JP2007285965A - Method and device for continuity inspection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for continuity inspection capable of simply and accurately inspecting the continuity between an electrophotographic photoreceptor and a grounding plate. <P>SOLUTION: The method and device for continuity inspection is to inspect continuity between electrophotographic photoreceptor having a photosensitive layer on the surface of a drum element pipe and the grounding plate attached to the end of the drum element pipe. The device comprises a long-shaped serrated electrode arranged so as to oppose to the photosensitive layer, a voltage applying means for applying voltage to the serrated electrode, and a rotation means for rotating/driving the electrophotographic photoreceptor around a cylindrical axis. The method includes a step of applying voltage to the serrated electrode by the voltage applying means while rotating the electrophotographic photoreceptor by the rotation means, and a step of determining continuity based on the current density of a discharge current flowing from the serrated electrode toward the surface of the electrophotographic photoreceptor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a continuity test method and a continuity test apparatus used therefor. In particular, the present invention relates to a continuity inspection method and a continuity inspection apparatus capable of simply and accurately inspecting continuity between an electrophotographic photosensitive member and a ground plate attached to a flange.

In general, an electrophotographic photosensitive member used for an electrophotographic machine such as a copying machine or a laser printer has an inorganic photosensitive member whose photosensitive layer is made of an inorganic material such as amorphous silicon, and a photosensitive layer whose charge generating agent, charge transporting agent, and binder. It is roughly classified into an organic photoreceptor containing a resin.
Although these photoconductors have different manufacturing methods depending on the material and structure of the photosensitive layer, the surface of a cylindrical drum base tube made of a conductive material such as aluminum is subjected to an insulating film forming process such as anodizing. For example, in the case of a single layer type organic photoreceptor, a photosensitive layer can be formed by immersing it in a solvent in which a charge generating agent, a charge transporting agent, a binder resin and the like are dispersed in a predetermined mixing ratio. .
However, since the photosensitive layer is a thin film layer having a thickness of about several tens of μm, it is difficult to form it uniformly on the surface of the blank tube, and there is a case where a defective region where electric insulation cannot be sufficiently maintained is formed. It was. In that case, there is a problem that an accurate latent image cannot be formed in the defective area and image characteristics are deteriorated.

Therefore, in order to solve such a problem, as shown in FIG. 5, a defect inspection apparatus for detecting a current change that occurs when a defect exists in an electrically insulating object, the surface of the electrically insulating object being A comb-shaped electrode 307 disposed opposite to the OPC drum 306 having voltage, a voltage applying means 308 for applying a voltage to the comb-shaped electrode 307, and a discharge current between the comb-shaped electrode 307 and the OPC drum 306. A defect inspection apparatus 300 including a current change detection unit 309 for detecting a current change is disclosed (for example, see Patent Document 1).
According to this inspection apparatus 300, a predetermined current is applied to the voltage application means 308 while rotating the OPC drum 306, one end of which is short-circuited, around the cylindrical axis, whereby a discharge current is supplied from the comb electrode 307 to the OPC drum 306. And the presence or absence of a defect can be determined from the change in the amount of current.
JP 2003-161723 (Claims, FIG. 1)

However, although the defect inspection apparatus described in Patent Document 1 is sufficiently capable of detecting a defect, there has been a case where a problem occurs in the ground contact portion of the OPC drum 306.
More specifically, in the ground contact indicated by A in FIG. 5, for example, a flange, which is a jig necessary for mounting the device, is attached to both ends of the OPC drum 306, and a ground plate provided inside the flange In the case where one end of the OPC drum 306 is short-circuited, a method for verifying the conduction stability has not been sufficiently considered.
Further, this flange can be assembled after the defect inspection, but in that case, there is a need to conduct a continuity inspection in an actual machine, and there is a problem that productivity is lowered.

Therefore, as a result of intensive studies, the inventors of the present invention have inspected the continuity between the electrophotographic photosensitive member having a photosensitive layer on the surface of the drum base tube and the ground plate attached to the end of the drum base tube. A conductive inspection method for disposing an electrode having a predetermined shape opposite to the surface of an electrophotographic photosensitive member, and applying a voltage to the electrode to generate a discharge current, thereby generating an electrophotographic photosensitive member and a ground plate It is found from the current density of the discharge current that the presence / absence of conduction, particularly the presence / absence of conduction between the drum tube and the ground plate, and it is found that the conduction stability can be easily and reliably maintained. It has been completed.
That is, the present invention relates to an electrophotographic photosensitive member excellent in conduction stability by reliably detecting a conduction failure in a flange portion provided at an end of the electrophotographic photosensitive member before mounting the image forming apparatus. An object of the present invention is to provide a continuity testing method that can be performed.

According to the present invention, there is provided a continuity inspection method for inspecting continuity between an electrophotographic photosensitive member having a photosensitive layer on a drum base surface and a ground plate attached to an end of the drum base. A long sawtooth electrode disposed so as to face the photosensitive layer, voltage applying means for applying a voltage to the sawtooth electrode, and rotating the electrophotographic photosensitive member around a cylindrical axis A step of applying a voltage to the sawtooth electrode by the voltage applying means while rotating the electrophotographic photosensitive member by the rotating means, and an electrophotography from the sawtooth electrode. And a step of determining continuity based on the current density of the discharge current flowing toward the surface of the photosensitive member. The continuity inspection method is provided, and the above-described problem can be solved.
That is, by disposing the electrodes used in the continuity test apparatus close to the surface of the electrophotographic photosensitive member, the continuity test can be performed stably without damaging the electrophotographic photosensitive member itself. In addition, by making the shape of the electrode serrated, it is possible to stably generate a discharge phenomenon and prevent the occurrence of problems such as abnormal discharge, and an electrophotographic photosensitive member and a ground plate attached to the flange; Can be inspected stably and effectively.

Further, in carrying out the continuity inspection method of the present invention, in the continuity determination step, when the current density of the discharge current is 1.0 × 10 ⁻³ (A / m ² ) or less, it is determined that the continuity is defective. preferable.
By carrying out in this way, a simple and clear pass / fail judgment operation can be performed by unambiguously defining the criteria for continuity determination.
In the present invention, the current density of the discharge current is a value obtained by dividing the current value A (μA) injected from the electrode toward the electrophotographic photosensitive member by the surface area S (mm ² ) of the electrophotographic photosensitive member. It is defined as A / S (A / m ² ).
The step of determining the continuity can include a role as a defect inspection of the photosensitive layer. That is, when the current density of the discharge current exceeds a predetermined value, abnormal discharge has occurred in the vicinity of the photosensitive layer, and it can be determined that there is a defect on the surface of the photosensitive layer. In addition, as a determination criterion, for example, when the current density of the discharge current becomes 1.7 × 10 ⁻² (A / m ² ) or more, it can be determined that the defect is defective.

In carrying out the continuity inspection method of the present invention, it is preferable to set the rotation speed of the rotating means to a value within the range of 30 to 200 rpm.
By carrying out in this way, the continuity between the electrophotographic photosensitive member and the ground plate can be inspected both in the stopped state and in the rotating state, and the continuity stability after moving can be effectively ensured. it can. In addition, the durability can be verified in a short time by rotating at a higher speed than when forming an image.

In carrying out the continuity test method of the present invention, it is preferable to determine continuity while irradiating the photosensitive layer with light in the continuity determination step.
By carrying out in this way, the electrical conductivity of the photosensitive layer can be changed, and the generation efficiency of the discharge current can be greatly improved. As a result, the continuity test can be performed with a smaller applied voltage, and the continuity test can be performed with low power and in a short time.

Another aspect of the present invention is a continuity test for inspecting continuity between an electrophotographic photosensitive member having a photosensitive layer on the surface of a drum base tube and a ground plate attached to an end of the drum base tube. An apparatus, an elongated sawtooth electrode disposed so as to face the photosensitive layer, voltage applying means for applying a voltage to the sawtooth electrode, and an electrophotographic photosensitive member around a cylindrical axis And a rotating means for driving the electrophotographic photosensitive member to rotate the electrophotographic photosensitive member by applying the voltage to the sawtooth electrode by the voltage applying means while rotating the electrophotographic photosensitive member by the rotating means. It is a continuity test apparatus characterized by determining continuity based on the current density of the discharge current flowing toward the surface.
That is, an electrophotographic photosensitive member inspected using such a continuity testing apparatus has excellent continuity stability, and therefore, when incorporated in an image forming apparatus, it has excellent charging characteristics and has a long period of time. High conduction stability can be exhibited.

In configuring the continuity testing apparatus of the present invention, it is preferable that the electrophotographic photosensitive member and the sawtooth electrode are arranged vertically in the continuity testing apparatus.
With this configuration, it is possible to prevent the sawtooth electrode having a long shape from being deformed by its own weight, and the distance between the electrophotographic photosensitive member and the continuity inspection device can be defined with high accuracy.
In addition, it is possible to reduce the installation area of the continuity test apparatus and contribute to space saving.

In configuring the continuity testing apparatus of the present invention, it is preferable that the closest distance between the sawtooth electrode and the surface of the electrophotographic photosensitive member is set to a value in the range of 0.1 to 3 mm.
With this configuration, the electric resistance value between the sawtooth electrode and the electrophotographic photosensitive member can be controlled within a predetermined range, and the current density of the discharge current can be stabilized.

In configuring the continuity testing device of the present invention, the surface of the sawtooth electrode is preferably nickel-plated.
By comprising in this way, formation of the oxide film of the electrode surface by using for a long period of time can be prevented, and it can contribute to the lifetime improvement of an electrode.

[First embodiment]
The first embodiment of the present invention is a continuity test for inspecting continuity between an electrophotographic photosensitive member having a photosensitive layer on the surface of a drum base tube and a ground plate attached to an end of the drum base tube. A long sawtooth electrode disposed so as to face the photosensitive layer, voltage applying means for applying a voltage to the sawtooth electrode, and an electrophotographic photosensitive member around a cylindrical axis. A step of applying a voltage to the sawtooth electrode by the voltage applying means while rotating the electrophotographic photosensitive member by the rotating means, and a sawtooth shape. And a step of determining conduction based on the current density of the discharge current flowing from the electrode toward the surface of the electrophotographic photosensitive member. Hereinafter, it will be specifically described separately for each component.

1. Continuity inspection method The continuity inspection method in the present invention is a continuity inspection method for inspecting the electrical connection state between an electrophotographic photosensitive member and a ground plate provided at an end of the electrophotographic photosensitive member, A step of attaching the electrophotographic photosensitive member to the continuity inspection device, a step of rotating the electrophotographic photosensitive member by a rotating means, a step of applying a predetermined voltage to the sawtooth electrode, and the surface of the electrophotographic photosensitive member from the sawtooth electrode And a step of determining conduction based on the current density of the discharge current flowing toward.

(1) Step of Attaching Electrophotographic Photoreceptor to Continuity Inspection Device First, the continuity inspection method in the present invention is characterized by using a predetermined continuity inspection device 10 as shown in FIG. Although details of the continuity inspection device 10 will be described later, after the electrophotographic photosensitive member 11 is disposed at a predetermined position, the sawtooth electrode 20 is disposed so as to face the electrophotographic photosensitive member 11 at an interval L.
At this time, as shown in FIG. 1, the sawtooth electrodes 20 are preferably arranged so as to face each other so as to be parallel to the electrophotographic photosensitive member 11 and are arranged vertically.
That is, it is preferable that the electrophotographic photosensitive member 11 is arranged so that the cylindrical axis direction is oriented in the vertical direction, and the sawtooth electrode 20 is arranged so that the longitudinal direction is oriented in the vertical direction.
The reason for this is that by placing each of them vertically as described above, the effect of deformation such as bending due to their own weight can be eliminated and the gap width L can be accurately defined as compared with the case where they are placed horizontally. is there. Moreover, the arrangement space can be reduced, which can contribute to space saving.
The gap width L, that is, the value of the closest distance between the sawtooth electrode and the surface of the electrophotographic photosensitive member can be controlled to a desired value in relation to the discharge current. A value within the range of 3 mm is preferable.
The reason for this is that by setting the value within such a range, the value of the applied voltage can be made not more than the maximum allowable voltage of the power supply, and a stable discharge current can be obtained within a range that does not cause abnormal discharge. This is because it can be formed. However, if this gap width L becomes too large, it becomes difficult for the discharge current to flow depending on the usage environment, which may hinder the continuity test. On the other hand, if it becomes too small, the electrode may touch the surface of the electrophotographic photosensitive member depending on the processing accuracy of the sawtooth electrode, and may be damaged. Therefore, the value of the gap width L is preferably a value in the range of 0.5 to 2.5 mm, and more preferably a value in the range of 0.7 to 2.3.

(2) Step of rotating electrophotographic photosensitive member Next, a step of rotating the electrophotographic photosensitive member using a rotating means is performed. As shown in FIG. 1, the rotating means used in this step is a rotating means 40 including a power source for rotating the electrophotographic photosensitive member 11 in the cylindrical axis direction (M direction in the figure), and the rotation means 40 The shaft is attached so as to coincide with the central axis of the flange 60.
In such a rotating means, the rotation speed is preferably set to a value within the range of 30 to 200 rpm. The reason for this is that by setting the value within such a range, a continuity test can be performed at a value close to the drum rotation speed in a normal image forming apparatus, and a continuity test in a rotated state can be performed. is there. In addition, when the continuity inspection includes a defect inspection described later, the entire surface of the photoreceptor can be inspected with the position of the electrode fixed, and effective defect detection can be performed.
However, when the rotational speed becomes too high, the inspection efficiency is improved, but depending on the mounting method, the rotating shaft may vibrate and the electrode and the electrophotographic photosensitive member may come into contact with each other. On the other hand, if it becomes too slow, the inspection efficiency may decrease, or the inspection accuracy as a continuity inspection in a rotated state may decrease.
Accordingly, the range of the rotational speed is preferably set to a value within the range of 50 to 180 rpm, and more preferably set to a value within the range of 100 to 160 rpm.
Further, the rotating operation by the rotating means 40 is continuously performed in all subsequent steps.

(3) Step of applying a predetermined voltage to the sawtooth electrode Next, a step of applying a voltage to the sawtooth electrode using a voltage applying means is performed. The voltage applying means used in this step is arranged so as to be electrically connected to the sawtooth electrode 20, as shown in FIG.
The type of applied voltage can be defined by the relationship between the direction of the discharge current and the charging polarity of the photosensitive layer, but can be a power source that can apply a DC voltage, an AC voltage, or a superimposed voltage.
An ammeter 50 is connected to the voltage applying means 30. The value displayed on the ammeter 50 means the amount of discharge current flowing between the sawtooth electrode 20 and the electrophotographic photosensitive member 11, and the value of the ammeter 50 is monitored and converted into density. Thus, the electrical connection between the electrophotographic photosensitive member 11 and the ground plate 61 can be determined.

(4) Step of determining continuity Next, a step of determining the continuity between the electrophotographic photosensitive member and the ground plate is performed based on the value of the discharge current generated by the voltage applying means described above. In FIG. 1, this step is a pass / fail determination step based on the current value monitored by the ammeter 50, and is a step performed by the determination device 80.
The acceptance / rejection determination criteria set in the determination device 80 can be changed as appropriate depending on the use environment, the design conditions of the inspection apparatus, and the like. For example, the current density of the discharge current is 1.0 × 10 ⁻³ (A / m ² ) It is preferable to determine that the continuity is poor when it is equal to or less.
The reason for this is that if the value is within such a range, it is unambiguously influenced by factors such as the distance between the electrophotographic photosensitive member and the electrode, the charging characteristics of the photosensitive layer, and the like. This is because they can be distinguished from each other.
In the present invention, the current density is a value obtained by dividing the current value A (μA) injected from the electrode toward the electrophotographic photosensitive member by the surface area S (mm ² ) of the electrophotographic photosensitive member. It is defined as (A / m ² ).
Further, it is preferable to carry out the continuity determination while irradiating the electrophotographic photosensitive member 11 with light.
The reason for this is that the photosensitive layer of the electrophotographic photosensitive member has a function of generating charges by light irradiation and transporting it in the surface direction. This is because the electrical resistance value can be changed. Further, when the electrical resistance value of the photosensitive layer 12 is changed in this way, the potential difference in the gap width L in FIG. 1 is substantially reduced, so that a desired discharge can be obtained even with a relatively small applied voltage. This is because a current can be generated.
At this time, as a light source of the light to be irradiated, white light such as a fluorescent lamp may be irradiated, or a point light source having a relatively short wavelength mounted on the image forming apparatus may be used.

Further, in this determination step, defects formed in the photosensitive layer can be detected from the current density of the discharge current. The defect formed in the photosensitive layer is an abnormal region formed by foreign matters mixed in the process of forming the photosensitive layer, and a thin film region where the thickness of the photosensitive layer is extremely thin Or a thick film region where the photosensitive layer is extremely thick due to foreign matter or the like, and an exposed region where the underlying drum element tube is exposed.
Such a defect is a factor that deteriorates the image characteristics because the charging characteristics are different from other areas in the image forming process, so that an accurate latent image is not formed and is displayed as a black or white spot on the image. Become one.
In the process of conducting the continuity inspection method as in the present invention, when the sawtooth electrode 20 is opposed to the defect, the current emitted from the tip portion changes its traveling direction so as to be attracted to the defect. This is a phenomenon that occurs because the defective portion has a lower potential than other regions, and a so-called abnormal discharge phenomenon occurs. At this time, the value of the discharge current indicated by the ammeter 50 tends to increase as compared with the value of the normal discharge current. Therefore, by defining an upper limit value for the discharge current, it is possible to detect the presence or absence of defects on the surface of the electrophotographic photosensitive member and provide a higher quality electrophotographic photosensitive member.
In the case of including such a step of inspecting a defect, the acceptance / rejection determination criteria include, for example, a defect defect when the current density of the discharge current is 1.7 × 10 ⁻² (A / m ² ) or more. It is preferable to determine.
The reason for this is that if the value is within such a range, it is unambiguously influenced by factors such as the distance between the electrophotographic photosensitive member and the electrode, the charging characteristics of the photosensitive layer, and the like. This is because they can be distinguished from each other.

[Second Embodiment]
The second embodiment of the present invention is a continuity test for inspecting continuity between an electrophotographic photosensitive member having a photosensitive layer on the surface of a drum base tube and a ground plate attached to an end of the drum base tube. An apparatus, an elongated sawtooth electrode disposed so as to face the photosensitive layer, voltage applying means for applying a voltage to the sawtooth electrode, and an electrophotographic photosensitive member around a cylindrical axis A rotating means for rotating the electrophotographic photosensitive member to the surface of the electrophotographic photosensitive member by applying a voltage to the sawtooth electrode by the voltage applying means while rotating the electrophotographic photosensitive member by the rotating means. It is a continuity test apparatus characterized by determining continuity based on the current density of the discharge current which flows toward. In the following, parts common to the first embodiment will be omitted as appropriate, and will be described in order according to each component.

1. Continuity Inspection Device (1) Basic Configuration As shown in FIG. 1, a continuity inspection device 10 used in the continuity inspection method of the present invention is a long sawtooth shape disposed so as to face the electrophotographic photosensitive member 11. The electrode 20, the voltage applying means 30 electrically connected to the sawtooth electrode, the rotating means 40 for rotating the electrophotographic photosensitive member 11 around the cylindrical axis, and the electrophotographic photosensitive member from the sawtooth electrode 20. And an ammeter 50 for detecting the amount of discharge current flowing toward the body 11.
At this time, a flange 60 is attached to the end of the electrophotographic photosensitive member 11 as a jig for incorporation into the image forming apparatus. The flange 60 is provided with a ground plate 61 whose outer peripheral portion is in contact with the inner surface of the drum base tube 13 and whose central portion is in contact with the conduction pin 62. Since the conducting pin 62 is short-circuited at the other end, the ground plate 61 itself is also short-circuited, and the drum tube 13 in contact with the ground plate 61 is also short-circuited.
That is, by providing the earth plate 61, a path is formed in which electrons injected into the surface of the electrophotographic photosensitive member 11 flow into the earth from the photosensitive layer via the drum tube.
Therefore, when the earth plate and the drum base tube are electrically insulated or when the connection is insufficient, the amount of discharge current is significantly reduced.

(2) Electrode (2) -1 Shape As shown in FIG. 1, the electrode used in the present invention has a long shape as a whole, and a saw tooth having a shape similar to a saw tooth on its long side portion. It is characterized by being the electrode 20.
This is because by using an electrode having such a shape, when a predetermined voltage is applied, an electric field concentration region can be easily formed at the tip of the electrode, and electrons can be emitted uniformly and stably. It is.
FIG. 2 shows an enlarged view of the tip portion 21 of the sawtooth electrode 20. As shown in FIG. 2, as the shape of the tip portion 21, for example, it is preferable that tip portions whose planar shapes are isosceles triangles are arranged at regular intervals.
The reason for this is that, by constituting from such a shape, the electric field formed during voltage application spreads symmetrically with respect to the symmetry axis C of the isosceles triangle and is parallel to the direction indicated by the tip portion. This is because electrons can be emitted.
Further, the size of the tip portion can be appropriately changed in accordance with desired discharge characteristics. For example, the apex angle θ is preferably set to a value in the range of 5 to 20 °.
The reason for this is that by setting the value within such a range, the tip portion can have an acute angle within an allowable range of machining accuracy, and an electrode having excellent discharge efficiency can be obtained.
However, if the apex angle θ is too small, the tip may become fragile and chipped. On the other hand, if it becomes too large, the electric field density at the tip cannot be sufficiently obtained and the discharge efficiency is lowered. Therefore, the range of the apex angle θ is preferably a value within a range of 7 to 18 °, and more preferably a value within a range of 8 to 12 °.
Moreover, it is preferable to set it as the value within the range of 1-10 mm as a value of the height H of the front-end | tip part 21. FIG. This is because by setting the value within such a range, it is possible to obtain predetermined discharge characteristics while maintaining the mechanical strength.
However, if the height H is too high, it may be damaged by some mechanical impact. On the other hand, if it becomes too small, the electric field density at the tip cannot be sufficiently obtained and the discharge efficiency is lowered. Therefore, the range of the height H is preferably set to a value within the range of 1.5 to 8 mm, and more preferably set to a value within the range of 2 to 5 mm.
Moreover, it is preferable to set it as the value within the range of 0.1-2 mm as a value of the pitch space | interval D of the front-end | tip part 21. FIG. This is because, by setting the value within such a range, it is possible to form a discharge current having a predetermined current density without contacting adjacent tip portions.
However, if the pitch interval D becomes too large, the current density may decrease and the inspection accuracy of the continuity inspection may be reduced. On the other hand, if the tip portion is too small, adjacent tip portions may be short-circuited or the direction of the discharge current may be changed when the tip portion is deformed. Therefore, the range of the pitch interval D is preferably a value in the range of 0.3 to 1.8 mm, and more preferably a value in the range of 0.5 to 1.5 mm.

(2) -2 Material The material used for the sawtooth electrode 20 can be suitably selected from the viewpoints of electrical conductivity, mechanical strength, and processability. For example, stainless steel, aluminum, copper In addition, a metal material having a relatively high electrical conductivity such as silver or gold can be used. Among them, it is preferable to use a stainless alloy such as SUS304. The reason for this is that such a material is excellent in corrosion resistance while maintaining a predetermined mechanical strength. Furthermore, even when repeatedly used, an insulating film such as an oxide film is hardly formed on the surface. This is because it can be used stably over a long period of time.
Further, when such a material is used, it is preferable to further perform nickel plating on the surface. The reason for this is that by performing such a surface treatment, not only the corrosion resistance is further improved, but also the durability is improved, and an electrode that can sufficiently withstand continuous long-term use can be formed.

2. 1. Electrophotographic Photoreceptor (1) Basic Structure As shown in FIG. 1, the electrophotographic photoreceptor used in the present invention is a drum base tube 13 as a support base and a photosensitive formed on the surface of the drum base tube. An electrophotographic photoreceptor 11 comprising the layer 12 can be obtained. At this time, the photosensitive layer 12 can be a single layer type composed of a single layer, or can be a multilayer type in which different layers are sequentially laminated. In the single layer type, the charge generation agent, the charge transfer agent, and the binder resin are all contained in the same layer in the photosensitive layer, and the configuration and manufacturing method thereof can be simplified. On the other hand, in the stacked type, for example, a charge generation layer including a charge generation agent and a charge transport layer including a charge transfer agent are sequentially formed. Can be improved.

(2) Drum Base Tube A drum base tube 13 shown in FIG. 1 is a supporting base of the electrophotographic photosensitive member 11 and has a generally cylindrical shape and includes a photosensitive layer 12 on the surface thereof.
As the material, it is preferable to use a metal material having excellent electrical conductivity such as aluminum, copper, nickel, iron and the like. The reason for this is that the drum tube 13 serves as a passage path for charges generated or injected into the photosensitive layer 12, and the higher the electrical conductivity, the better the charging characteristics. is there.
It is also preferable to form a layer with low electrical conductivity such as an oxide film on the surface of the drum base tube. For example, when aluminum is used as a material, it is preferable to perform an alumite treatment. This is because the oxide film obtained by this anodic oxidation can control the flow rate of charges existing in the photosensitive layer in the ground direction and control the charging characteristics such as the charging potential to a desired value. Because.

3. Flange (1) Basic Configuration As shown in FIG. 1, the electrophotographic photosensitive member used in the present invention has a flange 60 at its end. The flange 60 is a jig that is attached so as to mesh with the gear portion on the apparatus side when the electrophotographic photosensitive member 11 is incorporated into the image forming apparatus, and the rotational power from the motor incorporated in the apparatus is It is transmitted to the electrophotographic photosensitive member 11 through the flange.
Moreover, as the external shape, as shown to Fig.3 (a)-(b), it can be set as a cylindrical shape as a whole. Such a cylindrical flange 60 is provided with a press-fitting portion 63 for press-fitting the drum base tube 13 on the outer peripheral portion thereof. The press-fitting portion 63 is designed to be slightly larger than the inner periphery of the drum base tube 13. It can be firmly fixed by being attached so as to fit inside the drum base tube 13.
Further, the press-fit portion 63 is provided with a small piece-like extension portion 64 along the outer periphery thereof. The extension portion 64 is partially formed with a notch 65 and serves as a guide when the press-fit portion 63 is fitted inside the drum base tube 13.
In addition, a rib portion 66 is provided on the press-fit portion 63 on the side facing the extension portion 64. The rib portion 66 is provided with a convex portion 66a and a concave portion 66b so as to mesh with the gear portion on the apparatus side. A gear 66c is formed on the outer peripheral portion. The rib portion 66 having such a shape is attached so as to mesh with a gear portion attached to the apparatus side, whereby predetermined rotational power can be transmitted to the electrophotographic photosensitive member.
Further, a through hole 67 is provided in the center portion of the flange 60. This through-hole 67 is a hole for passing the conduction pin 62 shown in FIG. 1, and the center position thereof coincides with the rotation center.

Further, as shown in FIG. 4, such a flange 60 includes a ground plate 61 made of a metal plate at a part thereof. The ground plate 61 has a disk shape as a whole, and is formed such that the protrusion 68 on the outer peripheral portion thereof is in electrical contact with the inner surface of the drum base tube 13 and is bent toward the center from the outer peripheral portion. The contact piece 69 is in electrical contact with the conduction pin 62 that is short-circuited to ground.
That is, the ground plate 61 serves as a terminal for electrically connecting the drum base tube 13 and the conduction pin 62, and the ground plate 61 and the drum base tube 13 are in stable contact with each other. This is an essential condition for exhibiting excellent charging characteristics.

[Examples 1 to 5]
1. Preparation of electrophotographic photosensitive member 2.7 parts by weight of X-type metal-free phthalocyanine as a charge generating substance, 50 parts by weight of a stilbene amine compound as a hole transporting agent, 35 parts by weight of an azoquinone compound as an electron transporting agent, and a binder resin As follows, 100 parts by weight of bisphenol Z-type polycarbonate resin having an average molecular weight of 30000 and 700 parts by weight of tetrahydrofuran were placed in a stirring vessel, and then mixed and dispersed by a ball mill for 50 hours to prepare a coating solution. Next, the obtained coating solution was applied by dip coating on a conductive support made of an anodized aluminum base tube having an axial length of 220 mm and a diameter of 30 mm, and then dried with hot air at 130 ° C. for 45 minutes. A single layer type electrophotographic photosensitive member having a film thickness of 30 μm was obtained.
Next, a flange obtained by resin molding and a ground plate obtained by processing and molding SUS304 are attached to the end portion of the single-layer electrophotographic photosensitive member, and the drum base tube and the ground plate are electrically connected. .

2. Continuity inspection The obtained electrophotographic photosensitive member was attached to the continuity inspection apparatus of the present invention, and adjusted so that the distance (gap width) from the sawtooth electrode was 2 mm. Further, the conducting pin that is short-circuited to the ground is passed through the through-hole of the flange, and the conducting pin and the contact piece provided on the earth plate are adjusted to be electrically connected.
Next, the electrophotographic photosensitive member was rotated at a rotation speed of 120 rpm using a rotating means.
Thereafter, after the rotation speed became constant, a voltage of 4.5 kV was applied to the voltage applying means. At this time, the amount of discharge current flowing between the sawtooth electrode and the electrophotographic photosensitive member was monitored using an ammeter.
Finally, using a determinator, the monitored current amount is converted into current density, and values set as continuity determination reference values (current value 20 μA, current density 1.0 × 10 ⁻³ A / m ^2). ) And evaluation according to the following acceptance criteria. The obtained results are shown in Table 1.
A: The current density is a value exceeding 1.0 × 10 ⁻³ A / m ² .
X: The current density is a value of 1.0 × 10 ⁻³ A / m ² or less.

3. Defect inspection For the current density obtained in the continuity inspection, the determination standard value (350 μA for current value, 1.7 × 10 ^-2 A / m ^{2 for} current density) is set as the defect inspection, and the following pass / fail criteria It evaluated according to. The obtained results are shown in Table 1.
A: Current density is a value less than 1.7 × 10 ⁻² A / m ² .
X: The current density is 1.7 × 10 ⁻² A / m ² or more.

  According to the continuity inspection method and the continuity inspection apparatus of the present invention, an electrode having a predetermined shape is disposed opposite to the surface of the electrophotographic photosensitive member, and a voltage is applied to the electrode to generate a discharge current. The presence / absence of conduction between the body and the ground plate can be determined from the current density of the discharge current, and the conduction stability can be easily and reliably maintained. Therefore, the electrophotographic photosensitive member inspected by the continuity inspection method and the continuity inspection apparatus not only improves the electrical characteristics and image characteristics in various image forming apparatuses such as copiers and printers, but also contributes significantly to economic effects. There is expected.

It is a figure for demonstrating the continuity test method and continuity test apparatus concerning this invention. It is an enlarged plan view of the tip portion of the sawtooth electrode. (A)-(b) is a schematic perspective view of a flange. It is a schematic perspective view of the ground plate attached to the flange. It is a figure for demonstrating the conventional inspection apparatus.

Explanation of symbols

10: continuity testing device, 11: electrophotographic photosensitive member, 12: photosensitive layer, 13: drum substrate (supporting substrate), 20: sawtooth electrode, 30: voltage applying means, 40: rotating means, 50: ammeter, 60 : Flange, 61: Earth plate, 62: Conduction pin, 80: Judgment machine

Claims (8)

A continuity testing method for inspecting continuity between an electrophotographic photosensitive member having a photosensitive layer on the surface of a drum tube and a ground plate attached to an end of the drum tube,
A long sawtooth electrode disposed so as to face the photosensitive layer, voltage applying means for applying a voltage to the sawtooth electrode, and driving the electrophotographic photosensitive member around a cylindrical axis And using a continuity testing device including rotating means for
Applying a voltage to the sawtooth electrode by the voltage applying means while rotating the electrophotographic photosensitive member by the rotating means;
And a step of determining continuity based on a current density of a discharge current flowing from the sawtooth electrode toward the surface of the electrophotographic photosensitive member. ^2. The continuity test according to claim 1, wherein in the continuity determination step, it is determined that the continuity is defective when a current density of the discharge current is 1.0 × 10 ⁻³ (A / m ² ) or less. Method.   The continuity inspection method according to claim 1 or 2, wherein a rotation speed of the rotating means is set to a value within a range of 30 to 200 rpm.   The continuity determination method according to claim 1, wherein in the continuity determination step, continuity determination is performed while irradiating the photosensitive layer with light. A continuity testing device for inspecting continuity between an electrophotographic photosensitive member having a photosensitive layer on the surface of a drum tube and a ground plate attached to an end of the drum tube,
A long sawtooth electrode disposed so as to face the photosensitive layer, voltage applying means for applying a voltage to the sawtooth electrode, and driving the electrophotographic photosensitive member around a cylindrical axis And rotating means for causing
While rotating the electrophotographic photosensitive member by the rotating means, a voltage is applied to the sawtooth electrode by the voltage applying means, and a discharge current flows from the sawtooth electrode toward the surface of the electrophotographic photosensitive member. A continuity test apparatus characterized by determining continuity based on density.   6. The continuity inspection apparatus according to claim 5, wherein a closest distance between the sawtooth electrode and the surface of the electrophotographic photosensitive member is set to a value within a range of 0.1 to 3 mm.   7. The continuity testing apparatus according to claim 5, wherein the electrophotographic photosensitive member and the sawtooth electrode are vertically arranged.   The continuity inspection device according to any one of claims 5 to 7, wherein a surface of the sawtooth electrode is nickel-plated.

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