JP3134548B2 - Electrostatic recording head and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording head, and more particularly, to an ion generating section comprising a discharge electrode, an insulating layer and an induction electrode, and an ion flow controlling section formed by a screen electrode. The present invention relates to an electrostatic recording head used for, for example, a printer or a facsimile.

[0002]

2. Description of the Related Art Conventionally, there has been known an electrostatic recording head which generates ions and records an image using the ions (see Japanese Patent Application Laid-Open No. 54-78134). As shown in FIGS. 3 and 4, the electrostatic recording head includes an induction electrode 02, a first insulation layer 03, and a discharge electrode 04 arranged so as to intersect the induction electrode 02, which are sequentially formed on an insulating substrate 01. ,
The second insulating layer 05 is provided. The second insulating layer 05 has a space region 06 for generating ions at the intersection of the discharge electrode 04 and the induction electrode 02. The intersections and the space areas 06 are arranged in a matrix (in a plan view) in FIG. On the insulating substrate 01, a screen electrode 07 is formed.
7, an opening 08 for ion passage is formed corresponding to the space area 06. An ion generation unit that generates ions in the space area 06 is configured by the elements indicated by the reference numerals 02 to 06 and the high-voltage power supply 020 that applies a high-frequency high voltage between the induction electrode 02 and the discharge electrode 04. The discharge electrode 04 is connected to an ion control power supply 21 for outputting a pulse-like ion flow control voltage for generating an ion flow control electric field between the discharge electrode 04 and the screen electrode 07. An ion flow control unit is composed of the ion control power supply 021 and the elements indicated by the reference numerals 04 to 07. The screen electrode 07 is connected to a DC power supply 022 for generating a bias potential for an electrostatic latent image carrier (dielectric drum) not shown.

In such an electrostatic recording head Ho, a corona discharge is generated in the space area 06, and ions generated by the corona discharge are accelerated or absorbed by an electric field between the discharge electrode 04 and the screen electrode 07. , Control of ion emission, and a latent image carrier (not shown)
An electrostatic latent image is formed thereon.

[0004]

Considering the material of the first insulating layer 03, the characteristics of organic polymer materials such as polyimide and Teflon deteriorate when exposed to discharge. Other than this, see, for example, JP-A-63-27015.
No. 4 discloses natural mica. However, this lacks stability. Japanese Patent Laid-Open No. 20357/1990 describes a ceramic such as alumina. However, the green sheet printing lamination method shrinks during firing, resulting in poor dimensional accuracy. In order to satisfy the characteristics as a head, there is a required dimensional accuracy. In order to obtain characteristics that meet the required quality and cost, it is proposed that the ion generating portion be formed by a thick film printing method. In this case, it is a simple method to form the insulating layer by printing and baking a glass paste.
However, it is known that an insulating film using glass has a low dielectric breakdown voltage due to the presence of pinholes and voids. This is considered to be because the voided film has a reduced effective thickness, and thus has a lower dielectric breakdown voltage. When such a film is used as the first insulating layer, there is a problem that breakdown occurs at an initial stage or at the time of operation of the head, thereby causing a failure of the head. The present invention has been made in view of the above circumstances, and has an object of the following content (A11). (A11) To provide an electrostatic recording head with improved reliability by increasing the dielectric breakdown voltage of a first insulating layer to which an AC high voltage is applied.

[0005]

Next, the present invention devised to solve the above-mentioned problems will be described. Elements of the present invention are used to facilitate correspondence with elements of the embodiments described later. , The reference numerals of the elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the following embodiments is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments. In order to solve the above problems, an electrostatic recording head (H) according to a first invention of the present application includes an induction electrode (2) extending in a predetermined direction, a first insulating layer made of glass (thick film printing method). 3) a discharge electrode (4) arranged to intersect the induction electrode (2), and a space region (6) for generating ions at an intersection of the discharge electrode (4) with the induction electrode (2). A second insulating layer (5) having the following, and a spatial region (6) for the ion generation:
In an electrostatic recording head (H) in which a screen electrode (7) having an opening (8) for ion passage corresponding to the above is provided in a laminated state on an insulating substrate (1), the following requirements (A1)
(A1) The first insulating film (3) is made of amorphous glass formed by firing a crystallized glass paste at a temperature lower than a crystallization temperature. .

Generally, in order to obtain a glass having less voids,
In this case, an amorphous glass may be used.
Reacts repeatedly with the conductor, adversely affecting the characteristics.
There are drawbacks. Also, commercially available amorphous glass paste is resistant to
In addition to mixing a thermal filler, a small amount of
Crystals may precipitate. The first insulating layer may be, for example,
If the glass composition is SiO_Two・ MgO ・ ZnO ・ Al_TwoO _Three
Having a transition point of 660 ° C, a softening point of 800 ° C,
Crystallized glass paste with a crystallization temperature of 850 ° C
Create by printing and baking. At this time, the firing peak temperature was set to 8
When the temperature is in the range of 00 to 850 ° C., the amorphous state can be obtained.
You. Ag, Ag / Pd, Ag / P
t, Au, Pt, Al, Cr, Ni, etc.
Alternatively, a resistor paste such as RuO2 can be selected.

Further, the method of manufacturing the electrostatic recording head (H) according to the second invention of the present application is directed to an induction electrode (2) extending in a predetermined direction, and a first insulating layer made of glass (thick film printing). 3) a discharge electrode (4) arranged to intersect the induction electrode (2), and a space region (6) for generating ions at an intersection of the discharge electrode (4) with the induction electrode (2). And a screen electrode (7) having an opening (8) for ion passage corresponding to the space region (6) for ion generation on the insulating substrate (1). In the method for manufacturing the formed electrostatic recording head (H), the following requirements (A2) and (A3) are provided.
(A2) when forming the first insulating layer (3), firing the crystallized glass paste at a temperature lower than the crystallization temperature; (A3) in the step after forming the first insulating layer (3); A processing temperature of the insulating substrate (1) is lower than a firing peak temperature of the first insulating layer.

[0008]

Next, the operation of the present invention having the above-mentioned features will be described. In the electrostatic recording head (H) according to the first invention of the present application having the above-described features, the first insulating layer (3) does not generate voids due to crystal grain boundaries generated when crystallizing, and is dense. It is a film

According to the method of manufacturing the electrostatic recording head (H) according to the second aspect of the present invention having the above-described features, the first insulating layer (3) is fired at a temperature lower than its crystallization temperature. Therefore, it is not crystallized immediately after its formation. Further, an insulating substrate (an insulating substrate on which a first insulating layer is formed) in a subsequent process
The processing temperature of (1) does not reach a temperature higher than the firing temperature of the first insulating layer (3). For this reason, it does not occur that the first insulating layer (3) is crystallized in a later step to generate voids.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. FIG. 1 is a sectional view of a principal part showing an embodiment of the electrostatic recording head of the present invention, and FIG. 2 is a partially cutaway plan view of the electrostatic recording head of the embodiment. In FIG. 1, “・” in “○” means an arrow heading from the back of the paper to the front, and “×” in “」 ”means an arrow on the paper. From the back to the back. The overall configuration of the electrostatic recording head H of this embodiment is substantially the same as the conventional electrostatic recording head Ho shown in FIG. In the description of the embodiment of the electrostatic recording head H shown in FIGS.
4, the components corresponding to those of the conventional electrostatic recording head shown in FIG. 4 are denoted by the same reference numerals except for the first 0 used in FIGS. 3 and 4, and detailed description of the overall configuration is omitted. .

In FIGS. 1 and 2, an electrostatic recording head H is
It has an insulating substrate 1 made of 96% alumina material. On the surface of the insulating substrate 1, an induction electrode 2 formed by a thick film printing method is formed. The induction electrode 2 is formed of an Ag / Pt alloy. Further, as can be seen from FIG. 2, a plurality of the induction electrodes 2 (five in this example) are formed. Each guide electrode 2 has a guide electrode body portion 2a and a guide electrode lead portion 2b (see FIG. 2) extending in the main scanning direction (the horizontal direction in FIGS. 1 and 2, ie, the direction indicated by arrow X) X. On the surface of the insulating substrate 1 on which the induction electrode 2 is formed,
A first insulating layer 3 made of glass is formed so as to cover the induction electrode body 2a. This first insulating layer 3 is shown in FIG.
As can be seen from FIG.

In FIG. 2, a plurality of Ni discharge electrodes 4 are formed on the surface of the first insulating layer 3. Each of the discharge electrodes 4 has a discharge electrode main body 4a, 4a and a discharge electrode lead portion 4b which are separated into two parts. The discharge electrode body 4
a and 4a are parallel, and are arranged so as to obliquely cross the induction electrode main body 2a extending in the main scanning direction. On the surface of the insulating substrate 1 on which the plurality of discharge electrodes 4 are formed, a second insulating layer 5 made of glass is formed. As can be seen from FIGS. 1 and 2, this second insulating layer 5
Are disposed so as to form a discharge space 6 between the pair of discharge electrode main bodies 4a, 4a. On the surface of the insulating substrate 1 on which the second insulating layer 5 is formed, a screen electrode 7 using a stainless steel foil having a thickness of 30 μm is formed. The screen electrode 7 has openings 8 corresponding to the discharge spaces 6 and the dielectric electrode body 2a. The discharge space 6 and the openings 8 are arranged in a matrix. The electrostatic recording head H according to the present embodiment includes the elements indicated by the reference numerals 1 to 8.

In FIG. 1, an AC power supply 20 of high frequency and high voltage is provided between the induction electrode 2 and the screen electrode 7, and an ion control power supply for outputting a pulsed ion flow control voltage to the discharge electrode 4. 21 are connected. The screen electrode 7 is connected to an electrostatic latent image carrier 23 via a DC power supply 22. Electrostatic latent image carrier 2
3 is arranged at a position facing the opening 8 of the screen electrode 7 When a high-frequency high voltage of the AC power supply 20 is applied, a creeping corona discharge occurs in the discharge space 6, and ions are generated by the creeping corona discharge. appear.

An electric field corresponding to the ion flow control voltage is generated between the discharge electrode 4 and the screen electrode 7.
Due to this electric field, ions generated by the creeping corona discharge are accelerated and travel toward the electrostatic latent image carrier 23 through the opening 8 or are absorbed by the screen electrode 7. The ions passing through the opening 8 form an electrostatic latent image on the electrostatic latent image carrier 23.

The first insulating layer 3 is formed by firing a crystallized glass paste at a peak temperature of 800 ° C. At this time, the fired film thickness of the first insulating layer 3 is 25 μm. Thereafter, the discharge electrode 4 and the second insulating layer 5 have a peak temperature of 650 °.
C. (that is, the temperature is 800 ° C. or less). Then, the first insulating layer 3 is a film having no voids due to crystal grain boundaries. Even when a voltage of 1 kVp was applied from the AC power supply 20 at 1 MHz to the thus-formed electrostatic recording head H, the first insulating layer did not cause initial dielectric breakdown. Further, even if the electrostatic latent image recording head H is actually used to form an electrostatic latent image on the electrostatic latent image carrier (dielectric drum) 23, the failure of the first insulating layer 3 occurs. Did not.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. For example, the peak temperature, the fired film thickness, and the like at the time of firing the first insulating layer 3 are not limited to the values shown in the examples, and various values may be adopted within the scope of the present invention. It is possible. Various values can also be adopted for the peak temperature at the time of firing the discharge electrode 4 and the second insulating layer 5 within the range of the peak temperature at the time of firing the first insulating layer 3.

[0017]

As described above, in the electrostatic recording head according to the first aspect of the present invention, the first insulating layer is a film free from voids due to crystal grain boundaries. For this reason, it is possible to use a stable and highly reliable head for a long period of time without causing dielectric breakdown of the first insulating layer at the initial stage and during use.
According to the method for manufacturing an electrostatic recording head of the second invention of the present application, a highly reliable electrostatic recording head can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an electrostatic recording head according to the present invention.

FIG. 2 is a partially cutaway plan view of the electrostatic recording head of the embodiment.

FIG. 3 is a sectional view showing a conventional electrostatic recording head.

FIG. 4 is a partially cutaway plan view of the head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating substrate, 2 ... Induction electrode, 3 ... First insulating layer, 4 ... Discharge electrode, 5 ... Second insulating layer, 6 ... Space area for ion generation, 7 ... Screen electrode, 8 ... Opening

Continuing from the front page (72) Inventor Tetsuo Yamada 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Koji Udagawa 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (56) References Kaihei 4-353475 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/415 G03G 15/05 H04N 1/032

Claims (2)

(57) [Claims] 1. An induction electrode extending in a predetermined direction, a first insulating layer made of glass manufactured by a thick-film printing method, a discharge electrode arranged to intersect the induction electrode, and an induction electrode of the discharge electrode. A second insulating layer having a space region for ion generation at the intersection of the above, and a screen electrode having an opening for ion passage corresponding to the space region for ion generation are provided in a laminated state on the insulating substrate. The electrostatic recording head, which satisfies the following requirement (A1): (A1) The first insulating film is formed by firing a crystallized glass paste at a temperature lower than a crystallization temperature. It is composed of the formed amorphous glass. 2. An induction electrode extending in a predetermined direction, a first insulating layer made of glass manufactured by a thick-film printing method, a discharge electrode arranged to intersect the induction electrode, and an induction electrode of the discharge electrode. A second insulating layer having an ion-generating space region at the intersection of the electrodes, and a screen electrode having an ion-passing opening corresponding to the ion-generating space region is sequentially formed on an insulating substrate. In the method for manufacturing a recording head, the following requirements (A2) and (A3) are provided, (A2) the first method:
When forming the insulating layer (3), firing the crystallized glass paste at a temperature lower than the crystallization temperature; (A3) the insulating substrate (1) in the step after forming the first insulating layer (3); A temperature lower than the firing peak temperature of the first insulating layer.