JP3317840B2 - Method for implanting water repellent ions into orifices and ink jet nozzles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of charging an ink droplet ejected from a liquid ejecting nozzle, and deflecting the charged ink particle by a deflecting electrode to land on a recording medium. Orifice is a component of a charged deflection type liquid jet recording device that performs recording on
Of water-repellent agent ion to the nozzle and ink jet nozzle
It is about the law .

[0002]

2. Description of the Related Art As a technique for preventing clogging of ink in a nozzle portion of a charged deflection type liquid jet recording apparatus, for example, as described in Japanese Patent Application Laid-Open No. 4-39055, a cleaning method surrounding an ink nozzle is disclosed. A technique has been proposed in which a chamber is provided and a cleaning liquid is supplied to a nozzle in the cleaning chamber to perform cleaning.

[0003]

However, in the above-mentioned prior art, since a flow path for supplying a cleaning liquid is required, there arises a problem that the apparatus becomes complicated and large. In addition, when an organic solvent is used as the cleaning liquid, an environmental problem occurs due to volatilization of the organic solvent. Further, since the ink is excessively diluted by the cleaning liquid, the viscosity of the ink is reduced, and as a result, there is a problem that the particleization of the ink becomes unstable.

SUMMARY OF THE INVENTION An object of the present invention is to provide an orifice and an orifice for preventing ink clogging and stabilizing ink ejection characteristics without complicating the configuration of a charged deflection type liquid jet recording apparatus.
And a method for implanting a water repellent into the ink jet nozzle .

[0005]

In order to achieve the above object, the present invention provides an orifice having an ink discharge port for jetting ink, and a method for applying a vibration to the ink to discharge the ink from the ink discharge port. An ink ejecting nozzle for atomizing and ejecting, a charging electrode for charging the ejected ink particles, and a deflecting electrode for deflecting the flying direction of the ink particles when the charged ink particles fly in an electrostatic field. Water repellency to the orifice and the ink jet nozzle of a charged deflection type liquid jet recording apparatus that performs recording on a recording medium with ink particles whose flight direction is deflected.
A method of implanting agent ions, said orifice and
Connect the ink supply side of the ink jet nozzle to the water repellent ion
The water repellent to the ink supply side
Ion implantation direction with respect to the center axis of the orifice
The orifice and the ink jet nozzle
While rotating the nozzle, the orifice and the ink
The method is characterized in that the water repellent ions are implanted into the inner wall surface of the spray nozzle .

Another feature of the present invention is that the orifice
And the ink ejection side of the ink jet nozzle
The orifice and the
The water repellent ions are injected into the outer wall of the ink jet nozzle
In the no-thing.

[0007]

According to the present invention, an orifice and an ink jet are provided.
Set the ink supply side of the injection nozzle to the water repellent ion implantation side.
The water repellent ion implantation direction to the ink supply side
At an acute angle to the center axis of the orifice and at the orifice
And the orifice and
Water repellent ions are injected into the inner wall surface of the ink jet nozzle.
The orifice and the ink ejection side of the ink ejection nozzle
With the orifice and
Water repellent ions are injected into the outer wall of the nozzle.

Thus, a cylindrical surface concentric with the ink discharge port is provided.
The inner and outer walls of the ink jet nozzle
To effectively and evenly implant water repellent ions
it can. As a result, the orifice and ink jet nozzle
Water repellency acts on all surfaces of the inner and outer walls that come into contact with the ink, making it difficult for the ink in the ink supply port to adhere to the ink supply port and the ink discharge port, and for the ink to adhere to the discharge side surface of the orifice. becomes hard, Ki out to prevent clogging of the nozzles, the ink ejection characteristics can be stabilized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A charged deflection type liquid jet recording apparatus according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a charged deflection type liquid jet recording apparatus according to an embodiment of the present invention. As shown in FIG. 1, the nozzle unit 1 ejects pressurized ink pressurized at a predetermined pressure by a pressurizing source (not shown). Thereafter, the pressurized ink in the nozzle unit 1 is regularly turned into particles after being ejected from the nozzle unit 1 by the vibration of the electrostrictive element 2 whose frequency and amplitude are controlled by the print control unit (not shown). .

The ink particles 7 are charged to a predetermined value in the charging electrode 3 of which the applied voltage is controlled by the print control unit, and furthermore, the electrostatic field in the deflection electrode 4 to which the predetermined voltage is applied. While flying through the inside, it receives a deflecting force according to the charged charges and is deflected upward in the figure. The deflected ink particles 7 are transported at a speed Vc in a direction indicated by an arrow in FIG.
And an image is formed on the recording medium 6.

The ink particles 7 to which no charge is given are:
The light travels straight without being deflected in the deflection electrode 4, is collected by the gutter 5, and is reused.

In this embodiment, the ink jet nozzle 8
And an ion implantation layer 12, which is a water-repellent layer, is formed on the inner wall surface of the orifice 10 by ion implantation.
Since the ink is hardly fixed, it is possible to prevent nozzle clogging when the apparatus is restarted after the apparatus is stopped.

FIG. 2 shows a cross section of the ink jet nozzle 8 and the orifice 10 of the nozzle section 1 of FIG. 1 and shows a state of ion implantation. An ink ejection nozzle 8 is provided at an ink ejection portion of the nozzle portion 1, and an orifice 10 having an ink ejection port 11 opened is fitted on the ink ejection side of the ink ejection nozzle 8, and the orifice 10 is smoothly provided on the ink supply side. A conical ink supply port 9 is provided so that ink flows in.

The orifice 10 is made of a material such as ruby or sapphire in order to maintain the hole accuracy of the ink discharge port 11 and to stably maintain the ink particle formation characteristics against fluctuations in the operating environment. . Further, the main body of the ink jet nozzle 8 is made of a metal such as stainless steel which is excellent in corrosion resistance to ink, workability, and the like.

However, when the charge control type liquid ejecting apparatus is left after printing, the ink adheres to the inside of the orifice 10, and the hole diameter becomes smaller than the diameter of the predetermined ink discharge port 11, and the predetermined ink particle diameter becomes smaller. You can't get it. When the fixing of the ink further proceeds, the ink ejection port 1
1 is completely clogged, ink cannot be ejected, and printing cannot be resumed. For this reason, conventionally, measures such as cleaning the ink ejection port 11 after printing is taken. However, this method has the drawbacks that the apparatus becomes complicated as described above, and that the density of the ink becomes unnecessarily low.

In order to solve the ink clogging, it is conceivable to perform a so-called water repellent treatment for lowering the wettability of the ink in the ink discharge port 11. However, in a general water repellent treatment method, a water repellent is applied. , Ink ejection port 1 with strict dimensional accuracy
1 changes the inner diameter. In addition, the ink ejection port 11
The application of the water repellent to the inner surface of the device itself is a difficult task.

Therefore, in the present embodiment, the surface of the nozzle portion 1 in contact with the ink is modified by utilizing ion implantation conventionally used for doping impurities in the field of semiconductor manufacturing. Ion implantation ionizes the element to be implanted, accelerates the ion, irradiates the object with the ion implantation, and implants the ion into the object. The combination of the ion implantation target is arbitrary. Therefore, it is possible to obtain surface characteristics corresponding to the ink.

[0020] As shown in FIG.
After the ink ejecting nozzle 8 is fixed, the ions are ejected into the ink ejecting nozzle 8 so that the axial direction 1 and the ejection direction of the ion stream 13 are substantially parallel and the ink supply side is the ion ejecting side. Here, fluorine ions are injected into the aqueous ink so as to obtain water repellency.

The ions to be implanted are not limited to fluorine, but may be appropriately selected so as to reduce the surface energy with respect to the ink used. For example, similar effects can be obtained by using argon ions or nitrogen ions. be able to. In addition, when using oil-based ink, it is easy to obtain oil repellency by appropriately selecting the type of ions to be implanted.

As a result, as shown in FIG. 2B, an ion-implanted layer 12a is formed on the ion-implanted side of the ink jet nozzle 8.

As shown in FIG. 3A, the ink ejection nozzle 8 is set so that the ink ejection side is the ion implantation side.
Is reversed, and ions are implanted in the same manner as in FIG. As a result, as shown in FIG. 3B, the ion implantation layer 12b is also formed on the ink ejection side of the ink ejection nozzle 8. As described above, by ion-implanting the water repellent from both the ink supply side and the ink discharge side of the ink ejection nozzle 8 and the orifice 10, all the surfaces that come into contact with the ink can be subjected to the water repellent treatment.

As a result, it becomes difficult for the ink in the ink supply port 9 to adhere to the ink inflow port 9 and the ink discharge port 11, and it is possible to reduce nozzle clogging. Further, it becomes difficult for the ink to adhere to the surface of the orifice 10, and the problem that the ink ejection port 11 is blocked from the outside, such as bending in the flying direction of the ink, can be solved.

The properties of the ion implantation layer 12 can be variously changed by selecting the type of ions. In addition, it is necessary to precisely control the ion implantation conditions such as ion acceleration voltage, ion irradiation time, and ion beam current. Can be.

According to this embodiment, since the ink flow path is not coated with the water-repellent layer, the ink flow path size can be controlled with the initial machining accuracy, and the dimensional error of each ink nozzle can be reduced. Can be.

FIG. 4 shows a cross section of the ink jet nozzle 8 and the orifice 10 and shows another state of the ion implantation process.

In the present embodiment, the ions are ejected by fixing the ink jet nozzle 8 so that the axis AA of the ink ejection port 11 and the ejection direction of the ion stream 13 form an acute angle R. In this manner, ions can be effectively implanted into the inner wall surface of the ink ejection port 11 and the region of the ink ejection nozzle 8 which forms a cylindrical surface concentric with the axis of the ink ejection port 11.

Further, ions are injected while rotating the axis AA of the ink ejection port 11 as a rotation axis, or ions are implanted each time the ink ejection port 11 is rotated, so that the entire area of the region forming a cylindrical surface concentric with the ink ejection port 11 is formed. On the other hand, ions can be uniformly implanted.

FIG. 5 is a perspective view showing a state in which ion implantation is performed on the plurality of ink jet nozzles 8 and the orifices 10 attached to the rotary table.

As shown in FIG. 5, a plurality of ink jet nozzles 8 are fixed by a fixing screw 23 on a rotating table 21 rotatable about a rotation center axis 22.
The rotation table 21 is attached so that the rotation axis AA of the rotation center axis 22 forms an angle R with respect to the driving direction. With such a configuration, as in FIG.
Ions can be uniformly implanted over the entire inner wall surface and the entire area of the ink jet nozzle 8 which forms a cylindrical surface concentric with the ink discharge port 11.

In FIG. 5, the method for fixing the ink jet nozzle 8 to the rotary table 21 is such that the ink jet nozzle 8 is fixed to the nozzle base 14 so as not to affect the characteristics of the ink jet nozzle after the surface modification. By also using the fixing screw to be used, complication of the device can be avoided.

FIG. 6 shows a cross section of the nozzle portion in a state where the nozzle cap is attached to the surface on the ink discharge side. FIG.
FIG. 7 is a cross-sectional view of a nozzle portion in a state where an ink discharge port is covered by the nozzle cap of FIG. 6. As shown in FIG. 6, the ink jet nozzle 8 whose surface that comes into contact with the ink has been water-repellent is fixed to the nozzle base 14 in which the ink supply channel 15 is formed. At this time, a packing 16 is provided around the ink supply path 15 to prevent ink from leaking.

A nozzle cap 17 as a closing member having a pressure chamber 18 and a wiping groove 19 is slidably held on the surface of the ink ejection nozzle 8 in contact with the ink ejection side surface of the ink ejection nozzle 8. Have been.

After the printing is completed, when no pressure is applied to the ink in the ink supply path, the ink is not discharged from the ink discharge port 11, and an ink meniscus 20 is formed near the ink outlet of the ink discharge port 11. Is done. If the nozzle is left in this state, the ink remaining in the ink ejection port 11 having the narrowest ink flow path contacts the outside air and solidifies, causing clogging of the nozzle.

Therefore, as shown in FIG. 7, after printing is completed, the nozzle cap 17 is slid over the surface of the ink jet nozzle 8 so that the pressure chamber 18 covers the ink discharge port 11. In this way, even if the ink in the ejection port 11 comes into contact with the air in the pressure chamber 18 and the solvent of the ink in the ejection port 11 evaporates slightly, unlike the case where the ink in the ejection port 11 is directly in contact with the outside air, Due to the small volume of air in the pressure chamber 18,
The concentration of the vapor of the solvent in the ink in the ink rapidly rises and approaches a saturated state, the speed of gas diffusion of the solvent in the ink is suppressed low, and the ink in the ejection port 11 is hard to solidify.

Further, after closing the ink discharge port 11 with the nozzle cap 17, a negative pressure is applied to the ink in the ink supply path 15 to retreat the meniscus 20 from the orifice 10.
By moving the ink from the ink discharge port 11 to a place having a larger inner diameter, even if the ink solidifies from the meniscus 20, the ink in the ink supply path 15 can be easily applied by applying pressure during normal printing. The solidified meniscus 20 can be broken, and clogging of the nozzle can be prevented.

The nozzle cap 17 has a wiping groove 1 in a direction substantially perpendicular to the moving direction of the nozzle cap 17.
When the nozzle cap 17 moves, dirt and the like adhering to the surface of the ink ejection nozzle 8 are introduced into the wiping groove 19 and the ink ejection port 11 is provided.
To prevent being pushed inside. For this reason, it is desirable that the wiping groove 19 be formed up to the outer periphery of the nozzle cap 17 and make a predetermined angle from a direction perpendicular to the moving direction of the nozzle cap 17.

Note that, depending on the type of ink, environmental conditions, and the like,
It is also possible to prevent clogging of the nozzle only by moving the meniscus 20 without using the nozzle cap 17.

As described above, conventionally, the cleaning liquid is supplied to the nozzle portion when the apparatus is stopped, and the cleaning liquid is ejected from the orifice for a predetermined time to discharge the ink inside the nozzle, and the apparatus is stopped. During this time, the ink was prevented from solidifying and adhering to the inside of the nozzle. But,
In the conventional method, there is a problem that the concentration of the ink is reduced by the cleaning liquid, and thus the conditions for forming the ink particles are changed.

However, in the charge control type liquid jet recording apparatus of this embodiment, since the water repellency is imparted to the inner and outer wall surfaces of the nozzle by ion implantation, the ink inside the nozzle can be removed with a small amount of the cleaning liquid. As a result, the amount of the cleaning liquid used for nozzle cleaning can be reduced, and the amount of decrease in the ink density can be reduced. Further, it is possible to further stabilize the ink ejection characteristics while suppressing the change in the ink density to the minimum necessary.

[0042]

According to the present invention, an orifice and an ink
Tilt the injection nozzle with respect to the ion
By inverting and injecting water repellent ions, ink clogging can be prevented and the ink ejection characteristics can be stabilized, so that the reliability of the charged deflection type liquid jet recording apparatus can be improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a charged deflection type liquid jet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a cross section of the nozzle portion of FIG. 1 and showing a state of ion implantation on the ink supply side.

FIG. 3 is a diagram showing a cross section of the nozzle portion of FIG. 1 and showing a state of ion implantation on the ink ejection side.

FIG. 4 is a diagram showing a cross section of the nozzle portion of FIG. 1 and showing another state of ion implantation on the ink supply side.

FIG. 5 is a perspective view showing a state in which ion implantation is performed on a plurality of nozzles attached to the rotary table.

FIG. 6 is a diagram showing a cross section of the nozzle portion of FIG. 1, showing a state in which a nozzle cap is attached to an ink ejection side surface.

FIG. 7 is a cross-sectional view of a nozzle portion in a state where an ink discharge port is covered by a nozzle cap of FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Nozzle part, 2 ... Electrostrictive element, 3 ... Charging electrode, 4 ... Deflection electrode, 5 ... Gutter, 6 ... Recording medium, 7 ... Ink particle,
8 ... ink ejection nozzle, 9 ... ink supply port, 10 ...
Orifice, 11 ... Ink ejection port, 12, 12a, 12
b: ion implantation layer, 13: ion flow, 14: nozzle base, 15: ink supply path, 16: packing, 1
7: Nozzle cap, 18: Pressure chamber, 19: Wiping groove, 20: Meniscus, 21: Rotary table, 22: Rotating center axis, 23: Fixing screw

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoichi Inoue 502 Kandachicho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Takashi Minegishi 1-1-1 Higashitaga-cho, Hitachi-shi, Ibaraki Stock (56) References JP-A-6-320733 (JP, A) JP-A-62-121551 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) B41J 2/01 B41J 2/045 B41J 2/055 B41J 2/075 B41J 2/135

Claims (2)

(57) [Claims] An orifice having an ink ejection port for causing ink to flow in a jet stream; an ink ejection nozzle for applying vibration to the ink to form the ink into particles from the ink ejection port and ejecting the ink; And a deflection electrode for deflecting the flight direction of the ink particles when the charged ink particles fly in an electrostatic field. Charge-deflection type liquid jet recording device for recording on
Water repellent for the orifice and the ink jet nozzle
An ion implantation method, comprising: supplying ink to the orifice and the ink ejection nozzle.
Side to the water repellent ion implantation side, and the water repellent ion implantation direction to the ink supply side is
The orifice is inclined at an acute angle with respect to the central axis of the orifice , and the orifice and the ink jet nozzle are rotated.
The orifice and the ink jet nozzle
Characterized in that the water repellent ions are implanted into a wall surface.
Water repellent ion implantation into orifices and ink jet nozzles
Only way . 2. The water repellent according to claim 1, wherein the orifice and the ink ejection side of the ink ejection nozzle are provided with the water repellent agent.
The orifice and the ink jet
Impinging the water repellent ions on the outer wall surface of the injection nozzle.
Characteristic water repellent for orifice and ink jet nozzle
Ion implantation method.