JP2009181022A - Drum cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drum cartridge which can press a developer roller against a photoreceptor drum even when different types of developing cartridges are mounted, and has good handleability. <P>SOLUTION: A casing 25 for supporting the photoreceptor drum 21 includes a housing portion 25a for housing the developing cartridge 30 for supporting the developing roller 35. A pressing member 40 for pressing a pressed part 32c which is provided to the developing cartridge 30, to press the developing roller 35 against the photoreceptor drum 21 is arranged at the housing part 25a. On the pressing part, a first abutting surface 41b which can be abutted on the first pressed part 32c of the developing cartridge 30 and a second abutting surface 41c which can be abutted on the second pressed part 132c of the developing cartridge 130 are arranged side by side in the direction X of connecting the photoreceptor drum 21 and the housing part 25a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drum cartridge in which a housing that rotatably supports a photosensitive drum is provided with a housing portion that detachably houses a developing cartridge.

  Some image forming apparatuses print on paper using a developer such as toner. In the image forming apparatus, a process unit containing a developer that tends to be consumed is detachably attached to the main body of the image forming apparatus to facilitate maintenance such as replenishment of the developer.

  The process unit is separated into a drum cartridge including the photosensitive drum and a developing cartridge containing the developer due to a difference in the consumption period of the photosensitive drum and the developer. In the drum cartridge or the like, a pressing member is provided in a housing portion that houses the developing cartridge, and a developing roller provided in the developing cartridge is pressed against the photosensitive drum. As a result, when the image forming apparatus performs printing by supplying the developer from the developing roller to the photosensitive drum on which the electrostatic latent image is formed, the amount of the developer adhering to the photosensitive drum is stabilized, and the predetermined amount is obtained. Printing performance can be obtained (see, for example, Patent Document 1).

JP 2000-250378 A

  However, the conventional drum cartridge has poor usability.

  The present invention provides a drum cartridge improved to solve the above problems.

The drum cartridge according to the present invention has the following configuration.
(1) A housing that supports the photosensitive drum is provided in the housing portion that houses the developing cartridge that supports the developing roller, and the pressed portion provided in the developing cartridge by pressing the developing roller. In the drum cartridge having a pressing member that presses the photosensitive drum against the photosensitive drum, the pressing member contacts the first contact surface that can contact the first pressed portion and the second pressed portion. A contactable second contact surface is formed, and the first contact surface and the second contact surface are positioned side by side in a direction connecting the photosensitive drum and the housing portion.

(2) In the invention described in (1), the first and second contact surfaces press the developing roller against the photosensitive drum via the first and second pressed portions. The pressing member is formed so that the forces are equal.

(3) In the invention described in (1) or (2), the pressing member has an opening that opens in a mounting direction in which the developing cartridge is attached to the housing portion, and the first abutting surface; One of the second contact surfaces is formed by a surface that forms the opening.

(4) In the invention according to any one of (1) to (3), the pressing member is swingably supported by the housing and includes the first and second contact surfaces. A moving member, and a biasing member that biases the swinging member to rotate toward the photosensitive drum.

(5) In the invention according to any one of (1) to (4), the pressing member is provided on a second end side of the casing opposite to a first end side supporting the photosensitive drum. The photosensitive drums are arranged symmetrically with a perpendicular passing through the center of the axis of the photosensitive drum and perpendicular to the axis.

  According to the above invention, the usability of the drum cartridge can be improved. For example, when the drum cartridge has only one contact surface that contacts the pressed portion, the user purchases a different type of developing cartridge and attaches it to the housing portion of the housing. Sometimes, the pressing member may not come into contact with the pressed member of the developing cartridge. In such an image forming apparatus using a toner cartridge and a developing cartridge, since the developing roller is not pressed against the photosensitive drum, there is a risk that the developer adhering to the surface of the photosensitive drum is insufficient and printing failure occurs. There is.

  In this respect, the pressing member of the drum cartridge of the present invention includes a first contact surface that can contact the first pressed portion and a second contact surface that can contact the second pressed portion. It is located side by side in the direction connecting the body drum and the accommodating portion.

  Therefore, in the drum cartridge, when the developing cartridge having the first pressed portion is accommodated in the accommodating portion, the developing roller is placed on the photosensitive member by bringing the first contact surface of the pressing member into contact with the first pressed portion. Press against the drum. In the drum cartridge, when the developing cartridge including the second pressed portion is accommodated in the accommodating portion, the developing roller is moved to the photosensitive member by bringing the second contact surface of the pressing member into contact with the second pressed portion. Press against the drum.

  Therefore, for example, when a user mistakes and purchases a developing cartridge having a second pressed portion as a developing cartridge having a first pressed portion and stores the developing cartridge in the receiving portion of the drum cartridge, the first contact surface is Even when not contacting the second pressed portion, the second contact surface contacts the second pressed portion and presses the developing roller against the photosensitive drum. Therefore, according to the drum cartridge of the present invention, even if different types of developing cartridges are accommodated, the developing roller can be pressed against the photosensitive drum, which is convenient.

  In an image forming apparatus using such a drum cartridge, an appropriate amount of developer is supplied from the developing roller of a developing cartridge corresponding to a different model to the photosensitive drum, and the printing performance is stabilized.

  In the drum cartridge, the first contact surface presses the developing roller against the photosensitive drum through the first pressed portion, and the second contact surface passes through the second pressed portion. The first and second abutting surfaces are formed on the pressing member so that the force pressing the surface against the photosensitive drum becomes equal. For this reason, for example, even when a different type of developing cartridge is accommodated in the accommodating portion, the drum cartridge presses the developing roller against the photosensitive drum with the same force as when the appropriate developing cartridge is accommodated in the accommodating portion, and prints. Variations in performance can be eliminated.

  In the drum cartridge, one of the first abutting surface and the second abutting surface is formed by the surface of the pressing member constituting the opening that opens to the developing cartridge side. Therefore, the drum cartridge can form a plurality of contact surfaces on the pressing member with a simple structure.

  In the drum cartridge of the present invention, the swinging member having the first and second contact surfaces is pivotally supported by the housing so as to swing, and the swinging member is biased toward the photosensitive drum by the biasing member. Thus, the pressing member is configured. Such a drum cartridge urges the first pressed part that contacts the first contact surface and the second pressed part that contacts the second contact surface with one urging member. The number of parts constituting the member can be reduced to make the structure of the pressing member compact.

  In the drum cartridge, the pressing member is symmetrically disposed on the rear side opposite to the front side that supports the photosensitive drum with the vertical line passing through the center of the axis of the photosensitive drum and perpendicular to the axis. Therefore, the drum cartridge is configured such that the developing roller is attached to the photosensitive drum in any of the case where the first contact surface is brought into contact with the first pressed portion and the case where the second contact surface is brought into contact with the second pressed portion. Can be pressed with a uniform force in the axial direction.

  Next, an embodiment of a drum cartridge according to the present invention will be described with reference to the drawings.

<Schematic configuration of image forming apparatus>
FIG. 1 is a schematic configuration diagram showing the inside of a laser printer 1 which is an example of an “image forming apparatus”.
In the laser printer 1, a paper feed cassette 3 is detachably attached to a main body casing 2. Sheets 4 are stored in a stacked state in the sheet feeding cassette 3. The printer 1 conveys the paper 4 from the paper feed cassette 3 to the image forming unit 6 by the paper feeding unit 5 as indicated by a one-dot chain line in the drawing, and the paper 4 on which an image is formed in the image forming unit 6 is discharged from the paper discharging unit 7. To the paper discharge tray 2a.

  The image forming unit 6 irradiates laser light from the exposure unit 11 toward the photosensitive drum 21 of the process unit 12 to form an electrostatic latent image on the surface of the photosensitive drum 21. The process unit 12 supplies toner 31 as an example of “developer” to the surface of the photosensitive drum 21 to form a toner image, and sends the paper 4 onto which the toner image has been transferred to the fixing unit 13. The fixing unit 13 heat-fixes the toner image on the paper 4.

  The main casing 2 is provided with an opening 2b on the front surface. The opening / closing member 2c is rotatably supported by the main body casing 2 via the hinge portion 8, and opens and closes the opening 2b. The process unit 12 is detachably attached to the main casing 2 through the opening 2b in order to facilitate maintenance such as replenishment of the toner 31.

<Process unit configuration>
The process unit 12 is separated into a drum cartridge 20 including the photosensitive drum 21 and a developing cartridge 30 that stores toner 31 due to the difference in the consumption period of the consumables. For example, the process unit 12 may attach or detach the developing cartridge 30 after attaching the drum cartridge 20 to the main casing 2, or may attach the drum cartridge 20 to which the developing cartridge 30 has been attached in advance to the main casing 2.

<Configuration of developer cartridge>
The development cartridge 30 includes a development side housing 32 made of resin. The developing-side housing 32 rotatably supports a developing roller 35 that contacts the photosensitive drum 21 when the developing cartridge 30 is mounted on the drum cartridge 20. The development side housing 32 has a supply roller 34 disposed in parallel with the development roller 35. The supply roller 34 contacts the developing roller 35 and rotates in the same direction as the developing roller 35.

  A storage chamber 32 a for storing the toner 31 is formed in the development side housing 32. An agitator 33 is rotatably disposed inside the storage chamber 32a so that the toner 31 is agitated. In the developing-side housing 32, a discharge port 32b for discharging the toner 31 from the storage chamber 32a is opened in parallel with the developing roller 35 and the supply roller 34, and the toner 31 is supplied to the developing roller 35 via the supply roller 34. It has become. The development-side casing 32 includes a blade 36 that scrapes off excess toner 31 adhering to the developing roller 35 to make the thickness of the toner 31 uniform and charge the toner 31.

<Drum cartridge configuration>
On the other hand, the drum cartridge 20 includes a drum-side housing 25 made of resin. A photosensitive drum 21 is rotatably supported on the drum-side housing 25. The drum-side housing 25 is provided with an incident opening 14 long along the axis of the photosensitive drum 21, and irradiates the surface of the photosensitive drum 21 with the laser light of the exposure unit 11.

  In the drum-side casing 25, a charger 22 that charges the surface of the photosensitive drum 21 is disposed next to the incident opening 14. In the drum-side housing 25, a transfer roller 23 is rotatably disposed on the lower side of the photosensitive drum 21 in the drawing. The transfer roller 23 is applied with a transfer device for transferring the toner image onto the paper 4 conveyed between the photosensitive drum 21. Next to the transfer roller 23, a foreign matter removing brush 24 is disposed to remove foreign matter from the photosensitive drum 21.

<Drum cartridge and developer cartridge mounting structure>
FIG. 2 is a view for explaining the mounting of the drum cartridge 20 and the developing cartridge 30 shown in FIG. Note that the description of the drum cartridge 20 and the developing cartridge 30 shown in FIG. 2 is simplified for easy viewing of the drawing. In this embodiment, the developing cartridge 30 is a regular product of the drum cartridge 20. The developing cartridge 130 is a non-genuine product of the drum cartridge 20, and the same configuration as the developing cartridge 30 is described in parentheses in the drawing, and the configuration different from the developing cartridge 30 is described by a two-dot chain line in the drawing. Yes.

  The drum-side housing 25 is open at the top of the portion excluding the upper wall 25c, and is formed with a housing portion 25a so that the developing cartridge 30 can be attached and detached from above. Guide grooves 25b are respectively provided in the left and right side walls 25d and 25d of the housing portion 25a. The guide grooves 25b and 25b guide and slidably support the developing roller shaft 35a protruding from the left and right side walls 32d and 32d of the developing-side housing 32 when the developing cartridge 30 is mounted in the housing portion 25a. The roller 35 is provided so as to be close to the photosensitive drum 21 in parallel.

  In the drum-side housing 25, a pair of pressing members 40 is disposed on the side wall 25g opposite to the front side that supports the photosensitive drum 21 and the housing portion 25a. The pressing member 40 is disposed symmetrically across a perpendicular line L2 that passes through the center of the photosensitive drum 21 in the direction of the axis L1 and is perpendicular to the axis L1. On the left and right side walls 32d, 32d of the development side housing 32, pipe-shaped first pressed portions 32c are erected.

  The developing cartridge 130 is different from the developing cartridge 30 in that the second pressed portion 132c is provided obliquely below the first pressed portion 32c.

<Configuration of pressing member>
FIG. 3 is an enlarged view of a main part around the pressing member 40 shown in FIG. FIG. 4 is a cross-sectional view of the main part for explaining the positional relationship between the pressing member and the pressed member shown in FIG. In FIG. 3 and FIG. 4, the description is simplified to make the drawings easy to see.

  The pressing member 40 is pivotally supported by the drum-side housing 25 so as to be swingable. The swinging member 41 includes first and second contact surfaces 41b and 41c, and the swinging member 41 is rotated toward the photosensitive drum 21. And an urging member 42 that urges the urging member to urge.

  The drum-side housing 25 is provided with a support shaft 25h that pivotally supports the swing member 41. The support shaft 25 h is provided in parallel with the photosensitive drum 21. The swing member 41 is formed with a bearing portion 41e slidably fitted to the support shaft 25h. The bearing portion 41e opens on the side surface of the swing member 41, and the support portion 25h is pushed in and fitted so that the swing member 41 does not fall off the support shaft 25h.

  The urging member 42 is disposed behind the support shaft 25h of the drum-side housing 25 (on the opposite side of the photosensitive drum 21 across the support shaft 25h). The urging member 42 is disposed obliquely so as to tilt the tip portion toward the support shaft 25h. The urging member 42 is always urged so that the tip end portion engages with the spring receiving portion 41 d of the oscillating member 41 and rotates the oscillating member 41 toward the photosensitive drum 21. When the developing cartridges 30 and 130 are not attached to the drum cartridge 20, the swing member 41 comes into contact with the locking projection 25 f erected on the bottom wall 25 e of the drum-side housing 25 and moves toward the rotating drum 21. Rotation is limited.

  The swing member 41 is formed with a first contact surface 41b that can contact the first pressed portion 32c and a second contact surface 41c that can contact the second pressed portion 132c. The first contact surface 41b and the second contact surface 41c are located side by side in the direction X (see FIGS. 1, 2, and 4) that connects the photosensitive drum 21 and the housing portion 25a.

  The first and second contact surfaces 41b and 41c are pressed so that the forces pressing the developing rollers 35 and 135 against the photosensitive drum 21 via the first and second pressed portions 32c and 132c are equal. The swing member 41 of the member 40 is formed.

  Specifically, the swing member 41 has an opening 41a that opens to the developing cartridge 30 (130) side (the side opposite to the bearing portion 41e). The swing member 41 has a first contact surface 41b formed by a surface that forms the opening 41a. The opening 41a is provided with a taper on the inner wall on the biasing member 42 side to widen the opening width so that the first pressed portion 32c can be easily guided into the opening 41a. The first contact surface 41b is provided by this tapered portion. Further, the swing member 41 is provided with a taper on the outer surface on the photosensitive drum 21 side and a second contact surface 41c. The swing member 41 is thickened between the second contact surface 41c and the opening 41a, and is deformed and falls when the second contact surface 41c presses the second pressed portion 132c. Is preventing.

  When the developing cartridges 30 and 130 are accommodated in the accommodating portion 25a, the swing member 41 has the first and second pressed portions 32c and 132c from the center of the support shaft 25h. Tapers for forming the first and second contact surfaces 41b and 41c are provided so that the distances to the portions P1 and P2 that contact the same are equal.

  Further, the taper constituting the first and second contact surfaces 41b and 41c is biased when the first and second contact surfaces 41b and 41c press the first and second pressed portions 32c and 132c, respectively. The member 42 is provided so as to equalize the amount of compression. This is because, even if the drum cartridge 20 accommodates any of the developing cartridges 30 and 130 in the accommodating portion 25a, the pressing force for pressing the developing rollers 35 and 135 against the photosensitive drum 21 is made equal.

<Description of operation>
First, a method for mounting the regular developing cartridge 30 on the drum cartridge 20 will be described.
The user accommodates the developing cartridge 30 in the accommodating portion 25a while inserting both end portions of the developing roller shaft 35a along the guide grooves 25b and 25b of the drum-side housing 25.

  The swing member 41 has the first pressed portion 32c inserted into the opening 41a, and pivots about the support shaft 25h to the opposite side of the photosensitive drum 21 so that the first contact surface 41b is moved to the first pressed portion. 32c. At this time, the urging member 42 is compressed to generate a repulsive force, and the repelling force is transmitted to the developing-side housing 32 through the contact P1 between the first contact surface 41b and the first pressed portion 32c. The developing roller 35 receives the urging force of the urging member 42 via the developing-side housing 32 and is pressed against the photosensitive drum 21.

In this way, the printer 1 including the process unit 12 in which the developing cartridge 30 is mounted on the drum cartridge 20 stabilizes the amount of toner 31 supplied from the developing roller 35 to the photosensitive drum 21, so that the printing performance is stabilized.
When the developing cartridge 130 is mounted on the drum cartridge 20, the swing member 41 has the second pressed portion 132c inserted along the second contact surface 41c, and the photosensitive member centering on the support shaft 25h. It is rotated to the opposite side to the drum 21. At this time, the urging member 42 is compressed to generate a repulsive force, and the repelling force is transmitted to the developing-side housing 132 via the contact point P2 between the second contact surface 41c and the second pressed portion 132c. The developing roller 135 receives the urging force of the urging member 42 via the developing-side housing 132 and is pressed against the photosensitive drum 21.

<Effect>
In the drum cartridge 20 of the present embodiment, the pressing member 40 is provided on the first contact surface 41 b that can contact the first pressed portion 32 c provided on the regular developer cartridge 30, and the non-genuine developer cartridge 130. The second abutting surface 41c that can abut against the second pressed portion 132c is located side by side in the direction X connecting the photosensitive drum 21 and the accommodating portion 25a.

  Therefore, for example, the user mistakenly purchases the non-genuine developer cartridge 130 provided with the second pressed portion 132c as the regular developer cartridge 30 provided with the first pressed portion 32c, and purchased the cartridge 25. Even when the first abutting surface 41b does not abut against the second pressed portion 132c, the developing roller 135 is brought into contact with the second pressed portion 132c even when the first abutting surface 41b does not abut against the second pressed portion 132c. Press against 21. Therefore, according to the drum cartridge 20 of the present embodiment, even when different types of developing cartridges 130 are accommodated in the accommodating portion 25a, the developing roller 35 can be pressed against the photosensitive drum 21, which is easy to use.

  The printer 1 that uses the drum cartridge 20 supplies an appropriate amount of toner 31 from the developing roller 35 of the developing cartridge 130 corresponding to a different model to the photosensitive drum 21, and the printing performance is stabilized.

  Further, in the drum cartridge 20, the force that the first contact surface 41b presses the developing roller 35 against the photosensitive drum 21 via the first pressed portion 32c, and the second contact surface 41c is the second pressed surface. The first and second contact surfaces 41b and 41c are formed on the pressing member 40 so that the force pressing the developing roller 135 against the photosensitive drum 21 via the portion 132c becomes equal. Therefore, for example, even when the developing cartridge 130 of a different model is accommodated in the accommodating portion 25a, the drum cartridge 20 causes the developing roller 135 to move the photosensitive drum 21 with the same force as when the regular developing cartridge 30 is accommodated in the accommodating portion 25a. The variation in printing performance can be eliminated.

  In the drum cartridge 20, a first contact surface 41 b is formed by a surface of the pressing member 40 that forms an opening 41 a that opens toward the developing cartridge 30. Therefore, the drum cartridge 20 can form the contact surfaces 41b and 41c on the pressing member 40 with a simple structure.

  In the drum cartridge 20 of the present embodiment, the swing member 41 including the first and second contact surfaces 41b and 41c is pivotally supported on the support shaft 25h of the drum-side housing 25 so as to be swingable. The pressing member 40 is configured by biasing 41 toward the photosensitive drum 21 by the biasing member 42. In such a drum cartridge 20, the first pressed portion 32c that comes into contact with the first contact surface 41b and the second pressed portion 132c that comes into contact with the second contact surface 41c are each provided with one urging member 42. Since the biasing is performed, the number of parts constituting the pressing member 40 can be reduced and the structure of the pressing member 40 can be made compact.

  The drum cartridge 20 includes a pair of drum-side housings 25 sandwiched by a perpendicular line L2 passing through the center of the axis L1 of the photosensitive drum 21 and perpendicular to the axis L1 on the rear side opposite to the front side supporting the photosensitive drum 21. The pressing members 40 are symmetrically arranged. Therefore, the drum cartridge 20 develops both when the first contact surface 41b is in contact with the first pressed portion 32c and when the second contact surface 41c is in contact with the second pressed portion 132c. The rollers 35 and 135 can be pressed against the photosensitive drum 21 with a uniform force in the axial direction.

In addition, this invention is not limited to the said embodiment, Various application is possible.
In the above embodiment, the pressing member 40 is swingably provided. However, the pressing member 40 is slidably provided, and the position of the contact surface that contacts the first and second pressed portions 32c and 132c can be adjusted with one touch. I did it. On the other hand, you may make it adjust the position of the 1st and 2nd contact surface contact | abutted to the 1st and 2nd to-be-pressed parts 32c and 132c.
In the above embodiment, the opening 41a is provided to form a plurality of contact surfaces. On the other hand, a plurality of convex portions may be provided on the swing member 41, and a plurality of first and second contact surfaces may be provided side by side in a direction connecting the photosensitive drum and the accommodating portion. Moreover, you may provide a some opening part and may comprise a 1st and 2nd contact surface by the surface which comprises each opening part.

1 is a schematic configuration diagram illustrating the inside of an image forming apparatus according to an embodiment of the present invention. It is a figure explaining mounting | wearing of the drum cartridge and developing cartridge shown in FIG. It is a principal part enlarged view of the press member periphery shown in FIG. It is principal part sectional drawing explaining the positional relationship of the pressing member and to-be-pressed member shown in FIG.

Explanation of symbols

20 Drum Cartridge 21 Photosensitive Drum 25 Drum Side Housing 25a Housing 30 and 130 Developer Cartridge 31 Toner (Developer)
32c, 132c Pressed portion 35, 135 Developing roller 40 Pressing member 41 Swing member 41a Opening portion 41b, 41c First and second abutting surfaces 42 Energizing member X Direction L1 connecting the photosensitive drum and the housing portion L2 Axis L2 Perpendicular

Claims (5)

A housing for supporting the photosensitive drum is provided in the housing portion for housing the developing cartridge that supports the developing roller, and presses the pressed portion provided in the developing cartridge to cause the developing roller to move to the photosensitive drum. A drum cartridge having a pressing member that presses against the body drum,
The pressing member is formed with a first contact surface capable of contacting the first pressed portion and a second contact surface capable of contacting the second pressed portion,
The drum cartridge according to claim 1, wherein the first contact surface and the second contact surface are arranged side by side in a direction connecting the photosensitive drum and the housing portion. The drum cartridge according to claim 1, wherein
The drum cartridge according to claim 1, wherein the first contact surface and the second contact surface are formed on the pressing member so that a force pressing the developing roller against the photosensitive drum is equal. The drum cartridge according to claim 1 or 2,
The pressing member has an opening that opens to the developing cartridge side, and one of the first contact surface and the second contact surface is formed by a surface that forms the opening. Drum cartridge. The drum cartridge according to any one of claims 1 to 3,
The pressing member is
A swing member that is swingably supported by the housing and includes the first and second contact surfaces;
A drum cartridge comprising: an urging member that urges the swinging member to rotate toward the photosensitive drum. The drum cartridge according to any one of claims 1 to 4,
The pressing member has a perpendicular line passing through the center in the axial direction of the photosensitive drum and perpendicular to the axis on the second end side of the casing opposite to the first end side supporting the photosensitive drum. The drum cartridge is characterized by being arranged symmetrically.

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