JPH10171224A - Stirring member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stirring member for preventing powder from being flocculated and fixed on the circumference of a rotary shaft. SOLUTION: A stirring member 10 is constituted of the rotary shaft 12 and two helical members 14 and 16 whose winding directions are different. The rotary shaft 12 is coated with the helical members 14 and 16, in such a manner that at least part of the helical members 14 and 16 are overlapped with each other. Further, one end of one helical member 14 is fixed on one end part of the rotary shaft and one end of the other helical member 16 is fixed on the other end part of the rotary shaft. Thus, in the overlapped region 34 of the helical members 14 and 16, a carrying property in a rotational direction is obtained and in the nonoverlapped region 42, the carrying property in an axial direction is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member for stirring powder such as a developer, and more particularly to a stirring member which can be suitably used in a developing device of an image forming apparatus using a powder developer.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus such as a copying machine or a printer, a developer or a powder developer comprising a toner and a carrier is stored in a developer storage chamber in a developing device.
Further, usually, the developing device has a built-in developer stirring member to prevent the developer from aggregating.

[0003] As the developer stirring member, a member provided with a plurality of blades around a rotation shaft drivingly connected to a motor is widely known. Japanese Utility Model Laid-Open No. 5-17658 discloses a rotating shaft and two helical members having different winding directions. These helical members are arranged on both sides of the rotating shaft at an interval. A stirring member having both ends fixed to a rotating shaft is disclosed. Further, Japanese Patent Application Laid-Open No. 4-124261 discloses a helical toner feeder wound in opposite directions around a central portion. Furthermore, Japanese Patent Application Laid-Open No. 4-59386
The publication discloses a rotating member in which one helical member is provided on a rotating shaft and both ends of the helical member are fixed to the rotating shaft.

[0004]

However, in a stirring member in which a blade member is merely provided on a rotating shaft, the developer is fixed around the rotating shaft and the blade member, and the fixed developer grows to increase the stirring efficiency. There is a problem of lowering. In addition, 5-1
No. 7658 and a stirring member disclosed in JP-A-4-1242.
The toner feeder disclosed in Japanese Patent Publication No. 61 merely moves the developer on both sides to the center, and has no function of positively transporting the developer in the rotation direction. Therefore, a member for that purpose must be separately provided. No. Further, Japanese Patent Application Laid-Open No. 4-53
The rotating member disclosed in Japanese Patent No. 986 conveys the developer only in one direction along the rotating shaft, and there is a problem that the developer is biased toward one end of the rotating shaft.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a stirring member which can prevent the developer from adhering to a rotating shaft or a peripheral wall thereof and can convey the developer not only in the axial direction but also in the rotating direction. The stirring member is constituted by a rotating shaft and two helical members having different winding directions, and these helical members are overlapped with each other at least in a part thereof, and are provided on the rotating shaft. Exterior, one helical member has one end fixed to one end of the rotating shaft,
The other helical member has one end fixed to the other end of the rotating shaft.

[0006]

In the above stirring member, each helical member is fixed to the end of the rotating shaft only at one end thereof, and the other end is free. Therefore, when the rotating shaft rotates, the helical member rotates while coming into contact with or separating from the rotating shaft, whereby powder (developer) attached to the rotating shaft is removed by the contact of the helical member. In addition, the stirring action of the helical member extends to the powder around the rotating shaft,
Agglomeration of the powder in that region is prevented.

In addition, in a region where the two helical members overlap each other, since these helical members are wound in different directions, the axial conveying operation of one helical member is performed in the opposite direction of the other helical member. It is erased by the directional transport action. However, in the overlapping area,
Since the helical members intersect with each other, this provides a transport effect in the direction of rotation. Further, if non-overlapping areas are provided on the fixed side of each helical member, the powder (developer) in these areas is fed to the overlapping areas.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a stirring member 10 of the present invention. As shown in FIG. 2, which is an exploded view of the stirring member 10, the rotating shaft 12 and the two helical members 1
4, 16 (for example, a helical spring).

The rotating shaft 12 has a gear portion 18 at one end and supports 20 and 22 at both ends.
The gear unit 18 is rotatably supported via a gear 2 and is connected to a drive system. In addition, the rotating shaft 12 may be formed of any of synthetic resin and metal, and the rotating shaft 12 may have an arbitrary cross-sectional shape such as a circle and a rectangle.

The winding directions of the helical members 14 and 16 are reversed, and the helical members 14 and 16 are respectively provided from both ends of the rotary shaft 12 and overlap with each other in the central region 34 except for regions 42 of a predetermined width at both ends. doing. Helical member ends 24 and 26 at both ends of the rotation shaft are fixed to both end fixing portions 28 and 30 of the rotation shaft 12, respectively.

When the stirring member constructed as described above is rotated in the direction of arrow 32, in the region (overlapping region) 34 where the helical members 14, 16 overlap, as shown in FIG. Axial transfer force (arrow 3
6) is offset by the axial conveying force (arrow 38) of the other helical member 16 which is moving in the opposite direction. However, since the helical members 14 and 16 intersect in the overlapping region 34, a conveying force (arrow 40) is generated in the rotation direction, that is, the direction orthogonal to the axial direction. On the other hand, a region (non-polymerized region) 4 where the helical members 14 and 16 on both sides of the rotating shaft are not superposed.
In No. 2, as shown in FIGS. 4 (a) and 4 (b), a conveying force (arrows 36, 38) toward the center is obtained, respectively.

A specific application example of the stirring member 10 will be described with reference to FIG. FIG. 5 shows a part of a developing device 52 for visualizing an electrostatic latent image formed on the surface of the photoconductor 50 with toner in an electrophotographic image forming apparatus such as a copying machine or a printer. The developing device 52 has a housing 54. The housing 54 contains a developing roller 56 facing the photoconductor 50. A toner supply chamber 58 is formed on the opposite side of the photoconductor 50 across the developing roller 56. In the toner supply chamber 58, a toner supply roller 60 is provided.
And a toner stirring member 62 disposed above the toner supply roller 60, and the above-described stirring member 10 is used as the toner stirring member 62. Developing roller 56
A blade 64, one end of which is fixed to the ceiling of the housing 54, extends between the toner agitating member 62 and the free end of the blade 64 in pressure contact with the outer peripheral surface of the developing roller 56. The toner supply chamber 58 communicates with a toner storage chamber 70 via a passage 66, and toner is supplied from the toner storage chamber 70 to the toner supply chamber 58.

In the developing device 52 configured as described above, the developing roller 56, the toner supply roller 60, and the toner stirring member 62 are drivingly connected to a motor (not shown). , 7
4. Rotate in 76 directions. Thereby, the toner supply chamber 5
In 8, the toner is stirred by the toner stirring member 62, and the toner stirred by the toner supply roller 60 is supplied to the developing roller 56. Then, the toner in contact with the outer peripheral surface of the developing roller 56 is transported in the direction of the arrow 72, and is held on the outer peripheral surface of the developing roller 56 by the blade pressing portion 78. Next, the toner that has passed through the blade pressing portion 78 is transferred to the photoconductor 5 by the opposing portion of the photoconductor 50 and the developing roller 56.
The electrostatic latent image on 0 is contacted and visualized. When the toner is consumed in this manner, an amount of toner corresponding to the consumed amount is supplied from the toner storage chamber 70 to the toner supply chamber 58 via the passage 66.

The helical members 14 and 16 of the toner stirring member 62 rotate together with the rotation of the rotating shaft 12 to pulverize and stir the toner in the toner supply chamber 58. At this time, one end of the helical members 14 and 16 is free, so that the helical members 14 and 16 freely move around the rotation shaft 12 and not only the area (inside) surrounded by the helical members 14 and 16 but also the toner around the helical members 14 and 16. Also pulverize and stir. Therefore, the stirring area of the toner stirring member 62 is significantly enlarged as compared with the conventional stirring member. At the same time, the helical members 14 and 16 also come into contact with the rotating shaft 12 and scrape off the toner attached to the rotating shaft 12.

In the overlapping region of the helical members 14 and 16, the toner stirring member 62 has a conveying property in the rotation direction, and not only stirs the toner but also removes the residual toner regulated by the blade pressing portion 78. Carry so that it is positively excluded. On the other hand, in the non-polymerized areas 42 of the helical members 14 and 16, the toner at both ends of the toner supply chamber 58 is transported toward the center (polymerized area 34), and
Is prevented from staying.

The width of the superposed area 34 and the non-superposed area 42;
That is, the length of the helical members 14 and 16 is
2 is determined based on the relationship with the image forming area or toner consumption area of the image forming apparatus in which the image forming apparatus 2 is built. For example, in the case of a copier,
In a type in which the center of the document is positioned with respect to the center of the document platen, the helical members 14 and 16 are so arranged that the overlap area matches the width of the most frequently used paper size. Determine the length.

The non-polymerized areas 4 on both sides of the stirring member 10
2 may have the same width (length in the axial direction) on the left and right,
The width of one non-polymerized region 34 may be longer than the width of the other non-polymerized region 34. Further, it is not essential that the non-overlapping area 34 is formed on both sides of the stirring member 10. The non-overlapping area 34 is configured such that a document is arranged or transported or a transfer sheet is transported with reference to a regulation wall along the optical system scanning direction of the image forming apparatus. In the image forming apparatus described above, the lengths of the helical members 14 and 16 may be different so that the non-overlapping region 34 is formed only on one end side of the stirring member 10.

Further, the helical members 14, 16 may be colored in different colors. In this case, it can be easily confirmed that the predetermined helical members 14 and 16 are arranged in a certain area. Furthermore, the helical members 14, 16 may have different diameters.

In addition, the stirring member of the present invention can be widely applied to devices other than the developing device as long as it is necessary to stir the powder.

[Brief description of the drawings]

FIG. 1 is a perspective view of a stirring member according to the present invention.

FIG. 2 is an exploded perspective view of a stirring member.

FIG. 3 is an enlarged front view of a polymerization region of a stirring member.

FIG. 4 is an enlarged front view of a non-polymerized region of the stirring member.

FIG. 5 is a partial sectional view of the developing device.

[Explanation of symbols]

10: stirring member, 12: rotating shaft, 14, 16: helical member.

Claims (1)

[Claims] 1. A helical member having a rotating shaft and two helical members having different winding directions is provided on the rotating shaft so that at least a part of the helical members overlaps each other, and one helical member rotates one end of the helical member. A stirring member fixed to one end of a shaft, and the other helical member having one end fixed to the other end of the rotating shaft.