JPH09197823A - Developing device, image forming device, and process cartridge - Google Patents

Abstract

(57) Abstract: The present invention is a developing device of a type that supplies a developer to a developing portion by the weight drop of the developer, and suppresses excessive charging of the developer, and makes it uniform in the longitudinal direction of the developing portion. It is an object of the present invention to provide a developing device capable of feeding a developer to the developing device and preventing the density of the developed image from being low at the end portion. SOLUTION: The inclination angle of the inner floor surface of the developer container 6 is
The length of the mounting portion of the developer carrying member 3 is 70 degrees (angle a in FIG. 1) from both ends of the container to, for example, 20 mm, and 55 degrees (angle b in FIG. 1) in other ranges.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device, an image forming apparatus and a process cartridge used in a copying machine, a page printer and the like.

[0002]

2. Description of the Related Art In a conventional electrophotographic image forming apparatus, a latent image formed on an image bearing member by charging / exposure is non-magnetic or magnetic by a developing device.
In addition, a one-component or two-component developer is attached to obtain a visible image, and then the visible image on the image carrier is transferred to a recording material such as paper, and then transferred. The image is formed by fixing the visible image transferred to the.

Therefore, in such an image forming apparatus, the developer is consumed each time an image is formed, so that the developing apparatus is provided with a developer container for accumulating the developer.

There are several types of developer containers, and when the developer filled in the developer container is used up, the life of the developer container ends, and in addition, a part of the developer container has a developer supply port. There are not a few that are equipped with a new developer supply from the outside.

Further, when the image carrier, the cleaning unit, the developing device, etc. are formed as a process cartridge in a detachable manner in the image forming apparatus and the remaining amount of the developer in the developer container becomes low, the entire process cartridge is There is a replacement that simplifies the work for replenishing the developer.

FIG. 10 shows an example of a developing device equipped with the developer container as described above. In general, a developing device is often configured such that a developer carrier 3 and a developer amount regulating member 4 are installed below a developer container 1 as shown in FIG. 10, and the developer carrier 3 is indicated by an arrow in the figure. By rotating in the direction, the developer 2 is carried on the peripheral surface, and the developer 2 is conveyed.

In such a developing device, the bottom of the developer container 1 is formed into an inclined shape having a uniform angle equal to or greater than the repose angle of the developer 2, so that the developer 2 is moved downwardly of the container due to the influence of gravity. Although it falls and is supplied to the developer carrying member 3,
In order to keep the image density uniform over the entire image forming width, it is necessary to send the developer 2 to the entire area in the longitudinal direction of the developing unit in which the developer carrying member 3 is arranged, in just the right amount.

[0008]

However, according to the above-mentioned conventional example, in the moving path of the developer 2 from the inside of the developer container 1 to the developing portion, the development passing through both longitudinal ends of the developer container 1 is performed. It has been confirmed by experiments by the present inventors that the agent 2 may have poorer fluidity than the developer 2 that passes through the central portion.

In the case of the developer container 1 as shown in FIG. 10,
The developer 2 is affected by gravity and falls to the vicinity of the developer carrying member 3. At this time, in the central portion in the longitudinal direction of the developer container 1, what blocks the fall of the developer 2 is powder. It is only the interaction that acts between certain developers 2. Therefore, the degree of freedom of the developer 2 is high and the developer 2 does not aggregate into a certain portion.

However, when the developer 2 passing near both ends in the longitudinal direction of the developer container 1 falls due to the influence of gravity, in addition to the acting force other than the above, the developer 2 and the developer container 1
Since it receives a frictional resistance force generated between the side wall and the side wall, it is less likely to drop than the developer 2 in the central portion of the developer container 1. For this reason, the developer 2 may stagnate in the vicinity of both ends of the developing section provided under the developer container 1.

The stagnant developer 2 further blocks the inflow of the developer 2 from above, and since the developer 2 agglomerates at this portion, the amount of the developer 2 sent to the end portion of the developing portion is the central portion. Less than the amount of developer 2 sent to
When the amount of is less than the amount required for development, the density may be low at both ends of the developed image.

The stagnation of the developer 2 tends to be particularly remarkable when the developer absorbs moisture in a high temperature and high humidity environment.

For such a stagnation of the developer, a method of uniformly increasing the inclination angle of the inner floor surface of the developer container 1 can be considered. However, the inclination of the inner floor surface of the developer container 1 can be considered. Considering the shape of the developer container 1 so that the same amount of the developer 2 can be filled by changing the angle, the larger the inclination angle of the floor surface, the larger the size of the developer container 1 in the height direction becomes. Will have to.

Further, when the height of the developer container 1 is increased so that the developer 2 is accumulated higher, the pressure due to the weight of the developer 2 loaded on the upper portion at the longitudinal center near the developing portion is increased. It is considered that the developer 2 is strongly pressed against the developer carrier 3, and due to violent friction at that time, the developer 2 has a charge (excessive charge) exceeding the appropriate charge amount.

Further, even in the vicinity of the developer carrying member, it is considered that the movement of the developer 2 is hindered by the above-mentioned pressure and the developer 2 which is rubbed at the same place for a long time is also excessively charged.

When the developer 2 is excessively charged, the quality of the output image is significantly impaired due to uneven density.

Therefore, the present invention is a developing device of the type that supplies the developer to the developing portion by the weight drop of the developer, and suppresses excessive charging of the developer so that the developer is evenly distributed in the longitudinal direction of the developing portion. It is an object of the present invention to provide a developing device capable of being sent in and preventing a low density at the end of a developed image.

Further, in an image forming apparatus having a developing unit arranged below the developer container unit and supplying the developer to the developing unit by dropping the developer by its own weight, excessive charging of the developer is prevented. The purpose is to prevent the density of the output image edge portion from being low due to insufficient inflow of the developer into the developing portion edge portion.

Further, in the process cartridge provided with a developing device arranged below the developer container part and supplying the developer to the developing part by dropping the developer by its own weight,
It is an object of the present invention to suppress the excessive charging of the developer and prevent the density of the output image edge portion from being low due to insufficient inflow of the developer into the developing portion edge portion.

[0020]

According to the first invention of the present application, the above object is to dispose a developing section provided with a developer carrying member under a developer container, and In the developing device, in which the inner floor surface of the developer container is inclined at a predetermined angle so that the inner side is higher than the front side, and the developer is supplied to the developing portion by its own weight drop, The inclination angle of the inner floor of the container is achieved by making both ends of the developer container in the longitudinal direction larger than the central part in the longitudinal direction of the developer container.

According to the second aspect of the present invention,
In the first aspect of the invention described above, the inner floor surface of both ends of the developer container having an inclination angle larger than that of the central portion in the longitudinal direction of the developer container is more likely to be developed than the central portion of the developer container in the longitudinal direction. This is achieved by providing a slope such that the side wall side of the agent container becomes higher.

Further, according to the third invention of the present application, the above-mentioned object is to develop a developing section provided with an image bearing member carrying a latent image and a developer bearing member facing the image bearing member. The developer container is disposed below the developer container, and the inner floor surface of the developer container is inclined at a predetermined angle so that the back side of the developer container is higher than the front side of the developer carrier. In the image forming apparatus having a developing device for supplying the developer to the inner surface of the developer container, the inclination angle of the inner floor surface of the developer container is larger at both ends of the developer container in the longitudinal direction than at the central part in the longitudinal direction of the developer container. It is achieved by increasing.

According to a fourth aspect of the present invention,
In the third aspect of the invention described above, the inner floor surface of both ends of the developer container having an inclination angle larger than that of the central portion of the developer container in the longitudinal direction is more developed than the central portion of the developer container in the longitudinal direction. This is achieved by providing a slope such that the side wall side of the agent container becomes higher.

Further, according to the fifth invention of the present application, the above-mentioned object is to develop a developing section provided with an image bearing member carrying a latent image and a developer bearing member facing the image bearing member. The developer container is disposed below the developer container, and the inner floor surface of the developer container is inclined at a predetermined angle so that the back side of the developer container is higher than the front side of the developer carrier. In a process cartridge that has a developing device that supplies a developer to the
The inclination angle of the inner floor surface of the developer container is achieved by making the both ends of the developer container in the longitudinal direction larger than the central part in the longitudinal direction of the developer container.

According to the sixth aspect of the present invention,
In the fifth aspect of the invention described above, the inner floor surface of both ends of the developer container having an inclination angle larger than that of the central portion in the longitudinal direction of the developer container is more likely to be developed than the central portion of the developer container in the longitudinal direction. This is achieved by providing a slope such that the side wall side of the agent container becomes higher.

That is, according to the first aspect of the present application, the developer at both ends of the developer container is separated from the side wall of the developer container while keeping the inner floor inclination angle of the central part of the developer container as small as possible. The internal floor surface inclination angle at both ends of the developer container was increased so that the frictional resistance of the developer could be easily shaken off and dropped. Does not cause thinness. On the other hand, since the internal floor surface inclination angle of the central portion of the developer container is the same as that of the conventional one, the developer is not strongly rubbed against the developer carrier due to the pressure of the developer loaded on the upper side. Prevents excessive charging of the developer.

In the second invention according to the present application, the center of the developer container in the longitudinal direction is formed on the inner floor of both ends of the developer container whose inclination angle is larger than the center of the developer container in the longitudinal direction. Since the side wall of the developer container is inclined higher than the side of the developer container, the flowability of the developer from the both ends of the developer container to the developing section is further improved, and the developer is not transferred to both ends of the developing section. The shortage of the supply of the agent is eliminated, and the low density of the developed image edge portion does not occur.

Further, in the third invention according to the present application, both ends of the developer container are kept with the inner floor surface inclination angle of the central part of the developer container of the developing device provided in the image forming apparatus kept as small as possible. The internal floor inclination angle at both ends of the developer container is increased so that the developer on the other side of the developer container easily shakes off the frictional resistance with the side wall of the developer container and falls easily. The developer is made to flow into the entire area in the hand direction without excess or deficiency, and the low density of the end portion of the output image does not occur. On the other hand, since the internal floor surface inclination angle of the central portion of the developer container is the same as that of the conventional one, the developer is not strongly rubbed against the developer carrier due to the pressure of the developer loaded on the upper side. Prevents excessive charging of the developer.

Further, in the fourth invention according to the present application, the center of the developer container in the longitudinal direction is formed on the inner floor of both ends of the developer container whose inclination angle is larger than the center of the developer container in the longitudinal direction. Since the side wall of the developer container is inclined so that it is higher than the side of the developer container, the flowability of the developer from both ends of the developer container to the developing section is further improved, and the developing section is developed in the entire longitudinal direction. Since the agent is made to flow in without excess or deficiency, the thin density of the output image edge does not occur.

Further, according to the fifth aspect of the present application, the developer on both ends of the developer container is filled with the developer while keeping the inner floor inclination angle of the center part of the developer container of the process cartridge as small as possible. Since the internal floor surface inclination angle at both ends of the developer container is increased so as to easily shake off the frictional resistance with the container side wall and drop, the developer is provided in the entire longitudinal direction of the developing unit provided below the developer container unit. In the image forming apparatus equipped with the process cartridge, the density of the end portion of the output image does not decrease due to insufficient supply of the developer. On the other hand, the inclination angle of the inner floor surface of the central portion of the developer container is the same as the conventional one, so that the developer is not strongly rubbed against the developer carrier due to the pressure of the developer loaded above, which is caused by this. Prevents excessive charging of the developer.

In the sixth invention according to the present application, the inner peripheral surface of the developer container at both end portions whose inclination angle is larger than the central portion in the longitudinal direction of the developer container has the central portion in the longitudinal direction of the developer container. Since the side wall of the developer container is inclined so that it is higher than the side of the developer container, the flowability of the developer from both ends of the developer container to the developing section is further improved, and the developing section is developed in the entire longitudinal direction. Inject the agent just enough. Therefore, in the image forming apparatus equipped with this process cartridge, the density of the output image end portion is not reduced due to insufficient supply of the developer.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a developing device according to a first embodiment of the present invention. 2 is an internal view of the developer container 6 used in the developing device of the first embodiment.

As shown in FIG. 1, an opening is provided at the lower end of the developer container 6, a developer carrying member 3 is rotatably disposed in the opening, and one end of the developer container is further provided. A development amount regulating member 4 is provided which is attached to the outer wall of No. 1 and whose free end is elastically brought into contact with the developer carrying member 3.

The developer 2 contained in the developer container 1 drops and moves by its own weight to the vicinity of the opening at the lower end of the developer container 6, and the developer 2 near the opening of the developer container 6
1 is uniformly adjusted in amount by the developer carrying member 3 and the developer amount regulating member 4 which rotate in the direction of the arrow in FIG. 1, and is conveyed to the developing unit while being charged.

When an image carrier (not shown) on which an electrostatic latent image is formed is placed opposite to this developing section, the developer 2 which has flown from the developing device by utilizing the action force of the electric field carries the image. Development is carried out by adhering to the latent image on the body.

In this embodiment, the average particle size is 8 to 12 μm.
A developer having a repose angle of 50 degrees (by the Coulter counter method) is used, and the inclination angle of the inner floor surface of the developer container 6 is set from the both ends of the container with respect to the length of the mounting portion of the developer carrier 3. 70 degrees up to 20 mm (Fig. 1
Medium angle a), 55 degrees in other ranges (angle b in Fig. 1)
And

Using the developing device of this embodiment as described above, the developer carrying member 3 is rotated at a speed of 50 revolutions per minute to obtain 15 ° C., 15% (low temperature and low humidity) and 30 ° C., 80%.
When continuous development of the solid black latent image on the image bearing member was carried out in each atmosphere of (high temperature and high humidity), the edge density was low at all points from the start of durability to the end of the developer in any atmosphere. It was possible to obtain a developed image without density unevenness.

Further, in order to confirm that the developing device of the present embodiment is not overcharged, 15 ° C., 15%
In the atmosphere of (low temperature and low humidity), the developing device of the present embodiment and the developing device in which the inclination angle of the floor surface of the developer container is 70 degrees are used, and the developer carried on each developer carrier is used. The comparison of the amount of electric charge of each was carried out. The blow-off method was used to measure the charge amount.

As a result, in the developing device of this embodiment, the electric charge of the developer was stable at 8 to 10 μC / g, regardless of the position in the longitudinal direction of the developer carrying member.

However, in the developing device in which the floor surface inclination angle of the entire developer container is 70 degrees, the developer carried on both ends of the developer carrying member maintains 8 to 10 μC / g. , The developer carried in the central portion is 12 to 15 μC /
had obtained a charge of g.

From the above, it is possible to eliminate the insufficient supply of the developer to both ends of the developing portion while preventing the developer from being excessively charged. It can be seen that a developed image without unevenness was obtained.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 3 is a diagram showing an image forming apparatus according to the second embodiment of the present invention. In the present embodiment, the inclination angle of the floor surface of the developer container 6 is set within a range of 25 mm from both ends of the container with respect to the length of the mounting portion of the developer carrier 3.
5 ° C (angle c in Fig. 3), 50 degrees in other ranges (Fig. 3
The middle angle d) was set. The developer 2 used was the same as the developer used in the first embodiment.

In the apparatus shown in FIG. 3, the developer 2 in the developer container 6 is the developer carrier 3 and the developer amount regulating member 4.
As a result, the amount is uniformly adjusted, and while being charged, it is conveyed to the surface of the drum-shaped photoreceptor 7 as an image carrier. On the other hand, the drum-shaped photosensitive member 7 is rotated by the power source (not shown) while rotating at a speed of 40 rpm in the direction of the arrow in FIG.
A bias voltage in which a DC voltage of -700 V and an AC voltage composed of a sine wave of 400 Hz with a peak-to-peak voltage of 2000 V are superimposed is applied through the charging roller 8, and the surface thereof is approximately -7.
It is charged to 00V. A latent image is drawn on the drum-shaped photoconductor 7 by the irradiation light from the laser irradiation device 9.

A bias voltage in which a DC voltage of -500 V and an AC voltage of a sine wave of 1800 Hz with a peak-to-peak voltage of 1600 V are superimposed is applied to the developer carrying member 3, whereby the developer 2 is drum-shaped. The photoreceptor 7 and the developer carrier 3 are reciprocated. At this time, the actual potential on the drum-shaped photoconductor 7 is a negative potential in both the bright portion and the dark portion of the latent image, and the developer 2 corresponding to this potential adheres to the drum-shaped photoconductor 7 to form a latent image. Development is performed.

Further, the image formed on the drum-shaped photoreceptor 7 is sent to the transfer roller 10. Also, the paper feed tray 1
The printing paper 13 conveyed by the paper feed roller 12 from 1 is positively charged from the back surface. The surface of the printing paper 13 is charged to a positive potential, and the developer 2 is attracted to the printing paper 13 by the action force of the electric field formed between the surface of the printing paper 13 and the drum-shaped photoconductor 7 to perform the transfer.

The print paper 13 on which the visible image is formed by transfer is conveyed to the fixing device 14 and fixed, and the fixed image is completed.

The developer 2 remaining on the drum-shaped photosensitive member 7 at the time of transfer is scraped off by the cleaning blade 15 before being charged again and accumulated in the waste developer container 16.

Using the image forming apparatus of this embodiment, 15
When 8000 sheets were continuously printed in each atmosphere of ℃, 15% (low temperature and low humidity) and 30 ℃, 80% (high temperature and high humidity), the developing portion was not caused in any atmosphere without causing excessive charging of the developer. Since it became possible to eliminate the insufficient supply of the developer to both ends, it was possible to obtain an output image without light edge density and uneven density at all points from the start of durability to the end of developer.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. In addition,
The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 4 is a cross-sectional view of the process cartridge according to the third embodiment of the present invention, FIG. 5 is a plan view of the internal floor of the developer container 17, and FIG. Show D
It is a sectional view in the D section.

This process cartridge is characterized in that the inclination angle of the floor surface of the developer container 17 is made larger at both end portions than the central portion in the longitudinal direction of the developing portion, and the process cartridge is detachably attached to the image forming apparatus. It is based on the premise that it has a mechanism for latent image formation, development, and cleaning.

In the present embodiment, the lengthwise dimension inside the developer container 17 is 340 mm. Further, the longitudinal length of the mounting portion of the developer container 3 of the developer container 17 is set to 300 m.
m, the developer container portion 17 and both ends of the floor surface and the developer container portion 1
The seven side walls were connected by a plane having an inclination angle of 45 degrees (angle e in FIG. 5). Furthermore, the inclination angle of the floor surface of the lower portion of the developer container 17 is 65 degrees with respect to the length of the mounting portion of the developer carrier 3 from the both ends of the container to 50 mm (see FIG. 4).
Medium angle f), 50 degrees in other ranges (angle g in FIG. 4)
And

The developer 2 used is the same as the developer used in the first embodiment. Developer container part 1
A stirring rod 18 having a diameter of 1 mm that rotates in association with the rotation of the drum-shaped photosensitive member 7 is installed in the drum 7.
Draws a circle with a radius of 20 mm and rotates in the direction of arrow E in FIG.

In the apparatus of this embodiment as described above,
The amount of the developer 2 in the developer container 17 is uniformly adjusted by the developer carrier 3 and the developer amount regulating member 4, and is conveyed to the surface of the drum-shaped photoreceptor 7 while being charged. On the other hand, the drum-shaped photoconductor 7 rotates from the image forming apparatus main body in the direction of the arrow in FIG.
300 at DC voltage of 600 V and peak-to-peak voltage of 1600 V
A bias voltage superposed with an AC voltage of a sine wave of Hz is applied through the charging roller 8 and the surface thereof is about -60.
It is charged to 0V. A latent image is drawn on the drum-shaped photoconductor 7 by irradiation light from a laser irradiation device (not shown) installed on the image forming apparatus main body side.

A bias voltage in which a DC voltage of -500 V and an AC voltage composed of a sine wave of 1800 Hz with a peak-to-peak voltage of 1600 V are superimposed is applied to the developer carrying member 5 from the main body of the image forming apparatus. The agent 2 is reciprocated between the drum-shaped photoconductor 7 and the developer carrier 5. At this time, the actual potential on the drum-shaped photoconductor 7 is a negative potential in both the bright portion and the dark portion of the latent image, and the developer 2 corresponding to this potential adheres to the drum-shaped photoconductor 7 to form a latent image. Development is performed.

Further, the image formed on the drum-shaped photosensitive member 7 is conveyed in the order of the transfer section and the fixing section provided in the main body of the image forming apparatus, and the fixed image is completed on the recording paper.

On the other hand, the developer 2 remaining on the drum-shaped photosensitive member 7 at the time of transfer is scraped off by the cleaning blade 15 before being charged again and accumulated in the waste toner container 19.

The process cartridge of this embodiment is mounted on the main body of the image forming apparatus, and the temperature is 8000 in each atmosphere of 15 ° C., 15% (low temperature and low humidity) and 30 ° C., 80% (high temperature and high humidity).
When continuous printing was performed on one sheet, it was possible to eliminate insufficient developer supply to both ends of the developing section without causing excessive charging of the developer in any atmosphere. At all points until the break,
It was possible to obtain an output image without light density and uneven density at the edges.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. In addition,
The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 7 shows a cross-sectional view of the process cartridge of the fourth embodiment of the present invention, FIG. 8 shows an internal floor shape of the developer container portion 20, and FIG. 9 shows FIG. Show F
It is a sectional view in the -F section.

This process cartridge differs from the process cartridge of the third embodiment of the present invention in that the shape of the developer container portion 17 is changed.
For the purpose of improving the fluidity of the developer 2 that wraps around from the end portion to the developing portion, the inside floor surface and the side wall of the developer container portion 20 having a uniform inclination angle are connected by a taper. is there.

In this embodiment, the floor surface of the developer container 20 is uniformly formed as a plane having an inclination angle of 50 degrees (angle h in FIG. 7). Furthermore, on the developing section side of the developer container section 20,
The angle between the floor surface of the developer container 20 and the side wall is 50 degrees (angle k in FIG. 8), and the angle between the floor surface and the side wall of the developer container 20 is 65 degrees (angle m in FIG. 8) on the rear end side of the container. ), The floor surface and the side wall of the developer container portion 20 are connected by a taper.
However, the width of the floor of the developer container 20 is set uniformly from the developing section side to the container rear end side.

The process cartridge of this embodiment is filled with the developer used in the first embodiment, and the temperature is kept at 15 ° C. for 15 minutes.
% (Low temperature and low humidity) and 30 ° C. and 80% (high temperature and high humidity) in each atmosphere, continuous printing of 8,000 sheets was performed. Since it became possible to eliminate the developer supply shortage, it was possible to obtain an output image without light edge density or density unevenness at any time from the start of durability to the end of developer in any atmosphere.

[0066]

According to the first invention of the present application, development is performed at both ends of the developer container at both ends of the developer container while keeping the inner floor inclination angle at the center of the developer container as small as possible. The agent increases the angle of inclination of the internal floor so that the agent can easily fall off due to the frictional resistance with the side wall of the developer container.
In the central part of the developer container, the developer is prevented from being excessively charged due to the developer being strongly rubbed against the developer carrier due to the pressure of the developer loaded above the developer container, and the developer to the both ends of the developing part is prevented. It is possible to solve the shortage of supply and prevent the density of the end portion of the developed image from being low.

According to the second aspect of the present invention,
The inclination angle is larger than the central portion in the longitudinal direction of the developer container.The inner floor surfaces of both ends of the developer container are provided with an inclination such that the side wall side of the developer container is higher than the central portion side of the developer container. Therefore, it is necessary to further improve the fluidity of the developer from both ends of the developer container to the developing part, solve the insufficient supply of the developer to both ends of the developing part, and prevent the density of the developed image end part from being thin. You can

Further, according to the third invention of the present application, the developer container is provided while keeping the inner floor inclination angle of the central part of the developer container of the developing device provided in the image forming apparatus as small as possible. At both ends, the internal floor inclination angle is increased so that the developer on both ends of the developer container shakes off the frictional resistance with the side wall of the developer container and falls easily. While preventing the developer from being over-charged by being strongly rubbed against the developer carrier by the pressure of the developer loaded on the upper side, the developer is provided in the entire longitudinal direction of the developing unit provided below the developer container. Since there is no excess or deficiency of the inflow, it is possible to prevent the density of the output image edge portion from being thin.

Further, in the fourth invention according to the present application, the inner floor surface of both ends of the developer container whose inclination angle is larger than the central part in the longitudinal direction of the developer container is closer to the central part side of the developer container. Also, since the side wall of the developer container is inclined so as to be higher, the flowability of the developer from both ends of the developer container to the developing section is further improved, and the developer is not spread over the entire longitudinal direction of the developing section. Since the flow is allowed to flow without any shortage, it is possible to prevent the density of the end portion of the output image from being low.

Further, according to the fifth invention of the present application, both ends of the developer container are kept with the inner floor surface inclination angle of the central part of the developer container of the developing device provided in the process cartridge kept as small as possible. In the section, the developer on both ends of the developer container has a large internal floor surface inclination angle so that the developer can easily fall off by shaking off the frictional resistance with the side wall of the developer container.
At the center of the developer container part, the developer is placed above the developer container part while preventing excessive charging of the developer which is caused by the pressure of the developer loaded on the developer container being strongly rubbed against the developer carrier. The developer is made to flow into the entire area of the provided developing unit in the longitudinal direction without excess or deficiency. Therefore, in the image forming apparatus equipped with this process cartridge, it is possible to prevent the density of the output image end portion from being low due to insufficient supply of the developer.

Further, in the sixth invention according to the present application, the inner floor surface of both ends of the developer container whose inclination angle is larger than the central part in the longitudinal direction of the developer container is closer to the central part side of the developer container. Also, since the side wall of the developer container is inclined so as to be higher, the flowability of the developer from both ends of the developer container to the developing section is further improved, and the developer is not spread over the entire longitudinal direction of the developing section. Inflow without deficiency. Therefore, in the image forming apparatus equipped with this process cartridge, it is possible to prevent the density of the output image end portion from being low due to insufficient supply of the developer.

[Brief description of drawings]

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

FIG. 2 is an internal view of a developer container used in the developing device according to the first embodiment of the present invention.

FIG. 3 is a sectional view of an image forming apparatus according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a process cartridge according to a third embodiment of the present invention.

FIG. 5 is an internal view of a developer container portion used in a process cartridge according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of the DD section shown in FIG. 4 in the process cartridge according to the third embodiment of the present invention.

FIG. 7 is a sectional view of a process cartridge according to a fourth embodiment of the present invention.

FIG. 8 is an internal view of a developer container portion used in a process cartridge according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view of the FF portion shown in FIG. 7 in the process cartridge according to the fourth embodiment of the present invention.

FIG. 10 is a sectional view showing a conventional developing device.

[Explanation of symbols]

 1 Developer Container 2 Developer 3 Developer Carrier 4 Developer Amount Control Member 6 Developer Container 7 Drum-Shaped Photoreceptor (Image Carrier) 17, 20 Developer Container Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsutoshi Ando 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. An internal floor surface of a developer container, in which a developing section provided with a developer carrier is arranged below a developer container, and a back side of the developer container is higher than a front side thereof. In a developing device which is provided with an inclination of a predetermined angle and supplies the developer to the developing section by dropping the developer by its own weight, the inclination angle of the inner floor surface of the developer container is larger than that of the central portion in the longitudinal direction of the developer container. A developing device, wherein both ends of the developer container in the longitudinal direction are made larger. 2. The side wall side of the developer container is higher than the center side of the developer container on the inner floor surface of both ends of the developer container whose inclination angle is larger than the center part of the developer container in the longitudinal direction. The developing device according to claim 1, wherein the developing device is provided with such an inclination. 3. A developing unit provided with an image bearing member carrying a latent image and a developer bearing member facing the image bearing member is disposed below a developer container, and the developing agent bearing member is provided. In an image forming apparatus having a developing device which is provided with an inclination of a predetermined angle on the inner floor surface of the developer container so that the back side is higher than the front side, and which supplies the developer to the developing portion by the weight drop of the developer, The image forming apparatus is characterized in that the inclination angle of the inner floor surface of the developer container is larger at both end portions of the developer container in the longitudinal direction than at the central portion in the longitudinal direction of the developer container. 4. The side wall side of the developer container is higher than the center side of the developer container on the inner floor surfaces of both ends of the developer container whose inclination angle is larger than the center part of the developer container in the longitudinal direction. The image forming apparatus according to claim 3, wherein the inclination is as follows. 5. A developing unit provided with an image bearing member carrying a latent image and a developer bearing member facing the image bearing member is disposed below a developer container, and the developing agent bearing member is provided. An image forming apparatus having a developing device, in which the inner floor surface of the developer container is inclined at a predetermined angle so that the back side is higher than the front side, and the developer is supplied to the developing portion by the weight drop of the developer. In the process cartridge detachably attachable to the main body, the inclination angle of the inner floor surface of the developer container is larger at both ends of the developer container in the longitudinal direction than at the longitudinal center of the developer container. And process cartridge. 6. The side wall side of the developer container is higher than the center side in the longitudinal direction of the developer container on the inner floor surfaces of both ends of the developer container whose inclination angle is larger than the center in the longitudinal direction of the developer container. The process cartridge according to claim 5, wherein the inclination is as follows.