JP6365211B2 - Manufacturing method of image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus.

  In general, an electrophotographic image forming apparatus includes a photosensitive drum that carries an image, a charging roller that charges the photosensitive drum, and a developing roller that supplies a developer to the photosensitive drum. In general, the photosensitive drum includes a base having a cylindrical outer peripheral surface and a coating layer formed on the outer peripheral surface of the base and including a charge transport material. Hereinafter, the coating layer of the photosensitive drum is referred to as a first coating layer. It is conceivable that the first coating layer is formed by dipping.

  In the dipping process, the member to be coated having a cylindrical outer peripheral surface is immersed in the liquid agent in a vertical posture in which the first end and the second end are directed downward and upward, respectively. In this case, the thickness of the coating layer formed on the outer peripheral surface of the member to be coated is not uniform in the longitudinal direction of the member to be coated. That is, the thickness of the lower part of the coating layer tends to be larger than the thickness of the upper part when dipping.

  Accordingly, when the first coating layer is formed by dipping, the interval between the outer peripheral surfaces of the photosensitive drum and the charging roller is not uniform in the longitudinal direction, which may deteriorate the image quality.

  In addition, when the first coating layer is formed by dipping, a roller having a second coating layer formed by dipping may be employed as the charging roller (see, for example, Patent Document 1).

  Further, it is conceivable that the photosensitive drum and the charging roller are supported to face each other so that the first coating layer and the second coating layer have opposite thickness distribution trends. (For example, patent document 1). Thereby, the interval between the outer peripheral surfaces of the photosensitive drum and the charging roller is made uniform in the longitudinal direction thereof, and the charging potential of the photosensitive drum is made uniform.

JP 2004-138847 A

  By the way, when the photosensitive drum and the charging roller are arranged so that the distribution tendency of the thicknesses of their coating layers is opposite, the charging potential of the photosensitive drum is made uniform, but the charge of the photosensitive drum is The amount becomes uneven. As a result, the image quality may be deteriorated.

  Further, when the non-contact type developing roller and the photosensitive drum having the first coating layer by dipping are employed, the gap between the outer peripheral surfaces of the photosensitive drum and the developing roller is not uniform in the longitudinal direction thereof. become. Therefore, a so-called development leak is likely to occur in a portion where the gap between the developing roller and the surface of the photosensitive drum is narrower than the others. As a result, the image quality may deteriorate due to the development leak.

  An object of the present invention is to provide an image forming apparatus capable of preventing deterioration of image quality due to non-uniform thickness of a coating layer when the coating layer of a photosensitive drum is formed by dipping.

  An image forming apparatus according to an aspect of the present invention includes a photosensitive drum that carries an image, a charging roller that charges the photosensitive drum, and a developing roller that supplies a developer to the photosensitive drum. The photosensitive drum includes a first base body having a cylindrical first outer peripheral surface and a first coating layer formed on the first outer peripheral surface and including a charge transport material. The first coating layer is a layer formed by dipping in which the first substrate is immersed in the first liquid agent in a vertical posture in which the first end and the second end are directed downward and upward, respectively. The charging roller includes a second base body having a cylindrical second outer peripheral surface and a second coating layer formed on the second outer peripheral surface. The second coating layer is a layer formed by dipping in which the second substrate is immersed in a second liquid agent in a vertical posture in which the first end and the second end are directed downward and upward, respectively. The developing roller is immersed in the third liquid agent with the third base body having a cylindrical third outer peripheral surface and the third base body in a vertical posture in which the first end and the second end face downward and upward, respectively. It is a layer formed on the third outer peripheral surface by dipping. The charging roller is supported to face the photosensitive drum with the first end of the second base and the second end of the first base facing the same direction. The developing roller is supported to face the photosensitive drum with the first end of the third substrate and the second end of the first substrate facing in the same direction.

  According to the present invention, when the coating layer of the photosensitive drum is formed by dipping, it is possible to provide an image forming apparatus capable of preventing the deterioration of the image quality due to the uneven thickness of the coating layer. .

FIG. 1 is a configuration diagram of an image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the photosensitive drum, the charging roller, and the developing roller in the image forming unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of the photosensitive drum in the image forming apparatus according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view of the photosensitive drum, the charging roller, and the developing roller in the image forming unit of the image forming apparatus according to the second embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the following embodiment is an example which actualized this invention, Comprising: It does not have the character which limits the technical scope of this invention.

[First Embodiment]
First, the configuration of the image forming apparatus 10 according to the first embodiment of the present invention will be described with reference to FIG. The image forming apparatus 10 is an electrophotographic image forming apparatus. As shown in FIG. 1, the image forming apparatus 10 includes a sheet supply unit 2, a sheet conveying unit 3, an image forming unit 4, an optical scanning unit 5, a fixing unit 6, and the like in a housing 100.

  The image forming apparatus 10 is, for example, a printer, a copier, a facsimile machine, or a multifunction machine. The multifunction machine has both the printer function and the copier function.

  The sheet supply unit 2 includes a sheet receiving unit 21 and a sheet sending unit 22. The sheet receiving unit 21 is configured to be able to stack a plurality of recording sheets 9. The recording sheet 9 is a sheet-like image forming medium such as paper, coated paper, postcard, envelope, and OHP sheet.

  The sheet delivery unit 22 rotates in contact with the recording sheet 9 to send the recording sheet 9 from the sheet receiving unit 21 toward the conveyance path 30.

  The sheet conveyance unit 3 includes a registration roller 31, a conveyance roller 32, a discharge roller 33, and the like. The registration roller 31 and the conveyance roller 32 convey the recording sheet 9 supplied from the sheet supply unit 2 toward the image forming unit 4. Further, the discharge roller 33 discharges the recording sheet 9 after image formation from the discharge port of the conveyance path 30 onto the discharge tray 101.

  The image forming unit 4 forms an image on the surface of the recording sheet 9 that is supplied from the sheet sending unit 22 and is moving along the conveyance path 30. The image forming unit 4 includes a photosensitive drum 41 that carries a toner image, a charging unit 42, a developing unit 43, a transfer unit 45, a cleaning unit 47, and the like. The photosensitive drum 41 is an example of an image carrier.

  The photosensitive drum 41 rotates, and the charging unit 42 charges the surface of the photosensitive drum 41 uniformly. Further, the electrostatic latent image is written on the surface of the photosensitive drum 41 charged by the optical scanning unit 5 scanning the laser beam, and the developing unit 43 supplies the developer to the photosensitive drum 41, whereby the electrostatic latent image is written. Develop.

  The charging unit 42 includes a charging roller 420 that charges a portion of the photosensitive drum 41 before the electrostatic latent image is written. The developing unit 43 includes a developing roller 430 that supplies developer toner to a portion of the photosensitive drum 41 where the electrostatic latent image is written. The charging roller 420 and the developing roller 430 are rotatably supported in a state of facing the photosensitive drum 41 from different directions.

  The transfer unit 45 transfers the toner image on the surface of the photosensitive drum 41 to the recording sheet 9 moving on the conveyance path 30. Further, the cleaning unit 47 removes the toner remaining on the surface of the photosensitive drum 41.

  The fixing unit 6 is a device that fixes the image by heating on the recording sheet 9 on which an image, that is, a toner image is formed. The fixing unit 6 includes a heating roller 61 and a pressure roller 62.

  The heating roller 61 includes a heater 611 and rotates in contact with the recording sheet 9 that is moving through the conveyance path 30 in a heated state. The heating roller 61 and the pressure roller 62 send the recording sheet 9 on which an image is formed between them to a subsequent process. As a result, the fixing unit 6 heats the toner on the recording sheet 9 to fix the image on the recording sheet 9.

[Structure of photosensitive drum, charging roller and developing roller]
Next, the structure of the photosensitive drum 41, the charging roller 420, and the developing roller 430 will be described with reference to FIGS.

  The photosensitive drum 41 includes a first base 411 having a cylindrical first outer peripheral surface 411 s and a first coating layer 412 formed on the first outer peripheral surface 411 s. For example, it is conceivable that the photosensitive drum 41 is an organic photoreceptor.

  The first base 411 of the photosensitive drum 41 is, for example, a metal cylindrical member mainly composed of aluminum. The first coating layer 412 of the photosensitive drum 41 is a thin film layer containing at least a charge transport material. The first coating layer 412 in this embodiment is a photosensitive layer containing a charge transport material and a charge generation material. For example, the charge transport material may be a material containing a fluorenone compound, a nitrated compound, a hydrazone compound, an oxadiazole compound, a styryl compound, a carbazole compound or a pyrazoline compound, or other materials.

  It is also conceivable to employ a photosensitive drum 41 in which a first coating layer 412 containing a charge transport material and a photosensitive layer containing a photosensitive material are individually formed. It is also conceivable to employ a photosensitive drum 41 in which a first coating layer 412 containing a charge transport material, a photosensitive layer containing a photosensitive material, and other coating layers are individually formed. In that case, it is considered that layers other than the first coating layer 412 are formed by spray coating.

  The first coating layer 412 is a layer formed by dipping on the first outer peripheral surface 411 s of the first base 411. In the dipping process of the first coating layer 412, the first base 411 is in a vertical posture in which the first end 41 x faces downward and the opposite second end 41 y faces upward. It is immersed in the liquid agent containing the raw material. In addition, the liquid agent containing the raw material of the 1st coating layer 412 is a 1st liquid agent.

  FIG. 3 is a partially omitted cross-sectional view of the photosensitive drum 41 on which the first coating layer 412 is formed by the dipping. In the dipping step, when the first base 411 is immersed in the liquid agent in the vertical posture, the first coating layer 412 has a thickness greater than the thickness of the portion on the second end 41 y side in the longitudinal direction of the photosensitive drum 41. There is a tendency that the thickness of the portion on the one end 41x side becomes larger.

  The distribution tendency of the thickness of the first coating layer 412 as described above appears more prominently in each of the portion 412x near the first end 41x and the portion 412y near the second end 41y in the first substrate 411. Such a distribution tendency of the thickness of the first coating layer 412 is a tendency common to a coating layer formed by dipping on the surface of a member having a cylindrical outer peripheral surface.

  In the photosensitive drum 41, the first coating layer 412 is formed in the remaining intermediate area excluding a part of the first outer peripheral surface 411 s of the first base 411 from both ends. That is, the first coating layer 412 is not formed in a part of the first outer peripheral surface 411 s of the first base 411 near the both ends.

  The charging roller 420 includes a second base 421 having a cylindrical second outer peripheral surface 421 s and a second coating layer 422 formed on the second outer peripheral surface 421 s. Furthermore, the charging roller 420 also has a shaft portion 423 that penetrates the second base 421 along the longitudinal direction thereof. Therefore, the second base 421 is cylindrical. The shaft portion 423 of the charging roller 420 is rotatably supported by a support portion (not shown).

  The second base 421 of the charging roller 420 is an elastic member including a rubber material such as an elastomer. The second coating layer 422 of the charging roller 420 is formed on the second outer peripheral surface 421 s of the second base 421. For example, the second coating layer 422 may be a thin film layer including a material such as hydrin rubber, nitrile rubber, urethane, or nylon, or a thin film layer of other materials. Further, it is conceivable that the second coating layer 422 is an outermost layer formed on the second outer peripheral surface 421s. Thereby, durability of the charging roller 420 and toner releasability are improved.

  In the charging roller 420, the second base 421 is integrated with the shaft portion 423 with the inner surface thereof being in close contact with the shaft portion 423.

  The second coating layer 422 is a layer formed by dipping on the second outer peripheral surface 421 s of the second base 421. In the step of dipping the second coating layer 422, the second base 421 is in a vertical posture in which the first end 42 x faces downward and the opposite second end 42 y faces upward. It is immersed in the liquid agent containing the raw material. In addition, the liquid agent containing the raw material of the 2nd coating layer 422 is a 2nd liquid agent.

  Therefore, like the first coating layer 412, the second coating layer 422 has a tendency that the thickness of the portion on the first end 42x side is larger than the thickness of the portion on the second end 42y side in the longitudinal direction of the charging roller 420. There is.

  By the way, when the photosensitive drum 41 and the charging roller 420 are arranged so that the distribution tendency of the thicknesses of the coating layers is reversed, the charging potential of the photosensitive drum 41 is made uniform, but the charge of the photosensitive drum 41 The amount becomes uneven. As a result, the image quality may be deteriorated.

  When the non-contact type developing roller 430 and the photosensitive drum 41 having the first coating layer 412 by dipping are employed, the gap between the outer peripheral surfaces of the photosensitive drum 41 and the developing roller 430 is not uniform in the longitudinal direction thereof. become. Therefore, a so-called development leak is likely to occur in a portion where the gap between the developing roller 430 and the surface of the photosensitive drum 41 is narrower than the others. As a result, the image quality may deteriorate due to the development leak.

  On the other hand, in the image forming apparatus 10, the photosensitive drum 41, the charging roller 420, and the developing roller 430 have a structure shown below. As a result, when the first coating layer 412 of the photosensitive drum 41 is formed by dipping, it is possible to prevent image quality deterioration due to non-uniform thickness of the first coating layer 412.

  The developing roller 430 includes a third base 431 having a cylindrical third outer peripheral surface 431 s and a third coating layer 432 formed on the third outer peripheral surface 431 s. Furthermore, the developing roller 430 also has a shaft portion 433 that penetrates the third base body 431 along the longitudinal direction thereof. Therefore, the third base 431 is cylindrical. The shaft portion 433 of the developing roller 430 is rotatably supported by a support portion (not shown).

  The third base 431 of the developing roller 430 is a metal cylindrical member mainly composed of aluminum, for example. The third coating layer 432 of the developing roller 430 is formed on the third outer peripheral surface 431s. For example, it is conceivable that the third coating layer 432 is the outermost coating layer formed on the third outer peripheral surface 431s. The third coating layer 432 includes, for example, an alcohol-soluble nylon layer and conductive powder distributed therein. In this case, it is conceivable that the conductive powder is powdered titanium oxide or the like.

  In the developing roller 430, both end portions of the third base 431 are fixed to the shaft portion 433 by fixing members 435.

  Similar to the first coating layer 412, the third coating layer 432 is a layer containing a synthetic resin formed on the third outer peripheral surface 431s of the third base 431 by dipping. In the step of dipping the third coating layer 432, the third base 431 is in a vertical posture in which the first end 43 x faces downward and the opposite second end 43 y faces upward. It is immersed in the liquid agent containing the raw material. In addition, the liquid agent containing the raw material of the 3rd coating layer 432 is a 3rd liquid agent.

  Therefore, like the first coating layer 412 and the second coating layer 422, the third coating layer 432 has a portion closer to the first end 43x than the thickness of the portion closer to the second end 43y in the longitudinal direction of the developing roller 430. The thickness tends to be larger.

  Moreover, when the 3rd base 431 is a metal member which has aluminum as a main component, it is possible that the 3rd outer peripheral surface 431s of the 3rd base 431 is an alumite layer formed by the oxidation process of aluminum. In this case, the third coating layer 432 is formed immediately above the alumite layer. Accordingly, the third coating layer 432 is hardly peeled off from the third base 431 by a so-called anchor effect.

  Here, a specific example of a method for forming the third coating layer 432 of the developing roller 430 will be described. First, a process of forming an oxide film on the surface of the third base 431 before the third coating layer 432 is formed is performed.

  For example, an alumite treatment for forming an alumite layer is performed on the third outer peripheral surface 431 s of the third base body 431 made of metal containing aluminum as a main component. Thereby, the alumite layer having a thickness of, for example, about 10 micrometers is formed on the third outer peripheral surface 431 s of the third base 431.

  Further, a heat treatment process is performed on the alumite layer that is the oxide film of the third base 431. This heat treatment process is a process in which heating at a predetermined constant temperature is continued for a predetermined time. Thereby, a substantially uniform crack can be generated in the entire alumite layer of the third substrate 431. For example, the heat treatment step of the alumite layer may be a step in which heating at a temperature of about 120 ° C. is continued for a time longer than 10 minutes.

  The heat treatment process of the alumite layer is a process for causing cracks in the alumite layer in advance before the dipping process of the third coating layer 432. Thereby, in the drying process of the 3rd coating layer 432 performed later, it can prevent that a new crack arises in the said alumite layer of the 3rd base | substrate 431. FIG.

  Further, the dipping step for forming a conductive resin coating layer on the third outer peripheral surface 431s of the third base 431 on which the alumite layer is formed is performed. For example, in the dipping step, the third base 431 is immersed in a mixed solution containing the binder resin and conductive powder in the vertical posture.

  For example, the binder resin may be alcohol-soluble nylon, and the powder may be powdered titanium oxide. Further, it is conceivable that the dispersion medium of the mixed liquid is 800 [parts by weight] of methanol. In this case, the mixed liquid is obtained by mixing the nylon, the titanium oxide, and the methanol 800 [parts by weight] with, for example, zirconia beads having a diameter of 1.0 millimeter.

  Finally, a drying process of the conductive resin coating layer formed on the third substrate 431 by the dipping is performed. For example, the drying step is a step of drying the conductive resin coating layer for about 10 minutes in an environment of about 130 ° C. Thereby, the 3rd coating layer 432 of thickness about 2-11 micrometers is obtained. It is conceivable that the time for the drying step is shorter than the time for the heat treatment step.

  Since the developing roller 430 has the third coating layer 432 as the outermost layer, durability and toner releasability are improved. Further, if the toner releasability at the developing roller 430 increases, the toner supply efficiency from the developing roller 430 to the photosensitive drum 41 increases. As a result, it is possible to speed up image formation by rotating the photosensitive drum 41 at a higher speed.

  By the way, if a crack occurs in the alumite layer in the drying step, the conductive powder tends to be unevenly distributed in the resin coating layer due to the influence of convection.

  However, as described above, if the crack is previously formed in the alumite layer in the heat treatment step, it is possible to prevent a new crack from being generated in the alumite layer in the drying step. As a result, in the drying step, the conductive powder is uniformly distributed in the resin coating layer, and a uniform third coating layer 432 can be formed.

  The charging roller 420 is supported to face the photosensitive drum 41 with the first end 42x of the second base 421 and the second end 41y of the first base 411 facing in the same direction.

  Similarly, the developing roller 430 is also supported so as to face the photosensitive drum 41 with the first end 43x of the third base 431 and the second end 41y of the first base 411 facing in the same direction.

  Further, the photosensitive drum 41, the charging roller 420, and the developing roller 430 rotate in a state where the rotation center line 41c of the photosensitive drum 41, the rotation center line 42c of the charging roller 420, and the rotation center line 43c of the developing roller 430 are parallel to each other. Supported as possible.

  The charging roller 420 in this embodiment is supported in a state where the outer peripheral surface thereof is in contact with the outer peripheral surface of the photosensitive drum 41. On the other hand, the developing roller 430 in the present embodiment is supported in a non-contact state with a slight gap between the outer peripheral surface and the outer peripheral surface of the photosensitive drum 41.

  For example, disk-shaped spacers 434 attached to the shaft portion 433 of the developing roller 430 are in contact with the outer peripheral surfaces of both ends of the photosensitive drum 41 where the first coating layer 412 is not formed. The spacer 434 keeps the distance between the photosensitive drum 41 and the developing roller 430 constant.

  In the image forming apparatus 10, the photosensitive drum 41 and the charging roller 420 are arranged so that the distribution tendency of the thicknesses of the coating layers is reversed. In this case, the thickness distribution of the first coating layer 412 and the thickness distribution of the second coating layer 422 are offset. Therefore, the positional relationship between the outer peripheral surface of the charging roller 420 and the outer peripheral surface of the photosensitive drum 41 is uniform in the longitudinal direction of the charging roller 420.

  Further, in the portion of the first coating layer 412 on the photosensitive drum 41 on the second end 41y side where the thickness is small, that is, in the portion with a small capacitance, the discharge from the second base 421 of the charging roller 420 to the photosensitive drum 41 occurs. The second coating layer 422 having a large thickness is suppressed. On the other hand, in the portion on the first end 41x side where the thickness is large in the first coating layer 412 of the photosensitive drum 41, that is, the portion where the electrostatic capacity is large, the discharge from the second base 421 of the charging roller 420 to the photosensitive drum 41 occurs. This is facilitated by the small thickness of the second coating layer 422. Therefore, the charging potential of the photosensitive drum 41 is made uniform in the longitudinal direction of the photosensitive drum 41.

  Further, the portion of the photosensitive drum 41 on the second end 41y side where the thickness of the first coating layer 412 is small has a large amount of charge on the surface, so that it becomes darker and more easily developed than usual. However, in the portion on the second end 41 y side of the photosensitive drum 41, the substantial developing bias is reduced due to the presence of the portion on the first end 43 x side having a large thickness in the third coating layer 432 of the developing roller 430. . Such distribution of the developing bias suppresses a tendency that the toner image is formed at a density different from the original density due to the non-uniformity of the thickness of the first coating layer 412.

On the other hand, the portion of the photosensitive drum 41 on the first end 41x side where the first coating layer 412 is thick is in a state where it is thinner and more easily developed than usual. However, in the portion on the first end 41x side of the photosensitive drum 41, the substantial developing bias is increased due to the presence of the portion on the second end 43y side of the third coating layer 432 of the developing roller 430 having a small thickness. . This also suppresses the tendency for the toner image to be formed at a density different from the original density due to the uneven thickness of the first coating layer 412.

  Therefore, when the image forming apparatus 10 is employed, when the first coating layer 412 of the photosensitive drum 41 is formed by dipping, the image quality is deteriorated due to the uneven thickness of the first coating layer 412. Can be prevented.

  In the present embodiment, the clearance between the outer peripheral surfaces of the non-contact type developing roller 430 and the photosensitive drum 41 is uniform in the longitudinal direction. Therefore, development leakage due to the non-uniformity of the thickness of the first coating layer 412 hardly occurs. As a result, it is possible to prevent image quality deterioration due to the development leak.

  Furthermore, in the present embodiment, a wide gap is not easily generated between the non-contact type developing roller 430 and the outer peripheral surface of the photosensitive drum 41. Thereby, it is possible to prevent the developer from scattering from the gap between the developing roller 430 and the photosensitive drum 41.

[Second Embodiment]
Next, an image forming apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the photosensitive drum 41, the charging roller 420, and the developing roller 430 in the image forming apparatus according to the second embodiment. In FIG. 4, the same components as those shown in FIGS. 1 to 3 are given the same reference numerals. Hereinafter, differences from the image forming apparatus 10 in the image forming apparatus according to the second embodiment will be described.

  In the image forming apparatus according to the second embodiment, the structures and orientations of the photosensitive drum 41, the charging roller 420, and the developing roller 430 are the same as those in the image forming apparatus 10.

  The image forming apparatus according to the second embodiment is different from the image forming apparatus 10 in that the developing roller 430 is in contact with the photosensitive drum 41. That is, in this embodiment, a contact type developing roller 430 is employed.

  In general, when the contact-type charging roller 420 is employed, the above-described problem of development leakage hardly occurs. Also in the present embodiment, the same effects as when the image forming apparatus 10 is employed can be obtained.

[Application example]
In each embodiment shown above, it is also conceivable that the charging roller 420 is a non-contact type roller supported in a non-contact state with respect to the photosensitive drum 41.

  Further, in each of the embodiments described above, it is conceivable that a disc-shaped spacer is attached to the shaft portion 423 of the charging roller 420 as with the spacer 434 of the developing roller 430.

  In each embodiment, a non-contact type charging roller 420 may be employed. In this case, the second base 421 of the charging roller 420 may be a hard member. For example, it is conceivable that the second base 421 is a metal cylindrical member mainly composed of aluminum.

  The image forming apparatus according to the present invention can be freely combined with the above-described embodiments and application examples, or can be appropriately modified within the scope of the invention described in each claim. Alternatively, it may be configured by omitting a part.

2: Sheet feeding unit 3: Sheet conveying unit 4: Image forming unit 5: Optical scanning unit 6: Fixing unit 9: Recording sheet 10: Image forming apparatus 21: Sheet receiving unit 22: Sheet sending unit 30: Conveying path 31: Resist Roller 32: Conveying roller 33: Discharge roller 41: Photosensitive drum 41c: Rotation center line 41x of the photosensitive drum: First end 41y of the first base: Second end of the first base 42: Charging unit 42c: Rotation center of the charging roller Line 42x: First end 42y of the second substrate: Second end 43 of the second substrate: Developing unit 43c: Rotation center line 43x of the developing roller: First end 43y of the third substrate: Second end 45 of the third substrate : Transfer unit 47: cleaning unit 61: heating roller 62: pressure roller 100: casing 101: discharge tray 411: first base 411s: first outer peripheral surface 412: first coating layer 4 20: charging roller 421: second substrate 421s: second outer peripheral surface 422: second coating layer 423: charging roller shaft 430: developing roller 431: third substrate 431s: third outer peripheral surface 432: third coating layer 433 : Shaft portion 434 of developing roller: Spacer 435: Fixing member 611: Heater

Claims (3)

It is formed on the first substrate and before Symbol first outer peripheral surface on having a cylindrical first outer peripheral surface having a first coating layer containing a charge transporting material, a photosensitive drum carrying an image,
A second coating layer formed on the second substrate and before SL on the second outer peripheral surface having a cylindrical second outer peripheral surface, a charging roller for charging said photosensitive drum,
A third coating layer formed on the third substrate and before SL on the third outer peripheral face having a cylindrical third outer peripheral surface, a developing roller for supplying the developer to the photosensitive drum, Ru with a An image forming apparatus manufacturing method comprising :
The first base of the first base in the longitudinal direction of the first base is dipped by dipping the first base in the first liquid in a vertical posture with the first end and the second end facing downward and upward, respectively . the thickness of the portion of the end side to form the first coating layer big than the thickness of the second end-side portion of the first substrate,
The first base of the second base in the longitudinal direction of the second base is carried out by dipping the second base in the second liquid agent in a vertical posture with the first end and the second end facing downward and upward, respectively . the thickness of the portion of the end side to form the second coating layer big than the thickness of the second end-side portion of the second substrate,
The first base of the third base in the longitudinal direction of the third base is dipped by dipping the third base in the third liquid in a vertical posture with the first end and the second end facing downward and upward, respectively . the thickness of the portion of the end side forming the third coating layer big than the thickness of the second end-side portion of the third substrate,
The photosensitive drum, the charging roller, and the developing roller are rotatably supported in a state where the rotational center line of the photosensitive drum, the rotational center line of the charging roller, and the rotational center line of the developing roller are parallel to each other. The charging roller is supported in a state in which the first end of the second base and the second end of the first base face the same direction so as to face the photosensitive drum and are not in contact with the photosensitive drum. The developing roller is opposed to the photosensitive drum with the first end of the third substrate and the second end of the first substrate facing in the same direction, and is not in contact with the photosensitive drum. A method of manufacturing an image forming apparatus to be supported. The method for manufacturing an image forming apparatus according to claim 1, wherein the third coating layer includes an alcohol-soluble nylon layer and conductive powder distributed therein. The method for manufacturing an image forming apparatus according to claim 2, wherein the conductive powder is powdered titanium oxide.

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