JPS6033581A - Fatigue evaluation device for electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the measurement precision of variation in the elelctric characteristics of a photosensitive body due to repeated use by arrnging under a condition to select an electrostatic charger, exposure light source, destraticization electrode, destaticization light source, light source for exposure before charging, and surface potential measuring probe at the circumference of the photosensitive body. CONSTITUTION:The grounded photosensitive body 1 to be tested is charged by the electrostatic charger 2 and its charging potential is measured by the 1st surface electrometer prove 31. Then, the photosensitive body is exposed by using the 1st exposure light source 41 and the potnetial after the exposure is measured by the 2nd surface potential electrometer prove 32. Then, destaticization is carried out by the discharge from the destaticization electrode 5 or exposure from the light source 6 for optical destaticization and then the potential after the destaticization, i.e. a remaining potential is meausred by the 3rd surface electrometer probe 33. Then, exposure before charging is carried out by the 2nd exposure light source 42 lastly and the evaluation in the 2nd cycle is entered successively. Thus, the easy-to-use dedicated evaluation device which has high precision and good reproducibility and facilitates a change in evaluation condition is obtained.

Description

Detailed Description of the Invention [Technical Field to which the Invention Pertains] The present invention is directed to quantitatively measuring and evaluating changes in electrical characteristics during repeated use of electrophotographic photoreceptors, thereby preventing deterioration in the quality of copied or printed images. In particular, the present invention relates to a fatigue evaluation device for an electrophotographic photoreceptor that indirectly measures a decrease in density and background smudge.

[Prior art and its problems]

Such an evaluation can be carried out by performing actual copying six times using a real copying machine and evaluating the images, or by installing a surface electrometer probe at the developing section of an actual electrophotographic device, and measuring the voltage corresponding to the dark and light areas of a predetermined document. It is known that this is done by repeatedly measuring case changes and using the degree of change as a guide for evaluation. However, in the former case, many process factors other than the unique characteristics of the photoconductor are integrated, such as development characteristics, transfer characteristics, discharge characteristics such as charging, static neutralization, transfer, and separation, and temperature fluctuations within the electrophotographic device. Therefore, it is not necessarily suitable as a means for evaluating the fatigue of a photoreceptor, and it also damages the surface of the photoreceptor during development, cleaning steps, etc., and significantly reduces its commercial value. In the latter case, the evaluation conditions are generally fixed, making it difficult to evaluate the photoreceptor characteristics from multiple angles, and also having great difficulty in maintaining and managing the evaluation conditions that have been set, making it difficult to repeat reproducibility. It has inferior disadvantages.

[Purpose of the invention]

In view of this, it is an object of the present invention to provide a dedicated photoconductor fatigue evaluation device that is highly accurate, has good reproducibility, is easy to change evaluation conditions, has good operability and maintainability, and is easy to use.

[Key points of the invention]

The fatigue evaluation device according to the present invention includes a charger, a first exposure light source, a neutralization electrode, a static elimination light source, and a second exposure light source arranged in this order around the photoreceptor to be tested. After a plurality of surface potential measurement probes are arranged, depending on the case, the relative position of each of the electrodes and the static elimination light source can be changed except for one or the second exposure light source, and each of the exposure light sources and the static elimination light source has its own light intensity. Alternatively, the above object can be achieved by attaching a filter that changes the spectral characteristics.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, in which a grounded photoreceptor 1 to be tested is charged by a charger 2, and then the charged potential is measured by a first surface electrometer probe 31. Next, after being exposed by the first exposure light source 41, the potential after exposure is measured by the second surface potential detection probe 32. Next, after the static electricity is removed by discharge from the removal electrode 5 or exposure from the light source 6 for optical static removal, the potential after static removal, that is, the residual potential, is measured by the third surface potentiometer probe 33 of e=#lL4 waterfall. Finally, a pre-charging exposure is performed by the second exposure light source 42, and then the second cycle evaluation begins.

Note that the second destination light source 42 is used for exposure before charging in the actual machine, so in other cases it is removed or does not emit light. Both the static eliminator electrode 5 and the static eliminator light source 6 can be activated.

The two U source light sources 41 and 42 and the static elimination light source 6 are each equipped with a neutral filter to adjust the light intensity to a predetermined value, and are also equipped with interference filters and color filters to selectively irradiate light with specific spectral characteristics. It is possible to attach various filters such as glass filters.

Figure 2 shows the results of measuring the amount of variation in the charging potential measured by the probe 31 several times on the same photoreceptor after repeating a predetermined number of cycles using this device, and shows how the amount of variation in the charging potential can be repeatedly reproduced. It evaluates gender. Second
As shown in the figure, the results of six measurements were within ±1 (11) of the average value, indicating excellent reproducibility.

Exposure g! in Figure 1! 41, static elimination electrode 5, static elimination light source 6,
The position of the pre-charging exposure light source 42 is variable, and by arranging it so that its relative position to the charger 2 is equal to that of the copying machine in which the tested photoreceptor is used, the degree of fatigue in the copying machine can be determined. things are possible.

In the embodiment shown in FIG. 3, only one surface potential measuring probe 34 is placed immediately after the exposure light source 41. In the embodiment shown in FIG. Here, the neutral filter 7 attached to the exposure light source 41 can be switched to three or more types, and the amount of transmitted light of each is set to the amount of light necessary to obtain the charged potential, the post-exposure potential, and the post-static potential. Therefore, the charged potential, the post-exposure potential, and the post-discharge potential can be measured using only one probe 34.

〔Effect of the invention〕

In the present invention, the photoreceptor is not mounted on a real copying machine, but a charger, an exposure light source, a removing electrode, a static removing light source, a pre-charging exposure light source, and a surface potential measurement probe are arranged around the photoreceptor under selectable conditions to reduce fatigue. This evaluation device makes it possible to measure and evaluate the amount of variation in the electrical characteristics of a photoreceptor due to repeated use with high precision and good repeatability. The process layout and conditions are configured to be approximately the same as those of the copying machine in which the photoreceptor is applied, and fatigue is caused by the difference in potential under light intensity irradiation corresponding to black paper, intermediate density, white paper, etc. in the copying machine. By configuring the structure to evaluate the degree of change, it is possible to accurately measure the deterioration of image quality during continuous copying due to fatigue of the photoreceptor when actually installed in a copying machine, by corresponding to the degree of change in the electrical characteristics of the photoreceptor. Furthermore, by using multiple surface potential measurement probes, it is possible to determine the charged potential, post-exposure potential,
The potential after static electricity removal was measured at the same time, making it possible to measure repeated fluctuations in the light attenuation characteristics of the photoreceptor.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram of each part of the device according to one embodiment of the present invention, Fig. 6-2 is a diagram showing the results of repeated measurements of the amount of variation in charge potential using the same, and Fig. 3 is a diagram showing the results of repeated measurements of the amount of fluctuation in charge potential using the same. It is a layout diagram of each part of the device. 1... Photoreceptor to be tested, 2... Charger, 31, 32, 33, 34... Surface potential measurement probe,
41.42...Exposure light source, 5...Removal electrode, 6...
Static elimination light source. 7- Figure 1

Claims (1)

[Claims] 1) A charger, a first exposure light source, a neutralizing electrode, a static eliminating light source, and a second exposing light source are placed around the photoreceptor to be tested in this order, and one or more of them are followed by surface potential measurement. The probe is arranged so that the relative position of each of the electrodes and the neutralization light source, except for one or the second exposure light source, can be varied depending on the case, and each of the exposure light sources and the static elimination light source is equipped with a filter that changes the light intensity or spectral characteristics. 1. A photoreceptor fatigue evaluation device for electrophotography, characterized in that: