 10a.

On the outer peripheral surface of the nozzle 11a, the vibration radiating surface 18 of the amplitude expanding horn 18 is arranged so that its vibration transmitting direction is perpendicular to the extending direction of the ink reservoir space 12a.
a is in contact. That is, the ultrasonic vibrator 1 is arranged so that the amplitude direction of the vertical vibration generated by the ultrasonic vibrator 17a is perpendicular to the direction in which the ink pool space 12a extends.
7a is in contact with the nozzle 11a via the amplitude expansion horn 18.

The ultrasonic transducer 17a is supported by the bubble generation position changing mechanism 50. The bubble generation position changing mechanism 50 includes a vibrator holding tool 51 for holding the vibrator 17a.
And a nut 52 fixed to the vibrator gripper 51
And a lead screw screw 53 which is screwed into the nut 52 and is parallel to the direction in which the ink reservoir space 12a extends.

When an AC voltage is applied to the ultrasonic transducer 17a and a bubble 2 is generated in the ink 1, this bubble 2
Ink 1 is ejected from the ink ejection port 13a due to the pressure fluctuation in the ink reservoir space 12a due to the generation of the ink. However, in this embodiment, since the ink ejection port 13a is formed in the direction in which the ink reservoir space 12a extends,
The ink ejection direction I coincides with the direction in which the ink reservoir space 12a extends. In other words, the ink ejection direction I is the direction opposite to the direction in which the ink reservoir space 12a extends, using the ink ejection port 13a as a reference.

As described above, also in this embodiment,
Since bubbles are generated in the ink by ultrasonic vibration as in the previous embodiment, basically the same effect as in the previous embodiment can be obtained.

By the way, in this embodiment, when one bubble 2 is generated, the ink 1 existing between the bubble generation position and the ink ejection port 13a is ejected. Therefore, the bubble generation position and the ink ejection port 13
It is possible to change the ink ejection amount by changing the distance to a. Therefore, in this embodiment, the bubble generation position changing mechanism 50 is provided to change the bubble generation position with respect to the ink ejection port 13a, thereby changing the ink ejection amount. In addition, this embodiment is
Lead screw 5 of bubble generation position changing mechanism 50
3 is rotated manually to change the bubble generation position. This lead screw screw 53 is connected to a motor so that the bubble generation position can be automatically changed by an instruction from a control unit or the like. May be.

Further, although this embodiment is an embodiment of a printer head, by providing the printer head 10a with the head moving mechanism 20 and the paper feeding mechanism 30 in the bubble ink jet printer of the above-mentioned embodiment, It goes without saying that a bubble inkjet printer can be constructed. Further, each of the printer heads 10 and 10a in the above embodiments has one nozzle, but the present invention is not limited to this, and a plurality of nozzles are two-dimensionally arranged vertically and horizontally. The printer head may be the one that is arranged as desired.

[0029]

According to the present invention, since the ink ejection force can be changed by changing the amplitude and / or the frequency of ultrasonic vibration, it is possible to change the spread of ink per dot on the printing object. You can Further, since the ink ejection force can be increased, the distance between the nozzle and the print target can be widened, and the print target can be prevented from being contaminated by the ink attached to the tip of the nozzle.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a bubble inkjet printer according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of another bubble inkjet printer head as one embodiment according to the present invention.

FIG. 3 is an explanatory diagram showing a configuration of a conventional bubble inkjet printer head.

[Explanation of symbols]

1 ... Ink, 2 ... Bubble, 10, 10a ... Printer head, 11, 11a ... Nozzle, 12, 12a ... Ink reservoir space, 13, 13a ... Ink ejection port, 14 ... Ink tank, 15 ... Ink control valve, 17, 17a ... Ultrasonic transducer, 18 ... Amplitude amplification horn, 20 ... Head moving mechanism, 3
0 ... Paper feed mechanism, 40 ... Control unit, 41 ... Oscillator, 42 ... Control valve drive circuit, 43 ... Head movement drive circuit, 44 ... Paper feed drive circuit, 50 ... Bubble generation position changing mechanism.

Claims (5)

[Claims] 1. A bubble ink jet apparatus for generating a bubble in the ink and ejecting the ink to the outside by a pressure fluctuation caused by the generation of the bubble, wherein an ink reservoir space to which the ink is supplied is formed, and A nozzle having an ejection port connected to the outside from the ink storage space, and a supersonic wave which gives ultrasonic vibration of an amplitude and a frequency capable of generating bubbles in the ink supplied to the ink storage space. A bubble ink jet device comprising: a sound wave vibrating unit; 2. The bubble inkjet apparatus according to claim 1, wherein the ultrasonic vibration means has ultrasonic vibration changing means for changing the amplitude and / or the frequency of the ultrasonic vibration. Bubble inkjet device. 3. The bubble ink jet apparatus according to claim 1, wherein an ink reservoir space of the nozzle extends from the ejection port in a direction opposite to a target ink ejection direction, and the ultrasonic vibration means includes the ink reservoir. A bubble ink jet device, wherein longitudinal vibration is applied to ink in the ink reservoir space in a direction perpendicular to a direction in which the space extends. 4. The bubble inkjet apparatus according to claim 3, wherein the ink reservoir space extends in a direction parallel to the extending direction.
A bubble ink jet apparatus comprising bubble generation position changing means for moving the ultrasonic vibrating means along the nozzle. 5. A bubble ink jet apparatus according to claim 1, 2, 3 or 4, ink supply means for supplying the ink into the ink reservoir space of the nozzle, and the ink jetted from the nozzle And a moving mechanism that moves the nozzle relative to a print target.