JPH08114932A - Production of electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE: To prevent the generation of coating defect by forming a photosensitive layer on a conductive substrate and after that, polishing by irradiating the conductive substrate with laser beam to provide a part different in optical reflection property. CONSTITUTION: An irradiation device for irradiating the surface of a photoreceptor 1 with laser is provided with a laser generator 5, a freely horizontally movable unit 8 incorporating a mirror 6 and an image formation lens 7, a working bed 10 for supporting the photoreceptor 1 with a rotary driven fixture 9 and a control unit 11 for drive controlling the unit 8 and the fixture 9. And in this case, a marking area 4 is formed by irradiating with the laser beam from above the photosensitive layer 3 to polish after forming the photosensitive layer 3 on the substrate 2 by coating. That is, the marking area is controlled to be different in optical reflection property from the other part. As a result, the cleaning irregularity in a cleaning process and the coating defect in a coating process, which are conventionally generated by forming the photosensitive layer after forming the marking area on the substrate 2, is dissolved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an electrophotographic photosensitive member having a portion having different optical reflection characteristics on the surface of a substrate for controlling an image forming process of an electrophotographic apparatus.

[0002]

2. Description of the Related Art Generally, in an image forming process in an electrophotographic apparatus such as a copying machine, a copying (image forming) start key is input as a starting point, and a photosensitive member is driven and a photosensitive member is transferred to the photosensitive member according to a sequence set in advance by a program. Each process from charge application, latent image formation by exposure, development, paper feeding, image transfer to paper, image fixing on paper, cleaning of the photoconductor surface, and removal of residual potential of the photoconductor is performed, resulting in a copy image. can get.

In recent years, in order to obtain high-quality black solid and halftone images of a constant density in accordance with the market demand for higher image quality of copy images, the charging potential of the photoconductor, the lamp voltage of the optical system, or the toner density is set. Image forming process factors are controlled. For that purpose, the charging potential and the surface potential after exposure are measured with a surface electrometer and the difference from the reference potential is obtained to control the voltage applied to the charger or the lamp voltage of the light source, or a patch with a fixed density. The toner image is formed on a part of the photoconductor, the density of the toner image is measured by an optical sensor, and the ratio of toner in the developer is controlled.

In these methods, an electrostatic latent image or a toner image is formed on a part of the surface of the photoconductor, the surface potential or the toner image density of the formed part is measured, and a good image is obtained based on the information. The control information output from the control circuit as described above is used to control each part of the process, and is usually executed before copying the original document. Among them, the electrostatic latent image or the toner image is formed, for example, by using a signal of a copy start key input as a base point, and after a set time elapses, a patch having a constant density provided on a part of the original plate of the copying machine is exposed. Or after exposure, developing with toner is performed.

In this case, the rotation start position of the photosensitive member when the signal of the copy start key is input is not constant. Therefore, the exposure image or toner image of the patch formed on the surface of the photoconductor is not always formed at a fixed position.
As a result, it is obtained from the electrostatic latent image formed on the surface of the photoconductor due to mechanical variations such as the shape accuracy (roundness) and rotational runout accuracy of the photoconductor, or the variation in photosensitivity due to the position on the surface of the photoconductor. The measurement sensor output of the surface potential or the toner image density obtained from the toner image varies depending on the forming position. Therefore, the measured output value of the post-exposure surface potential or the post-exposure toner image density for a patch having a constant density varies for each copy operation. That is, the image density is not constant for each copy operation, and it is difficult to control to obtain a good image.

Therefore, in recent years, the measurement of the surface potential after exposure or the toner image density after exposure for a patch having a constant density, which is performed for each copy operation, is always performed on the photoconductor so that the measurement is performed at the same position. A portion (marking portion) serving as a signal source indicating the reference position is provided. This marking portion is formed so as to have a different optical reflection characteristic from other areas. For example, JP-A-6-35
Japanese Unexamined Patent Publication No. 6-149136 discloses a method of grinding and forming a marking portion by using a grindstone or tape for grinding, an abrasive, or the like, and Japanese Laid-Open Patent Publication No. 6-149136.

By the way, the photoconductor is formed by laminating a photoconductive layer on a conductive substrate (element tube) made of aluminum or the like. And in any of the above publications,
The marking process is performed on the tube of the photoconductor, and the photosensitive layer is laminated after the marking portion is formed.

[0008]

Forming the photosensitive layer after forming the marking portion at the stage of the raw tube causes the following problems in the manufacturing process of the photosensitive member. .

First, in the cleaning step before forming the photosensitive layer,
The cleaning property of the marking portion, which is ground and shows minute irregularities, deteriorates and cleaning unevenness occurs. For example, a cleaning solvent adheres or chips of the aluminum substrate remain. Then, in the next photosensitive layer forming step, the cleaning unevenness appears as stains and the like. In particular, when the photosensitive layer is formed by a coating method, as shown in FIG. 9, the chips 25 of the aluminum substrate 22 that are left uncleaned enter the coating solution 26 and adhere to the surface of the substrate 22. When the eyeballs are formed or when the substrate 22 is dipped, the marking portion 24 blocks the application of the upper surface of the marking portion 24 to generate streaks 27.
When the sheet was pulled up, the marking portion 24 caused sagging 28 on the lower surface portion of the marking portion 24, resulting in defective coating.

[0010]

In order to solve the above-mentioned problems, the method for producing an electrophotographic photosensitive member according to claim 1 of the present invention is directed to the above-mentioned photosensitive member after forming a photosensitive layer on a conductive substrate. It is characterized in that the layer is irradiated with a laser beam to provide a portion having different optical reflection characteristics on the conductive substrate.

The method for producing an electrophotographic photosensitive member according to a second aspect of the present invention is the method for producing an electrophotographic photosensitive member according to the first aspect, characterized in that an organic photosensitive material is used for the photosensitive layer. I am trying.

[0012]

According to the method of claim 1, after the photosensitive layer is formed on the conductive substrate, the conductive substrate is irradiated with a laser beam to be ground to provide portions having different optical reflection characteristics. .
As a result, in the step of cleaning the conductive substrate (element tube) during the manufacturing of the photoconductor, the conductive substrate has not been ground yet and is smooth, so that cleaning unevenness does not occur. In the subsequent photosensitive layer forming step, it is possible to avoid generation of stains and the like. In particular, when the photosensitive layer is formed by a coating method, it is possible to solve the problem of coating defects such as eyeballs, stripes, and sags that have been conventionally generated.

According to the method of claim 2, an organic photosensitive material is used for the photosensitive layer. As a result, in the photosensitive layer using another photosensitive material, the photosensitive layer was scattered by the irradiation of the laser beam, but in this organic photosensitive layer, the photosensitive layer was not scattered by the irradiation of the laser beam, and the coating film It is possible to maintain a good state and surely provide portions having different optical reflection characteristics on the conductive substrate.

[0014]

【Example】

[Embodiment 1] One embodiment of the present invention will be described with reference to FIGS.
The explanation is based on the following.

As shown in FIG. 1, a photoreceptor 1 according to the present embodiment is formed in a drum shape having a diameter of 30 to 242 mm, and is formed on a conductive substrate (hereinafter referred to as a substrate) 2 made of aluminum or the like. The photosensitive layer 3 is laminated. The surface of the substrate 2 is precision machined to have a surface roughness Rmax of 0.2 to 1.0 μm. The photosensitive layer 3 is an organic photosensitive layer formed by the dip coating method described below.

First, as a subbing layer, 6 parts by weight of a copolymerized nylon resin (CM4000, manufactured by Toray Industries, Inc.) is dissolved in 94 parts by weight of methanol, and the substrate 2 which has undergone the washing step is dipped and applied. Then, it was dried to form a film thickness of 1.0 μm.

Next, 2 parts by weight of ε-type copper phthalocyanine (Riophoton EPPC, manufactured by Toyo Ink Co., Ltd.), butyral resin (Eslec) were formed as a charge generation layer on the undercoat layer.
BL-1 (manufactured by Sekisui Chemical Co., Ltd.) (1 part by weight) and tetrahydrofuran (100 parts by weight) were mixed and dispersed in a ball mill for 8 hours to immerse the substrate 2 again, and after coating, dried at 80 ° C. for 30 minutes. To a film thickness of 0.4 μm.

Furthermore, a butadiene-based charge transport material (1,1-bis (p-
Diethylaminophenyl) -4,4-diphenyl-1,3-
Butadiene, 1 part by weight of Takasago Fragrance Co., Ltd., polycarbonate resin (Panlite L-1225, Teijin Chemicals Co., Ltd.) 1
1 part by weight, 0.0001 parts by weight of a silicone-based leveling agent (KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) dissolved in 10 parts by weight of dichloromethane, the substrate 2 is further dipped and applied, and then dried at 80 ° C. for 1 hour. Then, a film thickness of 17 μm was formed.

Then, laser irradiation was performed on the photosensitive layer 3 as described later to form, for example, a rectangular marking region 4 on the substrate 2 so that its optical reflection characteristics were different from those of the other portions. The marking area 4 is formed outside the image forming area. In addition to the square shape,
An elliptical shape, a circular shape, etc. are conceivable.

The formation of the marking area 4 on the substrate 2 by laser irradiation from the photosensitive layer 3 will be described below with reference to FIG.

The following laser irradiation device is used to irradiate the surface of the photoreceptor 1 with laser. This laser irradiation device is rotationally driven by a laser (YAG laser) oscillator (laser marker SL-475F, maximum output 30 W, manufactured by NEC) 5, a horizontally movable unit 8 incorporating a mirror 6 and an imaging lens 7. Jig 9 ・ 9
Processing unit 10 for supporting the photoconductor 1 by means of the unit 8
And a control unit 11 for driving and controlling the jigs 9.

In the above laser irradiation device, a laser beam 12 having a beam diameter of about 80 μm emitted from the laser oscillator 5 (wavelength 1.06 μm, output 2 W, frequency 8 kH)
_Z ), after passing through the mirror 6, is condensed by the imaging lens 7 and reaches the surface of the base 2 of the photoconductor 1 which is chucked and fixed by the jig 9 on the processing table 10, and is marked. I do. At this time, controlled by the control unit 11,
The unit 8 scans in the direction of arrow AB in the drawing (moves in the drum axial direction), and in synchronization with this, the photosensitive member 1 is rotated in the direction of arrow C in the drawing by the jigs 9 and 9 (moves in the drum circumferential direction).
That is, laser irradiation is performed while the unit 8 scans one time and the photoconductor 1 rotates by a predetermined angle. In addition, the beam to be irradiated has a Gaussian distribution in the intensity distribution and partially overlaps for each beam, so that laser irradiation is performed with uniform intensity. By the irradiation of the laser light 12, the photosensitive layer 3 does not scatter, and the coating state is good.

As a result, the marking area 4 as shown in FIG. 3A is formed on the base 2. The marking area 4 has a rectangular shape and the irradiation pitch (P ₁ × P ₂ ) is 2
It is 5 × 80 μm. Also, marking area 4
As shown in FIG. 3 (b), the surface roughness Rmax on the substrate 2 is about 4 to 9 μm as shown in FIG. Marking area) surface roughness Rma on the substrate 2
x is 0.2 to 0.5 μm. As a result, the light reflection characteristics are clearly different between the marking area 4 and the non-marking area. That is, as shown in FIG. 4, when light that is not absorbed by the photosensitive layer 3 (for example, infrared rays having a wavelength of 950 nm) is applied to the photosensitive body 1 from above the photosensitive layer 3, the light that has passed through the photosensitive layer 3 is not marked. However, the marking area 4 is diffusely reflected due to its surface roughness.

The surface roughness Rmax of 4 to 9 μm of the marking area 4 on the substrate 2 is determined from the coating state of the marking area 4 as shown in Table 1. That is, when the coating state of the marking area 4 is good (samples g and k in the table), the surface roughness Rmax is 4.1 μm and 5.3 μm, and when the coating scatters a little (sample d in the table). Since the surface roughness Rmax of the above is 8.9 μm, it is considered appropriate that the surface roughness Rmax be 4 to 9 μm.

Laser irradiation conditions (laser output, irradiation pitch, etc.) are appropriately selected in order to form the marking area 4 with the above-described surface roughness.

[0026]

[Table 1]

The difference in surface roughness between the marking area 4 and the non-marking area on the photosensitive layer 3 is 0.5 μm.
m or less, more specifically 0.1 μm or less is desirable. This is because when the photoconductor 1 is actually mounted on a laser printer to form an image,
Since there is a large difference in surface roughness on the photosensitive layer 3 between the marking area 4 and the non-marking area, at the boundary portion or the marking area 4, for example, in the developing process,
The toner does not adhere evenly and may scatter or fall off,
This is to prevent a cleaning failure from occurring in the cleaning process.

Further, the irradiated laser beam 12 does not react at all with the photosensitive layer 3 which allows visible light to pass through, but reacts only with respect to the substrate 2 made of aluminum which does not pass through light to weaken the binding force of aluminum molecules. Marking is done by dispersing. At this time, as shown in FIG. 5, although the dispersed aluminum is slightly present in the contact portion between the photosensitive layer 3 and the surface of the substrate 2, it is not scattered near the surface of the cured photosensitive layer 3. For this reason, there is no effect on areas other than the marking area 4, and therefore, the image quality is hardly affected.

Here, the process control of image formation in a laser printer equipped with the photoconductor 1 on which the marking area 4 is actually formed will be described with reference to the flowchart of FIG.

First, when the power source of the laser printer is turned on, the rotation of the photoconductor 1 is started (S1), and at the same time, a long wavelength light is output from the light emitting portion of the optical sensor and the reflected light is received by the light receiving portion. (S2). At this time, the voltage of the light receiving portion is output at every minute time, and the waveform shown in FIG. 7 is obtained (S3). That is, the output value of the marking area 4 is
It is about 30% of the non-marking area, and the marking area 4 can be detected reliably and easily. Then, after detecting the marking area 4, the process control is started based on this portion.

In the process control, first, the reference surface potential or the development density is measured in advance (S4). Next, a normal charging process is performed and the surface potential is measured by a surface electrometer, or after the normal charging process, development is performed and the toner image on the photoconductor 1 is optically measured. (S5). Then, the respective reference values and measured values are compared (S6). If the measured surface potential deviates from the predetermined surface potential, a correction value is calculated (S
7) Then, the output of the charger is corrected based on this correction value (S8). Alternatively, when the measured development density is out of the predetermined density, a correction value is calculated (S7), and the charging output and the laser output are corrected based on this correction value (S8). Then, the print operation is executed. In this way, as a result of executing the process control, the obtained image could maintain a constant image quality.

Next, a comparative example performed with respect to this embodiment will be described below.

[Comparative Example 1] In the photosensitive member according to the present comparative example, the marking method and the like in Example 1 except that the photosensitive layer was formed by vapor deposition / sputtering using a cadmium sulfide (CdS) photosensitive material. And all are the same. However, as shown in FIG. 8, when an attempt was made to perform process control using this photoconductor in a laser printer, the marking area could not be detected well by the optical sensor because the SN ratio was too small. It was Moreover, various laser irradiation conditions at the time of forming the marking area were changed, but none of them showed a sufficient signal output value. Further, in the present photoconductor, the surface roughness of the photoconductive layer in the marking area was too large, so that toner loss and cleaning failure occurred in the image forming process.

[Comparative Example 2] In this comparative example, the marking method is the same as that of the above except that the photosensitive material of the photosensitive layer is changed to amorphous silicon (a-Si) and the photosensitive layer forming method is vapor deposition / sputtering method. All were the same as in Example 1, but the photosensitive layer was scattered by the laser light irradiation during the formation of the marking area. Furthermore, when the image forming operation was carried out by mounting the photoconductor on a laser printer, the surface roughness of the photosensitive layer in the marking area was too large.
Toner drop and cleaning failure occurred.

Comparative Example 3 In this comparative example, the photosensitive material of the photosensitive layer 3 is selenium-based (As ₂ Se ₃ ) as compared with the example 1.
In addition, except that the method for forming the photosensitive layer was changed to the vapor deposition / sputtering method, the marking method and the like were all the same, but the same results as in Comparative Example 2 were obtained.

As described above, according to the method of manufacturing the photoconductor 1 of this embodiment, after the photoconductive layer 3 is formed by coating on the substrate 2, the laser beam 12 is irradiated from the photoconductive layer 3 to grind the marking. Region 4 is formed. That is, the marking region 4 is not yet formed on the substrate 2 before the formation of the photosensitive layer. As a result, cleaning unevenness in the cleaning step, which is the preceding step of the photosensitive layer forming step, and the formation of coating of the photosensitive layer, which have occurred conventionally because the marking layer is formed on the substrate 2 and then the photosensitive layer is formed. Inconveniences such as coating failure in the process are eliminated, the non-defective rate in the production of the photoconductor is improved, and the cost can be reduced. An organic photosensitive material is used for the photosensitive layer 3. As a result, in the photosensitive layer using another photosensitive material, the photosensitive layer was scattered by the laser beam 12 irradiated to form the marking area. , The photosensitive layer 3 is not scattered by the irradiation of the laser beam 12, the coating film state can be well maintained, and the marking region 4 can be reliably formed, and the process control of the image formation using this can be accurately performed. Can be done

The marking area 4 is provided in the photosensitive layer 3 portion of the photosensitive member 1 for the following reason. For example, when the marking areas are provided on the uncoated portions of the photosensitive layer at both ends of the photosensitive member 1, the uncoated portions of the photosensitive area are covered with the DSD (Develo) of the developing tank.
pment Sleeve Distance) In many cases, a method is used in which the colors are contacted to keep the development conditions constant.
This is because the base material becomes rough due to contact with the D color and is damaged, so that the signal in the marking area cannot be detected.

Further, as an extension of the marking process, signals or characters can be recorded on the base 2 and used as information. For example, if the manufacturing number, sensitivity, and the like of the photoconductor are recorded, it is possible to trace a trouble or defect and to separate the photoconductor from other photoconductors.

[Embodiment 2] Next, another embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 7. For convenience of explanation, members having the same functions as those of the members shown in the drawings of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the organic photosensitive material of the photosensitive layer 3 formed on the photosensitive member 1 and the laser irradiation conditions are different from those in the first embodiment.

The photosensitive layer 3 comprises a charge generation layer and a charge transport layer. First, 1 part by weight of dibromoanthanthrone, 1 part by weight of butyral resin (Eslec BM-2, manufactured by Sekisui Chemical Co., Ltd.), and 120 parts by weight of cyclohexanone were prepared as a charge generation layer on the substrate 2 which had already been washed. Then, the product dispersed by a ball mill for 12 hours is applied by a dip coating method and then dried at 80 ° C. for 30 minutes to obtain a film thickness of 0.5.
formed to a thickness of μm. Next, as a charge transport layer on the charge generation layer, 1 part by weight of a hydrazone charge transport material (ABPH, manufactured by Nippon Kayaku Co., Ltd.), a polycarbonate resin (Panlite L-1250, manufactured by Teijin Chemicals Ltd.) ) 1 part by weight, silicone leveling agent (KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.0001
3 parts by weight of dichloroethane was added to 8 parts by weight of dichloroethane, and the mixture was heated and dissolved at 45 ° C, completely melted, and naturally cooled. After dip coating, the product was dried at 80 ° C for 1 hour to give a film thickness of 20.
formed to a thickness of μm.

[0042] Then, using the laser irradiation apparatus of FIG. 2, the output from on the photosensitive layer 3 1W, by irradiating a laser beam 12 of frequency 3KH _Z, irradiation pitch on the substrate 2 (P ₁
A marking area 4 having a size of × P ₂ ) of 66 × 80 μm was formed. At this time, the photosensitive layer 3 was not scattered by the irradiation of the laser beam 12, and the coating film state was good.

Then, actually, the photoconductor 1 on which the marking area 4 is formed is mounted on a laser printer, and while the photoconductor 1 is rotated by an optical sensor mounted in the printer, the output on the light receiving side is monitored. As a result, the waveform shown in FIG. 7 was obtained, and the signal output showing the marking area 4 in the photoconductor 1 could be confirmed. That is, it can be seen that the marking areas 4 having different optical reflection characteristics are well formed in the photoconductor 1.

As described above, also in this embodiment, the same effect as that of the first embodiment was obtained.

[0045]

As described above, in the method for producing an electrophotographic photosensitive member according to claim 1 of the present invention, after a photosensitive layer is formed on a conductive substrate, laser light is irradiated from above the photosensitive layer. It is a method of providing portions having different optical reflection characteristics on the conductive substrate.

As a result, the cleaning property in the cleaning step in the production of the photoconductor is improved, and defects such as coating defects in the photoconductive layer forming process are eliminated, so that the yield rate in the production of the photoconductor is improved. However, this has the effect of reducing costs.

The method for producing an electrophotographic photosensitive member according to claim 2 of the present invention is the same as the method for producing an electrophotographic photosensitive member according to claim 1, wherein an organic photosensitive material is used for the photosensitive layer. .

As a result, the photosensitive layer is not scattered by the irradiation of the laser beam, and a good coating state is maintained,
Since the portions having different optical reflection characteristics can be surely provided on the conductive substrate, there is an effect that the process control of image formation can be accurately executed by using the portions having different optical reflection characteristics.

[Brief description of drawings]

FIG. 1 is a perspective view of a photoconductor according to first and second embodiments of the present invention.

FIG. 2 is an explanatory view of forming a marking area on the photoconductor of FIG. 1 by a laser irradiation device.

3A and 3B show marking areas formed on the photoconductor of FIG. 1, where FIG. 3A is a plan view and FIG. 3B is a sectional view.

FIG. 4 is an explanatory diagram showing a light reflection state in a marking area and a non-marking area.

FIG. 5 is a cross-sectional view showing an existing state of molecules of an aluminum substrate dispersed by laser irradiation.

6 is a flowchart of process control using the photoconductor of FIG.

FIG. 7 is a characteristic diagram showing optical characteristics of the photoconductor of FIG.

FIG. 8 is a characteristic diagram showing optical characteristics of the photoconductors according to Comparative Examples 1 and 3.

FIG. 9 is an explanatory diagram showing a method for coating a photosensitive layer on a substrate in the production of a conventional photosensitive member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor (electrophotographic photoconductor) 2 Conductive substrate 3 Photosensitive layer 4 Marking area (portion having different optical reflection characteristics) 12 Laser light

Claims (2)

[Claims] 1. An electrophotographic apparatus, comprising: forming a photosensitive layer on a conductive substrate; and irradiating a laser beam on the photosensitive layer to provide portions having different optical reflection characteristics on the conductive substrate. Manufacturing method of photoconductor. 2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein an organic photosensitive material is used for the photosensitive layer.