JP2019174579A - Inspection device for electrophotographic photoreceptor, inspection method, and manufacturing method - Google Patents

Abstract

To provide an inspection device for an electrophotographic photoreceptor in which accuracy and stability of inspection are improved.SOLUTION: An inspection device for an electrophotographic photoreceptor comprises: charging means for charging a surface of the electrophotographic photoreceptor; surface potential measuring means for measuring surface potential of the charged electrophotographic photoreceptor; and a mechanism for adjusting oxygen concentration between the electrophotographic photoreceptor and the charging device to equal to or less than 10%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrophotographic photoreceptor inspection apparatus, inspection method, and manufacturing method.

  Electrophotographic apparatuses are widely used as copying machines, facsimile apparatuses, and printers.

  In an electrophotographic image forming process (electrophotographic process), the surface of an electrophotographic photosensitive member is charged, and an electrostatic latent image is formed on the surface of the electrophotographic photosensitive member by exposing the image with a laser or LED according to image information. Form. The electrostatic latent image is developed with toner to form a toner image on the surface of the electrophotographic photosensitive member, and the toner image is transferred to a recording material such as paper. Residual toner remaining on the surface of the electrophotographic photosensitive member without being transferred is removed by a cleaner for the electrophotographic photosensitive member, and the next image forming process is repeated.

  Examples of the electrophotographic photoreceptor include an electrophotographic photoreceptor having a photoconductive layer formed of hydrogenated amorphous silicon (hereinafter also referred to as “a-Si electrophotographic photoreceptor”). The a-Si electrophotographic photoreceptor is excellent in durability, heat resistance and environmental stability. Therefore, it is preferably used in a high-speed machine that requires high reliability.

  The quality (image quality) of an image formed in the electrophotographic process greatly depends on the uniformity of the potential characteristics of the electrophotographic photosensitive member. If the electrophotographic photosensitive member has sufficiently uniform potential characteristics, a good image can be easily obtained. Therefore, an electrophotographic photosensitive member having sufficiently uniform potential characteristics is particularly suitable for an electrophotographic apparatus aiming at higher image quality. For this reason, it is extremely important to improve the image quality to accurately and accurately inspect the uniformity of the potential characteristics of the electrophotographic photosensitive member.

  In Patent Document 1, the electrophotographic photosensitive member is smoothed over the entire area of the electrophotographic photosensitive member by smoothing uneven charging due to a change in the distance between the electrophotographic photosensitive member and the charging device during the rotation of the electrophotographic photosensitive member. A technique for accurately evaluating the characteristics of these is disclosed.

JP 2010-286612 A

  However, in the prior art, it may be difficult to measure the potential of the electrophotographic photosensitive member accurately and stably. The reason is that if the inspection device is used repeatedly, the charging device (for example, the wire or shield of the charger) is easily contaminated by the discharge product. As a result, it is considered that current flowing from the charging device to the electrophotographic photosensitive member decreases or current unevenness occurs in the axial direction of the electrophotographic photosensitive member. In addition, in order to accurately measure the potential characteristics, it is necessary to perform maintenance of the charging device, which may cause a decrease in productivity.

  In addition, when accurate characteristic inspection cannot be performed, it is difficult to accurately feed back the inspection result to the electrophotographic photosensitive member manufacturing process.

  An object of the present invention is to provide an inspection apparatus, an inspection method, and a manufacturing method for an electrophotographic photosensitive member that solve the problems in the inspection described above and improve the accuracy and stability of the inspection.

The present invention relates to an inspection apparatus for an electrophotographic photosensitive member having charging means for charging the surface of the electrophotographic photosensitive member and surface potential measuring means for measuring the surface potential of the charged electrophotographic photosensitive member.
An inspection apparatus for an electrophotographic photosensitive member having a mechanism for adjusting an oxygen concentration between the electrophotographic photosensitive member and the charging device to 10% or less.

The present invention also relates to a method for inspecting an electrophotographic photosensitive member comprising a charging step of charging the electrophotographic photosensitive member using a charging device, and a surface potential measuring step of measuring the surface potential of the charged electrophotographic photosensitive member.
In the charging step, the oxygen concentration between the electrophotographic photosensitive member and the charging unit is adjusted to 10% or less.

The present invention also provides an electrophotographic photosensitive member production process for producing an electrophotographic photosensitive member by forming a photoconductive layer on a cylindrical substrate, and an inspection process for inspecting the electrophotographic photosensitive member. In the method for producing a photoreceptor,
The method for producing an electrophotographic photosensitive member is characterized in that the inspection step is a step of inspecting the electrophotographic photosensitive member by the method for inspecting an electrophotographic photosensitive member of the present invention.

  According to the present invention, it is possible to provide an electrophotographic photoreceptor inspection apparatus, inspection method, and manufacturing method with improved inspection accuracy and stability.

Schematic which shows an example of the inspection apparatus of the electrophotographic photoreceptor of this invention. Schematic which shows an example of the laminated constitution of the electrophotographic photoreceptor of this invention. 1 is a schematic view showing an example of a deposited film forming apparatus for producing an electrophotographic photosensitive member of the present invention.

[Electrophotographic photoreceptor]
FIG. 2 is a schematic view showing an example of a layer structure of an electrophotographic photosensitive member (a-Si electrophotographic photosensitive member). The electrophotographic photoreceptor shown in FIG. 2 has a lower blocking layer 2002 formed on a cylindrical substrate (hereinafter also simply referred to as “substrate”) 2001 in order to block the injection of charges from the substrate 2001 to the photoconductive layer 2003. A photoconductive layer 2003, an upper blocking layer 2004, and a surface layer 2005 are sequentially provided thereon.

(Surface layer)
The surface layer of the a-Si electrophotographic photosensitive member is provided in order to obtain good characteristics with respect to durability against repeated use, moisture resistance, use environment resistance, and the like.

  For the surface layer, for example, a material such as amorphous silicon carbide or amorphous carbon is used.

When forming the surface layer, as the source gas, for example, a gas such as methane (CH ₄ ), ethane (C ₂ H ₆ ) acetylene (C ₂ H ₂ ) can be preferably used.

(Upper blocking layer)
In the present invention, it is preferable to provide an upper blocking layer between the photoconductive layer and the surface layer for preventing the surface charge (charged charge) of the electrophotographic photosensitive member from being injected into the photoconductive layer. The upper blocking layer is preferably based on silicon atoms, and may contain carbon atoms (C), nitrogen atoms (N), and oxygen atoms (O). Furthermore, by containing an atom for controlling conductivity, it has a function of better preventing charged charge injection.

  Examples of the atoms that control conductivity include so-called impurities in the semiconductor field. In the case of an electrophotographic photosensitive member for negative charging in which the polarity of the electrophotographic photosensitive member is negative, it is possible to use Group 13 atoms of the periodic table that give p-type conductivity.

  Examples of the Group 13 atom include a boron atom (B), an aluminum atom (Al), a gallium atom (Ga), an indium atom (In), and a thallium atom (Tl). Among these, a boron atom (B) is preferable.

(Photoconductive layer)
In the present invention, the photoconductive layer preferably has a photoconductive property that can satisfy the electrophotographic performance, and specifically, a-Si (amorphous silicon) is preferable from the viewpoint of durability and stability. .
In the present invention, when a photoconductive layer composed of a-Si is used as the photoconductive layer, in order to compensate for dangling bonds in a-Si, halogen atoms can be contained in addition to hydrogen atoms. .

  The total content (H + X) of the hydrogen atom (H) and the halogen atom (X) is 10 atomic% with respect to the sum (Si + H + X) of the silicon atom (Si), the hydrogen atom (H) and the halogen atom (X). The above is preferable, and it is more preferable that it is 15 atomic% or more. On the other hand, it is preferably 30 atomic% or less, and more preferably 25 atomic% or less.

  In the present invention, the photoconductive layer may contain atoms for controlling conductivity, if necessary. The atoms for controlling the conductivity may be contained in the photoconductive layer in a uniformly distributed state, or there are portions that are contained in a non-uniform distribution state in the layer thickness direction. May be.

  As atoms for controlling conductivity, so-called impurities in the semiconductor field can be given. That is, an atom belonging to Group 13 of the periodic table giving p-type conductivity or an atom belonging to Group 15 of the periodic table giving n-type conductivity can be used. Among atoms belonging to Group 13 of the periodic table, a boron atom, an aluminum atom, and a gallium atom are preferable. Among atoms belonging to Group 15 of the periodic table, a phosphorus atom and an arsenic atom are preferable.

The content of atoms for controlling the conductivity contained in the photoconductive layer is preferably 1 × 10 ⁻² atom ppm or more and 1 × 10 ² atom ppm or less with respect to silicon atoms (Si).

  In the present invention, the layer thickness of the photoconductive layer is preferably 15 μm or more and 60 μm or less from the viewpoint of obtaining suitable electrophotographic characteristics and economy.

  The photoconductive layer may be composed of a single layer or a plurality of layers (for example, a charge generation layer and a charge transport layer).

In forming the photoconductive layer, for example, silanes such as silane (SiH ₄ ) and disilane (Si ₂ H ₆ ) can be suitably used as the source gas for supplying silicon atoms. In addition to the above silanes, for example, hydrogen (H ₂ ) can be suitably used as the source gas for supplying hydrogen atoms.

  In addition, when a photoconductive layer such as the above-described halogen atom, atom for controlling conductivity, carbon atom, oxygen atom, nitrogen atom or the like is included, a gaseous or easily gasifiable substance containing each atom is used. What is necessary is just to use suitably as a material.

(Lower blocking layer)
In the present invention, it is preferable to provide a lower blocking layer having a function of blocking charge injection from the substrate side between the substrate and the photoconductive layer. The lower blocking layer is a layer having a function of blocking the injection of charges from the substrate to the photoconductive layer when the surface of the electrophotographic photosensitive member is charged. In order to provide such a function, the lower blocking layer should be based on the material constituting the photoconductive layer and contain a relatively large amount of atoms for controlling conductivity compared to the photoconductive layer. Is preferred.

  The atoms contained in the lower blocking layer for controlling conductivity may be contained in the lower blocking layer in a uniformly distributed state or in a non-uniform distribution state in the layer thickness direction. There may be a part that does. If the distribution concentration is non-uniform, it is preferable to contain it so that it is distributed more on the substrate side. In any case, it is preferable that atoms for controlling the conductivity are contained in the lower blocking layer in a uniform distribution in the in-plane direction parallel to the surface of the substrate from the viewpoint of achieving uniform characteristics. .

  As atoms to be contained in the lower blocking layer in order to control conductivity, atoms belonging to Group 13 or 15 of the periodic table can be used depending on the charging polarity.

  Furthermore, the adhesion between the lower blocking layer and the substrate can be improved by containing at least one kind of carbon atom, nitrogen atom and oxygen atom in the lower blocking layer.

  At least one of the carbon atoms, nitrogen atoms, and oxygen atoms contained in the lower blocking layer may be contained in a uniformly distributed state in the lower blocking layer. Moreover, although it is contained uniformly in the layer thickness direction, there may be a portion containing it in a non-uniformly distributed state. In any case, it is preferable that atoms for controlling conductivity are contained in the lower blocking layer in a uniform distribution in the in-plane direction parallel to the surface of the substrate from the viewpoint of uniform characteristics. .

  The layer thickness of the lower blocking layer is preferably 0.1 μm or more and 10 μm or less, more preferably 0.3 μm or more and 5 μm or less, from the viewpoint of obtaining suitable electrophotographic characteristics and economy. By setting the layer thickness to 0.1 μm or more, the charge injection ability from the substrate can be sufficiently obtained, and a preferable charging ability can be obtained. On the other hand, when the thickness is 5 μm or less, it is possible to suppress an increase in manufacturing cost due to an extension of the time for forming the lower blocking layer.

(Substrate)
The substrate preferably has conductivity (conductive substrate), and preferably can hold the photoconductive layer formed on the surface and the surface layer.

  As the material of the substrate, for example, aluminum, stainless steel, copper, nickel, cobalt, iron, chromium, molybdenum, titanium, or an alloy thereof can be used. Among these, aluminum is preferable from the viewpoint of workability and manufacturing cost, and an Al—Mg alloy and an Al—Mn alloy are more preferable.

(Manufacturing apparatus and manufacturing method for manufacturing an electrophotographic photosensitive member)
FIG. 3 is a schematic view showing an example of a deposited film forming apparatus for producing the a-Si electrophotographic photosensitive member of the present invention. Specifically, it is a schematic diagram illustrating an example of an electrophotographic photosensitive member manufacturing apparatus using an RF plasma CVD method using a high-frequency power source.

  This apparatus mainly includes a deposition apparatus 3100 having a reaction vessel 3110, a source gas supply device 3200, and an exhaust device (not shown) for depressurizing the inside of the reaction vessel 3110. In the reaction vessel 3110 in the deposition apparatus 3100, a conductive substrate (cylindrical substrate) 3112 connected to the ground, a substrate heating heater 3113, and a source gas introduction pipe 3114 are installed. Further, a high frequency power source 3120 is connected to the cathode electrode 3111 via a high frequency matching box 3115.

The source gas supply device 3200 is
Source gas cylinders 3221 to 2225 such as SiH ₄ , H ₂ , CH ₄ , NO, B ₂ H ₆ ,
Valves 3231 to 3235,
Pressure regulators 3261-3265,
Inflow valves 3241 to 3245,
Outflow valves 32251 to 3255 and mass flow controllers 3211 to 3215
It is composed of

  A gas cylinder filled with each source gas is connected to a source gas introduction pipe 3114 in the reaction vessel 3110 via an auxiliary valve 3260.

  Next, a method for forming a deposited film using this apparatus will be described.

  First, the substrate 3112 that has been degreased and washed in advance is placed in the reaction vessel 3110 via a cradle 3123. Next, an exhaust device (not shown) is operated to exhaust the reaction vessel 3110. While viewing the display of the vacuum gauge 3119, when the pressure in the reaction vessel 3110 reaches a predetermined pressure (for example, 1 Pa or less), electric power is supplied to the substrate heating heater 3113. Then, the base 3112 is heated to a predetermined temperature (for example, 50 ° C. to 350 ° C.). At this time, an inert gas such as Ar or He can be supplied from the gas supply device 3200 to the reaction vessel 3110 and heated in an inert gas atmosphere.

  Next, a gas used to form a deposited film is supplied from the gas supply device 3200 to the reaction vessel 3110. That is, if necessary, the valves 3231 to 3235, the inflow valves 3241 to 3245, and the outflow valves 3251 to 3255 are opened, and the flow rate is set to the mass flow controllers 3211 to 3215. When the flow rate of each mass flow controller is stabilized, the main valve 3118 is operated while viewing the display of the vacuum gauge 3119 to adjust the pressure in the reaction vessel 3110 to a predetermined pressure. When a predetermined pressure is obtained, the high frequency matching box 3115 is operated simultaneously with the application of high frequency power from the high frequency power source 3120. Then, plasma discharge is generated in the reaction vessel 3110. Thereafter, the high-frequency power is quickly adjusted to a predetermined power to form a deposited film. When the formation of the predetermined deposited film is finished, the application of the high frequency power is stopped, the valves 3231 to 3235, the inflow valves 3241 to 3245, the outflow valves 3251 to 3255, and the auxiliary valve 3260 are closed, and the supply of the raw material gas is finished. At the same time, the main valve 3118 is fully opened, and the reaction vessel 3110 is evacuated to a pressure of 1 Pa or less.

  The formation of the deposited layers is completed as described above. When a plurality of deposited layers are formed, the above procedure is repeated again to form each layer. The bonding region can also be formed by changing the raw material gas flow rate, the pressure, and the like to the conditions for forming the photoconductive layer in a certain time.

  After all the deposited films are formed, the main valve 3118 is closed, the leak valve 3117 is opened, an inert gas is introduced into the reaction vessel 3110 to return to atmospheric pressure, and then the substrate 3112 is taken out.

(Electrophotographic photoconductor inspection device)
The electrophotographic photosensitive member produced by the apparatus shown in FIG. 2 is then subjected to potential measurement by an electrophotographic photosensitive member inspection apparatus to evaluate whether the potential characteristics are satisfied.

  FIG. 1 is a schematic view showing an example of an inspection apparatus for an electrophotographic photosensitive member according to the present invention. Hereinafter, an outline of the electrophotographic photoreceptor inspection apparatus will be described with reference to FIG.

  A cylindrical electrophotographic photoreceptor 1001 is rotated by a rotation drive mechanism (not shown). The surface of the rotating electrophotographic photosensitive member 1001 is charged by a charging device having a charger 1002 disposed on the outer peripheral surface of the electrophotographic photosensitive member 1001. Thereafter, the surface of the electrophotographic photoreceptor 1001 is irradiated with exposure light 1003 by an image exposure apparatus (not shown) to form an electrostatic latent image on the surface of the electrophotographic photoreceptor 1001.

  Thereafter, the pre-exposure device 1004 irradiates the surface of the electrophotographic photoreceptor 1001 with pre-exposure light, and the surface of the electrophotographic photoreceptor 1001 is neutralized. The surface potential of the electrophotographic photoreceptor 1001 is measured by a surface potential meter 1005. A plurality of surface electrometers may be installed in the circumferential direction according to the type of measurement. Further, a configuration in which nitrogen gas is supplied from the nitrogen gas supply mechanism 1006 between the electrophotographic photosensitive member 1001 and the charger 1002 can be employed. The oxygen concentration can be measured with an oxygen concentration meter 1008. Nitrogen gas to be supplied can be supplied from a cylinder 1008 or the like, and the oxygen concentration between the charger and the electrophotographic photosensitive member can be adjusted by adjusting the flow rate via the flow meter 1009. is there.

  With the above configuration, stable potential measurement is possible.

Repeated use an inspection apparatus, discharge products such as NO _x that occurred with the discharge by the charger and the charger wire, attached to the shield portion, which may result in deposition. In such a state, the discharge in the vicinity of the wire becomes unstable, the current flowing toward the electrophotographic photosensitive member becomes uneven, and the characteristics of the electrophotographic photosensitive member photoconductor may not be evaluated correctly. In order to correctly evaluate the characteristics of the electrophotographic photosensitive member, it is necessary to periodically clean the charger or replace it depending on the case, resulting in a decrease in productivity of the electrophotographic photosensitive member.

With the introduction of the charger and nitrogen gas between the electrophotographic photosensitive member, since the oxygen concentration is reduced, discharge products such as NO _x produced by the discharge is reduced, the adhesion to such a charger wire and shield Therefore, the discharge is easily stabilized even after repeated use. In particular, when the oxygen concentration between the charger and the electrophotographic photosensitive member is 10% or less, the effect of the present invention is sufficiently obtained.

  Hereinafter, the present invention will be described in detail by way of examples and comparative examples.

[Example 1 and Comparative Example 1]
As the substrate, an aluminum cylindrical substrate having a length of 381 mm, a thickness of 3 mm, and an outer diameter of 84 mm was prepared. A deposited film was formed on the substrate under the conditions shown in Table 1 using the apparatus shown in FIG. 2 to produce a negatively charged electrophotographic photosensitive member.

  The produced electrophotographic photosensitive member was attached to the inspection apparatus of FIG. 1 and inspected.

  The output value of the high voltage power supply (Model 610E, manufactured by Trek Japan) connected to the charger was adjusted, and the primary current was set to -500 μA. In addition, a surface potential meter (Model 344, manufactured by Trek Japan Co., Ltd.) was used as the surface potential measuring device, and as shown in FIG. 1B, nine units were arranged at 30 mm intervals in the axial direction of the electrophotographic photosensitive member to measure the potential. Went. For the output of the surface electrometer, 40 data for one rotation of the electrophotographic photosensitive member were collected using a data recorder (Yokogawa Electric Corporation, DL750). The collected data was averaged to calculate 9 points of axial data.

  The ratio between the maximum value and the minimum value of the measured data at 9 points in the axial direction was taken as the initial measurement value.

  Next, as shown in FIG. 1B, the nitrogen gas is supplied between the charger and the electrophotographic photosensitive member from the nitrogen gas supply mechanism, and the flow rate is adjusted, so that the charging device and the electrophotographic photosensitive member are adjusted. The oxygen concentration was adjusted to 5%. In this state, the primary current of the high voltage power source was set to -1000 μA, and continuous charging was performed for 100 hours. After continuous charging, the potential was measured in the same manner as when the initial measured value was measured, and the measured value was obtained after continuous charging. The value obtained by dividing the measured value after continuous charging by the initial value was taken as the evaluation value.

  Next, after replacing the charger with a new one, evaluation values were obtained in the same procedure as for the 5% condition even when the oxygen concentration was 7, 10, and 13%. The conditions under which the oxygen concentration was 5, 7, 10, and 13% were defined as Examples 1-1, 1-2, 1-3, and Comparative Example 1-1, respectively.

  In Comparative Example 1-2, after initial measurement values were measured, continuous charging was performed for 100 hours under a condition in which nitrogen was not passed between the electrophotographic photosensitive member and the charger. Examples 1-1 to 1-3, Comparative Example Evaluation values were calculated in the same manner as in 1-1. The results were obtained by relative evaluation when the evaluation value of Comparative Example 1-2 was 1, and compared as potential unevenness relative values. The smaller the potential unevenness relative value, the better the result. It was determined that the effect of the present invention was obtained when the potential unevenness relative value was 0.7 or less. The results are shown in Table 2.

  From Table 2, it can be seen that as the oxygen concentration between the charger and the electrophotographic photosensitive member decreases, the potential unevenness relative value decreases.

  This is probably because the discharge product adhering to the charger is reduced due to the lower oxygen concentration. In the present invention, it was judged that the effect was sufficiently obtained when the oxygen concentration was 10% or less.

  In this embodiment, the nitrogen gas is allowed to flow between the charger and the electrophotographic photosensitive member. However, the nitrogen gas may be allowed to flow so as to adjust the oxygen concentration in the entire inspection apparatus.

  Further, the nitrogen gas may be supplied from a nitrogen generator or the like.

DESCRIPTION OF SYMBOLS 1001 Electrophotographic photoreceptor 1002 Charger 1003 Image exposure light 1004 Pre-exposure light device 1005 Surface potential meter 1006 Gas supply mechanism 1007 Oxygen concentration meter 1008 Gas cylinder 1009 Flow meter

Claims (7)

In an inspection apparatus for an electrophotographic photoreceptor having a charging means for charging the surface of the electrophotographic photoreceptor, and a surface potential measuring means for measuring the surface potential of the charged electrophotographic photoreceptor,
An inspection apparatus for an electrophotographic photosensitive member, comprising: a mechanism for adjusting an oxygen concentration between the electrophotographic photosensitive member and the charging device to 10% or less.   2. The mechanism for adjusting the oxygen concentration between the electrophotographic photosensitive member and the charging device to 10% or less is a mechanism for supplying nitrogen gas between the electrophotographic photosensitive member and the charging device. The inspection apparatus for an electrophotographic photosensitive member as described.   The electrophotographic photosensitive member inspection device according to claim 1, wherein the charging device includes a charger having a wire and a shield. In a method for inspecting an electrophotographic photosensitive member comprising a charging step of charging the surface of the electrophotographic photosensitive member using a charging means, and a surface potential measuring step of measuring the surface potential of the charged electrophotographic photosensitive member,
In the charging step, an oxygen concentration between the electrophotographic photosensitive member and the charging device is adjusted to 10% or less.   The electron according to claim 4, wherein an oxygen concentration between the electrophotographic photosensitive member and the charging device is adjusted to 10% or less by supplying nitrogen gas between the electrophotographic photosensitive member and the charging device. Inspection method of photographic photoreceptor.   The method for inspecting an electrophotographic photosensitive member according to claim 4, wherein the charging device includes a charger having a wire and a shield. In an electrophotographic photosensitive member production process for producing an electrophotographic photosensitive member by forming a photoconductive layer on a cylindrical substrate, and an inspection method for inspecting the electrophotographic photosensitive member. ,
The method for producing an electrophotographic photosensitive member, wherein the inspection step is a step of inspecting the electrophotographic photosensitive member by the method for inspecting an electrophotographic photosensitive member according to any one of claims 4 to 6. .

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