JPH1138742A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of distortion of a developer replenishing path and prevent the developer concentration on a formed image from being unstabilized by providing ribs fastening the upper face and bottom face of the developer replenishing on the developer supply path. SOLUTION: The upper face 5 and the lower plate 25a of a toner replenishing path are fastened together at both end sections P in the width direction, and multiple ribs 30 supporting the upper face 5 and the lower plate 25a of the toner replenishing path are provided at uniform intervals in the longitudinal direction. If the upper face 5 and the lower plate 25a of the toner replenishing path are fastened at both end sections P only, the strength of the faces is weak, and the distortion of the toner replenishing path is easily generated by external force such as the force of the toner flowing inside. When the ribs 30 are provided, the upper face 5 and the lower plate 25a of the toner replenishing path can be prevented from being deformed by the external force, and the vertical interval of the toner path can be kept at the desired interval. The toner density can be prevented from being unstabilized by the distortion of the toner replenishing path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used for an image forming apparatus such as a copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art Conventionally, in a developing device in which a developer carried on a developer carrier is supplied to a latent image carrier and used for development, the developer consumed by the development is transferred from the developer carrier to the latent image carrier. There has been proposed one configured to replenish the body side through a developer supply path.

For example, Japanese Patent Application Laid-Open No. Hei 1-96673 discloses that a two-component developer composed of a mixture of a toner and a carrier is carried on a developer carrying member and applied to the surface of the latent image carrying member, and the latent image on the surface of the latent image carrying member is exposed. A developing device for developing an image,
A developer accommodating portion accommodating a developer for the developer carrying member, a toner accommodating portion communicating with the developer accommodating portion via a toner replenishing opening, and replenishing the toner in the toner accommodating portion with the toner. A toner conveying member for moving toward the opening, and a developer retaining portion provided in the vicinity of the developer replenishing portion on the side of the toner replenishing opening, the developer retaining portion being provided with a developer in the developer storing portion; Is in the volume amount state corresponding to the toner concentration in the proper range, the developer sufficiently enters and stays there, and the toner supply opening is closed by the staying developer, so that the toner concentration is lower than the proper range. When the volume is reduced to a state corresponding to the volume level, the amount of accumulated developer decreases or the amount of accumulated developer stops, and the toner storage unit communicates with the developer storage unit via the toner supply opening. Exists in Discloses a developing apparatus is characterized in that.

In the developing device described in Japanese Patent Application Laid-Open No. 1-96673, when the toner concentration of the developer is in an appropriate range, the developing device in which the toner replenishing opening for replenishing the toner to the developer retaining portion is retained is provided. Closed by the agent and no toner is replenished. On the other hand, when the toner is consumed by the developing action, the toner concentration of the developer decreases and the volume of the developer decreases, and the developer remaining in the toner supply opening portion disappears. Try to return to. As a result, the toner concentration (defined by the weight ratio of the magnetic particles and the toner) of the developer including the toner and the magnetic particles (carrier) falls within a certain range.

In such an unused state of the developing device (between the time when the manufactured developing device reaches the user and is used),
It is desirable that the developer and the toner are each sealed. The reason is prevention of dirt due to toner scattering, and
This is to prevent the developer and the toner, which have been previously mixed at a predetermined density, from being mixed.

The applicant of the present invention has previously filed Japanese Patent Application No. 9-15 / 1997.
No. 8085, a developer carrying member for carrying a developer composed of toner and magnetic particles on the surface, a magnetic field generating portion arranged inside the developer carrying member, and a developer carrying member, A developer regulating member for regulating the amount of the developer, and a developer accommodating portion for forming a developer stagnant portion in which the developer stopped by the developer regulating member to stagnate is formed between the developer carrying member and the developer accommodating portion. A developing device including a case, a toner hopper unit for storing toner, and a toner supply path connecting the toner hopper unit and the developer retaining unit;
The developing device is characterized in that the developer is sealed and filled in advance in the toner supply path in an unused state.

FIG. 1 is a schematic configuration diagram of a developing device proposed in Japanese Patent Application No. 9-158085. In this developing device, in order to sufficiently replenish the toner 3 of the toner hopper 10 to the developer retaining section 4, the toner 3 can be satisfactorily conveyed from the toner hopper 10 through the toner replenishing path 11 leading to the developer retaining section 4. desirable. Further, the wall surface of the toner supply path 11 needs to be strong enough to withstand the movement of the toner 3 passing therethrough and the change of the environment over time.

[0008]

However, conventionally, the upper surface 5b and the lower surface 25a forming the toner supply path 11 are conventionally used.
Has been conceived to be supported only at both ends in the width direction. FIG. 12 is a perspective view of the vicinity of a conventionally proposed toner supply path 11. In this figure, the toner supply path 11
Both ends P in the longitudinal direction such that the surface 5b regulating the lower part of the developer accommodating case and the lower supply path plate 25a provided for regulating the bottom surface of the toner supply path 11 face each other at a predetermined interval. Has only been concluded. For this reason, since the supply path lower plate 25a is not supported except at both ends P, it tends to bend particularly in the vicinity of the central portion Q in the longitudinal direction. As a result, the upper and lower widths of the toner supply path 11 are reduced in the longitudinal direction or the toner transport direction. The distortion of the toner supply path 11 that becomes uneven is likely to occur. When the toner supply path 11 is distorted, the toner supply to the developer carrier is not performed uniformly, and the toner density may become unstable on the formed image.

Further, as in the developing device shown in FIG. 1, the toner 3 in the toner hopper 10 is forcibly removed.
In the apparatus provided with the toner supply member 13 for replenishing the toner supply path, the toner 3 is excessively supplied to the toner supply path 11, the internal pressure of the toner supply path is increased, and the distortion of the toner supply path is promoted. The fluidity of the toner in the toner supply path 11 deteriorates, or the pressure of the toner 3 on the downstream side in the developer conveyance direction including the toner supply path 11 rises to press the developer carrier 7, and the developer carrier 7 There is a possibility that the toner concentration may become unstable due to torque applied to the rotation of the toner.

Such a problem is not limited to the developing device 1 shown in FIG. 1, and any one or both of the upper surface and the lower surface of the developer supply path may be supported only at both ends in the width direction.
It is thought that it may occur.

The present invention has been made in view of the above problems, and a first object of the present invention is to prevent the developer supply path from being distorted and to make the developer concentration unstable on a formed image. It is an object of the present invention to provide a developing device which can prevent the occurrence of the problem.

A second object of the present invention is to provide a developing device capable of preventing an excessive supply of a developer to a developer supply path and preventing a developer concentration on a formed image from becoming unstable. To provide.

[0013]

In order to achieve the first object, a developing device according to a first aspect of the present invention includes a developing device that carries a developer on a surface thereof and covers the developing device in a region facing a latent image carrier of an image forming apparatus. A developer carrier that transports the developer, a developer accommodating section that accommodates a developer for replenishing the developer carrier, and an area between the developer accommodating section and the developer carrier; A developer supply path extending in the width direction of the developer carrying member and through which the developer passes, and a developer carrying means for carrying the developer from the developer accommodating portion to the developer carrying member. Wherein at least one of an upper surface that regulates an upper portion of the developer supply passage and a bottom surface that regulates a bottom portion is formed of a plate-like member supported only at both widthwise ends of the developer supply passage. In the apparatus, a rib for fastening an upper surface and a bottom surface of the developer supply path is provided with the developer supply path. It is characterized in that provided in the.

According to the first aspect of the present invention, the rib fixedly supports the gap between the upper surface and the bottom surface at a position between both ends in the width direction of the developer supply path with respect to the developer transport direction. Are hardly deformed in a direction of approaching or separating from each other. This makes it difficult for the top and bottom surfaces to bend even when subjected to an external force due to a change in the environment over time or the movement of the developer passing through the inside, so that the shape of the developer supply path does not change. This makes it possible to maintain a desired interval between the upper and lower portions of the developer supply path, thereby preventing the developer supply path from being distorted in the width direction or the developer transport direction, thereby preventing the developer supply path from being distorted. The developer is supplied to the developer carrier uniformly in the width direction.

According to a second aspect of the present invention, there is provided the developing device according to the first aspect, wherein the developing device carries a developer comprising toner and magnetic particles on a surface thereof, and the developer carrier. A developer generating member disposed inside the developer carrying member, a developer regulating member for regulating the amount of developer carried on the developer carrying member, and a developing device in which the developer stopped by the developer regulating member is retained. The image forming apparatus further includes a developer accommodating case for forming a developer retaining section between the developer carrying member and the toner accommodating section as the developer accommodating section.

In the developing device according to the second aspect, when the toner is consumed by the development and the toner concentration of the developer decreases, the developer remaining in the opening of the developer supply path on the side of the toner container disappears. The toner enters and attempts to return to a predetermined toner density. At this time, the upper and lower intervals of the developer supply path are not made uneven in the toner transport direction or the width direction in the toner transport direction, and the amount of toner taken into the developer retaining portion from the developer supply path is not equal to the above-mentioned interval. Prevent from being influenced by uniformity. As a result, it is possible to prevent the amount of toner supplied from the developer retaining portion to the developer carrier from becoming uneven due to distortion of the developer supply path.

According to a third aspect of the present invention, in the developing device of the first or second aspect, the rib is formed of a plate-like member parallel to the developer conveying direction, and the width of the rib is set to the developer accommodating portion. It is characterized in that it is formed to be thinner as it approaches the developer carrier from the side.

FIG. 2A is a plan view showing the state of the developer passing near the plate-like rib 30. FIG. In the case where the ribs 30 having a constant width W are provided in parallel to the developer transport direction as shown in this figure, the developer passing from the rear to the front along the side surfaces of the ribs 30 has the ribs 30 cut off. From there, the ribs gradually enter the space on the developer carrier side of the rib (hereinafter, referred to as the front side of the rib), but a space E in which the developer does not exist is formed near the front side of the rib 30. When the developer is replenished to the developer carrying member at a position including the space E, the amount of developer supplied to the developer carrying member corresponding to the space E is increased from the position other than the space E to the developer carrying member. There is a possibility that the amount of developer supplied becomes smaller than the supply amount.

In the developing device according to the third aspect, the rib is formed so as to be thinner toward the developer carrier (hereinafter referred to as a tip). FIG. 2B is a plan view of a rib having a thin tip. According to this configuration, since the developer passing through the side of the rib advances obliquely along the side surface of the rib, the developer further enters the space near the tip of the rib from where the rib is cut off.

According to a fourth aspect of the present invention, in the developing device of the first, second or third aspect, the rib is provided between the central portion of the developer supply path in the developer transport direction and the upstream side in the developer transport direction. It is characterized by being provided in a region.

According to a fourth aspect of the present invention, in the developing device, the rib is disposed on the upstream side of the developer supply path from the central portion in the developer transporting direction in the developer transporting direction, and the developer carrier on the downstream side from the central portion in the developer transporting direction. There should be no ribs in the vicinity. As a result, even if there is a space E in which no developer exists near the tip of the rib as shown in FIG. 2A, a sufficient space for the developer to enter from this space to the developer carrier can be formed. At the position where the developer is replenished to the developer carrier, the developer is uniformly present regardless of whether or not the rib exists on the upstream side. This prevents a difference in the amount of developer supplied to the developer carrier.

According to a fifth aspect of the present invention, there is provided a developing device according to the first aspect.
Alternatively, in the developing device of the fourth aspect, in an upstream area of the developer supply path in the developer transport direction, a distance between the upper surface and the bottom surface is increased as approaching the rib.

In the developing device according to the fifth aspect, the distance between the upper surface and the lower surface of the developer supply path increases as the distance from the rib increases.
Make the developer flow more. Here, in the developer supply path, since the developer does not flow to the position where the rib is provided, the amount of the developer is smaller than the position where the rib is not provided on the side of the rib on the developer carrier. If left as is, there may be a difference in the amount of developer supplied to the developer carrier between the position where the rib is provided and the position where the rib is not provided. In the upstream area in the developer transport direction, the vertical interval of the developer supply path near the rib is increased, and the amount of the developer flowing from the developer accommodating portion is increased nearer to the rib than at a position farther from the rib. Then, a part of the developer that has flowed in the vicinity of the rib flows into the front side of the rib, and as a result, the developer is uniformly present in the front side region of the rib in the longitudinal direction of the developer carrier. Thus, the amount of the developer pumped to the developer carrying member is prevented from being different depending on whether or not the rib is provided on the upstream side in the developer conveying direction. Further, in the region of the developer supply path on the developer carrier side, the distance between the top surface and the bottom surface is not set as described above. This is to make the distance between the upper surface and the bottom surface closer to the developer carrier non-uniform so that the influence does not directly affect the amount of the developer supplied to the developer carrier. .

In order to achieve the second object,
According to a sixth aspect of the present invention, there is provided the developing device according to the first, second, third, fourth, or fifth aspect, wherein the developer for supplying the developer in the developer accommodating section to the developer replenishing passage is fed into the developer accommodating section. A developer supply member having a blade member, and a protrusion formed by protruding an end of the rib on the developer storage portion side toward the developer storage portion, wherein the blade member protrudes from the rib. , And has flexibility.

According to the sixth aspect of the present invention, the tip of the blade member of the developer supply member for feeding the developer in the developer accommodating section to the developer supply path is provided at the projecting portion of the rib projecting toward the developer accommodating section. Abut Since the blade member has flexibility, the blade member continues to rotate while being bent according to the shape of the rib, and returns to the original shape after passing the position where it comes into contact with the protruding portion. In a state in which the blade member is bent by the protruding portion of the rib, the amount of the developer put on the blade member is small, and the distance from the tip of the blade member to the developer inlet of the developer supply path becomes long. The amount of developer taken into the developer supply path is smaller than when the member is not bent. This prevents the developer supply member from feeding an excessive amount of developer into the developer supply path, prevents the pressure of the developer in the developer supply path from rising, and prevents an excessive amount of developer from being supplied to the developer carrier. This prevents a decrease in torque and fluidity of the developer in the developer supply path.

Here, the amount of protrusion of the protrusion and the flexibility of the blade member may be selected so that the amount of developer supplied into the developer supply path is appropriate.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device using a two-component developer composed of toner and magnetic particles will be described below.

[Embodiment 1] The developing device 1 according to the present embodiment has the same general configuration as the conventionally proposed developing device shown in FIG. 1, so that the entire developing device will be described with reference to FIG. This developing device, as shown in FIG.
A developer storage case 5 for storing a developer having a toner and a toner 3 and forming a developer stagnant portion 4, and a latent image carrier (for example, a photosensitive drum) 100 for carrying a latent image, and the toner A developing section (development area) 6 for supplying to the carrier 100 is formed, and a developing sleeve 7 as a developer carrier for carrying and transporting the developer from the developer retaining section 4 to the developing section 6 is provided inside the developing sleeve 7. A magnet roller 8 as a magnetic field generating means provided with a plurality of magnetic poles N1, N2, S1, and S2 fixedly disposed thereon, and an amount of the developer carried on the developing sleeve 7 and conveyed to the developing unit 6 (the amount of the developer layer) Developer regulating member 9 for regulating the layer thickness), a toner hopper 10 provided adjacent to the developer accommodating case 4 and serving as a toner accommodating portion for accommodating the toner 3 for replenishment, a toner hopper 10 and a developer stagnation portion And a toner supply path 11 communicating and. The toner supply path 11 has a top surface 5b extending below the developer storage case 5, and a bottom surface formed by a supply path lower plate 25a. The toner supply path 11 is a characteristic part of the present embodiment, and will be described later in detail. Further, the toner supply path 11 is provided with sealing seals 14 and 15 for sealing the developer inside, so that the toner supply path 11 is not mixed with the toner and the developer inside the toner hopper 10 and the developer storage section 4 when not in use. It has become.

Around the latent image carrier 100, a primary charging device (not shown), an image exposure or image writing device, a toner image transfer device to a transfer sheet, and a surface of the latent image carrier 100 after the toner image is transferred are shown. A cleaning device or the like for cleaning the toner image is provided, and a toner image is formed on transfer paper by a well-known electrophotographic process. Needless to say, a fixing device for fixing the toner on the transfer paper onto which the toner image has been transferred is also provided in the image forming apparatus. (Hereinafter, margin)

The developer stagnation section 4 includes a developer case 5 and a developer regulating member 9. Toner hopper 1
0 denotes a side wall 5 of the developing device case 12 and the developer storage case 5.
a. The toner hopper 10 is provided with a toner replenishing member 13 for feeding the replenishing toner 3 to the toner replenishing path 11 while stirring. Toner supply member 13
Is composed of a shaft portion 13a and a blade member 13b having one end fixed to the shaft portion 13a. The toner replenishing member 13 is rotated in conjunction with the rotation of the developing sleeve 7.

In the developing device having the above structure, when the sealing seals 14 and 15 are removed and attached to a predetermined position of the image forming apparatus and the operation of the developing device 1 is started, the developing sleeve 7 is rotated counterclockwise. Along with the rotation in the direction of arrow A, the developer regulated to a constant layer thickness by the developer regulating member 9 starts to be conveyed to the surface of the developing sleeve 7 and is filled in the toner supply path 11. The developer is gradually taken into the developer retaining section 4. Toner hopper 1
The toner replenishing member 13 is rotated clockwise (in the direction of arrow B) to start the replenishing operation of the toner 3. However, since the toner replenishing path 11 is closed by the developer, the developer accumulating portion 4 and the developing sleeve 7 are not supplied with the toner 3 for replenishment.

As the rotation of the developing sleeve 7 is continued, a uniform developer layer is formed on the entire surface of the developing sleeve 7. In an initial state where the development is not yet performed, the amount of the developer to be filled in the developer retaining section 4 and the toner replenishing path 11 is so set that the gap connecting the developer retaining section 4 and the toner replenishing path 11 is filled with the developer. Is adjusting. In a state in which the gap is filled with the developer, even if the toner 3 for replenishment is sent by the toner stirring member 13, the maximum volume (bulk) of the developer that can be stored in the developer storage case 5 is stored. , The toner 3 cannot enter the developer retaining section 4. Therefore,
The toner concentration of the developer in the developer retaining section 4 is maintained within a predetermined concentration range at the time when the developer is filled.

When the toner is consumed by developing the toner image on the latent image carrier 100 rotated clockwise (in the direction of arrow C), the amount of consumed toner in the developer retaining section 4 is reduced. The volume (bulk) of the developer decreases. Due to the decrease in the volume (volume) of the developer in the developer retaining section 4, the toner 3 for replenishment enters the developer retaining section 4 from the gap at the lower portion of the developer accommodating case 5, and the toner concentration is kept constant.

Next, the features of this embodiment will be described. FIG. 3 is a perspective view of the toner supply path 11 in the developing device of the present embodiment. In this figure, the upper surface 5b of the toner supply passage 11 and the lower supply plate 25a are not only fastened at both ends P in the width direction, but also support the upper surface 5b and the lower supply plate 25a at equal intervals in the longitudinal direction. A plurality of ribs 30 are provided.

If the upper surface 5b of the toner supply path 11 and the lower plate 25a of the supply path are fastened only at both ends, the strength of each surface is weak, and the external force such as the pressure of the toner flowing inside causes the toner supply path 11 Distortion easily occurs. By providing the rib 30, the upper surface 5b of the toner supply path 11 and the supply path lower plate 25a can be prevented from being distorted by an external force.
The vertical interval of the toner supply path 11 can be maintained at a desired interval. This can prevent the toner concentration from becoming unstable due to the distortion of the toner supply path 11.

FIG. 4 is a sectional view taken along the line DD of FIG. The rib 30 is formed in a pointed shape such that its width becomes thinner toward the tip end 30a, and the rib 30 is disposed on the upstream side of the toner transport direction from the central portion R of the toner supply path 11 in the toner transport direction. , Are not provided in a region downstream of the central portion R.

By forming the tip 30a of the rib 30 into a pointed shape as described above, as shown in FIG.
Since the toner passing along the side of the rib 30 advances obliquely along the side surface of the rib 30, the toner enters the space near the tip of the rib 30 from the place where the rib 30 is interrupted, and is moved from the tip 30a of the rib 30 to the developing sleeve 7 side. Does not create a space in which no toner exists. In addition, by regulating the arrangement of the ribs 30 as described above, the tip 30a of the rib 30 should be used.
Even if there is a space in which toner does not exist in the vicinity, a space into which toner can enter from this space to the developing sleeve 7 can be sufficiently formed, and the rib 30 is located at a position in the toner supply path 11 where toner is supplied to the developing sleeve 7. A difference is not caused in the amount of toner between the existing part and the non-existing part.

Thus, it is possible to prevent a difference in the amount of toner supplied to the developing sleeve 7 depending on whether or not the rib 30 is present on the upstream side in the toner conveying direction, and the toner density on the formed image becomes unstable. Can be prevented.

Next, a modification of the developing device of this embodiment will be described. FIG. 5 is a perspective view of the vicinity of the toner supply path 11 in which the upper and lower distances between the upper surface 5b of the toner supply path 11 and the lower plate 25a of the supply path according to the modification are partially changed.
It is the perspective view which looked at the surface in which the rib 30 of the supply path lower plate 25a was provided, and the rib 30 diagonally. In FIG. 5, the vertical interval of the toner supply path 11 is made larger as approaching the rib 30, and narrower as approaching the intermediate portion between the ribs 30. As shown in FIG. 6, the rib 30 in the present modification also extends only up to the center of the toner supply path 11, and has a tapered end on the side of the developing sleeve 7 that is gradually thinner. In the downstream region of the toner supply path 11, that is, in the range where the rib 30 is not provided, the vertical interval is formed so as to be uniformly wide similarly to the vicinity of the rib 30 in the region where the rib 30 is provided. .

By forming the upper and lower intervals of the toner supply path 11 as described above, in the upstream area where the ribs 30 are provided, more toner flows toward the ribs 30 and flows further away from the ribs 30. The amount is low. Here, in the toner supply path 11, the toner does not flow to the position where the rib 30 is provided.
The amount of toner on the side of the rib 30 on the side of the developing sleeve 7 is smaller than that of the position without the rib 30. If left unchanged, there may be a difference in the amount of toner supplied to the developing sleeve 7 between the position where the rib 30 is located upstream of the toner transport direction and the position where the rib 30 is not located. As in the present embodiment, when the amount of toner flowing from the toner hopper 10 in the upstream area in the toner conveying direction is larger near the rib 30 than at a position farther from the rib 30, a part of the toner flowing near the rib 30 is reduced. Flowing into the front side of the rib 30 results in the rib 3
In the front region of 0, the toner is uniformly present in the longitudinal direction of the developing sleeve 7.

As a result, when the toner is pumped to the developing sleeve 7, the rib 30
It is possible to prevent unevenness in the toner supply amount between the position where the toner is provided and the position where the toner is not provided. In the region of the toner supply path 11 on the side of the developing sleeve 7, the distance between the upper surface 5b and the supply path lower plate 25a is made uniform. As a result, the distance between the upper surface 5b on the side closer to the developing sleeve 7 and the lower supply plate 25a is made non-uniform, so that the influence directly affects the amount of toner supplied to the developing sleeve 7. Can be prevented. As described above, according to the modified example of the present embodiment, it is possible to more effectively prevent the toner density from becoming unstable on the formed image.

[Second Embodiment] Next, a developing device according to a second embodiment will be described. FIG. 7 is a plan view showing the shape of the rib 30 of the developing device according to the second embodiment, and FIG.
FIG. 4 is a cross-sectional view of the developing device cut along a plane including the shaft portion 13a of the toner supply member 13 in the same manner. FIG. 9 is a perspective view of the toner supply path 11. In FIG. 7, the rib 30
Of the rib 30 protrudes toward the toner hopper 10 from the toner supply path 11 to form a protruding portion 30b of the rib 30. Projecting portion 30b of rib 30
As shown in FIG. 8, all ribs 30 have the same protrusion width toward the toner hopper 10 side. Further, as shown in FIG. 9, in the present embodiment, the protrusion 30b
Is vertically cut from top to bottom.

FIG. 10 is an explanatory view showing the state movement of the blade member 13b of the toner stirring member 13 in the developing device according to the second embodiment. FIG. 11 is an enlarged perspective view of the toner stirring member 13. As shown in FIG. 10, the tip of the blade member 13b of the toner replenishing member is sufficiently softer than the rib 30 so as to bend when it comes into contact with the protrusion 30b of the rib 30, and after passing through the protrusion 30b of the rib 30, it returns to its original state. It is made of a flexible material that returns to the shape shown in FIG. In addition, the toner hopper 10 has such a strength that the toner in the toner hopper 10 can be stirred. The material of the blade member 13b can be, for example, a polyester film of about 0.1 to 0.2 mm. In addition, as the material of the blade member 13b, foamed rubber, polyurethane, or the like can be used. On the other hand, as a material of the rib 30, a hard plastic or the like can be used. The developing device shown in FIG. 10 differs from the developing device shown in FIG. 7 in that the bottom surface of the toner supply path 11 is also used as the surface on which the developing device case 12 extends. Regarding this, either of them may be used in the present embodiment. The remaining configuration is the same as that of the developing device in FIG. Further, as shown in FIG. 11, the toner stirring member 13
a rectangular blade member 13 having a length up to the center in the longitudinal direction of a
Using two pieces of b, the free ends are fixed to the shaft portion 13a such that their free ends are opposite to each other in a direction perpendicular to the axial direction of the shaft portion 13a. By forming the toner stirring member 13 in this manner, the load on the toner stirring member 13 is reduced.

In the developing device having the above structure, when the toner stirring member 13 rotates and the tip of the blade member 13b comes into contact with the protruding portion 30b of the rib 30, the blade member 13b is bent, and the tip of the blade member 13b is 11 upper surface 5
b, and passes through a position retracted toward the toner hopper 10 by a distance equal to the protrusion distance of the protrusion 30b from the entrance of the toner supply path 11 connecting the end of the supply path lower plate 25a to the toner hopper 10 side. As a result, the excessive toner falls into the toner supply path 11 toward the toner hopper 10 and is not packed into the toner supply path 11. Then, after passing through the protruding portion 30b of the rib 30, it returns to its original shape again by its own flexibility.

Here, when the protrusion 30b of the rib 30 is not provided as in the modification of the first embodiment and the first embodiment, the blade member 1 of the toner replenishing member 13 is not provided.
Since the tip of 3b rotates while being in contact with the entrance of the toner supply path 11, there is a risk that the toner supply path 11 may be excessively packed with toner. In the second embodiment, since it is possible to prevent excessive toner from being packed in the toner supply path 11, the toner supply path 11 caused by too much toner is packed.
It is possible to prevent a decrease in the fluidity of the developer inside and an increase in the driving torque of the developing sleeve 7 due to the pressing of the developer against the developing sleeve 7. Further, since the rise in the pressure of the toner to the toner supply path can be prevented, the deformation of the toner supply path caused by the increase in the pressure of the toner can be prevented, and the toner density can be prevented from becoming unstable on the formed image.

[0046]

According to the first aspect of the present invention, there is provided an excellent effect that distortion of the developer supply path can be prevented and the developer concentration on the formed image can be prevented from becoming unstable. is there.

According to the second aspect of the present invention, there is provided a developing apparatus having a configuration in which the toner density is self-controlled by changing the bulk of the developer in the developer retaining section according to the state of the toner being taken into the developer retaining section. In the apparatus, there is an excellent effect that the toner concentration can be prevented from becoming non-uniform due to the distortion of the developer supply path.

According to the third aspect of the present invention, since no space is provided on the side of the rib on the side of the developer carrier where no developer exists, the developer carrier is replenished in the vicinity of the tip of the rib and in the area where the rib does not exist. So that there is no difference in the amount of developer,
There is an excellent effect that the developer density on the formed image can be prevented from becoming unstable.

According to the developing device of the fourth aspect, at the position where the developer is supplied to the developer carrier in the developer supply path, the amount of the developer does not change due to the presence or absence of the rib on the upstream side in the developer transport direction. This has an excellent effect that the developer concentration on the formed image can be prevented from becoming unstable.

According to the developing device of the fifth aspect, there is an excellent effect that the developer concentration on the formed image can be prevented from becoming unstable.

According to the developing device of the sixth aspect, it is possible to prevent the developer from being excessively supplied to the developer supply path and prevent the developer concentration on the formed image from becoming unstable. Has an excellent effect. Further, since an increase in the internal pressure of the developer supply path can be prevented beforehand, there is an excellent effect that distortion of the developer supply path due to an increase in the internal pressure can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a developing device proposed in Japanese Patent Application No. 9-158085.

FIG. 2A is a plan view showing a state of a developer passing near a rib. (B) is a plan view of a rib having a thin tip.

FIG. 3 is a perspective view of a toner supply path in the developing device according to the first embodiment.

FIG. 4 is a sectional view taken along line DD in FIG. 3;

FIG. 5 is a perspective view of the vicinity of a toner supply path in which a distance between an upper surface and a supply path lower plate according to a modification of the first embodiment is partially changed.

FIG. 6 is a perspective view of a surface of the lower plate of the supply path on which ribs are provided.

FIG. 7 is a plan view of a developing device according to a second embodiment.

FIG. 8 is a cross-sectional view of the developing device cut along a plane including a shaft of the toner supply member.

FIG. 9 is a perspective view of the same toner supply path.

FIG. 10 is an explanatory view showing a state of a blade member of the toner stirring member when a rib is provided.

FIG. 11 is an enlarged perspective view of the toner stirring member.

FIG. 12 is a perspective view showing the vicinity of a conventionally proposed toner supply path.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing device 2 Magnetic particle 3 Toner 4 Developer storing part 5 Developing material storage case 5b Upper surface 7 Developing sleeve 8 Magnetic field generating part 9 Developer regulating member 10 Toner hopper 11 Toner supply path 12, 22 Developing device case 13 Toner stirring member 13b Blade Member 25a Lower plate of supply path 30 Rib 30b Projecting portion E Space where developer does not exist

Claims (6)

[Claims] A developer carrying member for carrying the developer on a surface of the image forming apparatus which faces the latent image carrying member; and a developer for replenishing the developer carrying member. A developer accommodating portion to be accommodated, and a developing device which is located in a region between the developer accommodating portion and the developer carrying member, extends in the width direction of the developer carrying member, and in which the developer passes inside. A developer supply path, and a developer carrying means for carrying the developer from the developer accommodating section to the developer carrier side; and at least a bottom surface regulating an upper part and a bottom part regulating an upper part of the developer supply path. In a developing device, one of which is formed of a plate-like member supported only at both ends in the width direction of the developer supply path, a rib for fastening an upper surface and a bottom surface of the developer supply path is connected to the developer supply path. A developing device, comprising: 2. The developing device according to claim 1, wherein said developing device is arranged inside a developer carrying member for carrying a developer composed of toner and magnetic particles on a surface thereof. Magnetic field generating means, a developer regulating member for regulating the amount of developer carried on the developer carrying member,
A developer accommodating portion for forming between the developer carrying member and a developer accumulating portion for accumulating the developer whose progress has been prevented by the developer regulating member; and a toner accommodating portion as the developer accommodating portion. And a developing device. 3. The developing device according to claim 1, wherein the rib is formed of a plate-like member parallel to the developer conveying direction, and the width of the rib is set from the side of the developer accommodating portion to the developer carrying member. A developing device characterized in that the developing device is formed to be thinner as approaching the body side. 4. The developing device according to claim 1, wherein the rib is provided in a region of the developer replenishment path upstream from a central portion in the developer transport direction with respect to the developer transport direction. Characteristic developing device. 5. The developing device according to claim 1, wherein an interval between the upper surface and the bottom surface is increased in an upstream area of the developer supply path in a developer conveying direction as the distance from the rib increases. A developing device. 6. The developing device according to claim 1, wherein a rotating blade member for feeding the developer in the developer accommodating section into the developer supply path into the developer accommodating section. And a protruding portion formed by protruding an end of the rib on the developer accommodating portion side toward the developer accommodating portion, wherein the blade member contacts the protruding portion of the rib. A developing device extending to a position and having flexibility.