JP2012159777A - Charging device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging device employing an MHCD method for an image forming apparatus, where feeder cables do not interfere with members such as materials to be charged.SOLUTION: A charging device 300 includes: a belt-like first electrode 301; a belt-like second electrode 304 that faces the first electrode 301; a first intermediate layer 302 that is provided on a surface of the first electrode 301 facing the second electrode 304, and has resistance higher than that of the first electrode 301; a second intermediate layer 303 that is provided between the first intermediate layer 302 and the second electrode 304, and inhibits conduction; a hole 305 that penetrates the second electrode 304 and the second intermediate layer 303; and a feeder cable connection part 314 that is integrally provided at one end in the longitudinal direction of the second electrode 304, and has width in a direction intersecting with the longitudinal direction wider than that of the second electrode 304.

Description

  The present invention relates to a charging device and an image forming apparatus.

An electrophotographic image forming apparatus includes a charging device. The charging device is used for charging the photosensitive drum, charging the toner for developing the latent image on the photosensitive drum, charging the transfer belt when transferring the toner image on the photosensitive drum to the transfer belt, and the like.
In recent years, research on a charging device of an MHCD (Micro Hollow Cathode Discharge) type has been advanced. FIG. 3 is a diagram of the MHCD charging device 200 as viewed from the charged object side. FIG. 4 is a cross-sectional view taken along the line II of FIG. 3, and also shows the positional relationship with the photosensitive drum 11 which is an example of an object to be charged. The charging device 200 is configured by laminating a first electrode 201, a first intermediate layer 202 having a higher resistivity than the first electrode 201, a second intermediate layer 203 that blocks conduction, and a second electrode 204. A number of holes 205 penetrating the second electrode 204 and the second intermediate layer 203 are provided. The power source 206 applies a voltage to the first electrode 201 and the second electrode 204 via the feeder lines 207 and 208, respectively, but applies a higher voltage to the first electrode 201 than the second electrode 204. Then, a discharge occurs due to a potential difference between the first intermediate layer 202 and the second electrode 204, and charged particles are emitted. The charged particles are transferred to the surface of the object to be charged by the drift electric field generated between the second electrode 204 and the object to be charged, and as a result, the object to be charged is charged.
As an invention related to an MHCD charging device, Patent Document 1 proposes a structure in which an intermediate layer is projected to the contact side in order to prevent discharge from the contact point between the feeder line and the first electrode to the second electrode. Has been.

JP 2000-267390 A

Incidentally, in the charging device 200 described above, since the power supply line 208 to the second electrode 204 is provided at a position close to the object to be charged, interference between the power supply line 208 and a member such as the object to be charged becomes a problem. For example, since the distance between the photoconductive drum 11 and the second electrode 204 is only about several hundred to several thousand μm, there is a possibility that discharge occurs between the power supply line 208 and the surface of the photoconductive drum 11. Further, both ends of the photosensitive drum 11 are supported by bearings 111, and a gear 112 for transmitting power is provided at one end. In the case of such a structure, the feeder line 208 may interfere with the bearing 111 and the gear 112. The same problem can occur when toner or transfer belt is used as an object to be charged.
An object of the present invention is to prevent a power supply line from interfering with a member such as an object to be charged when an MHCD charging device is used in an image forming apparatus.

  The charging device according to claim 1 is provided on a surface of the first electrode having a band shape, a second electrode having a band shape facing the first electrode, and a surface of the first electrode facing the second electrode. A first intermediate layer having a resistivity higher than that of one electrode; a second intermediate layer provided between the first intermediate layer and the second electrode for preventing conduction; the second electrode and the second electrode; A hole penetrating the intermediate layer, and a feeder line connecting portion integrally provided at one end portion in the longitudinal direction of the second electrode and having a wider width in the direction intersecting the longitudinal direction than the second electrode It is characterized by having.

  The charging device according to claim 2 is provided on a surface of the first electrode having a band shape, a second electrode having a band shape facing the first electrode, and a surface of the first electrode facing the second electrode. A first intermediate layer having a resistivity higher than that of one electrode; a second intermediate layer provided between the first intermediate layer and the second electrode for preventing conduction; the second electrode and the second electrode; A hole penetrating the intermediate layer, and a feed line connecting portion integrally provided at one end portion in the longitudinal direction of the second electrode and having a shape extending from the end portion toward the first electrode side It is characterized by having.

  The charging device according to claim 3 is provided on a surface of the first electrode having a strip shape, a second electrode having a strip shape facing the first electrode, and a surface of the first electrode facing the second electrode. A first intermediate layer having a resistivity higher than that of one electrode; a second intermediate layer provided between the first intermediate layer and the second electrode for preventing conduction; the second electrode and the second electrode; A hole penetrating through the intermediate layer, and at least one end in the longitudinal direction of the laminate composed of the first electrode, the first intermediate layer, the second intermediate layer, and the second electrode. And a coating layer for preventing conduction.

  The charging device according to claim 4 is the charging device according to any one of claims 1 to 3, wherein a distance between the first intermediate layer and the second electrode inside the hole is the outside of the hole. The distance between the first intermediate layer and the second electrode is shorter.

  An image forming apparatus according to a fifth aspect is based on the charging device according to any one of the first to fourth aspects, a photosensitive member that is charged by the charging device and changes in potential by light irradiation, and image data. An exposure device that irradiates light to the photosensitive member, a developing device that develops a latent image on the photosensitive member, and a transfer device that transfers an image developed on the photosensitive member to a recording medium. To do.

According to the first, second, third, and fifth aspects of the present invention, when the MHCD charging device is used in the image forming apparatus, the power supply line can be prevented from interfering with a member such as an object to be charged.
According to the invention which concerns on Claim 4, it can be made difficult to generate | occur | produce an unnecessary discharge and electric leakage.

2 is a diagram illustrating a hardware configuration of the image forming apparatus 100. FIG. 1 is a diagram illustrating a configuration of an image forming engine 10. It is the figure which looked at the charging device 200 from the to-be-charged object side. It is sectional drawing in the II line | wire of FIG. FIG. 3 is a view of the charging device 300 as viewed from the photosensitive drum 11 side. It is sectional drawing in the II-II line of FIG. It is sectional drawing in the III-III line of FIG. It is the figure which expanded the left end part of the charging device 300 in FIG. FIG. 3 is a view of the charging device 400 as viewed from the photosensitive drum 11 side. It is sectional drawing in the IV-IV line of FIG. FIG. 2 is a view of the charging device 500 as viewed from the photosensitive drum 11 side. It is sectional drawing in the VV line of FIG. In this example, the diameter of the hole 305 in the second electrode 304 is larger than the diameter in the second intermediate layer 303. In this example, the second intermediate layer 303 is formed so as to protrude outside the charging device 300. This is an example in which the second region is formed to warp in a direction away from the photosensitive drum 11. In this example, the second electrode 404 is formed by rounding the corners facing the photosensitive drum 11 in the second region.

(1) First Embodiment FIG. 1 is a diagram illustrating a hardware configuration of an image forming apparatus 100.
The control unit 4 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory) (all not shown). The storage unit 5 is, for example, a hard disk storage device, and stores an OS (Operating System), application programs, and the like. The ROM stores a program representing the OS reading and starting procedures. The RAM is used as a work area when the CPU executes various programs.

The instruction receiving unit 1 has a display unit and a keyboard. The display unit is, for example, a liquid crystal display device, and displays an image representing an operator corresponding to the operation content. The display unit includes a sensor for recognizing an area touched by the user on the screen, and an operator touched by the user is specified by the sensor. The keyboard has start, stop, reset keys and numeric keys. The instruction received by the instruction receiving unit 1 is sent to the control unit 4, and the control unit 4 controls the image forming apparatus 100 according to this instruction.
A communication I / F (Interface) 6 is connected to communication means (not shown) such as a LAN (Local Area Network), and the image forming apparatus according to a communication protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol). Mediates communication between 100 and other devices.

The image input unit 2 optically reads a document and generates image data. Specifically, the image input unit 2 includes a platen glass, a light source, a reflecting mirror, an image sensor, and an A / D conversion unit (all not shown). The light source irradiates the document placed on the platen glass with light, and the reflected light enters the image sensor via the reflecting mirror. The imaging device converts the reflected light into an image signal representing R (Red) color, G (Green) color, and B (Blue) color. This image signal is supplied to the image processing unit 3.
The image processing unit 3 performs A / D conversion on the image signal supplied from the image input unit 2 and performs image processing such as color conversion, enlargement / reduction, background removal, and binarization. In color conversion processing, an image composed of R, G, and B colors is decomposed into Y (Yellow), M (Magenta), C (Cyan), and K (Black) images, and an image for each pixel. Image data representing the area ratio is generated. The image data subjected to the image processing is read at a predetermined timing and supplied to the image output unit 7.

The main components of the image output unit 7 are an image forming engine 10Y, 10M, 10C, 10K, a transfer belt 20, a medium supply unit 30, and a fixing device 40.
The image forming engines 10Y, 10M, 10C, and 10K are respectively based on the image data supplied from the image processing unit 3 by an electrophotographic method, using Y (Yellow) color, M (Magenta) color, C (Cyan) color, A K (Black) toner image is formed on the surface of the transfer belt 20 in an overlapping manner. Since the image forming engines have the same configuration, the image forming engines are collectively referred to as the image forming engines when it is not necessary to distinguish the image forming engines. In that case, Y, M, C, and K are also omitted for the components of the image forming engine 10.

FIG. 2 is a diagram illustrating a configuration of the image forming engine 10. The image forming engine 10 is configured by providing a charging device 300, an exposure device 13, a developing device 14, a transfer device 15, and the like around the photosensitive drum 11.
The photosensitive drum 11 is a cylindrical rotating body that is driven to rotate in the direction of arrow A.
The charging device 300 charges the surface of the photosensitive drum 11 to a predetermined potential.

  The exposure device 13 is a scanning optical system that irradiates the surface of the photosensitive drum 11 with an exposure beam LB. Specifically, the exposure apparatus 13 includes a semiconductor laser and a rotating polygon mirror (both not shown). The exposure device 13 receives supply of image data from the image processing unit 3, and generates an exposure beam LB based on the image data by a semiconductor laser. The rotary polygon mirror is driven to rotate at a predetermined angular velocity. The exposure device 13 deflects and scans the surface of the photosensitive drum 11 at a predetermined speed in the main scanning direction by reflecting the generated exposure beam LB with a rotary polygon mirror, and each pixel represented by image data. A latent image corresponding to the image area ratio is written in the main scanning direction. On the surface of the photosensitive drum 11, the potential of the portion where the latent image is written is lowered to a predetermined level. Here, the main scanning direction is a direction that coincides with the direction of the rotation axis of the photosensitive drum 11, and the arrangement of pixels in the main scanning direction is referred to as a scanning line. The sub-scanning direction is a direction orthogonal to the main scanning direction, that is, the circumferential direction of the photosensitive drum 11, and writing of the latent image in units of scanning lines is repeated in the sub-scanning direction when the photosensitive drum 11 is driven to rotate.

The developing device 14 develops the latent image formed on the surface of the photosensitive drum 11. Specifically, the developing device 14 contains a developer composed of toner and carrier, and the developer is charged to a predetermined potential. Then, the toner is transferred to the surface of the photosensitive drum 11 by the potential difference between the latent image on the photosensitive drum 11 and the developer, and a toner image is formed.
The transfer belt 20 is wound around the drive roller 21 and the roller 22 with a constant tension, and the transfer belt 20 is driven to circulate in the direction of the arrow B when the drive roller 21 is driven to rotate. A transfer device 15 is provided at a position facing the photoconductive drum 11 across the transfer belt 20, and the transfer device 15 charges the transfer belt 20 with a polarity opposite to that of the photoconductive drum 11. Then, the toner is transferred to the transfer belt 20 by electrostatic attraction. This transfer operation is called primary transfer.
The toner removing device 16 has a plate-like member, and removes toner remaining on the surface of the photosensitive drum 11 by pressing the tip of the member against the surface of the photosensitive drum 11.
The above is the configuration of the image forming engine 10. The toner images formed by the image forming engines 10Y, 10M, 10C, and 10K are transferred onto the transfer belt 20 in an overlapping manner.

  In the medium supply unit 30, recording media P are stacked and accommodated. The recording medium P is, for example, paper having a size defined by JIS (Japanese Industrial Standard). The feeding roller 31 is pressed against the upper surface of the stacked recording media P, and when a toner image is formed on the surface of the transfer belt 20, the control unit 4 drives the feeding roller 31 to rotate, thereby recording the recording medium. P is sent out to the conveyance path 32 one by one. The sent recording medium P is transported in the direction of arrow C along the transport path 32 by a roller pair 33 that is rotationally driven.

The transfer roller 23 charges the recording medium P with a polarity opposite to that of the transfer belt 20. In synchronization with the toner image formed on the surface of the transfer belt 20 reaching the position of the transfer roller 23, the transfer roller 23 is pressed against the transfer belt 20 with a predetermined load. When the recording medium P enters the contact area, the toner image on the transfer belt 20 is transferred to the surface of the recording medium P by the action of electrostatic attraction and pressure. This transfer operation is called secondary transfer.
The recording medium P on which the toner image is transferred is guided to the fixing device 40. The fixing device 40 fixes the toner image on the surface of the recording medium P by heating and pressing the toner image.

Next, the charging device 300 will be described. 5 is a view of the charging device 300 as viewed from the photosensitive drum 11, FIG. 6 is a cross-sectional view taken along the line II-II in FIG. 5, and FIG. 7 is taken along the line III-III in FIG. It is sectional drawing. 6 and 7 also show the positional relationship with the photosensitive drum 11 that is the object to be charged. Note that the dimensional ratios in the figure are different from actual ones for convenience of illustration.
The charging device 300 includes a strip-shaped first electrode 301 and a strip-shaped second electrode 304 facing the first electrode 301. At one end in the longitudinal direction of the second electrode 304, a feeder line connection portion 314 having a width in the direction intersecting the longitudinal direction wider than that of the second electrode 304 is provided integrally with the second electrode 304. Similarly, the first electrode 301 is integrally provided with a feed line connecting portion 311 that faces the feed line connecting portion 314.

A first intermediate layer 302 is provided on the surface of the first electrode 301 facing the second electrode 304 and the surface of the power supply line connecting portion 311 facing the power supply line connecting portion 314, and the first intermediate layer 302 is provided. The second intermediate layer 303 is provided between the second electrode 304 and the feeder connection portion 314. Further, a large number of holes 305 are provided through the second electrode 304 and the second intermediate layer 303.
The power source 306 is connected to the power supply line connection unit 311 by the power supply line 307 and is connected to the power supply line connection unit 314 by the power supply line 308. As shown in FIGS. 5 and 7, the power supply line 308 is connected to a position farthest from the photosensitive drum 11, the bearing 111, and the gear 112 on the power supply line connection portion 314.

The first electrode 301, the first intermediate layer 302, the second intermediate layer 303, and the second electrode 304 are formed by sequentially laminating ink, for example, by screen printing. For the first electrode 301, the second electrode 304, the feed line connecting portion 311, and the feed line connecting portion 314, for example, silver-based or graphite-based ink is used. The first intermediate layer 302 has a volume resistivity of 10 ⁵ Ω · cm to 10 ¹⁰ Ω · made of a material having a higher volume resistivity than the first electrode 301 and the second electrode 304, for example, silicon rubber in which graphite is dispersed. Use ink of about cm. For the second intermediate layer 303, a material that blocks electrical conduction between the first intermediate layer 302 and the second electrode 304, for example, an ultraviolet curable resist ink is used. The thickness of each layer is 100 μm for the first electrode 301, 150 μm for the first intermediate layer 302, 100 μm for the second intermediate layer 303, and 18 to 36 μm for the second electrode 304. When the above layers are formed, a large number of holes 305 having a radius of about 50 to 100 μm that penetrate the second electrode 304 and the second intermediate layer 303 are provided by etching or laser processing. That is, in FIG. 6, the second intermediate layer 303 and the second electrode 304 are exposed on the side surface of the hole 305, and the first intermediate layer 302 is exposed on the ceiling of the hole 305.
Note that the thickness of each layer and the size of the hole 305 are examples.

The distance between the second electrode and the surface of the photosensitive drum 11 is set to about 200 to 2000 μm. The power source 306 applies a higher voltage to the first electrode 301 than the second electrode 304. For example, −2000 V is applied to the first electrode 301 and −800 V is applied to the second electrode 304. On the other hand, the photosensitive drum 11 is grounded. Then, a discharge occurs due to a potential difference between the first intermediate layer 302 and the second electrode 304, and charged particles are emitted. The charged particles are transferred to the surface of the photosensitive drum 11 by the drift electric field generated between the second electrode 304 and the surface of the photosensitive drum 11, and as a result, the surface of the photosensitive drum 11 is charged.
As shown in FIGS. 5 to 7, the second electrode 304 is formed so that the area viewed from the photosensitive drum 11 side is smaller than that of the second intermediate layer 303. FIG. 8 is an enlarged view of the left end portion of the charging device 300 in FIG. As described above, since the second electrode 304 is formed by retreating the edge part by the length z from the second intermediate layer 303, the first intermediate layer 302 and the second electrode 304 in the hole 305 are formed. The distance a is smaller than the distance y + z between the first intermediate layer 302 and the second electrode 304 outside the hole 305. Accordingly, since the electric field generated between the first intermediate layer 302 and the second electrode 304 is larger inside the hole 305 than outside, it is difficult for electric discharge and leakage outside the hole 305 to occur.

(2) Second Embodiment The image forming apparatus 100 of the second embodiment is provided with a charging device 400 shown in FIGS. 9 and 10 instead of the charging device 300 of the first embodiment. 9 is a view of the charging device 400 as viewed from the photosensitive drum 11, and FIG. 10 is a cross-sectional view taken along line IV-IV in FIG.
The charging device 400 includes a strip-shaped first electrode 401 and a strip-shaped second electrode 404 facing the first electrode 401. A first intermediate layer 402 is provided on a surface of the first electrode 401 facing the second electrode 404, and a second intermediate layer 403 is provided between the first intermediate layer 402 and the second electrode 404. Yes. Further, a large number of holes 405 that penetrate the second electrode 404 and the second intermediate layer 403 are provided.

At one end portion in the longitudinal direction of the second electrode 404, a feeder line connection portion 414 having a shape extending from the end portion toward the first electrode 401 side is provided integrally with the second electrode 404. Further, the end of the second intermediate layer 403 is formed so as to cover the end of the first intermediate layer 402 in order to prevent discharge between the first intermediate layer 402 and the feeder connection portion 414. The power source 406 is connected to the first electrode 401 by a power supply line 407 and is connected to the power supply line connection unit 414 by a power supply line 408. As shown in FIG. 10, the power supply line 408 is connected to a position farthest from the photosensitive drum 11, the bearing 111, and the gear 112 in the power supply line connection portion 414.
The material and manufacturing method of each layer of the charging device 400 are the same as those in the first embodiment.

(3) Third Embodiment The image forming apparatus 100 of the third embodiment is provided with a charging device 500 shown in FIGS. 11 and 12 instead of the charging device 300 of the first embodiment. FIG. 11 is a view of the charging device 500 viewed from the photosensitive drum 11 side, and FIG. 12 is a cross-sectional view taken along the line VV of FIG.
The charging device 500 includes a strip-shaped first electrode 501 and a strip-shaped second electrode 504 facing the first electrode 501. A first intermediate layer 502 is provided on a surface of the first electrode 501 facing the second electrode 504, and a second intermediate layer 503 is provided between the first intermediate layer 502 and the second electrode 504. Yes. Further, a large number of holes 505 that penetrate the second electrode 504 and the second intermediate layer 503 are provided. Further, the laminated body composed of the first electrode 501, the first intermediate layer 502, the second intermediate layer 503, and the second electrode has all the surfaces except the surface facing the photosensitive drum 11 as the second intermediate layer 503. It is covered by a covering layer 510 made of the same material.

The power source 506 is connected to the first electrode 501 by a power supply line 507 and is connected to the second electrode 504 by a power supply line 508. As shown in FIG. 12, the power supply line 508 penetrates the coating layer 510 from one end in the longitudinal direction of the charging device 500 and is connected to the second electrode 504. In order to keep the power supply line 508 away from the photosensitive drum 11, the bearing 111, and the gear 112, the power supply line 508 may be wired along the coating layer 510. Since the covering layer 510 is made of a material that prevents conduction, even if the feeder line 508 is wired on the surface of the covering layer 510, the feeder line 508, the first electrode 501, the first intermediate layer 502, the second electrode There is no possibility that a short circuit or a discharge will occur with 504.
The material and manufacturing method of each layer of the charging device 500 are the same as those in the first embodiment.

(4) Modifications Modifications shown below may be combined with each other.
(4.1) Modification 1
The charging device 300 shown in FIG. 8 may be modified as follows.
FIG. 13 shows an example in which the diameter of the hole 305 in the second electrode 304 is formed to be larger than the diameter in the second intermediate layer 303. In this case, the distance a + b between the first intermediate layer 302 and the second electrode 304 inside the hole 305 is formed to be smaller than the distance y + z between the first intermediate layer 302 and the second electrode 304 outside the hole 305. To do.
FIG. 14 shows an example in which the second intermediate layer 303 is formed so as to protrude outside the charging device 300. In this case, the distance a + b between the first intermediate layer 302 and the second electrode 304 inside the hole 305 is formed to be smaller than the distance x + y + z between the first intermediate layer 302 and the second electrode 304 outside the hole 305. To do.
Note that the charging device 400 may be similarly modified.

(4.2) Modification 2
The charging device 300 may be modified as follows. FIG. 15 is a cross-sectional view taken along the line III-III in FIG. 6, and is an example in which the power supply line connecting portion 314 is formed to warp in a direction away from the photosensitive drum 11.
In addition, the charging device 300 may not be provided with the feeder connection portion 311. In this case, the feeder line 307 is directly connected to the first electrode 301. In this case, the portion corresponding to the feeder connection portion 311 in the first intermediate layer 302 may not be provided.
The charging device 400 may be modified as follows. FIG. 16 shows an example in which the corner portion of the power supply line connecting portion 414 facing the photosensitive drum 11 is rounded. The reason for this is that when the corner is sharp, an electric field may concentrate on the corner and unnecessary discharge may occur. It is desirable to round all corners of the first electrode 401, the second electrode 404, and the feeder connection portion 414 in addition to the illustrated portion. Further, the charging device 300 may be similarly modified.
The coating layer 510 of the charging device 500 includes at least one end in the longitudinal direction of the laminate including the first electrode 501, the first intermediate layer 502, the second intermediate layer 503, and the second electrode 504, that is, the power supply line 507. And 508 may be provided at the end on the side where the 508 is provided.

(4.3) Modification 3
The charging device shown in the embodiment may be applied in addition to charging the photosensitive drum 11. For example,
You may apply as a means to charge the toner adhering to the image development roll provided in the image development apparatus 14. FIG. Further, it may be applied as means for charging the transfer belt 20 in the transfer device 15.

DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus, 1 ... Instruction reception part, 2 ... Image input part, 3 ... Image processing part, 4 ... Control part, 5 ... Memory | storage part, 6 ... Communication I / F, 7 ... Image output part, 10Y, 10M DESCRIPTION OF SYMBOLS 10C, 10K, 10 ... Image formation engine, 11 ... Photoconductor drum, 12 ... Charging device, 13 ... Exposure device, 14 ... Developing device, 15 ... Transfer device, 16 ... Toner removal device, 20 ... Transfer belt, 30 ... Medium supply section 31... Sending roller 32. Conveying path 33. Roller pair 34. Guide member 35. Guide member 36. DESCRIPTION OF SYMBOLS ... Charging device, 301 ... 1st electrode, 302 ... 1st intermediate | middle layer, 303 ... 2nd intermediate | middle layer, 304 ... 2nd electrode, 305 ... Hole, 306 ... Power supply, 307 ... Feed line, 308 ... Feed line, 311 ... Feed line connection part, 314 ... Feed line connection , 400 ... charging device, 401 ... first electrode, 402 ... first intermediate layer, 403 ... second intermediate layer, 404 ... second electrode, 405 ... hole, 406 ... power supply, 407 ... feed line, 408 ... feed line, 411... Feed line connection section, 500... Charging device, 501... First electrode, 502... First intermediate layer, 503 ... Second intermediate layer, 504 ... Second electrode, 505 ... Hole, 506 ... Power source, 507. 508: Feed line 510: Coating layer

Claims (5)

A strip-shaped first electrode;
A strip-shaped second electrode facing the first electrode;
A first intermediate layer having a higher resistivity than the first electrode, provided on a surface of the first electrode facing the second electrode;
A second intermediate layer provided between the first intermediate layer and the second electrode for preventing conduction;
A hole penetrating the second electrode and the second intermediate layer;
A charging device comprising: a feeder line connecting portion integrally provided at one end portion in the longitudinal direction of the second electrode and having a width in a direction intersecting the longitudinal direction wider than that of the second electrode. . A strip-shaped first electrode;
A strip-shaped second electrode facing the first electrode;
A first intermediate layer having a higher resistivity than the first electrode, provided on a surface of the first electrode facing the second electrode;
A second intermediate layer provided between the first intermediate layer and the second electrode for preventing conduction;
A hole penetrating the second electrode and the second intermediate layer;
A charging device comprising: a power supply line connecting portion provided integrally with one end portion in the longitudinal direction of the second electrode and having a shape extending from the end portion toward the first electrode side. A strip-shaped first electrode;
A strip-shaped second electrode facing the first electrode;
A first intermediate layer having a higher resistivity than the first electrode, provided on a surface of the first electrode facing the second electrode;
A second intermediate layer provided between the first intermediate layer and the second electrode for preventing conduction;
A hole penetrating the second electrode and the second intermediate layer;
A covering layer for preventing conduction, provided to cover at least one end portion in a longitudinal direction of a laminate including the first electrode, the first intermediate layer, the second intermediate layer, and the second electrode; A charging device comprising:   The distance between the first intermediate layer and the second electrode inside the hole is shorter than the distance between the first intermediate layer and the second electrode outside the hole. 4. The charging device according to any one of 3. A charging device according to any one of claims 1 to 4,
A photoreceptor that is charged by the charging device and whose potential is changed by light irradiation;
An exposure apparatus that irradiates light to the photoconductor based on image data;
A developing device for developing a latent image on the photoreceptor;
An image forming apparatus comprising: a transfer device that transfers an image developed on the photoreceptor to a recording medium.

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