JP2643824B2 - Electrode connection method for photoreceptor drum and connection device used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a facsimile or a copying machine using an electrophotographic process, and more particularly to a method for connecting electrodes of a photosensitive drum used in an electrophotographic process and the connection thereof. To a device that

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic process, a photosensitive drum having a photosensitive layer applied outside is used. This photoreceptor drum uses a base made of a tube made of conductive aluminum or an alloy thereof, forms an insulating alumite layer on its surface by performing alumite treatment for preventing charge injection, and forms an outer layer portion on the outer layer. For example, it is manufactured by applying a photosensitive layer in which a charge generation layer and a charge transport layer are laminated. Such a photoreceptor drum uses an alumite layer to prevent charge injection.
For example, the thermal characteristics and the withstand voltage characteristics of the photosensitive drum are more stable than those using an insulating resin or the like.

When the photosensitive drum is actually used by being incorporated in an image forming apparatus, it is necessary to apply a charge or to apply an electric field in a charging step, a developing step, and a transferring step. Since the substrate needs to be electrically connected to an electrode member that is electrically connected to an external charging unit or developing unit, a conductive process is performed between the electrode member and the drum substrate.

Normally, the conducting process of the photosensitive drum is performed by inserting a sharp electrode member into the photosensitive drum under pressure and cutting off the alumite layer covering the base of the drum. The electrode member is in a conductive state. The photoconductor drum is rotatably supported when mounted on an electrophotographic apparatus, and is driven to rotate. Therefore, a flange having a gear or the like is mounted on one end of the photoconductor drum. Further, generally, when a flange is mounted on the photosensitive drum, an electrode member is attached to the flange to electrically connect the electrode member to a base of the photosensitive drum.

By mounting the flange to which the electrode member is attached to the end of the photoreceptor, the electrode member attached to the flange damages the alumite layer on the inner surface of the substrate and peels off the alumite layer. Is electrically connected to the base. At this time, the conduction process of the photosensitive drum is completed by connecting the electrode member to the ground electrode or other electrode side of the charging unit or the developing unit.

In the above conduction process, the connection between the electrode member and the substrate is very important for forming an image. If the connection is incomplete, the photosensitive drum does not function and an image cannot be obtained. There are cases. Further, since the hardness of the alumite layer is high, it is necessary to press the electrode member into the inside of the photoreceptor drum with a strong force so that the alumite layer is shaved with a strong force and securely connected to the base. In addition, a continuity test was required to confirm that the electrode member and the substrate of the photoreceptor were electrically connected securely.

[0007]

When the electrode member is pressed into the end portion of the photoreceptor with a strong force to cut the alumite layer and conduct the conduction process, it is necessary to increase the force to obtain a reliable connection. , 0.5-1 mm, the aluminum base of the photosensitive drum may be deformed. In addition, there is a high possibility that a connection is not generated due to a variation in force, and the connection must be checked by a continuity test.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. It is an object of the present invention to ensure that conduction between an alumite-treated photosensitive member substrate and an electrode member does not cause deformation of an aluminum substrate. The operation of scraping the alumite layer with the electrode member is not performed, and a constant conduction state can be maintained at all times. To provide an apparatus for the same.

[0009]

According to the present invention, there is provided a drum substrate of a photosensitive drum having a photosensitive layer for forming a charge latent image by light on an outer peripheral surface of a drum substrate made of a metal having an insulating film on the surface. In a method for connecting an electrode member to a photoconductor drum for connecting an electrode member for connection to an external circuit, a step of incorporating the electrode member into a contact state inside the photoconductor drum, and an area of contact with an inner surface of the photoconductor drum include: A step of contacting an external electrode which is several times or more the contact area between the inner surface of the drum and the electrode member, and a step of applying a pulse voltage between the member and the external electrode to cause dielectric breakdown of the insulating film contacting the electrode member And a step of removing the external electrodes, thereby obtaining an electrode connection method for the photosensitive drum.

According to the present invention, an external circuit and a photoconductor drum having a photoconductor layer for forming a charge latent image by light on the outer peripheral surface of the metal drum substrate having an insulating film on the surface are provided. The device used in the step of connecting the electrode members for connection is obtained.

The apparatus includes a flange which is inserted from one end of the photosensitive drum while holding the electrode member, and a flange which makes the electrode member contact the inner surface of the photosensitive drum, and a flange which is inserted from the other end of the photosensitive drum. And an external electrode whose contact area with the inner surface of the photosensitive drum is several times or more the contact area between the inner surface of the photosensitive drum and the electrode member. And a pulse voltage generating source for applying a pulse voltage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments with reference to the drawings.

The method for connecting the electrodes of the photosensitive drum according to the present invention is carried out using the electrodes shown in FIGS.

In FIG. 2, a photoreceptor drum 1 is formed by forming a photoreceptor layer on the outer peripheral surface of a 0.5 to 1 mm thick tube made of aluminum or an aluminum alloy, the entire surface of which is anodized. The electrode 5 shown in FIG. 1 is inserted into one end, and the electrode member 2 and the flange 3 shown in FIG. 3 for grounding to the outside are inserted into the other end. Here, the electrode member 2 is an electrode for connecting to the aluminum tube of the photoconductor drum 1, and is fixed on the central axis of the flange 3 of the insulator and is connected with the flange 3 even after the connection with the flange 3.
It will not be removed from. However, the electrode 5 is removed after the connection of the electrode member 2 is completed.

In FIG. 1, the electrode 5 has a base 9 made of a conductor such as metal and the outer periphery of a small-diameter portion of a column is covered with a cylindrical elastic conductive member 7 made of conductive rubber.
The outer diameter of the cylindrical elastic conductive member 7 is adjusted to the inner diameter of the photosensitive drum 1 as shown in FIG. Therefore, the cylindrical elastic conductive member 7 elastically adheres to the alumite film on the inner surface of the photosensitive drum 1.

As shown in FIG. 3, the electrode member 2 has a pair of terminals 8 each having a sharp end, and is inserted into the projection 30 of the flange 3 through a pair of holes 80 and held on the central axis of the flange. You. The central axis of the flange 3 is hollow,
An external electrode is inserted from one end of the flange 3 into the electrode member 2 so as to be in contact therewith. The radius of the smallest circle connecting the tips of the terminals 8 of the electrode member 2 is made larger than the inner diameter of the photosensitive drum 1. The electrode member 2 is made of metal, for example,
It is made of a metal such as phosphor bronze, copper, iron, stainless steel or the like, and its thickness is such that when the electrode member 2 is attached to the photosensitive drum together with the flange 3 and the terminal portion is bent, it contacts the inner surface of the photosensitive drum 1. At this time, the photosensitive drum is selected so that the raw tube of the photosensitive drum does not deform. At this time, it is not necessary that the terminal 8 and the aluminum tube of the photosensitive drum 1 are electrically connected by peeling the alumite film.

The flange 3 has a gear portion 31 formed on the outer peripheral surface thereof, so that a torque can be transmitted to the photosensitive drum 1 via a gear of a driving means during electrophotographic recording.

As described above, the electrodes 5 and the flanges 3 having the electrode members 2 are provided from both ends of the photosensitive drum 1 respectively.
Is inserted, as shown in FIG. 2, the electrode 4 connected to one electrode of the pulse electrode (hereinafter, referred to as a power supply) 6 is
It is inserted into the hole of the central axis of the flange 3 and comes into contact with the electrode member 2. The other electrode of the power supply 6 is connected to the base 9 of the electrode 5.

After the contact, the power supply 6 applies a voltage equal to or higher than the dielectric breakdown voltage of the alumite film to the alumite film normally used for a photoreceptor.
1 kv or more, preferably 1.5 k
A pulse voltage of about v or more is applied. At this time, since the terminal 8 and the electrode 5 of the electrode member 2 are in contact with the alumite film on the inner surface of the photosensitive drum 1, most of the applied voltage is distributed to the alumite film which is the insulating portion.

At this time, since the contact of the terminal 8 of the electrode member 2 is almost a point contact as compared with the electrode 5 which is in contact with a wide surface,
Most of the applied voltage concentrates on the contact portion between the terminal 8 and the alumite film. Therefore, when a high voltage pulse equal to or greater than the dielectric breakdown of the alumite film is applied, the alumite film is broken down at the terminal contact portion, and the tip of the terminal 8 is electrically connected to the aluminum tube by heat or the like due to spark. Thereafter, the electrodes 4 and 5 are extracted. As described above, reliable conduction between the alumite-treated aluminum tube and the electrode member 2 can be obtained.

In this embodiment, since the voltage distributed to the terminal 8 and the electrode 5 of the electrode member 2 is inversely proportional to the contact area, the contact area of the electrode 5 with respect to the photosensitive drum 1 is smaller than that of the terminal 8. There is no practical problem if it is at least twice, preferably at least ten times.

The pulse power supply used in this embodiment is processed by a commonly known method such as a current limiting circuit when an insulating film is destroyed and a spark is generated so that an excessive current does not damage the electrode tip or the aluminum tube. Is done.

In the above embodiment, the cylindrical elastic conductor is used for the portion of the electrode that comes into contact with the aluminum tube. However, the present invention is not limited to this. The effect of the present invention can be obtained by making the inner tube substantially uniformly and uniformly contact with the inner diameter of the base tube and increasing the contact area. Further, the base tube of the photosensitive drum 1 may be made of a metal other than aluminum, and the alumite film may be replaced with another insulating film.

In the present invention, by monitoring the current when a pulse voltage is applied, it is possible to simultaneously confirm whether or not dielectric breakdown has occurred. When the dielectric breakdown is not obtained, the voltage may be applied again, or the pulse voltage may be increased and the voltage may be applied again until the dielectric breakdown is obtained.

The electrode member 2 is connected to an electrode which is connected to a charging section and a developing section of the electrophotographic apparatus. Fig. 2
Is inserted from the hollow portion of the flange 3 in the same manner as the electrode 4 of FIG.

[0026]

As described above, according to the present invention,
In the connection between the photoconductor drum and the electrode member, the insulating film such as the alumite film of the metal tube of the photoconductor drum is broken by application of a pulse voltage that causes dielectric breakdown, and is electrically connected. The electrode can be easily connected by pressing the electrode against the aluminum tube from the inside.
As a result, it is possible to prevent the photosensitive drum from being deformed and the conduction state from becoming uneven. Therefore, there is no need to perform a continuity test or the like. In addition, by employing an electrode structure in which the electrode member to be connected and the electrode facing the electrode are in wide contact with the alumite film, the applied voltage can be effectively concentrated on the electrode member, and dielectric breakdown failure and the like can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one of electrodes of a connection device used in a method for connecting electrodes of a photosensitive drum according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an electrode connection method according to an embodiment of the present invention.

FIG. 3 is a perspective view showing a flange and an electrode member of a connection device used in the electrode connection method according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Electrode member 3 Flange 5 Electrode

Claims (7)

(57) [Claims] An external circuit is connected to the drum substrate of a photosensitive drum having a photosensitive layer on which a charge latent image is formed by light on the outer peripheral surface of a drum substrate made of metal whose surface is covered with an insulating film. A method of connecting the electrode member to the inside of the photoconductor drum in a contact state, and an area of contacting an inner surface of the photoconductor drum with the inner surface of the photoconductor drum. Contacting an external electrode that is several times or more the contact area with the electrode member, and applying a pulse voltage between the electrode member and the external electrode to cause dielectric breakdown of the insulating film that contacts the electrode member. The process of
Removing the external electrode from the photoconductor drum. 2. The electrode member is fixed on a central axis of a flange, and as the flange is inserted from one end of the photosensitive drum, the electrode member contacts an inner surface of the photosensitive drum. The method for connecting electrodes of a photosensitive drum according to claim 1. 3. The flange has a hollow hole in a central axis,
The method according to claim 2, wherein the pulse voltage to the electrode member is applied through an electrode that contacts the electrode member through the hollow hole. 4. An external circuit is connected to the drum substrate of the photoconductor drum having a photoconductor layer for forming a charge latent image by light on an outer peripheral surface of the drum substrate made of metal whose surface is covered with an insulating film. A device used in the step of connecting the electrode member, wherein the flange is inserted from one end of the photosensitive drum while holding the electrode member, and the charge member contacts the inner surface of the photosensitive drum; An external electrode that is inserted from the other end of the drum, contacts the inner surface of the photoconductor drum, and has a contact area that is several times or more the contact area between the inner surface of the photoconductor drum and the electrode member; And a pulse voltage source for applying a pulse voltage equal to or higher than the dielectric breakdown voltage of the insulating film between the external electrodes. 5. The flange has a hollow hole in a central axis,
5. The apparatus according to claim 4, wherein the electrode member is held on the central axis. 6. The apparatus according to claim 5, wherein the pulse voltage generation source has an electrode inserted into a hollow hole of the flange and coming into contact with the electrode member. 7. The electrode connection for a photosensitive drum according to claim 4, wherein the external electrode includes an elastic conductive member that is in close contact with the inner surface of the photosensitive drum and a base that supports the elastic conductive member. apparatus.