JP3885451B2 - Electrophotographic photoreceptor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photoreceptor. More specifically, the present invention relates to a mechanical structure of an electrophotographic photosensitive member using a specially shaped ground plate and a central axis.
[0002]
[Prior art]
An electrophotographic photosensitive member is used in electrophotographic apparatuses such as copying machines, printers, and facsimiles. As this electrophotographic photosensitive member, a drum type electrophotographic photosensitive member in which flanges are attached to both ends of a cylindrical drum having a photosensitive coating film formed on the outer peripheral surface is generally known.
[0003]
It is known that an electrophotographic photosensitive member is provided with a ground plate for electrical connection with the photosensitive member. For example, in Japanese Patent Application Laid-Open No. 11-258951, a contact point is provided by providing a groove at a contact point between a ground plate and a central axis. A technique for increasing the area is disclosed.
[0004]
[Problems to be solved by the invention]
However, since the strength of the ground plate is not sufficient, when the central shaft is taken in and out of the electrophotographic photosensitive member, the ground plate (6 in FIG. 3) remains in the center shaft groove (FIG. 5) and the central shaft is In some cases, the ground plate is deformed due to excessive force applied to the ground plate.
[0005]
[Means for Solving the Problems]
The present invention was made as a result of intensive studies to solve the above-described problems, and according to an electrophotographic photoreceptor using a flange for an electrophotographic photoreceptor using a special-shaped ground plate and a central shaft having a special shape. It has been found that the above problems can be solved.
Ie, Abstract of the present invention is provided at an end of the cylindrical drum, and an electrophotographic photoreceptor flange which is supported via a central shaft passing through the cylindrical drum, said flange groove And an angle formed by a side surface of the groove portion connecting the bottom portion of the groove and the surface of the central shaft and the bottom portion of the groove is 95 degrees or more and 160 degrees or less, The plate has a bent portion at a contact portion with the central axis, the bent portion is R 0.2 mm or more, and a bent angle of the bent portion is an angle of 90 degrees to 150 degrees. The electrophotographic photosensitive member is characterized in that a flange for an electrophotographic photosensitive member is used at least at one end of a cylindrical drum . If the ground plate has such a shape, sufficient strength and elasticity can be obtained. In addition, an electrophotographic photosensitive member having a groove on the central axis is particularly preferable because the ground plate can be effectively prevented from being caught in the groove when the central axis is inserted and removed.
[0006]
Upper Symbol flange, it is possible to effectively use the electrophotographic photosensitive member. The present invention is particularly preferably used in the case of an electrophotographic photoreceptor in which the groove of the central axis has a groove width of 1 mm or more and 3 mm or less and a groove depth of 0.5 mm or more and 1.5 mm or less. If the groove of the central shaft has such a shape, it is possible to secure a contact point between the ground plate and the central shaft, and it is possible to suitably ground. In addition, the present invention is suitably used for an electrophotographic photosensitive member in which an angle formed by a side surface of a groove portion connecting the bottom portion of the central axis and the surface of the central shaft and a bottom portion of the groove is 95 degrees or more and 160 degrees or less. Thus, if the angle formed by the side surface of the groove and the bottom of the groove is an obtuse angle, the earth plate passes through the groove relatively smoothly even when the central axis is taken in and out of the electrophotographic photosensitive member. The present invention is preferably used for an electrophotographic photosensitive member in which the vicinity of the central axis surface of the central axis and the side surface of the groove intersects with a C surface or an R. By performing such processing on the central axis, the earth plate smoothly passes through the groove when the central axis is taken in and out of the electrophotographic photosensitive member.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the electrophotographic photosensitive member according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the overall structure of the first embodiment, FIG. 2 is a view showing a front end portion of a ground plate, which is a main part of the first embodiment, and FIG. 3 is a view showing a front end portion of a conventional ground plate. FIG. 5 is a diagram showing an embodiment of the groove portion of the central shaft that is the main part of the embodiment of the present invention, FIG. 5 is a diagram showing an embodiment of the groove portion of the central shaft that is the main portion of another embodiment of the present invention, These are figures showing the groove part of the central axis in a prior art example.
[0008]
In the electrophotographic photosensitive member of the present invention, as shown in FIG. 1, synthetic resin flanges 2 and 3 attached to both ends of a cylindrical drum 1 are supported via a central shaft 4. A metal e-ring is press-fitted into the groove portion of the central shaft. Both flanges 2 and 3 are fixed by an e-ring 5 press-fitted into the groove portion of the central shaft. The ground plate 6 is grounded by contacting the central shaft 4.
[0009]
The cylindrical drum 1 is formed by forming a photosensitive coating on the surface of a cylindrical substrate finished with high precision roundness and cylindricity, and has an outer diameter of 15 to depending on the electrophotographic OA equipment used. The length is set to about 200 to 1100 mm to about 130 mm. In the present embodiment, the outer diameter of the drum 1 is set to about 20 mm to about 100 mm depending on the application.
[0010]
Examples of the material of the cylindrical drum include metal materials such as aluminum, brass, and stainless steel, or polymer materials such as polyethylene terephthalate, polybutylene terephthalate, polypropylene, nylon, polystyrene, and phenol resin. The photosensitive coating film is formed, for example, by immersing a cylindrical substrate in a known coating solution prepared by mixing a charge generating substance, a charge transporting substance, a binder resin and a solvent.
[0011]
Examples of the charge generation material include azo pigments and disazo pigments, and examples of the charge transport material include polyaromatic compounds such as anthracene or hydrazone compounds. In addition, examples of the binder resin include polymethacrylic acid esters and cellulose esters, and examples of the solvent include n-butylamine, diethylamine, and methyl cellosolve acetate.
[0012]
In the flanges 2 and 3, the thickness of each part is substantially uniform, and the large diameter cylindrical parts 2b and 3b and the small diameter cylindrical parts 2a and 3a are injection-molded with high concentricity. In such flanges 2 and 3, the outer periphery of the large diameter cylindrical portion is fitted to the inner periphery of the cylindrical drum 1, and the central shaft 4 is fitted to the inner periphery of the small diameter cylindrical portions 2 a and 3 a.
[0013]
As the molding resin for the flanges 2 and 3, a general-purpose engineering resin that is easily available and inexpensive can be used. In this case, it is preferable that the resin used has conductivity. Further, the linear expansion coefficient of the resin used is close to the linear expansion coefficient of the cylindrical base body of the drum 1, that is, when the cylindrical base body is made of aluminum, the linear expansion coefficient is close to the linear expansion coefficient of aluminum. It is preferable to use a resin.
[0014]
The central axis 4 is made of, for example, stainless steel that has a diameter of about 5 to 20 mm and is ground, and may be a single axis that penetrates the electrophotographic photosensitive member as shown in the drawing. A pair of right and left may be arranged on the same axis fixed on the photographic OA device side. When the central shaft 4 is closely fitted to the inner periphery of the small diameter cylindrical portion 5B, the drum 1 is rotatably supported by the electrophotographic OA device via the base member 5. Groove of the central axis, to ensure the contact between the grounding plate and the central axis, depending on the size of the grounding plate and the electrophotographic photosensitive member, in general, the groove width is 1mm 3mm or more or less Is more preferable, and more preferably 1 to 2 mm. Moreover, as a depth of a groove | channel, 0.5 mm or more and 1.5 mm or less are preferable, and 0.5 mm or more and 1 mm or less are more preferable. If the grooves of the central axis is in such a shape, it is possible to take a suitably ground becomes possible above. As shown in FIG. 4, when the angle formed by the side surface 7a of the groove portion connecting the bottom portion of the central axis and the surface of the central shaft and the bottom portion 7b of the groove is an obtuse angle, the central shaft is taken in and out of the electrophotographic photosensitive member. However, it is preferable because the ground plate passes through the groove relatively smoothly. The angle formed by the side surface of the groove and the bottom of the groove is preferably 95 degrees or more and 160 degrees or less, and more preferably 100 degrees or more and 145 degrees or less. As shown in FIG. 5, when the central axis surface of the central axis and the side surface of the groove intersect each other, the ground plate is more smoothly rounded when the central axis is taken in and out of the electrophotographic photosensitive member if it is somewhat rounded. Therefore, it is desirable that the vicinity of the center axis surface of the center axis and the side surface of the groove be C-plane processed or R-processed. Here, the C-plane process means a process of cutting off an arbitrary corner part obliquely and providing a taper, and the R process means a process of processing an arbitrary corner part into an arc shape.
[0015]
In the present invention, at least one of the flanges at both ends of the drum has a ground plate in contact with the central axis. The ground plate is used to ground the drum.
The material of the ground plate is not particularly limited as long as it has a certain degree of conductivity, and examples thereof include iron, aluminum, and copper. Among these, iron is preferable from the viewpoints of flexibility and rigidity.
The ground plate is bent at the contact portion with the central axis. The tip shape of the contact point with the center axis of the ground plate is stronger and more elastic when rounded to some extent as shown in Fig. 2, and it is also compared when the center axis is taken in and out of the electrophotographic photosensitive member. It is desirable for the ground plate to pass through the groove smoothly and smoothly, preferably R0.2 mm or more, and more preferably R0.3 mm or more. On the other hand, the preferred roundness of the contact portion with the center axis of the ground plate varies depending on the depth of the groove of the center shaft and the shape of the ground plate, but is preferably R5 or less.
In addition, as shown in FIG. 2, it is preferable that the contact portion with the central axis of the ground plate has a certain angle because the strength of the ground plate can be secured and the groove can be smoothly passed. The contact portion with the central axis of the ground plate preferably has an angle of 90 to 150 degrees, more preferably 130 to 150 degrees.
[0016]
Next, a usage example of the electrophotographic photosensitive member of the embodiment configured as described above will be described. In this electrophotographic photosensitive member, as shown in FIG. 1, flanges 2 and 3 are rotatably supported by a central shaft 4, and external teeth (not shown) of gear members fitted to the flange are electrophotographic OA. By being engaged with the drive gear on the device side, it is rotationally driven at a predetermined rotational speed.
[0017]
【The invention's effect】
According to the present invention, there is an effect that the central axis can be taken in and out of the electrophotographic photosensitive member without deforming the ground plate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall structure of a first embodiment.
FIG. 2 is an enlarged view of a front end portion of a ground plate, which is a main part of the first embodiment.
FIG. 3 shows a conventional earth plate tip.
FIG. 4 is a view showing one form of a groove portion of a central shaft, which is a main part of the embodiment of the present invention.
FIG. 5 is a diagram showing an embodiment of a groove portion of a central shaft that is a main part of another embodiment of the present invention.
FIG. 6 is a view showing a groove portion of a central axis in a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical drum 2 Flange 2a Small-diameter cylinder part 2b Large-diameter cylinder part 3 Flange 3a Small-diameter cylinder part 3b Large-diameter cylinder part 4 Center shaft 5 E-ring 6 Ground plate 7 Center-axis groove part 7a Groove side surface 7b Groove part bottom face

Claims (3)

A flange for an electrophotographic photosensitive member provided at an end of a cylindrical drum and supported via a central axis that penetrates the cylindrical drum,
The flange has a ground plate in contact with the central axis having a groove, and an angle formed by a side surface of the groove portion connecting the bottom portion of the groove and the surface of the central shaft and the bottom portion of the groove is not less than 95 degrees and not more than 160 degrees. The ground plate has a bent portion at the contact portion with the central axis, the bent portion is R 0.2 mm or more, and the bent angle of the bent portion is an angle of 90 to 150 degrees. An electrophotographic photosensitive member characterized by using a flange for an electrophotographic photosensitive member at least at one end of a cylindrical drum. 2. The electrophotographic photosensitive member according to claim 1 , wherein the groove width of the central axis groove is 1 mm or more and 3 mm or less, and the groove depth is 0.5 mm or more and 1.5 mm or less. Nearby intersection of the side surface of the central shaft surface and the groove of the central axis, C face treatment or electrophotographic photosensitive member according to claim 1 or 2, characterized in that it is R processed.

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