JP4428527B2 - Electrophotographic photoconductor degradation acceleration test method and degradation acceleration test equipment - Google Patents

Description

  The present invention relates to a deterioration acceleration test method for an electrophotographic photoreceptor used in an image forming apparatus such as a laser printer and a copying machine, and an apparatus for performing a deterioration acceleration test.

Conventionally, there is a need for a system that quickly determines the service life of a photoreceptor. In order to meet such a demand, for example, (1) a first electrophotographic image forming member including a conductive layer and at least one photoconductive layer and having a known number of image forming cycle lifespans is prepared. (2)
A voltage is applied to form an electric field across the photoconductive layer, (3) the application of the voltage is terminated, and (4) the photoconductive layer is exposed to activating radiation to discharge the electrophotographic imaging member. (5) Measure the dark decay between the end of voltage provision and a predetermined time before exposing the photoconductive layer, or between the end of voltage provision and exposure of the photoconductive layer; 6) Record the measured dark decay of the photoconductive layer, and (7) repeat the above application, termination, exposure, measurement and recording steps until the dark decay amount reaches a maximum value which remains substantially constant, (8) The dark decay versus image formation cycle of the first and second electrophotographic image forming members is repeated by repeating the above steps with a second electrophotographic image forming member having a cycle life different from the known number of image forming cycles. (9) Maximum dark decay value of fresh electrophotographic imaging member and the above reference data. By comparing the data has been proposed a method of confirming the estimation cycle life of fresh electrophotographic imaging member (for example, see Patent Document 1.).

  However, in the case of the above-mentioned life evaluation method, since the transparent glass is pressure-bonded to the electrophotographic image forming member sample and bias is applied and irradiated with light, unlike the charging conditions by corona charging and roller charging in the electrophotographic process, It cannot be said that this is an accelerated deterioration test method that reflects actual machine conditions. In addition, the dark decay characteristics of the samples that have reached the end of their life must be known in advance. To this end, the photoconductor is mounted on the actual machine at least once and a long-time paper passing test is performed, and the cycle life of the imaging cycle It is necessary to evaluate For this reason, there has been a problem that it takes a lot of labor and time.

  As another conventional technique, there is a method of predicting the life without performing a paper passing test. That is, in this method, an electrophotographic photosensitive member (hereinafter abbreviated as a photosensitive member) rotated at a high speed, for example, 1,000 to 2,000 rpm is disposed around the photosensitive member. The life is predicted by repeating charging and exposure with a charger and exposure device. This method can be further divided into two test methods.

  One method is to fix the output of the charger and the light amount of the exposure device to preset conditions, measure the characteristics of the photoconductor after performing a test for a predetermined time, and determine the deterioration state. . The other method is to measure the potential V and the passing current I flowing through the photoconductor after exposure of the photoconductor under test, and adjust the output of the charger and the amount of light from the exposure device so that these two are always at a predetermined level. Thus, the test is performed and the characteristics of the photoconductor are measured to determine the deterioration state.

  In any of the above methods, the important point is that the amount of charge (value per unit area) Q is obtained from this passing current by measuring the passing current flowing through the photoconductor during the test. The passing current flowing through the photoconductor when printing out one sheet with an actual machine is obtained by C × V, where C (value per unit area) and electrostatic potential of the photoconductor are C × V. The total number of printed out sheets is Q / (C × V), and the life test time can be made to correspond to the number of printed sheets of the actual machine. Note that the size of the photosensitive member is a size that allows one A4 sheet to be printed on the photosensitive member without duplication.

Another important point is that the above test is an accelerated life test.
Specifically, for example, when a current passing through the sample of 5 μA / 10 cm ² is passed through the photoreceptor and tested for 20 hours (corresponding to 2 days for a test of 10 hours per day), (5/10) × 10 ⁻⁶ × The charge of 20 × 60 × 60 = 0.036 (C / cm ² ) has passed through the photoconductor. Hereinafter, the “amount of charge that has passed through the photosensitive member” is referred to as a “amount of charged charge”.
Assuming that printing is performed by A4 size paper longitudinal feed, the electrostatic capacity of the photoconductor is 100 (pF / cm ² ), the charging potential is −700 (V), and the post-exposure potential after static elimination is 0 ( V), 100 × 10 ⁻¹² × 700 = 7 × 10 ⁻⁸ (C / cm ² ) is the passing charge amount when printing out one A4 size sheet, so that 0.036 / (7 × 10 ⁻⁸ ) ≈514,000 (sheets) was printed out, which corresponds to an accelerated test.

  For the above reasons, the life test is often performed by the latter method in which the potential V and the passing current I flowing through the photosensitive member are always adjusted to a predetermined level. In this case, as can be seen from the specific calculation described above, if the current passing through the photosensitive member is constant during the test, it is easy to calculate how many printouts of the test have been performed. For this reason, a method is generally employed in which the test is performed with a constant passing current. Essentially, it is important to know the passing charge amount. Also, depending on the level of the charged potential depending on the photoreceptor, the result of the life test may differ, and it is required to perform the test with the charged potential kept constant. As described above, in order to make the charging potential and the passing current constant, a system for adjusting the high-voltage power supply output of the charger and the light amount of the exposure apparatus is necessary, and a conventional life test apparatus has been constructed to cope with this. ing.

As the conventional deterioration acceleration test, there is known a photoreceptor sample piece characteristic evaluation apparatus, for example, EPA8200 manufactured by Kawaguchi Electric Co., Ltd. as shown in the schematic configuration diagram of FIG.
As shown in FIG. 1, this characteristic evaluation apparatus is provided with an opening 3 for mounting the turntable 1 and a photosensitive sample piece. The area of the opening 3 is 19.36 cm ² (opening: 44 mm × 44 mm). ). Further, a sample piece presser plate 2 made of a conductive metal plate is attached to the turntable 1. In this apparatus, charging / exposure is repeated by the charger 4 and the exposure apparatus 5 arranged around the photosensitive member at about 1,100 rpm and can be rotated at the same speed as the actual machine. Further, the sample piece can be passed through the corona charger 4 many times by rotating at high speed. The pulse current supplied from the corona charger 4 to charge the sample piece is sent to the ammeter 6 at a predetermined detection interval, smoothed by a smoothing circuit in the ammeter 6, and then A / D converted. The data is converted by the device 8 and sent to the controller 9 for arithmetic processing. Further, the surface potential of the sample piece is monitored by a surface potential meter electrode 5 which is a monitor unit of the surface potential meter 7 arranged at a position different from the corona charger 4, and the monitored signal is detected at a predetermined detection interval. After being sent to the electrometer 7 and amplified by the amplifier in the surface electrometer 7, it is converted by the A / D converter 8 and sent to the controller 9 for arithmetic processing. Note that reference numeral 5 in the figure indicates both the exposure apparatus and the surface electrometer electrode.
By using this apparatus, a deterioration acceleration test and evaluation of characteristics such as the charging ability, charge retention performance, and sensitivity of the photosensitive member can be performed.

However, in the above-described conventional system, the two measured amounts, that is, the surface potential X and the passing current Y, and the two manipulated variables, that is, the output control value A of the charger high-voltage power supply and the output control value B of the discharge lamp light amount are mutually. Complicated control is necessary.
That is, for example, when A is increased, X and Y increase, when A is decreased, X and Y also decrease, when B is increased, X decreases, Y increases, and when B decreases, X increases. , Y decreases. For this reason, if X deviates from the target value, if A or B is operated so that X falls within the target range, another measurement amount Y changes, and disturbance is applied to Y. . On the other hand, when A or B is operated to maintain Y within the target range, this time, X changes, and very complicated control has to be performed. In addition, even if there are momentary variations in the photoreceptor surface potential and passing current during the accelerated deterioration test, these systems are not reflected in the calculation of the passing charge amount as an instantaneous error. There was room for improvement in doing.

  Therefore, in order to solve the above problem, the present inventor measures the passing potential of the electrophotographic photosensitive member by the measuring means, and controls the electric potential of the photosensitive member to be kept at a constant condition based on the measurement result, and during the test By adopting a system that calculates the passing charge amount from the measured passing current, a simple and accurate photoconductor deterioration acceleration testing apparatus has been proposed (for example, see Patent Document 2).

  Although this deterioration acceleration test device enables simple and accurate deterioration acceleration tests, recent photoconductors have a much longer life, and the proposed deterioration acceleration test device also determines the life. It takes a lot of time to test until it can be done. Accordingly, there has been a demand for the development of an accelerated deterioration test method capable of further accelerating the deterioration and judging the life in a short time.

Japanese Patent No. 3204327 (JP-A-5-1973) JP 2002-149005 A

  The present invention has been made in view of the above prior art, and provides a deterioration acceleration test method capable of determining the life of an electrophotographic photoreceptor in a short time and a deterioration acceleration test apparatus used for the evaluation thereof. Objective.

  As a result of intensive studies, the inventors of the present invention have used a charger in which a plurality of discharge wires to which a high voltage is applied are stretched only in the same direction and the casing is made of an insulating member. By increasing the amount of current flowing through the body and increasing the amount of passing charge per unit area of the photoreceptor, the life of the electrophotographic photoreceptor can be determined in a short time, and the above problems can be solved. The headline has led to the present invention. Hereinafter, the present invention will be specifically described.

That is, the present invention relates to a deterioration acceleration test method for an electrophotographic photoreceptor in which deterioration is accelerated by repeatedly executing a test cycle including a charging step using a charger and an exposure step using an exposure apparatus.
In the test cycle, the casing of the charger is formed of an insulating member, has an opening on the front side facing at least the photoconductor, and transparent insulation that transmits the irradiation light from the exposure apparatus on the back side. And an exposure unit formed of a photosensitive member, and a charger in which a plurality of discharge wires are provided in a housing parallel to the surface of the photosensitive member and stretched only in the same direction. This is a method for accelerating degradation of an electrophotographic photoreceptor.
Here, it is desirable to perform the charging step and the exposure step simultaneously.

  In the electrophotographic photoreceptor deterioration acceleration test method, it is preferable that a distance between discharge wires of the charger is 2 mm or more.

  In any one of the above electrophotographic photoconductor degradation acceleration test methods, the distance between the photoconductor surface and the discharge wire of the charger is preferably 2 mm or more.

In addition, the present invention allows a charge of the same amount as the passing charge amount that flows to the photoreceptor of the image forming apparatus to flow in a short time by the deterioration acceleration test method according to the number of sheets passed in the image forming process. An electrostatic property evaluation method for an electrophotographic photoreceptor for evaluating electrostatic properties, comprising:
The deterioration acceleration test method is the above-described deterioration acceleration test method, and relates to a method for evaluating electrostatic characteristics of an electrophotographic photoreceptor.

Furthermore, the present invention relates to an electrophotographic photoreceptor deterioration acceleration testing apparatus comprising at least a charger and an exposure device.
The charger has a casing formed of an insulating member, and has an opening on the front side facing at least the photosensitive member, and a transparent insulating member that transmits irradiation light from the exposure apparatus on the back side. A deterioration acceleration of an electrophotographic photoreceptor characterized by having a structure in which a plurality of discharge wires are provided in the housing and are parallel to the surface of the photoreceptor and stretched only in the same direction. It relates to the test equipment.

  Furthermore, the present invention relates to a method for accelerating deterioration of an electrophotographic photoreceptor, characterized in that the apparatus for accelerating deterioration of an electrophotographic photoreceptor described in any one of the above is used.

  According to the deterioration acceleration test apparatus and the deterioration acceleration test method of the present invention, the amount of current flowing through the photoconductor by corona discharge can be increased and the amount of passing charge per unit area can be increased. It becomes possible to do. Further, the operation is simple and high in accuracy, and further, it can be applied to a deterioration test of a dielectric thin film without contact or nondestructive.

As described above, according to the present invention, the charger casing is formed of an insulating member, has an opening on the front side facing at least the photosensitive member, and is transparent on the back side for transmitting the irradiation light from the exposure apparatus. A charging process and an exposure apparatus using a charger that includes an exposure unit formed of an insulating member, and in which a plurality of discharge wires that are parallel to the surface of the photoconductor and stretched only in the same direction are disposed in the housing. The test cycle including the used exposure process is repeatedly executed to accelerate deterioration, and the life of the electrophotographic photoreceptor is judged in a short time.
Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic configuration diagram of an electrophotographic photoreceptor deterioration acceleration test apparatus according to the present invention.
In FIG. 2, 10 is an exposure apparatus, 11 is a charger, 15 is a test sample stage, 14 is a test sample (photoreceptor sample piece here), 12 is a test sample holder, and 13 is a high voltage power source. FIG. 2 does not show control means for the charging device power circuit for charging the surface of the sample to be tested, or control means for the light source power circuit for irradiating the sample to be tested. Conventionally known means can be used as they are.

FIG. 3 is a schematic diagram illustrating the charger as viewed from the back side (a), the side surface side (b), and the front side (c).
The casing 11a of the charger 11 used as the charging means is formed of an insulating member, has an opening on the front side facing at least the photoconductor, and transmits the irradiation light from the exposure apparatus on the back side. The exposure unit 11b is formed of a transparent insulating member, and a plurality of discharge wires 16 are stretched in the casing 11a of the charger 11 in parallel with the surface of the photoreceptor and stretched only in the same direction. Is arranged. The tension of the discharge wire can be adjusted by the wire tension jig 17. FIG. 4 is a schematic diagram showing a wire stretch effective region (A × B region) when the charger is viewed from the front side.

  As described above, the charger used in the deterioration acceleration test apparatus of the present invention is formed of an insulating member, and the back side of the charger, for example, the central region irradiates light from the back to the deterioration region of the sample to be tested. It is possible to provide an exposure portion formed of a light-transmitting insulating member. With a member that does not transmit light, it is difficult to irradiate the surface of the photosensitive member with light during charging, and it becomes difficult to increase the amount of current to the photosensitive member under test by simultaneous charging exposure. If you want to use a neutral density filter, bandpass filter, etc., you can simply place it on the back side of the charger, but the central area of the charger is hollow, and the so-called perpendicular to the surface of the photoreceptor is hollow. In the case of the charging device, it is necessary to install the filter perpendicular to the surface of the photoreceptor through a holding jig.

The area of the exposed portion formed of an insulating member that transmits light is preferably larger than the deteriorated region of the photoconductor that is the sample to be tested. For example, all the chargers are formed of an insulating member that transmits light. It doesn't matter. If the area of the exposed area is smaller than the degradation area of the sample under test, there is a possibility that the sample under test will not be uniformly degraded, and the amount of passing charge per unit area in the degraded area will be evaluated. become unable.
Although the charger casing in the present invention is formed of an insulating member, no abnormal discharge occurs due to the insulating member, and the amount of current flowing through the photoconductor due to corona discharge can be increased. Therefore, the amount of passing charge per unit area can be increased.

The method of the deterioration acceleration test will be described with reference to FIG.
First, the surface of the photoconductor of the test sample 14 is placed on the test sample stage 15 so that the surface of the photoconductor faces the charger 11. A conductive member connected to the ground is attached to the surface of the test sample table 15. Next, the test sample 14 is pressed by the test sample presser 12 so as to be in close contact with the test sample stage 15. FIG. 5 is a top view schematically showing a state in which the test sample 14 is pressed by the test sample presser 12 and mounted on the test sample stand 15.
The test sample holder 12 used in the deterioration acceleration test apparatus is preferably an insulating member. In the conductive member, it becomes easy to be discharged to the test sample presser during charging, and the charge of the photoconductor easily moves to the test sample presser 12, so that it is difficult to increase the amount of current to the test sample.
Next, the charger 11 connected to the high voltage power source 13 performs corona discharge, and the exposure device 10 set to have a predetermined light quantity exposes the surface of the photoreceptor. A deterioration acceleration test can be performed by so-called simultaneous charging exposure in which the charging step and the exposure step are performed simultaneously.

  By changing the value of the current flowing through the test sample (photoreceptor) in the deterioration acceleration test, it is possible to change the passing charge amount per time, and thereby control the acceleration of deterioration. After the deterioration acceleration test is completed, characteristics such as charging ability, charge retention performance, and accumulated charge (residual potential) in the photosensitive layer can be measured to evaluate the deterioration state of the photoreceptor. Alternatively, the degree of deterioration of the photoconductor can be confirmed by observing the surface of the photoconductor.

The distance between the discharge wires of the charger in the deterioration acceleration test apparatus used in the above evaluation is preferably 2 mm or more. If the distance between the discharge wires is less than 2 mm, a spark discharge is generated at the same time as the start of discharge, so that a uniform corona discharge cannot be applied to the photoreceptor surface, and a deterioration acceleration test cannot be performed.
The distance between the photoreceptor surface and the discharge wire of the charger is preferably 2 mm or more. When the distance between the photoconductor and the discharge wire is less than 2 mm, spark discharge occurs simultaneously with the start of discharge, and the corona discharge is not uniformly applied to the surface of the photoconductor, making it impossible to perform the deterioration acceleration test.

Further, when used in the degradation acceleration test method of the present invention, the electrostatic characteristics of the electrophotographic photoreceptor after passing through the image forming apparatus can be evaluated in a short time.
That is, after passing a charge of the same amount as the passing charge flowing through the photosensitive member of the image forming apparatus with the number of sheets in the image forming process using the deterioration acceleration test apparatus of the present invention for a short time, By evaluating the electric characteristics, it is possible to predict the electrostatic characteristics after passing the paper by the actual machine.

  The electrophotographic photosensitive member used in the practice of the present invention has a charge generating layer, a charge transport layer formed on a conductive support, or a protective layer formed on the charge transport layer. Is used. As the conductive support, the charge generation layer, and the charge transport layer, any known ones can be used.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples.

Example 1
Using a charger having the same configuration as shown in FIGS. 3A, 3B, and 3C, the aluminum plate was corona discharged under the following conditions, and the amount of current per unit area was measured. A schematic configuration of the experimental apparatus used is shown in FIG. The evaluation results are shown in FIG.
<Charger configuration and test conditions>
Wire stretch effective region: equivalent to the A × B region in the schematic diagram of FIG. 4; 50 mm × 50 mm.
Discharge wire: Stretched only in the same direction at intervals of 10 mm in the frame (material: gold-plated tungsten wire, wire diameter: 60 μm).
Charger housing: insulating member (material: Teflon (registered trademark)).
Exposure unit provided on the back side of the housing: formed of an insulating member (material: quartz glass) that transmits light to the central region (40 mm × 40 mm) on the back side of the charger.
Distance between discharge wire and test sample (aluminum plate): 5 mm.
Discharge target area of the aluminum plate: 40 mm × 40 mm.

(Comparative Example 1)
Using a charger configured as shown in the schematic diagram of FIG. 8, the aluminum plate was corona discharged and the amount of current per unit area was measured. A schematic configuration diagram of the experimental apparatus used is shown in FIG. The results are shown in FIG. 7 together with Example 1.
<Charger configuration and test conditions>
Charger opening: 46 mm × 30 mm.
Discharge wire: Two wires are stretched in the same direction at 10 mm intervals in the frame (material: gold-plated tungsten wire, wire diameter: 60 μm).
Charger housing: conductive member (material: stainless steel).
Distance between discharge wire and test sample (aluminum plate): 10 mm.
Discharge target area of the aluminum plate: 40 mm × 40 mm.

  The present invention in which a plurality of wires are stretched only in the same direction and the material of the housing is an insulating member based on the current amount measurement results of Example 1 and Comparative Example 1, that is, the relationship of current density to applied voltage. By using this charger, it can be seen that the amount of current per unit area to the test sample surface is larger than that of the comparative example even when the same voltage applied to the discharge wire is used.

(Comparative Example 2)
Using a charger having the same configuration as shown in FIGS. 3A, 3B, and 3C, the aluminum plate was corona discharged under the following conditions, and the amount of current per unit area was measured. The experimental apparatus used has the configuration shown in FIG. The results are shown in FIG. For comparison, the results of Example 1 are also shown.
<Charger configuration and test conditions>
Wire stretch effective region: equivalent to the A × B region in the schematic diagram of FIG. 4; 50 mm × 50 mm.
Discharge wire: Stretched only in the same direction at intervals of 10 mm in the frame (material: gold-plated tungsten wire, wire diameter: 60 μm).
Charger housing: Conductive member (Material: Aluminum)
Exposure unit provided on the back side of the housing: formed of an insulating member (material: quartz glass) that transmits light to the central region (40 mm × 40 mm) on the back side of the charger.
Distance between discharge wire and test sample (aluminum plate): 5 mm.
Discharge target area of the aluminum plate: 40 mm × 40 mm.

  From the relationship of the current density with respect to the applied voltage shown in FIG. 10, the material of the charger housing is the insulating member in the present invention, so that even when the wire applied voltage is the same, compared with the case of the conductive member of the comparative example. It can be seen that the amount of current flowing to the test sample increases.

(Examples 2 to 4 and Comparative Example 3)
Except for changing the level of the discharge wire interval, the same charger configuration and test as in Example 1 were used, using the charger having the configuration shown in FIGS. 3A, 3B, and 3C as in Example 1. Under the conditions, the aluminum plate was subjected to corona discharge, and the discharge starting voltage was measured. The experimental apparatus used was the apparatus shown in FIG. The measurement results are shown in Table 1 below.

  From the results in Table 1, when the discharge wire interval is smaller than 2 mm, a spark discharge is generated at -7.3 kV. From this result, it can be seen that unless the interval between the discharge wires is 2 mm or more, corona discharge is not uniformly applied to the test sample surface, and an accurate deterioration acceleration test cannot be performed.

(Examples 5 to 9 and Comparative Example 4)
Except that the level of the distance between the test sample (aluminum plate) and the discharge wire was varied, the charger of the configuration shown in FIGS. 3A, 3B, and 3C was used in the same manner as in Example 1. The aluminum plate was corona discharged with the same charger configuration and test conditions as in Example 1, and the discharge start voltage was measured. The experimental apparatus used is the same apparatus as in Example 1. The measurement results are shown in Table 2 below.

  From the results in Table 2, it can be seen that spark discharge occurs when the distance between the test sample and the discharge wire is less than 2 mm. From this result, it can be seen that unless the distance between the test sample and the discharge wire is 2 mm or more, corona discharge is not uniformly applied to the surface of the test sample, and an accurate deterioration acceleration test cannot be performed.

(Example 10 and comparative reference experiment (Comparative Example 5))
Using the deterioration acceleration test apparatus of the present invention having the configuration shown in FIG. 2 and using the charger having the same configuration as shown in FIGS. 3A, 3B, and 3C, the deterioration is caused under the following conditions. In addition to performing an acceleration test, a comparative reference experiment was performed using an actual printer (Ricoh IPSIO Color 6500).
<Conditions for accelerated deterioration test>
Wire stretch effective region: equivalent to the A × B region in the schematic diagram of FIG. 4; 50 mm × 50 mm.
Discharge wire: Stretched only in the same direction at intervals of 10 mm in the frame (material: gold-plated tungsten wire, wire diameter: 60 μm).
Charger housing: insulating member (material: Teflon (registered trademark)).
Exposure unit provided on the back side of the housing: formed of an insulating member (material: quartz glass) that transmits light to the central region (40 mm × 40 mm) on the back side of the charger.
Distance between discharge wire and test sample (photoreceptor): 5 mm.
Sample installation: A photoconductor sample piece was placed on the test sample stage, and the size of the opening was adjusted to 40 mm × 40 mm by the test sample holder, and was in close contact with the sample stage. For the test sample holder, an insulating member (material: Teflon (registered trademark), thickness: 0.09 mm) was used.
Test sample (photoconductor): The photoconductor sample piece is of the same material and composition as the photoconductor for Ricoh IPSIO Color 6500, and the current passing through the photoconductor sample surface during the deterioration acceleration test is 92.6 μA (photoconductor). Degradation area: 40 mm × 40 mm), and illuminance set to 130 lux.
A deterioration acceleration test was performed under the above conditions.

<Conditions for Comparative Reference Experiment (Comparative Example 5)>
Printer: Ricoh IPSIO Color6500
Photoconductor: Photoconductor for Ricoh IPSIO Color 6500.
Photoconductor diameter: φ168 mm.
Capacitance of the photoreceptor: 110 pF / cm ² .
Printer development conditions: charging potential: 700 V, post-exposure potential: 100 V, between papers: A4 landscape 1.5, paper feed conditions: A4 landscape, QL: Yes, solid density of the original;
Under the above conditions, a test was conducted to actually deteriorate the photoconductor by passing paper through an actual printer.

  Under the above conditions, the passing charge amount for every 125,000 (125k) sheets passed by the actual printer, the test time until reaching the passing charge amount, and the deterioration acceleration test until reaching the corresponding passing charge amount Table 3 below shows the test time. In addition, Table 4 below shows the measurement results of the residual potential of the photoreceptor (the potential after sufficient exposure from a predetermined potential) at each test time.

From the results in Table 3, the characteristics (diameter, capacitance) of the photoconductor used for the test, and the development conditions of the printer using the photoconductor (charging potential, post-exposure potential, gap between paper, paper passing condition, QL) , The passing charge of the same amount as the passing charge amount of the actual printer at an arbitrary number of passing sheets calculated from the solid density of the original) is applied by using the deterioration acceleration test apparatus of the present invention, so that the sheet is passed using the actual machine. It can be seen that the time can be significantly reduced compared to testing.
Further, from the results shown in Table 4, if the amount of passing charge is the same, the residual potential after deterioration is almost the same. If the photoreceptor is deteriorated using the deterioration acceleration test apparatus of the present invention, the paper is actually passed. It can be seen that the characteristic value can be predicted for any number of sheets. That is, it is possible to predict the characteristic value of the actual number of sheets in an actual printer in a short time.

It is a schematic block diagram for demonstrating the characteristic evaluation apparatus used for the deterioration acceleration test of the conventional photoconductor sample piece. 1 is a schematic configuration diagram illustrating an electrophotographic photoreceptor deterioration acceleration test apparatus according to the present invention. It is the schematic diagram seen from the back side (a), side surface side (b), and front side (c) of the charger provided in the deterioration acceleration test apparatus in the present invention. It is a schematic diagram which shows the wire stretch effective area | region (A * B area | region) at the time of seeing the charger in this invention from the front side. It is the top view which showed typically a mode that the test sample was mounted | worn on a test sample stand in the deterioration acceleration test of this invention. It is a schematic block diagram of the experimental apparatus used in Examples 1-9 and Comparative Examples 1-4. 6 is a graph showing the relationship between applied voltage and current density measured in Example 1 and Comparative Example 1. 6 is a schematic diagram of a charger used in Comparative Example 1. FIG. It is a schematic block diagram of the experimental apparatus used in the comparative example 1. 6 is a graph comparing the relationship between applied voltage and current density measured in Comparative Example 2 with Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turntable 2 Sample piece pressing plate 3 Opening part 4 Charger 5 Exposure apparatus, surface potential meter electrode part 6 Ammeter 7 Surface potential meter 8 A / D converter 9 Controller 10 Exposure apparatus 11 Charger 11a Case
11b Exposure unit 12 Test sample holder 13 High-voltage power supply 14 Test sample 15 Test sample table 16 Discharge wire 17 Wire stretching jig

Claims (7)

In a method for accelerating deterioration of an electrophotographic photoreceptor in which deterioration is accelerated by repeatedly executing a test cycle including a charging step using a charger and an exposure step using an exposure apparatus,
In the test cycle, the casing of the charger is formed of an insulating member, has an opening on the front side facing at least the photoconductor, and transparent insulation that transmits the irradiation light from the exposure apparatus on the back side. And an exposure unit formed of a photosensitive member, and a charger in which a plurality of discharge wires are provided in a housing parallel to the surface of the photosensitive member and stretched only in the same direction. Method for accelerating degradation of electrophotographic photoreceptor.   The method for accelerating deterioration of an electrophotographic photoreceptor according to claim 1, wherein the charging step and the exposure step are performed simultaneously.   The method for accelerating deterioration of an electrophotographic photoreceptor according to claim 1, wherein an interval between discharge wires of the charger is 2 mm or more.   2. The deterioration acceleration test method for an electrophotographic photoreceptor according to claim 1, wherein a distance between the photoreceptor surface and a discharge wire of the charger is 2 mm or more. Evaluate the electrostatic characteristics of the photoconductor after passing the paper by passing the same amount of charge as the passing charge that flows to the photoconductor of the image forming apparatus in a short time by the deterioration acceleration test method as the number of paper passes in the image forming process. An electrostatic property evaluation method for an electrophotographic photoreceptor,
5. The method for evaluating electrostatic characteristics of an electrophotographic photoreceptor, wherein the deterioration acceleration test method is the deterioration acceleration test method according to claim 1. In an electrophotographic photoreceptor deterioration acceleration testing apparatus comprising at least a charger and an exposure device,
The charger has a casing formed of an insulating member, and has an opening on the front side facing at least the photosensitive member, and a transparent insulating member that transmits irradiation light from the exposure apparatus on the back side. A deterioration acceleration of an electrophotographic photoreceptor characterized by having a structure in which a plurality of discharge wires are provided in the housing and are parallel to the surface of the photoreceptor and stretched only in the same direction. Test equipment. An electrophotographic photoreceptor deterioration acceleration test method using the electrophotographic photoreceptor deterioration acceleration test apparatus according to claim 6.

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