JP2003307922A - Developing roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow air in the hole of an aluminum member to escape in the case where shafts are pressed into both ends of the aluminum member of a developing roller and the external circumferential surface of the aluminum member is coated in the subsequent process. <P>SOLUTION: A single-component developing device has: a developing roller 1 for forming a single-component toner layer on its surface and attaching toner to an image carrier on which an electrostatic latent image is formed by coming into contact with the image carrier, thereby rendering the electrostatic latent image visible; a toner supply roller being in contact with the developing roller 1 in order to supply toner; and a toner restricting member for restricting the toner on the developing roller 1, thereby forming a thin layer. In the developing roller 1 of the single-component developing device, the shafts 3 connected to a driving source are pressed into the hole 5 of the aluminum member 2 of the developing roller 1 from both of its ends and thus fixed in position. A groove 6 in the direction of thrust is formed in the internal face of the hole 5 of the aluminum member 2. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing roller used in an electrophotographic apparatus.

[0002]

2. Description of the Related Art In a one-component developing device, in order to prevent fog and ghost from occurring and maintain image quality, it is essential to charge the toner highly and uniformly. It is important to select the surface material of parts. On the other hand, due to environmental problems in recent years, prolonging the life of the device has become a major issue, but the toner regulating member on the surface of parts causes toner aggregation and sticking to the developing roller surface,
It is necessary to deal with the deterioration of the surface of the developing roller and the surface of the toner control member such as scratches, cracks, and peeling. Further, as a developing device, it is necessary to cope with contamination inside the image forming device due to toner leakage and scattering for long-term use, and in order to satisfy these requirements, high dimensional accuracy of parts is required. To be done.

FIGS. 3A and 3B show a developing roller 1 provided in a conventional developing device.
The shafts 3 are press-fitted and fixed to both ends of the aluminum member 2 having the reinforcing ribs 2a of the developing roller 1. A coating process is applied to the outer periphery of the aluminum member 2 in the next step, and a baking process is performed in the next step to form the coating film 4.

[0004]

However, such a conventional manufacturing method has the following problems. That is, since the shafts 3 are fixed to both ends of the aluminum member 2 by press fitting, air is sealed in the holes 5 of the aluminum member 2. In this state, the outer periphery of the aluminum member 2 is coated and a coating film 4 is applied by firing, so the air sealed in the holes 5 of the aluminum member 2 expands due to the heat during firing, and the air that has lost its place is press-fitted. Stick out the shaft 3. Further, although a drive source (not shown) is connected to the shaft 3, a high holding force is required for the aluminum member 2 and the shaft 3, and the press-fitting margin cannot be reduced. If the press-fitting margin is too large so that the shaft 3 does not project even if the air sealed by the heat of firing expands, the aluminum member 2 deforms in the outer peripheral direction and the axial position accuracy of both ends deteriorates.

Therefore, according to the present invention, when the shafts are fixed by press-fitting to both ends of the aluminum member of the developing roller and the outer periphery of the aluminum member is coated in the next step, air escape to the hole diameter of the aluminum member. It is an object of the present invention to provide a developing roller that can prevent the shaft from protruding due to heat during firing.

[0006]

In order to solve the above-mentioned problems, in the invention according to claim 1, a one-component toner layer is formed on the surface and brought into contact with an image carrier on which an electrostatic latent image is formed. A developing roller for adhering toner to visualize the electrostatic latent image,
In a hole of an aluminum member of the developing roller in a one-component developing device, which is arranged in contact with the developing roller and supplies a toner, and a toner regulating member that regulates the toner on the developing roller to form a thin layer. A developing roller, in which a shaft connected to a drive source is press-fitted from both ends to be fixed, the developing roller having a groove in the thrust direction on the inner surface of the hole of the aluminum member is the most main feature.

According to the second aspect of the invention, the main feature of the aluminum member of the developing roller according to the first aspect is that a groove is provided at a position corresponding to the reinforcing rib of the aluminum member.

According to the third aspect of the invention, in the aluminum member of the developing roller according to the first and second aspects, the main feature is that the relationship between the press fit margin and the groove depth is "press fit margin <groove depth". To do.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. An example of the developing roller 1 of the present invention according to claim 1 is shown in FIGS. Figure 1
In (a) and (b), the groove 6 extending in the thrust direction is provided on the inner surface of the hole 5 of the aluminum member 2 of the developing roller 1. The groove 6 may be provided in one place or a plurality of places.

According to the construction of the developing roller 1 shown in FIGS. 1 (a) and 1 (b), the air expanded by the heat during firing escapes from the groove 6 provided in the aluminum member 2, so that the shaft formed by the expanded air is discharged. The protrusion of 3 can be prevented. Further, since the aluminum member 2 is processed by extrusion molding, the shape of the groove 6 can be processed at the same time, the groove 6 can be provided at a plurality of places, and the cost can be the same as the current one. .

Another example of the developing roller 1 of the present invention according to claim 2 is shown in FIGS. 2 (a) and 2 (b). 2 (a), (b)
, The reinforcing ribs 2 of the aluminum member 2 of the developing roller 1
The groove 6 is provided at a position corresponding to a. If it is a portion corresponding to the reinforcing rib 2a of the aluminum member 2,
The number of the grooves 6 may be one or plural.

According to the structure of the developing roller 1 shown in FIGS. 2A and 2B, in addition to the function and effect of the developing roller 1 shown in FIGS. 1A and 1B, the reinforcing rib 2a of the aluminum member 2 is provided. Since the groove 6 is provided at the location corresponding to the portion, the depth of the groove 6 can be made deeper.

Further, FIGS. 1 (a), 1 (b) and 2
The grooves 6 formed in the holes 5 in the aluminum member 2 of the developing roller 1 shown in FIGS. 7A and 7B are formed so that the relationship between the press-fitting margin and the groove depth is "press-fitting margin <groove depth". . In this way, when the groove 6 is formed in the hole 5 in the aluminum member 2 of the developing roller 1 so that the groove depth is larger than the press-fitting margin, the groove 6 does not disappear even when the shaft 3 is press-fitted. Therefore, the air expanded during firing can be surely released.

[0014]

As described above, in the developing roller according to the first aspect of the invention, the air expanded by the heat during firing escapes from the groove provided in the aluminum member, so that the protruding of the shaft due to the expanded air is prevented. be able to. Further, since the aluminum member is processed by extrusion molding, the groove shape can be processed at the same time, so that the groove can be provided at a plurality of positions and the cost can be made equal to the current state.

According to the developing roller of the second aspect, in addition to the effect of the first aspect, since the groove is provided at the location corresponding to the aluminum member reinforcing rib portion, the groove depth can be made deeper.

According to the third aspect of the present invention, by setting the relationship between the press-fitting margin and the groove depth as "press-fitting margin <groove depth", the air expanded during firing can be surely released, so that the developing roller expands. It is possible to prevent the shaft from protruding due to air.

[Brief description of drawings]

1A is a cut front view showing an example of a developing roller of the present invention, and FIG. 1B is a cut side view thereof.

2A is a cut front view showing another example of the developing roller of the present invention, and FIG. 2B is a cut side view thereof.

3A is a cut front view showing an example of a conventional developing roller, and FIG. 3B is a cut side view thereof.

[Explanation of symbols]

1 developing roller 2 Aluminum member 2a Reinforcing rib 3 axes 5 holes 6 grooves

Claims (3)

[Claims] 1. A developing roller that forms a one-component toner layer on the surface and contacts an image bearing member on which an electrostatic latent image is formed to attach toner to visualize the electrostatic latent image; and a developing roller that contacts the developing roller. A drive source is connected to a hole of an aluminum member of the developing roller in a one-component developing device, which includes a toner supplying roller arranged to supply toner and a toner restricting member for restricting toner on the developing roller to form a thin layer A developing roller in which the shaft to be pressed is fixed from both ends,
A developing roller, wherein a groove in the thrust direction is provided on the inner surface of the hole of the aluminum member. 2. The developing roller according to claim 1, wherein a groove is provided at a position corresponding to the reinforcing rib of the aluminum member. 3. The developing roller aluminum member according to claim 1, wherein the relationship between the press-fitting margin and the groove depth is “press-fitting margin <groove depth”.