JPH10133541A - Assembling method of image forming unit and the image forming unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the assembling method of an image forming unit capable of making the interval between a photoreceptor drum and a developing roller a proper fixed interval. SOLUTION: The inserted part 81 of a drum bearing member 44 is inserted into a drum bearing attaching hole 8 formed in a unit side plate 41, to fix the drum bearing member 44 on the unit side plate 41. Then, the unit side plate 41 is placed on a side plate placing plate 92, so that a bearing hole 82 formed in the drum bearing member 44 and a roller bearing attaching hole 89 formed in the unit side plate 41 are put through a reference pin 96 corresponding to the rotary shaft of the photoreceptor drum and a second reference pin 97 corresponding to the rotary shaft of the developing roller, respectively. After that, the bearing hole 86 of a roller bearing member 46 is put through the second reference pin 97, to fix the roller bearing member 46 on the unit side plate 41. Thus, an image forming device is attached/assembled between a pair of unit side plates to which the drum bearing member 44 and the roller bearing member 46 are attached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for assembling an image forming unit in which a drum unit and a developing unit are integrated by a pair of unit side plates. The invention also relates to an image forming unit in which a drum unit and a developing unit are integrated by a pair of unit side plates.

[0002]

2. Description of the Related Art An image forming apparatus is an essential component of an image forming apparatus such as a copying machine, a facsimile machine and a printer. An imaging device typically includes a photoreceptor drum,
A drum unit for forming an electrostatic latent image, and a developing unit for developing the electrostatic latent image into a toner image including a developing roller are included, and both portions are unitized. Often.

[0003]

When the drum unit and the developing unit are combined, it is necessary to maintain an appropriate constant distance between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller. This is because the developing roller is driven to rotate while holding the toner on the peripheral surface thereof, so that the toner on the peripheral surface comes into contact with the surface of the photosensitive drum, thereby supplying the toner to the surface of the photosensitive drum. Therefore, if the distance between the peripheral surface of the developing roller and the peripheral surface of the photosensitive drum is not set properly, the amount of toner supplied to the photosensitive drum becomes unstable, and defects such as density unevenness occur in an image formed on paper. This is because there is a risk of occurrence.

[0004] However, in the apparatus having the above configuration,
When each unit is incorporated in an image forming apparatus, the distance between the photosensitive drum and the developing roller sometimes varies. Therefore, the inventor of the present application considered assembling the drum unit and the developing unit as one image forming unit before assembling the image forming apparatus newly.

The present invention has been made under such a background, and has as its object to provide a method of assembling an image forming unit in which the distance between a photosensitive drum and a developing roller can be set to an appropriate constant distance. I have. It is another object of the present invention to provide an image forming unit in which a distance between a photosensitive drum and a developing roller is set to an appropriate constant distance.

[0006]

According to a method of assembling an image forming unit according to the present invention, the image forming apparatus including a photosensitive drum and a developing roller is provided between a pair of unit side plates. A method of assembling an integrated image forming unit, wherein a bearing mounting hole for mounting a bearing member for receiving a rotating shaft of a photoreceptor drum and a developing roller is formed, and at least one of the bearing mounting holes is a bearing. A first step of preparing a unit side plate capable of adjusting a mounting position of a member, and a first reference pin and a second reference pin respectively corresponding to a rotation axis of a photosensitive drum and a rotation axis of a developing roller are predetermined. A second step of preparing a reference device erected at intervals, and in a state in which at least a bearing member is not mounted in an adjustable bearing mounting hole at a mounting position, A third step of setting the knit side plate on the reference device, and using the first reference pin and the second reference pin, mounting the one of the bearing members fixed to the unit side plate to the adjustable bearing mounting hole. A fourth step of adjusting the position of the other bearing member to be mounted and removing the unit side plate to which each bearing member is attached from a reference device, and a photoconductor between a pair of unit side plates to which each bearing member is attached. Attaching an image forming apparatus including a drum and a developing roller and assembling the image forming apparatus.

According to a second aspect of the present invention, in the image forming unit assembling method according to the first aspect, in the third step, one of the bearing members is attached to the unit side plate, and the attached bearing member is the second one. The unit side plate is set on the reference device so as to match one reference pin, and in the fourth step,
An image forming unit assembling method, wherein the other bearing member is attached in accordance with a second reference pin.

According to a third aspect of the present invention, in the image forming unit assembling method according to the first aspect, in the third step, the unit side plate is attached to the reference plate while no bearing member is mounted in any of the bearing mounting holes. In the fourth step, one of the bearing members is attached to the unit side plate in accordance with the first reference pin, and then the other bearing member is attached to the unit side plate in accordance with the second reference pin. Is an assembling method of the image forming unit.

According to the first aspect of the present invention, the bearing member for receiving the rotating shafts of the photosensitive drum and the developing roller is a reference member in which the first reference pin and the second reference pin are erected at predetermined intervals. It is fixed to the unit side plate using a container. Specifically, as described in claim 2, one bearing member is attached to the unit side plate,
The unit side plate is set on the reference device so that the attached bearing member matches the first reference pin. Thereafter, the other bearing member is attached to the second reference pin.

Further, as described in claim 3,
First, the unit side plate is set on the reference device in a state where the bearing member is not attached to any of the bearing attachment holes.
Then, after one bearing member is attached to the unit side plate in accordance with the first reference pin, the other bearing member is attached to the unit side plate in accordance with the second reference pin. In any of the above methods, the distance between the bearing member for receiving the rotating shaft of the photosensitive drum and the bearing member for receiving the rotating shaft of the developing roller can be made constant.

Therefore, the interval between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller can be set to a proper constant interval, and the interval does not vary. Therefore, the toner supply amount from the developing roller to the photosensitive drum becomes constant,
There is no possibility that a defect such as uneven density occurs in an image formed on the paper. According to a fourth aspect of the present invention, an image forming apparatus including a photosensitive drum and a developing roller is an integrated image forming unit provided between a pair of unit side plates to receive a rotating shaft of the photosensitive drum. Drum bearing member, and a roller bearing member for receiving a rotating shaft of the developing roller, wherein the drum bearing member and the roller bearing member have a predetermined distance between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller. An image forming unit, which is attached to a unit side plate so as to be spaced from each other.

According to the configuration of the fourth aspect, the image forming apparatus including the photosensitive drum and the developing roller is provided and integrated between the pair of unit side plates, and the drum bearing member and the roller bearing member are It is attached to the unit side plate so that the interval between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller is a predetermined interval. Therefore, as in the case where the drum unit and the developing unit are separately unitized,
When each unit is incorporated in the image forming apparatus, there is no problem such as a variation in the interval between the photosensitive drum and the developing roller.

According to a fifth aspect of the present invention, the drum bearing member and the roller bearing member are attached to the unit side plate and assembled by the method according to any one of the first to third aspects. An image forming unit according to claim 4. According to the fifth aspect of the present invention, since the image forming unit is assembled by the assembling method according to any one of the first to third aspects, the distance between the drum bearing member and the roller bearing member is always constant. That is, there is no variation in the interval. Therefore, since the distance between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller is always appropriate, the amount of toner supplied from the developing roller to the photosensitive drum is stable, and the density of the image formed on the paper is not uniform. There is no possibility of causing a problem.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a main configuration of a copying machine provided with an image forming unit according to an embodiment of the present invention. In this embodiment, an image forming unit of a copying machine will be described as an example. However, the present invention can be applied to an image forming unit of an image forming apparatus such as a printer or a facsimile apparatus other than the copying machine.

An original (not shown) is provided on the upper surface of the copying machine main body.
A transparent document placing plate 1 for placing the document is placed. An optical system 2 is provided below the original placing plate 1, and an image forming unit 3 according to an embodiment of the present invention is provided below the optical system 2. The optical system 2 includes the original placing plate 1
It has a light source 21 for illuminating a document placed thereon. The light of the light source 21 is reflected by the document, and the reflected light is reflected by the first mirror 22 toward the second mirror 23. The light from the first mirror 22 is turned back on its optical path by the second mirror 23 and the third mirror 24, and is guided to the lens 25. The light focused by the lens 25 is reflected by the fourth mirror 26 and is
Incident on.

The image forming unit 3 includes a drum unit 60
And a developing unit 61 are included. The drum unit 60 includes a photosensitive drum 32 and a main charger 33.
And a cleaning device 35. During image formation, the photosensitive drum 32 is rotated at a constant speed in the direction of arrow 31. After the surface of the photoconductor drum 32 is uniformly charged by the discharge of the main charger 33, the surface is exposed by light incident from the optical system 2. Then, the charged charge in the exposed portion escapes, and a charged area and a non-charged area corresponding to the inverted image of the document are generated, so that an electrostatic latent image is formed on the surface of the photosensitive drum 32. .
When the photosensitive drum 32 is further rotated, the surface of the photosensitive drum 32 on which the electrostatic latent image has been formed faces the developing unit 61 next.

The developing unit 61 includes a housing 34
A developing roller 36 for supplying the toner to the surface of the photosensitive drum 32; a stirring device 37 for stirring the toner and the carrier in the housing 34; and a stirring device 37 for feeding the toner in a toner hopper (not shown) into the housing 34. A supply spiral 38 is provided. In this embodiment, a two-component developer including a toner and a carrier is used. When the toner and the carrier in the housing 34 are stirred by the stirring device 37, the toner and the carrier are charged by friction, and the surface of the carrier is charged. Adheres to the toner. Then, the carrier to which the toner has adhered adheres to the peripheral surface of the developing roller 36 to form a so-called developer spike. When the ears come into contact with the electrostatic latent image formed on the surface of the photosensitive drum 32, the toner moves to a charged area, and the electrostatic latent image is developed into a toner image.

As described above, in the system in which the toner layer formed on the peripheral surface of the developing roller 36 is brought into contact with the peripheral surface of the photosensitive drum 32 for development, the peripheral surface of the photosensitive drum 32 and the peripheral surface of the developing roller 36 are formed. If the distance d to is not set properly,
The supply amount of toner to the photosensitive drum 32 becomes unstable,
Problems such as uneven density occur in the image formed on the paper. In a conventional apparatus, an image forming apparatus is divided into a drum unit and a developing unit, and when these are incorporated in a copying machine, they are aligned so that a distance between a photosensitive drum and a developing roller is constant. Was. However, in the imaging unit 3 according to the present invention, the drum unit and the developing unit are integrated,
Are pre-positioned so as to be at proper intervals, so that there is no need to perform positioning when assembling into a copying machine.

When the photosensitive drum 32 is further rotated,
The toner image on the surface of the photosensitive drum 32 is
Opposing the transfer charger 4 provided below. On the other hand, at timing synchronized with the timing when the toner image comes to the position facing the transfer charger 4, the registration roller 5 installed near the photosensitive drum 32 is driven to rotate, and the paper P
Is supplied. Then, due to the discharge of the transfer charger 4, the toner on the surface of the photosensitive drum 32 moves to the sheet P and adheres to the sheet P.

The sheet P on which the toner image has been transferred is guided to the fixing device 7 by the transport belt 6. The fixing device 7 includes a pressure roller 71 and a heat roller 72.
The toner image transferred to the sheet P is fixed on the sheet. The sheet P after the fixing process is discharged out of the copying machine main body by a transport mechanism (not shown).

Photosensitive drum 3 after toner image is transferred
Part of the toner remains on the surface of No. 2. After transfer,
When the photosensitive drum 32 is further rotated, the area where the residual toner has adhered faces the cleaning device 35 provided in the image forming unit 3. The cleaning device 35 includes
Cleaning blade 39 and toner recovery spiral 40
And are included. The residual toner adhering to the surface of the photosensitive drum 32 is scraped off by the cleaning blade 39 and collected by a toner collection spiral 40 into a container (not shown) outside the cleaning device 8.

FIG. 2 is a perspective view showing an external configuration of the image forming unit 3. The image forming unit 3 of FIG. 2 shows a state in which the image forming unit 3 is set in the copying machine as viewed from the rear side. Conventionally, the image forming unit is composed of two units, the drum unit 60 and the developing unit 61. However, in the copying machine according to this embodiment, these units are integrated and configured as the image forming unit 3. I have. This unitization is performed by a pair of unit side plates 41 and 42.
This is achieved by supporting the drum unit 60 and the developing unit 61 between them. In this way, the drum unit 60 and the developing unit 61 are integrated to form the image forming unit 3 because the distance d (see FIG. 1) between the photosensitive drum 32 and the developing roller 36 is always set to an appropriate constant interval. Because I want to.

Referring to FIG. 2, unit side plates 41, 42
At a predetermined position, a drum bearing member 44 is accurately positioned and attached according to a method described later, and the rotating shaft 43 of the photosensitive drum 32 is attached to the drum bearing member 4.
4 rotatably supported. Further, a roller bearing member 46 for rotatably supporting the rotating shaft 45 of the developing roller 36 is attached to the unit side plates 41 and 42 at an accurate position by a method described later.

Further, bearing holes 48, 50, 52 are formed at predetermined positions of the unit side plates 41, 42. The bearing holes 48, 50, and 52 are respectively provided with a rotating shaft 47 of the agitator 37 (see FIG. 1), a rotating shaft 49 of the supply spiral 38 (see FIG. 1), and a rotating shaft 51 of the toner recovery spiral 40 (see FIG. 1). , Which are rotatably supported. The housing 34 of the developing unit and the housing of the cleaning device 35 have their longitudinal ends fixed to the unit side plates 41 and 42 with screws (not shown) or the like, and are held in a state of being sandwiched by the unit side plates 41 and 42. ing. Reference numeral 53 denotes the cleaning blade 39 and the photosensitive drum 32 shown in FIG.
This is a thrust gear for thrusting the cleaning blade 39 in the direction of the rotation shaft 43 of the photosensitive drum 32 so as to remove foreign matter such as paper powder sandwiched between the surface and the surface.

In FIG. 2, the drum bearing member 44 and the roller bearing member 46 provided on the unit side plate 42 side.
The illustration of the bearing holes 48, 50, and 52 is omitted. Next, referring to FIG. 3 and FIG.
Will be described. As described above, in order to prevent a problem such as density unevenness from occurring in an image formed on a sheet, the distance d between the photosensitive drum 32 and the developing roller 36 is set.
(See FIG. 1) must always be at regular intervals. For this purpose, the intervals between bearing holes formed in the unit side plates 41 and 42 for receiving the rotation shafts of the photosensitive drum 32 and the developing roller 36 must be constant.
However, it is difficult to accurately form the bearing holes in the unit side plates 41 and 42 due to processing technology. Therefore, in the present invention, a drum bearing member 44 and a roller bearing member 46 for receiving the rotating shafts of the photosensitive drum 32 and the developing roller 36 are provided, and a method of attaching these bearing members to the unit side plates 41 and 42 is devised. doing.

In the following description, only the unit side plate 41 will be described, but the positioning of the drum bearing member 44 and the roller bearing member 46 with respect to the unit side plate 42 is performed in substantially the same manner. First, the unit side plate 41, the drum bearing member 44, and the roller bearing member will be described.

The unit side plate 41 includes a drum bearing member 4
A drum bearing mounting hole 88 into which the fourth insertion portion 81 (described later) is inserted is formed in advance. Drum bearing mounting hole 88
Is formed substantially the same as the diameter of the insertion portion 81. The unit side plate 41 includes a drum bearing member 44.
A screw hole 64 into which the screw 62 is screwed when fixing the screw to the unit side plate 41 is formed.

Further, at a predetermined position of the unit side plate 41, a roller bearing mounting hole 89 through which an insertion portion 85 (described later) of the roller bearing member 46 is inserted is formed in advance.
The roller bearing mounting hole 89 is formed in a long hole so that the mounting position of the roller bearing member 46 with respect to the unit side plate 41 can be adjusted. A screw hole 65 into which a screw 63 for attaching the roller bearing member 46 to the unit side plate 41 is formed is formed in the unit side plate 41.

On the other hand, a bearing hole 82 for rotatably receiving the rotating shaft 43 of the photosensitive drum 32 is formed through the drum bearing member 44. The drum bearing member 44 has a mounting portion 80 for fixing the drum bearing member 44 to the unit side plate 41, and an insertion portion 81 that is inserted into a drum bearing mounting hole 88 formed in the unit side plate 41.
Are provided. A plurality of screw insertion holes 83 are formed in the attachment portion 80, and the screws 62 are inserted into the screw insertion holes 83, and the ends of the screws 62 are attached to the unit side plate 41.
The drum bearing member 44 is fixed to the unit side plate 41 by being screwed into the screw hole 64.

The roller bearing member 46 includes a developing roller 36
A bearing hole 86 for rotatably receiving the rotating shaft 45 is formed. Further, the roller bearing member 46 is provided with a mounting portion 84 for fixing the roller bearing member 46 to the unit side plate 41 and an insertion portion 85 inserted into a roller bearing mounting hole 89 formed in the unit side plate 41. Have been. The attachment portion 84 has a plurality of screw insertion holes 87 formed therein. The screw 63 is inserted into the screw insertion hole 87, and the tip of the screw 63 is screwed into the screw hole 6 of the unit side plate 41.
By being screwed into 5, the roller bearing member 46 is fixed to the unit side plate 41. The screw insertion hole 87 is formed in a long hole elongated in the same direction as the roller bearing mounting hole 89 formed in the unit side plate 41 so that the mounting position of the roller bearing member 46 with respect to the unit side plate 41 can be adjusted.

Next, a reference device 90 used when the drum bearing member 44 and the roller bearing member 46 are attached to the unit side plates 41 and 42 will be described. The reference device 90 is
A base plate 91 and a side plate mounting table 92 arranged on the base plate 91
And a toggle clamp 93 disposed on the right side of the side plate mounting table 92 in FIG.

The side plate mounting table 92 is provided with a first reference pin 96 corresponding to the rotation shaft 43 of the photosensitive drum 32 and a second reference pin 97 corresponding to the rotation shaft 45 of the developing roller 36. The distance D between the first reference pin 96 and the second reference pin 97 is such that the distance d (see FIG. 1) between the peripheral surface of the photosensitive drum 32 and the peripheral surface of the developing roller 36 is an appropriate distance. The distance between the rotating shaft 43 of the drum 32 and the rotating shaft 45 of the developing roller 36 is equal. Therefore, by attaching the drum bearing member 44 and the roller bearing member 46 to the unit side plates 41 and 42 in accordance with the first reference pin 96 and the second reference pin 97, respectively, the interval between the drum bearing member 44 and the roller bearing member 46 is reduced. Can be constant.

When positioning the drum bearing member 44 and the roller bearing member 46 with respect to the unit side plate 41, an operator inserts the insertion portion 81 of the drum bearing member 44 into a drum bearing mounting hole 88 formed in the unit side plate 41. The screw 62 is screwed into the screw hole 64 through the screw through hole 83. As a result, the drum bearing member 44 is mounted and fixed at a predetermined position on the unit side plate 41.

Next, a bearing hole 82 formed in the drum bearing member 44 and a roller bearing mounting hole 89 formed in the unit side plate 41 are respectively provided with a first reference pin 96 and a second reference pin 96.
The unit side plate 41 to which the drum bearing member 44 is attached is mounted on the side plate mounting table 92 so as to be inserted into the reference pin 97. After placing the unit side plate 41, the bearing hole 86 of the roller bearing member 46 is inserted through the second reference pin 97. At this time, the leading end portions of the insertion portion 81 of the drum bearing member 44 and the insertion portion 85 of the roller bearing member 4 inserted into the drum bearing mounting hole 88 and the roller bearing mounting hole 89, respectively, are formed on the side plate mounting table 92. The unit side plate 41 is fitted in the first concave portion 94 and the second concave portion 95.
Does not rise with respect to the side plate mounting table 92.

In this state, by operating the operation lever of the toggle clamp 93 and pressing the unit side plate 41 to the left by the toggle clamp 93 to fix the roller bearing member 46 to the unit side plate 41, ,
The unit side plate 41 does not rattle. Then, a screw 63 is inserted into each screw through-hole 87 of the roller bearing member 46, and a tip of the screw 63 is screwed into a screw hole 65 formed in the unit side plate 41, thereby forming the roller bearing member 4.
6 is fixed to the unit side plate 41.

In the same manner as described above, the unit side plate 4
By attaching the drum bearing member 44 and the roller bearing member 46 also to the unit 2, the attachment of the drum bearing member 44 and the roller bearing member 46 to the unit side plates 41 and 42 is completed. After the attachment of each bearing member to the unit side plates 41 and 42 is completed, the bearing holes 82 of the drum bearing member 44 attached to the unit side plate 41 and the bearing holes 86 of the roller bearing member 46 attached to the unit side plate 42 To
The photosensitive drum 32 is set between the unit side plates 41 and 42 by inserting the end of the rotating shaft 43 of the photosensitive drum 32 respectively. Similarly, the unit side plates 41,
Between 42, the developing roller 36 is set. At this time, the interval D between the rotating shaft 43 of the photosensitive drum 32 and the rotating shaft 45 of the developing roller 36 is constant.

A stirrer 37, a supply spiral 38, and a toner recovery spiral 40 are mounted between the unit side plates 41 and 42. Next, the housing 34 of the developing unit 61 and the housing of the cleaning device 35 are replaced with the unit side plates 41 and 4 in the longitudinal direction of each housing.
The main charger 33 is attached between the unit side plates 41 and 42 so as to be orthogonal to the unit side plate 4.
1 and 42, the image forming unit 3
Is completed.

In the above description, the unit side plate 41
After the drum bearing member 44 is attached and fixed to the unit, the unit side plate 41 is set on the reference device 90 by aligning the bearing hole 82 of the drum bearing member 44 with the first reference pin 96. , The drum bearing member 44 and the roller bearing member 46 may be attached and fixed to the first reference pin 96 and the second reference pin 97, respectively. In short, the drum bearing member 44 and the roller bearing member 46 may be set in accordance with the first reference pin 96 and the second reference pin 97, respectively.

As described above, in the drum bearing member 44 and the roller bearing member 46, the distance d (see FIG. 1) between the peripheral surface of the photosensitive drum 32 and the peripheral surface of the developing roller 36 is appropriate. The first rotation shaft 43 of the photosensitive drum 32 and the first rotation shaft 45 of the developing roller 36 at the time.
By attaching to the unit side plates 41 and 42 in accordance with the reference pin 96 and the second reference pin 97, the interval between the drum bearing member 44 and the roller bearing member 46 can always be constant. Therefore, when the photosensitive drum 32 and the developing roller 36 are supported by these bearing members 44 and 46, the distance d (see FIG. 1) between the peripheral surface of the photosensitive drum 32 and the peripheral surface of the developing roller 36 is appropriate. This is a constant interval, and there is no variation in this interval. Therefore, the supply amount of the toner from the developing roller 36 to the photosensitive drum 32 is constant, and there is no possibility that a problem such as uneven density occurs in the image formed on the sheet.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, a two-component developer containing a toner and a carrier is used as a developer, but a developer including a developing unit using a one-component toner (one-component developer) containing no carrier is used. It may be an image unit.

In addition, various changes can be made within the scope described in the claims.

[0042]

According to the assembling method according to any one of the first to third aspects, when the image forming unit is assembled, the interval between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller is appropriate. This is a constant interval, and there is no variation in this interval. Therefore, the supply amount of the toner from the developing roller to the photosensitive drum becomes constant, and there is no possibility that a problem such as uneven density occurs in the image formed on the paper.

According to the fourth aspect of the present invention, as in the case where the drum unit and the developing unit are separately unitized,
When each unit is incorporated in the image forming apparatus, there is no problem such as a variation in the interval between the photosensitive drum and the developing roller. According to the fifth aspect of the present invention, since the interval between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller is always an appropriate interval, the amount of toner supplied from the developing roller to the photosensitive drum is made appropriate. be able to. Therefore, there is no possibility that a problem such as uneven density occurs in the image formed on the paper.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of a copying machine provided with an image forming unit according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating an external configuration of the image forming unit.

FIG. 3 is a perspective view showing an external configuration of a reference device used when assembling the image forming unit.

FIG. 4 is a sectional view for explaining a method of assembling the image forming unit.

[Explanation of symbols]

 3 Image forming unit 32 Photoreceptor drum 33 Main charger 34 Developing device 35 Cleaning device 36 Developing roller 43, 45 Rotating shaft 44 Drum bearing member 46 Roller bearing member 60 Drum unit 61 Developing unit 90 Reference device 96 First reference pin 97 Second reference Pin 97

Claims (5)

[Claims] An image forming apparatus including a photosensitive drum and a developing roller is provided between a pair of unit side plates to assemble an integrated image forming unit, wherein a rotating shaft of the photosensitive drum and a developing roller is provided. A first step of preparing a unit side plate in which a bearing mounting hole in which a bearing member for receiving each of the bearing members is received is formed, and at least one of the bearing mounting holes can adjust a mounting position of the bearing member; A second step of preparing a reference device in which a first reference pin and a second reference pin respectively corresponding to the rotation axis of the body drum and the rotation axis of the developing roller are erected at predetermined intervals; A third step of setting the unit side plate to the reference device in a state where the bearing member is not mounted in the bearing mounting hole; and the first reference pin and the second reference pin. A fourth step of adjusting the position of the other bearing member attached to the adjustable bearing attachment hole with respect to the one bearing member fixed to the unit side plate by using the A fifth step of removing the unit side plate from the reference device, and a sixth step of attaching and assembling an image forming apparatus including a photosensitive drum and a developing roller between a pair of unit side plates to which each bearing member is attached. Characteristic method of assembling the imaging unit. 2. The image forming unit assembling method according to claim 1, wherein in the third step, one of the bearing members is attached to the unit side plate so that the attached bearing member matches the first reference pin. The unit side plate is set on a reference device, and in the fourth step, the other bearing member is attached in accordance with the second reference pin. 3. The image forming unit assembling method according to claim 1, wherein in the third step, the unit side plate is set on a reference device in a state where no bearing member is mounted in any of the bearing mounting holes. In the four steps, after one of the bearing members is attached to the unit side plate in accordance with the first reference pin, the other bearing member is attached to the unit side plate in accordance with the second reference pin. Assembly method. 4. An image forming apparatus including a photosensitive drum and a developing roller, wherein the image forming apparatus is provided between a pair of unit side plates and is integrated, and a drum bearing for receiving a rotating shaft of the photosensitive drum. And a roller bearing member for receiving a rotating shaft of the developing roller. The drum bearing member and the roller bearing member have a predetermined interval between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller. The image forming unit is attached to the unit side plate. 5. The image forming unit according to claim 4, wherein the drum bearing member and the roller bearing member are attached to the unit side plate and assembled by the method according to any one of claims 1 to 3. .