JP2569299Y2 - Photoreceptor drum mounting mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

[Field of application of the invention] This invention is based on the fact that a flange is provided at both ends of a photosensitive drum of an electrophotographic printer or a copying machine.
For fitting the relates to a photosensitive drum mounting mechanism.

[0002]

2. Description of the Related Art In general, a photosensitive drum is provided with flanges at both ends so that a shaft such as a rotating shaft or a fixed shaft is connected to the photosensitive drum. The flange of the photosensitive drum
(1) It has a role of grounding the inner surface of the base or the like around a shaft, and requires some conductivity. When using a non-conductive material such as plastic for the flange, provide a conductive member on the flange,
It has been proposed to electrically connect the inner surface of the photosensitive drum and the shaft (for example, see JP-A-2-83572, JP-A-2-254484).

FIG. 4 shows a flange disclosed in JP-A-2-83572. In the figure, 01 is a shaft, 02 is a plastic flange, and 03 is a spring coil. However, if the photosensitive drum and the shaft 01 are to be securely connected by the flange of FIG. 4, the spring coil 03 must be hard. Such a spring coil 03
Is inserted from the end surface of the photosensitive drum, the contact portion between the spring coil 03 and the photosensitive drum is damaged, and the inner peripheral surface of the photosensitive drum is damaged. Such scratches cause the photosensitive drum to be eccentric with respect to the axis 01,
Decrease image accuracy. Harder spring coil 0
It is difficult to set the photoconductor drum 3 on the photosensitive drum while pushing it into the hole of the flange 02.

The flange disclosed in Japanese Patent Application Laid-Open No. 2-254484 is provided with an Al ring on the outer periphery of the flange along the contact surface with the photosensitive drum. Although such a flange can surely have conductivity, the use of a non-metal flange having a complicated shape is lost. That is, the nonmetallic flange is used to reduce the cost of the flange. Here, if an Al ring having a complicated shape is provided on the flange, the overall cost is not much different from the case of using a metal flange from the beginning.

[0005]

SUMMARY OF THE INVENTION Problems to be solved by the present invention are as follows: (1) to obtain conductivity between the photosensitive drum and the shaft; (2) to damage the inner peripheral surface of the photosensitive drum. (3) To provide a photosensitive drum mounting mechanism that can easily and easily fit a flange and improve rotational accuracy, and (3) maintain a correct positional relationship between a photosensitive drum and a flange.
It is in.

[0006]

[Configuration of invention] This invention is hula across the photosensitive drum
A photosensitive drum supporting the photosensitive drum
Mechanism with a shaft or bearing located at the center
A conductive flange body, a through hole communicating with the shaft side,
An insertion hole having a through hole communicating with the photosensitive drum side is provided.
Then, a conductive elastic member is inserted into the insertion hole in a direction parallel to the axis.
Insert and store, insert both ends through both through holes,
Abut against the inner peripheral surface of the body drum and each of the shaft or bearing
It is characterized by having.

[0007]

[Function of the Invention] In the photosensitive drum mounting mechanism of the invention,
Conductive elasticity when assembling flange to photoconductor drum
The flange is fitted to the inner periphery of the photosensitive drum without any member.
Next, a conductive elastic member is inserted into the insertion hole of the flange,
From the near side of the ram, insert it parallel to the shaft or bearing. Soshi
And a first through hole and a second through hole at both ends of the conductive elastic member.
When set to, the conductive member expands with elasticity, and both ends are automatically
Contact the inner peripheral surface of the photosensitive drum and the shaft or bearing
You. As a result, it is easy to attach the flange to the photosensitive drum.
And damage the inner surface of the photoreceptor drum during installation
There is no. As a result, the rotational accuracy of the photosensitive drum
There is no decrease in the degree, and the image accuracy can be kept high.
In addition, the conductive elastic member ensures that the photosensitive drum is elastic.
Ground the inner surface of the shaft to a shaft or rail. Further conductive elastic members
Can be used because it is easy to assemble.
Combines photoreceptor drum and flange with elasticity to position
Can be used.

[0008]

FIG. 1 shows a photosensitive drum mounting mechanism according to an embodiment. In the figure, reference numeral 2 denotes a metal fixed shaft of an electrophotographic application device such as a printer, and 4 denotes a flange body made of a non-conductive material such as plastic such as ABS resin. 6 is a bearing using a ball bearing, and 8 is the ball.
Reference numeral 10 denotes an insertion hole for the conductive elastic member, which may be a through hole or a bottomed hole . In the case of a bottomed hole , a bottom is provided on the right side of the drawing (the back side of the photosensitive drum). Reference numeral 12 denotes a shaft-side through hole (first through hole) communicating with the insertion hole 10, and penetrates to the bearing 6. Reference numeral 14 denotes a through hole (second through hole) on the photosensitive drum side communicating with the insertion hole 10 and penetrates to the inner peripheral surface of the photosensitive drum. Reference numeral 16 denotes a conductive elastic member made of a spring or the like obtained by bending a wire such as SWAP steel into a V-shape. The conductive elastic member 16 may be a torsion coil spring, a compression coil spring, a leaf spring, a conductive rubber, or the like. A spring that can hold the inner peripheral surface of the photosensitive drum and the flange body 4 integrally by spring pressure. What is necessary is just to have sufficient conductivity and sufficient conductivity to the ground.

It is preferable that a plurality of insertion holes 10 are provided symmetrically with respect to the shaft 2 in the flange body 4, for example, two, three, four, six, eight, and the like. At this time, it is preferable to use a plurality of elastic members 16, for example, two, three, or four, and to arrange them symmetrically with respect to the axis 2. Reference numeral 18 denotes a fitting surface between the inner peripheral surface of the photosensitive drum and the flange body 4.

[0010] Instead of the fixed shaft 2, a flange may be attached to a rotating shaft for rotating the photosensitive drum. In this case, the bearing 6 is unnecessary. The bearing 6 may be a roller bearing or the like, and the flange body 4 may be slid directly on the fixed shaft 2 without using the bearing 6. in this case,
The through hole 12 on the shaft side is extended to the fixed shaft 2, and the end of the conductive elastic member 16 on the shaft side is slid on the fixed shaft 2.

The flange body 4 is manufactured by injection molding a hard resin such as an ABS resin, and an insertion hole 10 is formed at the time of molding. After molding, the through holes 12, 1 are formed by, for example, machining.
4 is provided.

The operation of the flange will be described with reference to FIGS. In FIG. 2, reference numeral 20 denotes a photosensitive drum, which is provided with a photosensitive layer such as amorphous silicon on the surface of an Al pipe. The flange main body 4 is fitted to the inner peripheral surfaces at both ends of the photosensitive drum 20 at the fitting surface 18. At this time, the conductive elastic member 16 is not removed from the flange body 4.
Next, the conductive elastic member 16 is inserted through the insertion hole 10, and the axial end of the conductive elastic member 16 is aligned with the through hole 12, and the photosensitive drum side end is aligned with the through hole 14. Then, due to the spring pressure of the conductive elastic member 16, each end comes into contact with the bearing 6 and the inner peripheral surface of the photosensitive drum 20, and both are integrally held. Since both ends of the conductive elastic member 16 contact the inner peripheral surface of the photosensitive drum 20 and the bearing 6, the photosensitive drum 20 is grounded to the shaft 2 via the conductive elastic member 16 and the bearing 6. It is preferable that the inner diameters of the through holes 12 and 14 and the diameter of the end of the conductive elastic member 16 be substantially equal to each other so that play in the through holes 12 and 14 does not occur.

Since the conductive elastic member 16 is inserted after the flange main body 4 is fitted to the photosensitive drum 20 in this manner, the inner peripheral surface of the photosensitive drum 20 can be easily mounted without damaging it. The photosensitive drum 20 and the fixed shaft 2 can be electrically connected. Further, since the attachment is easy, the elasticity of the conductive elastic member 16 can be increased, and the flange main body 4 and the photosensitive drum 20 can be securely connected.

As shown in FIG. 3, the insertion hole 10 is
Are symmetrically arranged, for example, two, three, four, eight, etc. The conductive elastic member 16 may be, for example, 2
A plurality of such as three, four, etc. are inserted. In the drawing, four conductive elastic members 16 are arranged axially symmetrically with respect to eight insertion holes 10. If a plurality of insertion holes 10 are provided axially symmetrically in this way, the conductivity will be more reliable and the rotation accuracy will be higher.

[0015]

[Effects of the Invention] The present invention has the following effects. (1) Reliable conductivity is obtained between the photosensitive drum and the shaft. (2) An inexpensive flange such as a resin molded product can be used, and the cost of the flange is reduced. (3) The flange can be easily fitted without damaging the inner peripheral surface of the photoconductor drum, and the positional relationship between the flange and the photoconductor drum can be maintained correctly, so that the rotation accuracy is improved. As a result, a high quality image can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment.

FIG. 2 is a cross-sectional view illustrating a mounted state of a photosensitive drum in the embodiment.

FIG. 3 is a side view of the embodiment.

FIG. 4 is a sectional view of a conventional example.

Claims (1)

(57) [Scope of request for utility model registration] A flange is fitted to both ends of a photosensitive drum.
A photosensitive drum mounting mechanism for supporting the photosensitive drum.
There are, non-conductive flange body disposed shaft or bearing to the center
And a through hole communicating with the shaft side and a photosensitive drum side.
And an insertion hole having a through hole formed therein, and the insertion hole is electrically conductive.
Insert and store the elastic member in the direction parallel to the axis,
Through both through holes, and the inner circumferential surface of the photosensitive drum and
Characterized by being brought into contact with each of the shaft or the bearing,
Photoconductor drum mounting mechanism.