JP4341204B2 - Image forming apparatus, photosensitive drum unit, and method for disassembling photosensitive drum unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine, a printer, and a facsimile, a photosensitive drum unit used in the apparatus, and a method for disassembling the unit.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is known an image forming apparatus that transfers a toner image formed on the surface of a photosensitive drum that is rotatably supported from a photosensitive drum to a sheet at a transfer unit, and fixes the transferred toner image on the sheet. Yes. Here, a conventional example will be described with reference to the drawings. FIG. 12 is a sectional view showing the structure of a conventional photosensitive drum unit. As shown in the figure, the photosensitive drum unit 306 includes a base 302, a photosensitive drum 301, a cleaning unit (not shown), a charging unit, and the like.
[0003]
The base 302 supports both ends of the photosensitive drum 301 via a supporting member 304 having a photosensitive drum bearing 305 and a photosensitive drum bearing 303.
[0004]
The photosensitive drum 301 is disassembled by removing the photosensitive drum bearing 305 and the support member 304 in the reverse Z direction and the Z direction, and then moving the photosensitive drum 301 slightly in parallel with the rotation shaft 301c. 301 is taken out with an inclination with respect to the rotation shaft 301c.
[0005]
[Problems to be solved by the invention]
However, as a problem of the prior art, when exchanging the photosensitive drum 301 for maintenance or the like, the photosensitive drum 301 is supported by the base 302 via the photosensitive drum bearing 303 and the support member 304. As a result, there may be a problem in assembling accuracy and reproducibility of the photosensitive drum unit 306 for positioning the photosensitive drum 301 and the surrounding image forming process, and the structure is complicated. is there.
[0006]
The object of the first invention is to have a simple structure, simple assembly, and high accuracy in fixing the photosensitive drum to the photosensitive drum unit. In particular, when the photosensitive drum is replaced for maintenance or the like, the photosensitive drum unit An object of the present invention is to provide an image forming apparatus capable of ensuring reproducibility of assembly accuracy.
[0007]
The object of the second invention is that the photosensitive drum can be easily taken out, has a simple structure, is easily assembled, and can be fixed to the photosensitive drum unit with high positional accuracy. An object of the present invention is to provide a photosensitive drum unit capable of ensuring the reproducibility of the assembly accuracy of the photosensitive drum unit.
[0008]
A third object of the present invention is to provide a method for disassembling a photosensitive drum unit in which the photosensitive drum can be easily disassembled when replacing the photosensitive drum for maintenance or the like.
[0009]
[Means for Solving the Problems]
The object of the first invention can be achieved by the following means.
[0010]
(1) In an image forming apparatus that rotates a photosensitive drum to transfer a toner image formed on a surface thereof to a sheet, and fixes the transferred toner image on the sheet, the apparatus main body of the image forming apparatus and the apparatus main body The outer periphery is directly fitted in the body-side drum drive shaft for driving the photosensitive drum, the base of the photosensitive drum unit on which the photosensitive drum detachable from the apparatus main body is disposed, and the fitting hole formed in the base. And a photosensitive drum bearing for bearing the photosensitive drum in a radial direction by fitting the inner circumference with flanges at both ends formed on the photosensitive drum, and the main body side drum A photosensitive drum that is coupled to a drive shaft and one flange portion. In the state where a gap is provided between the tip position of the flange portions at both ends in the direction parallel to the rotation axis of the photosensitive drum and the inner wall position of the base body facing the tip position, and the photosensitive drum bearing is removed, The photosensitive drum can be taken out in a direction perpendicular to the rotation axis. An image forming apparatus.
[0011]
The object of the second invention can be achieved by the following means.
(2) In the photosensitive drum unit detachable from the apparatus main body of the image forming apparatus for transferring the toner image formed on the surface by rotating the photosensitive drum to a sheet and fixing the transferred toner image on the sheet, the photosensitive element The outer periphery is directly fitted into the base of the photosensitive drum unit on which the drum is disposed, and the fitting hole formed in the base, and the inner periphery is fitted to the flanges at both ends formed on the photosensitive drum, respectively. A photosensitive drum bearing for bearing the body drum in the radial direction, a flange portion formed at both ends, and a body side drum drive shaft for driving the photoreceptor drum from the device body of the image forming apparatus and one flange portion are coupled A photosensitive drum, In the state where a gap is provided between the tip position of the flange portions at both ends in the direction parallel to the rotation axis of the photosensitive drum and the inner wall position of the base body facing the tip position, and the photosensitive drum bearing is removed, The photosensitive drum can be taken out in a direction perpendicular to the rotation axis. A photosensitive drum unit.
[0012]
The object of the third invention can be achieved by the following means.
(3) a photosensitive drum unit base that is removable from an apparatus main body of an image forming apparatus that rotates the photosensitive drum to transfer a toner image formed on the surface thereof to a sheet and fixes the transferred toner image on the sheet; A photosensitive drum bearing that has a peripheral hole directly fitted in a fitting hole formed in the base and an inner circumference fitted to flanges at both ends formed on the photosensitive drum, and bearings the photosensitive drum in a radial direction; A flange part is formed at both ends, and a drum-side driving shaft for driving the photosensitive drum from the apparatus main body of the image forming apparatus and a photosensitive drum to which one flange part is coupled are provided. A method for disassembling a photosensitive drum unit in which a gap is provided between a tip position of a flange portion at both ends in a direction parallel to an axis and an inner wall position of the substrate facing the tip position, Receiving a taken out in a direction away from the photosensitive drum in a direction parallel to the rotation axis of the photosensitive drum, then, the photosensitive drum The A method of disassembling a photosensitive drum unit, wherein the photosensitive drum unit is separated from the photosensitive drum unit by taking out in a direction orthogonal to the rotation axis.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. Note that the X, Y, and Z directions illustrated in the drawings are the X direction when the color image forming apparatus of the embodiment is viewed from the front, and the left direction is the reverse X direction. Further, when viewed from the front, the upward direction is the Y direction, and the downward direction is the reverse Y direction. Further, the rear direction when viewed from the front is the Z direction, and the front direction is the reverse Z direction.
[0014]
(First embodiment)
First, claims 1 and 2 And 3 An image forming apparatus, a photosensitive drum unit, and a method for disassembling the photosensitive drum unit according to the embodiment will be described. FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an example of an embodiment of the present invention.
[0015]
As shown in FIG. 1, this color image forming apparatus is called a tandem type color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, an intermediate transfer unit 7, and a paper feeding and conveying unit. And fixing means 24. A document image reading device SC is disposed on the upper part of the apparatus main body A of the image forming apparatus.
[0016]
An image forming unit 10Y that forms a yellow image includes a charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, and a primary transfer unit serving as a primary transfer unit arranged around a photosensitive drum 1Y serving as a first image carrier. It has a roller 5Y and a cleaning means 6Y. The image forming unit 10M for forming a magenta image includes a photosensitive drum 1M as a first image carrier, a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit, It has a cleaning means 6M. An image forming unit 10C for forming a cyan image includes a photosensitive drum 1C as a first image carrier, a charging unit 2C, an exposure unit 3C, a developing unit 4C, and a primary transfer roller 5C as a primary transfer unit. It has cleaning means 6C. Further, the image forming unit 10K that forms a black image includes a photosensitive drum 1K as a first image carrier, a charging unit 2K, an exposure unit 3K, a developing unit 4K, a primary transfer roller 5K as a primary transfer unit, and a cleaning unit. 6K.
[0017]
The intermediate transfer unit 7 includes an intermediate transfer body 70 as a second image carrier having a semiconductive endless belt shape that is wound around a plurality of rollers and is rotatably supported.
[0018]
Each color image formed by the image forming units 10Y, 10M, 10C, and 10K is sequentially transferred onto the rotating intermediate transfer body 70 by the primary transfer rollers 5Y, 5M, 5C, and 5K, and is synthesized. Is formed. The sheet P as a recording medium accommodated in the sheet feeding cassette 20 is fed by the sheet feeding unit 21 and passes through a plurality of intermediate rollers 22A, 22B, 22C, 22D and a registration roller 23 to the secondary transfer unit 5A. The color image is transferred onto the paper P at a time. The paper P on which the color image has been transferred is fixed by the fixing unit 24, is sandwiched between the paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus.
[0019]
On the other hand, after the color image is transferred onto the paper P by the secondary transfer means 5A, the residual toner is removed by the cleaning means 6A from the intermediate transfer body 70 which has separated the curvature of the paper P. Residual toner is collected in the box by an apparatus (not shown).
[0020]
During the image forming process, the primary transfer roller 5K is always in pressure contact with the photosensitive drum 1K. The other primary transfer rollers 5Y, 5M, and 5C are in pressure contact with the corresponding photosensitive drums 1Y, 1M, and 1C, respectively, only during color image formation. The secondary transfer unit 5A comes into pressure contact with the intermediate transfer member 70 only when the sheet P passes through the secondary transfer unit 5A and the secondary transfer is performed.
[0021]
FIG. 2 is a perspective view showing a state in which the second process unit 9 is pulled out from the apparatus main body A of the image forming apparatus. The second process unit 9 includes a plurality of intermediate rollers 22A, 22B, 22C, 22D, a registration roller 23, a secondary transfer unit 5A, a fixing unit 24, and the like shown in FIG.
[0022]
3 is a perspective view showing a state in which the first process unit 8 is pulled out from the apparatus main body A of the image forming apparatus, FIG. 4 is a cross-sectional view of the first process unit 8 that houses the image forming unit, and FIG. FIG. 3 is a perspective view of a first process unit 8 that houses an image forming unit.
[0023]
As shown in FIGS. 3, 4, and 5, the first process unit 8 includes image forming units 10 </ b> Y, 10 </ b> M, 10 </ b> C, and 10 </ b> K and an intermediate transfer unit 7.
[0024]
The image forming units 10Y, 10M, 10C, and 10K are arranged in tandem in the vertical direction. An intermediate transfer unit 7 is disposed on the left side of the photosensitive drums 1Y, 1M, 1C, and 1K in the drawing. The intermediate transfer unit 7 includes an endless belt-like intermediate transfer body 70 that can be rotated by winding rollers 71, 72, 73, and 74, primary transfer rollers 5Y, 5M, 5C, and 5K, and a cleaning unit 6A.
[0025]
The first process unit 8 can be pulled out from the apparatus main body A. That is, the front door 101 of the apparatus main body A is opened, and the unit handle members 88L and 88R formed in the first process unit 8 are gripped and pulled out to the front side. The first process unit 8 is guided and slid by the left and right support rails 82L and 82R, and is drawn forward (in the reverse Z direction). The image forming units 10Y, 10M, 10C, and 10K and the intermediate transfer unit 7 are integrally pulled out from the apparatus main body A by the pull-out operation of the first process unit 8.
[0026]
A support rail 82L on the left side of the first process unit 8 in the figure is disposed on the left side of the intermediate transfer body 70 and in an upper space of the fixing unit 24. The support rail 82R on the right side of the first process unit 8 in the drawing is disposed near the lower part of the lowermost developing means 4K. The support rail 82R is disposed at a position that does not hinder the operation of attaching and detaching the developing units 4Y, 4M, 4C, and 4K to the first process unit 8.
[0027]
The right side of the photosensitive drums 1Y, 1M, 1C, and 1K of the first process unit 8 is surrounded by the developing units 4Y, 4M, 4C, and 4K, and the lower side of the drawing is the charging units 2Y, 2M, 2C, and 2K, In addition, the left side of the drawing is surrounded by the intermediate transfer body 70, and the cleaning unit 6Y, 6M, 6C, 6K and the like.
[0028]
Among them, the photosensitive member, the cleaning unit, the charging unit, and the like form one photosensitive drum unit, and the developing unit, the toner replenishing device, and the like form one developing unit. This will be described in detail later.
[0029]
As shown in FIG. 5, the upper space of the photosensitive drum 1 </ b> Y is shielded by a top plate 83 as an upper shielding member fixed to the frame 81 of the first process unit 8. A bottom plate 84 as a lower shielding member fixed to the frame 81 of the first process unit 8 protects the intermediate transfer body 70 when being attached and detached, and also serves as an upper guide plate for the paper conveyance path.
[0030]
6 is an exploded cross-sectional view showing a state in which the intermediate transfer unit 7 and the developing units 4YU, 4MU, 4CU, and 4KU are removed from the first process unit 8. FIG. 7 is a perspective view of the intermediate transfer unit 7. FIG. 4 is a perspective view of a first process unit 8. FIG. In FIG. 7, for convenience of explanation, the left half of the intermediate transfer body 70 is removed to make the inside of the intermediate transfer unit 7 easier to see.
[0031]
6 and 7, with the first process unit 8 pulled out from the apparatus main body A, the intermediate transfer unit 7 is moved slightly to the left in the figure, and then the intermediate transfer unit 7 is gripped and vertically moved. Pull up. The positioning pins 75 (FIG. 7) implanted on the upper side surfaces of the intermediate transfer unit 7 are moved to the left in the drawing along the horizontal grooves 85 (FIG. 8) drilled in the first process unit 8. Then, it is moved vertically upward along the vertical groove 86.
[0032]
When the intermediate transfer unit 7 is lifted, the intermediate transfer unit 7 moves while the positioning pins 75 are regulated by the horizontal grooves 85 and the vertical grooves 86, so that the intermediate transfer body 70 comes into contact with the members of the first process unit 8. Will not be damaged.
[0033]
On the inner surface side of the intermediate transfer body 70, primary transfer rollers 5Y, 5M, 5C, and 5K that are horizontally supported and pressure rollers 76Y, 76M, 76C, and 76K are arranged in a column as shown in FIG. Yes. The lever 77Y that supports the primary transfer roller 5Y and the pressure roller 76Y, the lever 77M that supports the primary transfer roller 5M and the pressure roller 76M, and the lever 77C that supports the primary transfer roller 5C and the pressure roller 76C are regulated. The intermediate transfer member 70 is pressed and released by being simultaneously swung by the plate 78.
[0034]
FIG. 9 is a perspective view of the four photosensitive drum units 11Y, 11M, 11C, and 11K.
[0035]
After the intermediate transfer unit 7 is removed from the first process unit 8, the four photosensitive drum units 11Y, 11M, 11C, and 11K are respectively connected to the pins 93 (FIG. 8) that are suspended from the bases 93Y and 93M. , 93C, 93K and the pin hole 81A (FIG. 8) provided in the frame 81 of the first process unit 8 can be taken out. The uppermost photosensitive drum unit 11Y includes a photosensitive drum 1Y, a charging unit 2Y, and a cleaning unit 6Y. The second-stage photosensitive drum unit 11M includes a photosensitive drum 1M, a charging unit 2M, and a cleaning unit 6M. The third-stage photosensitive drum unit 11C includes a photosensitive drum 1C, a charging unit 2C, and a cleaning unit 6C. Further, the lowermost photosensitive drum unit 11K includes a photosensitive drum 1K, a charging unit 2K, and a cleaning unit 6K.
[0036]
When the first process unit 8 is pulled out from the apparatus main body A, the main body side drum drive shafts AYD, AMD, ACD, and AKD that are cantilevered and supported inside the apparatus main body A shown in FIG. The central holes 1YH, 1MH, 1CH, and 1KH of the drums 1Y, 1M, 1C, and 1K are detached, and the photosensitive drum units 11Y, 11M, 11C, and 11K are fixed to the pin holes 81A of the frame 81 of the first process unit 8. The pin 91 is moved while being suspended through the fitting holes 93A of the base bodies 93Y, 93M, 93C, and 93K. After the movement, the pin 91 is removed from the first process unit 8 and removed. The drum units 11Y, 11M, 11C, and 11K are provided at positions slightly lifted from the restriction positions by the pins 91 on the first process unit 8. Are respectively on the support base (not shown) mounted.
[0037]
In this state, the photosensitive drum unit 11Y can be slid on the support base and moved in the direction of the white arrow shown in FIG. 6, so that the intermediate transfer unit 7 can be taken out from the space after removal. Similarly, the photosensitive drum units 11M, 11C, and 11K can be taken out from the respective support bases.
[0038]
The developing unit 4YU mainly composed of the developing means 4Y facing the photosensitive drum unit 11Y, the developing unit 4MU mainly composed of the developing means 4M facing the photosensitive drum unit 11M, and the developing means 4C opposed to the photosensitive drum unit 11C. The developing unit 4KU mainly composed of the developing unit 4K facing the developing unit 4CU and the photosensitive drum unit 11K is slightly moved from the predetermined storage portion of the first process unit 8 to the right as shown in FIG. It can be taken out by pulling forward (reverse Z direction).
[0039]
The first process unit 8 is slid along the support rails 82L and 82R, mounted in the apparatus main body A, stopped at a predetermined position, and the unit handle members 88L and 88R are rotated by 90 ° to lock the lever (see FIG. (Not shown). The operation detecting means of the first process unit 8 detects by a sensor that detects that the first process unit 8 is mounted at a predetermined position of the apparatus main body A. Alternatively, the case operation detecting means detects that the lock lever has finished a predetermined operation.
[0040]
In the above embodiment, the seamless endless belt-shaped intermediate transfer body 70 has been described. However, the present invention is not limited to this, and the present invention is also applicable to an endless belt-shaped intermediate transfer body having seams. Is possible.
[0041]
The configuration of the color image forming apparatus has been described above. However, the present invention is not limited to the color image forming apparatus, and can be applied to only a monochrome image forming apparatus. There is only one photosensitive drum unit and only one developing unit, and an intermediate transfer member is not required, and the toner image may be directly transferred to a recording sheet as a secondary transfer member.
[0042]
Accordingly, in the following more detailed description, the four photosensitive drum units are exactly the same, so only one set of K will be described.
[0043]
FIG. 10 is a cross-sectional view showing the configuration of the photosensitive drum unit and its periphery in the image forming unit. As shown in FIG. 10, the photosensitive drum unit 11K includes a base 93, a photosensitive drum 1K, photosensitive drum bearings 94a and 94b, bearing pressing plates 95a and 95b, a cleaning unit 6K (FIG. 1), and a charging unit 2K (FIG. 1). ) Etc.
[0044]
The apparatus main body A is the apparatus main body of the image forming apparatus, and the main body side drum drive shaft AKD drives the photosensitive drum 1K from the apparatus main body A. The base body 93 is provided with the photosensitive drum 1K and has a reference fitting hole 93A (FIG. 9). The photosensitive drum 1K has flange portions 1Ka and 1Kb at both ends, and one flange portion 1Kb is coupled to the main body side drum drive shaft AKD.
[0045]
The outer circumferences W of the photosensitive drum bearings 94a and 94b are fitted into two fitting holes 93B of the base 93, respectively, and the inner circumferences of the photosensitive drum bearings 94a and 94b are fitted into the flange portions 1Ka and 1Kb of the photosensitive drum 1K. Each U is fitted. The photosensitive drum bearings 94a and 94b support the photosensitive drum 1K in the radial direction.
[0046]
The gaps L1 and L2 are gaps between the tip positions of the flange portions 1Ka and 1Kb on both sides in the direction parallel to the rotation shaft 1Kc of the photosensitive drum 1K and the inner wall position of the base 93 facing the tip position. With the gaps L1 and L2, the photosensitive drum 1K can be taken out without being tilted in the reverse X direction orthogonal to the rotational axis 1Kc of the photosensitive drum in a state where the photosensitive drum bearing 94a and the photosensitive drum bearing 94b are removed. it can.
[0047]
The photosensitive drum 1K is provided with a gear G1, and a gear G2 meshing with the gear G2 is rotatably provided on the base, so that the photosensitive drum 1K rotates and conveys residual toner on the drum. Yes.
[0048]
Further, in a state where the photosensitive drum unit 11K is housed in the apparatus main body A, one flange portion 1Kb of the photosensitive drum is fitted to the main body side drum drive shaft AKD and is driven with high accuracy during image formation.
[0049]
Here, a method of taking out the photosensitive drum 1K will be described. First, the screws 96 fixing the bearing holding plates 95a and 95b are removed. Next, the photosensitive drum bearing 94a is taken out in the reverse Z direction, and the photosensitive drum bearing 94b is taken out in the Z direction. Thereafter, the photosensitive drum 1K is taken out in the reverse X direction orthogonal to the rotation axis 1Kc of the photosensitive drum. Incorporation of the photosensitive drum 1K into the photosensitive drum unit 11K can be performed by a procedure reverse to the above-described extraction method.
[0050]
As described above, since the photosensitive drum is attached to the substrate via the photosensitive drum bearing, the photosensitive drum can be fixed to the photosensitive drum unit with a simple structure, simple assembly, and high positional accuracy. Further, in a state where the photosensitive drum bearing is removed, the photosensitive drum can be taken out in a direction orthogonal to the rotation axis of the photosensitive drum.
[0051]
( Reference example )
next, Reference example The image forming apparatus and the photosensitive drum unit will be described. Reference example This image forming apparatus is obtained by replacing the photosensitive drum unit with a photosensitive drum unit described later in the image forming apparatus described in the first embodiment.
[0052]
FIG. 11 is a cross-sectional view showing the main configuration of the photosensitive drum unit in the image forming unit. As shown in FIG. 11, the photosensitive drum unit includes a base body 202, a photosensitive drum 201, photosensitive drum bearings 203a and 203b, bearing pressing plates 204a and 204b, cleaning means (not shown), charging means, and the like.
[0053]
A flange portion 201 a and a flange portion 201 b are formed at both ends of the photosensitive drum 201. The base 202 is a skeleton of the photosensitive drum unit, and has two fitting holes 202a and 202b. The outer peripheries of the photosensitive drum bearing 203a and the photosensitive drum bearing 203b are fitted with fitting holes 202a and 202b, respectively, and the inner circumference is fitted with flange portions 201a and 201b. The photosensitive drum 201 is supported in the radial direction by photosensitive drum bearings 203a and 203b.
[0054]
The photosensitive drum 201 is taken out by removing screws fixing the bearing holding plates 204a and 204b, taking out the photosensitive drum bearing 203a in the reverse Z direction, and taking out the photosensitive drum bearing 203b in the Z direction. Thereafter, the photosensitive drum 201 is taken out in the reverse X direction while being slightly inclined with respect to the rotating shaft 201c of the photosensitive drum.
[0055]
As described above, since the photosensitive drum 201 is attached to the base body 202 via the photosensitive drum bearings 203a and 203b, the photosensitive drum 201 is mounted with high positional accuracy with a simple structure and simple assembly. The image forming apparatus and the photosensitive drum unit can be secured to the drum unit. In particular, when the photosensitive drum is replaced for maintenance or the like, the reproducibility of the assembly accuracy of the photosensitive drum unit can be ensured.
[0056]
【The invention's effect】
Since it comprised as mentioned above, there exist the following effects.
[0057]
According to the first aspect of the present invention, there is provided a photosensitive drum unit in which a main body side drum drive shaft for driving the photosensitive drum from the apparatus main body of the image forming apparatus is provided, and the photosensitive drum removable from the apparatus main body is disposed. A photosensitive drum provided with a base, the outer circumference of which is directly fitted in a fitting hole formed in the base, and the inner circumference is fitted to flanges at both ends formed on the photosensitive drum, thereby bearing the photosensitive drum in the radial direction. A bearing is provided, flanges are formed at both ends, and a drum drive shaft on the main body side and a photosensitive drum to which one flange is coupled are provided. A gap is provided between the front end position of the flange portion at both ends in the direction parallel to the rotation axis of the photosensitive drum and the inner wall position of the substrate facing the front end position. Because With the photosensitive drum bearing removed, it can be taken out in the direction perpendicular to the rotational axis of the photosensitive drum, With a simple structure, simple assembly, the photoconductor drum can be fixed to the photoconductor drum unit with high positional accuracy. Especially when the photoconductor drum is replaced for maintenance, etc., the reproducibility of the assembly accuracy of the photoconductor drum unit is ensured. An image forming apparatus that can be used.
[0059]
Claim 2 According to the invention described in the above, the base of the photosensitive drum unit provided with the photosensitive drum is provided, the outer periphery is directly fitted into the fitting hole formed in the base, and the inner circumference is formed at both ends formed on the photosensitive drum. A photosensitive drum bearing that is fitted in the flange portion and bearings the photosensitive drum in the radial direction; a main body side drum drive shaft that forms a flange portion at both ends and drives the photosensitive drum from the apparatus main body of the image forming apparatus; A photosensitive drum to which one flange portion is coupled A gap is provided between the front end position of the flange portion at both ends in the direction parallel to the rotation axis of the photosensitive drum and the inner wall position of the substrate facing the front end position. Because With the photosensitive drum bearing removed, it can be taken out in the direction perpendicular to the rotational axis of the photosensitive drum, With a simple structure, simple assembly, the photoconductive drum can be fixed to the photoconductive drum unit with high positional accuracy, and especially when the photoconductive drum is replaced for maintenance, etc., the reproducibility of the photoconductive drum unit assembly accuracy is ensured. It becomes a photoconductor drum unit that can be used.
[0061]
Claim 3 According to the invention, the photosensitive drum bearing is taken out in a direction away from the photosensitive drum in a direction parallel to the rotational axis of the photosensitive drum, and then taken out in a direction orthogonal to the rotational axis of the photosensitive drum. Since the photosensitive drum is separated from the photosensitive drum unit, the photosensitive drum can be easily disassembled.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an example of an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a state in which a second process unit is pulled out from the apparatus main body of the image forming apparatus.
FIG. 3 is a perspective view illustrating a state in which the first process unit is pulled out from the apparatus main body of the image forming apparatus.
FIG. 4 is a cross-sectional view of a first process unit that houses an image forming unit.
FIG. 5 is a perspective view of a first process unit that houses an image forming unit.
FIG. 6 is an exploded cross-sectional view illustrating a state where an intermediate transfer unit and a development unit are removed from the first process unit.
FIG. 7 is a perspective view of an intermediate transfer unit.
FIG. 8 is a perspective view of a first process unit.
FIG. 9 is a perspective view of four sets of photosensitive drum units.
FIG. 10 is a cross-sectional view illustrating a configuration of a photosensitive drum unit and its periphery in an image forming unit.
FIG. 11 is a cross-sectional view showing a main configuration of another photosensitive drum unit.
FIG. 12 is a cross-sectional view showing a main configuration of a conventional photosensitive drum unit.
[Explanation of symbols]
1Y, 1M, 1C, 1K photoconductor drum
1Kc rotation axis
1Ka, 1Kb Flange
10Y, 10M, 10C, 10K Image forming unit
11Y, 11M, 11C, 11K Photosensitive drum unit
93A Mating hole
93Y, 93M, 93C, 93K Base
94a, 94b, 203a, 203b Photosensitive drum bearing
A Device body
AYD, AMD, ACD, AKD Body side drum drive shaft
L1, L2 clearance

Claims (3)

In an image forming apparatus for rotating a photosensitive drum to transfer a toner image formed on a surface to a sheet and fixing the transferred toner image on the sheet.
An apparatus main body of the image forming apparatus;
A main body side drum drive shaft for driving the photosensitive drum from the apparatus main body;
A substrate of a photosensitive drum unit in which the photosensitive drum detachable from the apparatus main body is disposed;
A photosensitive drum bearing in which an outer periphery is directly fitted in a fitting hole formed in the base, and an inner circumference is fitted to flanges at both ends formed in the photosensitive drum, thereby bearing the photosensitive drum in a radial direction. When,
A flange portion is formed at both ends, and the main body side drum drive shaft and a photosensitive drum with which one flange portion is coupled , and
In a state where a clearance is provided between the tip position of the flange portion at both ends in a direction parallel to the rotation axis of the photosensitive drum and the inner wall position of the base body facing the tip position, and the photosensitive drum bearing is removed, An image forming apparatus, wherein the photosensitive drum can be taken out in a direction perpendicular to the rotation axis . In the photosensitive drum unit removable from the apparatus main body of the image forming apparatus for rotating the photosensitive drum to transfer the toner image formed on the surface to the paper and fixing the transferred toner image on the paper,
A substrate of a photosensitive drum unit in which the photosensitive drum is disposed;
A photosensitive drum bearing for directly bearing the photosensitive drum in a radial direction by fitting an outer periphery directly into a fitting hole formed in the base, and an inner circumference fitted to flanges at both ends formed in the photosensitive drum. ,
A flange portion is formed at both ends, and a main body side drum drive shaft for driving the photosensitive drum from the apparatus main body of the image forming apparatus, and a photosensitive drum to which one flange portion is coupled,
In a state where a clearance is provided between the tip position of the flange portion at both ends in a direction parallel to the rotation axis of the photosensitive drum and the inner wall position of the base body facing the tip position, and the photosensitive drum bearing is removed, A photosensitive drum unit, wherein the photosensitive drum can be taken out in a direction orthogonal to the rotation axis. Rotating the photosensitive drum to transfer the toner image formed on the surface to the paper, fixing the transferred toner image to the paper, the base of the photosensitive drum unit removable from the main body of the image forming apparatus, and forming on the base A photosensitive drum bearing for directly bearing the photosensitive drum in a radial direction by fitting the outer circumference directly into the fitting hole and the inner circumference fitted to the flanges at both ends formed on the photosensitive drum, and flanges at both ends. A main body side drum driving shaft for driving the photosensitive drum from the apparatus main body of the image forming apparatus and a photosensitive drum to which one flange portion is coupled, and parallel to the rotational axis of the photosensitive drum. A method of disassembling the photosensitive drum unit in which a gap is provided between the tip positions of the flange portions at both ends in a certain direction and the inner wall position of the base body facing the tip position,
The photosensitive drum bearing is taken out in a direction away from the photosensitive drum in a direction parallel to the rotation axis of the photosensitive drum,
Next, the method of disassembling the photosensitive drum unit is characterized in that the photosensitive drum is taken out in a direction perpendicular to the rotation axis and the photosensitive drum is separated from the photosensitive drum unit.

Images