JPH0996957A - Developer stirring mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly and quickly attain uniform stirring by providing a cylindrical partition space for partitioning the flow passages of developer carried by first and second stirring members and plural opening parts from which the developer of each flow passage can flow in and out, in a partition space forming body. SOLUTION: The plural opening parts 121 are formed in the surface of a cylinder 12 and allow the developer to flow into/from the cylinder 12. The opening parts are formed larger in size, as the opening parts are nearer to an end part, to prevent the bias of the developer. Further, as the fixed cylinder 12, a rotary body can be used. As the flow of the developer, the developer existing outside the cylinder 12 is moved to the right (in the figure), while being rotated by the rotation of an outer blade 11. When the developer comes to the opening parts of the fixed cylinder 12, the developer flows in and then, is carried in an opposite direction and when the developer comes to the opening parts 121, the developer is discharged. Thus, such processes are repeated to stir the developer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer stirring mechanism arranged in a developer container in a toner container or a developing container.

[0002]

2. Description of the Related Art A developing device using a two-component developer composed of a carrier formed of magnetic powder such as ferrite and a toner formed of a non-magnetic material such as resin or carbon has been known. The mixing and stirring mechanism of the developer in the developing device of the kind is generally a screw type stirring member in which a screw is spirally fixed around a rotating shaft mounted rotatably in a developing container, and the rotating shaft is , A stirring member (single-vibration stirring member) in which a large number of blades inclined in parallel to the axial direction are continuously provided, and is replenished from the toner container side into a developing container in which the carrier and toner are stored. It is designed to maintain uniform concentration distribution of the toner and carrier in the container while mixing and stirring the toner with the stirring member.

In such an apparatus, in recent years, the particle size of the carrier has been reduced in order to improve the charging efficiency, and in recent years, instead of the carrier formed of magnetic powder such as ferrite, the carrier surface has been made uniform and oxidized. A so-called resin carrier in which the surface of the magnetic core material is coated with a resin is often used for the purpose of preventing, scratching the surface of the photoreceptor by the carrier, preventing wear, and controlling charge.

However, when the small-diameter carrier or resin carrier is used as described above, the difference in specific gravity between the toner and the carrier becomes small, and as a result, the fluidity is significantly lowered.

When such a developer is agitated and mixed by the screw type or single vibration type agitating member, since the pressing surface of the blade body facing the developer is a surface orthogonal to the rotation direction, the blade body is Following the rotation of, the developer rotates in a ring shape while clinging to the blade surface, and smooth stirring cannot be performed.

If the blades are made obtuse, the clinging is eliminated, but the moving speed of the developer is slowed down, and the stirring speed is delayed.

If the pitch of the blades is reduced in order to prevent such a defect, the developer is clogged between the adjacent blades.

On the other hand, also in the screw blade, since the screw only rotates so as to cut the inside of the accumulated portion of the developer in powdery form, the developer sandwiched between the screw pitches simply moves in the rotation axis direction. Therefore, smooth stirring is still difficult. Further, since the stirring members are arranged on the rotating shaft in a predetermined direction in any of the stirring members, the developer is conveyed in one direction, and the developer is not attached to the side wall of the casing at the end of the developer conveying direction. Clogging, an increase in drive torque, and leakage of the developer from the casing bearing portion tend to cause contamination inside the machine.

In order to solve such a drawback, there is a technique in which the inclination direction of the blade body or the spiral direction of the screw blade is set in the opposite direction with the center position of the rotation axis sandwiched therebetween. Are accumulated, the developer on both ends is insufficient, and the toner density in that portion is reduced.

For this reason, generally, two stirring shafts whose rotation directions are set in opposite directions are provided side by side, and a uniform stirring is performed while the developer is moved forward and backward by each stirring shaft ( JP-A-62-21679 and JP-A-1-123270) also exist, but since such a technique has a configuration in which two or more stirring members are arranged in parallel, the size of the container and the device tends to increase.

In order to solve such a drawback, a bucket shaft for supplying toner to the developing sleeve side is provided with an agitation shaft in which a large number of blade members inclined with respect to a rotating shaft are connected in the axial direction, and the agitation shaft is provided. Among these blade bodies, there is proposed a technology (Japanese Patent Laid-Open No. 62-291679) in which the blade body on the end side is inclined in the opposite direction.

[0012]

However, in such a technique, since the developer that has moved forward by the large number of blades is made to face the backward movement by the reverse blades, the backward movement portion thereof has a structure. Not only does the developer collide with each other to make smooth stirring difficult, but it also increases the axial torque.

In view of the above-mentioned drawbacks of the prior art, the present invention is to provide a developer stirring mechanism which enables smooth and rapid uniform stirring even in the case of a developer containing a small particle carrier. It is another object of the present invention to provide a developer stirring mechanism that allows smooth and quick uniform stirring without causing the developer to shift or the axial torque from increasing.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a developer agitation mechanism configured to mix and agitate a developer by rotating a plurality of agitating members. A second stirring member, and a cylindrical partition space body for partitioning each flow path of the developer conveyed by the first and second stirring members, wherein each partition space forming body flows through each flow path. A plurality of openings are provided so that the developer can enter and exit.

According to the structure of the present invention, the partition space forming body (cylindrical) is used to separate the flow path of the developer, and the developer conveyed from the outside of the partition space forming body is sequentially passed through the plurality of openings. The developer existing outside is taken in the inside in the direction of the rotation axis, while the developer carried from the inside is discharged while being sequentially discharged from a plurality of openings. Is conveyed in the opposite direction, so that the developer can be finely replaced.

Further, the partition space forming body may be fixed. The partition space forming body may be fixed. As a result, the position of the opening is fixed so that the inside and outside of the developer can be kept in and out, and the opening position of the partition space forming member can be adjusted according to the uneven stirring of the developer to determine the position where uniform stirring is possible.

The rotation of the first stirring member and the rotation of the second stirring member may be coaxial, and the rotation directions may be the same. As a result, the size of the device is reduced and only one means of rotation drive is required, which leads to cost reduction.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be illustratively described in detail with reference to the drawings. FIG. 1 shows an internal structure of a developing device according to an embodiment of the present invention, and a mechanical structure thereof will be briefly described. 1 is a developing container containing a developer 8 in which a carrier and a toner are adjusted at a predetermined concentration ratio. so,
A mag roll (magnet assembly) that faces the photosensitive drum 3 rotating in the arrow direction D and is rotatably supported in the arrow direction S.
A developing sleeve 4 containing 4a is arranged, and a cylindrical stirring member 10 is arranged on the inner side of the developing container 1 in parallel with the axis of the magnet assembly 4a.

Then, the toner container 2 is detachably mounted from the developing device through the slit opening 2a on the wall surface of the developing container 1 opposite to the developing sleeve 4 facing the stirring member 10 and the sponge is formed in the slit opening 2a. A toner replenishing roller 5 enclosing the replenishing roller is rotatably attached, and a DC motor (not shown) connected to the replenishing roller 5 based on a T / C detection signal from a toner concentration detection sensor 6 provided at the bottom of the developing container 1. By controlling the rotation of the toner, the toner replenishment amount can be arbitrarily adjusted. Incidentally, 7 is the developing sleeve 4.
This is a doctor blade for regulating the layer thickness of the developer 8 magnetically held on the upper side.

As shown in FIGS. 2 and 3, the stirring member 10 which is the main part of the present invention has an outer blade (first stirring member) 11 on the outer side and a developer inside the outer blade 11. A cylinder (partition space forming body) 12 for partitioning the flow of 8 and a screw (second stirring member) 13 are arranged inside the cylinder 12.

Both ends of the outer blade 11 are fixed by the flanges 111, and the outer blade 11 extending in the axial direction is formed to be slightly inclined with respect to the axial direction. The external developer 8 is configured to be movable in the uniaxial direction. The outer blade 11 is configured coaxially with the rotating shaft 101 of the screw 13, and one end of the rotating shaft 101 is configured to be rotatable by a bearing 103 of the cylinder 12. The other end of the rotary shaft 101 is connected to a drive device (not shown), and the cylinder 12 is rotated by the rotation of the drive device.
The screw 13 arranged inside and the outer blade 11 rotate integrally. As a result, the outer blades 11 are formed so as to be conveyed in the opposite direction.

The cylinder 2 is fixed to the housing of the apparatus, both ends of the cylinder 12 are sealed, and one end is connected to one side of the outer blade 11 via a bearing 102. The other end is connected to the other side surface of the cylinder 12 via the bearing 104.

A plurality of openings 121 are formed on the surface of the cylinder 12 to allow the inside and outside of the cylinder 12 to come in and out. However, it is preferable that the size of the opening be larger toward the end in order to prevent the deviation of the agent. Further, although the fixed cylinder 12 has been described in the present embodiment, the present invention is not limited to this and may be a rotating body.

As for the flow of the developer 8, the developer 8 existing outside the cylindrical body 12 moves while rotating to the right in the figure by the rotation of the outer blade 11. At this time, when it comes over the opening of the fixed cylinder 12, it enters the inside, and the developer that enters the inside is conveyed in the opposite direction and is discharged when it reaches the opening 121, and these things are repeated and stirred. Will be.

[0025]

As described above, according to the present invention, even a developer having low fluidity or small particles can be stirred and mixed smoothly and in a short time, and singularization and weight saving can be achieved during the constitution. It

Further, according to the present invention, it is possible to smoothly and quickly agitate the developer without causing the deviation of the developer and the increase of the axial torque.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an internal configuration of a developing device according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing a configuration of a vertical cross section of the stirring member of the present invention.

FIG. 3 is a schematic explanatory view showing a configuration of a cross section of the stirring member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing container 4a Roll-shaped magnet assembly 11 Outer blade (1st stirring member) 12 Cylinder (2nd stirring member) 13 Screw

Claims (3)

[Claims] 1. A developer agitation mechanism configured to mix and agitate a developer by rotating a plurality of agitating members; first and second agitating members for conveying the developer in different rotational axis directions, And a cylindrical partition space body that partitions each flow path of the developer conveyed by the first and second stirring members, and a plurality of the developer that can flow in and out of each flow path in the partition space forming body A developer stirring mechanism characterized by having an opening. 2. The developer stirring mechanism according to claim 1, wherein the partition space forming member is fixed to a casing of the apparatus. 3. The developer stirring mechanism according to claim 1, wherein the first stirring member and the second stirring member are rotated coaxially and the rotation directions are the same.