JPH0679911A - Ion flow type electrostatic recording head - Google Patents

Abstract

PURPOSE:To tightly fix a portion between two kinds of electrodes and a dielectric layer by forming the electrodes with hardened members made of electrically conductive paste hardened under heating, and make it possible to hardly cause deviation of the positions among the electrodes due to thermal and mechanical loads at the time of after-machining and even in the case of thermal change with time during the use of a recording head. CONSTITUTION:A dielectric layer 4 is provided on the surface side of an insulating base plate 2, where first electrodes 3... are provided in parallel with one another, in such a state that these first electrodes 3... are embedded in said dielectric layer. A plurality of second electrodes 5... which are discharge electrodes, are fixed on the surface of the dielectric layer 4. These first and second electrodes 3..., 5... are respectively formed of thermally hardened members made by hardening electrically conductive paste under heating. Further, a plurality of second electrodes 5... disposed on the dielectric layer 4 are arranged on its surface opposite to the face on which it is in contact with the insulating base plate 2, and are provided in parallel with one another in a direction in which they intersect with the first electrodes 3..., thus a matrix is constituted of the first electrodes 3... and the second electrodes 5....

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion flow electrostatic recording head of an electrostatic recording device used for electrostatic printing or copying.

[0002]

2. Description of the Related Art Generally, for example, in electrostatic printing, ions of high current density are generated, and the ions are extracted and selectively applied to a member to be charged, and the member to be charged is imagewise charged. Electronic recording devices are known.

An ion flow electrostatic recording head used in this electrostatic recording apparatus is fixed to a dielectric layer and one surface of the dielectric layer, a plurality of first electrodes extending in a first direction, and the dielectric layer. A plurality of second electrodes fixed to the other surface of the first electrode and extending in a direction intersecting with the extension direction of the first electrode, and the plurality of first electrodes and the plurality of second electrodes form a matrix.
Then, an opening for ion generation is formed in a portion of the second electrode corresponding to the matrix.

A third electrode is provided on the opposite side of the second electrode from the first electrode. An insulator layer is arranged between the third electrode and the second electrode. Openings corresponding to the openings of the second electrode are formed in these insulator layers and the third electrode, and the ion flow passage openings are formed by these openings.

Then, a high voltage is alternately applied between the first electrode and the second electrode corresponding to the selected portion of the matrix between the first electrode and the second electrode so as to face that portion. Positive and negative ions are generated near the opening of the second electrode.

Further, a bias voltage is applied between the second electrode and the third electrode, and only ions determined by the polarity thereof are selectively extracted from the generated ions, pass through the ion flow passage opening, and pass through the third electrode. The member to be charged, which is arranged so as to face the electrode, can be partially charged. Therefore, electrostatic recording by dots can be performed by selectively driving the electrodes having the matrix structure.

The dielectric material forming the dielectric layer used here is required not to cause dielectric breakdown even at a high voltage applied for ion generation. Further, since the dielectric layer needs to have a thickness that efficiently generates ions and can withstand dielectric breakdown, a layer having a high dielectric constant is suitable.

Therefore, as a material of the dielectric layer of the ion flow electrostatic recording head, for example, Japanese Patent Application Laid-Open No. 2-153760 discloses a material in which titanium oxide powder is mixed in a silicone-modified polyester alkyd resin.

A foil of stainless steel is used as the material of the second electrode. When the second electrode is fixed to the dielectric layer, a silicone pressure sensitive adhesive is used.

[0010]

Generally, in the manufacturing process of an ion flow electrostatic recording head, there are a heating process and a mechanical bending process as post-processings of the fixing process for fixing the second electrode to the dielectric layer. The entire print head generates heat when the print head is used. The generation of stress in these thermal and mechanical materials concentrates on the portion having the weakest cohesive force, for example, the fixed portion between the second electrode of the recording head and the dielectric layer.

Here, a silicone-based pressure-sensitive adhesive used for fixing the second electrode to the dielectric layer (Japanese Patent Laid-Open No. 2-1537).
No. 60) is strong in peeling force but weak in shearing force. Therefore, when fixing the second electrode to the dielectric layer,
When the silicone pressure-sensitive adhesive disclosed in JP-A-2-153760 is used, a heating step after the fixing step of fixing the electrode to the dielectric layer, a mechanical bending step, or There is a problem that the recording head cannot sufficiently withstand heat during use or shear force due to mechanical stress. Therefore, after the electrodes are fixed, a gap may occur between the first electrode and the second electrode, and the image quality may deteriorate.

Further, the adhesion area of each second electrode to the surface of the dielectric layer is a minute area of about several square millimeters. Therefore, this small area can be
A structure that is fixed so that there is no misalignment between the electrode and the surface of the dielectric layer, and that withstands thermal and mechanical loads during post-processing and thermal aging during use of the recording head. In order to do so, it is necessary to use an adhesive having a strong adhesive force, so there is a problem that the cost becomes high.

Since the second electrode is formed with several thousands of small holes for ion generation having a hole diameter of the order of 100 μm, an adhesive is selectively applied to a portion other than the small holes to bond them. It is extremely difficult to do. Therefore, after the second electrode and the dielectric layer are bonded together, the part where the second electrode and the dielectric layer are bonded is washed to remove excess adhesive in the opening corresponding to the small hole. There is a problem that various cleaning work is required.

Furthermore, during this cleaning operation, it is difficult to remove all the adhesive agent that has adhered to the openings of the thousands of small holes formed in the second electrode. The adhesive may remain locally in the openings of the two electrodes, and the necessary adhesive may be peeled off at the periphery of the openings of the second electrode on the side of the bonding surface with the dielectric layer, so that the metal surface may be removed. There is also the possibility that some places will be exposed. In this case, since the current density contributing to the discharge is different between the exposed part of the metal surface and the part covered with the adhesive, the amount of ions generated in each opening varies, and it is difficult to obtain uniform image quality and durability. Becomes

Further, a high etching technique is required to provide a large number of small holes in the order of several thousand in the stainless steel foil, which are in the order of several thousand, with a high degree of accuracy, and therefore there is a problem of high cost.

The present invention has been made in view of the above circumstances, and an object thereof is to firmly fix the second electrode and the dielectric layer to each other, and to obtain thermal and mechanical properties during post-processing. Displacement can be made less likely to occur between the electrodes even under various loads and thermal aging during use, and the amount of ions generated in each opening of the second electrode can be made uniform to improve image quality and durability. An object of the present invention is to provide an ion flow electrostatic recording head that is improved and is inexpensive.

[0017]

According to a first aspect of the present invention, a plurality of first electrodes are provided in parallel on one side of a dielectric layer, and the first electrodes are provided on the other side of the dielectric layer. In an ion flow electrostatic recording head in which a matrix-shaped ion generating section is formed by a plurality of second electrodes arranged in parallel in different directions, the electrodes are heated by heating and curing a conductive paste. It is formed by a cured body.

According to a second aspect of the present invention, a plurality of first electrodes are arranged in parallel on one surface side of the dielectric layer, and a plurality of first electrodes are arranged on the other surface side of the dielectric layer in a direction different from the first electrode. In an ion flow electrostatic recording head in which a matrix-shaped ion generating portion is formed by a plurality of second electrodes arranged in parallel, the second electrode is formed by a heat-cured body obtained by heat-curing a conductive paste. It was formed.

[0019]

According to the present invention, the electrodes are formed by a heat-cured material obtained by heat-curing a conductive paste, so that the surface of the dielectric layer can be treated without using an adhesive during the work of fixing the dielectric layer and the electrodes. Directly apply conductive paste to
This is to fix the dielectric layer and the electrode at the same time when the electrode is formed by curing.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. 1A and 1B show a schematic configuration of an ion flow electrostatic recording head 1 of an electrostatic recording apparatus, and 2 is an insulating substrate of the ion flow electrostatic recording head 1.

On the insulating substrate 2 are provided a plurality of first electrodes 3 ... Which are induction electrodes for ion generation. The plurality of first electrodes 3 ... Are arranged in parallel in one direction.

Further, a dielectric layer 4 is provided on the insulating substrate 2 on the side where the first electrodes 3 are juxtaposed so that the first electrodes 3 are embedded. On the surface of this dielectric layer 4, a plurality of second electrodes 5 ... Are fixed as discharge electrodes. The first and second electrodes 3, ..., 5 ... Are each formed of a heat-cured body obtained by heat-curing a conductive paste.

Further, the plurality of second electrodes 5 ... Are the dielectric layers 4
Are arranged on a surface opposite to the insulating substrate 2 and are arranged in parallel in a direction intersecting with the first electrodes 3 ...
And the second electrode 5 ... Form a matrix. Further, the second electrodes 5 ... Are respectively formed with the openings 5a for ion generation at the portions corresponding to this matrix.

Further, an insulator layer 6 is provided on the side of the dielectric layer 4 on which the second electrodes 5 are juxtaposed so that the second electrodes 5 are embedded therein. Openings 6a are formed in the insulating layer 6 at positions corresponding to the openings 5a of the second electrodes 5.

Further, the surface of the insulator layer 6 has a third strip-like shape.
An electrode 7 is provided. The third electrode 7 is provided with openings 7a ... In a portion corresponding to the matrix of the first electrode 3 ... And the second electrode 5. The openings 7a of the third electrode 7 are the openings 6a of the insulator layer 6 and the second electrode 5.
The ion flow passage ports 8 of the ion flow electrostatic recording head 1 are formed in communication with the openings 5a of.

During operation of the ion flow electrostatic recording head 1, the matrix between the first electrodes 3 ... And the second electrodes 5 ... Is appropriately selected based on the print signal, and the matrix corresponding to the selected matrix portion is selected. An alternating voltage is applied between the first electrode 3 and the second electrode 5.

As a result, positive / negative ions are generated in the vicinity of the openings 5a ... Of the second electrodes 5 ... Corresponding to the selected matrix portion. At this time, a bias voltage is applied between the second electrode 5 ... And the third electrode 7, and only the ions determined by the polarity thereof are in the openings 5a of the second electrode 5.
It is extracted from the ions generated in the vicinity of the inside.

Then, the extracted ions pass through the opening 6a of the insulator layer 6 and the opening 7a of the third electrode 7,
A dielectric drum (not shown) is locally charged. Therefore, a dot latent image can be formed on the dielectric drum by selectively driving the first electrodes 3 and the second electrodes 5.

Next, a method of manufacturing the ion flow electrostatic recording head 1 shown in FIGS. 1A and 1B will be described in detail.
First, the first electrodes 3 ... Are formed on the insulating substrate 2. In this case, the insulating substrate 2 is, for example, a sheet-like hybrid I having a thickness of 100 μm and a surface coated with amorphous glass.
It is a 96% alumina glaze substrate for C.

The first electrodes 3 ... Are conductive pastes,
For example, "High conductivity silver-platinum conductive paste TR-3913" made by Tanaka Kikinzoku International (trade name)
Is formed by a heat-cured body obtained by heat-curing.

At the time of molding the first electrodes 3, ..., A conductive paste is printed in a predetermined pattern on the sheet surface on one side of the insulating substrate 2 by using a 200-mesh screen plate in which an emulsion is formed in a thickness of 12 μm. Furthermore, after printing, after leveling at room temperature for 10 minutes, at 120 ° C,
After drying for 10 minutes, the temperature was raised to 850 ° C. in 5 minutes, held for 10 minutes, and gradually cooled to obtain a thickness of 9
.mu.m first electrodes 3 ... Are formed.

After forming the first electrodes 3 on the insulating substrate 2, the dielectric layer 4 is formed between the patterns of the first electrodes 3 on the insulating substrate 2 and on the first electrodes 3 as shown in FIG. Is formed. At the time of forming the dielectric layer 4, first, a dielectric paste made of an amorphous ceramic binder, for example, "PLS-3123" (trade name) manufactured by Nippon Electric Glass Co., is applied onto the insulating substrate 2.

Further, after the dielectric paste applied on the insulating substrate 2 is dried at 150 ° C. for 10 minutes, 30 ° C. /
The temperature is raised to 520 ° C. at a temperature raising rate of min. After being kept in this state for 5 minutes, the temperature is then lowered at 50 ° C./min to be cured and fired to form a dielectric layer 4 having a thickness of 33 μm on the first electrodes 3.

Then, the second electrodes 5 are fixed on the surface of the dielectric layer 4. The second electrodes 5 ... Are the first electrodes 3
Similarly, a conductive paste, for example, a high-conductivity silver-platinum-based conductive paste TR-3913 (trade name) manufactured by Tanaka Kikinzoku International Co., Ltd. (trade name) is heat-cured to form a heat-cured body.

At the time of molding the second electrodes 5, ... A predetermined electrode pattern (second electrodes 5 ... And the openings 5 of each second electrode 5).
The conductive paste is screen-printed on the surface of the dielectric layer 4 using a 400-mesh screen plate manufactured by forming the electrode pattern a) with a photosensitive emulsion. Here, the openings 5a ... Of the electrode pattern screen-printed on the surface of the dielectric layer 4 are the plurality of first electrodes 3.
Aligned to ... Subsequently, the screen-printed conductive paste is cured under the same curing conditions as when forming the first electrodes 3 ..., Thus, the second electrodes 5 ... With a thickness of 9 μm are formed.

Next, the first electrodes 3 on the insulating substrate 2 ...
A photosensitive insulating film (solder resist) is vacuum-laminated on the laminated body of the dielectric layer 4 and the second electrode 5 ...
The insulator layer 6 is formed. After that, this insulating film is subjected to photoetching treatment such as exposure and development in the same manner as a normal photosensitive film, and an opening 6a for passing an ion flow corresponding to the openings 5a of the plurality of second electrodes 5 is formed. ... is formed.

Next, on the insulating layer 6 thus formed, a stainless foil having a thickness of, for example, about 30 μm is formed with openings 7a corresponding to the openings 5a of the second electrodes 5. The three electrodes 8 are joined by means such as adhesion. In this case, the ion flow electrostatic recording head 1 is manufactured by positioning and overlapping the third electrode 7 with the openings 7a ... Corresponding to the openings 5a. . The insulator layer 6 and the third electrode 7 may be attached to the insulator layer 6 with a single-sided tape, instead of being attached with an adhesive or a double-sided tape.

Therefore, in the above-mentioned structure, since the first electrode 3 and the second electrode 5 are formed by the heat-cured body obtained by heat-curing the conductive paste, the first electrode 3 is formed.
The first electrode 3 is directly applied onto the insulating substrate 2 during the forming operation, and the insulating substrate 2 and the first electrode 3 can be fixed at the same time when the electrode is formed by curing the electrode. Similarly, at the time of forming the second electrodes 5 ...
It is possible to fix the dielectric layer 4 and the second electrodes 5 at the same time when the electrodes are formed by directly applying the second electrodes 5 ...

Therefore, it is possible to fix the insulating substrate 2 and the first electrode 3 ... and the dielectric layer 4 and the second electrode 5 ... As described above, the adhesive remains in the openings 5a of the second electrodes 5, or the second electrode on the side of the first electrodes 3 around the openings 5a when the adhesive in the openings 5a is washed and removed. There is no possibility that the metal surface will be exposed on the surface of the electrodes 5 ..., and the current density that contributes to discharge will not differ for each opening 5a of the second electrodes 5.

Since each electrode can be fixed more firmly than the conventional pressure sensitive adhesive of silicone type,
During the manufacturing process of the recording head 1, the first electrode is used for the thermal and mechanical load acting on the fixing portion of each electrode in the post-processing after the fixing of each electrode, and the thermal aging change during use of the recording head 1. It is possible to prevent the positional deviation between 3 ... and the second electrodes 5 ... As a result, the amount of discharge ions from each opening 5a of the second electrode 5 can be made uniform, so that the image quality can be improved and the durability can be improved.

Further, since the second electrodes 5 and their openings 5a are formed on the surface of the dielectric layer 4 by screen printing, the second electrodes 5 and their openings are highly accurately formed on the stainless steel foil by an etching technique. Cost can be reduced as compared with the case of forming 5a ....

The present invention is not limited to the above embodiment. For example, when the second electrode 5 is formed on the surface of the dielectric layer 4 of the ion flow electrostatic recording head 1 as in the second embodiment of the present invention, a conductive paste “Noritake Co.” is used as a conductive paste. Gold-based resinate paste D-2
You may use 0 (brand name).

At the time of molding the second electrodes 5, ..., A conductive paste is screen-printed on the surface of the dielectric layer 4 as in the first embodiment. Then, in the step of hardening and firing the conductive paste of the present embodiment, the temperature is raised to 600 ° C. in 5 minutes, held there for 5 minutes, and then cooled to room temperature in 10 minutes. The thickness of the second electrodes 5 obtained through the curing and firing process of the conductive paste is 0.3 μm.

Even with the above structure, the same effect as that of the first embodiment can be obtained, and by using the resinate type conductive paste as in the present embodiment, the second electrode 5 can be obtained. It is possible to make a fine pattern.

Further, as in the third embodiment of the present invention, a second layer is formed on the surface of the dielectric layer 4 of the ion flow electrostatic recording head 1.
When forming the electrodes 5 ..., “Shintron K-3424” (trade name), which is a silver-epoxy conductive paste made by Shinto Chemitron, may be used as the conductive paste.

At the time of molding the second electrodes 5, ..., A conductive paste is screen-printed on the surface of the dielectric layer 4 as in the first embodiment. The conductive paste of this embodiment is cured at 150 ° C. for 60 minutes at a low temperature for a short time.
Second electrode 5 obtained by curing the conductive paste ...
Has a thickness of 15 μm. Even with the above structure, the same effect as that of the first embodiment can be obtained.

The dielectric layer 4 of the ion flow electrostatic recording head 1 is a paste in which dielectric powder, for example, inorganic powder having a large dielectric constant is dispersed in an organic polymer material containing a solvent or a ceramic binder. It is also possible to use a product obtained by coating the insulating substrate 2 on the insulating substrate 2 and then drying and curing the same.

Here, as the dielectric powder of the dielectric layer 4, for example, titanium oxide, barium titanate, lead zirconate or the like can be used. Further, as the organic polymer material, a material obtained by dissolving a resin component such as a thermosetting alkyd resin or an epoxy resin in an organic solvent can be used, and as the ceramic-based binder, low melting point glass or the like can be used.

Further, as means for forming the second electrodes 5 ... On the dielectric layer 4, a conductive paste is screen-printed on the dielectric layer 4 in a predetermined pattern, or is applied by a method such as transfer. Good. In this case as well, after the conductive paste is applied, the solvent is dried and removed to be cured by heating.

As the conductive paste to be used, carbon black, silver, copper, nickel or the like, which is a single product or a composite powder, is dispersed as a conductive filler in various resins such as epoxy resin and acrylic resin. Other than
A paste containing an organic metal compound such as a resinate paste or a metal organic deposition paste can also be used.

However, when a conductive paste such as a resinate paste or a metal organic deposition paste is used, the curing and firing temperature is 500 ° C. or higher, which is higher than that of a normal conductive paste, so that the first electrodes 3 are laminated. It is necessary to use a glass substrate or a ceramic substrate such as alumina as a material for the insulating substrate 2 and a ceramic system having high heat resistance as a material for the dielectric layer 4. In addition,
Needless to say, various modifications can be made without departing from the scope of the present invention.

[0052]

According to the present invention, since the electrode is formed by the heat-cured body obtained by heat-curing the conductive paste, the second electrode and the dielectric layer can be firmly fixed to each other. Positional displacement between electrodes can be made less likely to occur due to thermal and mechanical loads during processing and thermal aging during use, and the amount of ions generated in each opening of the second electrode can be made uniform. It is possible to improve the image quality, improve the durability, and reduce the cost.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention (A)
Is a longitudinal sectional view of a main part showing a schematic configuration of an ion flow electrostatic recording head, and FIG.

FIG. 2 is a vertical cross-sectional view of a main part showing a state in which a dielectric layer is laminated on a first electrode and an insulating substrate.

FIG. 3 is a vertical cross-sectional view of a main part showing a state in which a second electrode is fixed on a dielectric layer.

[Explanation of symbols]

2 ... Insulating substrate, 3 ... First electrode, 4 ... Dielectric layer, 5 ... Second
electrode.

Claims (2)

[Claims] 1. A plurality of first electrodes arranged substantially parallel to one surface side of a dielectric layer, and a plurality of first electrodes arranged substantially parallel to the other surface side of the dielectric layer in a direction different from the first electrode. Multiple second
An ion flow electrostatic recording head in which a matrix-shaped ion generating portion is formed by electrodes, wherein the electrodes are formed by a heat-cured body obtained by heat-curing a conductive paste. . 2. A plurality of first electrodes arranged substantially parallel to one surface side of the dielectric layer, and a plurality of first electrodes arranged substantially parallel to the other surface side of the dielectric layer in a direction different from the first electrode. Multiple second
In an ion flow electrostatic recording head in which a matrix-shaped ion generating portion is formed by electrodes, the second electrode is formed by a heat-cured body obtained by heat-curing a conductive paste. Electric recording head.