JPS6280049A - Recorder - Google Patents

Abstract

PURPOSE:To enable atomized ink to be selectively sent flying through the separation of ink at the tip of a recording head per recording electrode by selectively applying a coating film consisting of inkphobic and highly insulative material on a surface between recording electrodes at the tip of a recording head. CONSTITUTION:A part except a part of distance d4 from the tip of a lower recording head 2 is coated surfacially with a highly insulative material 24. In addition, in the part d4 from the tip, a coating film 25 consisting of an inkphobic and highly insulative material ... is selectively applied between the individual second electrodes 7. In the case of an oily ink 13, this coating film 25... is of an oleophobic material, e.g. nitrided film of hydrogenated amorphous silicon or nitrided film of amorphous silicon. In the case of aqueous ink, the film is of a hydrophobic material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an inkjet type recording apparatus applied to, for example, printers, facsimile machines, and the like.

[Technical background of the invention and its problems]

Inkjet recording devices have traditionally been used in printers and facsimiles as a plain paper recording method that does not require developing or fixing operations, but electronic flat scanning is desired to improve high-speed recording and simplicity. ing.

Converting this inkjet recording device to electronic plane scanning has been studied mainly by using multiple nozzles, but this has not been put into practical use due to the problem of reduced reliability due to clogging of ink in each recording nozzle. is the current situation.

Therefore, the following slit jet type recording apparatus has been proposed prior to the present invention as a plane scanning inkjet type recording apparatus that does not have the disadvantages of the nozzle type described above.

That is, 1 in FIGS. 4 and 5 is a recording head, which is composed of a lower recording head section 2 and an upper recording head section 3. In FIG.

The lower recording head section 2 is made of a material such as Cr or Ni and patterned with a lower common electrode 5 on an insulating lower substrate (lower base) 4 at 8 electrodes/ml or 16 electrodes 7 mm thick. A gap d3 is maintained between the plurality of first individual electrodes (first recording electrodes) 6 . . . electrically connected to the lower common electrode 5 and the first individual electrodes 6 . second individual electrodes 7 facing one-on-one, and this second
For example, amorphous silicon (hereinafter referred to as vIa-3i) or amorphous selenium (hereinafter referred to as a-8e) is deposited in the gap d3 between the individual electrodes 7 and the first individual electrodes 6. ) etc. Photoconductor 11! l
(Photoelectric conversion member) 8...

The upper recording head section 3 forms a minute gap with the second individual electrodes 7 on an insulating upper substrate (upper substrate) 9 which faces the lower substrate 4 with a gap d2 maintained therebetween. The configuration includes upper common electrodes 10 that face each other in a uniform manner.

Further, a slit-shaped opening 11 having a gap d2 formed by the lower substrate 4 and the upper substrate 9 is formed at the tip of the recording head 1, and the liquid ink 13 supplied from the ink storage section 12 is formed at the tip of the recording head 1. An ink meniscus 14 is formed by this.

Further, a roller-shaped back electrode 15 is provided opposite the tip of the recording head 1, and a recording medium 16 such as plain paper is supported on this back electrode 15.

Further, an original table 17 is provided above the recording head 1 and operates in synchronization with the recording medium 16, and a focusing fiber lens array 18 and an exposure light are provided between the original table 17 and the recording head 1. An exposure system consisting of a light source 19 is provided.

By operating the switch, the document table 17 and the recording medium 16 operate in synchronization, and the light source 19 is turned on, and the optical image of the document on the document table 17 is irradiated onto the photoconductor film 8 through the fiber lens array 18. be done.

For example, the negative electrode of a DC power source 20 is connected to the lower common electrode 5, and the positive electrode of a DC power source 21 is connected to the upper common electrode 10.
. . , a negative potential is output to the tip of the recording head 1, and a positive potential is output to the dark area.

The principle of the above signal output can be explained using the circuit shown in FIG. That is, the resistance of the photoconductor film 8 when irradiated with light is ρph, and the resistance when it is dark is ρdark.

Ink 1 between upper common electrode 10 and second individual electrode 7
If the resistance of 3 is ρink, then ρph〈ρink〈ρd
The resistance ρin of the ink 13 is set so that the relationship ark holds true.
By adjusting k in advance, ρin during light irradiation
k becomes dominant, and the first DC power supply 20 outputs a negative potential to the tips of the second individual electrodes 7..., and in the dark, ρdark becomes dominant and the second DC amount if! 21 outputs a positive potential.

Next, the back electrode 15 is connected to the third DC power supply 22 to
When a pulsed voltage is applied to the negative polarity side of (2) and a positive potential is output to the tips of the second individual electrodes 7..., positive charges are injected into the ink meniscus 14. , the ink 13 flies toward the back electrode 15 side, thereby selectively recording on the recording medium 16 corresponding to the original image.

Note that it has been confirmed that sufficiently good recording by flying ink 13 is possible under the provision setting conditions shown below.

That is, the voltage applied to the lower common electrode 5 is between -50V and -I.
KV, the voltage applied to the upper common electrode 10 is 0 to +IKV, the back voltage 441! l) Applied 1ffi pressure O~-2, OKV
, the frequency of the back electrode 15 is 10~10kHz7, the gap d1 is 10μm~500μ7FL, and the frequency is 10~10kHz7. '/pd2 is 10 μm to 300 μm.

Further, although the value of the gap d3 varies depending on the specific resistance of the photoconductor film 8, the value of the gap d3 varies depending on the specific resistance of the photoconductor film 8.
'If there is 20μ7FL ~ 80μm, a -8
If it is e film or a-8eTe film, 5μTrL~50μ
It is m.

Also, the photoconductor 118 may be, for example, a-seII! J, ρdark is 109~1012Ωcrn, ρ
Since the pH is 105 to 108 ΩCff1, ink 1
The resistance ρ ink of No. 3 must be selected from 10 6 to 10 10 Ω.

Further, in the light image irradiated onto the photoconductor film 8, the dark portion is between 50Lux and 500Lux.

However, the above-mentioned slit jet type recording apparatus has the following drawbacks.

That is, as shown in FIG.
The second individual electrode 7 is
When an electrical signal like the waveform 22 is output only to the second individual electrode 7C among a to 7e, the resistance of the ink 13 is 106 to 10'Ω, for example, when the electrical signal is output to the second individual electrode 7C. As shown in FIG. 8, when the voltages of the second individual electrodes 7a to 7e are measured by the voltmeter 23, as shown in FIG. a second individual electrode 7b adjacent through the
It leaks to 7d.

Therefore, as shown in FIG. 7, originally the second individual electrode 7
In addition to the ink 13c that should be ejected only from C, a small amount of ink 13b and 13d also ejects, and as a result, inks 13b and 13d other than the recorded ink 130 are recorded, resulting in a so-called poor resolution.

Therefore, the second individual electrode 7 of the signal voltage due to the ink 13
In order to prevent leakage between...
As shown in Figure 0, from the end of the second individual electrode 7...
It is proposed to coat the surface with a highly insulating layer of 1!24, except for the area at a distance of 4.

However, the distance 1 from the end of the second individual electrode 7...!
The id4 part plays the role of injecting the output signal voltage into the ink 13, so this part is made of highly insulating material 11.
! 24 cannot be surface coated.

Therefore, the question is how narrow the distance d4 can be, but according to the experimental results, d4''
It has been confirmed that leakage of signal voltage to adjacent electrodes cannot be prevented in the range of o, iM1 to 2M.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to prevent the signal voltage from leaking to the adjacent electrode of the recording electrode to which the signal voltage is originally output. Another object of the present invention is to provide a recording device that can achieve high resolution by separating ink at the tip of a recording head for each recording electrode and selectively ejecting minute ink.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that a surface coating film made of an ink-phobic and highly insulating material is selectively coated between the recording electrodes at the tip of the recording head. It is something.

(Embodiment of the Invention) Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 3.The same constituent parts as those shown in Figs. The explanation will be omitted and only the configuration of the different main parts will be explained.

As shown in FIG. 1, the surface of the lower recording head section 2 excluding the distance d4 from the tip is coated with a highly insulating material 24, similar to the structure shown in FIG. 10 described above. . In addition, for a portion d4 from the tip, a surface coating film 25 made of an ink-phobic and highly insulating material is selectively coated between the second individual electrodes 7. When the ink 13 is oil-based, the surface coating film 25 is made of an oleophobic material, such as hydrogenated amorphous silicon nitride lI (hereinafter referred to as a-8iNiH film) or amorphous silicon nitride yI (hereinafter referred to as a-8iNiH film).
It is written as -8IN film. ), and if the ink is aqueous, it is hydrophobic.

According to such a configuration, the ink 13 is applied to the surface coating film 2.
5..., so the ink 13 exists only on the surface of the second individual electrode 7... at the tip of the lower recording head section 2, and the ink 13 is separated. Ru. Furthermore, the signal voltage does not leak to the adjacent second individual electrodes 7 .

Next, the surface coating film 25 is applied to the tip d of the lower recording head section 2.
In section 4, a method for selectively coating the surface between the second individual electrodes 7 will be explained.

As shown in FIG. 3(a), a plurality of second individual electrodes 7, made of Cr or the like are formed on the lower substrate 4 of the lower recording head section 2.
After patterning, highly insulating and oleophobic a-8i Ni Hll (
Surface coat I! 125) is coated on the surface, and then an ordinary photoresist solution is coated thereon using a spinner to form a photoresist layer 26. Here, the surface coating method of a-8i Ni HI [l by the glow discharge CVD method is commonly used, and the lower recording head section 2 is set in a reaction vessel under reduced pressure and the temperature 23
After raising the temperature to 0°C, SiH4 gas and N2 gas were mixed in 1:1.
In this method, a film is formed by introducing the components into a reaction vessel at a ratio of 10:1 and applying 200 W of radio freak engine power to a capacitively coupled counter electrode. Furthermore, a coating method using a photoresist solution using Sgunner is also a commonly used method.

Next, a light shielding section 27 corresponding to the second individual electrode 7...
UV irradiation 29 is applied from above the mask 28 having .

Next, as shown in FIG. 3(b), the unexposed portions of the photoresist layer 26 are removed using a negative developer.
Rinse after etching.

At this stage, a-8i NiH training (surface row 1 to film 25)
The photoresist layer 26 remains in the area where the upper second individual electrodes 7 are not present.

Next, this lower recording head section 2 is set in a dry type plasma etching device, and exposed to CF4 gas and 0
2 gases were introduced at a ratio of about 2=1 and a-8iNil-IB! was heated at about 300 W using microwaves. (Surface coat 11
25> is etched.

At this time, the a-8iNiH film (surface coating film 25
) is not exposed to the CF402 plasma, so the third
As shown in Figure (C), it is not etched.

Then, the a-8iNiH remaining after dry etching
The photoresist layer 26 on ll (surface coat jl 25 ) was peeled off using a resist 1 stripping solution, as shown in FIG. 3(d). In this state, a highly insulating and oleophobic a-8iNiH film (surface coating film 25) is selectively coated between the second individual electrodes 7 of the lower recording head section 2.

Next, when the lower recording head section 2 and the upper recording head section 3 created by the above method were assembled and the ink 13 was actually supplied, as shown in FIG. Distance d4 from the tip of the 8-3iNi)-1 film
The ink 13 spreads over the entire surface up to the part where the surface was selectively coated, but in the part d4 from the tip, the ink 13 was selectively present only on the second individual electrodes 7...

The optimal value of d4 varies depending on the surface tension and viscosity of the ink 13, but it has been confirmed that a range of 60 μm to 2fflIIl is appropriate. In addition, here d4 is 0
．． It was set as 5n+m.

Next, the lower recording head section 2 produced by the above method was incorporated into a slit jet type recording apparatus shown in FIG. 4, and an actual original was copied under the following process conditions.

In other words, the voltage applied to the lower common electrode ai5 is -300v1.
The voltage applied to the upper common 'iR electrode 10 is +150V, the voltage applied to the back electrode 15 is -700V, and the frequency is 1KH2.
, day-to-day tea was set at 50%. In addition, the diameter of the diameter d1 is 100 μm, the diameter of d2 is 100 μm, and the photoconductivity l1 is 100 μm.
8 was made of a-8iNiHIll, and d3 was set to 40 μm. The oil-based ink 13 has a surface tension of 28. Odyn
/Cam, viscosity is 7 centistokes, resistance is 10Ωa
m was used.

As a result, eight high-resolution copies of 7 mm were obtained.

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent the signal voltage from leaking to the adjacent electrode of the recording electrode to which the signal voltage is originally output, thereby improving the efficiency of the recording head. Since the ink at the tip can be separated for each recording electrode and the fine ink can be selectively ejected, excellent effects such as high resolution can be achieved.

[Brief explanation of drawings]

Figures 1 to 3 show one embodiment of the present invention.
The figure is a sectional view showing the tip of the recording head, FIG. 2 is a plan view showing the tip of the lower recording head, and FIGS.
d) is a diagram for explaining a method of surface coating with a surface coating film, and Figures 4 to 10 show an inkjet recording apparatus proposed prior to the present invention. The overall structure is schematically shown, FIG. 5 is a plan view showing the lower recording layer, FIG. 6 is an equivalent circuit diagram to explain the principle of selectively ejecting ink, and FIG. 7 is an adjacent circuit diagram. Fig. 8 is a side view for explaining the method of measuring the voltage of the second individual electrode, and Fig. 9 shows the signal voltage. FIG. 10 is a plan view showing another example of the lower recording electrode portion. 1... Recording head, 2... Lower recording head section, 3.
...Upper recording head section, 4...Lower substrate (lower substrate)
, 5... Lower common electrode, 6... First recording electrode (first individual electrode), 7... Second recording electrode Fi (second individual electrode), 8... Photoelectric electrode Conversion member (photoconductor film), 9.
... Upper base (upper substrate), 10... Upper common electrode,
DESCRIPTION OF SYMBOLS 11... Recording body, 13... Ink, 15... Back electrode, 16... Opening part, 25... Surface coating film. Applicant's Representative Patent Attorney Takehiko Suzue Figure 2 Figure 3 (a) 3I! 1(b) Figure 3(d) Figure 5 Figure 6

Claims (8)

[Claims] (1) A recording head having a slit-shaped opening formed by a minute gap at the tip and a plurality of recording electrodes provided in the opening, and a back electrode facing the tip of the recording head, and this back surface. A recording body is interposed between the electrode and the recording head, and liquid ink is supplied to the opening, and in this state, an electrical signal is output to the recording electrode, so that the recording is performed in response to the electrical signal. A surface coat made of an ink-phobic and highly insulating material is provided between the recording electrodes at the tip of the recording head, in which information is recorded by ejecting ink from the electrodes onto the recording medium. A recording device characterized by having a membrane selectively coated on the surface. (2) The recording device according to claim 1, wherein the surface coating film is oleophobic when the ink is oil-based, and hydrophobic when the ink is aqueous. (3) The recording device according to claim 2, wherein the oleophobic surface coating film is either a hydrogenated amorphous silicon nitride film or an amorphous silicon nitride film. (4) The surface coating film made of a hydrogenated amorphous silicon nitride film or an amorphous silicon nitride film is plasma etched by selectively masking a photoresist film on the hydrogenated amorphous silicon nitride film or amorphous silicon nitride film. 4. The recording device according to claim 3, wherein the surface of the recording electrodes is selectively coated between the recording electrodes. (5) A lower common electrode, a plurality of first recording electrodes electrically connected to the lower common electrode, and a predetermined minute gap between the first recording electrode and the insulating lower common electrode. and a photoelectric conversion member formed in a predetermined gap between the second recording electrode and the first recording electrode. an upper recording head section having an upper common electrode facing the second recording electrode with a minute gap on an insulating upper substrate facing the head section with a minute gap above the lower substrate; and a back electrode facing the tip of the lower recording head section, and a recording body is interposed between the back electrode and the lower recording head section, and a recording medium is provided between the lower and upper recording head sections. By supplying liquid ink to the minute gap between the two and inputting an optical image signal to the photoelectric conversion member in this state, the ink is transferred from the tip of the lower recording head section onto the recording medium in response to the optical image signal. In a device that records information by ejecting ink, zero from the tip of the lower recording head section.
．． A recording device characterized in that a surface coating film made of an ink-phobic and highly insulating material is selectively coated between the second recording electrodes having a thickness in the range of 0.05 mm to 2 mm. (6) The recording device according to claim 5, wherein the surface coating film is oleophobic when the ink is oil-based, and hydrophobic when the ink is aqueous. (7) The recording device according to claim 6, wherein the oleophobic surface coating film is either a hydrogenated amorphous silicon nitride film or an amorphous silicon nitride film. (8) The surface coating film made of a hydrogenated amorphous silicon nitride film or an amorphous silicon nitride film is plasma etched by selectively masking a photoresist film on the hydrogenated amorphous silicon nitride film or amorphous silicon nitride film. 8. The recording device according to claim 7, wherein the recording electrodes are selectively surface-coated between the recording electrodes.