JPH04189548A - Ink jet head cleaning method - Google Patents

Abstract

PURPOSE:To remove entirely sticking matters stuck to an outlet and around thereof by ejecting water having supersonic wave vibration to the outlet of an ink jet head punched by application of laser beam having short wave length and around thereof. CONSTITUTION:Supersonic wave vibration is applied to a pure water 44 supplied to the inside of a cleaning head 40 by a supersonic wave vibrator 41 so that a cavity is generated. The pure water 44 is ejected to each outlet punched by excimer laser beam of a work 1 and a wall of an ink passage around the outlet, so that sticking matters stuck to the outlet and the wall of the ink passage around thereof are removed by the impact which occurs when the cavity vanishes. The removed sticking matters flow away from the outlet and the wall of the ink passage around thereof together with the ejected pure water 44. As a result, by using an ink jet head consisting of the work 1 for recording, a fill-in at the outlet, which occurs when the sticking matters are peeled from the wall of the ink passage so as to clog the outlet during repetition of discharge of the ink, can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cleaning treatment method for an inkjet head that performs recording on a recording medium by ejecting ink from an ejection port.

[Prior Art 1] First, an inkjet head that performs recording on a recording medium by ejecting ink from an ejection port will be described.

The ejection ports through which ink is ejected are open to the ejection port surface formed in the inkjet head, and the ink channels communicating with the ejection ports are formed on the back side of the ejection port surface. The ink passes through the ink flow path and is ejected from the discharge port toward the recording medium.

The ejection port is perforated by irradiating a short wavelength laser beam onto the back surface of the ejection port surface of the inkjet head in which the rough ink flow path is formed, and the ejection port that is perforated by the laser beam is formed. is the inner diameter (inner width if the aperture shape is rectangular) as it advances in the laser beam irradiation direction)
Finished in a shape that gradually becomes smaller □. The shape of the ejection opening is such that the inner diameter or inner width gradually increases like a trumpet as it advances in the ink ejection direction.

The direction of irradiation of the laser beam should be the same as the direction of ink discharge, since the ink discharge performance will deteriorate.

The part irradiated with laser light when drilling the discharge port is
The interatomic bonds are broken by the energy of the laser beam and the gas is released into the air, and a portion of this gas sticks to the wall of the ink flow path in the ejection port and its surroundings, becoming a stuck substance. The adhered substances are cleaned by a cleaning treatment method such as bath-type ultrasonic cleaning.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, it is not possible to completely remove the stuck substances stuck to the ejection opening of the inkjet head and the ink flow path around the ink jet head by ultrasonic cleaning in the second bath. Since the formed ink flow path has a very fine uneven shape, it is not possible to use a cleaning treatment method such as scrubber cleaning that removes stuck substances by mechanical contact.

If the inkjet head is used to continue recording while the adhered substances remain on the wall of the ink flow path, the adhered substances will peel off from the wall of the ink flow path as the ink is repeatedly ejected, and will be carried by the ink and pulled away. However, there is a problem in that the discharge port is clogged.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and it is possible to completely remove stuck substances stuck to the ejection port and its surroundings when the ejection port of an inkjet head is perforated using a short wavelength laser beam. It is an object of the present invention to provide a cleaning treatment method for an inkjet head, which can remove inkjet head particles quickly and prevent ejection ports from being clogged with adhered substances.

[Means for Solving the Problems 1] In order to achieve the above object, the inkjet head cleaning method of the present invention includes an inkjet head in which an ink flow path is formed, and an ejection port that communicates with the ink flow path. This method is characterized in that after drilling a hole by irradiating a short-wavelength laser beam from the roadside, water to which ultrasonic vibrations have been applied is ejected to the ejection opening of the inkjet head and its surroundings.

Further, after drilling an ejection port communicating with the ink flow path in the inkjet head in which the ink flow path is formed by irradiating a short wavelength laser beam from the ink flow path side, arranging a plurality of the inkjet heads in a line, A jetting means for jetting water to which ultrasonic vibrations have been applied is moved along the direction of the row of the inkjet heads, and water to which ultrasonic vibrations have been applied to the ejection openings of each inkjet head and its surroundings is ejected from the jetting means. There are some that spray, and some that have multiple injection means.

[Operation 1] In the inkjet head cleaning method of the present invention configured as described above, the water in which cavities are generated due to the application of ultrasonic vibration is applied to the ejection ports and their surroundings that are perforated by the short wavelength laser beam. When the cavity is injected and the cavity disappears, the impact removes the solid matter stuck to the discharge port and its surroundings. Further, the removed adhered substances flow away from the discharge port and its surroundings together with the jetted water.

〔Example) Embodiments of the present invention will be described based on the drawings.

First, the inkjet head will be explained.

In Fig. 2 fat right and fbl, workpiece 1 is an inkjet head that records on a recording medium by ejecting ink from an ejection port, and is made of ink-resistant resin and is integrated by injection molding or other methods. It is molded. A hole 2a is provided on one surface of the top plate portion 3 having a rectangular parallelepiped shape.
An ink supply port portion 2 having a top plate portion 3 is formed.
A concave common liquid chamber (not shown) communicating with the hole 2a and a plurality of groove-shaped ink channels (not shown) each communicating with the common liquid chamber are provided on the surface opposite to the ink supply port 2. ) are formed. A plate-like part 4 is formed at the end of the top plate part 3, and the surface of the plate-like part 4 on the opposite side from the top plate part 3 becomes a discharge port surface 4a in which a plurality of discharge ports are opened. ing.

The plurality of ink channels 5, ejection ports 6, etc. will be explained with reference to FIGS. 3, 4(a), and 4(b). Here, FIG. 3 is a perspective view of the main parts of the work 1 shown in FIG.
Figure fa) is a sectional view of Figure 2 (A-A in bl, Figure 4 +b+
is a BB sectional view of FIG. 4 fa).

The plurality of ink channels 5 are formed parallel to each other at equal pitches, and each extends in a direction perpendicular to the back surface 4b of the plate-shaped portion 4. One end of each ink flow path 5 reaches the back surface 4b of the plate-shaped portion 4, and the other end reaches a common liquid chamber (not shown). - As an example, the pitch of the ink channels 5 is 70.5μ
m, and the depth of each ink channel 5 is 43.5 μm. Further, the ejection ports 6 are perforated at positions corresponding to the respective ink channels 5 of the plate-shaped portion 4 by a method described later.

When the inkjet head is completed, a substrate (not shown) equipped with ejection means for ejecting ink from each ejection port 6 is attached to the surface of the top plate portion 3 on which each ink flow path 5 is formed, Each ink flow path 5i3 and the common liquid chamber are sealed by the substrate. The ink supplied to the common liquid chamber through the hole 2a of the ink supply port 2 flows into each ink flow path 5 and is discharged from each discharge port 6 by the discharge means.
are discharged from each.

Next, the work l in which each of the ink channels 5 is formed,
An example of a method of perforating each ejection port 6 that communicates with each ink flow path 5 by hitting a short wavelength laser beam will be described. The fifth section schematically shows the laser processing machine 10.

The workpiece 1, on which each ink flow path 5 has been formed in advance, is taken out from a tray 17 (see Fig. 6. A large number of workpieces 1 are stored in the tray 17) by an industrial robot such as an automatic hand and placed in a position. It is placed on the adjustment device 15 with the ink supply port 2 facing downward. On the other hand, laser oscillator 1
The excimer laser light, which is a short wavelength laser light emitted from the mask 1, passes through the illumination optical system 12 and irradiates the mask 13, which has a plurality of fine holes, with uniform intensity. The excimer laser light leaking from each microhole of the mask 13 passes through the imaging optical system 14 and enters the ink flow path 5 of the work l.
The back surface 4b of the plate-shaped portion 4 is irradiated from the side.

An image of the mask 13 is formed on the back surface 4b of the plate-shaped portion 4 by the excimer laser beam transmitted through the imaging optical system 14. This positioning of the image of the mask 13 is performed by moving the workpiece 1 relative to the excimer laser beam with high precision in um units using the position adjustment device 15 that utilizes image processing. Further, the optical axis 1 of the excimer laser beam
6 and the direction in which the ink flow path 5 extends, there is a risk that the excimer laser light will hit the wall surface of the ink flow path 5 and be reflected.
The direction in which the ink flow path 5 extends is inclined by an appropriate angle with respect to the ink flow path 5.

The portion of the back surface 4b that is irradiated with the excimer laser beam is
The interatomic bonds of the resin are broken and the gas is released into the air, and as a result, each of the discharge ports 6 is perforated. Further, each of the ejection ports 6 is arranged in the direction of irradiation of excimer laser light (from the ink flow path 5 to the ejection surface 4), as shown in FIG. 4(b).
The finished product has a shape in which the inner width gradually decreases as it advances in the direction a).

As shown in FIG. 3 or FIG. 4 fb), a part of the gas released into the air sticks to the wall surface of each ejection port 6 and the ink flow path 5 around it, and becomes a stuck object. It becomes 7.

Next, at each discharge port 6 of the work l and its surroundings,
A cleaning jig for fixing a workpiece 1 when spraying water to which ultrasonic vibrations have been applied will be described with reference to FIGS. 1 and 7.

At both ends of the bottom plate 22, there are two side plates 21a parallel to each other,
21b is perpendicular to the bottom plate 22 with two screws 2.
9e and 29f (the others are not shown) are fixedly attached, and the bottom plate 22 has a long hole 22a extending in the longitudinal direction thereof. Each side plate 21a, 21
Support plates 21c and 21d are provided perpendicularly to the side plates 21a and 21b and in parallel with the bottom plate 22, respectively, protruding outward. Between the two side plates 21a and 21b, an elongated plate-shaped work holder 25 has both ends attached to each side plate 21a and 21b with two screws 29a to 29, respectively.
d, and the work holder 25 is inclined with respect to the bottom plate 22. On one side of the work holder 25 near the bottom plate 22, eight concave holding parts 23a to 23h are formed at equal intervals, and steps 24a to 24h are formed on the inner wall of each holding part 23a to 23h, respectively. It is formed. On the other hand, the two side plates 21a,
The shaft 28 has both ends fixed to the shaft 21b.
One end of each of the eight presser plates 26 (in FIG. 7, 1@ is shown for ease of understanding) is rotatably fitted, and each of the eight presser plates 26 is The end portions are located at positions corresponding to the respective holding portions 23a to 23h. Further, one coil spring 27 is disposed between the other end of each presser plate 26 and the bottom plate 22, and the elastic force of each coil spring 27 causes the other end of each presser plate 26 to are always biased in the direction of arrow C.

As shown in FIG. 1, in the workpiece 1, the top plate part 3 is fitted into the holding part 23a, and the edge of the surface of the top plate part 3 on the ink supply port part 2 side comes into contact with the step 24a. In this state, the discharge port surface 4
The work 1 is fixed to the work holder 25 by being pressed in the direction of arrow C by one surface of the other end of the holding plate 26. With the same configuration, eight workpieces 1 are fixed to one cleaning jig 20. Further, when the work l is fixed, the discharge port surface 4a is inclined slightly toward the bottom plate 22 from a position perpendicular to the bottom plate 22.

Next, at each discharge port 6 of the work l and its surroundings,
A cleaning device that cleans a workpiece 1 by spraying water to which ultrasonic vibrations have been applied will be described.

In FIGS. 8(a) and fb), in the upper part of the cleaning device 30, a cleaning section 31, a dry air blower section 32, and a hot air drying oven section 33, which will be described later, are arranged in a line starting from one end. Further, a transport mechanism 34 is provided for transporting the cleaning jig 20 to pass through a cleaning section 31, a dry air blower section 32, and a hot air drying oven section 33 in sequence.

Here, the transport mechanism 34 will be explained.

A pair of fixed plates 36a and 36b, which are longer than the length from one end to the other end of the cleaning device 30, pass through the cleaning section 31, the dry air blow section 32i3, and the hot air drying oven section 33, respectively, and are horizontal and parallel to each other. is fixed to the cleaning device 30. A plurality of protrusions are formed on the upper side of each of the fixing plates 36a, 36b at equal intervals from one end to the other, and the spacing between the protrusions is such that the support plates 21c, 21d of the cleaning jig 20 are placed between them. It has a length that allows it to be inserted. Inside the pair of fixing plates 36a, 36b, a pair of fixing plates 36a, 36b and a pair of conveying plates 35a, 35b, each having the same shape, are installed horizontally and parallel to each other.
a, 36b, respectively, and the pair of conveyance plates 35a, 35b are moved in the direction of the arrow within a plane including each conveyance plate 35a, 35b by a driving means (not shown) while maintaining this posture. It is configured to rotate.

The operation when the cleaning jig 20 is transported by the transport mechanism 34 will be described with reference to FIGS. In addition, in FIG. 9 fa) to fe), the conveyor plate 3
5a is shaded to distinguish it from the fixing plate 36a, but the cross section is not shown.

The cleaning jig 20 is arranged between a pair of fixed plates 36a and 36b.
Each support plate 21c, 21d at both ends is connected to each fixed plate 36a, 36.
(Fig. 9 fa)
? hill). At this time, the long direction of the cleaning jig 20 is the fixed plate 3.
6a, and is perpendicular to the bottom plate 2 of the cleaning jig 20.
2 is downward. The supporting plates 21c and 21d at both ends of the cleaning jig 20 are moved by the fixed plates 36a and 35b, respectively, by the conveying plates 35a and 35b, which rotate and rise in the direction of the arrow.
36b (9th section + b + g light), and after passing over one protrusion of each fixed plate 36a, 36b, they are lowered and placed in the adjacent recesses (between the protrusions) (Fig. 9). fc)). The pair of transport plates 35a and 35b then continue to rotate in the direction of the arrow and descend (see FIG. 9fd)), and rise again to reach the support plates 21c and 21d of the cleaning jig 20, respectively. (see FIG. 9 fe)), repeat the same operation as described above. In this way, the cleaning jig 20 has a pair of fixed plates 36a, 3
6b is conveyed in the direction of arrow ErlE from one end to the other end.

Next, the cleaning head, which is a spraying means provided inside the cleaning section 31, will be explained with reference to FIG.

The cleaning head 40 is provided with a water inlet 43 connected to a pure water supply device (not shown), and pure water 44 is supplied into the cleaning head 40 through the water inlet 43 by the pure water supply device. A known ultrasonic vibrator 41 that oscillates ultrasonic vibrations of, for example, 1.5 MHz is provided at a position in the cleaning head 40 that comes into contact with the pure water 44 . The pure water 44 subjected to ultrasonic vibration by the ultrasonic vibrator 41 is ejected from a nozzle 42 provided in the cleaning head 40 by known means.

Two of the cleaning heads 40 are mounted side by side on one bracket (not shown) provided inside the cleaning section 31 via a known moving means (not shown). are located above the cleaning jig 20 that has been transported to a predetermined position inside the cleaning section 31 by the transport mechanism 34. Each nozzle 4 of the two cleaning heads 40
The second arrangement will be explained. Among the eight works l fixed in a row on the cleaning jig 20, when the nozzle 42 of one cleaning head 40 is located above the first work 1 from one end side, the nozzle 42 of one cleaning head 40 is located above the fifth work l. The nozzles 42 of the two cleaning heads 40 are located above the two workpieces 1 with the three workpieces 1 sandwiched between them. They are spaced apart so that the Further, the jetting direction of the pure water 44 jetted from each nozzle 42 is set to the first direction.
As shown in the figure, they are each perpendicular to the bottom plate 22 of the cleaning jig 20. 2 attached to the front 21 brackets
The cleaning heads 40 are both reciprocated by the moving means along the direction of the row of eight works I of the cleaning jig 20.

As shown in FIG. 8(b), a tray 37 is disposed below the cleaning section 31 and the dry air blow section 32, and the tray 37 is connected to a waste water treatment device (not shown). A drainage duct 38 connected to is connected. The dirty pure water jetted from the nozzle 42 of each cleaning head 40 and used for cleaning each workpiece 1 flows down into the tray 37 and flows through the drainage duct 38 to the waste water treatment device. In addition, each workpiece l is
Similarly, the dirty pure water that has been blown off from the
and flows through the drainage duct 38 to the wastewater treatment equipment.

Next, an example of a method for cleaning the workpiece I, which is an inkjet head, using the aforementioned cleaning device 30 will be described.

The workpieces 1 having respective discharge ports 6 perforated by the laser processing machine 10 are set in an automatic feeding device (not shown), and the automatic feeding device fixes eight workpieces to one cleaning jig 20. The cleaning jig 20 is connected to the transport mechanism 34 of the cleaning device 30.
and is transported in the direction of arrow E by the transport mechanism 34. When the cleaning jig 20 reaches a predetermined position inside the cleaning section 31 and stops, the cleaning jig 2
The first workpiece 1 from one end of the eight workpieces l of 0
The purified water 44 to which the ultrasonic vibrations have been applied is supplied from each nozzle 42 of the two cleaning heads 40 located above the fifth workpiece 1 to each discharge port of the first and fifth workpieces 1. 6i3 and the wall surface of the ink flow path 5 around it are simultaneously injected. During this jetting, the two cleaning heads are reciprocated an appropriate number of times by the width of one workpiece 1 by the moving means, and are evenly sprayed from one end of each workpiece 1 to the other end (the pure water 44. When the spraying onto the first and fifth workpieces 1 is completed, the two cleaning heads 40 are moved by the moving means, and each nozzle 42 of the two cleaning heads 40 is sprayed onto the second workpiece 1. They move above the first and sixth workpieces l.Next, the pure water 44 to which the ultrasonic vibrations have been applied is simultaneously injected from the respective nozzles 42 onto the second and sixth workpieces l, as described above. 8 or more repeating operations are performed sequentially up to the 4th work 1 and the 8th work 1, and the pure water 44 is sprayed onto the 8 works 1 fixed to one cleaning jig 20. Finish the operation.

Next, the cleaning jig 20 starts to be transported in the direction of arrow E by the transport mechanism 34 and moves into the dry air blow part 32 . Inside the dry air blowing section 32, dry air is blown onto each work l to remove water. The cleaning jig 20 is then moved from the dry air blow part 32 to the inside of the hot air drying oven section 33, and each work l is completely dried and then moved out of the hot air drying oven section 33.

In this embodiment, ultrasonic vibration (for example, 1.5 MHz) is applied to the pure water 44 supplied into the cleaning head 40 by the ultrasonic vibrator 41 to generate a cavity. The pure water 44 is injected onto the walls of the ink flow path 5 around each of the ejection ports 6 and the surroundings thereof, which are perforated by the excimer laser beam of the workpiece 1, and the impact generated when the cavities disappear causes each of the ejection ports 6 and the surroundings thereof to be damaged. Ink flow path 5
Remove the stuck object 7 stuck to the wall surface. Further, the removed stuck matter 7 flows away from the wall surface of each discharge port 6 and the ink flow path 5 around it together with the jetted pure water 44.

As a result, when an inkjet head made of the workpiece 1 is used for recording, as the ink ejection ratio is repeated as in the conventional case, adhered substances are peeled off from the wall of the ink flow path, causing the ejection opening to become It is possible to prevent the discharge port from becoming clogged.

Although the cleaning jig 20 shown in this embodiment is capable of fixing eight workpieces 1, it is not limited to eight and may be any device that can fix a plurality of workpieces l. Further, although an example has been shown in which pure water 44 subjected to ultrasonic vibration is jetted from two cleaning heads 40, the number of cleaning heads 40 does not need to be limited to two, and a plurality of cleaning heads 40 may be used as appropriate. Cleaning head 40
We have shown an example where the interval is the interval for ヰ pieces of workpiece 1, but
There is no need to limit it to this, and it may be changed as appropriate depending on the number of workpieces fixed to the cleaning jig and the number of cleaning heads 40.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.

By spraying water to which ultrasonic vibrations have been applied to the ejection opening of the inkjet head, which has been perforated by irradiation with a short-wavelength laser beam, and its surroundings, the stuck substances that have adhered to the ejection opening and its surroundings can be completely removed. It can also be removed,
Since the adhered substances flow away together with the injected water, they do not re-adhere to the discharge port and its surroundings. As a result, it is possible to prevent the ejection ports of the inkjet head from being clogged with the adhered substances.

[Brief explanation of the drawing]

FIG. 1 is a composite diagram showing a schematic diagram of a cleaning head according to an embodiment of the present invention and a sectional view of a cleaning jig, and FIG. 2 is a diagram showing a workpiece according to the same embodiment, where fal is a front view. 3 is a perspective view of the main part of the work shown in FIG. 2 fal seen diagonally from below, and FIG. 4 is a cross-sectional view of the work of the same example, fa) is Fig. 2 A-A sectional view of tb+,
(b) is a sectional view taken along line B-B in Fig. 4(a), Fig. 5 is a schematic diagram of the laser processing machine of the same embodiment, Fig. 6 is a perspective view of the tray of the same embodiment, and Fig. 7 is the same. Perspective view of the cleaning jig of the embodiment, No. 8
The figures show the cleaning device of the same embodiment, in which (a) is a front view, (b) is a left side view of (a), and FIGS. 9(a) to (e).
) is an explanatory diagram for explaining the operation of the transport mechanism of the cleaning device of the same embodiment. 1... Work, 2... Ink supply port,
3...Top plate part, 4...Plate part, 4a...
・Discharge port surface, 4b...back surface, 5...ink flow path, 6...discharge port, 7...sticky object,
10... Laser processing machine, 11... Laser oscillator, 2
0...Cleaning jig, 21a, 2 l b--Side plate, 21c, 21 d--Support plate, 22--Bottom plate, 22a--Long hole, 23 a
~23h - holding part, 24a ~24h = stage, 25-... work holder, 26... presser plate, 27-... coil spring, 28-- shaft, 29 a ~29
f-screw, 30-...Cleaning device, 31...Cleaning section, 32...Dry air blower part, 33...Hot air drying oven section, 34...Transport mechanism, 37...
...The receiver is a plate, 38...Drainage duct, 40...
・Cleaning head, 41... Ultrasonic vibrator, 42...
Nozzle, 43... Water inlet.

Claims (1)

[Scope of Claims] 1. After drilling an ejection port communicating with the ink flow path in an inkjet head in which an ink flow path is formed by irradiating a short wavelength laser beam from the ink flow path side, An inkjet head cleaning method comprising jetting water to which ultrasonic vibrations have been applied to the ejection port and its surroundings. 2. After drilling an ejection port communicating with the ink flow path in the inkjet head in which the ink flow path is formed by irradiating a short wavelength laser beam from the ink flow path side, arranging a plurality of the inkjet heads in a line; A jetting means for jetting water to which ultrasonic vibrations have been applied is moved along the direction of the row of the inkjet heads, and water to which ultrasonic vibrations have been applied to the ejection openings of each inkjet head and its surroundings is ejected from the jetting means. A method of cleaning an inkjet head. 3. The inkjet head cleaning method according to claim 2, wherein the number of ejecting means is plural.