JP2886749B2 - Electrophotographic photoreceptor and electrophotographic process control method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member comprising a conductive supporting member and a photoconductive layer, and an electrophotographic method using the photosensitive member.

[0002]

2. Description of the Related Art The surface potential of a photoreceptor greatly changes depending on environmental conditions. For example, in the case of an OPC photosensitive member, the potential was lowered by 100 to 150 V compared with the potential at normal temperature due to the temperature dependence of the mobility of the photocarrier in a low temperature environment. In the case of the Se photoconductor, the potential increases at a low temperature (50 v) and decreases at a high temperature (50 to 100) due to the temperature dependence of the amount of thermally excited carriers generated in the photosensitive layer.
v). In the case of an OPC photoreceptor, as the number of copies increases, the photosensitive layer undergoes film thickness reduction due to mechanical stress (the polishing effect of a cleaner blade or transfer paper), and the film thickness decreases. But tended to decrease gradually. These changes in surface potential have caused large changes in the image quality to be copied, such as a decrease in density, and the amount of toner developed and consumed has changed, causing an uneconomical phenomenon. On the other hand, also in the developer, the amount of triboelectric charge of the toner changes due to the environmental change, and in a low-temperature and low-humidity environment, the image density may be reduced by increasing the amount of charge (0.8 ± 0.
About 4), in a high-temperature and high-humidity environment, an increase in image density, a deterioration in gradation reproducibility, an increase in toner consumption, and the like were caused by a reduction in the amount of charge.

Even when the copy mode is changed, there are cases where the image quality difference between the modes disappears or the purpose such as reduction of toner consumption cannot be achieved due to these unstable factors. Various process controls have been employed to solve these problems. This can be explained in detail, for example, by providing a surface electrometer in a copying machine, detecting the surface potential of the photoconductor at appropriate times, and optimally controlling the output of the charger and the copy lamp voltage according to the result, or a photoconductor. An image of a standard white plate or the like is printed on it, visualized with toner, the density of this toner image is detected by an optical sensor, and the output of the charger, the toner density of the developer, the developing bias This is a method for optimally controlling the voltage and the copy lamp voltage. In the above-described system, there is a problem in the detection accuracy due to a decrease in the temperature characteristic of the optical sensor for detection and the amount of light emitted due to contamination. It is proposed that the temperature characteristics be mitigated by a temperature compensation circuit, and that the decrease in the amount of light emission due to contamination should be periodically increased by increasing the load power or correcting the sensitivity of the sensor to increase the amount of light from the light emitting element. It has been proposed to mitigate by providing a circuit. However, these are expensive and extremely disadvantageous economically. On the other hand, as a method of compensating for the deterioration of the detection accuracy due to the temperature characteristics and the decrease in the amount of emitted light due to contamination, a method of referring to the detection result of the toner non-adhered portion on the photoconductor and using this as a reference is also proposed. Have been. This method uses a value obtained by dividing the detection result of the toner patch portion by the detection result of the non-toner-attached portion as a signal, and utilizes the fact that the toner-non-adhered portion is constant and does not change. Many photoconductor materials have no absorption coefficient for near-infrared light and are transparent. Therefore, detecting the non-toner-attached portion with light of such a wavelength means observing the surface of the photosensitive drum. The surface of the photoreceptor tube is protected by the photoreceptor material and does not change during the life of the photoreceptor. This method can be effective at relatively low cost.

[0004]

However, in each of these methods, there are two factors that further deteriorate the detection accuracy. That is, one is the instability of the distance between the surface of the photosensitive member to be observed and the detection sensor, and the other is the instability of the distance between the photosensitive member and the charger.

(1) When the detection sensor is fixed and held, the deflection when the photosensitive member is rotating is about ± 75 μm. Therefore, the above-mentioned distance changes in a width of 150 μm. FIG. 3 shows the concentration 1.
This is a result of detecting a toner patch of 0 by an optical sensor.
The fit between the base tube and the flange was adjusted so that the photoreceptor had a large rotational runout, and the photoreceptor was set so that the toner patches could be detected at various distances. The horizontal axis shows the amount of change in the distance between the photoconductor and the detection sensor, and the vertical axis shows the optical density conversion value of the detection result. 1.
It turns out that it becomes about 0 ± 0.2. Such errors are unacceptably precise for the purposes of the process control described above.

(2) FIG. 4 shows the change in the distance between the surface of the photosensitive member and the charger, on the horizontal axis, from the measurement result of the fluctuation of the rotation of the photosensitive member and the measurement result of the surface potential for one rotation of the photosensitive member. It is the figure which took the vertical axis. From this figure, it is understood that the fluctuation of the surface potential is about 15 to 20 V when the distance change amount is 150 μm. This potential fluctuation corresponds to a density difference of 0.1 to 0.2 when converted to image density. Such an effect causes an error when a toner patch is created for process detection. (1) Similarly, the accuracy is completely unacceptable for the purpose of the process control.

[0007] The deflection which is caused by the deflection of about ± 50 μm caused by the processing accuracy of the photoreceptor tube itself and ± 50 μm caused by the processing accuracy of the photoreceptor mounting flange itself.
This is due to the degree of deflection and the degree of deflection of about ± 100 μm generated with the accuracy of fitting when assembling them. Reducing the run-out by increasing the processing accuracy increases the cost significantly and is extremely uneconomical. If the process control is performed with such accuracy, the result cannot be said to be representative of the state of the entire system. The resulting image quality becomes unstable or damages the photoreceptor due to abnormal process control, or the toner concentration increases, causing normal triboelectric charging of the toner. Since the charge cannot be applied, fog is generated due to the generation of the weakly charged toner, and furthermore, the toner is scattered, thereby contaminating the inside of the copying machine, sometimes causing serious results. It is also possible to adopt a method such as controlling the process by increasing the number of detections and calculating the average value.However, it takes a long time to impair the original copy productivity of the copying machine or to remove a large amount of toner. There is a problem that it becomes extremely uneconomical to use.

An object of the present invention is to provide an electrophotographic photosensitive member capable of detecting a density of a toner patch with high accuracy.
Another object of the present invention is to provide an electrophotographic method for performing accurate process control using the photoconductor.

[0009]

In order to achieve the above object,
The electrophotographic photoreceptor according to claim 1 according to the present invention,
Form an optically detectable mark on the conductive support member surface
And a photoconductor for electrophotography comprising a photoconductive layer formed thereon.
Wherein the mirror-ground surface of the conductive support member is
The surface is roughened so that the reflectance of the surface state is reduced.
It is characterized by forming a crack .

The electrophotographic photosensitive member according to claim 2 of the present invention.
If the selenium-based photoreceptor, the mark in the image area,
Alternatively, in the case of an OPC photosensitive member, it is formed in a non-image area.

According to a third aspect of the present invention, there is provided an electrophotographic process control method including an electrophotographic photosensitive member, wherein the synchronous signal generates a synchronous signal in response to rotation of the photosensitive member. Generating means , based on this synchronization signal
Seeking always determined position on the photosensitive member Te, decided this always
A toner patch is created at the determined position , an image density of the toner patch is detected, and parameters of the electrophotographic process are corrected based on the detected image density.

[0012]

According to a fourth aspect of the present invention, there is provided the present invention.
An electrophotographic process control method including the electrophotographic photosensitive member described above includes a synchronous signal generating unit that generates a synchronous signal in response to rotation of the photosensitive member, and based on the synchronous signal , a photosensitive signal is generated. Seeking a constantly determined area on the body , this always determined
Forming an electrostatic latent image in the selected area , detecting the surface potential of the electrostatic latent image, and correcting the parameters of the electrophotographic process based on the detected surface potential.

An electrophotographic process according to claim 5 of the present invention.
In the control method, the synchronizing signal generating means according to claim 3 or 4 uses the electrophotographic photoconductor according to claim 1 and detects the mark during rotation of the photoconductor. It is a means for obtaining a rotation synchronization signal.

An electrophotographic process according to claim 6 of the present invention.
In the control method, the synchronizing signal generating means according to claim 3 or 4 uses an electrophotographic photosensitive member having a mark formed on a rotating member that rotates in synchronization with the photosensitive member, and the rotating member rotates while the photosensitive member is rotating. Preferably, the means is a means for obtaining a synchronization signal of the rotation of the photoconductor by detecting the mark.

An electrophotographic process according to claim 6 of the present invention.
In the control method, when the synchronizing signal according to claim 3 or 4 cannot be detected, a warning display, setting of an electrophotographic process parameter for lowering the density of a copied image, invalidation of process control, and a copy operation are performed. At least one of the prohibition processes is performed.

[0016]

According to the electrophotographic photoreceptor of the present invention , mirror polishing is performed.
The reflectance decreases with respect to the conductive support surface
Since the mark was formed by roughening, the upper part of the mark
Even if the surface is covered with a photoconductive layer, the mark and the conductive support
Can be detected with a large S / N ratio to the surface, under the photoconductive layer.
The provided mark can be optically accurately and reliably detected. Ma
Also, the mark will be protected by the photoconductive layer. Also
By detecting the mark, a signal synchronized with the rotation of the photoconductor is generated.
The signal can be reliably detected and its signal can be obtained. But
Therefore, based on this mark detection, the toner patch (or
Is an electrostatic latent image), the toner patch (or static
Electrostatic latent image) is always in the same area on the photoreceptor,
Can be formed. Therefore, the problems (1) and (2) described above , that is , the problem of the instability of the distance between the surface of the photosensitive member to be observed and the detection sensor and the problem of the instability between the photosensitive member and the charger are solved. .

When the density of the toner patch is detected, if the mark is formed on the image portion, the detection can be shared by an optical sensor for detecting the density of the toner patch, and a cost reduction effect is produced. The element that determines whether the mark is formed on the image portion or the non-image portion is the material of the photoreceptor. In the case of a selenium-based photoconductor in which a mark on the support member does not appear in an image, the mark is formed in an image portion. However, in the case of an OPC photoconductor in which a mark appears in an image, the mark is formed in a non-image portion.

Using such a photoreceptor, before or after performing the electrophotographic process,
By detecting a mark, a rotation synchronizing signal of the photoconductor is obtained, and a toner patch (or an electrostatic latent image) is formed based on the signal, and the image density (or surface potential) of the toner patch is formed.
Is detected, and the process parameters are corrected based on this . Also, when using a photoconductor in which a mark is formed on a rotating plate that rotates synchronously with the photoconductor, a rotation synchronization signal of the photoconductor is obtained by detecting the mark, and a toner patch ( or Create an electrostatic latent image)
(Or surface potential) to correct the process parameters. The correction of the process parameters
Switch or electrostatic latent image detection result and the density or
Location, for example, based on comparison with the density or potential of the non-image area.
Good.

If the mark cannot be detected, a warning is displayed on an operation panel or the like to notify the user of the abnormality. Alternatively, the operation of the process control is prohibited, that is, the detection of the process information by the creation of the toner patch (electrostatic latent image) and the correction of the electrophotographic process parameter based on the result are not performed. Alternatively, the copying operation is prohibited. By these processes, the erroneous mounting of the photoconductor is prevented, and the photoconductor having a defective mark and a different photoconductor are eliminated, and a predetermined performance is ensured.

[0020]

1 is a schematic sectional view of a copying machine for explaining the present invention.

Reference numeral 1 denotes a photoreceptor having a thickness of 2 mm and a diameter of 100
A photoconductive layer 1b is laminated on an aluminum tube 1a as a conductive support member having a length of 340 mm. The photoconductive layer 1b is made of an organic semiconductor material in which a charge generation layer is uniformly applied to a thickness of 0.5 μm and then a charge transport layer is evenly applied to a thickness of 34 μm. Reference numeral 2 denotes a charger, which was provided with a discharge electrode made of a tungsten oxide wire having a diameter of 70 μm, a stainless steel shield electrode surrounding the discharge electrode, and a screen grid electrode formed by etching a stainless material having a thickness of 0.1 mm. Scorotron charger. The high voltage applied to the grid electrode is variable in output based on the signal from cpu13. Reference numeral 3 denotes an optical system for illuminating the original on the original table and forming an image of the reflected light on the photosensitive member. Reference numeral 4 denotes a developing device for visualizing the electrostatic latent image formed on the photoconductor with toner. Reference numeral 5 denotes a transfer charger for transferring the toner image on the photoconductor to the transfer paper 6. The toner image transferred to the transfer paper 6 is heated and fixed by the fixing device 7 and discharged out of the apparatus. Reference numeral 17 denotes a means for detecting the temperature in the copying machine, which uses a thermistor. Reference numeral 9 denotes a standard white plate, which is printed on a photoreceptor at the time of forming a toner patch, visualized by a developing unit 4 to form a toner image, and the density of the toner image is detected by an optical sensor 10. . The optical sensor 10
As shown in FIG. 2A, it comprises two sensors 10a and 10b installed substantially parallel to the drum axis. The sensor 10a is for detecting a mark 20 formed on the aluminum tube 1a, and the sensor 10b is a toner patch 21 (21a, 21a,
21b) is for detecting the toner image. The optical sensor 10 uses an infrared light emitting diode having a wavelength of 890 nm as a light emitting unit. The light emitting unit irradiates the light to a photoconductor and receives reflected light by a phototransistor. The photoreceptor is substantially transparent for this wavelength, while the toner is opaque. Therefore, the sensor 10a can detect the mark 20 on the aluminum tube below (covered by) the photoconductor, and the sensor 10b can detect the toner patch 21 (21a, 21a) formed on the photoconductor.
b) can be detected.

The usable mark 20 is created by changing the optical reflectivity of the conductive support member surface.
The substance of the mark 20 may be, for example, a portion in which the ratio of irregular reflection to specular reflection is changed by changing the surface roughness, or a portion having a different optical spectral reflectance. If the mark is made with surface roughness, the difference in the specularity of the surface of the conductive support member will be detected, so the optical sensor used must be an optical system that can efficiently detect specular reflection (specular reflection). Preferably, it is provided. When a mark is formed with a difference in optical reflectance, the spectral characteristics required for the mark are such that the spectral reflectance of the conductive support member surface is high in the range where the spectral transmittance of the photoconductive layer is relatively high (high transparency range). It is desirable that the difference from the rate is large. In this case, the sensor may detect irregularly reflected light, but the spectral sensitivity of the optical sensor including the light emitting element, the light receiving element, and the optical path forming member is determined by the spectral reflectance of the conductive support member surface and the mark portion. Higher at different wavelengths. In addition, the size, position, and the degree of difference in optical reflectivity of the portion having a different optical surface property as a mark provided on the base tube are appropriately determined by matching with a detection sensor to be used. is there. That is, when the observation range of the detection sensor is sufficiently small and has high sensitivity, the object can be achieved by making the marking small and inconspicuous.

FIG. 2B shows a case where the mark 20 is formed in an image area on the aluminum tube. A case where the mark 20 may be formed in the image area is a case where a selenium-based photoconductor in which the mark does not appear in the image is used. When an OPC photoconductor is used as the photoconductor, a mark 20 is formed in a non-image portion as shown in FIG. This is because a mark appears on an image in the OPC photosensitive member. As shown in FIG. 2B, when the mark 20 is formed on the image portion, toner patch detection and mark detection are performed by the optical sensor 10b, so that the cost is lower than the configuration of FIG. 2A. Becomes

The output of the thermistor or optical sensor is amplified by an amplifier 11 (11a, 11b), passed through an A / D converter 12 (12a, 12b), and then input to a cpu 13. The cpu 13 controls (corrects) the process parameters such as the copy lamp voltage via the charger power supply 14 and the developing bias power supply 15 or the copy lamp driving circuit 8 so that the optimal process control can be performed in accordance with the input information. I do.

That is, when the power is turned on, the photosensitive member 1
Starts rotating, and first, the sensor 10 a detects the mark 20. As a result, a signal synchronized with the rotation of the photoconductor can be obtained. Based on this signal, a toner patch of several cm × several cm is created on the surface of the photoconductor. A standard white plate 9 and a blank lamp 19 are used to create a toner patch. That is, a toner image is created by the reflected light of the standard white plate 9, and the toner image is turned into a patch under the control of the blank lamp 19. For the density of the toner patch, for example, a process parameter is set so that a density of 1.0 is formed as a reference density. In this case, a plurality of toner patches may be created as shown in FIG. 2 (21a, 21b), and control may be performed so as to change the density of each toner patch. As described later, this makes it possible to more accurately control the process parameters.

As described above, the toner patch 21 is created, and the density of the toner patch 21 and the density of the non-image area around the patch are detected by the optical sensor 10b. Then, the ratio of these densities is determined, and the process parameters are corrected based on the result. By changing the screen grid voltage or the like of the charging device, the toner patches 21 having different densities are changed.
When a plurality of are formed, the ratio of the detected density of each toner patch adjacent non-image portion to the detected density of each toner patch is determined, and the process parameter is corrected based on these values. When there are a plurality of toner patches, it is possible to see the change with respect to the density set for each toner patch, so that the process parameter correction direction (for example, whether the density should be controlled to increase or the density decreases) Correction direction, such as whether to control). Therefore, it is necessary to use the toner patch 2
The larger the number of 1, the better.

Next, the structure of the photosensitive member 1 will be described.

As described above, the photosensitive member 1 used in this embodiment uses an aluminum tube as the conductive support member. The conductive support member may be any material as long as the support member itself has conductivity.In addition to aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, chromium, titanium, nickel, vanadium, molybdenum, indium, gold, Platinum or the like can be used. In addition, aluminum, aluminum alloy, indium oxide,
A plastic (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, or polyfluoroethylene) having a layer in which tin oxide or an indium oxide-tin oxide alloy is formed by a vacuum evaporation method can be used.

As a material for the photosensitive layer (photoconductive layer) provided on the conductive support member, selenium, a selenium-based alloy, amorphous silicon, an organic semiconductor photoconductive material, or the like can be used. In particular, the case where an organic photoconductive material is used will be described in detail. An undercoat layer is provided for improving the adhesion of the photoreceptor layer to the conductive support member, improving the coating property, covering defects on the support and improving the charge injection property from the support to the charge generation layer. There is. As materials for the undercoat layer, resins such as polyamide copolymerized nylon, casein, polyvinyl alcohol, cellulose, and gelatin are known. These are dissolved in various organic solvents, and the film thickness is 0.1 to 5
It is applied on a conductive support so as to have a thickness of about μm.

The charge generation layer contains, as a main component, a charge generation material that generates charges by light irradiation, and if necessary, a known binder.
It contains a plasticizer and a sensitizer, and is applied on a conductive support member or an undercoat layer so that the film thickness becomes 1.0 μm or less (dry film thickness). Examples of the charge generation material include a perylene pigment, a polycyclic quinone pigment, a phthalocyanine pigment, a metal phthalocyanine pigment, a squarium dye, an azulhenium dye, a thiapyrylium dye, and a carbazole skeleton, a styrylstilbene skeleton, a triphenylamine skeleton, and a dibenzoophene skeleton. And an azo pigment having an oxadiazole skeleton, a fluorenone skeleton, a bisstilbene skeleton, a distyryloxadiazole skeleton or a distyrylcarbazole skeleton.

The charge transporting layer contains a charge transporting material capable of receiving and transporting charges generated by the charge generating material, a silicon-based leveling material and a binder as essential components, and if necessary, a known plasticizer. Contains sensitizers, etc.
It is applied on the charge generation layer so as to have a dry film thickness of 5 to 70 μm. Examples of charge transport materials include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole Derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4
Electron-donating substances such as -dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, hydrazone derivatives, or fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives,
Examples include an indenopyridine derivative, a thioxanthone derivative, a benzo [c] cinnoline derivative, a phenazine oxide derivative, an electron accepting substance such as tetracyanoethylene, tetracyanoquinodimethane, promanyl, chloranyl, and benzoquinone. The binder constituting the charge transport layer may be any material that is compatible with the charge transport material, such as polycarbonate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane, polyvinyl ketone, polystyrene, and polyacrylamide. Phenolic resin and phenoxy resin.

Example of Preparation of Photoreceptor 1 (1) The surface of a 100 mm-diameter mirror-polished aluminum tube with a width of 2 mm and a length of 30 mm was roughened with # 2000 sandpaper, and the surface roughness was measured with a surface roughness meter. As a result of the measurement, a result of Rmax = 0.1 μ was obtained in the mirror-ground portion, and a result of Rmax = 0.3 was obtained in the rough portion. The raw tube was subjected to ultrasonic and warm bath cleaning treatment for 30 seconds using 1,1,1-trichloroethane at 60 ° C. as an organic solvent. 1 at 20 ° C
After cooling in 1,1-trichloroethane for 30 seconds,
Steam cleaning was performed for 30 seconds using 1,1-trichloroethane, and the solution was allowed to cool in a clean room for 20 minutes. The obtained raw tube was dip-coated by a known dip coating method on the surface of the raw tube so as to have a dried film thickness of 0.5 μm,
After drying at a temperature of 1 ° C. for 1 hour, the following solution B was dip-coated on the surface of the tube coated with the solution A so as to have a dried film thickness of 20 μm, and dried at a temperature of 75 ° C. for 1 hour.

<< Liquid A >> 2 parts by weight of dibromoanthanethrone, 2 parts by weight of a butyral resin (manufactured by Eslec BM-2 Sekisui Chemical Co., Ltd.) and 230 parts by weight of cyclohexanone were subjected to dispersion treatment in a ball mill for 8 hours. liquid.

<< Liquid B >> Hydrazone-based charge transport material [AB
PH, manufactured by Nippon Kayaku Co., Ltd.] 1 part by weight, polycarbonate resin [Panlite L-1250, manufactured by Teijin Chemicals Ltd.] 1
A liquid obtained by dissolving parts by weight in 8 parts by weight of dichloroethane.

FIG. 5 shows the results obtained by measuring the spectral reflectance of the electrophotographic photosensitive member obtained as described above using a spectrophotometer manufactured by Fatal Co., Ltd. As can be seen from this figure, the spectral reflectance is about 80% at 650 nm or more, but is about 25% at the mark portion. Next, this photoconductor was mounted on the copying machine shown in FIG. 1 and a mark was detected. As a result, a pulse signal could be created with a sufficient SN ratio, and one pulse was generated for each rotation of the photoconductor. A signal based on the mark could be created. Further, when this mark was used to actually copy in the above-described copying process, a copied image sufficiently usable for practical use was obtained without image unevenness due to the mark. In addition, the size, position, and the degree of difference in optical reflectivity of the portion having a different surface property, which is a mark provided on the base tube, are not limited to the present embodiment. Are appropriately determined by matching. That is, when the observation range of the detection sensor is sufficiently small and has high sensitivity, the object can be achieved by forming a rough surface having a small width and being inconspicuous.

(2) A mirror-ground aluminum tube having a diameter of 100 mm was used as an organic solvent at 1,1,1-
Ultrasonic and warm bath cleaning treatments were performed for 30 seconds using trichloroethane. Further, after a cold bath in 1,1,1-trichloroethane at 20 ° C. for 30 seconds, steam cleaning was performed for 30 seconds using 1,1,1-trichloroethane, followed by 2 hours in a clean room.
It was left to cool for 0 minutes. Mask the entire surface of the base tube with Teflon tape and a part of the masking is 5 mm wide and 3 mm long.
0 mm, removed from this in a 6 wt% aqueous solution of phosphoric acid (solution temperature 23 ° C.) by applying an AC effective voltage of 20 V for 10 minutes to form an anodized film, and then 30 g / l NiSO
₄ · 6H ₂ O and 15V AC effective voltage in a mixed solution (liquid temperature 23 ° C.) with 30g / l H ₂ BO ₃ was applied to electrolytic coloring 2 minutes. Thereafter, the masking tape was removed, washed again by the same method as described above, and formed a photoconductive layer by the same method as in Example (1). The spectral reflectance of the mark portion from 600 nm to 900 nm by this method was approximately 20% or less. In this method, the optical surface reflectivity could be changed by the effects of both the change in the specular reflectance and the change in the spectral reflectance due to electrolytic coloring. Next, this photoreceptor was mounted on the copying machine shown in FIG. 1 and a mark was detected. As a result, a pulse signal could be created with a sufficient SN ratio.
By generating one pulse for each rotation of the photoreceptor, the signal from the mark could be created. Further, when the actual copying was performed, a copied image sufficiently usable for practical use was obtained without image unevenness due to marks.

(3) Mirror-polished aluminum tube with a diameter of 100 mm was used as an organic solvent at 1,1,1-
Ultrasonic and warm bath cleaning treatments were performed for 30 seconds using trichloroethane. Further, after a cold bath in 1,1,1-trichloroethane at 20 ° C. for 30 seconds, steam cleaning was performed for 30 seconds using 1,1,1-trichloroethane, followed by 2 hours in a clean room.
It was left to cool for 0 minutes. Mask the entire surface of the base tube with Teflon tape and a part of the masking is 5 mm wide and 3 mm long.
After removing in a range of 0 mm and depositing indium oxide by a known vacuum deposition method, the substrate was taken out of the vacuum chamber, the tape was removed, and the tube was washed again in the same manner as described above. Amorphous silicon was deposited on the tube thus obtained by a capacitively coupled high-frequency glow discharge method. The high-frequency power 700
w, a frequency of 13.56 MHz, a raw tube temperature of 250 ° C., and a gas pressure of 6.5 Pa, first, a silane gas flow rate of 100 sccm and a hydrogen gas flow rate of 100 s as an undercoat layer.
ccm, flow rate of diborane gas diluted with hydrogen (50 ppm) 2
Film formation was performed for 30 minutes under a mixed gas condition of 00 sccm and a NO gas flow rate of 50 sccm.
sccm, and 4 under mixed gas conditions with NO gas removed.
The film was formed for a long time to obtain a photoconductive layer. Finally, a film was formed for 15 minutes under a mixed gas condition of a silane gas flow rate of 20 sccm, a hydrogen gas flow rate of 100 sccm, and a methane gas flow rate of 50 sccm to form an overcoat layer. The thus formed electrophotographic photosensitive member was taken out of the vacuum chamber after cooling, and the spectral reflectance was measured. The result shown in FIG. 6 was obtained.
Next, this photoconductor was mounted on the copying machine shown in FIG. 1 and a mark was detected. As a result, a pulse signal could be created with a sufficient SN ratio, and one pulse was generated for each rotation of the photoconductor. A signal based on the mark could be created. Further, when the actual copying was performed, a copied image sufficiently usable for practical use was obtained without image unevenness due to marks.

As described above, any of the above photoconductors can generate a pulse signal with a sufficient SN ratio. By generating one pulse for each rotation of the photoconductor, a signal based on the mark can be generated. I was able to do it.

FIG. 7 shows the result of examining the detection accuracy by repeating formation of a toner patch and density detection 20 times using the above-described photosensitive member. For reference, the results of both the case where the toner patch is created and detected based on the mark signal and the case where it is not used, that is, the case where the toner patch is created and detected asynchronously with the rotation of the photoconductor are shown. Was.

Incidentally, as a method for preparing a toner patch, 30
The blank lamp 19 (FIG. 1) is selectively turned on with a timing so as to form a patch having a size of 36 mm × 36 mm, and the bias voltage applied to the screen grid of the charging charger is set to three types of 300 v, 400 v, and 500 v. Three toner patches were created with variations. At this time, the copy lamp is turned off and the developing bias voltage is set to 20.
The constant value was 0 V. As can be seen from this figure, the variation in the detection result when the toner patches are generated asynchronously exists in the order of ± 0.1 to 0.15 at each toner patch density, whereas according to the embodiment, the detection results vary. The variation of the result is within about ± 0.05, which is satisfactory as the detection accuracy for the process control targeted by the present invention.

FIG. 8 shows another embodiment of the present invention. In the photoconductor device of this embodiment, a disk 31 with a slit is attached to the rotating shaft 30 of the photoconductor 1, and the slit 31a is detected by an optical sensor 32. The slit 31a corresponds to the mark of the present invention.

FIG. 9 shows still another embodiment of the present invention. In this embodiment, a black mark 33 having a width of 3 mm and a length of 15 mm is formed on the end of the surface of the photoconductor 1 by printing. This mark corresponds to the mark of the present invention. As described above, when forming the mark 33 on the photoconductor surface,
It is necessary to provide the mark in a non-image area such as the end of the photoconductor so that the mark is not visualized. The optical sensor is arranged at a position facing this mark. When forming a mark on the surface of the photoconductor, it is conceivable that the properties of the mark itself may change with the use of the photoconductor. In this embodiment, the mark forming position is selected in a non-image area on the surface of the photoconductor and in a range where the cleaning blade does not exist. By doing so, the mark was not subjected to mechanical stress due to the cleaner blade, and could be used without problems for a long period (about 300 k copies).

FIG. 10 shows still another embodiment of the present invention. In this embodiment, the marks formed on the tube are at both ends. For this reason, even if the photoconductor is mounted in the wrong orientation when mounted, there is no problem in detecting the mark.

As described above, the present invention provides high-accuracy process information detecting means when performing a copying process.
Thus, control based on a correct detection result is performed, and a stable copy image quality is supplied. Therefore, if a mark cannot be detected and a synchronizing signal for rotation of the photosensitive member cannot be obtained, such stable copy image quality cannot be provided. Therefore, a warning may be issued to an operation panel or the like when the mark detection cannot be performed when the mark detection is performed after the rotation of the photosensitive member is started, so as to notify the user of the abnormality. FIG. 11 shows a control flow when the warning function is provided. When the mark detection is normally performed, the density of the toner patch is detected and the density of the non-image area is detected and the ratio is obtained after the toner patch is formed, and the process parameter is corrected based on the ratio. When the mark detection cannot be performed normally, a warning is issued. If the state continues even after a predetermined time has elapsed, the copying operation is prohibited. Further, the abnormal information may be loaded into a remote information collection system connected to the host computer via a telephone line. In addition, the operation of the process control is prohibited, that is, the process information is detected by creating a toner patch. Alternatively, the correction of the electrophotographic process parameters may not be performed. This allows
It is possible to prevent erroneous mounting of the photoconductor, and to eliminate mounting of a photoconductor having a defective mark or a different photoconductor, thereby ensuring predetermined performance. Also,
An electrophotographic process parameter for lowering the copy image density may be set. By doing so, it is possible to give a warning to the user and to prompt an early service while preventing a toner scattering accident and an increase in toner consumption into the machine. In order to reduce the image density, for example, a method of lowering the charging conditions (grid voltage value, discharge current value) or increasing the developing bias voltage can be adopted.

In the above-described embodiment, the process information is detected when the power is turned on in the process of forming the toner patch. However, the process information may be detected when the photoconductor is rotated before the copying process is performed. You may go.

The above-described embodiment is an example in which a toner patch is formed and its density is detected, and the electrophotographic process parameters are corrected based on the density. An image may be formed, the surface potential of the electrostatic latent image may be detected, and electrophotographic process parameters may be corrected based on the detected image.

When detecting the surface potential of the electrostatic latent image, a surface potential sensor 50 (see FIG. 1) for detecting the surface potential of the photosensitive member surface is disposed between the blank lamp 19 and the static elimination lamp. For example, it is arranged near the optical sensor 10. When detecting the electrostatic latent image and the surface potential of the area other than the electrostatic latent image and correcting the electrophotographic process parameters based on the ratio, the optical sensor 10
0 (or 33 or 40), an electrostatic latent image is created based on a synchronization signal obtained by the optical sensor 10 detecting the mark 20 (33, 40), and the electrostatic latent image is created. Surface potential sensor 5
Detected by 0.

The surface potential sensor 50 detects the potential on the surface of the photoreceptor, and outputs the signal via an amplifier and an A / D converter.
Input to pu13. Here, FIG. 12 shows a measurement result of how the surface potential detected by the surface potential sensor 50 changes when the distance between the surface potential sensor 50 and the photoconductor changes (when the photoconductor shakes). Is shown. As in the case of detecting the toner concentration by the optical sensor 10, when the distance between the surface potential sensor 50 and the photoconductor changes, the sensor output changes. Therefore, in the same manner as in the above-described embodiment when the density of the toner patch is detected based on the mark detection (synchronization signal), an electrostatic latent image is formed based on the mark detection (synchronization signal), and the surface potential of the electrostatic latent image is reduced. To detect. FIG. 13 shows the result of repeating the creation of the electrostatic latent image and the density detection 20 times. For reference, the results of both the case where the creation and detection of the electrostatic latent image are performed based on the synchronization signal and the case where the creation and detection are performed asynchronously without using the synchronization signal are shown. The electrostatic latent image was prepared under the same conditions as before the toner attachment in the toner patch detection experiment. That is, the bias voltage applied to the screen grid was changed to three types of 300 v, 400 v, and 500 v, and an electrostatic latent image having a size of 30 mm × 36 mm was formed by a blank lamp. Then, the copy lamp was turned off, and the developing processing by the developing tank 4 was not performed. In the case where an electrostatic latent image is formed based on the photoconductor rotation synchronization signal, an electrostatic latent image having a screen grid voltage of 300 V is created 0.5 seconds after the detection of the synchronization signal, and thereafter, an electrostatic latent image of 400 V is generated at 0.1 second intervals. , 500v. FIG. 14 is a time chart thereof. As can be seen from FIG.
When an electrostatic latent image is formed asynchronously, the variation in the detection result is about ± 35 to 40 V in each electrostatic latent image, whereas the variation in the detection result is ± 5 V according to the method of this embodiment. It is in the degree. Therefore, the intended detection accuracy for process control is satisfactory.

When the process control is performed by detecting the surface potential of the electrostatic latent image, similarly to the above-described toner patch detection, if no synchronization signal is detected, a warning is displayed, the process control is invalidated, Processing such as prohibition of copying is performed.

As described above, when the process control is performed without the synchronizing signal, the accuracy of the control is degraded, and a defect occurs in the copy image. But,
If the copying operation is stopped just because a defect occurs in the copy image, a complaint is issued by the user, and the reliability of the copying machine is expected to decrease. In order to solve the above-mentioned problem, when a synchronization signal based on the above-mentioned mark is not obtained from the photoconductor, the condition of each process is set to a predetermined set value (for example, at the time when the copier is assembled and adjustment of each unit is completed). Value) to minimize damage. In addition, quick maintenance can be performed by providing information from the copier body to the store or service store that the synchronization signal cannot be detected.

FIG. 15 shows an example of the configuration of the communication function between the copying machine and the store as means for this purpose.

A signal identifiable by the copying machine is transmitted to the HOST computer via a modem. The HOST computer can collect and process the information of the copying machine itself. The HOST computer can also communicate with a store or a service store. Therefore, the store or the service store can easily know the information of the copying machine body. In particular, a service call or the like can be promptly performed by informing a store or the like of a state in which a mark such as a synchronization signal cannot be detected.

In the above embodiment, an example is shown in which a mark provided on an aluminum tube of a photoreceptor or a slit of a disk provided on a rotating shaft of the photoreceptor is detected by an optical sensor to output a synchronization signal. In addition to such optical property marks, electrical property marks and magnetic property marks are provided,
The detection may be performed by a sensor capable of detecting those marks, and a synchronization signal may be output.

[0054]

According to the present invention, a mirror-ground conductive support is provided.
Rough the surface so that the reflectance is small relative to the body surface
A mark for obtaining a synchronization signal indicating the rotation position of the photoconductor
Formed, and a photoconductive layer is formed from the upper surface thereof.
The mark is protected and will not change during the life of the photoreceptor
I will not do it. Moreover, the mark is provided below the photoconductive layer.
The optical SN between the conductive support and the mark
The mark is always stable because of the sufficient ratio
In this state, it can be detected reliably. Especially OP as photoconductor
When using the C photosensitive body or the like, mark by forming a mark on the non-image area appears is eliminated as an image. If the photoconductor is a selenium-based photoconductor, the mark
Even if is formed in the image area, the image is not affected, and the mark is detected.
The sensor can also be used to detect the density of toner patches.
You. In response to the mark detection, a toner patch is
(Or an electrostatic latent image), the toner patch
(Or electrostatic latent image) is always formed at the same position on the photoreceptor surface.
The process control is accurate. Also, since the mark is not detected when the type of the mounted photoreceptor is different, a warning is issued in this case, or an electrophotographic process parameter for reducing the density of the copy image is set. By prohibiting the process control or the image forming operation, it is possible to prevent the mounting of different types of photoconductors beforehand, and to always ensure the performance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrophotographic apparatus using a photoconductor according to the present invention.

FIGS. 2A and 2B are diagrams showing a configuration of a photosensitive member according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a change in a density detection value due to a shake of a photoconductor;

FIG. 4 is a diagram showing a change in a potential deviation amount due to a shake of a photoconductor;

FIG. 5 shows the spectral reflection characteristics of the photoreceptor of the embodiment.

FIG. 6 shows a spectral reflection characteristic of the photoconductor of the embodiment.

FIG. 7 is a diagram showing a result of toner patch density detection by electrophotography according to the embodiment of the present invention.

FIG. 8

FIG. 10 is a diagram showing another example of mark formation.

FIG. 11 is a flowchart showing control contents at the start of photoconductor rotation.

FIG. 12 is a diagram illustrating a change in a surface potential detection value due to photoconductor shake;

FIG. 13 is a diagram showing a detection result of a surface potential of an electrostatic latent image by electrophotography according to the embodiment of the present invention.

FIG. 14 is a diagram showing a time chart when an electrostatic latent image is formed.

FIG. 15 is a diagram illustrating a configuration example of a communication function between a copier and a store.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 1a Aluminum pipe 1b Photoconductive layer 10 Optical sensor 20 Mark 21 Toner patch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/08 115 G03G 15/08 115 (72) Inventor Motoyuki 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Corporation (72) Inventor Kazuyuki Arai 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A-1-307770 (JP, A) JP-A-4-256982 (JP, A) JP-A-2-293766 (JP, A) JP-A-60-195558 (JP, A) JP-A-59-62880 (JP, A) JP-A-4-15669 (JP, A) JP-A-62-87978 (JP JP, A) JP-A-62-6278 (JP, A) JP-A-3-172865 (JP, A) JP-A-63-45557 (JP, U) JP-A-2-67342 (JP, U) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) G03G 21/00 350-352 G03G 15/00 303 G03G 21/00 370-502 G03G 21/14 G03G 5/00-5/16

Claims (7)

(57) [Claims] An electronic device comprising: an optically detectable mark formed on a surface of a conductive support member; and a photoconductive layer formed thereon.
A photoconductor for photomicrography, wherein the conductive support is mirror-finished.
So that the reflectance of the surface state becomes smaller with respect to the surface of the holding member
Electrophotography characterized by forming the mark by roughening
Photoreceptor. 2. The method according to claim 1, wherein the mark is a selenium-based photoconductor.
In the image area, or in the non-image area if it is an OPC photoconductor.
The electronic photograph according to claim 1, wherein the electronic photograph is formed.
True use photoreceptor. 3. A with a synchronous signal generating means for generating a synchronization signal in response to rotation of the photosensitive member, seeking always determined position on <br/> photosensitive body based on the synchronization signal, determined the constantly La
An electrophotographic process control method, wherein a toner patch is created at a specified position , an image density of the toner patch is detected, and parameters of the electrophotographic process are corrected based on the detected image density. 4. A includes a synchronizing signal generating means in response to rotation of the photosensitive member for generating a synchronization signal, obtains an always-determined areas on the synchronization signal on the basis <br/> photoreceptor decided this always La
Forming an electrostatic latent image in a selected area , detecting a surface potential of the electrostatic latent image, and correcting an electrophotographic process parameter based on the detected surface potential. . 5. A synchronizing signal according to claim 3 or 4.
The generation means uses the electrophotographic photosensitive member according to claim 1.
Detects the mark during rotation of the photoconductor
A means for obtaining a body rotation synchronizing signal.
Child photo process control method. 6. A synchronizing signal according to claim 3 or 4.
The generating means marks the rotating body that rotates in synchronization with the photoconductor.
Using the electrophotographic photoreceptor with
In addition, by detecting the mark, a synchronization signal of the rotation of the photoconductor is obtained.
Electrophotographic process system characterized by the means to obtain
Your way. 7. A synchronous signal according to claim 3 or claim 4.
If no signal is detected, a warning is displayed,
Setting of electrophotographic process parameters to reduce
At least one of invalid process control and prohibited copying
One of the processing electrophotographic process control, characterized in row Ukoto the
Method.