JPH08185026A - Toner supply paddle - Google Patents

Abstract

PURPOSE: To reduce the variation in the density of a toner image on a photoreceptor by blocking toner moving action from one end to the other end of a toner supply paddle. CONSTITUTION: A supporting piece 6b supporting the back surface of an elastic piece 3 pressing toner in a toner container on the side opposite to a rotating direction is provided at the end of a supporting member 2 supporting the elastic piece 3 on a side not coupled with a driving mechanism. Thus, even when the supporting member 2 is somewhat twisted by the resistance of the toner received by the elastic piece 3, the back surface of the elastic piece 3 opposite to the rotating direction is supported at the end of the side where the rotation of the elastic piece 3 is lagged by the supporting piece 6b, so that the extent of the deformation of the elastic piece 3 by the pressure of the toner is made maximum at the center part of the elastic piece 3 and the toner moving action from one end to the other end of the elastic piece 3 is prevented, or a supporting wall supporting the elastic piece 3 and shaped so that the distance from the center of the rotation of the supporting member 2 becomes smaller from both ends toward the center part in order to deform the center part of the elastic piece 3 to the maximum is provided in the supporting member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner supply paddle used in a developing device for developing an electrostatic latent image formed on a photoconductor.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus for forming an image by an electrophotographic method such as a laser printer and a copying machine,
A developing device in which a toner supply paddle is rotatably provided in a toner container in which a developing roller is rotatably held, and the toner in the toner container is agitated and supplied to the developing roller by rotating the toner supply paddle. There is.

A toner supply paddle used in such a developing device is shown in FIG. The toner supply paddle 50 is formed by adhering an elastic piece 52 formed of a thin piece having elasticity to a rod-shaped support member 51 having a polygonal cross-sectional shape. Shafts 53 and 54 that are freely supported are formed.

[0004]

The support member 51 is provided with an arrow A.
When rotated in the direction, the pressure of the toner in the toner container is applied to the elastic piece 52, so that it is necessary to give a large rotation torque to the support member 51. However, since the conventional support member 51 is made of synthetic resin in order to reduce the cost and the weight, as shown in FIG. 8, the support member 51 has a shaft portion 53 to which a rotational force in the direction of arrow A is applied. It is twisted so that the rotation angle on the side of the shaft 54 becomes smaller than the rotation angle on the side. Therefore, the elastic piece 52 is also twisted such that the rotational movement of the other end on the shaft portion 54 side is delayed with respect to the one end on the shaft portion 53 side. The elastic piece 52 shown by a phantom line shows a state when the support member 51 is not twisted, and the elastic piece 52 shown by a solid line shows a state when the support member 51 is twisted. Although FIG. 8 is exaggerated for visual representation of the twisted state, when the elastic piece 52 is twisted like a blade of an axial fan, the rotation is delayed (arrow B direction). In addition, if the toner in the toner container moves from one end of the elastic piece 52 to the other end, and if the moving action is continuously performed, there is a problem that a difference in toner concentration occurs at both ends of the photoconductor.

[0005]

According to the first aspect of the present invention,
A rod-shaped support member made of synthetic resin, which is rotatably supported in a toner container in which toner is accommodated and one end of which is connected to a drive mechanism including a motor, and an axial direction of the support member which is formed by an elastic thin piece. Toner constituted by an elastic piece projecting in a direction orthogonal to and a supporting piece arranged at least at an end of the supporting member in a direction not connected to the driving mechanism and supporting a rear surface of the elastic piece on the rear side in the rotation direction. Supply paddle.

According to a second aspect of the present invention, a rod-shaped support member made of synthetic resin, which is rotatably supported inside a toner container in which toner is accommodated and has one end connected to a drive mechanism including a motor, has elasticity. An elastic piece formed of a thin piece and projecting in a direction orthogonal to the axial direction of the support member, and a shape in which the distance from the rotation center of the support member gradually decreases from both ends of the support member toward the central portion And a support wall that supports the back surface of the elastic piece on the rear side in the rotation direction, and the toner supply paddle.

[0007]

According to the first aspect of the invention, even if the elastic member receives the resistance of the toner and the supporting member is twisted to some extent, the rear surface on the rear side in the rotational direction at the end in the direction in which the rotational movement of the elastic piece is delayed. By being supported by the supporting piece, the degree of deformation of the elastic piece due to the pressure of the toner becomes maximum in the central portion of the elastic piece. Therefore, the toner on both sides of the toner container moves to the central portion, but the moving directions of the toner from the left and right sides of the toner container to the central portion are different from each other, so that the movement action of the toner along the longitudinal direction of the elastic piece is suppressed. .

According to the second aspect of the invention, even if the elastic member receives the resistance of the toner and the supporting member is twisted to some extent,
By making the length of the support piece that supports the back side of the elastic piece on the rear side in the rotation direction longer at both ends and shorter toward the center,
The degree of deformation of the elastic piece due to the pressure of the toner becomes maximum in the central portion of the elastic piece. Therefore, the toner on both sides of the toner container moves to the central portion, but the moving directions of the toner from the left and right sides of the toner container to the central portion are different from each other, so that the movement action of the toner along the longitudinal direction of the elastic piece is suppressed. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. First, the toner supply paddle 1 is shown in FIG. In this toner supply paddle 1, two elastic pieces 3 formed of elastic thin pieces are provided on two opposite surfaces of a rod-shaped support member 2 having a quadrangular cross-sectional shape with a double-sided adhesive tape (not shown). It is formed by bonding. The support member 2 is made of synthetic resin, and has shaft portions 4 and 5 arranged on the same axis at both ends thereof and support pieces 6a and 6b for supporting the rear surface of the elastic piece 3 on the rear side in the rotation direction.
And are integrally formed.

Next, the developing device 7 is shown in FIG. In this developing device 7, a developing roller 10 and a supply roller 11 whose surface is made of a porous material such as sponge are rotatably provided in contact with each other in a toner container 9 containing a toner 8, and the developing roller 10 is also provided. A toner blade 12 that comes into contact with the toner container 10 is provided, and the shaft portions 4 and 5 (see FIGS. 1 and 2) of the toner supply paddle 1 described above are rotatably mounted on both side surfaces of the toner container 9, and one shaft portion 4 It is formed by fixedly fitting a gear (not shown) to the end of the. The gear fixed to the shaft portion 4 meshes with a final gear (not shown) of a drive mechanism including a motor.

In such a structure, when developing, as shown in FIG. 3, the developing roller 10 and the supply roller 1
1 and the toner supply paddle 1 are rotated counterclockwise.
In this case, the toner 8 in the toner container 9 is agitated by the elastic piece 3 of the toner supply paddle 1 and pressed against the surface of the porous material of the supply roller 11, and is charged by the friction between the supply roller 11 and the developing roller 10. Then, it is supplied to a photoconductor (not shown) through the developing roller 10.

The toner supply paddle 1 is rotated by applying a rotational force to the shaft portion 4 of the support member 2. However, since the toner pressure acts on the elastic piece 3 in the direction of arrow C shown in FIG. The shortage of the supporting member 2 made of synthetic resin is slightly twisted in the direction in which the rotational movement of the shaft portion 5 side is delayed relative to the shaft portion 4 side. However, since both sides of the elastic piece 3 are supported by the support pieces 6a and 6b, the central portion is deformed to the rearmost side in the rotation direction. This prevents the movement of the toner 8 from one side of the toner container 9 to the other side. That is, the toner container 9
The toner 8 on both sides of the
Since the moving directions D and E of the toner 8 from the left and right sides of the toner container 9 to the central portion are different from each other, the effect of canceling the action of moving the toner 8 from both sides of the toner container 9 to the central portion can be obtained. As a result, it is possible to suppress the movement of the toner 8 along the longitudinal direction of the elastic piece 3. Therefore, it is possible to reduce the difference in toner image density between the portions in the longitudinal direction of the photoconductor.

As described above, since the shaft portion 5 side of the elastic piece 3 delays the rotational movement with respect to the shaft portion 4 side, the support piece 6b for supporting the rear surface of the elastic piece 3 on the rear side in the rotation direction of the shaft portion 5 side. Is necessary. However, the support piece 6a that supports the rear surface of the elastic piece 3 on the rear side in the rotation direction on the side of the shaft portion 4 in the direction in which the rotational movement proceeds.
Is not always necessary and may be omitted. Further, the elastic member 3 supported by the supporting member 2 may be one, or may be fixed to each surface of the supporting member 2 as shown in FIG.

Next, the invention according to claim 2 will be described with reference to FIGS. 5 and 6. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted. The invention according to claim 2 is shown in FIG.
In place of the support pieces 6a and 6b in FIG. 2, a support wall 6c is formed integrally with the support member 2 so that the distance from the center of rotation of the support member 2 gradually decreases from both ends of the support member toward the central portion. The support wall 6c supports the rear surface of the elastic piece 3 on the rear side in the rotation direction.
Other structures are the same as those of the above embodiment.

In such a structure, the support member 2 is
When the elastic piece 3 is rotated in the direction shown in FIG.
Since it acts in the direction of arrow C shown in FIG. 3, the supporting member 2 made of synthetic resin, which lacks in rigidity, has a direction in which the rotational movement of the shaft portion 5 side is delayed more than the shaft portion 4 side to which the driving force is applied, as in the above embodiment. Can be twisted to some extent. However, since the support wall 6c that supports the elastic piece 3 has a shape in which the distance from the center of rotation of the support member 2 is long at both ends and becomes shorter toward the central portion, the central portion of the elastic piece 3 rotates most. Deforms to the rear side in the direction. This prevents the movement of the toner 8 from one side of the toner container 9 to the other side. That is, similar to the above-described embodiment, the toner 8 on both sides of the toner container 9 moves to the central portion, but since the moving directions D and E of the toner 8 from the left and right sides of the toner container 9 to the central portion are different from each other, It is possible to obtain the effect of canceling the effect of moving the toner 8 from both sides of the toner container 9 to the central portion. As a result, it is possible to suppress the movement of the toner 8 along the longitudinal direction of the elastic piece 3.

Also in the second aspect of the invention, the number of elastic pieces 3 supported by the support member 2 may be one, or may be fixed to each surface of the support member 2. However, in any case, the support wall 6c is provided on the support member 2 according to the number of the elastic pieces 3.

[0017]

According to the first aspect of the invention, at least the end of the supporting member for supporting the elastic piece for pressing the toner in the toner container in the direction not connected to the drive mechanism is rearward in the rotational direction of the elastic piece. By providing the support piece that supports the back surface on the side, even if the support member is twisted to some extent by the resistance of the toner that the elastic piece receives, the back surface on the rear side in the rotation direction at the end in the direction in which the rotational movement of the elastic piece is delayed is Since the support piece supports the elastic piece, the degree of deformation of the elastic piece due to the pressure of the toner can be maximized in the central portion of the elastic piece. Therefore, the toner on both sides of the toner container moves to the central portion. The range is less than half compared to the conventional case where the toner goes from one side to the other side of the toner container. Furthermore, since the moving directions of the toner from the left and right sides of the toner container to the central part are different from each other, the elastic piece It is possible to suppress the movement action of the toner in the longitudinal direction, which makes it possible to reduce the difference in toner image density on the photoreceptor.

According to the second aspect of the invention, the distance from the center of rotation of the supporting member to the supporting member for supporting the elastic piece for pressing the toner in the toner container goes from the both ends of the supporting member toward the central portion. By providing a supporting wall which is formed to have a gradually smaller size and supports the rear surface of the elastic piece on the rear side in the rotation direction, even if the supporting member is twisted to some extent by the resistance of the toner received by the elastic piece, Depending on the shape, the degree of deformation of the elastic piece due to the pressure of the toner can be maximized in the central portion of the elastic piece. Therefore, the toner on both sides of the toner container moves to the central portion, but the movement range is one part of the toner container. It is less than half compared to the conventional case of moving from one side to the other side, and since the moving direction of toner from the left and right sides of the toner container to the center part is different from each other, It is possible to suppress the movement action of the toner along, this makes it possible to reduce the difference in toner image density on the photoreceptor.

[Brief description of drawings]

FIG. 1 is a perspective view showing a toner supply paddle according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state when the toner supply paddle of FIG. 1 is rotated.

FIG. 3 is a vertical sectional side view of a developing device including the toner supply paddle of FIG.

FIG. 4 is a side view showing a modified example of the toner supply paddle.

FIG. 5 is a perspective view showing a toner supply paddle according to an embodiment of the invention as set forth in claim 2;

6 is a perspective view showing a state when the toner supply paddle of FIG. 5 is rotated.

FIG. 7 is a perspective view showing a conventional toner supply paddle.

FIG. 8 is a perspective view showing a state when the toner supply paddle of FIG. 7 is rotated.

[Explanation of symbols]

 2 Support Member 3 Elastic Pieces 6a, 6b Support Piece 6c Support Wall 8 Toner 9 Toner Container

Claims (2)

[Claims] 1. A rod-shaped support member made of synthetic resin, which is rotatably supported inside a toner container in which toner is accommodated and one end of which is connected to a drive mechanism including a motor, and a thin piece having elasticity. An elastic piece protruding in a direction orthogonal to the axial direction of the support member, and a support piece which is disposed at least at an end portion of the support member in a direction not connected to the drive mechanism and supports a rear surface of the elastic piece on the rear side in the rotation direction. And a toner supply paddle. 2. A rod-shaped support member made of synthetic resin, which is rotatably supported inside a toner container in which toner is accommodated and one end of which is connected to a drive mechanism including a motor, and a thin piece having elasticity. The elastic piece projecting in a direction orthogonal to the axial direction of the support member, and the distance from the center of rotation of the support member are defined such that the distance gradually decreases from both ends of the support member toward the central portion of the elastic piece. A toner supply paddle comprising a support wall that supports a rear surface on the rear side in the rotation direction.