JP2001166574A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently and stably feed developer to a developing roll even when an image forming device is installed inclined. SOLUTION: The developer is carried from axial direction center toward both ends in an agitating roll 4 that is arranged in parallel to developing roll 2 and approaches closest to it by deviating a chamfer position formed on a blade on both of right and left sides in the axial direction by 180 degrees against the blade that is attached in an inclined state to a rotating shaft 6 or reversing the inclination of the blade. Or else, a space between the blades on both end parts is made narrower than at a central part and the developer carrying force is made stringer at the both end parts. The developer can be carried to the end parts by the agitating roll 4 even when an image forming device is inclined and the developer can be fed to the developing roll 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly to a latent image on a photosensitive member using a developer in which powder toner and magnetic particles (carrier) are mixed. The present invention relates to a developing device that supplies an image to an image to visualize the image.

[0002]

2. Description of the Related Art Conventionally, as a developing device used in an image forming apparatus such as a copying machine or a printer, for example, FIG.
As shown in FIGS. 6 and 17, a developer carrying member 2, a developer regulating member 3, and a plurality of developer stirring members 4,
5 and the like are well known. In such a developing device, a developing roller 2 which is a developer carrier is disposed so as to face the photoreceptor, and stirring rollers 4 and 5 which are developer stirring bodies are disposed in parallel with the developing roller 2. The rotational driving force from the motor is transmitted so as to rotate in the direction. The toner replenished into the case 1 from a toner replenishing unit (not shown) is conveyed in the axial direction by the stirring rollers 4 and 5, and is supplied to the developing roller 2 while being stirred.

A magnetic particle layer is formed on the surface of the developing roller 2, and the particles of the magnetic particle layer move with the rotation of the developing roller 2 to become a developer in which toner and magnetic particles are mixed. The thickness of the developer is regulated by the developer regulating member 3, and is conveyed to the developing area of the photoconductor.

[0004] Specific examples of the developing device as described above include (1) a developing device of an electrophotographic apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 5-197283, and (2) a developing device of Japanese Utility Model Application Laid-Open No. 5-8377.
The developing device of an electrophotographic copying machine disclosed in Japanese Patent Publication No. 6 (1994) is mentioned. In the developing device of (1), a partition plate is provided between two screws corresponding to the stirring roller, and a transfer vehicle is provided at a position between the ends of the screws and between the screws. This makes it possible to reliably stir and pulver the supplied toner mass, thereby avoiding the occurrence of stains during image formation. on the other hand,
In the developing device of (2), the inclination direction at the end portion of the feed fin of the screw in the feed direction is opposite to the tilt direction at other portions. As a result, the uneven distribution of the developer at the end of the screw on the feed direction side is avoided, and the screw is well supported for rotation.

[0005]

Here, in image forming apparatuses such as copying machines and printers, recently, demands for downsizing and personal use have been increasing. For this reason, the overall height (depth) of the case 1 of the developing device is often designed to be small from the viewpoint of space saving and restrictions on the arrangement inside the device. It is desirable that such an image forming apparatus provided with a developing device having a shallow overall height of the case 1 is installed in a horizontal position as much as possible and used for an image forming operation.

[0006] However, particularly in a personal machine and the like, it is very often not installed according to this principle. For example, popular machines and large machines are installed after a service person checks the level of the installation place with a level, etc., but personal machines are almost always installed in desired places by users. Therefore, it may not be installed on a horizontal place. In this case, an improper installation method of the image forming apparatus causes poor image quality and unforeseen troubles, resulting in a problem that many complaints are received.

[0007] In a developing device provided in a popular machine or a large-sized machine, since the case 1 has a sufficient height, a large amount of developer is stored in the developing device. for that reason,
Even if the image forming apparatus is inclined due to the improper installation as described above, as shown in FIG. 18, the developer comes into contact with most of the stirring roller 4 in the axial direction. It is possible to supply and to some extent absorb the influence of the inclination.

However, in a small machine or a personal machine, the overall height of the case 1 is shallow (about 40 m in depth) as described above.
m), the amount of the developer is smaller than that of a popular machine or a large machine. For this reason, when the image forming apparatus is installed, if the inclination occurs even at a slight angle, as shown in FIG. 19, the developer is unevenly distributed at one end of the stirring roller 4 because the amount of the developer is small. On the other hand, it becomes difficult for the developer to be conveyed, so that image formation cannot be performed properly.

More specifically, it is assumed that the height difference between the front side (front side) and the back side (rear side) of the image forming apparatus is about 3 mm, and a slight inclination occurs. In this case, the amount of the developer is largely biased toward the lower side of the inclined case 1, but the amount of the developer is decreased at the higher side, so that the developer is transported poorly. As a result, on the high side, a sufficient amount of developer is not supplied to the developing roller 2, and the output image is liable to be affected by uneven image density (referred to as a tiger mark).

As shown in FIGS. 20 and 21, a developer stirring member such as a stirring roller 4 conventionally used in a developing device has a spiral blade portion extending over the entire length of the rotating shaft 6 in the axial direction. 22 and 23, the structure and the shape are such that the same elliptical stirring blades 8 are arranged at equal intervals as shown in FIGS. In the figure, reference numeral 9 denotes a disk for preventing the developer from moving in the axial direction.

In such a developer stirring body, when the mounting angle of the blade with respect to the rotating shaft 6 is determined according to the rotating direction of the rotating shaft 6, the developer is always biased toward one end of the developing case. become. When the stirring roller 4 shown in FIG. 20 is rotated as indicated by an arrow, for example, the developer is transported from the front side (front side) indicated by F in the figure to the rear side (rear side) indicated by R. Further, in the stirring roller 4 shown in FIG. 22, a notch 10 is formed in a part of the back side of the stirring blade 8, and the developer is conveyed toward the back side. for that reason,
When such a stirring blade 8 is provided in the developing device, it is necessary to mount the stirring blade 8 at an angle so that the rear side is higher than the front side. Here, when the image forming apparatus is installed at an angle, if the rear side of the developing device is high and the front side is low, the developer is conveyed from the front side to the rear side, so that the developing agent is developed over almost the entire area in the axial direction. The developer is dispersed, so that the developer can be sufficiently supplied to the developing roller 2, and there is no particular problem. However, if the developing device is inclined so as to be lower on the rear side and higher on the front side while the configuration of the stirring roller 4 is kept as it is, the developer is unevenly distributed only on the rear side. The occurrence of density unevenness becomes more remarkable, and the quality of the formed image is extremely deteriorated.

In the developing device (1) described above, the developer can be dispersed in a normal arrangement. However, when the developing device is inclined, the developer cannot be dispersed well. On the other hand, in the developing device of (2), the developer is prevented from staying in the vicinity of the screw bearing, and the developer cannot be satisfactorily dispersed in the inclined developing device.

In the developing device disclosed in JP-A-5-72891 and the developing device disclosed in JP-A-7-175306, a partition wall is provided between a plurality of stirring rollers, and a photosensitive member is provided. After the developer is conveyed from both ends in the axial direction to the center by the stirring roller far from
The developer is transferred to an agitating roller facing the photoreceptor from an opening formed in the partition wall, and is supplied to the developing roller while being transported from the center toward both ends by the agitating roller. However, even in such a developing device, when the image forming apparatus is installed at an angle, the developer may not be sufficiently transferred between the stirring rollers due to the presence of the partition wall, and the amount of the developer may be small. It may be unevenly distributed.

In view of the above, the present invention eliminates the influence of the installation state of the image forming apparatus, in particular, the influence of the inclination of the installation place, and distributes the developer evenly over the entire area in the developing case to develop the image. It is an object of the present invention to provide a developing device capable of preventing a shortage of a developer and a conveyance failure and stably supplying a sufficient amount of a developer to a developing roller.

[0015]

Means for Solving the Problems According to the present invention, there is provided a developer stirring device which is rotatably mounted in a case and which is arranged in parallel with a developer carrying member. It can be conveyed toward. Thereby, when the image forming apparatus is installed at an angle,
Although the developer is unevenly distributed on one side in the axial direction in the case, the developer can be spread over the entire axial direction by the above-described developer agitator, and the developer is stably supplied to the developer carrier. It is possible to do.

Further, when another second developer agitator is arranged in parallel with the developer agitator, the second developer agitator moves the developer in the conveying direction from both ends toward the center. Keep it. The developer is transported from the center in the axial direction to both ends by the developer agitator close to the developer carrier, and the developer is returned to the center by the second developer agitator. A circulating flow is formed and the developer is evenly distributed.

The developer agitator includes a rotating shaft having a plurality of elliptical blades mounted thereon, a rotating shaft having a spiral blade portion mounted thereon, and a cylinder having a meshed peripheral surface. Although there are blade-shaped blades and the like, each of them has a structure in which a plurality of blades are attached in parallel in a state of being inclined with respect to the rotation axis. Therefore, as means for transporting the developer in the above-described direction, a notch is formed in a part of the elliptical blade, and the position of the notch is shifted by 180 degrees between one side in the axial direction and the other side, or The blades are formed in a semicircular shape, and are arranged so as to be shifted by 180 degrees on one side and the other side in the axial direction, or the inclination of the blades is reversed on the left and right sides in the axial direction. As a result, the developer can be transported to the end in the axial direction. Also, by making the interval between the adjacent blades wider at the central portion in the axial direction and narrower at both end portions, the conveying force of the developer toward the end portion in the axial direction is increased.

By the way, when the developer is conveyed toward both ends in the axial direction in the case, the pressure of the developer increases near the bearing portion which rotatably supports the developer stirring member.
It is preferable to reduce the developer conveying force at both ends. Therefore, as means for reducing the conveying force at both ends from the center, the inclination of the blades at both ends is reversed from that at the center, or the rotation radius of the blades at both ends is smaller than the rotation radius at the center. This is to provide a sub-transporting unit that is small.

Here, the developer is conveyed from the end in the axial direction toward the center by the sub-conveying unit. If the conveying force of the developer becomes excessive, the amount of the developer at the end in the case becomes insufficient. Therefore, it is preferable that the transporting force of the developer in the sub-transporting portions at both ends is set to be smaller than the transporting force in the main transporting portion in the central portion. As a result, the developer amount is kept balanced in the axial direction while the pressure rise near the side wall of the case is reduced.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) The construction of a developing device of this embodiment is basically the same as that shown in FIG. 16 of the related art. A plurality of agitating rollers 4 and 5 serving as an agent agitating body are rotatably provided in the case 1, and the rotation direction of the developing roller 2 and the agitating roller 4 disposed closest to the developing roller 2 are set in the same direction. I have. Although two stirring rollers are provided,
It is not particularly limited to this, but may be one. The number of agitating rollers is often one in a developing device used in an image forming apparatus for personal use, but is two in a developing device used in a popular machine or a large machine.
Often books. Since this is related to the amount of the developer in the developing device, the number of the stirring rollers does not particularly have a great effect on the stirring of the developer.

Here, in the developing device according to the present embodiment, as shown in FIG. 1, the flow direction of the developer conveyed by the stirring roller 4 arranged at least closest to the developing roller 2 is changed in the axial direction. In contrast, they are directed from the center to both ends. As a result, as shown in FIG. 2, even if the developing device is inclined, the rotation of the stirring roller 4 conveys the developer toward the higher end, and the developer contacts almost the entire surface of the stirring roller 4. As a result, the developer can be reliably and uniformly supplied to the developing roller 2.
The configuration of the stirring roller 4 for causing the flow direction of the developer to flow from the central portion in the axial direction to both ends as described above includes the following configuration.

First, as shown in FIG.
Has a structure in which a plurality of elliptical stirring blades 8 are attached to the rotating shaft 6 at a predetermined inclination angle and at regular intervals, and the position of the notch 10 formed in the stirring blade 8 is defined by the center in the axial direction. Is set to a point-symmetric position. That is, in the stirring blade 8 from the center to the front side, the notch 10 is formed in a part on the front side of the stirring blade 8, and in the stirring blade 8 from the center to the back side, the notch 10 is formed in a part on the back side of the stirring blade 8. At a position shifted by 180 degrees.

As described above, even if there is no particular change in the mounting state of the stirring blade 8, if the position of the notch 10 is set to a point symmetrical position with respect to the center in the axial direction, the stirring at the front side will be described. The blade 8 conveys the developer toward the front side, and the stirring blade 8 on the back side conveys the developer toward the back side. The stirring roller 4 arranged closest to the developing roller 2 Can transport the developer from the center to both ends as shown in FIG.

Alternatively, only the shape of the stirring blade 8 may be changed at the center in the axial direction without changing the inclination angle. That is, as shown in FIG. 4, the stirring blade 8 is formed in a substantially semicircular shape, and its arrangement is, for example, attached to the lower half with respect to the rotary shaft 6 on the front side at a constant interval, and fixed to the upper half on the rear side. Attach at intervals and give a 180 degree phase difference. Even in this case, the stirring roller 4 in which the notch 10 is formed
The developer can be conveyed in the same manner as described above.

In another embodiment of the stirring roller 4, the blade shape is line-symmetric with respect to the center in the axial direction. That is, as shown in FIG. 5, the inclination angle of the elliptical stirring blade 8 is different between the front side and the back side with respect to the center in the axial direction. Further, as shown in FIG. 6, a stirring roller 4 having a structure in which a spiral blade 7 is attached to a rotating shaft 6.
In this case, the winding direction of the blade 7 is different between the front side and the back side with respect to the center in the axial direction. In addition, the blade portion 7 is formed by integrally and continuously forming a plurality of parallel blades. As shown in FIG. 7, the circumferential surface of the cylindrical stirring roller 4 is a blade portion 11 having a mesh structure.
Is composed of a plurality of parallel blades 12 forming a mesh, and the winding direction of each blade 12 is different between the front side and the back side with respect to the center in the axial direction.

Even if the blades attached to the stirring roller 4 are arranged in line symmetry as described above, the blades on the front side convey the developer toward the front side, and the blades on the back side use the developer. Is transported toward the rear side, and the stirring roller 4 disposed closest to the developing roller 2 can transport the developer from the center to both ends as shown in FIG.

FIG. 8 shows another embodiment of the stirring roller 4. In the stirring roller 4, a plurality of elliptical stirring blades 8 are attached to the rotating shaft 6 at a predetermined inclination angle, but the attachment intervals of the stirring blades 8 differ in the axial direction. In other words, the distance A is constant at the center, but is constant B (<A) at both ends, and is set to be narrower at both ends than at the center. Also,
As shown in FIG. 9, the mounting interval of the stirring blades 8 may be gradually narrowed from the center toward both ends. Further, as shown in FIG. 10, in the blade portion 11 having a mesh structure, the mesh interval may be narrower at both end portions than at the center portion.

As described above, if the interval between the blades at the central portion is the largest, the interval between the blades becomes smaller toward the both ends, and the interval becomes the narrowest at both ends, the axial ends are adjacent to each other. The developer is easily held between the blades, so that the conveying force at both ends increases, and a sufficient amount of developer is supplied to the end of the developing roller where the amount of developer tends to be insufficient. can do.

In the stirring roller 4, the notch 10 of the stirring blade 8 is not described, but it is needless to say that the notch 10 can be appropriately provided. Further, the position where the notch 10 is provided is not particularly limited.

With the agitating roller 4 having the above-described configuration, when the image forming apparatus is installed at an angle, the lower end of the developing apparatus case 1 is affected by the difference in elevation. Even if the developer is unevenly distributed and the developer tends to be insufficient at the higher end, the transport direction of the developer can be opposite to each other in the axial direction, or the transport force can be increased toward the end. . As a result, the developer is fed to the end where the developer is insufficient by the stirring roller 4, so that a sufficient amount of the developer can be supplied over the entire axial direction of the developing roller 2. In addition, since the rotation direction of the stirring roller 4 disposed closest to the development roller 2 is the same as the rotation direction of the development roller 2, a sufficient amount of developer is fed to the development roller 2 and the photosensitive member Insufficiency in the amount of developer supplied to the developing area can be prevented.

Therefore, regardless of the installation state of the image forming apparatus, the developer in the case 1 spreads in the entire axial direction, the balance of the developer is maintained uniformly, and the developer is stably supplied to the developing roller 2. This makes it possible to supply the developer, thereby improving the developer transfer margin, suppressing the occurrence of developer transfer failure, and forming an image of stable image quality.

(Second Embodiment) The developer is transported toward both ends in the axial direction by the stirring roller 4 in the above embodiment. Therefore, there is a possibility that the developer may be excessively unevenly retained near the bearing of the stirring roller 4 and the sealing member in the case 1. Therefore, the bearing and the sealing member are buried in the accumulated developer, and the pressure by the developer increases, so that the developer enters the bearing and the sealing member. As a result, the fixing of the rotating shaft 6 and the stirring roller 4
There is a possibility that the rotation torque of the motor may increase.

Therefore, in order to avoid the above-mentioned problems, it is only necessary to suppress the developer from being unevenly distributed and staying at both ends. In the present embodiment, in order to alleviate a rise in the pressure of the developer due to the concentration of the developer near the bearing of the case 1, the agitating roller 4 is disposed at both ends of the agitating roller 4 disposed closest to the developing roller 2. A transport unit 15 is provided. Here, it is preferable that the conveying force of the developer by the sub-conveying section 15 is set to be smaller than the conveying force at the central portion of the stirring roller 4. The configuration of the stirring roller 4 having such a sub-transporting section 15 is not particularly limited, but may include, for example, the following configuration.

As shown in FIG. 11, in the stirring roller 4 provided with the blade portions 11 having the mesh structure shown in FIG. I do. The central portion becomes the main transport section 16 that transports the developer toward both ends. The transport direction of the sub-transport section 15 is opposite to that of the main transport section 16, and the stirring roller 4 transports the developer from the center to both ends, but transports the developer toward the center at both end portions. That means
At both ends, the developer conveyance force is weakened.
Here, the stirring roller 4 shown in FIG. 7 has been described, but in the stirring roller 4 shown in FIGS. 5 and 6, the inclination angle of the stirring blade 8 at both ends or the winding direction of the blade of the blade portion 7 is changed. Even if reversed, the same operation and effect can be obtained.

As shown in FIG. 12, in the stirring roller 4 provided with the mesh structure blade 11 shown in FIG.
The outer diameter D of the blade 12 at both ends is changed to the outer diameter C at the center.
(> D), which is referred to as a sub-transport section 15. The outer diameter of the blades 12 may be gradually reduced from the center to both ends. Alternatively, a structure in which blades 12 having different outer diameters are combined with small-diameter blades 12 at both end portions may be used. Therefore, in the stirring roller 4, the sub-conveying section 1
The transfer force of the developer in the radial direction (radial direction) at 5 is smaller than the transfer force of the radial direction at the main transfer portion 16 at the central portion. Here, the stirring roller 4 shown in FIG. 7 has been described. However, in the stirring roller 4 shown in FIGS. 5 and 6, even if the size of the stirring blade 8 at both ends or the blade of the blade portion 7 is reduced. A similar effect can be obtained.

As described above, the sub-transport section 1 is
By providing 5, even if the developer is conveyed from the center to both ends, the developer conveyance force is weakened at both end portions, so that the developer can be prevented from being concentrated near the bearing of the case 1, The pressure rise of the developer can be reduced.
Therefore, the developer is not excessively unevenly distributed in the vicinity of the bearing or the sealing member of the stirring roller 4 in the case 1 and stays there. Thus, problems such as the fixation of the rotating shaft 6 and an increase in the rotating torque of the stirring roller 4 occur. No longer.

Incidentally, the developer conveying force in the radial direction (radial direction) of the main conveying section 16 of the stirring roller 4 is set to be larger than the developer conveying force in the axial direction (thrust direction), and the sub conveying section It is highly preferable that the developer transfer force in the radial direction at 15 is set smaller than the developer transfer force in the axial direction.

This is because the sub-transporting section 15 is provided for the purpose of alleviating the pressure rise due to the concentration of the developer near the side wall surface of the case 1, whereas the main transporting section 16 is provided to the developing roller 2. This is because it is provided for the purpose of stably supplying the developer. That is, since the agitating roller 4 is disposed closest to the developing roller 2, when the transporting force in the radial direction of the sub-transporting portion 15 becomes excessive, the developer and the developer are removed from the gap between the developing roller 2 and the side wall of the case 1. Toner spouts,
May cause leakage. Therefore, the developer is transported mainly by the sub-transport section 15 in the axial direction, and is transported in the radial direction. On the other hand, since the main transport section 16 is required to stably supply the developer to the developing roller 2, the transport of the developer in the radial direction is mainly performed, and the transport of the developer in the axial direction is dependent. Thereby, the balance of the developer amount in the axial direction in the case 1 can be maintained uniformly.

(Third Embodiment) The developing device of each of the above embodiments is provided with a plurality of stirring rollers 4 and 5,
The first stirring roller 4 closest to the developing roller 2 is configured to convey the developer from the center to both ends in the axial direction. As shown in FIG. 13, the second stirring roller 5 disposed in parallel with the first stirring roller 4 at a position far from the developing roller 2 transports the developer from both ends toward the center. I do.

More specifically, since the second stirring roller 5 is driven to rotate in the same direction as the first stirring roller 4, the configuration of the blades is exactly opposite to the configuration of the blades of the first stirring roller 4. I just need. For example, the inclination angle of the stirring blade 8 is reversed, or the winding direction of the spiral blade 7 or the winding direction of the mesh-structured blade 11 is reversed. Further, if the rotation direction of the second stirring roller 5 is opposite to the rotation direction of the first stirring roller 4, the blade may have the same configuration as that of the first stirring roller 4.

By defining the direction in which the developer is transported by each of the stirring rollers 4 and 5, the first stirring roller 4 transports the developer from the center to both ends in the axial direction and the second stirring roller. At 5, the developer is transported so as to return to the center. Therefore, the developer circulates in the case 1,
A circulating developer flow will be formed,
The distribution distribution of the developer in the case 1 can be kept uniform, and image unevenness does not occur and the image quality can be improved.

(Embodiment) The results of examining the agitating property of the developer in the axial direction (thrust direction) between the improved developing device employing the above-described agitating rollers and the conventional existing developing device are shown. It is shown in FIG. In the case of the improved type shown by a circle in the figure, if the stirring time exceeds 5 minutes, the toner concentration on both the driving side and the driven side becomes constant at 3.5%. On the other hand, in the conventional case shown by a diamond, if the stirring time does not exceed 15 minutes, the toner concentration on both the driving side and the driven side will not be constant. Therefore, the developing device according to the present invention is more excellent in the axial stirring property. The driving side corresponds to the back side, and the driven side corresponds to the front side.

Further, the occurrence of white spots due to poor conveyance when the image forming apparatus was installed at an angle was examined. As shown in FIG. 15, in the conventional case, the conveyance of the developer occurs at an inclination of 2 ° or more, and particularly, the width of self-extraction is 5 °.
Up to 15 mm with the inclination of. On the other hand, in the improved developing device according to the present invention, if the inclination angle does not reach 3 °, no conveyance failure occurs, and even if the inclination angle is 5 °, only a maximum of about 6 mm self-removal occurs. Therefore, the developing device according to the present invention can obtain very excellent effects.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. For example, the blades of the stirring roller need not be symmetrical about the center in the axial direction, but may be shifted to one end, and more developer can be conveyed to one end than the other end. In addition, the second stirring roller may have the same configuration as the first stirring roller, and may convey the developer from the center in the axial direction to both ends. In this case, the conveying force of the developer of the second stirring roller is set to be smaller than the conveying force of the first stirring roller.

[0045]

As is apparent from the above description, according to the present invention, in consideration of the case where the image forming apparatus is installed at an angle, the developer is developed so as to spread over the entire axial direction in the case. Since the developer agitator forms a flow of the developer from the center in the axial direction to both ends, the developer is prevented from being unevenly distributed at the lower end in the case, and the developer is also provided at the higher end. Can be conveyed, and the shortage of the developer can be prevented, and the poor conveyance of the developer can be prevented. Therefore, the developer can be sufficiently and stably supplied to the developer carrying member by eliminating the influence of the inclination of the image forming apparatus, and the image quality can be improved irrespective of the installation state.

When the second developer agitator is disposed in parallel with the developer agitator, the developer is transported by the second developer agitator from both ends toward the center. A part of the developer conveyed to both ends returns to the central portion and circulates again, so that the developer can be dispersed in the case with good balance.

In addition, if a sub-transporting portion having a weak developer transporting force is provided at both ends of the developer stirring member, the pressure of the developer at the edge generated when the developer is transported toward both ends is reduced. The rise can be alleviated, and the adverse effect due to the increase in pressure can be eliminated, so that a decrease in the carrying capacity of the developer stirring body can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow of a developer in a developing device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating behavior of a developer due to conveyance of a stirring roller when the developing device is installed at an angle.

FIG. 3 is a perspective view showing one embodiment of a stirring roller.

FIG. 4 is a front view showing one embodiment of a stirring roller.

FIG. 5 is a front view showing one embodiment of a stirring roller.

FIG. 6 is a front view showing one embodiment of a stirring roller.

FIG. 7 is a front view showing one embodiment of a stirring roller.

FIG. 8 is a front view showing one embodiment of a stirring roller.

FIG. 9 is a front view showing one embodiment of a stirring roller.

FIG. 10 is a front view showing one embodiment of a stirring roller.

FIG. 11 is a front view showing an embodiment of a stirring roller according to the second embodiment.

FIG. 12 is a front view showing one embodiment of the stirring roller.

FIG. 13 is a diagram illustrating a flow of a developer in a developing device according to a third embodiment.

FIG. 14 is a diagram showing the agitating property of the developer in the axial direction in the developing device of the present invention.

FIG. 15 is a diagram illustrating an influence of the inclination of the image forming apparatus on a developer conveyance failure.

FIG. 16 is a configuration diagram of a conventional developing device.

FIG. 17 is an exploded perspective view of a developing device.

FIG. 18 is a diagram illustrating a state of a stirring roller with respect to a developer when an image forming apparatus such as a large machine is installed at an angle.

FIG. 19 is a diagram illustrating a state of a stirring roller with respect to a developer when an image forming apparatus such as a small machine is installed at an angle.

FIG. 20 is a front view showing one embodiment of a conventional stirring roller.

FIG. 21 is a front view showing an embodiment of a conventional stirring roller.

FIG. 22 is a perspective view showing one embodiment of a conventional stirring roller.

FIG. 23 is a front view showing one embodiment of a conventional stirring roller.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Case 2 Developing roller 4, 5 Stirring roller 6 Rotating shaft 7 Spiral blade 8 Stirring blade 10 Notch 11 Mesh-shaped blade 15 Sub-transport unit 16 Main transport unit

Claims (9)

[Claims] 1. A case accommodating a developer is disposed opposite to a photoreceptor, a developer carrier disposed in parallel with the photoreceptor and supplying the developer to the photoreceptor, and a developer loaded in the axial direction. A developer agitator that feeds the developer to the developer carrier while being conveyed is rotatably provided, and the developer agitator is provided with a plurality of blades that are attached to the rotation shaft at intervals in the axial direction. Each blade is formed in an elliptical shape having a notch in a part and provided in parallel in an inclined state, and the notches of a plurality of blades at one end in the axial direction are the remaining blades at the other end. Wherein the developer is conveyed toward both ends in the axial direction by rotation of the developer stirring member. 2. A case accommodating a developer is disposed opposite to a photoreceptor. The case has a developer carrier disposed in parallel with the photoreceptor and supplying the developer to the photoreceptor. A developer agitator that feeds the developer to the developer carrier while being conveyed is rotatably provided, and the developer agitator is provided with a plurality of blades that are attached to the rotation shaft at intervals in the axial direction. Each blade is formed in a substantially semicircular shape and is provided in parallel in an inclined state, and a plurality of blades on one end side in the axial direction are shifted by 180 degrees from the remaining blades on the other end side. Wherein the developer is conveyed toward both axial ends by rotation of the developer agitator. 3. A case accommodating a developer is disposed opposite to the photoreceptor. The case has a developer carrier disposed in parallel with the photoreceptor and supplying the developer to the photoreceptor. A developer agitator for feeding the developer to the developer carrier while being conveyed is rotatably mounted on the developer agitator, and the developer agitator is attached at an interval parallel to and inclined with respect to the rotation axis. Having a plurality of blades, the distance between the blades at both ends in the axial direction is narrower than the distance between the blades at the center, and the developer is conveyed toward both ends in the axial direction by rotation of the developer stirring body. A developing device. 4. A case accommodating a developer is disposed opposite to the photoconductor, and a developer carrier arranged in parallel with the photoconductor and supplying the developer to the photoconductor is provided on the case. A developer agitator for feeding the developer to the developer carrier while being conveyed is rotatably mounted on the developer agitator, and the developer agitator is attached at an interval parallel to and inclined with respect to the rotation axis. It has a plurality of blades, and the interval between the blades is set so as to gradually decrease from the central portion in the axial direction toward both ends, and the developer is conveyed toward both ends in the axial direction by rotation of the developer stirring body. A developing device. 5. A case in which a second developer agitator is rotatably mounted in a case at a position farther from the photosensitive member than the developer agitator and in parallel with the case, wherein the second developer agitator is provided with the developer agitator. The developing device according to any one of claims 1 to 4, wherein the developing device is configured to rotate in the same direction as the stirrer so that the developer is conveyed from both ends toward the center. 6. A sub-conveying unit having a blade inclined at a different angle from the central blade at both ends of the developer agitator. 3. The developing device according to claim 1. 7. A sub-conveying section having a rotation radius of a blade different from a rotation radius of a blade at a central portion is provided at both end sides of the developer stirring body. 3. The developing device according to claim 1. 8. The developing device according to claim 6, wherein the developer transporting force of the sub-transporting section is set smaller than the developer transporting force at the central portion. 9. The developer conveying force in the radial direction of the blade at the central portion is set to be larger than the developer conveying force in the axial direction, and the developer conveying force in the radial direction of the sub-transporting portion is set in the axial direction. The developing device according to claim 6, wherein the developer conveying force is set to be smaller than the developer conveying force.