JP2745600B2 - Electrostatic latent image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrostatic latent image forming apparatus for forming an electrostatic latent image on a dielectric by modulating an ion flow.

[Related Art] Conventionally, a recording head as this type of electrostatic latent image forming apparatus is configured as follows. This is, as shown in FIGS. 17 and 18, the drive electrode 51 on the insulating substrate 50,
51 ... are provided in parallel with each other and these drive electrodes
The control electrodes 53, 53,... Are provided on the drive electrodes 51, 51,.
And the control electrodes 53 form a matrix. The control electrodes 53, 53 are provided with openings 54, 54 at positions intersecting the drive electrodes 51, 51, respectively.
, A screen electrode 56 is provided via an insulating layer 55. In the insulating layer 55 and the screen electrode 56, openings 57, 57, and 58, 58,... Are formed at positions corresponding to the openings 54, 54,.

The recording head selectively applies a high-frequency high voltage between the driving electrodes 51, 51, and the control electrodes 53, 53, as shown in FIG. An ion control voltage and a DC voltage are applied to the screen electrode 56, respectively. By doing so, the driving electrode 51 and the control electrode 53 corresponding to the matrix to which the high-frequency high voltage is applied
Generates a creeping corona discharge between them, and accelerates or absorbs ions generated by the creeping corona discharge by an electric field formed between the control electrodes 53, 53, and the screen electrode 56, thereby controlling ion emission. As a result, an electrostatic latent image is formed.

By the way, this recording head is manufactured as follows. That is, after the drive electrodes 51, 51,... Are printed in a predetermined pattern with conductive ink on an insulating substrate 50 made of an insulating material, an insulating layer is formed on the substrate 50 on which the drive electrodes 51, 51,. 52 is laminated. Next, control electrodes 53, 53... Are printed in a predetermined pattern on the insulating layer 52 with conductive ink, and an insulating layer 55 is further laminated on the insulating layer 52 on which the control electrodes 53, 53. I do. The material formed by stacking in this manner is fired at a high temperature to integrate the substrate 50, the electrodes 51 and 53, and the insulating layers 52 and 55. Finally, a screen electrode 56 previously formed of a thin metal plate or the like is fixed on the insulating layer 55 by a method such as bonding.

[Problems to be Solved by the Invention] However, the above-described conventional technology has the following problems. That is, in the above recording head,
The drive electrodes 51, 51,... Are formed on the insulating substrate 50 by printing using conductive ink, and the drive electrodes 51, 51,.
It is provided elongated along the longitudinal direction of the substrate 50. Therefore, when the drive electrodes 51, 51,... Are printed on the insulating substrate 50 with the conductive ink, a portion of the drive electrodes 51, 51,. There are parts where the concentration of such conductive material is low
When the materials such as the electrodes 50, the electrodes 51, 53, and the insulating layers 52, 55 are fired and integrated, the solvent, which is a component of the conductive ink forming the drive electrodes 51, 51,. In some cases, a break occurs in the conductive material, and the drive electrode 51 is disconnected. If a break occurs in the drive electrode 51, no discharge occurs at the drive electrode 51, and the recording head becomes defective. However, the drive electrodes 51, 51,... Are laminated between the substrate 50 and the insulating layer 52, and only one end for voltage application is exposed on the substrate 50. electrode
51 disconnections cannot be found.

Therefore, in order to discover the disconnection of the drive electrodes 51, 51 ..., after the recording head is manufactured, a voltage is actually applied to the drive electrodes 51, 51 ... and the control electrodes 53, 53 ... By examining whether or not creepage corona discharge has occurred between the drive electrode 51 and the control electrode 53, the drive electrodes 51, 51
It is necessary to determine whether or not a disconnection has occurred in…
There is a problem that it is very troublesome to check whether the drive electrodes 51, 51...

[Means for Solving the Problems] Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to disconnect a drive electrode as a first electrode. It is an object of the present invention to provide an electrostatic latent image forming apparatus capable of easily confirming whether or not the electrostatic latent image is present.

That is, the present invention includes an insulating substrate, a first electrode, a second electrode, and an insulating layer, and the first electrode and the second electrode are connected to each other with the insulating layer interposed therebetween. Provided in a matrix on a conductive substrate, wherein the second electrode has a spatial region that generates a creeping corona discharge by applying a voltage between the first electrode and the second electrode, First
The electrode has a voltage supply end exposed on an insulating substrate and a free end covered with the insulating layer, and the insulating layer is provided near a free end of the first electrode. First from outside
Is configured to include a conductive portion that can be electrically connected to the electrode.

As the conductive portion, for example, an opening formed so that the first electrode is exposed in the insulating layer is used. The inner surface of the opening may be covered with a conductive material as needed.

The conductive portion may be formed of a metal rod implanted in the insulating layer so as to be conductive with the first electrode.

[Operation] In the present invention, the insulating layer is provided near the free end of the first electrode with a conductive portion that can be electrically connected to the first electrode from outside, so that the conductive layer is exposed on the insulating substrate. The continuity between the voltage supply end of the first electrode and the vicinity of the free end of the first electrode via the continuity part is checked by a continuity tester or the like, so that the disconnection of the first electrode can be easily performed. You can check the presence or absence.

[Embodiments] The present invention will be described below based on the illustrated embodiments.

FIG. 16 shows an image recording apparatus to which the electrostatic latent image forming apparatus according to one embodiment of the present invention can be applied. Referring to FIG. 1, reference numeral 1 denotes a recording head, which generates an ion current in accordance with an image signal to form an electrostatic latent image, as described later. At a position opposed to the recording head 1, a dielectric drum 2 as an image carrier is rotatably disposed. After the recording head 1 has written the electrostatic latent image on the dielectric drum 2, the dielectric drum 2
The electrostatic latent image formed on the surface is developed by the developing device 3. The developed image is transferred and fixed on a recording sheet 5 supplied to the surface of the dielectric drum 2 by a sheet feeding unit 4 by a transfer unit 6 for transferring and fixing the developed image by pressure, and then the recording sheet 5 is discharged. The image is stored in the paper tray 7 and the image is recorded. Dielectric drum 2 after development image is transferred
After the developing toner remaining on the surface is removed by the cleaner 8, the residual charge is erased by the eraser 1 to prepare for the next image recording step.

The electrostatic latent image forming apparatus according to the present invention is used, for example, as the recording head 1 described above.

The recording head 1 as the electrostatic latent image forming apparatus has a second
As shown in FIG. 3 and FIG. 3, drive electrodes 10, 10,... As first electrodes are provided on an insulating substrate 9 in parallel with each other, and on these drive electrodes 10, 10,. Are provided as second electrodes so as to intersect with each other with the insulating layer 11 interposed therebetween. The drive electrodes 10, 10, and the control electrodes 12, 12,... Constitute a matrix. The control electrodes 12, 12,... Are formed with openings 13, 13,... For generating ions at positions intersecting with the drive electrodes 10, 10,.

A screen electrode 15 is provided on the control electrodes 12, 12,... Via an insulating layer 14.
15, openings 16 for deriving ions are formed at positions corresponding to the openings 13, 13,... Of the control electrodes 12, 12,. In the figure, reference numeral 17 denotes an opening formed in the insulating layer 14.

Then, the recording head 1 is, as shown in FIG.
A high-frequency high voltage is selectively applied between the drive electrodes 10, 10,... And the control electrodes 12, 12,.
A power supply 19 applies a pulsed ion control voltage to the control electrodes 12, 12,..., And a DC voltage from the power supply 20 to the screen electrode 15. By doing so, a creeping corona discharge is generated between the driving electrode 10 and the control electrode 12 corresponding to the matrix to which the high-frequency high voltage is applied, at the openings 13, 13,... By accelerating or absorbing the ion flow generated by the electric field formed between the control electrodes 12, 12... And the screen electrode 15, by controlling the discharge of the ion flow, An electrostatic latent image is formed according to an image signal. In the figure, reference numeral 21 denotes a conductive layer of the dielectric drum 2.

The recording head is manufactured as follows. That is, the insulating substrate 9 and the insulating layers 11 and 14 are formed by ceramics such as alumina and zirconia. The insulating substrate 9 is formed in a relatively thick plate shape before firing the ceramic material, and a conductive material made of tungsten, silver, or the like is dispersed in a solvent on the surface of the insulating substrate 9 in a paste form. The drive electrodes 10, 10,... Are printed in a predetermined shape by the conductive ink. Next, an insulating layer 11 formed in a thin layer before firing the ceramic material is laminated on the insulating substrate 9 on which the driving electrodes 10, 10... Are printed, and the driving electrode is formed on the insulating layer 11. With conductive ink like 10
Are printed in a predetermined shape.

Further, the insulating layer 11 on which the control electrodes 12, 12,.
After laminating a ceramic material in the form of a thin layer forming the insulating layer 14, these materials are fired at a high temperature to be integrated.

Finally, a screen electrode 15 formed in advance by a thin metal plate on the insulating layer 14 is fixed to the screen electrode 15 by means such as adhesion or sticking.

At this time, the drive electrodes 10, 10,... Are provided to be elongated along the longitudinal direction of the insulating substrate 9, so that when the drive electrodes 10, 10,. Due to the non-uniformity of the concentration or the like, a portion where the concentration of the conductive material of the conductive ink is low may partially occur in the drive electrode 10. As described above, when a portion where the concentration of the conductive material of the conductive ink is low occurs in the drive electrode 10 partially, the solvent which is a component of the conductive ink is vaporized when the recording head is fired, and As shown in the drawing, a crack may occur in the conductive material and the drive electrode 10 may be disconnected. The disconnection of the drive electrode 10 also occurs due to thermal distortion or the like during firing. Such disconnection of the drive electrode 10 also occurs when the recording head is manufactured by another method as described later, since the drive electrode 10 is formed to be elongated.

However, the recording head is not limited to this, and the insulating substrate 9 and the insulating layers 11 and 14 may be formed of a synthetic resin such as bakelite or glass epoxy, or an inorganic material such as glass or mica. Of course it is good. In this case, the drive electrodes 10, 10,... And the control electrodes 12, 12,... May be formed by forming a thin metal plate such as stainless steel or nickel into a predetermined shape by etching or the like.

By the way, in this embodiment, the drive electrode has a voltage supply end exposed on the insulating substrate and a free end covered with an insulating layer, and the insulating layer is free of the drive electrode. It is configured to have a conductive portion near the end portion that can be electrically connected to the drive electrode from the outside.

That is, as shown in FIG. 5, the drive electrodes 10, 10,... Are provided with discharge electrodes 10a, 10a... Formed linearly along the longitudinal direction on the surface of the insulating substrate 9. The discharge electrode portions 10a are arranged in parallel with each other at a predetermined interval. Also, the discharge parts 10a, 1 of each drive electrode
0a... Are drawn in substantially L-shape to the opposite side every other end, and a voltage formed widely at the edge of the insulating substrate 9 in the width direction is provided at the drawn end. Feed ends 10b, 10b ...
Is provided. In addition, the voltage supply end of the drive electrode
.. Are drawn to the opposite edge of the substrate 9 with respect to the center of the insulating substrate 9 in the width direction.

Also, as shown in FIG. 1, the voltage supply ends 10b, 10b... Of the drive electrodes are exposed on the surface of the substrate 9 even when the drive electrodes 10, 10. Has become.

On the other hand, the free ends 10c of the drive electrodes are located between the discharge electrode portions 10a, and are covered with the insulating layer 11. The discharge electrode portions 10a of the drive electrodes, 10a ...
Are arranged at predetermined intervals according to the recording density of the recording head.

Further, as shown in FIGS. 6 and 7, a conducting terminal 23 is integrally provided at the free ends 10c, 10c... Of the driving electrode. It is formed in a circular shape having a diameter larger than the line width. Since the line width of the drive electrode 10 is set to, for example, about 40 to 150 μm, the diameter of the terminal 23 is set to about several mm. If the distance between the discharge electrode portions 10a of the drive electrodes is too small to form the terminal 23 between the discharge electrode portions 10a, 10a, as shown in FIG. May be provided on the voltage supply ends 10b of the drive electrodes.

In addition, the insulating layers 11 and 14 covering the drive electrodes 10, 10,... Have openings having the same shape as the shape of the terminals 23 at positions corresponding to the terminals 23, 23,. Part 24, 24 ...
Are drilled. After the recording head is manufactured, holes may be formed in the insulating layers 11 and 14 by a laser processing machine or the like. When laminating, the openings 24, 24 ...
May be provided. And this opening
Via the terminals 23, 23 of the drive electrodes 10, 10 via the 24, 24,
Test terminals such as a continuity tester can be conducted.

In the above configuration, in this embodiment, the disconnection of the drive electrode of the recording head manufactured as follows is inspected. That is, when the recording head is manufactured, the insulating substrate 9, the drive electrodes 10, 10,... And the insulating layers 11, 14 are baked to form them uniformly, and before the screen electrode 15 is fixed on the insulating layer 14. Next, an inspection for checking the disconnection of the drive electrodes 10, 10,... Is performed. Therefore, as shown in FIG. 9, one test rod 26 of a continuity tester 25 capable of measuring a resistance value is connected to the voltage supply end 10b of the drive electrode to be inspected exposed on the insulating substrate 9 of the recording head. And a terminal 23 provided at the free end 10c of the same drive electrode, as shown in FIG. 10, through an opening 24 formed in the insulating layer 11 and the insulating layer 14, and The one test rod 27 of 25 is brought into contact.

Then, the drive electrode 10 to be inspected by the continuity tester 25
The resistance value of the driving electrode 10 is measured to check whether the driving electrode 10 is disconnected or the resistance value of the driving electrode 10 is not abnormally high. The resistance value of the drive electrode 10 is determined by the conductivity of the material forming the drive electrode 10 and the length and cross-sectional area of the electrode. The resistance value of the drive electrode 10 may be, for example, several Ω or less.

Thus, the insulating layers 11 and 14 covering the drive electrodes 10 include:
The free end 10c of the drive electrode is provided with an opening 24 that can be electrically connected to the drive electrode 10 from the outside, so that the voltage supply end 10b of the drive electrode exposed on the insulating substrate 9 and the opening The continuity between the drive electrode 10 and the terminal 23 provided at the free end 10c of the drive electrode via 24 is checked by the continuity tester 25, so that the presence or absence of disconnection of the drive electrode 10 can be easily confirmed.

In the above embodiment, the case where the disconnection of the drive electrode 10 is checked by the continuity tester 25 has been described.However, the present invention is not limited to this, and a high-frequency high voltage is applied to the drive electrode 10. The disconnection of the drive electrode 10 may be inspected using an LCZ meter or the like capable of measuring the reactance (L), capacitance (C), and impedance (Z) of the electrode. In this case, it is possible to measure not only the resistance value of the driving electrode 10 but also the reactance (L), the capacitance (C), and the impedance (Z) corresponding to the frequency of the high-frequency high voltage applied to the driving electrode 10. Thus, the quality of the drive electrode 10 can be checked in accordance with actual use conditions. Further, a commercially available tester or the like may be used instead of the continuity tester.

FIG. 11 shows another embodiment of the present invention, in which the same parts as those in the above embodiment are denoted by the same reference numerals and described. In this embodiment, among the openings provided in the insulating layer, By covering the peripheral surface with a conductive material, it is possible to electrically conduct from the surface of the insulating layer to the vicinity of the free end of the drive electrode. That is, as shown in FIG. 12, terminals 23 having a smaller diameter than the terminals 23 are provided at the free ends 10c, 10c... Of the drive electrodes, so that the openings provided in the insulating layers 11, 14 are provided. The diameter of the portion 24 is also set smaller than that of the embodiment. A terminal lead-out portion 30 is provided on the inner peripheral surface of the opening 24 by means such as printing or plating of a conductive material. Further, on the surface of the insulating layer 14, a flange 31 is provided integrally with the terminal lead-out portion 30.

In such a case, when checking the continuity of the drive electrode 10, as shown in FIG. 13, the test rod 26 of the continuity tester 25 only needs to be brought into contact with the flange 31 of the terminal lead-out portion 30, so that
The conduction of the drive electrode 10 can be easily inspected. In addition, since the diameter of the opening 24 provided in the insulating layers 11 and 14 can be reduced, the opening 24 is provided near the free end 10c of the driving electrode even when the distance between the driving electrodes 10, 10 is narrow. Can be.

In this embodiment, the case where the flange 31 is provided in the terminal lead-out portion 30 has been described, but as shown in FIG.
The terminal lead-out section 30 does not need to be provided with the flange 31.

Other configurations and operations are the same as those of the above-described embodiment, and a description thereof will be omitted.

FIG. 15 shows still another embodiment of the present invention. The same portions as those of the above embodiment are denoted by the same reference numerals and described. In this embodiment, an opening is formed in an insulating layer. Instead, by implanting a metal rod in the insulating layer, the drive electrode can be electrically connected to the drive electrode from outside in the vicinity of the free end of the drive electrode. That is, the insulating layers 11 and 14
As shown in FIG. 15, a thin metal rod 40 is implanted on the free end 10 of the drive electrode 10.
Conducted to c. The metal rod 40 is provided by implanting the metal rod 40 at a predetermined position before firing the insulating substrate 9 and the insulating layers 11 and 14.

In such a case, the conductive portion can be formed even when the distance between the drive electrodes 10, 10,... Is considerably small.

Other configurations and operations are the same as those of the above-described embodiment, and the description thereof will be omitted.

[Effects of the Invention] The present invention has the above configuration and operation, and can provide an electrostatic latent image forming apparatus capable of easily confirming whether or not the first electrode is disconnected.

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part showing an embodiment of an electrostatic latent image forming apparatus according to the present invention, FIG. 2 is a sectional view of an essential part showing a recording head, FIG. 4 is an explanatory view showing a disconnection of the drive electrode, FIG. 5 is a perspective view showing the drive electrode, FIG. 6 is a cross-sectional view showing the conduction portion, FIG. 7 is a plan view of the same, FIG. FIG. 9 is an explanatory view showing the operation of this embodiment, FIG. 10 is a sectional view showing the same, FIG. 11 is a sectional view showing another embodiment of the present invention, and FIG. Plan view, No.
13 is a cross-sectional view showing the operation of the same example, FIG. 14 is a cross-sectional view showing a modification of the same example, FIG. 15 is a cross-sectional view showing still another embodiment of the present invention, and FIG. Configuration diagram showing an image recording apparatus to which the electrostatic latent image forming apparatus can be applied, FIG. 17 and FIG.
FIG. 18 is a cross-sectional view showing a conventional recording head and a plan view with a part removed. [Explanation of Symbols] 1 ... Recording head 9 ... Insulating substrate 10 ... Driving electrode 10a ... Discharge electrode portion 10b ... Voltage supply end portion 10c ... Free end portion 11, 14 ... Insulating layer 12 … Control electrode 13… Opening 23… Terminal 24… Opening 25… Continuity tester 26… Test rod

Claims (4)

(57) [Claims] An insulating substrate, a first electrode, a second electrode, and an insulating layer, wherein the first electrode and the second electrode sandwich the insulating layer with the insulating layer interposed therebetween. The second electrode is provided in a matrix on a substrate, and the second electrode has a spatial region that generates a creeping corona discharge by applying a voltage between the first electrode and the second electrode; The first electrode includes a voltage supply end exposed on an insulating substrate and a free end covered with the insulating layer, and the insulating layer is provided near a free end of the first electrode. An electrostatic latent image forming apparatus, further comprising a conductive portion that can be electrically connected to the first electrode from outside. 2. The electrostatic latent image forming apparatus according to claim 1, wherein said conductive portion comprises an opening formed so that said first electrode is exposed in said insulating layer. 3. An electrostatic latent image forming apparatus according to claim 2, wherein an inner surface of said opening is covered with a conductive material. 4. The electrostatic latent image forming apparatus according to claim 1, wherein said conductive portion is formed of a metal rod implanted in said insulating layer so as to be conductive with said first electrode.