JPH0844191A - Developer carrier, developing device and image forming device - Google Patents

Abstract

PURPOSE:To always obtain a stable image by making it possible for an user to easily recognize a time of replacing a developing device due to the wear of a conductive resin layer installed on the surface of a developer carrier and keeping the developing device in good working order. CONSTITUTION:A developing sleeve 1 is constituted by installing an insulating layer 1b on a conductive sleeve base body 1a, and installing the conductive resin layer 1c on the layer 1b. Thus, when the conductive resin layer 1c having an influence on a developing performance wears, the insulating layer 1b arranged under the layer 1c appears, and on the exposed part of the insulating layer 1b, the appropriate triboelectrostatic charging load necessary for developing is not given to toner, simultaneously, a developing electric field by a developing bias becomes weak by the amount of the absence of the conductive resin layer 1c, or the field is completely eliminated. Thus, the developing performance is drastically reduced, and only the image almost close to a blank paper is obtained, so that the user can clearly recognize that the developing device is used to the limit and the replacing time is here.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic apparatus, a developing apparatus therefor, and a developer carrying member used therein.

[0002]

2. Description of the Related Art FIG. 10 shows an example of a conventional image forming apparatus.

In the figure, reference numeral 101 is a main body of the image forming apparatus, 111 is a latent image carrier installed in the substantial center of the apparatus main body 101, and the carrier 111 is a cylindrical body that rotates in one direction around its axis. It is formed on the photosensitive drum. The charging device 103 is installed at an upper position around the photosensitive drum 111, and the surface of the photosensitive drum 111 is uniformly charged by the charging device 103. Photosensitive drum 111 uniformly charged
Is then imagewise exposed by the exposure device 102 to form a latent image on the surface.

A developing device 104 is installed on the right side of the photosensitive drum 111 in the figure. The developing device 104 holds a magnetic toner 109 as a one-component developer housed in a developing container (hopper) 104 a on a developing sleeve 105 which is a developer carrier, and regulates the toner 109 by an elastic blade 107. After forming a thin layer, the photosensitive drum 111
The toner is supplied to the latent image on the photosensitive drum 111 to develop the latent image and visualize it as a toner image. At the time of development, a developing bias in which an AC voltage is superimposed on a DC voltage is applied between the photosensitive drum 111 and the developing sleeve 105 by a bias power source (not shown).

The toner image on the photosensitive drum 111 obtained by development is transferred to the photosensitive drum 111 by the transfer material 1.
The image is transferred onto the surface 14 by the transfer device 110. Transfer material 11
After being taken out of the cassette 117 by the paper feed roller 116, it is supplied between the photosensitive drum 111 and the transfer device 110 in synchronization with the toner image on the photosensitive drum 111 by a registration roller (not shown). The transfer material 114 on which the toner image has been transferred is conveyed to the fixing device 115, where it is fixed by heat and pressure, and a print recording image is obtained. On the other hand, the surface of the photosensitive drum 111 is the blade 1
Cleaning is performed by the cleaning device 112 including 13 to remove the transfer residual toner on the surface. Then, the photosensitive drum 111 is charged again by the charging device 103, and the above steps are repeated.

FIG. 11 shows details of the magnetic one-component developing device 104. The developing sleeve 105 is formed of a non-magnetic developing sleeve made of a pipe of aluminum or stainless steel, and a magnet 105a, in which a plurality of magnetic poles N and S are alternately formed, is immovable inside the developing sleeve 105 with respect to the rotation of the developing sleeve 105. It is arranged. On the surface of the developing sleeve 105, in order to stabilize the triboelectrification of the magnetic toner 109 and to improve the developing property such as increasing the concentration and reducing the sleeve ghost, the volume resistivity containing conductive fine particles is 10 ⁻³ to 10 ²
A conductive resin layer of Ωcm is provided with a predetermined film thickness.
For example, the conductive resin layer is formed by applying a phenol resin in which carbon is dispersed on the surface of the developing sleeve to a thickness of about 10 μm.

The elastic blade 107 is made of a rubber material such as urethane rubber or silicone rubber, or an elastic metal such as SUS or phosphor bronze. The elastic blade 107 is a supporting sheet metal 1.
By fixing the developing container 104a at a position above the developing sleeve 105 by 0a, the surface of the developing sleeve 105 is contacted with a predetermined pressure.

In the image forming apparatus, the consumable item having the shortest cycle is the toner 109 of the developing device 104. Therefore, the toner 109
When the remaining amount of toner in the developing container 104a is reduced to a predetermined value due to consumption, the remaining amount detection device installed in the image forming apparatus detects that there is no toner and notifies the user.

The remaining amount detecting device has a conductive wire 106 arranged in the developing container 104a in parallel with the longitudinal direction of the developing sleeve 105, and the wire 106 is generated by an AC bias applied to the developing sleeve 105. Development sleeve 1
The detection circuit of the detection device detects the remaining amount of toner by the change in the electrostatic capacitance between the sensor No. 05 and No. 05, and when the absence of toner is detected, the user is notified of that fact.
The user thereby knows the need to replenish the toner,
Toner supply can be started immediately. Toner supply is performed by opening an openable / closable lid 108 provided on the upper part of the developing container 104a and passing therethrough.

[0010]

By the way, the developing device 1
The life of 04 itself is generally set in advance as a predetermined number of images that can be formed, and is judged by a service person or a user based on the number of images formed by a counter provided in the image forming apparatus. Alternatively, the device itself determines. When it is determined that the life has been reached, the developing device 10
4 is replaced by a new one.

However, the preset life of the developing device 104 is a mere guide, and in reality, it considerably depends on the usage situation of the user. That is, the developing sleeve 10
The property of the conductive resin layer on the surface of 5 has the greatest influence on the developing performance, and the life of the developing device depends on the degree of wear of the conductive resin layer.

The conductive resin layer on the surface of the developing sleeve 105 is the nominal value of the developing device for normal use, that is, when the toner is present between the elastic blade 107 and the developing sleeve 105. It is designed to fully satisfy the life. However, even after it is detected that there is no toner, many users continue to use the toner without replenishing it. If this state continues, there is no toner on the developing sleeve 105, the developing sleeve 105 and the elastic blade 107 directly rub against each other, and the conductive resin layer on the developing sleeve surface is rapidly worn. Therefore, even before the nominal life of the developing device is reached, if the conductive resin layer on the surface of the developing sleeve is worn, the developing ability of the developing device cannot be achieved. .

The user has no understanding of the state of the developing sleeve, and unless he / she feels it is a fatal image defect,
There was a possibility of using the developing device as it was until the nominal life. However, the aluminum sleeve is exposed on the surface of the developing sleeve without the conductive resin layer, and the developing performance is better than that with the conductive resin layer in terms of image density / stability, sleeve ghost, etc. Since it is much lower, the user may not be able to enjoy the original performance of the image forming apparatus and may continue to use it. Further, if the developing device is in such a state, there is a possibility that a user who replenishes the toner without noticing it may be disadvantageous in that the replenishment toner is also wasted.

It is an object of the present invention to allow a user to easily know when to replace a developing device due to wear of a conductive resin layer provided on the surface of a developer carrier, and a developer carrier. It is an object of the present invention to provide a developing device using the developer bearing member, and an image forming apparatus including the developing device.

[0015]

The above object can be achieved by the developer carrying member, the developing device and the image forming apparatus according to the present invention. In summary, the present invention is a developer carrying member characterized in that an insulating layer is provided on a conductive substrate, and a conductive resin layer is provided thereon. According to the present invention, the insulating layer can be provided in a planar shape. Further, the surface of the planar insulating layer has a convex portion or a concave portion, and each of the convex portion and the concave portion can be formed in a pattern shape or a shape showing a message. Alternatively, the insulating layer itself may be provided on the convex portion having a pattern or a message.

Another embodiment of the developer carrier of the present invention is a developer carrier characterized in that a conductive resin layer is provided on an insulating substrate. According to the present invention, it is possible to form a convex portion or a concave portion on the surface of the base body, and form each of the convex portion and the concave portion in a pattern form or a form showing a message.

According to another aspect of the present invention, a developer is carried on a developer carrying body and is carried toward a developing area facing the image carrying body, and is regulated by an elastic regulating member during the carrying, In a developing device for forming a thin layer of a developer, the above-mentioned developer carrying member is used as the developer carrying member.

Still another aspect of the present invention is an image forming apparatus in which an electrostatic latent image is formed on an image bearing member and the electrostatic latent image is developed by a developing device using a developer. An image forming apparatus using the above-mentioned developing device.

[0019]

EXAMPLES The feature of the present invention resides in that an insulating layer is present under the conductive resin layer on the surface of the developer carrying member. According to such a developer carrying member, when the conductive resin layer that influences the developing performance is worn, the lower insulating layer appears, and the exposed portion of the insulating layer has different friction charging characteristics from the conductive resin layer,
The proper triboelectric charge required for development cannot be obtained in the toner. At the same time, in the exposed portion of the insulating layer, the developing electric field due to the developing bias also weakens or disappears altogether due to the absence of the conductive resin layer. For this reason, the developing ability sharply decreases, and only an image close to a blank sheet can be obtained, so that the user can clearly know that the life of the developing device has expired.

The present invention will be described below with reference to examples.

Embodiment 1 FIG. 1 is a sectional view showing a developing device in an embodiment of the present invention, FIG. 2 is a sectional view showing a developing sleeve provided in the developing device of FIG. 1, and FIG. 3 is a developing sleeve. FIG. 4 is an image forming apparatus in which the developing device of FIG. 1 is installed, and the configuration of this image forming apparatus is the same as that of the conventional image forming apparatus shown in FIG. 10 except that the developing device 4 of FIG. 1 is provided. Since they are basically the same, the same members in FIG. 4 as those in FIG. 10 are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 1, the developing device 4 according to one embodiment of the present invention is similar to the conventional developing device of FIG. 11 in that it contains a developing container (hopper) 4a containing a magnetic toner 3 of a one-component developer. A developing sleeve 1 as a developer carrying member is provided therein, and the developing sleeve 1 is rotatably installed in an opening portion of the developing container 4 desired for the photosensitive drum 1. In the developing sleeve 1, a magnet 7 in which a plurality of magnetic poles N and S are alternately formed is fixedly installed. In the developing container 4a, a conductive wire 6 which is a detecting means of the toner remaining amount detecting device is installed in parallel with the longitudinal direction of the developing sleeve 1.

Further, the elastic blade 2 is provided above the developing sleeve of the developing container 4 by adhering it to the supporting metal plate 2a.
Is fixed, and the elastic blade 2 is in contact with the surface of the developing sleeve 1 with a predetermined pressure. The elastic blade 2 is made of a rubber material such as silicone rubber or urethane rubber, or an elastic metal such as SUS or phosphor bronze.

The developing sleeve 1 carries the toner 3 in the developing container 4a and rotates to carry the toner toward the developing portion facing the photosensitive drum 111 in FIG. The toner 3 carried on the developing sleeve 1 has its layer thickness regulated when passing through a portion where the elastic blade 2 contacts,
As a result, a thin toner layer is formed on the developing sleeve 1. Further, at the time of this regulation, the toner on the developing sleeve 3 acquires a triboelectric charge having a polarity for developing the latent image by friction with the developing sleeve 1 and the elastic blade 2. The toner formed in a thin layer on the developing sleeve 1 adheres to the latent image on the photosensitive drum 111 under application of a developing bias to the developing sleeve 1 by a bias power source (not shown) in the developing section, and the latent image is formed as a toner image. Visualize as.

The construction of the developing sleeve 1 in this embodiment will be described in detail with reference to FIGS. In FIG. 2, reference numeral 1a indicates a conductive sleeve base, and the developing sleeve 1 of this embodiment has an insulating layer 1b provided on the sleeve base 1a.
A conductive resin layer 1c is provided thereon.

The sleeve base 1a is made of a conductive metal or a resin added with a conductivity-imparting agent. Insulation layer 1
b is formed of a high resistance resin or rubber. Insulation layer 1
The resin or rubber used for b has a volume resistivity of 10 ¹² Ωc.
There is no particular limitation as long as it is m or more, but the use of a material that imparts a charge having a polarity opposite to that of the latent image unsuitable for development to the toner due to friction with the toner 3 further deteriorates the developing performance of the toner. Is more preferable because it can be obtained.

As the material of the insulating layer 1b, specifically,
Various resin materials such as polyurethane, polyester, polycarbonate, polyamide, polyimide, urea, melamine, polyethylene, polypropylene and Teflon, and rubber materials such as isoprene, styrene, nitrile, chloroprene, urethane, silicone and fluorine can be used. The effect can be obtained.

In order to enhance the effect of reducing the developing ability of the toner by the insulating layer 1b described above, in order to give the toner a charge having a polarity opposite to that of the latent image, when the toner is a negative toner, a Teflon resin (rubber) is used. However, in the case of positive toner, nylon resin is preferable. However, when a material having a high mold release property such as Teflon is used for the insulating layer 1b, the insulating layer 1b
Insulating layer 1b by providing a primer layer on the upper and lower surfaces of b
It is necessary to increase the adhesive force between the conductive resin layer 1c and the sleeve base 1a which are in contact with each other.

The insulating layer 1b needs to have a thickness of at least about 5 μm. If it is thinner than this, the insulating layer 1
It becomes difficult to form b uniformly. On the other hand, the insulating layer 1
When the thickness of b is 500 μm or more, it is difficult to obtain the original accuracy such as straightness and roundness of the developing sleeve 1, so the thickness is up to about 500 μm.

The conductive resin layer 1c is made of a resin containing conductive fine particles and has a volume resistivity of 1
It is adjusted with conductive fine particles so as to be about 0 ⁻³ to 10 ² Ωcm. Specific examples of the resin used for the conductive resin layer 1c include phenol, urethane, polyester, polycarbonate, polyamide, polyimide, urea, melamine, polyethylene, polypropylene and Teflon resin. Specific examples of the conductive fine particles include carbon black, graphite, ZnO, SnO ₂ , TiO ₂
Etc.

When the conductive resin layer 1c is formed on the surface layer of the developing sleeve 1 in this manner, the conductive fine particles reduce the contact resistance with the toner on the surface of the developing sleeve 1, and even when the toner is overcharged, its excess charge is increased. Since it is possible to leak the toner, it is possible to stabilize the triboelectric charge of the toner and reduce the mirroring force acting on the toner in the direction of the developing sleeve, and prevent the sleeve ghost caused by excessive charging of the toner. Further, it becomes possible to enhance the developability.

As shown in FIG. 3, the structure of the insulating layer 1b and the conductive resin layer 1c in the longitudinal direction of the developing sleeve 1 is such that the insulating layer 1b is provided on the sleeve base 1a in the image region width and the insulating layer 1b is formed. The conductive resin layer 1c is provided so as to surround the peripheral surface and both end surfaces. Both ends of the sleeve base 1a are bearing portions 1a ', which are supported by bearings (not shown).

According to the above structure, both ends of the conductive resin layer 1c are in contact with the conductive sleeve base 1a, so that the conductive resin layer 1c is the same as the sleeve base 1a to which the developing bias is applied. Can be at electric potential. The application of the developing bias to the developing sleeve 1 is performed on the sleeve base 1a via a sliding contact (not shown).

A specific example of this embodiment will be described.

In this embodiment, an aluminum pipe having a diameter of 16 mm was used for the sleeve base 1a, and a phenol resin was solvent-coated on the sleeve base 1a to form the insulating layer 1b with a thickness of about 50 μm. Further, a resin solution prepared by dispersing an appropriate amount of carbon black fine particles and graphite fine particles as conductive fine particles in a phenol resin is applied to a thickness of about 10 μm and heat-cured to form a conductive resin layer 1c. A developing sleeve 1 according to the present invention was produced.

In the developing sleeve 1, 600-800
A magnet 7 having four Gauss magnetic poles is arranged (800 Gauss magnetic pole of the magnet 7 (a developing pole is arranged) at a position facing the photosensitive drum 111. As the elastic blade 2, a thickness of about 1.
A blade made of urethane rubber having a height of 3 mm and an altitude of 65 ° (JIS-A) is used, and a linear pressure of 20 g is applied to the surface of the developing sleeve 1.
Contact was made with a pressure of / cm. Toner 3 contains styrene-
100 parts by weight of magnetite was kneaded with acrylic resin and pulverized to use a magnetic toner having a particle size distribution center of 5 to 8 μm. 1.2% by weight of silica as an external additive was added to this to obtain a negative charge. I used it as a sex.

Under the above conditions, the developing device 4 was used in the image forming apparatus of FIG. 4 to perform continuous image formation. as a result,
When the developing device is used, the toner is replenished each time the remaining amount detecting device of the image forming device detects that the toner is absent.
Since the conductive resin layer on the surface of the developing sleeve was abraded and the lower insulating layer started to be exposed at the time of performing 00 sheets,
Partial density loss occurred in the image. As the number of formed images increases, the ratio of the density-decreased portion to the image increases, and at the time of image formation of about 1000 sheets, the conductive resin layer disappears over the entire surface of the developing sleeve, and the density cannot be obtained over the entire area, so that a white paper is not obtained. Became closer to. Therefore, it was possible to reliably know that the developing device had reached the end of its life.

On the other hand, when the developing device is used for image formation without replenishing the toner even after it is detected that the toner is absent, it is detected from the detection that the toner is exhausted by about 1
At the time of forming an image on about 00 sheets, the conductive resin layer on the surface layer of the developing sleeve almost disappeared due to abrasion. After that, almost no image was obtained even if the toner was replenished, and similarly, it was possible to certainly know that the developing device reached the end of its life.

As described above, according to the present embodiment, when the developing device reaches the end of its life, an image close to a blank sheet appears, so that the user can clearly know that the developing device has reached the end of life. When it is known that the toner has reached the end of its life after replenishing toner, the developing device is replaced with the replenished toner, and the toner is wasted.

Therefore, as shown in FIG. 5, if the developing device 4 has a divided structure, it is possible to minimize the toner loss. That is, the developing device 4 is connected to the broken line 10
Block 4A on the side including the developing sleeve 1 etc.
And the block 4B on the side only containing the toner 3 are detachably divided into two, and the block 4A on the side including the developing sleeve 1 etc. is replaced with a new developing unit as one developing unit. Make it possible. Sealing members 8 and 9 for preventing toner from spilling at the time of replacing the developing unit are provided near the detachable portions of the blocks 4A and 4B.
To provide. The seal members 8 and 9 are slidable in the same direction as the longitudinal direction of the developing sleeve 1. After the seal members 8 and 9 are pushed into the blocks 4A and 4B to seal the detachable parts of the blocks 4A and 4B, , The developing unit designated as the block 4A may be replaced.

In the above embodiments, the case where the one-component developer made of magnetic toner is used as the developer is shown. However, if the toner is charged by frictional charging, the one-component development made of non-magnetic toner is used. An agent or a two-component developer including a non-magnetic toner and a magnetic carrier may be used, and the same effect can be obtained.

Embodiment 2 FIG. 6 is a sectional view showing a developing sleeve in another embodiment of the present invention, and FIG. 7 is a longitudinal sectional view of the developing sleeve.

As shown in FIG. 6, in the developing sleeve 11 in this embodiment, instead of providing an insulating layer on the sleeve base 11a, the sleeve base 11 itself is made insulative, and a conductive resin is formed on the insulating sleeve base 11a. A layer 11b is provided. Both ends of the sleeve base 11a are bearing portions 11a ', which are received by bearings (not shown).

The conductive resin layer 11b is the sleeve base 11
The sliding contact 15 is provided on the surface a of the conductive resin layer 11b so as to sufficiently cover the image area, and the sliding contact 15 is brought into contact with the surface of the conductive resin layer 11b outside the area corresponding to the image area. A developing bias is applied to the conductive resin layer 11b. Since the sliding contact 15 is in contact with the surface of the conductive resin layer 11b that is easily scraped, it is preferable to use, for example, a conductive brush or the like having a relatively weak elasticity.

For the conductive resin layer 11b, the same material as the conductive resin layer 1c of the first embodiment can be used. The insulating sleeve base 11a needs to be made of a material having strength and precision equivalent to those of a metal sleeve and having an insulating property. Therefore, an engineering plastic having a high strength and a volume resistivity of 10 ¹² Ωcm or more is preferable, and examples thereof include polyacetal, polycarbonate, polybutylene terephthalate, polyimide, polyamide, polyphenylene sulfide resin and the like, or fiber-reinforced products thereof.

According to this embodiment, the developing sleeve 11 has only two layers, which is advantageous in that the structure is simple and the manufacturing is easy. Further, since the developing bias is applied only to the conductive resin layer 11b, the developing electric field cannot be obtained at the portion where the conductive resin layer 11b disappears due to wear. Therefore, the decrease in the developing power can be further increased as compared with the case of the first embodiment, and the user can be more surely notified of the life of the developing device.

Embodiment 3 FIG. 8 is a longitudinal sectional view showing a developing sleeve in still another embodiment of the present invention. In the developing sleeve 13 in this embodiment, an insulating layer 13b is provided on a conductive sleeve base 13a with a width of an image region, and a conductive resin layer 13c is provided so as to surround the peripheral surface and both end surfaces of the insulating layer 13b. The structure and materials used are almost the same as in the first embodiment. The feature of the present embodiment is that the insulating layer 13b has a convex portion 13b 'on its surface, and the convex portion 13b' has a pattern or a message for the insulating layer 13b formed in a planar shape with the width of the image region. That is, it is formed into the shape shown. It is preferable that the convex portion 13b 'is formed on the surface at the same time as a part of the insulating layer 13. However, the same insulating material as the insulating layer 13 or another insulating material is used, and the convex portion 13b' is formed separately on the surface of the insulating layer 13 later. You can also do it.

By using the developing device, the conductive resin layer 13c
When the abrasion occurs, the convex portion 13b 'first appears in the insulating layer 13b, so that an image having a pattern-shaped or message-shaped missing portion due to the convex portion 13b' can be obtained. Therefore, the user can more easily know that the developing device has reached the end of its life, as compared with the above-described first and second embodiments.

The thickness of the convex portion 13b 'needs to be equal to or more than the thickness unevenness of the insulating layer 13b, and the thickness of 10 .mu.m or more is necessary for clearly recognizing the pattern or message by the convex portion 13b'. Therefore, the thickness of the conductive resin layer 13b is required to be thicker than that of the convex portion 13b '.
15 μm or more was necessary.

The pattern of the convex portion 13b 'and the form of the message are, for example, vertical stripes, horizontal stripes and spirals in the pattern.
There are no particular restrictions on the message as long as it is easy for the user to recognize, such as the characters "CHANGE DEVEROPER".

In this embodiment, the pattern or message of the convex portions 13b 'is provided on the surface of the insulating layer 13b.
A pattern of recesses or a message may be provided on the surface of the insulating layer 13b, and the same effect can be obtained. It is also possible to provide a pattern or message of convex portions or concave portions on the surface of the insulating sleeve substrate 11a of the developing sleeve 11 in the second embodiment shown in FIGS. 6 and 7, which is also effective. In the embodiment, as shown in FIG. 9, convex portions 14b made of an insulating material are provided on the surface of a conductive sleeve substrate 14a in a pattern or in a message form, and a conductive resin layer 14b is provided on the convex portions 14b in the width of the image region. The developing sleeve 14 is configured.

Even with the developing sleeve 14 as described above,
The user can easily know that the developing device has reached the end of its life due to the pattern-shaped or message-shaped image loss due to the convex portion 14 b.

[0053]

As described above, in the present invention, since the insulating layer is present under the conductive resin layer on the surface of the developer carrying member, when the conductive resin layer that affects the developing performance is worn, the lower layer is formed. In the exposed portion of the insulating layer, the proper triboelectric charge necessary for development cannot be obtained in the toner, and at the same time, the developing electric field due to the developing bias is weakened by the absence of the conductive resin layer. It ’s all gone. For this reason, the developing ability is drastically reduced, and only an image close to a blank sheet can be obtained, so that the user can clearly know that the life of the developing device has expired and it is time to replace it. Further, by providing convex portions or concave portions on the surface of the insulating layer in a pattern or message form, or by placing the insulating layer itself on the convex portions in a pattern or message form, the user can further clarify the replacement time of the developing device. I can know. Therefore, a stable image can always be obtained by replacing the developing device and performing proper operation without delaying the time.

[Brief description of drawings]

FIG. 1 is a sectional view showing a developing device according to an embodiment of the present invention.

2 is a cross-sectional view showing a developing sleeve provided in the developing device of FIG.

FIG. 3 is a longitudinal sectional view of the developing sleeve of FIG.

FIG. 4 is a sectional view showing an image forming apparatus in which the developing device of FIG. 1 is installed.

5 is a cross-sectional view showing that the developing device of FIG. 1 has a divided structure.

FIG. 6 is a sectional view showing a developing sleeve according to another embodiment of the present invention.

7 is a longitudinal sectional view of the developing sleeve of FIG.

FIG. 8 is a longitudinal sectional view showing a developing sleeve according to still another embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing a developing sleeve according to still another embodiment of the present invention.

FIG. 10 is a sectional view showing a conventional image forming apparatus.

FIG. 11 is a cross-sectional view showing a conventional developing device.

[Explanation of symbols]

 1, 11, 13, 14 Developing sleeve 1a, 13a, 14a Conductive sleeve base 1b, 13b Insulating layer 1c, 11b, 13c Conductive resin layer 2 Elastic blade 3 Magnetic toner 6 Conductive wire rod 7 Magnet 11a Insulating Sleeve base 13b ', 14b Convex portion 15 Sliding contact

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Junichi Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masashi Ojima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoshi Inami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. In-house (72) Inventor Tetsuya Sano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Atsutoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Seiji Yamaguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (10)

[Claims] 1. A developer carrier comprising an electrically conductive substrate, an insulating layer provided on the electrically conductive substrate, and an electrically conductive resin layer provided on the insulating layer. 2. The developer carrying member according to claim 1, wherein the insulating layer is provided in a planar shape. 3. A convex portion is provided on the surface of the planar insulating layer,
3. The developer carrying member according to claim 2, wherein the convex portion is formed in a pattern form or a form showing a message. 4. A recess is formed on the surface of the planar insulating layer,
3. The developer carrying member according to claim 2, wherein the concave portion is formed in a pattern shape or a shape indicating a message. 5. The developer carrier according to claim 1, wherein the insulating layer is provided on a convex portion having a pattern or a message. 6. A developer carrying member, characterized in that a conductive resin layer is provided on an insulating base. 7. The developer carrying member according to claim 6, wherein the substrate has a convex portion on the surface thereof, and the convex portion is formed in a pattern form or a form showing a message. 8. The developer carrying member according to claim 6, wherein the substrate has a recess on the surface thereof, and the recess is formed in a pattern form or a form showing a message. 9. A developer carrying member is carried on a developer carrying member and is carried toward a developing area facing the image carrying member, and is regulated by an elastic restricting member during the carrying process to form a thin layer of the developer. In the developing device to be formed, the developer carrying member according to claim 1, 2, 3, 4, 5, 6, 7 or 8 is used as the developer carrying member. 10. An image forming apparatus for forming an electrostatic latent image on an image bearing member and developing the electrostatic latent image by a developing device using a developer, wherein the developing device according to claim 9 is used as the developing device. An image forming apparatus characterized by being used.