JPH0882993A - Developer carrier, developing device, processing unit, processing cartridge and image forming device - Google Patents

Abstract

PURPOSE: To clearly inform a user of the wear state of a developer carrier and to facilitate the replenishment of developer and the replacement of a developing device. CONSTITUTION: A wear degree measuring area whose light reflectance and conductivity are different from a conductive resin layer 1b is provided under the conductive resin layer 1b in a developing sleeve (developer carrier) 1 having the conductive resin layer 1b. An image forming device provided with the developing sleeve 1 having the conductive resin layer 1b is provided with a reflected light quantity detecting device (wear degree measuring means) 8 measuring the wear degree of the conductive resin layer 1b and a wear warning means. Since a specific measuring area where the wear degree of the conductive resin layer 1b of the developing sleeve 1 is easily detected is provided, the wear state of the developing sleeve 1 is more precisely estimated and the replenishment of the toner (developer) 3 and the replacement of the developing device 4 are facilitated for the user.

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 recording apparatus and a developer carrier, a developing device, a process unit and a process cartridge used in the image forming apparatus.

[0002]

2. Description of the Related Art FIG. 24 shows an example of a conventional image forming apparatus. The image forming apparatus shown in the figure has a structure on the assumption that toner, which is a developer, is replenished.

That is, in FIG. 24, 101 is an image forming apparatus main body, and a process cartridge 118 is detachably mounted in the image forming apparatus main body 101. The process cartridge 118 integrally includes a cylindrical photosensitive drum 111, which is a latent image carrier, and a charging device 103, a developing device 104, and a cleaning device 112 arranged around the photosensitive drum 111. By replacing the cartridge 118 as it is, the maintainability is improved.

By the way, the photosensitive drum 111 rotates in one direction around its axis, and the surface thereof is uniformly charged by the charging device 103, and then a latent image is formed on the surface thereof by the exposure device 102. It

Further, the developing device 104 includes a developing sleeve 105 which is a developer carrier, and itself constitutes a hopper for storing and storing the toner 109 which is a developer, and is provided on the photosensitive drum 111. Toner 109 is supplied to the formed latent image to visualize the latent image as a toner image. A developing blade 107, which is a developer regulating member, is installed near the developing sleeve 105. Then, between the photosensitive drum 111 and the developing sleeve 105,
An appropriate bias in which an AC bias is superimposed on a DC bias is applied from a bias supply power source (not shown).

On the other hand, the transfer material 11 is fed from the paper cassette 117.
4 is supplied by the paper feed roller 116, and the transfer material 11
Reference numeral 4 denotes a photosensitive drum 111 by a registration roller (not shown).
The toner image on the photosensitive drum 111 is transferred onto the transfer material 114 by the action of the transfer device 110 in synchronization with the above toner image. And
The transfer material 114 that has received the transfer of the toner image is a fixing device 115.
The toner image is fixed by heat and pressure in the fixing device 115, and finally the image forming apparatus main body 1
01 is discharged to the outside.

Incidentally, the toner 109 remaining on the photosensitive drum 111 without being transferred to the transfer material 114 in the transfer process.
Is the cleaning device 11 having a blade 113
2, the surface of the photosensitive drum 111 is charged again by the charging device 103, and the above steps are repeated.

Therefore, in such an image forming apparatus,
In order to improve maintainability, the process cartridge 118 may be detachably attached to the image forming apparatus main body 101 as described above, or the developing device 104 may be detachable as a process unit.

FIG. 25 shows the details of an example of the developing device 104 using a magnetic one-component developer.

In FIG. 25, reference numeral 105b designates a non-magnetic developing sleeve as a developer carrying member composed of an aluminum or stainless steel pipe, in which a magnet 105a having a plurality of magnetic poles N and S formed alternately. Are arranged immovably with respect to the developing sleeve 105b. Then, on the surface of the developing sleeve 105b, for the purpose of improving the developing performance (increasing the density, reducing the sleeve ghost), the volume resistance 10 ² containing conductive fine particles for stabilizing the triboelectrification of the toner 109 is increased. A conductive resin layer having a predetermined thickness of 10 ⁻³ Ωcm is formed. The conductive resin layer is made of, for example, a resin in which carbon is dispersed in a phenol resin so as to have a layer thickness of about 10 μm.
It is formed by coating the surface of 05b.

Further, at the position on the developing sleeve 105b,
An elastic blade 107a made of rubber such as urethane rubber or silicon rubber or a metal plate spring is in contact with the developer regulating member at a predetermined pressure, and the elastic blade 107a is supported by a supporting metal plate 107b. .

In the image forming apparatus described above, the toner 109 is the shortest consumable item.
When the remaining amount of the toner 109 consumed as the number of printed sheets reaches a predetermined value and the remaining amount detecting device detects the toner-free state, the user is notified of that. Here, in the remaining amount detecting device, for example, the electrostatic capacitance generated by the AC bias applied to the developer sleeve 105b causes the conductive wire material 106 and the developing sleeve 105 to generate a capacitance.
It is composed of a detection circuit for detecting between b and b. The wire rod 106 is arranged parallel to the developing sleeve 105b in the longitudinal direction.

When the toner-free state is detected and the user is informed of the fact, the user replenishes the toner for replenishment to the developing device 104. To replenish this toner,
For example, an openable / closable lid 1 provided on the upper part of the developing device 104
This is done by opening 08.

On the other hand, the life of the developing device 104 itself is determined as follows. That is, a predetermined number of prints is generally set in advance, and the serviceman or the user himself determines the life of the developing device 104 based on the number of prints displayed on the counter provided in the image forming apparatus, or A method is used in which the apparatus itself judges and instructs replacement, and the developing apparatus 1 judged to have reached the replacement time
04 had been replaced by a new one.

[0015]

In the conventional image forming apparatus of the toner replenishment type, the life of the developing device set in advance is merely a guideline, and the life of the developing device actually depends on the usage situation of the user. It was quite dependent. That is, the life of the developing device depends on the degree of wear of the conductive resin layer on the surface of the developing sleeve, which most affects the life of the developing device. The life of the developing device is designed with a margin so that the conductive resin layer can be sufficiently satisfied in normal use (when toner is present between the elastic blade and the developing sleeve). Has been done.

However, there has been no means for clearly indicating the degree of wear of the conductive resin layer on the surface of the developing sleeve until now. Therefore, many users continue to use the developing device without replacing it. The bare metal is exposed on the surface of the developing sleeve where the conductive resin layer has disappeared due to excessive use, and it is far more in terms of image density, stability, sleeve ghost, etc. than when there was a conductive resin layer. The developing performance will be deteriorated. The user continued to use the image forming apparatus as it was unless he / she felt it was a fatal image defect, and could not enjoy the original performance of the image forming apparatus.

Further, even before the developing device reaches the end of its life, many users continue to use the toner as it is without replenishing the toner even after the absence of toner is detected. If such an inappropriate use condition continues, almost no toner is left on the developing sleeve, and the developing sleeve and the elastic blade directly rub against each other, and the conductive resin layer on the developing sleeve surface is rapidly worn and deteriorated. Will end up. Then, in such a state, the user continues to use the original performance of the image forming apparatus without being able to enjoy it.

In particular, when the conductive resin layer on the surface of the developing sleeve is severely worn or deteriorated, the life of the developing device is extremely shortened, and there is a possibility that a fatal image defect occurs and the image forming apparatus becomes unusable. It was Further, when toner is supplied without noticing that the developing device has reached such a state, there is a possibility that the supplied toner is also wasted.

The present invention has been made in view of the above problems, and an object of the present invention is to inform the user of the state of wear of the developer carrier more clearly, and to prompt replenishment of the developer and replacement of the developing device. An object of the present invention is to provide a developer carrier, a developing device, a process unit, a process cartridge, and an image forming apparatus that can be used.

[0020]

In order to achieve the above object, the invention according to claim 1 provides a developer carrying member having a conductive resin layer, wherein the light reflectance and the electrical conductivity under the conductive resin layer. It is characterized in that an abrasion degree measuring region having a degree different from that of the conductive resin layer is provided.

A second aspect of the present invention is characterized in that, in the first aspect of the invention, the wear degree measurement region is provided in a non-image portion.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a layer having a light reflectance different from that of the conductive resin layer is provided below the conductive resin layer in the wear degree measurement region. Characterize.

According to a fourth aspect of the invention, in the second aspect of the invention, an insulating layer is provided below the conductive resin layer in the wear degree measurement region provided in the non-image portion,
It is characterized in that a detection unit is provided which is electrically insulated from the conductive resin layer in the image area by abrasion of the conductive resin layer.

According to a fifth aspect of the invention, the developer carried on the developer carrying body having a conductive resin layer is regulated by a developer regulating member, and a thin layer of the developer is formed on the developer carrying body. Meanwhile, in the developing device that conveys the developer to the developing region, a wear degree measuring region having a light reflectance and an electric conductivity under the conductive resin layer of the developer carrier different from that of the conductive resin layer is provided. And

According to a sixth aspect of the present invention, in an image forming apparatus including a developer carrying member having a conductive resin layer, a wear degree measuring means and a wear warning means for the conductive resin layer are provided. .

A seventh aspect of the invention is characterized in that, in the sixth aspect of the invention, the wear degree measuring means is a reflected light amount detecting means.

According to an eighth aspect of the invention, in the invention of the seventh aspect, the developer in the measurement area on the developer carrying member is detected on the latent image carrying member in order to detect the reflected light amount of the developer carrying member. It is characterized in that control means for developing is provided.

A ninth aspect of the invention is characterized in that, in the sixth aspect of the invention, the wear degree measuring means is a conductivity detecting means.

According to a tenth aspect of the present invention, there is provided a development comprising a conductive resin layer, and an abrasion degree measuring region having a light reflectance and an electric conductivity different from those of the conductive resin layer under the conductive resin layer. The present invention is characterized in that a process unit is configured to include a developing device equipped with the agent image carrier, and the process unit is attachable to and detachable from the main body of the image forming apparatus.

According to the eleventh aspect of the present invention, there is provided a conductive resin layer, and a development is provided by providing an abrasion degree measuring region below the conductive resin layer, which has a light reflectance and an electric conductivity different from those of the conductive resin layer. A process cartridge is configured to include a developing device equipped with the agent image carrier, and the process cartridge can be attached to and detached from the main body of the image forming apparatus.

[0031]

According to the first aspect of the present invention, since the specific measurement region in which the degree of wear of the conductive resin layer of the developer carrier is easily detected is provided, the wear state of the developer carrier can be more accurately estimated. Therefore, it is possible to notify the user of the timing of toner replenishment and development device replacement accurately.

According to the second aspect of the invention, since the wear degree measuring region is provided in the non-image portion, the image is not affected by the measuring region, and the layer thickness of the conductive resin layer in the measuring region is By freely setting, it is possible to easily control the time when the warning is issued.

According to the third aspect of the present invention, it is possible to utilize that the amount of reflected light largely changes due to abrasion of the conductive resin layer, and it is possible to detect the amount of reflected light more easily and accurately.

According to the fourth aspect of the present invention, the wear degree of the conductive resin layer can be detected more accurately by detecting the change in the DC component of the potential or the current of the detection portion, and the measurement can be performed. By adjusting the thicknesses of the conductive resin layer and the insulating layer in the region, it is possible to easily control the timing of issuing the warning.

According to the fifth aspect of the present invention, it is possible to obtain the developing device capable of detecting the worn state of the developer carrying member.

According to the sixth aspect of the present invention, by providing the wear degree measuring means and the wear warning means, it is detected that the wear degree of the developer carrier exceeds a predetermined value, and the developer is supplied to the user. It is possible to prompt the user to notify the time of replacement of the developing device.

According to the invention of claim 7, the wear and abrasion of the conductive resin layer are grasped as a change in the amount of reflected light, so that the non-contact measurement of the conductivity does not have any influence on the developer carrying member to be measured. It is possible to measure the degree of wear of the resin layer.

According to the eighth aspect of the present invention, the developer which obstructs the measurement when the wear degree of the developer carrier is measured as a change in the amount of reflected light is removed from the measurement position on the developer carrier, and the developer is removed. The wear degree of the carrier can be measured more accurately.

According to the ninth aspect of the present invention, abrasion of the conductive resin layer can be accurately, easily, and continuously detected by the conduction detection.

According to the tenth aspect of the present invention, it is possible to obtain a process unit which can detect the wear state of the developer carrying member and is excellent in maintainability.

According to the eleventh aspect of the present invention, it is possible to obtain a process cartridge in which the wear state of the developer carrying member can be detected and which has excellent maintainability.

[0042]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 is a sectional view of an image forming apparatus according to Embodiment 1 of the present invention, and FIG. 2 shows the construction of a control device including a wear degree detecting means and a wear warning means for a conductive resin layer. FIG. 3 is a block diagram, FIG. 3 is a cross-sectional view showing the developing device and the reflected light amount detection device, and FIG.

In the image forming apparatus according to this embodiment, as shown in FIG. 1, a process cartridge 118 is detachably mounted in the image forming apparatus main body 101. This process cartridge 118 is a latent image carrier. A cylindrical photosensitive drum 111 and a charging device 103 arranged around the photosensitive drum 111,
The developing device 4 and the cleaning device 112 are integrally configured.

By the way, the photosensitive drum 111 rotates in one direction around its axis, the surface of the photosensitive drum 111 is uniformly charged by the charging device 103, and then a latent image is formed on the surface thereof by the exposure device 102. It

Further, the developing device 4 is provided with a developing sleeve 1 which is a developer carrying member, and itself constitutes a hopper for storing and storing the toner 3 which is a developer, and is provided on the photosensitive drum 111. Toner 3 is supplied to the formed latent image to visualize the latent image as a toner image. In the vicinity of the developing sleeve 1, a developing blade 2 which is a developer regulating member is provided.
Is installed.

On the other hand, the transfer material 11 is transferred from the paper cassette 117.
4 is supplied by the paper feed roller 116, and the transfer material 11
Reference numeral 4 denotes a photosensitive drum 111 by a registration roller (not shown).
The toner image on the photosensitive drum 111 is transferred onto the transfer material 114 by the action of the transfer device 110 in synchronization with the above toner image. And
The transfer material 114 that has received the transfer of the toner image is a fixing device 115.
The toner image is fixed by heat and pressure in the fixing device 115, and finally the image forming apparatus main body 1
01 is discharged to the outside.

The toner 3 remaining on the photosensitive drum 111 without being transferred to the transfer material 114 in the transfer step is removed by the cleaning device 112 having the blade 113, and the surface of the photosensitive drum 111 is charged by the charging device 103 again. The above steps are repeated.

By the way, the developing device 4 according to the present embodiment is
As shown in FIG. 1, it is provided with an opening 5 for replenishing toner and an antenna wire 6 for detecting the remaining amount of toner, and is configured to issue a warning of no toner. In this embodiment, since the toner 3 has a single magnetic component, a magnet 7 for holding the toner 3 is installed inside the developing sleeve 1.

Further, as shown in FIG. 1, a reflected light amount detecting device 8 is provided in the image forming apparatus main body 101, and the reflected light amount detecting device 8 includes a light emitting portion 8a, a light receiving portion 8b and FIG.
The wear degree detection circuit 8c shown in FIG. As shown in FIG. 2, the wear degree detection circuit 8c gives a warning to the user that the developing sleeve 1 is worn through the control circuit 9 also functioning as a wear degree warning means and the display device 10, or the developing device 4 is used.
Informs you that it is time to replace it.

Next, the developing device 4 and the reflected light amount detecting device 8 will be described in more detail with reference to FIG.

The developing sleeve 1 shown in FIG. 3 is rotatably installed in the opening of the developing device 4, and a magnet 7 in which a plurality of magnetic poles N and S are alternately formed is fixedly installed in the developing sleeve 1. ing. In this embodiment, the magnet 7
The one having four magnetic poles of 600 to 800 gauss was used.

The developing sleeve 1 contains a base material 1a obtained by adding a conductivity-imparting agent to a non-magnetic metal such as aluminum or stainless steel or a resin, and conductive fine particles in the resin, and has a volume resistance of 10 ² to 10 ^{−. The} conductive resin layer 1b is adjusted to have a resistance of about ³ Ωcm.

In this embodiment, an aluminum pipe having a diameter of 16 mm is used as the sleeve substrate 1a, and a resin liquid prepared by dispersing carbon black fine particles and graphite fine particles of conductive fine particles in a phenol resin in an appropriate amount. Was applied to a thickness of about 10 μm, and this was thermally cured to form a conductive resin layer 1b. The conductive resin layer 1b is gray black, has a low light transmittance, and has a thickness of 3 μm.
The light transmittance hardly changes until it reaches a certain level.

By the way, as another example of the conductive resin layer 1b, carbon black, graphite, ZnO, SnO ₂ , TiO ₂ or the like is used as the conductive fine particles, and urethane, polyester, polycarbonate, polyamide, polyimide, or a resin material is used. The thing using urea, melamine, polyethylene, polypropylene, Teflon etc. is mentioned.

Thus, according to the developing sleeve 1 on which the conductive resin layer 1b containing conductive fine particles is formed, the electric contact resistance between the surface of the developing sleeve 1 and the toner 3 is suppressed to a small level, Even when the toner 3 is excessively charged, the conductive fine particles can leak the excessive electrification. Further, by stabilizing the triboelectric charging and reducing the mirroring force acting on the toner 3 in the direction of the developing sleeve 1, it is possible to prevent the occurrence of sleeve ghost due to excessive charging and improve the developing property. The conductive resin layer 1
As b, it is desirable that the transmittance and reflectance of light vary as much as possible depending on the thickness. However, the color and the like are not limited.

A blade 2a made of an elastic member is in contact with the developing sleeve 1 with a predetermined pressure, and the blade 2a is bonded and fixed to a supporting sheet metal 2b. still,
As the blade 2a, for example, a blade made of a rubber material such as silicon rubber or urethane rubber, a metal sheet metal made of SUS or phosphor bronze having elasticity can be used. In this embodiment, the blade 2a has a thickness of about 1.3 mm and a hardness of 6
A 5 ° (JIS-A) urethane rubber material was used, and the contact pressure of the blade 2a with respect to the developing sleeve 1 was set so that the linear pressure was 20 g / cm.

Toner 3 carried on the developing sleeve 1
Has its layer thickness regulated when passing through a portion where the blade 2a abuts, whereby a thin toner layer is formed on the developing sleeve 1. At this time, the toner 3 on the developing sleeve 1 can acquire a triboelectric charge having a polarity for developing the latent image by friction between the developing sleeve 1 and the blade 2a. In this embodiment, the toner 3 is styrene-
To an acrylic resin in which 100 parts by weight of magnetite was kneaded and pulverized so that the center of the particle size distribution was 5 to 8 μm, 1.2 parts by weight of silica was added as an external additive,
The thing which made this the negative electrification property was used.

When a bias is applied to the developing sleeve 1 from the developing bias power source by the control circuit 9 shown in FIG.
When it comes to the position opposite to 1, the latent image on the photosensitive drum 111 is developed as a toner image. The bias is supplied to the developing sleeve 1 through a sliding contact (not shown).

The light emitting portion 8a of the wear measuring device 8 shown in FIG.
Is composed of an LED element, and the light emitting portion 8a emits light in response to a signal from the wear degree detection circuit 8c. On the other hand, the light receiving portion 8b is composed of a phototransistor 8d and an optical lens 8c, in which the light from the light emitting portion 8a is conductive resin layer 1b.
The light reflected on the surface is captured by the optical lens 8e, and the amount of light is converted into an electric signal by the phototransistor 8d. The light emitting section 8a may use a light source such as an incandescent lamp or a laser light oscillation element in addition to the LED element, and an irradiation area may be narrowed down by using an optical lens as necessary.
In addition to the phototransistor, any light-receiving element having high sensitivity such as a photodiode or a CCD element may be used as the light-receiving portion 8b, and the optical lens may be omitted if the light amount can be sufficiently detected. good.

By the way, as described above, the conductive resin layer 1b is formed.
When detecting the amount of reflected light, the toner 3 on the conductive resin layer 1b may be an obstacle. Therefore, in this embodiment, when the amount of reflected light is detected, the control circuit 9 operates the image forming apparatus to control the toner 3 on the developing sleeve 1 on the photosensitive drum 111 for development. In the present embodiment, after the main body power is turned on, the mounting of the developing device 4 is confirmed, or the first standby after the warning of absence of toner is displayed, the entire exposure of the developing sleeve 1 having a width of ¼ circumference is performed. Printing was performed, and during this period, the amount of reflected light was detected on the downstream side of the developing area. If the toner layer on the developing sleeve 1 is thin and the toner layer does not obstruct the detection of the amount of reflected light,
It is not necessary to perform such control.

Here, the detection of the degree of wear of the conductive resin layer 1b will be described in detail.

The surface of the conductive resin layer 1b gradually becomes smooth as it becomes thinner due to abrasion, and the light reflectance of the surface gradually increases. Further, when the conductive resin layer 1b is worn away and light starts to pass through the conductive resin layer 1b, the transmitted light is reflected by the aluminum of the base material 1a and the amount of reflected light is further increased.

Therefore, the amount of reflected light converted into an electric signal by the light receiving portion 8b of the wear degree detecting device 8 is discriminated by the wear degree detecting circuit 8c as to whether it is larger or smaller than a predetermined threshold value. The degree of wear can be detected.

When the wear degree detection circuit 8c determines that the wear degree (reflected light amount) exceeds a predetermined threshold value, a signal is sent to the control circuit 9 and the control circuit 9 causes the display device 10 to display. It outputs a warning such as "The developing sleeve is worn" or an instruction such as "Replace the developing device" or a display meaning that.

FIG. 4 shows the transition of the reflected light amount (wearing degree) of the conductive resin layer 1b when images are formed by the image forming apparatus according to this embodiment and continuous printing (printing ratio 4%) is performed.
Shown in

In the normal use method in which the toner is replenished according to the toner-out warning every about 3000 sheets, as shown in FIG. 4, the abrasion of the conductive resin layer 1b progresses after about 11500 sheets are passed, and the resin layer Light starts to pass through 1b, and the amount of reflected light starts to increase.

Further, at about 12500 sheets after the fourth toner replenishment, the effect on the image due to the loss of the function of the conductive resin layer 1b due to the abrasion of the conductive resin layer 1b ( Image density reduction, uneven density, sleeve ghost) will start to occur. After that, the density decrease gradually becomes remarkable, and the function of the conductive resin layer 1b is completely lost over the entire area of the developing sleeve 1 at about 13500 sheets, and fatal image defects such as character blurring and blotch appear. It was Therefore, for the fourth toner replenishment, about half the toner is wasted even for the user who thinks that it is sufficient to obtain a character image, and most toner is wasted for the user who desires a high-quality image.

However, in this embodiment, about 1150
By setting the threshold value of the light amount detection circuit so as to detect the increase of the reflected light amount starting at the time of 0 sheets, the user clearly knows that the developing device 4 has reached the end of life before the fourth toner replenishment. Therefore, it is possible to avoid wasteful toner supply.

In the optical measurement of this embodiment, the conductive resin layer 1 was not affected by the developing sleeve 1.
The degree of wear of b can be measured.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 5 is a transverse sectional view of the developing sleeve according to the present embodiment, FIG. 6 is a longitudinal sectional view of the developing sleeve, and FIG. 7 is a diagram showing (a change with time) in the amount of reflected light with respect to the number of passed sheets.

The structure of the image forming apparatus according to the present embodiment is the same as that of the image forming apparatus according to the first embodiment except for the developing sleeve and the power feeding method thereof.

In FIG. 5, a developing sleeve 11 which is a developer carrying member is a sleeve base material 11 made of metal or engineering plastic having strength and accuracy equivalent to those of metal.
a, a light reflection layer 11b provided thereon, and a conductive resin layer 11c further provided thereon.

However, when the engineering plastic is used for the sleeve base material 11a, the conductive resin layer 11 is used.
In order to ensure conduction to c, a developing bias is applied by a sliding contact 12 in a portion outside the image range. Since the sliding contact 12 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 relatively weak elasticity. Examples of engineering plastics include polyacetal, polycarbonate, polybutylene terephthalate,
Polyimide, polyamide, polyphenylene sulfide, or the like, or fiber-reinforced products thereof are used. In this example, fiber-reinforced polyacetal was used for the sleeve substrate 11a.

By the way, the light reflection layer 11b is a layer of an insulating resin in which a white pigment is dispersed, and the resin material is
Polyurethane, polyester, polycarbonate, polyamide, polyimide, urea, melamine, polyethylene, polypropylene, Teflon, etc. are used. In this embodiment, as the white pigment, a resin solution prepared by dispersing ZnO ₂ fine particles in an appropriate amount in a phenol resin and applied to a thickness of about 3 μm, and thermally cured was used. The conductive resin layer 11c is a layer obtained by applying a phenol resin solution in which carbon and graphite having the same formulation as in Example 1 are dispersed to a thickness of about 10 μm and thermally curing the same.

The developing sleeve 1 having the above structure
FIG. 7 shows changes in the abrasion of the conductive resin layer 11c and the amount of reflected light when No. 1 is used. The measurement was carried out in the same manner as in Example 1 by a regular usage method in which toner was replenished in accordance with a toner-free warning every about 3000 sheets.

The increase in the amount of reflected light due to the progress of abrasion of the conductive resin layer 11c begins earlier than Example 1 at about 11200 sheets due to the provision of the light reflecting layer 11b, and the amount of change also increases. There is. At the time of about 12000 sheets, the influence on the image (decrease in density, uneven density, sleeve ghost) starts to occur due to the appearance of the lower light reflection layer 11b due to the abrasion of the surface conductive resin layer 11c, and thereafter. The density decrease rapidly became remarkable, and almost no image appeared at the time of about 12,500 sheets. In this embodiment, the transition of the change of the reflected light amount is similar to that of the first embodiment, but the absolute value and the change amount of the reflected light amount become large, so that the wear degree can be detected more accurately.

The purpose of this embodiment is to provide a portion of the developing sleeve 11 under the conductive resin layer 11c, which has a light reflectance significantly different from that of the conductive resin layer 11c, so as to detect the degree of wear of the conductive resin layer 11c. To make it easier.

Therefore, the light reflecting layer 11b is not limited to the resin material, but rubber materials such as isoprene, styrene, nitrile, chloroprene, urethane, silicon, and fluorine may be used. There is no problem whether the light reflection layer 11b is insulative or conductive. Further, the light reflection layer 11b may be omitted if the light reflectance of the sleeve base material 11a is sufficiently high. In this case, since the layer structure is only two layers, there is an advantage that the structure is simple and the manufacturing is easy.

As a matter of course, the developing sleeve 11 of this embodiment
The developing device having the above may be configured as a process unit so as to be easily attached and detached, or the developing device, the photosensitive drum, the charging device, the cleaning device, and the like may be combined to form a process cartridge for easy maintenance.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. 8 is a transverse sectional view of the developing sleeve according to the present embodiment, FIG. 9 is a longitudinal sectional view of the developing sleeve, and FIG. 10 is a view showing a change (change with time) in the amount of reflected light with respect to the number of passed sheets.

The structure of the image forming apparatus according to this embodiment is the same as that of the image forming apparatus according to the first embodiment except for the developing sleeve and the power supply method for the developing sleeve.

The developing sleeve 13 which is the developer carrying member according to this embodiment is a sleeve base material 13 made of metal or engineering plastic having strength and accuracy equivalent to those of metal.
a, a conductive light reflection layer 13b provided thereon, and a conductive resin layer 13c further provided thereon.

In this embodiment, aluminum is used as the sleeve base material 13a, and the conductive resin layer 13 as the surface layer is formed thereon.
A conductive light reflection layer 13b having a light reflectance different from that of c was provided. As the surface conductive resin layer 13c, the conductive resin layer 13c described in Example 1 was used.
A phenol resin solution in which carbon and graphite having the same formulation as in the above is thermally cured is used.

The conductive light-reflecting layer 13b has an appropriate amount of conductive fine particles of SnO ₂ and TiO ₂ and graphite particles dispersed in a phenol resin so as to have substantially the same volume resistance and charging characteristics as the conductive resin layer 13c. It is prepared, applied and heat-cured. The conductive light reflection layer 13b has a grayish white color and is slightly more easily worn than the conductive resin layer 13c. In this embodiment, the conductive resin layer 11c
The thickness of each of the conductive light reflection layer 11b and the conductive light reflection layer 11b was set to 6 μm.

FIG. 10 shows the transition of the amount of reflected light (degree of wear) of the conductive resin layer 11c when the developing sleeve 13 having the above structure is used.

As shown in FIG. 10, in the normal usage in which the toner is replenished in accordance with the toner-out warning every about 3,000 sheets, about 850 before the third toner replenishment.
The amount of reflected light starts to increase from 0 sheets due to the abrasion of the conductive resin layer 13c, and at about 9500 sheets, the surface conductive resin layer 11c is almost worn away. At about 12,500 sheets after the fourth toner replenishment, the effect on the image due to the loss of the function of the conductive resin layer 11c due to the abrasion of the conductive light reflecting layer 11b (the image having a large printing area) Density decrease, density unevenness, sleeve ghost). After that, the decrease in concentration became more and more remarkable, and about 1
At the time of 3,500 sheets, the function of the conductive light-reflecting layer 11b was completely lost over the entire area of the developing sleeve 13, and fatal image defects such as blurring of letters and blotches appeared.

In the present embodiment, the conductive resin is adjusted so that the amount of reflected light increases due to abrasion of the conductive resin layer 12c at a time about 3000 sheets printed (one toner replenishment) earlier than the time when the image quality starts to deteriorate. Layer 11c and conductive light reflection layer 11b
Was set. Therefore, the user can clearly know that the life of the developing device is "at most one toner replenishment", and wasteful toner replenishment can be avoided. In addition, even in an improper use condition in which the toner-out warning is ignored and the toner is not replenished, the conductive resin layer 11c is worn away and the life of the developing device is "at most one toner replenishment". Let the user know
It is possible to prompt the “final toner supply”, prevent the continuation of a further inappropriate usage situation, and prevent the life of the developing device from being shortened.

The purpose of this embodiment is to provide a conductive resin layer (conductive light reflection layer) 11b having a different light reflectance under the conductive resin layer 11c of the developing sleeve 13, and to provide the conductive resin layer 11c.
It is to control the detection timing by making it easier to detect the degree of wear and further adjusting the film thicknesses of the upper and lower conductive resin layers 11c and 11b.

Therefore, the upper and lower conductive resin layers 11c and 11 are formed.
Any combination of colors may be used as long as the reflectance of the light b is different and the difference can be easily detected by the light receiving element. Further, the layer structure of the developing sleeve 13 is not limited to the above-mentioned three layers, and may be a multilayer. For example, the sleeve substrate 11
There may be four layers including a and the color of each conductive resin layer may be white-black-white or the like. It is necessary to adjust the charging characteristics and the volume resistance of the conductive resin layers to be substantially the same, but the easiness of abrasion and the film thickness are not limited.

As a matter of course, the developing device having the developing sleeve 13 according to the present embodiment is made into a process unit so as to be easily attached and detached, and the developing device, the photosensitive drum, the charging device, the cleaning device, etc. are provided in order to facilitate maintenance. The process cartridges may be collectively used.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIGS. 11 is a longitudinal sectional view of the developing sleeve according to the present embodiment, FIG. 12 is a perspective view showing a reflected light amount detecting device, and FIG. 13 is a block diagram showing the structure of the wear degree detecting means and the wear degree warning means. FIG. 14 is a diagram showing a change (change with time) in the amount of reflected light with respect to the number of passed sheets,
FIG. 15 is a diagram showing a change (change with time) in the difference in reflected light amount with respect to the number of passed sheets.

As shown in FIG. 11, the developing sleeve 14, which is a developer carrying member, includes a sleeve base material 14a, a photodetection layer 14b provided thereon, and a conductive resin layer further provided thereon. It is composed of three layers 11c. However,
The light detection layer 14b is applied only to a part in the longitudinal direction, and a part having a high light reflectance and a part having a low light reflectance are applied next to each other.

In this embodiment, the sleeve base material 14a and the conductive resin layer 14c are the same as those used in the first embodiment. The light detection layer 14b has S on the portion 14bA having a high light reflectance.
A polyester resin in which carbon black was dispersed in nO ₂ and TiO ₂ and the portion 14bB having a low light reflectance was used. The thickness of the light detection layer 14b was set to 2 μm or less, and the conductive resin layer 14c was applied so that the thickness thereof was about 10 μm. The thickness of the conductive resin layer 14c on the light detection layer 14b is 8 to 9 μm, and there is no step on the surface. The photodetection layer 14b may be insulative, but since image defects are likely to occur as wear progresses, the photodetection layer 14b is made conductive in this embodiment. However, the volume resistance and the charging characteristics are high reflectivity portion 14b.
A and the low reflectance portion 14bB are different from each other, and the volume resistance and the charging characteristic of the conductive resin layer 11c are not matched.

The high reflectance portion 14bA of the light detection layer 14b.
If the amount of reflected light is measured only in a certain area of, the wear degree can be detected almost in the same manner as in the second embodiment. in this way,
The measurement area may be limited so that the wear degree detection is performed only in a predetermined area on the developing sleeve 14. Even when the toner on the developing sleeve 14 is removed to facilitate the measurement, it is possible to reduce the amount of wasted toner by controlling the exposure of only the portion corresponding to the area to develop the toner. However, it is necessary to improve the measurement position accuracy of the wear degree measuring device 8 ′.

In this embodiment, as schematically shown in FIG. 12, two light receiving portions 8b and 8b 'of an abrasion degree measuring device 8'of the image forming apparatus are provided, and light detection is performed under the conductive resin layer 14c. Each of the layers 14b has a high reflectance portion 14bA and a low reflectance portion 14b.
A certain area of B (areas indicated by A and B in FIG. 12: shown in white and black in the drawing, but of course, since the surface layer is covered with the conductive resin layer 11c, the appearance is not distinguished. It was made possible to measure the amount of reflected light of (not possible) separately. In order to facilitate the measurement, the toner on the developing sleeve 14 in the above area is removed so that only the portion corresponding to the area is exposed to develop the toner. As shown in FIG. 13, the measurement results of the respective light receiving portions 8b and 8b 'are compared by the wear degree detection circuit 8c', and a signal is sent to the control circuit 9 whose difference exceeds a predetermined value, and the control circuit 9 A warning is displayed on the display device 10. The other configurations of the image forming apparatus except for the developing sleeve 14 and the abrasion degree measuring device 8 ′ are the same as those of the image forming apparatus according to the first embodiment.

FIG. 14 shows the transition of the reflected light amount of the high reflectance portion 14bA and the low reflectance portion 14bB when the developing sleeve 14 having the above-mentioned structure is used. The measurement was carried out in the same manner as in Example 1 by a regular usage method in which toner was replenished in accordance with a toner-free warning every about 3000 sheets.

As shown in FIG. 14, the difference in the reflected light amount between the high reflectance portion 14bA and the low reflectance portion 14bB of the light detection layer 14b tends to widen over time, and as shown in FIG. By detecting it, the wear degree can be detected more accurately. For example, the absolute value of the amount of reflected light for each developing sleeve 14 may fluctuate due to the difference in lots of conductive resin liquids, manufacturing conditions, etc. Therefore, in order to prevent erroneous detection, detection can be performed only when the amount of reflected light changes greatly. It was However, by performing the comparison detection as described above, the variation in the absolute value of the reflected light amount can be ignored, and the wear degree can be detected more accurately.

In this embodiment, the light amount detection circuit is set so as to give a warning at a time about 3000 sheets printed (one toner replenishment) earlier than when the image quality starts to deteriorate. With this setting, as shown in the third embodiment, the user can be informed that the life of the developing device is "at most one toner replenishment".

The first purpose of this embodiment is to detect the degree of wear of the conductive resin layer only by providing a specific small measurement area on the developing sleeve, which is easy to detect. Therefore,
It suffices that the light detection layer 14b is provided on a part of the developing sleeve 14, and the manufacturing conditions of the developing sleeve 14 are eased.

The second gist of the present embodiment is to provide a portion where the transition of the reflected light amount is different and compare and detect each. By comparison detection, as described above, the developing sleeve 1
The variation factor of the reflected light amount in manufacturing No. 4 can be ignored.

It is sufficient that the transition of the change in the amount of reflected light can be sufficiently detected in the measurement area, and the configuration is not limited. For example, instead of the light detection layer 14b, the aluminum surface of the sleeve base material 11a may be partially roughened, or conversely, may be partially smoothed to form the reflected light amount measurement unit. The light detection layer 14b does not necessarily have to be applied.

As a matter of course, the developing sleeve 14 of this embodiment
The developing device having the above may be configured as a process unit so as to be easily attached and detached, or the developing device, the photosensitive drum, the charging device, the cleaning device, and the like may be combined to form a process cartridge for easy maintenance.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIGS. 16 is a longitudinal sectional view of the developing sleeve according to the present embodiment, FIG. 17 is a lateral sectional view of the developing sleeve, FIGS. 18 and 19 are views showing changes in the reflected light amount with time, and FIG. 20 is a reflected light amount difference. It is a figure which shows the time-dependent change of.

The developing sleeve 15 according to this embodiment comprises a sleeve base material 15a and a light reflecting layer 15b provided thereon.
And three conductive resin layers 15c provided thereon. However, the light reflection layer 15b is applied only to a part in the longitudinal direction. In addition, the light reflection layer 15
Only a half of the outer circumference of the developing sleeve 15 is coated with b.

In this embodiment, the sleeve base material 15a and the conductive resin layer 15c are the same as those used in the first embodiment, and the light detection layer 15b is made of ZnO ₂ fine particles as a white pigment so that glass fibers can be used to further reflect light. The resin solution prepared by dispersing an appropriate amount of the above in a phenol resin was heat-cured. The light reflection layer 15b was applied so that the thickness thereof was about 5 μm or less. The thickness of the conductive resin layer 15c is about 10 μm. The thickness of the conductive resin layer 15c on the light detection layer 15b is 8 μm, and there is a step on the surface.

Thus, in this embodiment, the light reflecting layer 15 is
The portion outside the image area where b is present becomes the measurement area. In addition, in this embodiment, the length of the blade is extended so that the wear condition of the conductive resin layer 15c in the measurement region well reflects the wear condition of the conductive resin layer 15c in the image region. The other configuration of the image forming apparatus except for the blade and the developing sleeve 15 is the same as that of the image forming apparatus described in the first embodiment.

FIG. 18 and FIG. 1 show the behavior of the amount of reflected light in the measurement area when the developing sleeve 15 having the above configuration is used.
9 shows. In the measurement area, a portion where the light detection layer 15b is provided,
Since the non-existing portion is replaced every half circumference of the developing sleeve 15, the amount of reflected light is as shown in FIG.
Amplitude appears as shown in FIG. Then, the conductive resin layer 1
As the abrasion of 5c increases, the amplitude of the reflected light amount increases as shown in FIG. By detecting this amplitude with the wear degree detection circuit, it is possible to detect the wear degree accurately, which is equivalent to the comparison detection shown in the fourth embodiment and does not depend on the variation factor in manufacturing the developing sleeve 15. . Further, this method has an advantage that only one light receiving portion of the wear degree detecting device is required.

In this embodiment, the surface conductive resin layer 15 is used.
Since c is worn away and the light detection layer 15b is exposed and the difference in the amount of reflected light is increased, it is possible to detect without removing the toner on the surface layer. Therefore, the measurement of the degree of wear of the developing sleeve 15 does not need to be limited to the downstream side of the developing area. Naturally, the setting position of the detection device is not limited as long as the amount of reflected light in the measuring area on the developing sleeve 15 can be measured. Is not limited.

FIG. 20 shows changes in the wear of the conductive resin layer 15c in the measurement region and the difference between the maximum value and the minimum value of the reflected light amount per unit time when the developing device having the above-described structure is used.

As shown in FIG. 20, in the regular use method in which toner is replenished in accordance with the toner-out warning every about 3,000 sheets, the conductive resin layer 15c is worn from about 8,500 sheets before the third toner replenishment. As a result, the difference in the amount of reflected light started to increase, and at the time of about 9,500 sheets, the surface conductive resin layer 15c was almost worn.

In the present embodiment, the photodetection layer is made to maximize the difference in the amount of reflected light by abrasion of the conductive resin layer 15c at a time about 3,000 prints (one toner replenishment) earlier than the time when the image quality starts to deteriorate. The thickness of 15b was set. With this setting, as shown in the third embodiment, the user can know that the life of the developing device is "at most one toner replenishment".

It is desirable to directly measure the degree of wear of the conductive resin layer in the image area, but in the measurement of the amount of reflected light, the partial configuration, the material and the setting position of the detection device which have different amounts of reflected light are often limited. For example, if an insulating photodetection layer similar to that of the present embodiment is provided, when the surface conductive resin layer is worn away, conduction failure occurs and only that portion of the image becomes defective. It could not be detected.

The purpose of this embodiment is to provide the measurement region outside the image region and increase the degree of freedom in setting the detection time by changing the material and layer thickness of the photodetection layer.

As a matter of course, the developing device having the developing sleeve 15 according to the present embodiment is made into a process unit so that it can be easily attached and detached, and the developing device, the photosensitive drum, the charging device, the cleaning device, etc. are provided for easy maintenance. The process cartridges may be collectively used.

<Sixth Embodiment> Next, a sixth embodiment of the present invention will be described with reference to FIGS. 21 and 22 are longitudinal sectional views of the developing sleeve according to the present embodiment.
FIG. 23 is a block diagram showing the configuration of the control device including the wear degree detecting means and the wear warning means.

The developing sleeve 16 which is the developer carrying member according to the present embodiment has a sleeve base material 16a, an insulating layer 16b provided thereon, and a conductive resin layer 16c provided thereon. It is composed of layers.

The insulating layer 16b is applied to the outside of the image area, and is applied so as to straddle a sliding portion and a non-sliding portion with the blade near the image area. In this embodiment, the sleeve base material 16a and the conductive resin layer 16c are the same as those used in the first embodiment, and the insulating layer 16b is formed by applying a phenol resin and then thermally curing it. The insulating layer 16b was applied so as to have a thickness of about 6 μm. Conductive resin layer 16
The thickness of c is about 8 μm on the insulating layer 16b, and about 10 μm in other cases, and there is a slight step on the surface. In this embodiment,
A non-rubbing portion with the blade having the insulating layer 16b is a measurement region, and a conductive brush having a low stiffness is provided as a sliding contact 17 in this measurement region.

The wear degree detection circuit 19 shown in FIG. 23 is composed of the sliding contact 17 and a continuity detection circuit for measuring the DC component of the electric potential or current, and the control circuit 9 also serving as the wear degree warning means and the display device. The user is notified through 10 that the developing sleeve wear warning or the time for replacing the developing device has come.

Details of detection of the degree of wear of the conductive resin layer 16c will be described below.

In the present embodiment, the conduction detecting circuit measures the DC component of the current flowing from the conductive resin layer 16c of the non-rubbing portion through the sliding contact 17 during the application of the developing bias. The conductive resin layer 16c of the developing sleeve 16 becomes thinner mainly due to wear of the blade, but in the developing sleeve 16 according to the present embodiment, the conductive resin layer 16c of the rubbing portion with the blade is worn away, and FIG. As shown in, the insulating layer 16b is gradually exposed.

When the conductive resin layer 16c of the rubbing portion wears out over the entire circumference of the sleeve, the conductive resin layer 16 of the non-rubbing portion is formed.
c is electrostatically insulated from other parts. By adjusting the film thickness of the conductive resin layer 16c of the rubbing portion and the insulating layer 16b, the time when the conductive resin layer 16c of the non-rubbing portion is insulated can be adjusted.

Therefore, the wear degree of the conductive resin layer 16c can be detected more clearly by detecting the change in the potential of the sliding contact 17 or the DC component of the current. When the abrasion degree detection circuit determines that the conductive resin layer 16c of the non-rubbing portion is insulated, a signal is sent to the control circuit 9, and the control circuit 9 indicates to the display device 10 that "the developing sleeve is worn. , "At most one toner replenishment life"
Or the like, or an instruction such as "replace the developing device" or a display meaning that is output.

In the continuity detection as in the present embodiment, the structure of the detecting portion is very simple (the sliding contact 17 is not particularly required and a complicated structure is not required). Further, there is an advantage that the degree of wear of the developing sleeve 16 can be detected at any time (for example, during printing) while the developing bias is being applied.

As a matter of course, the developing device having the developing sleeve 16 according to the present embodiment is made into a process unit so that it can be easily attached and detached, and the developing device and the photosensitive drum, the charging device, the cleaning device, etc. are provided for easy maintenance. The process cartridges may be collectively used.

[0126]

As is apparent from the above description, claim 1
According to the invention described above, since a specific measurement region in which the degree of wear of the conductive resin of the developer carrying member is easily detected is provided, it is possible to more accurately estimate the wear state of the developer carrying member, and to replenish the toner. It is possible to notify the user of the replacement time of the developing device and the developing device more accurately.

According to the second aspect of the present invention, since the wear degree measuring region is provided in the non-image portion, the image is not affected by the measuring region, and the layer thickness of the conductive resin layer in the measuring region is not affected. By freely setting, it is possible to easily control the time when the warning is issued.

According to the third aspect of the invention, it is possible to utilize the fact that the amount of reflected light largely changes due to the abrasion of the conductive resin layer, and the amount of reflected light can be detected more easily and accurately.

According to the invention described in claim 4, by detecting the change of the DC component of the potential or the current of the detecting portion, the wear degree of the conductive resin layer can be detected more accurately and the measurement can be performed. By adjusting the thicknesses of the conductive resin layer and the insulating layer in the region, it is possible to easily control the timing of issuing the warning.

According to the fifth aspect of the present invention, it is possible to obtain the developing device capable of detecting the worn state of the developer carrying member.

According to the sixth aspect of the present invention, by providing the wear degree measuring means and the wear warning means, it is detected that the wear degree of the developer carrier exceeds a predetermined value, and the developer is supplied to the user. It is possible to prompt the user to notify the time of replacement of the developing device.

According to the invention described in claim 7, the wear or abrasion of the conductive resin layer is grasped as a change in the amount of reflected light, so that the non-contact measurement of conductivity does not have any influence on the developer carrying body which is the object of measurement. It is possible to measure the degree of wear of the resin layer.

According to the eighth aspect of the present invention, the developer which obstructs the measurement when the wear degree of the developer carrier is measured as a change in the amount of reflected light is removed from the measurement position on the developer carrier, The wear degree of the carrier can be measured more accurately.

According to the ninth aspect of the present invention, the abrasion of the conductive resin layer can be accurately, easily and continuously detected by the conduction detection.

According to the tenth aspect of the present invention, it is possible to obtain a process unit capable of detecting the wear state of the developer carrying member and excellent in maintainability.

According to the eleventh aspect of the present invention, it is possible to obtain a process cartridge in which the wear state of the developer carrying member can be detected and which has excellent maintainability.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control device including a wear degree detecting means and a wear warning means according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a developing device and a reflected light amount detection device according to Embodiment 1 of the present invention.

FIG. 4 is a diagram showing a change (change with time) in the amount of reflected light with respect to the number of passed sheets in Embodiment 1 of the present invention.

FIG. 5 is a cross-sectional view of a developing sleeve according to a second exemplary embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a developing sleeve according to a second exemplary embodiment of the present invention.

FIG. 7 is a diagram showing a change (change with time) in the amount of reflected light with respect to the number of passed sheets in Embodiment 2 of the present invention.

FIG. 8 is a transverse sectional view of a developing sleeve according to a third embodiment of the present invention.

FIG. 9 is a transverse sectional view of a developing sleeve according to a third embodiment of the present invention.

FIG. 10 is a diagram showing a change (change with time) in the amount of reflected light with respect to the number of passed sheets in Embodiment 3 of the present invention.

FIG. 11 is a longitudinal sectional view of a developing sleeve according to a fourth exemplary embodiment of the present invention.

FIG. 12 is a perspective view showing a reflected light amount detection device according to a fourth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a control device including wear degree detection means and wear warning means according to a fourth embodiment of the present invention.

FIG. 14 is a diagram showing a change (change with time) in the amount of reflected light with respect to the number of passed sheets in Embodiment 4 of the present invention.

FIG. 15 is a diagram showing a change (change with time) in the reflected light amount difference with respect to the number of passed sheets in Embodiment 4 of the present invention.

FIG. 16 is a longitudinal sectional view of a developing sleeve according to a fifth embodiment of the present invention.

FIG. 17 is a cross-sectional view of a developing sleeve according to the fifth exemplary embodiment of the present invention.

FIG. 18 is a diagram showing a change over time in the amount of reflected light in Example 5 of the present invention.

FIG. 19 is a diagram showing a change over time in the amount of reflected light in Example 5 of the present invention.

FIG. 20 is a diagram showing a change with time of a reflected light amount difference in Example 5 of the present invention.

FIG. 21 is a longitudinal sectional view of a developing sleeve according to Embodiment 6 of the present invention.

FIG. 22 is a longitudinal sectional view of a developing sleeve according to Embodiment 6 of the present invention.

FIG. 23 is a block diagram showing the configuration of a control device including wear degree detection means and wear warning means according to Embodiment 6 of the present invention.

FIG. 24 is a sectional view of a conventional image forming apparatus.

FIG. 25 is a sectional view of a conventional developing device.

[Explanation of symbols]

1,11,13,14,15,16 developing sleeve (developer carrier) 4 developing device 8,18 wear degree detecting device 8a light emitting element 8b light receiving element 8c, 19 wear degree detecting circuit 9 control circuit 10 display device 111 photosensitive Drum 118 process cartridge

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location G03G 21/00 510 (72) Inventor Junichi Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Koichi Suwa 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. (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. Inside the company

Claims (11)

[Claims] 1. A developer carrying member having a conductive resin layer, characterized in that an abrasion degree measuring region having a light reflectance and an electric conductivity different from those of the conductive resin layer is provided under the conductive resin layer. A developer carrying member. 2. The developer carrying member according to claim 1, wherein the wear degree measuring region is provided in a non-image portion. 3. The developer carrying member according to claim 1, wherein a layer having a light reflectance different from that of the conductive resin layer is provided below the conductive resin layer in the wear degree measurement region. 4. An insulating layer is provided below the conductive resin layer in the wear degree measurement region provided in the non-image portion, and the conductive resin layer is worn away to electrically insulate from the conductive resin layer in the image portion. 3. The developer carrying member according to claim 2, further comprising a detection unit that is provided. 5. The developer carried on a developer carrying body having a conductive resin layer is regulated by a developer regulating member to form a thin layer of the developer on the developer carrying body, and to the developing area. In the developing device for transporting, the developing device is provided with an abrasion degree measuring region below the conductive resin layer of the developer carrying member, the abrasion coefficient and the light reflectance and electric conductivity of which are different from those of the conductive resin layer. 6. An image forming apparatus provided with a developer carrying member having a conductive resin layer, characterized in that a wear degree measuring means for the conductive resin layer and a wear warning means are provided. 7. The image forming apparatus according to claim 6, wherein the wear degree measuring unit is a reflected light amount detecting unit. 8. The control means for developing the developer in the measurement area on the developer carrying member onto the latent image carrying member in order to detect the amount of reflected light from the developer carrying member. 7. The image forming apparatus according to item 7. 9. The image forming apparatus according to claim 6, wherein the wear degree measuring unit is a conductivity detecting unit. 10. A developer image carrier comprising a conductive resin layer, and an abrasion degree measuring region having a light reflectance and an electric conductivity different from that of the conductive resin layer under the conductive resin layer. A process unit including a developing device that is detachable from the main body of the image forming apparatus. 11. A developer image carrier comprising a conductive resin layer, and an abrasion degree measuring region having a light reflectance and an electric conductivity different from that of the conductive resin layer under the conductive resin layer. A process cartridge, which is configured to include a developing device and is detachable from the main body of the image forming apparatus.