JPH02120766A - Electrostatic latent image forming device - Google Patents

Abstract

PURPOSE:To prevent erroneous discharging from occurring so as not to cause noises, etc., by providing an electrode for preventing mutual induction and preventing the mutual induction from occurring between 1st electrodes opposed to a 2nd electrode by putting an insulating substrate between them. CONSTITUTION:In a recording head, the electrode for preventing mutual induction which is stretched over all the surface is provided besides the driving electrode 3 being the 1st electrode in a matrix array and the control electrode 5 being the 2nd electrode which put the insulating layer 4 between them. By impressing an AC voltage between the electrodes 3 and 5, corona discharging occurs and an electrostatic latent image is formed. In such a case, the occurrence of the mutual induction between the electrodes 3 is prevented by the electrode 12. An electrostatic latent image forming device where the erroneous discharging is prevented from occurring and the noises by the erroneous discharging is not caused is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention applies to electrostatics used in electrostatic recording. The present invention relates to an apparatus for forming an m-image, and specifically relates to an electrostatic latent image forming apparatus using ion flow control.

[Prior Art] Conventionally, this type of electrostatic latent image forming apparatus includes the following. As shown in FIGS. 7 to 9-9, a plurality of drive electrodes 51, 51...
are provided in parallel to each other, and these drive electrodes 51
．． A plurality of control electrodes 54, 54... are provided on the drive electrodes 51.
51... and control electrodes 54, 54... form a matrix. In addition, the control l electrode 5'4.54...
* is formed by arranging two thin electrodes 55.55 parallel to each other, and a space region 56 for ion generation is provided between both electrodes 55.55. Furthermore, the control electrode 54.5
4... A flat screen electrode 58 is provided on the top with an insulating layer 57 interposed therebetween.
As shown in the figure, circular openings 59, 59, . . . for ion extraction are provided at the intersections of the drive type 1 (i51, 51, . Medium, 6
0 indicates a frontage provided in the insulating layer 57.

As shown in FIG. 9, the electrostatic latent image forming device has drive electrodes 51, 51, . . . and control electrodes 54, 54, .
A high frequency high voltage is applied between the control electrodes 54, 54, . . . and a DC voltage is applied to the screen electrode 58, respectively.

By doing so, a creeping corona discharge is generated in the spatial region 56 between the drive electrode 51 and the control electrode 54, and ions generated by this creeping corona discharge are accelerated or accelerated by the electric field between the control electrode 54 and the screen electrode 58. It absorbs ions, controls ion release, and forms an electrostatic latent image.

[Problems to be Solved by the Invention] However, the above prior art has the following problems. That is, the drive electrodes 51, 51...
As shown in FIG. 8, the drive electrodes 51 and 51 are arranged parallel to each other at predetermined intervals, and an insulating layer
2 is interposed. Therefore, when a high frequency and high voltage is applied to the drive electrode 51 when generating ions, mutual induction depending on the capacitance between the adjacent drive electrodes 51, 51, etc. occurs, and the adjacent drive electrodes 51, 51...
A voltage is induced in Therefore, adjacent drive electrodes 5
1.51..., there was a problem in that extra discharge occurred and noise was generated.

[Means for Solving the Problems] Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and its purpose is to improve mutual communication between first electrodes corresponding to drive electrodes. It is an object of the present invention to provide an electrostatic latent image forming device that prevents induction from occurring and does not generate noise or the like.

That is, the present invention includes a plurality of first electrodes, a plurality of second electrodes, and an insulating substrate, and the first electrode and
The second electrodes are provided in a matrix shape with the insulating U-plate in between, and the second electrodes are provided with a creeping surface by applying an alternating current voltage between the first electrode and the second electrode. In an electrostatic latent image forming apparatus having a spatial region in which Rona discharge is generated, a mutual induction prevention electrode is provided to prevent mutual induction between the plurality of first electrodes.

The above-mentioned mutual induction prevention electrode is, for example, a plurality of first
is uniformly provided over the entire surface of the electrode with an insulating layer interposed therebetween.

Further, the mutual induction prevention electrode may be provided only at a position corresponding to the plurality of first electrodes with an insulating layer interposed therebetween.

Further, the mutual induction prevention electrode may be provided between adjacent first electrodes.

Further, the mutual induction prevention electrode may be grounded or floating, or a predetermined voltage may be applied as necessary.

[Function] In this invention, the first
This prevents mutual induction from occurring between the electrodes of the predetermined first
When an alternating current voltage is applied to the first electrode, voltage is prevented from being induced in the adjacent first electrode, thereby preventing erroneous discharge from occurring.

[Example] The present invention will be explained below based on illustrated embodiments.

FIG. 3 shows an embodiment of an electrostatic latent image forming apparatus according to the present invention. In the figure, reference numeral 1 denotes a recording head as an electrostatic latent image forming device, and this recording head 1 includes an insulating substrate 2 having a rectangular planar shape and made of a ceramic substrate such as alumina. On the surface of this insulating substrate 2, a plurality of drive electrodes 3a, 3b, 3C, . The ends of the drive electrodes 3a, 3b, 3c, . . . are bent toward both ends in the width direction of the insulating substrate 2. The drive electrode 3a.

3b, 3C..., as shown in FIGS. 1 and 2,
It is formed by pattern printing a metal such as tungsten on an insulating layer 13, which will be described later, using a screen printing method or the like. Drive electrodes 3a, 3b.

The thickness of 3C... is set to 5 to 40 μm, more preferably 10 to 20 μm. Further, the distance between the drive electrodes 3a, 3b, 3c... is 100 to 50
The thickness is set to 0 μm, preferably 200 to 300 μm.

An insulating layer 4 made of a green sheet, which is a ceramic sheet such as alumina, is laminated on the drive electrodes 3a, 3b, 3c, etc., and the thickness of the insulating layer 4 is 10 to 50 μm.
1 is preferably set to 20 to 30 μm.

On this insulating layer 4, drive electrodes 3a and 3b are provided.

Control electrodes 5a, 5b, 5c, . . . are provided so as to intersect with 3C, . . . at a predetermined angle. These control type Mi 5a, 5b, 5C, . . . are formed by pattern printing a metal such as tungsten using a screen printing method or the like. Control electrodes 5a, 5b, 5
The thickness of G... is the drive electrode 3a, 3b, 3C...
Similarly, it is set to 5 to 40 μm, more preferably 10 to 40 μm.
It is set to 20 μm.

The control electrodes 5a, 5b, 5c..., as shown in FIG. 3, have two thin electrodes 6.6 arranged parallel to each other,
A space region 7 for ion generation is formed between the picture electrodes 6.6, and one end 8 of both types 14i6.6 is formed.
are connected to each other in a U-shape to form a planar approximately tuning fork shape. Further, the control electrodes 5a, 5b, 5c, . . . are arranged such that their U-shaped connection portions 8, 8, . ing.

the above! As shown in FIGS. 1 and 2, an insulating layer 9 made of a green sheet, which is a ceramic sheet of alumina, etc., is laminated on the II m electrodes 5a, 5b, 5 cm. is formed by a screen printing method or the like. The thickness of the insulating layer 9 is 30 to 30
The thickness is set to 0 μm, preferably 50 to 100 μm.

The recording head 1 configured as described above includes an insulating substrate 2, each electrode 3a13b, 3C...5a, 5b, 5
C..., the materials forming the insulating layer 4.9, etc. are fired at high temperature to perform metallization (integral firing).

A screen electrode 10 is laminated on the surface of the insulating layer 9, and the screen electrode 10 is formed of a metal plate such as stainless steel.

The screen electrode 10 includes a driving electrode 3. a,,3b
, 3c... and the control electrodes 5a, 5b, 5C... intersect with the ion emitting openings 11, 11...
is drilled in a circular shape. During this time, the mouth part 11.11・
The diameter of . . . is set equal to the width of the spatial region 7 of the − control electrode 5, for example. The thickness of the screen electrode 10 is set to 5 to 40 μm similarly to the drive electrodes 3a13b, 3c, etc., and more preferably set to 10 to 20 μm. In FIG. 4, reference numeral 21 indicates an opening formed in the insulating layer 9. As shown in FIG.

By the way, in this embodiment, a mutual dielectric prevention electrode is provided to prevent mutual induction between the plurality of first electrodes. In addition, on the surface of the insulating substrate 2, as shown in FIGS. 1 and 2, a mutual induction prevention electrode 12 is formed to have a uniform thickness over the entire surface.

The mutual induction prevention electrode 12 is formed by printing a metal such as tungsten on the insulating substrate 2 to a uniform thickness over the entire surface by screen printing or the like.

The thickness of the mutual induction prevention electrode 12 is set to 5 to 40 μm, more preferably 10 to 20 μm.

Further, on the mutual induction prevention electrode 12, an insulating layer 13 made of a green sheet, which is a ceramic sheet such as alumina, is laminated. As shown in FIG. 1, the thickness d of the insulating layer 13, the material of which the insulating layer 13 is formed, and the electrical constant ε of the drive electrode 3a.

3b13c... and the electrostatic charge 8 in the region A where the mutual induction prevention electrode 12 overlaps with the adjacent drive electrode 3a.

3b, 3C... Capacity of open area B is C8, drive electrode 3a
, 3b, 3cm... and control electric Ji 5 a, 5b, 5c
If the capacitance of the overlapping region C is C6, then the drive voltage is
J Electric 14i3a, 3b, 3c--mutual M 3'J
In order to prevent this and cause creeping corona discharge between the drive electrodes 3a, 3b, 3C, . . . and the control electrodes 5a, 5b, 5C, . . ., C>C>CB is selected. A: As is well known, the capacitance C is given by ε·S/d. Here, S is the area of the opposing J6 electrode.

In this embodiment, the thickness of the insulating layer 13 is set to be the same as that of the insulating layer 4, <10 to 5.0 μm, preferably 20 to 30 μm.

Further, the mutual induction prevention electrode 12 is grounded, so that a shielding effect can be obtained on the back side of the insulating substrate 2. The mutual Ml prevention electrode 12 may be applied with a predetermined voltage instead of being grounded. When calculating the capacitance between the drive electrodes 3a, 3b, 3C, . . . and the mutual induction prevention electrode 13 and the control electrodes 5a, 5b, 5c, . . . , 3b, 3
Since we are considering a state in which a predetermined voltage is applied only to G... and the mutual induction prevention electrode 13 and the control electrodes 5a, 5b, 5C... are held at Ov, the mutual induction prevention electrode 13
In order to maintain the voltage at the same potential as the control electrode 5, a voltage similar to the bias voltage applied to the control electrode 5 may be applied to the mutual induction prevention electrode 13 as described later. In such a case, the relationship of capacitance between the electrodes can be maintained approximately equal to the predetermined set value.

By the way, as shown in FIG. 4, the recording head 1 has drive electrodes 3a, 3b, 3c, etc. and a screen electrode 1.
0, a high frequency high voltage is applied by an AC power supply 15, an ion control voltage is applied to the control electrodes 5a, 5b, 5c, etc. by an ion control power supply 16 and a bias power supply 17, and an ion control voltage is applied to the screen electrode 10 by a power supply 18. Apply DC voltage -4 to each. By doing this, the drive electric i3
a, 3b, 3C... and control electrodes 5a, 5b, 5C...
A creeping corona discharge is selectively generated in the space region 7 between the ions, and ions generated by the creeping corona discharge are accelerated or absorbed by the electric field between the control electrodes 5a, 5b, 5C... and the screen electrode 10. Then, ion emission is controlled and an electrostatic latent image is formed. In the figure, 1
Reference numeral 9 indicates a conductive layer of the dielectric drum 20.

With the above configuration, in the electrostatic latent image forming apparatus according to this embodiment, the generation of noise due to mutual induction between the drive electrodes is prevented in the following manner. That is, in order to form an electrostatic latent image by the recording head 1, a high frequency high voltage is applied to the drive electrode 3 by the AC power source 15, and at the same time, a control voltage is applied to the drive electrode 3.
An ion control voltage is selectively applied to the m-electrode 5 by an ion control power source 16. Then, the drive electrode 3 to which voltage is applied and the control I! A creeping corona discharge occurs in the ion generation space region 7 at the position where the poles 5 intersect.

At that time, since a high frequency high voltage is applied to the drive electrodes 3a, 3b, 3c..., the adjacent drive electrodes 3a, 3c...
b, 3C... Mutual induction is about to occur via the insulating layer 4. However, the drive electrodes 3a, 3b, 3C...
・A mutual induction prevention electrode 12 is placed on top via an insulating layer 13.
are formed in a --like manner, and the drive electrodes 3a, 3b, 3c.
... and the mutual induction prevention electrode 12 is set larger than the capacitance aC8 between the drive electrodes 3a, 3b, 3c, .... Therefore, the drive electrode 3a,
3b.

When a high frequency high voltage is applied to 3C..., a voltage is induced in the mutual induction prevention electrode 12 due to mutual induction, and a voltage is induced between adjacent drive electrodes 3a, 3b, 3c... due to mutual induction. It's not my turn. Therefore, since only a predetermined voltage is applied to the drive electrodes 3a, 3b, 3..., the mutual induction L9 causes the drive electrodes 3a, 3b, 3...
An extra voltage is applied to C..., and abnormal discharge does not occur, and noise and the like are prevented from occurring.

In addition, when the mutual induction prevention electrode 12 is formed on the insulating substrate 2 to have a thickness of - as in this embodiment, the mutual induction prevention electrode 12 can be easily formed by screen printing or the like. can be formed into In addition, the drive electrode 3a
, 3b, 3C... Since there is no need to interpose a new member between the drive electrodes 3a, 3b, 3C..., the resolution of the drive electrodes 3a, 3b, 3C, etc. is not impaired.

FIG. 5 shows another embodiment of the present invention, in which the same parts as in the previous embodiment are given the same reference numerals as φ, and in this embodiment, the mutual induction prevention electrode is It is not provided over the entire surface as in the case of the conventional method, but is provided only at the position corresponding to the drive electrode. That is, on the insulating substrate 2, mutual induction prevention electrodes 12a112b, 12C...
are provided in the same pattern at positions corresponding to the drive electrodes 3a, 3b, 3C, . . . These mutual induction prevention electrodes 12a, 12b, 12c-... are drive electrodes 3a.

Similar to 3b, 3G, etc., it is formed by pattern printing a metal such as tungsten using a screen printing method or the like.

In such a case, mutual induction prevention electrodes 12a, 112b, 12c, .
By facing each other, the capacitance ω between the electrodes can be reduced compared to when the mutual induction prevention electrodes 12 are provided over the entire surface, and electrostatic loss when AC voltage is applied is reduced. Therefore, a head with low power consumption can be achieved, and the device can be made smaller. In addition, the mutual induction prevention electrode 12
When forming a112b, 12c..., the drive electrode 3
a.

The same screen printing masks as 3b, 3C, etc. can be used.

Other configurations and functions are the same as in the previous embodiment, so
The explanation will be omitted.

FIG. 6 shows still another embodiment of the present invention, in which the same parts as in the previous embodiment are denoted by the same reference numerals. Electrodes are arranged. That is, the mutual induction prevention electrodes 12a, 12b, 12G...
, 3c... are provided narrower in width. These mutual induction prevention electrodes 12a, 12b, 12c-... are placed on the insulating substrate 2 at the same time as the drive electrodes 3a13b, 3C...
It is formed by pattern printing a metal such as tungsten using a screen printing method or the like. The thickness of the mutual induction prevention electrodes 12a, 12b112c, . . . is set in the same manner as the drive electrodes 3a, 3b, 3C, .

The capacitance of the region A, /M between the drive electrode 3 and the mutual induction prevention electrodes 12 on both sides is C9, and the drive A electrodes 3a, 3b, 3c... and the control electrodes 5a, 5b.
, 5C, .
A The distance to the conduction prevention electrode 12 is set.

In such a case, the mutual induction prevention electrodes 12a, 12b
, 12 cm, . . . can be screen printed simultaneously with the drive electrodes 3a13b, 3C, . . . , thereby saving steps and improving productivity.

Other configurations and functions are the same as those in the previous embodiment, so
I will omit the explanation.

[Effects of the Invention] This invention has the above configuration and operation, and can prevent mutual induction from occurring between the first electrodes.
It is possible to provide an electrostatic latent image forming device that does not generate noise due to excessive discharge.

[Brief explanation of the drawing]

Figure 1 is a sectional view taken along line I-I in Figure 3, and Figure 2 is a cross-sectional view taken along line I-I in Figure 3.
[-It cross-sectional view, FIG. 3 is an electrostatic recording S according to the present invention.
! ii. A partially cutaway plan view showing one embodiment of the neck; FIG. 4 is a cross-sectional view of the same device; FIG. 5 is a cross-sectional view showing another embodiment of the present invention; FIG. 7 is a partially cutaway plan view showing a conventional electrostatic latent image forming device, FIG. 8 is a sectional view taken along the line ■-■ in FIG. 7, and FIG. It is a sectional view taken along line IX-■ in the figure. [Explanation of symbols] 1... Recording head 3... Drive electrode 4... Insulating layer 5... Control m+electrode 12... Electrode for preventing mutual induction Patent applicant: Fuji Xerox Co., Ltd. Immediate Patent Attorney Tomohiro Nakamura (3 others) Fig. 4 Fig. Fig. Fig. a b C Fig. Fig. Fig. IO

Claims (4)

[Claims] (1) A plurality of first electrodes, a plurality of second electrodes, and an insulating substrate are provided, and the first electrode and the second electrode are provided in a matrix with the insulating substrate sandwiched therebetween. , said second
In an electrostatic latent image forming apparatus having a spatial region in which a creeping corona discharge is generated by applying an alternating current voltage between the first electrode and the second electrode, the plurality of first electrodes An electrostatic latent image forming device characterized by being provided with mutual induction prevention electrodes for preventing mutual induction between electrodes. (2) The first electrode is provided with a plurality of mutual induction prevention electrodes.
2. The electrostatic latent image forming apparatus according to claim 1, wherein the electrostatic latent image forming apparatus is provided uniformly over the entire surface of the electrode with an insulating layer interposed therebetween. (3) The first electrode is provided with a plurality of mutual induction prevention electrodes.
2. The electrostatic latent image forming device according to claim 1, wherein the electrostatic latent image forming device is provided only at a position corresponding to the first electrode with an insulating layer interposed therebetween. (4) The electrostatic latent image forming apparatus according to claim 1, wherein the mutual induction prevention electrode is provided between adjacent first electrodes.