JP7106888B2 - drum cartridge - Google Patents

Description

The present invention relates to a drum cartridge to which a developing cartridge is attached and used.

2. Description of the Related Art An image forming apparatus equipped with a process cartridge including a developing cartridge and a drum cartridge is known (see, for example, Japanese Unexamined Patent Application Publication No. 2002-200013).

JP 2017-64970 A

In the process cartridge, the ion wind generated by the corona discharge of the charger flows from the surface of the photosensitive drum to the developing roller, causing the toner to scatter and damage the developing roller and the side seals provided at both ends of the developing roller. can get in between. Since the toner contains a hard component such as silica, in the side seal to which the toner adheres, the sponge portion of the base material may be scraped by the rotation of the developing roller, resulting in toner leakage. In addition, toner leakage may also occur due to the melting of toner adhering to the side seals due to heat.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the flow of ion wind at both ends of a photosensitive drum, thereby suppressing toner scattering.

In order to solve the above-described problems, the drum cartridge according to the present invention includes a frame on which the developing cartridge including a developing roller and side seals provided at both ends of the developing roller can be attached and detached, and a frame rotatably supported by the frame. and a charger supported by a frame for charging the photosensitive drum.
The drum cartridge includes a flexible first sheet attached to the frame at a position facing one end of the photosensitive drum in the axial direction, and a flexible first sheet attached to the frame at a position facing the other end of the photosensitive drum in the axial direction. and an attached flexible second sheet.
The first sheet and the second sheet have portions positioned within the range of the side seals in the axial direction when the developing cartridge is attached.
Further, the first sheet and the second sheet are positioned upstream of the developing roller and downstream of the charger in the rotational direction of the photosensitive drum, and are separated from the surface of the photosensitive drum.

According to this configuration, in a state where the developing cartridge is attached to the drum cartridge, the first sheet and the second sheet are attached to the frame of the drum cartridge at positions opposed to one end portion and the other end portion of the photosensitive drum in the axial direction. Since the sheet overlaps the side seals of the developing cartridge in the axial direction, it is possible to reduce the flow of ion wind generated by the charger and directed from the surface of the photosensitive drum toward the side seals at both ends of the photosensitive drum. Therefore, it is possible to suppress scattering of toner at both end portions of the photosensitive drum and prevent toner from entering between the developing roller and the side seal.

In the drum cartridge described above, the frame is positioned between the charger and the developing roller and has a wall extending in the axial direction, and the first sheet and the second sheet protrude from the wall toward the photosensitive drum. can do.

According to this, the flow of the ion wind passing between the wall extending in the axial direction between the charger and the developing roller and the surface of the photosensitive drum and flowing toward the developing roller is controlled by the first sheet and the second sheet. can be reduced by

In the drum cartridge described above, the first sheet and the second sheet can be configured to be separated from the surface of the photosensitive drum by 0.1 to 1.5 mm.
Further, the distance between the first sheet and the second sheet in the axial direction can be 177 to 237 mm. The interval between the first sheet and the second sheet can be 208 to 217 mm, which is equal to or greater than the width of the print area.

By setting the distance between the first sheet and the second sheet in the axial direction to be equal to or greater than the width of the printing area, the surface of the photosensitive drum has an area exposed to the ion wind and an area not exposed to the ion wind within the printing area. It is possible to suppress the occurrence of unevenness in charging potential.

In the drum cartridge described above, the first sheet and the second sheet may have different widths in the axial direction. For example, the first sheet may have a width of 9 to 36 mm in the axial direction and a width of 12 to 14 mm in the height direction perpendicular to the axial direction. The second sheet may have a width of 11 to 44 mm in the axial direction and a width of 12 to 14 mm in the height direction orthogonal to the axial direction.

In the drum cartridge described above, the thickness of the first sheet and the second sheet can be 0.1 to 0.5 mm. Furthermore, the first sheet and the second sheet can be made of a polyurethane film.

According to this, even if the user accidentally drops the drum cartridge and the frame is bent, the surface of the photosensitive drum is prevented from being damaged by the first sheet and the second sheet attached to the frame. can be prevented.

In the drum cartridge described above, the first sheet and the second sheet may have different shapes. For example, the first sheet has a rectangular shape, the second sheet includes a first rectangular portion and a second rectangular portion, the second rectangular portion having a shape that is axially longer than the first rectangular portion. can do.

In order to solve the above-described problems, a drum cartridge according to the present invention includes a photosensitive drum, a first frame that supports the photosensitive drum, a charger for charging the photosensitive drum, and a second frame that supports the charger. frame and.
The drum cartridge has a flexible first sheet attached to the second frame at a position facing one end of the photosensitive drum in the axial direction, and a position facing the other end of the photosensitive drum in the axial direction, and a flexible second sheet attached to the second frame.
The first sheet has a width of 9 to 36 mm in the axial direction and a width of 12 to 14 mm in the height direction perpendicular to the axial direction.
The second sheet has a width of 11 to 44 mm in the axial direction and a width of 12 to 14 mm in the height direction perpendicular to the axial direction.

According to this configuration, the first flexible sheet and the second flexible sheet are attached to the second frame supporting the charger at positions facing the one end and the other end of the photosensitive drum in the axial direction. In addition, it is possible to prevent the ion wind generated by the charger from flowing outward along the surface of the photosensitive drum at both ends of the photosensitive drum. Therefore, scattering of toner can be suppressed at both ends of the photosensitive drum.

The above-mentioned drum cartridge further includes a cleaning roller for cleaning the surface of the photosensitive drum, the first frame supports the cleaning roller, and the charging device includes the cleaning roller, the first sheet and the second sheet in the rotational direction of the photosensitive drum. It can be a configuration between

In the drum cartridge described above, the first sheet and the second sheet may be separated from the surface of the photosensitive drum by 0.1 to 1.5 mm and made of polyurethane film.

According to this, the distance between the first sheet and the second sheet and the surface of the photosensitive drum can be reduced to make it difficult for the ion wind to flow. On the other hand, even if the user accidentally drops the drum cartridge and the second frame bends, the surface of the photosensitive drum is not damaged by the first and second sheets attached to the second frame. can be prevented.

In the drum cartridge described above, the distance between the first sheet and the second sheet in the axial direction can be 177 to 237 mm. The interval between the first sheet and the second sheet can be 208 to 217 mm, which is equal to or greater than the width of the print area.
Further, in the drum cartridge described above, the first sheet and the second sheet may have different widths in the axial direction. Also, the thickness of the first sheet and the second sheet can be 0.1 to 0.5 mm.
Further, in the drum cartridge described above, the first sheet and the second sheet may have different shapes. For example, the first sheet has a rectangular shape, the second sheet includes a first rectangular portion and a second rectangular portion, the second rectangular portion having a shape that is axially longer than the first rectangular portion. can do.

According to the present invention, it is possible to suppress the scattering of toner by reducing the flow of ion wind at both ends of the photosensitive drum.

1 is a cross-sectional view showing a schematic configuration of a color printer provided with a drum cartridge according to one embodiment; FIG. 3 is a cross-sectional view of the process cartridge; FIG. 4 is a cross-sectional view of a drum cartridge; FIG. 3 is a perspective view of a developer cartridge; FIG. 3 is a perspective view of a drum cartridge; FIG. FIG. 5 is a perspective view showing a second frame of the drum cartridge; 2 is an enlarged cross-sectional view showing a peripheral structure of a photosensitive drum and charger; FIG. It is a schematic diagram showing the shape of the first sheet and the second sheet. FIG. 5 is an explanatory view showing the positional relationship between the side seals and the first and second sheets when the developing cartridge is attached to the drum cartridge;

An embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, the overall configuration of the color printer will be briefly described first, and then the configuration of the process cartridge will be described.
In the following description, the directions are based on the user using the color printer. Specifically, the left side of FIG. 1, which is the front side as viewed from the user, is defined as "front", the right side of FIG. , the back side of the paper surface of FIG. 1 is defined as "left", and the top and bottom of FIG.

As shown in FIG. 1, the color printer 1 mainly includes a paper feeding section 3 and an image forming section 4 within a body housing 2 .
The main housing 2 includes a box-shaped main body frame 21 having an opening at the top, and a main body frame 21 provided above the main body frame 21. The main body frame 21 rotates up and down around a rotation shaft (not shown) on the rear side. It mainly includes an upper cover 22 for opening and closing the opening.

The paper feed unit 3 is provided in the lower part of the main body housing 2 and mainly includes a paper feed tray 31 that stores the paper S and a supply mechanism 32 that supplies the paper S to the image forming unit 4 . The paper feeding section 3 separates the paper sheets S in the paper feeding tray 31 one by one by the feeding mechanism 32 and feeds them onto a conveying belt 73 (described later) of the image forming section 4 .

The image forming section 4 mainly includes four exposure units 41 , four process cartridges 5 , a transfer unit 7 and a fixing device 8 .

The exposure unit 41 is arranged above the photosensitive drum 51 so as to face it, and has a plurality of LEDs (Light Emitting Diodes) (not shown) arranged in the left and right direction at the lower end of the exposure unit 41 . The exposure unit 41 exposes the surface of the photosensitive drum 51 by blinking the LED based on the image data. Also, the exposure unit 41 is held by the upper cover 22 via the holding portion 24 , and moves together with the upper cover 22 to separate from the photosensitive drum 51 when the upper cover 22 is opened.

The process cartridges 5 are arranged side by side in the front-rear direction between the upper cover 22 and the paper feed tray 31, and can be attached to and detached from the body frame 21 when the upper cover 22 is opened. Each process cartridge 5 has a drum cartridge 50 and a developer cartridge 60 .
As shown in FIGS. 2 and 3, the drum cartridge 50 mainly has a photosensitive drum 51 , a scorotron charger 52 and a cleaning roller 53 .
The developing cartridge 60 is configured to be detachable from the drum cartridge 50, and as shown in FIG. It mainly has The toner in the container 64 is supplied to the developing roller 61 by the supply roller 62, and is carried on the developing roller 61 after being regulated to a constant thickness between the developing roller 61 and the layer thickness regulating blade 63. .

Returning to FIG. 1, the transfer unit 7 is provided between the paper feed tray 31 and the process cartridge 5, and mainly includes a driving roller 71, a driven roller 72, a conveying belt 73, and a transfer roller 74. there is The conveying belt 73 is stretched between the driving roller 71 and the driven roller 72, and the photosensitive drums 51 are arranged on the outer surface of the conveying belt 73 so as to face each other. Four transfer rollers 74 are provided corresponding to the photosensitive drums 51 , and are arranged with the conveying belt 73 sandwiched between them and the corresponding photosensitive drums 51 .

The fixing device 8 is provided behind the process cartridge 5 and the transfer unit 7 and mainly includes a heating roller 81 and a pressure roller 82 .

As shown in FIGS. 1 and 2 , the image forming unit 4 charges the surface of the photosensitive drum 51 cleaned by the cleaning roller 53 with the charger 52 and exposes the surface of the photosensitive drum 51 with the exposure unit 41 to expose the surface of the photosensitive drum 51 . to form an electrostatic latent image. As the toner carried on the developing roller 61 is supplied, the photosensitive drum 51 carries on its surface a toner image in which the electrostatic latent image is visualized. After that, the paper S supplied from the paper feeding unit 3 onto the conveying belt 73 is conveyed between the photosensitive drum 51 and the transfer roller 74 to which the transfer bias is applied. The toner image carried thereon is transferred onto the paper S. Then, the toner image is thermally fixed on the sheet S by conveying the sheet S having the toner image transferred between the heating roller 81 and the pressure roller 82 .

The paper S on which the toner image is thermally fixed is discharged onto the paper discharge tray 23 provided on the upper surface of the upper cover 22 by the transport roller 91 and the discharge roller 92 .

Next, the process cartridge 5 will be explained.
As shown in FIG. 4, the developing cartridge 60, which constitutes the process cartridge 5 together with the drum cartridge 50, is located at a position facing both ends in the axial direction of the developing roller 61 (both ends in the axial direction of the peripheral surface of the roller carrying the toner). and has a pair of side seals 65 . The side seals 65 are formed by attaching a surface layer made of non-woven fabric or woven fabric to a base material made of sponge or rubber in order to suppress toner leakage from the developing cartridge 60 . touch.

As shown in FIGS. 3 and 5, the drum cartridge 50 has a frame 55 to which the developer cartridge 60 can be attached and detached. Frame 55 includes a first frame 56 and a second frame 57 .
The first frame 56 is a frame that rotatably supports the photosensitive drum 51 and the cleaning roller 53 and extends in the axial direction. The first frame 56 has a housing portion 58 in which the developer cartridge 60 is mounted. The housing portion 58 is located downstream of the charger 52 in the rotation direction of the photosensitive drum 51 . The photosensitive drum 51 supported by the first frame 56 is exposed toward the accommodating portion 58 .
The second frame 57 is a frame that is close to the photosensitive drum 51 and the cleaning roller 53 and fixed to the first frame 56 . The second frame 57 extends axially and includes a first wall 57A and a second wall 57B supporting the charger 52 .
The first wall 57A is separated from the surface of the photosensitive drum 51 and supports the downstream side of the charger 52 in the rotation direction of the photosensitive drum 51 . The first wall 57A is a wall positioned between the charger 52 and the developing roller 61 in the rotation direction of the photosensitive drum 51 and extending in the axial direction.
The second wall 57B is a wall that is separated from the surface of the photosensitive drum 51 and supports the upstream side of the charger 52 in the rotation direction of the photosensitive drum 51 .

As shown in FIGS. 6 and 7, the first wall 57A has a sticking surface 59 for sticking a first sheet SL and a second sheet SR, which will be described later.
The sticking surface 59 faces the housing portion 58 side, and the first sheet SL and the second sheet SR stuck on the sticking surface 59 face the developing roller 61 with the developing cartridge 60 attached.
The first wall 57A has a flexible first sheet SL attached at a position facing one end of the photosensitive drum 51 in the axial direction (one end in the axial direction of the peripheral surface of the drum on which the photosensitive layer is formed). A flexible second sheet SR is attached at a position facing the other end in the axial direction (the other end in the axial direction of the circumferential surface of the drum).
More specifically, the first sheet SL is attached to the attachment surface 59 located at one end of the first wall 57A of the second frame 57 and protrudes from the first wall 57A toward the photosensitive drum 51 side. The second sheet SR is attached to an attachment surface 59 positioned at the other end of the first wall 57A of the second frame 57, and protrudes from the first wall 57A toward the photosensitive drum 51 side.

Also, the first sheet SL and the second sheet SR are separated by a distance D1 in the axial direction. A distance D1 is the distance between the inner edge of the first sheet SL and the inner edge of the second sheet SR, and is set to 177 to 237 mm.
By setting the distance D1 to 177 mm or more, the surface temperature of the photosensitive drum 51 can be lowered by applying an appropriate amount of ion wind to the photosensitive drum 51 . Further, by setting the distance D1 to 237 mm or less, it is possible to suppress scattering of toner at both ends of the photosensitive drum 51 .
Preferably, the distance D1 is set to 208 mm or more, which is the width of the printing area of the paper S, and is set in the range of 208 to 217 mm.
By setting the distance D1 to be greater than or equal to the print area, the surface of the photosensitive drum 51 has an area exposed to the ion wind and an area not exposed to the ion wind within the print area, thereby suppressing uneven charging potential. Further, by setting the distance D1 to 217 mm or less, it is possible to more appropriately suppress scattering of toner at both ends of the photosensitive drum 51 .

As shown in FIG. 7 , the first sheet SL and the second sheet SR are positioned upstream of the developing roller 61 and downstream of the charger 52 in the rotation direction of the photosensitive drum 51 . The ends of the first sheet SL and the second sheet SR on the side far from the photosensitive drum 51 are adhered to the sticking surface 59 of the first wall 57A with double-sided tape TP so that one end on the side of the photosensitive drum 51 is separated from the photosensitive drum 51 . is fixed with The first sheet SL and the second sheet SR are separated from the surface of the photosensitive drum 51 by a distance D2. The distance D2 ranges from 0.1 to 1.5 mm.

Next, details of the first sheet SL and the second sheet SR will be described.
As shown in FIG. 8(a), the first sheet SL has a rectangular shape. The first sheet SL has a width (horizontal width) L1 of 9 to 36 mm in the axial direction, and a width (height) H1 of 12 to 14 mm in the height direction orthogonal to the axial direction.
As shown in FIG. 8B, the second sheet SR has a shape different from that of the first sheet SL. The second sheet SR has a shape including a first rectangular portion SR1 and a second rectangular portion SR2, and the width L2 of the second rectangular portion SR2 is longer than the width L3 of the first rectangular portion SR1. . The first rectangular portion SR1 protrudes from the second rectangular portion SR2 toward the photosensitive drum 51, and the second rectangular portion SR2 is fixed to the first wall 57A. The second seat SR has a width L2 of 11 to 44 mm and a height H2 of 12 to 14 mm.
The first seat SL and the second seat SR have different widths L1 and L2 due to the shape of the first wall 57A of the second frame 57, and the first rectangular portion SR1 of the second seat SR The width is smaller than that of the seat SL.
By making the width L2 of the second rectangular portion SR2 larger than the width L3 of the first rectangular portion SR1, the second sheet SR has the first wall width of the second sheet SR regardless of the width L3 of the first rectangular portion SR1. A sufficient sticking area for 57A can be secured.

The first sheet SL and the second sheet SR are flexible sheets made of polyurethane film and have a thickness in the range of 0.1 to 0.5 mm.
By using a flexible sheet having such a material and thickness, even if the user accidentally drops the drum cartridge 50 and the second frame 57 is bent, the first sheet SL and the second frame 57 can be bent. It is possible to prevent the surface of the photosensitive drum 51 from being damaged by the sheet SR.

When the developing cartridge 60 is attached to the drum cartridge 50 described above, as shown in FIG. 9, the first sheet SL and the second sheet SR are provided at both axial ends of the developing roller 61 in the axial direction. It covers the range of side seals 65 .
More specifically, in the axial direction, the side seal 65 at one end is positioned within the lateral width L1 of the first seat SL, and the side seal 65 at the other end is positioned within the lateral width of the first rectangular portion SR1 of the second seat SR. Located within the range of L3.

According to the above, the following effects can be obtained in this embodiment.
At the center of the photosensitive drum 51 in the axial direction, the ion wind AF generated by the corona discharge of the charger 52 when the color printer 1 is used flows along the surface of the photosensitive drum 51 toward the developing roller 61 side, and the photosensitive drum 51 moves toward the developing roller 61 side. It works to lower the surface temperature of the drum 51 . On the other hand, at both ends of the photosensitive drum 51 in the axial direction, as shown in FIG. Since the flow AF of the ion wind flowing along the surface toward the developing roller 61 side is reduced, it is possible to suppress scattering of the toner due to the ion wind.
Therefore, it is possible to suppress the toner scattered by the ion wind from entering between the developing roller 61 and the side seal 65 , thereby suppressing toner leakage from the developing cartridge 60 due to deterioration of the side seal 65 .

A second frame 57 of the drum cartridge 50 is positioned between the charger 52 and the developing roller 61 and has a first wall 57A extending in the axial direction. Since it protrudes toward the photosensitive drum 51 side, the flow AF of the ionized wind passing between the first wall 57A and the surface of the photosensitive drum 51 toward the developing roller 61 side is reduced by the first sheet SL and the second sheet SR. be done.
In other words, in the rotation direction of the photosensitive drum 51, the ion wind flow AF generated by the charger 52 positioned between the cleaning roller 53 and the first sheet SL and the second sheet SR flows from the first wall 57A to the photosensitive drum. The first sheet SL and the second sheet SR protruding toward the 51 side make it difficult for the sheet to flow downstream of the photosensitive drum 51 .

By setting the distance (distance D1) between the first sheet SL and the second sheet SR in the axial direction to be greater than or equal to the width of the print area, the ion wind is applied to the surface of the photosensitive drum 51 within the print area. It is possible to suppress the occurrence of unevenness in charging potential due to the existence of areas where there is no charge.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. The specific configuration can be changed as appropriate without departing from the gist of the present invention.

In the above-described embodiment, in the axial direction, the first sheet SL and the second sheet SR cover the side seals 65 provided at both ends of the developing roller 61 in the axial direction. It is sufficient for the SR to have at least a portion positioned within the range of the side seals 65 in the axial direction.
Specifically, in the axial direction, the inner ends of the first seat SL and the second seat SR are positioned inside the inner ends of the pair of side seals 65, and the outer ends of the first seat SL and the second seat SR are positioned inside the inner ends of the pair of side seals 65. It can also be configured to be located inside the outer ends of the pair of side seals 65 .

According to such a configuration, the inner side of the pair of side seals 65 is covered with the first sheet SL and the second sheet SR in the axial direction. can be suppressed. Therefore, it is possible to suppress the occurrence of toner leakage from the toner supply port due to scraping of the base material of the side seal 65 by the adhering toner inside the side seal 65 adjacent to the toner supply port.

Although the present invention is applied to a color LED printer in the above embodiment, the present invention can also be applied to a monochrome LED printer. The present invention can also be applied to other image forming apparatuses such as laser printers, copiers, and multi-function machines.

Moreover, each element described in each of the above-described embodiments and modified examples can be arbitrarily combined for implementation.

50 drum cartridge 51 photosensitive drum 52 (Scorotron type) charger 53 cleaning roller 55 frame 56 first frame 57 second frame 57A first wall 60 developing cartridge 61 developing roller 65 side seal SL first sheet SR second sheet SR1 first Rectangular part SR2 Second rectangular part D1 Distance D2 Distance L1 Width (of first sheet) L2 Width (of second sheet) H1 Height (of first sheet) H2 Height (of second sheet)

Claims (23)

a frame to which a developing cartridge including a developing roller and side seals provided at both ends of the developing roller can be attached and detached;
a photosensitive drum rotatably supported by the frame;
a charger supported by the frame for charging the photosensitive drum;
A drum cartridge comprising
A flexible first sheet attached to the frame at a position facing one end of the photosensitive drum in the axial direction, and the frame at a position facing the other end of the photosensitive drum in the axial direction. a flexible second sheet affixed to the
The first sheet and the second sheet each have a portion positioned within the range of the side seal in the axial direction when the developing cartridge is attached,
The first sheet and the second sheet are positioned upstream of the developing roller and downstream of the charger in the rotation direction of the photosensitive drum, and are separated from the surface of the photosensitive drum. drum cartridge. the frame is located between the charger and the developing roller and has a wall extending in the axial direction;
2. A drum cartridge according to claim 1, wherein said first sheet and said second sheet protrude from said wall toward said photosensitive drum. 3. The drum cartridge according to claim 1, wherein the first sheet and the second sheet are separated from the surface of the photosensitive drum by 0.1 to 1.5 mm. 4. The drum cartridge according to any one of claims 1 to 3, wherein the distance between the first sheet and the second sheet in the axial direction is 177 to 237 mm. 5. The drum cartridge according to claim 4, wherein the interval is equal to or greater than the width of the printing area. 6. The drum cartridge according to claim 5, wherein the interval is 208-217 mm. 7. The drum cartridge according to claim 1, wherein the first sheet and the second sheet have different widths in the axial direction. The first sheet has a width of 9 to 36 mm in the axial direction and a width of 12 to 14 mm in a height direction orthogonal to the axial direction. 1. The drum cartridge according to item 1. The second sheet has a width of 11 to 44 mm in the axial direction and a width of 12 to 14 mm in a height direction orthogonal to the axial direction. 1. The drum cartridge according to item 1. 10. The drum cartridge according to any one of claims 1 to 9, wherein the first sheet and the second sheet have a thickness of 0.1 to 0.5 mm. 11. The drum cartridge according to any one of claims 1 to 10, wherein the first sheet and the second sheet are made of polyurethane film. 12. A drum cartridge according to any one of claims 1 to 11, wherein said first sheet and said second sheet have different shapes. the first sheet has a rectangular shape,
13. The method of claim 12, wherein said second sheet includes a first rectangular portion and a second rectangular portion, said second rectangular portion having a shape that is longer in said axial direction than said first rectangular portion. drum cartridge. a photosensitive drum;
a first frame that supports the photosensitive drum;
a charger for charging the photosensitive drum;
a second frame supporting the charger;
A drum cartridge comprising
A flexible first sheet attached to the second frame at a position facing one end of the photosensitive drum in the axial direction and a position facing the other end of the photosensitive drum in the axial direction, a flexible second sheet attached to the second frame;
The first sheet has a width of 9 to 36 mm in the axial direction and a width of 12 to 14 mm in a height direction orthogonal to the axial direction,
The drum cartridge, wherein the second sheet has a width of 11 to 44 mm in the axial direction and a width of 12 to 14 mm in a height direction orthogonal to the axial direction. further comprising a cleaning roller for cleaning the surface of the photosensitive drum;
The first frame supports the cleaning roller,
15. A drum cartridge according to claim 14, wherein said charger is between said cleaning roller and said first sheet and said second sheet in the rotational direction of said photosensitive drum. The first sheet and the second sheet are
separated from the surface of the photosensitive drum by 0.1 to 1.5 mm,
16. The drum cartridge according to claim 14 or 15, comprising a polyurethane film. 17. The drum cartridge according to any one of claims 14 to 16, wherein the distance between the first sheet and the second sheet in the axial direction is 177-237 mm. 18. A drum cartridge according to claim 17, wherein said interval is equal to or greater than the width of the print area. 19. The drum cartridge according to claim 18, wherein the interval is 208-217 mm. 20. The drum cartridge according to any one of claims 14 to 19, wherein the first sheet and the second sheet have different widths in the axial direction. 21. The drum cartridge according to any one of claims 14 to 20, wherein the first sheet and the second sheet have a thickness of 0.1 to 0.5 mm. 22. A drum cartridge according to any one of claims 14 to 21, wherein said first sheet and said second sheet have different shapes. the first sheet has a rectangular shape,
23. The method of claim 22, wherein said second sheet includes a first rectangular portion and a second rectangular portion, said second rectangular portion having a shape that is longer in said axial direction than said first rectangular portion. drum cartridge.

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