JP2001066883A - Developer restricting member, developing device, process cartridge, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make stably obtainable a high quality image by preventing leaking of developer to a developer carrier edge surface from the periphery surface of the developer carrier while enabling size of a device to be made smaller and decreasing an image failure such as fogging, etc., of the edge part. SOLUTION: In this device, among abutted parts of an elastic blade 11 formed by material with a specified electrifying ability so that toner on the developing sleeve 10 at the time of toner quantity restriction is imparted with a specified charge, electrifying ability of the edge part of the material forming an abutted part of the edge part of the elastic blade 11 in a range in an axial direction of a developing sleeve 10 where an edge part leaking preventing member 21 is abutted to the developing sleeve 10 is lower than above mentioned specified electrifying ability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a developer regulating member, a developing device, a process cartridge, and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, such an image forming apparatus can be roughly divided into electrophotographic processes, and is composed of process equipment such as a charging device, a latent image carrier, an exposure device, a developing device, a transfer device, a cleaning device, and a fixing device. Have been.

[0003] Such an image forming apparatus comprises, among the above process equipment, a charging roller serving as a charging device, a photosensitive drum serving as a latent image carrier, a developing device, a cleaning device, and the like. As a detachable process cartridge, quick and simple maintenance is performed.

The charging roller provided in such an image forming apparatus has a structure in which a sponge layer is provided on a metal shaft as a shaft, and a sponge layer is further coated thereon.

[0005] The charging roller is brought into contact with the photosensitive drum by pressing both ends of the metal shaft toward the photosensitive drum, and is driven to rotate in a predetermined direction with respect to the photosensitive drum.

[0006] The charging roller is connected to a charging bias power supply for applying a DC voltage and an AC voltage, so that the surface of the photosensitive drum can be charged to a predetermined potential.

A photosensitive drum provided in such an image forming apparatus rotates in a predetermined direction, and its surface is charged by the charging roller. Then, the photosensitive drum is irradiated with a laser beam based on image information by an exposing device. An electrostatic latent image is formed. Note that the resolution of the image is determined by this exposure device.

A developing device provided in such an image forming apparatus is a developer container for storing a toner as a developer for visualizing an electrostatic latent image on a photosensitive drum, and a developer carrier for carrying the toner. The image forming apparatus includes a developing sleeve and a toner layer thickness regulating member which is a developer regulating member for regulating the toner on the developing sleeve to a predetermined toner layer thickness (toner amount) and applying a predetermined charge to the toner.

The developing sleeve is provided with a predetermined gap from the photosensitive drum, rotates in a predetermined direction, and is formed on the photosensitive drum by applying a bias obtained by superimposing an AC voltage on a DC voltage from a developing bias power supply. The formed electrostatic latent image is visualized as a toner image.

The transfer roller provided in such an image forming apparatus is configured by providing a sponge layer on a metal shaft as a shaft.

The transfer roller is connected to a transfer bias power supply and provided so as to be in contact with the photosensitive drum, whereby the visible image on the photosensitive drum formed as described above is transferred to a transfer material as a recording medium. It is supposed to be.

After the completion of the transfer step, the toner that has not been transferred remains on the photosensitive drum.

The remaining toner is scraped off from the photosensitive drum by a cleaning blade provided in a cleaning device, and is collected in a cleaning container.

The fixing device provided in such an image forming apparatus presses and heats the unfixed image formed on the transfer material to melt the toner on the transfer material, so that the unfixed image is semi-permanent on the transfer material. This is to form an output image that can be stored temporarily.

Through the above steps, a series of image formation is completed.

In such an image forming apparatus, it is common to use a powder having a very small average particle diameter of 10 μm or less as a toner, but it is very undesirable for a user to touch the toner. Therefore, in such an image forming apparatus, many measures have been taken so far to prevent the toner from leaking out of the image forming apparatus. An example will be described.

Both ends of the developing sleeve in the axial direction (longitudinal direction) are brought into contact with end seals made of an elastic material such as malt plane or felt.

Thus, since the end seal and the developing sleeve can be contacted without any gap, it is possible to prevent the toner coated on the developing sleeve from leaking out of the developing device. On the other hand, a gap is formed between the elastic blade and the frame of the developer container.

This is because if the end of the elastic blade interferes with the developer container frame, the coating on the end of the developing sleeve becomes unstable, so that there is a possibility that an image defect will occur corresponding to that portion. This is because in order to avoid the above and to form an image stably, it is inevitable that a gap is formed between the elastic blade and the developer container frame.

Therefore, in order to prevent leakage of the toner from the gap (hereinafter, referred to as toner leakage), it is necessary to provide a new seal member (hereinafter, referred to as an end leakage prevention member).

The end leakage preventing member is made of an elastic material such as a malt plane, and is disposed so as to contact the elastic blade, the developing sleeve, and the developer container frame.

This makes it possible to reliably prevent toner from leaking from the developing device.

[0023]

However, in such an image forming apparatus, the following problems may occur as the size of the image forming apparatus is reduced.

That is, if the longitudinal dimension of the developing device is shortened to the utmost in order to reduce the size of the device, fogging may occur at a portion outside the printing area of the transfer material (that is, at both ends of the transfer material).

The mechanism will be described with reference to FIG. FIG. 10 shows the distribution of the contact pressure of the elastic blade in the longitudinal direction of the developing sleeve.

The longitudinal position of the developing sleeve is based on the left end of the elastic blade (0 mm).

The method of measuring the contact pressure is such that a thin SUS plate (thickness: 50 μm) is sandwiched in the contact area between the elastic blade and the developing sleeve as shown in FIG. The force is measured with a spring balance and the reading is expressed as the abutment pressure.

In order to prevent toner leakage, it is necessary that the end leakage preventing member hold down the elastic blade.

Therefore, as shown in FIG. 10, the toner held on both ends of the developing sleeve is regulated by the elastic blade at a higher pressure than the other parts.

As a result, the surface layer of the developing sleeve corresponding to the end leakage preventing member is not coated with sufficient toner, so that the end leakage preventing member cannot be allowed to enter the printing area.

Therefore, it is the limit of miniaturization that the end leakage preventing member is adjacent to the printing area. At this time, the end leakage prevention member portion is brought into contact with the peripheral surface of the developing sleeve corresponding to the non-printing area of the transfer material, but the toner on the development sleeve corresponding to the position of the end leakage prevention member is removed from other portions. It has a higher tribo (charge per unit mass) because it is regulated by a higher contact pressure than

Therefore, since the toner at both ends of the developing sleeve has a high developing property, the toner becomes regular fogging especially in a low humidity environment, and stains both ends of the transfer material (hereinafter, referred to as "the toner").
Edge fog). This end fogging can be improved by lowering the contact pressure of the end leak prevention member against the developing sleeve, but in this case, the toner leaks from the gap between the elastic blade and the developer container frame, and the end fogging occurs. The original purpose of the part leakage prevention member cannot be fulfilled.

Further, if the end leakage preventing member is provided to the outside so as not to overlap with the transfer material, end fogging does not occur naturally, but this is contrary to the downsizing of the apparatus.

As described above, the contact pressure of the elastic blade against the developing sleeve, which is necessary to prevent toner leakage, and the contact pressure of the elastic blade against the developing sleeve, which can stably exhibit image performance, often do not match. is there.

Further, in order to achieve high image quality, the particle size of the toner has been reduced. However, when the size of the toner is reduced, the above-described edge fogging easily occurs, and further, the toner easily leaks. Therefore, when a small particle size toner is used, it becomes more difficult to achieve both end fogging and prevention of toner leakage.

Accordingly, the present invention prevents the developer from leaking from the peripheral surface of the developer carrying member to the end surface of the developer carrying member and reduces a defective image such as an end fog while realizing the miniaturization of the apparatus. Another object of the present invention is to provide a developer regulating member, a developing device, a process cartridge, or an image forming apparatus capable of stably obtaining a high-quality image.

[0037]

According to the present invention, the object is to provide a developer container for storing a developer and a developer container disposed opposite to a latent image carrier for carrying a latent image. A developer carrier rotatable around an axis that carries the developer, and a contact portion that abuts on a peripheral surface of the developer carrier and a line extending in the axial direction of the developer carrier. A developer regulating member for regulating the amount of the developer on the developer carrying member to a predetermined amount; and a developer regulating member disposed at both ends of the developer regulating member in the axial direction from a peripheral surface of the developer carrying member to an end surface of the developer carrying member. And a seal member that abuts and seals on the peripheral surface of the developer carrier so as to prevent the developer from leaking out of the developer container. When charging the developer, the developer on the developer carrier should be charged to a predetermined charge. In the developer regulating member formed of a material having a charging ability, of the contact portions of the developer regulating member, the end portion of the developer regulating member in the axial range where the seal member contacts the developer carrier. This is achieved by the first invention in which the end portion charging ability of the material forming the contact portion is lower than the predetermined charging ability.

Further, according to the present application, the object is to provide a developer container for storing a developer, and a developer provided opposite to a latent image carrier for carrying a latent image and supplied from the developer container. A developer carrying member rotatable around an axis carrying the developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member. A developer regulating member for regulating the amount of developer on the body to a predetermined amount, and a developer leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier provided at both ends of the developer regulating member in the axial direction. A developer regulating member for a developing device comprising a developer carrier peripheral surface and a sealing member that abuts and seals the developer container to prevent the developer regulating member, wherein the developer regulating member has one end fixed, A sheet forming a contact portion between the one end and the other end forming a free end Wherein the distance from the abutting portion of the developer regulating member to the other end is a predetermined distance, and the development is performed in the axial range where the seal member abuts the developer carrier. The invention is also achieved by the second invention in which the distance from the end contact portion to the free end of the agent regulating member is larger than the predetermined distance.

Further, according to the present application, the object is to provide a developer container for storing a developer, and a developer provided opposite to a latent image carrier for carrying a latent image and supplied from the developer container. A developer carrying member rotatable around an axis carrying the developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member. A developer regulating member for regulating the amount of developer on the body to a predetermined amount, and a developer leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier provided at both ends of the developer regulating member in the axial direction. A developing device comprising: a sealing member that abuts and seals the peripheral surface of the developer carrier and the developer container so as to prevent
The developer regulating member is formed of a material having a predetermined charging ability so as to charge the developer on the developer carrier to a predetermined charge when the developer amount is regulated. It is said that the end charging capability of the material forming the end contact portion of the developer regulating member in the axial range where the seal member contacts the developer carrier is lower than the predetermined charging capability. This is also achieved by the third invention.

Further, according to the present application, the above object is achieved in the fourth aspect of the present invention in the third aspect, in which the developer carrier is applied with an alternating electric field as a developing bias between the developer carrier and the latent image carrier. Is also achieved by

Further, according to the present application, the object is to provide a developer container for storing a developer, and a developer provided opposite to a latent image carrier for carrying a latent image and supplied from the developer container. A developer carrying member rotatable around an axis carrying the developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member. A developer regulating member for regulating the amount of developer on the body to a predetermined amount, and a developer leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier provided at both ends of the developer regulating member in the axial direction. A developing device comprising: a sealing member that abuts and seals the peripheral surface of the developer carrier and the developer container so as to prevent
The developer regulating member is a sheet-shaped member having one end fixed and forming a contact portion between the one end and the other end forming a free end. In the developing device in which the distance to the other end is a predetermined distance, the distance between the end contact portion of the developer regulating member and the free end of the developer regulating member in the axial direction range in which the seal member abuts on the developer carrier. This is also achieved by the fifth invention in which the distance is larger than the predetermined distance.

Further, according to the present application, the above object is achieved in the fifth aspect of the present invention in the fifth aspect, wherein the developer carrier is provided with an alternating electric field applied between the developer carrier and the latent image carrier as a developing bias. Is also achieved by

Further, according to the present application, the object is a process cartridge which holds at least a latent image carrier and a developing device and is detachable from an image forming apparatus main body.
The present invention is also achieved by a seventh invention including the developing device according to any one of the third invention to the sixth invention.

Further, according to the present application, the above object is an image forming apparatus for recording an image formed by a series of image forming processes on a recording medium, wherein the image forming apparatus is any one of the third to sixth aspects. The present invention is also achieved by an eighth invention in which the developing device of the present invention or the process cartridge of the seventh invention is provided.

That is, in the first invention according to the present application, excessive charging of the developer in the axial direction range of the developer carrier in which the seal member contacts the developer carrier is suppressed.

According to the second invention of the present application, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member is in contact with the developer carrier increases, and excessive charging is suppressed. I do.

Further, in the third invention according to the present application, excessive charging of the developer in the axial direction range of the developer carrier in which the seal member contacts the developer carrier is suppressed.

Further, according to the fourth aspect of the present invention, the developer layer thickness of the developer in the axial direction range of the developer carrier where the seal member contacts the developer carrier is increased, and excessive charging is suppressed. Then, the developer charged on the developer carrier is transferred onto the latent image carrier by an alternating electric field applied between the developer carrier and the latent image carrier.

Further, in the fifth invention according to the present application, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member is in contact with the developer carrier is increased, and excessive charging is suppressed. I do.

According to the sixth aspect of the present invention, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member is in contact with the developer carrier is increased to suppress excessive charging. Then, the developer charged on the developer carrier is transferred onto the latent image carrier by an alternating electric field applied between the developer carrier and the latent image carrier.

Further, in the seventh invention according to the present application, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member contacts the developer carrier is increased, and excessive charging is suppressed. At the same time, the process cartridge is attached and detached together with the latent image carrier and the developing device during maintenance or the like.

According to the eighth aspect of the present invention, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member is in contact with the developer carrier is increased, and excessive charging is suppressed. I do.

[0053]

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

(First Embodiment) First, an electrophotographic image forming apparatus 200 as an example of an image forming apparatus according to a first embodiment of the present invention will be described.

FIG. 1 is a schematic sectional view of such an image forming apparatus 200, and FIG. 2 is a schematic sectional view of a process cartridge 100 detachable from the image forming apparatus 200.

The image forming apparatus 200 is roughly classified into electrophotographic processes. The charging roller 1 as a charging device, the photosensitive drum 2 as a latent image carrier, the exposing device 7, the developing device 3,
It is composed of process devices such as a transfer roller 5 as a transfer device, a cleaning device 4, and a fixing device 6.

In the image forming apparatus 200, the charging roller 1, the photosensitive drum 2,
The developing device 3 and the cleaning device 4 are integrally and compactly incorporated as a process cartridge 100 to improve the speed and simplicity of maintenance.

The charging roller 1 has a structure in which a sponge layer is provided on a metal shaft as a shaft, and a resin layer is further coated thereon.

The charging roller 1 is brought into contact with the photosensitive drum 2 by pressing both ends of the metal shaft toward the photosensitive drum 2, and is driven to rotate in the direction of arrow a with respect to the photosensitive drum 2. .

The charging roller 1 is connected to a charging bias power supply (not shown) for applying a DC voltage and an AC voltage, whereby the surface of the photosensitive drum 2 can be charged to a predetermined potential. It has become.

The photosensitive drum 2 rotates in the direction of the arrow b in the figure, and its surface is charged by the charging roller 1. Then, the exposure device 7 irradiates the photosensitive drum 2 with a laser beam based on image information. An image is formed. The resolution of the image is determined by the exposure device 7.

The developing device 3 includes a developer container 9 containing a toner 8 serving as a developer for visualizing an electrostatic latent image on the photosensitive drum 2, and a developing sleeve 10 serving as a developer carrying member for carrying the toner 8. An elastic blade 11 serving as a developer regulating member that regulates the toner on the developing sleeve 10 to a predetermined toner layer thickness (toner amount) and imparts a predetermined charge to the toner. Is done.

The developing sleeve 10 is disposed with a predetermined gap from the photosensitive drum 2, rotates in the direction of arrow c in the figure, and applies a bias obtained by superimposing an AC voltage on a DC voltage from a developing bias power supply (not shown). Thereby, the electrostatic latent image formed on the photosensitive drum 2 is visualized.

The transfer roller 5 has a sponge layer provided on a metal shaft as a shaft.

The transfer roller 5 is connected to a transfer bias power supply (not shown), and is provided so as to be in contact with the photosensitive drum 2, whereby the visible image on the photosensitive drum 2 formed as described above is formed. The image is transferred onto a transfer material P as a recording medium.

After the completion of the transfer process, the toner 8 that has not been completely transferred remains on the photosensitive drum 2.

The remaining toner 8 is scraped off from the photosensitive drum 2 by the cleaning blade 12 provided in the cleaning device 4 and collected in the cleaning container 13.

The fixing device 6 can pressurize and heat the unfixed image formed on the transfer material P to melt the toner 8 on the transfer material P, so that the image can be semipermanently stored on the transfer material P. It forms an output image.

Through the above steps, a series of image formation is completed.

Next, the configuration of the developing device according to the present embodiment will be described with reference to FIGS.

FIG. 3 is a schematic view of the elastic blade 11 and the developing sleeve 10 viewed from the direction of the arrow E in FIG.
FIG. 4 is a sectional view taken along the line AA ′ of FIG. 3, and FIG. 5 is a sectional view taken along the line BB ′ of FIG.

The toner 8 in this embodiment is obtained by kneading 100 parts by weight of magnetite with a styrene-acrylic resin,
This is a negatively chargeable one-component dry toner whose average particle diameter is reduced to about 7 μm by pulverization.

The developing sleeve 10 is formed by roughening a φ16 aluminum tube by sandblasting, and then coating the surface of the surface with a coating of a mixture of phenolic resin and carbon and graphite, which are conductive fine particles.

In the above-mentioned coating, in order to control the toner to a desired charge amount and obtain a stable image quality, a compounding ratio of carbon + graphite: phenol = 1: 1 to 1: 3 is preferable.

The blast area and the coat area substantially coincide with each other, and include at least the entire area of the developing sleeve 10 which the elastic blade 11 as the toner regulating member contacts. Therefore, both ends of the developing sleeve 10 are in a state where the aluminum background is exposed.

In this embodiment, the length of the blast and coat regions in the longitudinal direction is 212 mm.

An elastic blade 1 made of urethane rubber or the like having a thickness of 1.0 mm and a length of 210 mm is provided on the toner regulating member.
Use 1.

The elastic blade 11 is adhered to one side of the supporting metal plate 16 and covers the blast and coat areas of the developing sleeve 10 over the entire length thereof.
It is in contact with 0.

The length of the elastic blade 11 needs to be equal to or larger than the maximum width of the image forming apparatus 200 that guarantees printing.

In the present embodiment, since the maximum sheet passing width is an A4 size image forming apparatus, the length of the elastic blade 11 is set to 210 mm as described above.

The developing sleeve 10 of the elastic blade 11
Is 20 gf at the center in the longitudinal direction.

The developing device 3 according to the present embodiment includes an end seal member 20 and an end leak prevention member 21 serving as a seal member in order to prevent toner from leaking.

The end seal 20 is adhered to the frame of the developer container 9 so as to surround and contact both ends of the developing sleeve 10 as shown in FIG. Teflon felt having a thickness of 2 mm is used for the end seal 20.

The end leakage preventing member 21 as a sealing member is made of a malt plane having a width of 5 mm, and is brought into contact with the elastic blade 11, the surface of the developing sleeve 10 and the frame of the developer container 9 as shown in FIG. As a result, toner leakage from the gap between the elastic blade 11 and the frame of the developer container 9 can be prevented.

At this time, as shown in FIG. 10, the distribution of the contact pressure of the elastic blade 11 against the developing sleeve 10 is such that the portion corresponding to the position of the end leakage preventing member 21 is about 30 gf.
And is higher than the other parts.

Here, the elastic blade 11 will be described in detail with reference to FIG.

The feature of the present embodiment is that, of the contact portions of the elastic blade 11, the material constituting the surface of the elastic blade 11 corresponding to the contact portion of the end leakage preventing member 21 has the ability to charge the toner, and other characteristics. This is to lower the charging ability of the material constituting the portion to the toner.

The elastic blade 11 according to the present embodiment
Most parts are made of urethane rubber. However,
Teflon particles having a negative charge polarity with respect to the toner are applied only on the developing sleeve contact surface 11a at a width of 5 mm from both ends in the longitudinal direction of the elastic blade 11, that is, on the portion corresponding to the end leakage preventing member 21. Distributed. Thus, the toner tribo of the contact portion of the end leak prevention member 21 having a high contact pressure can be suppressed to an appropriately low level. still,
The surface coverage of the Teflon particles is about 20% with respect to urethane rubber. This is because if more Teflon particles are dispersed than this, the toner tribo is excessively low, and there is a possibility that reversal fog may occur, which is not preferable. Also, instead of dispersing the Teflon particles, the elastic blades 11 corresponding to the end leakage preventing members 21 are not used.
A part of the contact surface of the developing sleeve 10 may be coated with Teflon resin.

Next, the effect of the present invention was verified with respect to the image forming apparatus 200 including the developing device 3 having the above configuration.
The results of the experiment will be described with reference to FIGS.

FIG. 7 shows that the whole white image was sampled in a low temperature and low humidity environment of 10 ° C. and 10% RH, and the fog was measured.
This shows the relationship between the longitudinal position of the developing sleeve and fog.

The measurement of fogging was carried out with a densitometer TC-6DS manufactured by Tokyo Denshoku Co., Ltd.

The fog R (%) is defined as R1 (%) when the measured value of the whole white image passed through the image forming apparatus is R1 (%), and R2 (%) is the measured value of the paper not passed through the image forming apparatus. , R =
Defined as R1-R2. The larger the R, the worse the fog.

FIG. 8 shows a developing sleeve 1 according to the present embodiment.
The relationship between the longitudinal position of 0 (position in the axial direction) and the tribo held by the toner coated on the developing sleeve 10 is shown.

In FIG. 8, the longitudinal position of the developing sleeve 10 is based on the left end of the elastic blade 11 in FIG.
m). The tribo is obtained by sucking the toner on the developing sleeve 10, measuring the amount of charge with an electrometer manufactured by Kesley, and dividing the amount of charge by the weight.

As a comparative example, a case where the elastic blade is made of only urethane and is uniform in the longitudinal direction as a conventional elastic blade is given. Other configurations are the same as in the present embodiment.

The bias condition of the image forming apparatus is such that a developing component is applied with a DC component of -450 V and 1.6 kVpp / 1.5.
A dark portion potential VD is set to -700 V, and a bright portion potential is set to -200 V using a superimposed rectangular wave of kHz.

The process speed is set to 60 mm / sec.
It is assumed that eight sheets of A4 size paper can be output per minute in the vertical direction.

As shown in FIG. 7, the experimental results show that the fogging at both ends of the image is as large as about 3% in the conventional embodiment, whereas the image area is about 1% at both the ends and the center in the present embodiment. A good image with little fog was obtained over the whole.

Further, as shown in FIG. 8, the toner tribo on the developing sleeve corresponding to the position of the end leakage preventing member is -10 μC / g even though the contact pressure of the elastic blade against the developing sleeve is high. In addition, the toner can be made smaller than the tribo of the toner on the developing sleeve corresponding to the position of the end leakage preventing member in the conventional embodiment, and is uniform over almost the entire longitudinal length of the developing sleeve.

This is because the charging ability of the material constituting the abutting surface of the elastic blade 11 corresponding to the abutting portion of the end leakage preventing member 21 with respect to the toner is determined. This is because the ability of the constituent materials to charge the toner is lower than that of the material, so that the ability to apply the charge to the toner is reduced.

Therefore, the contact portion of the end leakage preventing member 21 has a high contact pressure against the developing sleeve 10 while maintaining a high contact pressure.
As described above, excessive charging of the toner held at the end of the developing sleeve 10 can be prevented, the tribo can be suppressed as low as the central portion, and the tribo distribution of the toner in the longitudinal direction can be made substantially uniform.

Therefore, according to the present embodiment, both ends of the elastic blade 11 maintain the necessary contact pressure in order to prevent the toner from leaking, and the ends generated corresponding to the positions of the end leakage preventing members 21 are maintained. Part fogging can be reduced, and downsizing of the image forming apparatus can be realized at the same time.

The materials to be added to the elastic blade and the amount of the materials are not limited to these as long as the effects of the present invention are not impaired.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The description of the same configuration as that of the first embodiment is omitted.

FIG. 9 is a schematic view showing the configuration of the developer regulating member according to the present embodiment in the longitudinal direction.

In FIG. 9, the area where the elastic blade 11 'comes into contact with the developing sleeve 10 is denoted by D, and this area of contact D
The distance from the free end side of the elastic blade 11 'to the free end of the elastic blade 11' is represented by L. The longer L is,
Since the amount of the toner guided to D increases, the tribo can be reduced.

In this embodiment, if L corresponding to the contact portion of the end leakage preventing member 21 is L2 and L corresponding to the other portions is L1, L1 <L2. I have. In the present embodiment, L1 = 2 mm, L2 =
3 mm. The distribution of the contact pressure of the elastic blade 11 'in the longitudinal direction at this time is the same as that in FIG.

A similar verification experiment was performed by applying such a developing device to the same image forming apparatus as in the first embodiment.

As a result, a good image could be obtained without edge fogging as in the first embodiment.

This is because the free length of both ends of the elastic blade 11 ′ corresponding to the end leak preventing member 21 is made longer than the other portions, so that the amount of toner coating on the portion corresponding to the end leak preventing member 21 is increased. Is increased compared to other parts.

Therefore, the tribo of the toner held at the end of the developing sleeve 10 having a high contact pressure can be made lower than in the conventional embodiment, and can be made substantially uniform in the longitudinal direction. The end fog peculiar to the corresponding part can be reduced.

As described above, according to the present embodiment, both ends of the elastic blade 11 'maintain the necessary contact pressure in order to prevent the leakage of the toner, and the ends generated corresponding to the positions of the end leak preventing members 21. Part fogging can be reduced, and downsizing of the image forming apparatus can be realized at the same time.

[0113]

As described above, according to the first aspect of the present invention, excessive charging of the developer in the axial direction range of the developer carrier in which the seal member contacts the developer carrier is suppressed. As a result, uniformity of the developer on the developer carrier is achieved, and the size of the apparatus is reduced.
In addition to preventing the developer from leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier, defective images such as end fogging can be reduced, and a high-quality image can be stably obtained.

According to the second invention of the present application,
Since the thickness of the developer layer of the developer increases in the axial direction range of the developer carrier where the seal member contacts the developer carrier, excessive charging is suppressed, so that the developer on the developer carrier is uniform. In addition to preventing the developer from leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier while reducing the size of the apparatus, it is also possible to reduce defective images such as end fogging,
High quality images can be obtained stably.

Further, according to the third aspect of the present invention, the developer is prevented from being excessively charged in the axial direction range of the developer carrying member in which the seal member contacts the developer carrying material. In addition, the uniformity of the developer on the developer carrying member is achieved, and while miniaturizing the apparatus, the developer is prevented from leaking from the peripheral surface of the developer carrying member to the end surface of the developer carrying member. Defective images such as fog can be reduced, and high-quality images can be stably obtained.

According to the fourth invention of the present application,
The thickness of the developer layer of the developer in the axial direction range of the developer carrier where the seal member contacts the developer carrier is increased to suppress excessive charging, and the developer charged on the developer carrier becomes the developer. An alternating electric field applied between the carrier and the latent image carrier allows the developer to be transferred onto the latent image carrier, so that the developer on the developer carrier is uniformized, While realizing miniaturization, while preventing developer leakage from the peripheral surface of the developer carrier to the end surface of the developer carrier,
Defective images such as edge fog can be reduced, and high-quality images can be stably obtained.

Further, according to the fifth aspect of the present invention, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member is in contact with the developer carrier increases, and excessive charging is suppressed. As a result, the developer on the developer carrier is made uniform, and the size of the apparatus is reduced, while preventing the developer from leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier. In addition to this, a defective image such as edge fogging can be reduced, and a high-quality image can be stably obtained.

According to the sixth invention of the present application,
The thickness of the developer layer of the developer in the axial direction range of the developer carrier where the seal member contacts the developer carrier is increased to suppress excessive charging, and the developer charged on the developer carrier becomes the developer. An alternating electric field applied between the carrier and the latent image carrier allows the developer to be transferred onto the latent image carrier, so that the developer on the developer carrier is uniformized, While realizing miniaturization, while preventing developer leakage from the peripheral surface of the developer carrier to the end surface of the developer carrier,
Defective images such as edge fog can be reduced, and high-quality images can be stably obtained.

Further, according to the seventh aspect of the present invention, the developer layer thickness of the developer in the axial direction range of the developer carrier in which the seal member is in contact with the developer carrier increases, and excessive charging is suppressed. At the same time, since the process cartridge is attached and detached together with the latent image carrier and the developing device at the time of maintenance, etc., the developer on the developer carrier is made uniform, and the maintenance is speeded up and simplified. In addition to preventing the developer from leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier and reducing defective images such as fogging at the end, stable and high image quality can be achieved. Images can be obtained.

Further, according to the eighth invention of the present application,
Since the thickness of the developer layer of the developer in the axial direction range of the developer carrier in which the seal member contacts the developer carrier is increased to suppress excessive charging, the uniformity of the developer on the developer carrier is ensured. In addition to preventing the developer from leaking from the peripheral surface of the developer carrier to the end surface of the developer carrier while reducing the size of the apparatus, it is also possible to reduce defective images such as end fogging,
High quality images can be obtained stably.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a process cartridge provided in the image forming apparatus of FIG.

FIG. 3 is a schematic diagram illustrating a configuration in a longitudinal direction of a developing device provided in the process cartridge of FIG. 2;

FIG. 4 is a sectional view taken along line AA ′ in the developing device of FIG. 3;

FIG. 5 is a sectional view taken along line BB ′ of the developing device of FIG. 3;

FIG. 6 is a schematic view showing a configuration in a longitudinal direction of a developer regulating member according to the first embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the position in the longitudinal direction (axial direction) of the developer carrier according to the first embodiment of the present invention and the rate of occurrence of fog images.

FIG. 8 is a graph showing a relationship between a position in a longitudinal direction (axial direction) of the developer carrier and a tribo of the developer on the surface of the developer carrier according to the first embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a configuration in a longitudinal direction of a developing device according to a second embodiment of the present invention.

FIG. 10 is a graph showing a relationship between a position in a longitudinal direction (axial direction) of a developer carrying member and a contact pressure of a developer regulating member against the developer carrying member.

11 is a schematic diagram for explaining a method of measuring a contact pressure of a developer regulating member with respect to a developer carrying member in FIG.

[Explanation of symbols]

 Reference Signs List 2 photosensitive drum (latent image carrier) 3 developing device 8 toner (developer) 9 developer container 10 developing sleeve (developer carrier) 11 elastic blade (developer regulating member) 20 end seal 21 end leak prevention member (Seal member) 100 Process cartridge 200 Image forming apparatus P Transfer material (recording medium)

Continuing on the front page (72) Inventor Keiji Okano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Gaku Konishi 3-2-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoru Motohashi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H071 BA35 DA08 2H073 BA03 BA13 CA02 2H077 AD06 AD13 AD17 AD36 AE03 CA12

Claims (8)

[Claims] 1. A developer container for housing a developer, and a developing device disposed opposite to a latent image carrier for holding a latent image and rotatable about an axis for supporting the developer supplied from the developer container. A developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member, and the contact makes the amount of the developer on the developer carrying member a predetermined amount. A developer regulating member for regulating, and a peripheral surface of the developer carrying member disposed at both ends of the developer regulating member in the axial direction so as to prevent a developer from leaking from a peripheral surface of the developer carrying member to an end surface of the developer carrying member. And a seal member that abuts on and seals the developer container, for a developing device, wherein the developer restrictive member charges the developer on the developer carrier with a predetermined charge when regulating the amount of the developer. Developer made of a material having a predetermined charging ability so that it can be charged In the regulating member, among the contact portions of the developer regulating member, the end charging ability of the material forming the end contact portion of the developer regulating member in the axial direction range in which the seal member contacts the developer carrier is not limited. A developer regulating member having a lower charging ability than the predetermined charging ability. 2. A developer container for housing a developer, and a developing device disposed opposite to a latent image carrier for holding a latent image and rotatable about an axis for holding the developer supplied from the developer container. A developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member, and the contact makes the amount of the developer on the developer carrying member a predetermined amount. A developer regulating member for regulating, and a peripheral surface of the developer carrying member disposed at both ends of the developer regulating member in the axial direction so as to prevent a developer from leaking from a peripheral surface of the developer carrying member to an end surface of the developer carrying member. And a sealing member that abuts and seals on the developer container, the developer regulating member having one end fixed and the other end forming a free end with the one end. A sheet-shaped member that forms a contact portion between the toner control member and the developer regulating member. In the developer regulating member in which the distance from the contact portion to the other end portion is a predetermined distance, from the end contact portion of the developer regulating member in the axial range where the seal member contacts the developer carrier. A developer regulating member, wherein a distance to an end free end is larger than the predetermined distance. 3. A developer container for housing a developer, and a developing device arranged opposite to a latent image carrier for holding a latent image and rotatable about an axis for holding the developer supplied from the developer container. A developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member, and the contact makes the amount of the developer on the developer carrying member a predetermined amount. A developer regulating member for regulating, and a peripheral surface of the developer carrying member disposed at both ends of the developer regulating member in the axial direction so as to prevent a developer from leaking from a peripheral surface of the developer carrying member to an end surface of the developer carrying member. And a seal member that abuts and seals on the developer container, wherein the developer regulating member has a predetermined charging ability to charge the developer on the developer carrier to a predetermined charge when regulating the amount of the developer. In a developing device made of a material having Of the abutting portions of the members, the end charging ability of the material forming the end abutting portion of the developer regulating member in the axial range where the seal member abuts the developer carrier is lower than the predetermined charging ability. A developing device, comprising: 4. The developing device according to claim 3, wherein an alternating electric field is applied between the developer carrier and the latent image carrier as a developing bias. 5. A developer container for housing a developer, and a developing device disposed opposite to a latent image carrier for holding a latent image and rotatable around an axis for holding the developer supplied from the developer container. A developer carrying member, and a contact portion that abuts on a peripheral surface of the developer carrying member in a line area extending in the axial direction of the developer carrying member, and the contact makes the amount of the developer on the developer carrying member a predetermined amount. A developer regulating member for regulating, and a peripheral surface of the developer carrying member disposed at both ends of the developer regulating member in the axial direction so as to prevent a developer from leaking from a peripheral surface of the developer carrying member to an end surface of the developer carrying member. And a seal member that abuts and seals the developer container, wherein the developer regulating member has one end fixed and abuts between the one end and the other end that forms a free end. A sheet-like member that forms a portion between the contact portion of the developer regulating member and the other end. In the developing device in which the distance is a predetermined distance, the distance from the end contact portion to the free end of the developer regulating member in the axial direction range where the seal member contacts the developer carrier is A developing device, wherein the developing device is longer than a predetermined distance. 6. The developing device according to claim 5, wherein an alternating electric field is applied between the developer carrier and the latent image carrier as a developing bias. 7. A process cartridge holding at least a latent image carrier and a developing device and detachable from an image forming apparatus main body, wherein the developing device according to any one of claims 3 to 6 is provided. A process cartridge comprising: 8. An image forming apparatus for recording an image formed by a series of image forming processes on a recording medium,
An image forming apparatus comprising: the developing device according to claim 3; or the process cartridge according to claim 7.