JP5709407B2 - Process cartridge and electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to a process cartridge used in a copying machine, a printer, or the like that employs an electrophotographic system, and an electrophotographic image forming apparatus to which the process cartridge can be attached or detached.

  2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) and process means acting on the photosensitive drum are integrally formed into a cartridge. A process cartridge system is employed in which the cartridge is detachable from the image forming apparatus main body.

  According to this process cartridge system, the maintenance of the image forming apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. For this reason, this process cartridge system is widely used in electrophotographic image forming apparatuses (hereinafter referred to as image forming apparatuses).

  A conventional process cartridge includes a photosensitive drum unit having a cleaning frame for holding a photosensitive drum, a developing roller as a means for developing a latent image on the photosensitive drum, a developing blade, and a developing unit having toner as a developer. It is composed of Further, the photosensitive drum unit and the developing unit are supported so as to be swingable with respect to each other at the swing center. At the time of image formation, the photosensitive drum and the developing roller are in contact with each other, and light from an exposure unit that forms an electrostatic latent image on the photosensitive drum can be irradiated. In addition, the developing roller is pressed against the photosensitive drum by a pressure spring so that the developing roller is surely brought into contact with the photosensitive drum.

  The cleaning means for the process cartridge is for scraping off the transfer residual toner on the photosensitive drum from the surface of the photosensitive drum and collecting it as waste toner. The cleaning means is formed of an elastic member and a sheet metal portion that supports the elastic member, and performs cleaning by bringing the elastic portion into contact with the photosensitive drum. For this reason, the cleaning means is in contact with the photosensitive drum at a predetermined angle and contact pressure. As a support method, a cleaning means fixing seating surface is provided at both ends in the longitudinal direction of the cleaning frame. Generally, the sheet metal part is fixed by means such as screws.

  The cleaning frame has a function to hold the means necessary for other image processes, such as a charging roller, and its shape is complicated, and it is a resin molded product in consideration of mass production and recyclability after use. There are many.

  However, in such means, it is necessary to position the cleaning frame body with high accuracy by elastically deforming the blade of the cleaning means. If the fixing accuracy with respect to the cleaning frame is insufficient, the contact state with the photosensitive drum may not be uniform, resulting in poor cleaning. In view of this problem, a method described in Patent Document 1 is disclosed as a method for obtaining a stable contact state of the cleaning means. Here, in Patent Document 1, a cleaning unit is supported with respect to a photosensitive drum so as to be swingable with respect to a frame of a cartridge, and is urged by an urging member, and when mounted in an image forming apparatus, the cleaning unit. Has been proposed to be unrotatable.

JP-A-6-161328

  However, even when the process cartridge is removed from the image forming apparatus, the blade is fixed to the cleaning frame in a state where it is in contact with the photosensitive drum and elastically deformed. When the process cartridge is transported or stored in a harsh environment, the blade may be plastically deformed and may not exhibit a predetermined cleaning property when actually used by the user.

  The object of the present invention is a further development of the proposal of the prior art, and the object is to prevent the cleaning performance of the process cartridge cleaning means from being deteriorated.

  Another object of the present invention is to provide a process cartridge cleaning means that can stably obtain cleaning properties against temperature changes in the image forming apparatus during transportation and storage.

  Another object of the present invention is to provide a process cartridge capable of reducing the size and cost of the cleaning frame.

  Means for solving the above problems include a process cartridge that is detachable from the electrophotographic image forming apparatus, and includes an electrophotographic photosensitive drum, a frame, and a cleaning unit that removes the developer from the electrophotographic photosensitive drum. A blade that abuts the elastically deformable electrophotographic photosensitive drum, and a support member that supports the blade in an entry direction for allowing the blade to enter the electrophotographic photosensitive drum and a backward direction for retracting the blade. An attachment portion for supporting the frame body so as to be movable, and when the process cartridge is mounted on the apparatus main body of the electrophotographic image forming apparatus, the blade is removed from a pressing member provided on the apparatus main body. A support member having a force receiving portion for receiving the force in the approach direction for pressing against the electrophotographic photosensitive drum. Characterized in that it has a training unit.

  According to the present invention, the cleaning unit is attached to the cleaning frame so as to be movable by a predetermined amount, and the positional relationship between the cleaning unit and the photosensitive drum is defined when the process cartridge is mounted in the image forming apparatus. Thereby, it is possible to suppress the deterioration of the cleaning performance by suppressing the deformation of the blade of the cleaning means during transportation and storage.

It is a main sectional view showing the state of the process cartridge in the embodiment of the present invention. 1 is a cross-sectional view of an image forming apparatus in an embodiment of the present invention. It is a perspective view of the process cartridge in the embodiment of the present invention. It is a disassembled perspective view of the process cartridge in the embodiment of the present invention. It is sectional drawing of the process cartridge in embodiment of this invention. It is sectional drawing of the process cartridge in embodiment of this invention. It is a disassembled perspective view of the process cartridge in the embodiment of the present invention. It is the elements on larger scale of the process cartridge in an embodiment of the invention. It is a disassembled perspective view of the process cartridge in the embodiment of the present invention. It is a disassembled perspective view of the process cartridge in the embodiment of the present invention. 1 is a cross-sectional view of an image forming apparatus in an embodiment of the present invention. 1 is a perspective view of an image forming apparatus in an embodiment of the present invention. 1 is an exploded perspective view of an image forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view of an image forming apparatus in an embodiment of the present invention. 1 is a partial cross-sectional view of an image forming apparatus in an embodiment of the present invention. 1 is a partial cross-sectional view of an image forming apparatus in an embodiment of the present invention.

Example 1
[Overall schematic configuration of image forming apparatus]
FIG. 2 is a schematic cross-sectional view of the color electrophotographic image forming apparatus of this embodiment.

  The image forming apparatus 1 is a four-color full-color laser printer using an electrophotographic process, and forms a color image on a recording medium S. The image forming apparatus 1 is a process cartridge type, and the process cartridge is detachably mounted on the image forming apparatus main body 1A to form a color image on the recording medium S.

  In the following description, regarding the image forming apparatus 1, the front side (front side) is the side on which the opening / closing door 3 is disposed. The rear side (back side) is the opposite side to the front side. The front-rear direction is a direction from the rear side to the front side of the image forming apparatus 1 (front direction) and the opposite direction (rear direction). Left and right are left or right when the image forming apparatus 1 is viewed from the front side. The left-right direction is a direction from left to right (left direction) and the opposite direction (right direction). An image forming apparatus main body (hereinafter referred to as an apparatus main body) is an apparatus component excluding a process cartridge. Regarding the process cartridge, in the longitudinal direction (axial direction) of the electrophotographic photosensitive drum, a side to which driving is transmitted from the apparatus main body is referred to as a driving side, and the opposite side is referred to as a non-driving side.

  Reference numeral 1B denotes a process cartridge housing portion, which is provided inside the apparatus main body 1A. In the container 1B, the first to fourth process cartridges P (PY, PM, PC, PK) are arranged in the horizontal direction from the rear side to the front side of the apparatus main body 1A. Thus, by arranging a plurality of process cartridges (hereinafter referred to as cartridges) P in the horizontal direction, the height of the image forming apparatus 1 can be suppressed. Each cartridge P has the same electrophotographic process mechanism, and the color of the developer (hereinafter referred to as toner) and the amount of toner filling are different. A rotational driving force is transmitted from the apparatus main body 1A side to the cartridge P located in the housing portion 1B. Further, a bias (charging bias, developing bias, etc.) is supplied to the cartridge P from the apparatus main body 1A (not shown).

  As shown in FIG. 2, each cartridge P of the present embodiment has an electrophotographic photosensitive member unit (hereinafter referred to as a photosensitive drum unit) 8. The photosensitive drum unit 8 includes an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) 4, and a charging unit 5 and a cleaning unit 7 as process units that act on the photosensitive drum 4. Each cartridge P includes a developing unit 9 having a developing unit that develops the electrostatic latent image on the photosensitive drum 4. The photosensitive drum unit 8 and the developing unit 9 are coupled to each other so as to be swingable. A charging roller 5 is used as the charging means. The cleaning means 7 is used as the cleaning means. A developing roller 6 is used as the developing means. A more specific configuration of the cartridge P will be described later.

  The first cartridge PY contains yellow (Y) toner in a developing container, and forms a Y-color toner image on the surface of the photosensitive drum 4. Similarly, the second cartridge PM contains magenta (M) toner in the developing container. Further, the third cartridge PC contains cyan (C) toner in the developing container. The fourth cartridge PK contains black (K) toner in the developing container. Then, each color toner image is formed on the surface of the photosensitive drum 4.

  Above the cartridge P (PY / PM / PC / PK), a laser scanner unit LB as an exposure unit is disposed. The laser scanner unit LB outputs a laser beam L corresponding to the image information. The laser light L passes through the exposure window 10 of the cartridge P and scans and exposes the surface of the photosensitive drum 4.

  An intermediate transfer belt unit 11 as a transfer member is disposed below the cartridge P (PY / PM / PC / PK). The intermediate transfer belt unit 11 includes a flexible endless transfer belt 12, a driving roller 13 that stretches and rotates the transfer belt 12, a turn roller 14, and a tension roller 15. The lower surface of the photosensitive drum 4 of each cartridge is in contact with the upper surface of the transfer belt 12. The contact portion is a primary transfer portion. A primary transfer roller 16 is disposed inside the transfer belt 12 so as to face the photosensitive drum 4. A secondary transfer roller 17 is disposed in contact with the driving roller 14 via the transfer belt 12. A contact portion between the transfer belt 12 and the secondary transfer roller 17 is a secondary transfer portion.

  A feeding unit 18 is disposed below the intermediate transfer belt unit 11. The feeding unit 18 includes a tray 19 on which the recording medium S is stacked and stored, a feeding roller 20, and the like.

  A fixing unit 22 and a discharge unit 23 are disposed above the rear side in the apparatus main body 1A. The upper surface of the apparatus main body 1A is a discharge tray 24.

  The operation for forming a full-color image is as follows. The photosensitive drums 4 of the first to fourth cartridges P (PY, PM, PC, PK) are driven to rotate at a predetermined speed in the counterclockwise direction indicated by the arrow. The transfer belt 12 is also rotationally driven at a speed corresponding to the speed of the photosensitive drum 4 in the clockwise direction of the arrow (forward direction with respect to the photosensitive drum rotation). The laser scanner unit LB is also driven. In synchronization with this drive, the charging roller 5 uniformly charges the surface of the photosensitive drum 4 to a predetermined polarity and potential in each cartridge. The laser scanner unit LB scans and exposes the surface of each photosensitive drum 4 with a laser beam L in accordance with each color image signal. As a result, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 4. The formed electrostatic latent image is developed by the developing roller 6 that is rotationally driven at a predetermined speed in the clockwise direction of the arrow.

  By the electrophotographic image forming process operation as described above, a Y color toner image corresponding to the yellow component of the full color image is formed on the photosensitive drum 4 of the first cartridge PY. Then, the toner image is primarily transferred onto the transfer belt 12.

  Similarly, the toner images of the second cartridge PM, the third cartridge PC, and the fourth cartridge PK are superimposed on the transfer belt 12, and a four-color full-color unfixed toner image is formed.

  In each cartridge, residual toner remaining on the surface of the photosensitive drum 4 after the primary transfer is removed by the cleaning unit 7.

  On the other hand, one recording medium S is separated and fed at a predetermined control timing. The recording medium S is introduced into a secondary transfer nip portion that is a contact portion between the secondary transfer roller 17 and the transfer belt 12 at a predetermined control timing. As a result, the four color superimposed toner images on the transfer belt 12 are sequentially transferred onto the surface of the recording medium S in the course of the recording medium S being conveyed through the nip portion.

  The recording medium S is separated from the surface of the transfer belt 12 and introduced into the fixing unit 22. Then, it is heated and pressurized at the fixing nip portion. As a result, each color toner image is fixed to the recording medium S. Then, the recording medium S exits the fixing unit 22 and is discharged onto the tray 24 by the discharge unit 23 as a full-color image formed product.

[Overall configuration of cartridge]
In this embodiment, the first to fourth cartridges P (PY, PM, PC, PK) have the same electrophotographic process mechanism, and the toner colors and toner filling amounts are different. It is.

  As shown in FIGS. 3 to 5, the cartridge P (PY / PM / PC / PK) is a horizontally long assembly whose longitudinal direction is the direction of the rotation axis a of the photosensitive drum 4, and is viewed from the front of the apparatus main body. The right side is the driving side and the left side is the non-driving side. The cartridge P includes a photosensitive drum unit 8, a developing unit 9, a driving side cover member 31, and a non-driving side cover member 32.

  As shown in FIG. 6, the photosensitive drum unit 8 includes a photosensitive drum 4, a charging roller 5, and a cleaning unit 7 in a cleaning container 33 serving as a first frame.

  As shown in FIGS. 4 and 7, the photosensitive drum 4 has a photosensitive drum support 51L of the non-driving side cover member 32 on the non-driving side and a photosensitive drum supporting portion of the driving side cover member 31 on the driving side. It is rotatably supported by 51R. As shown in FIG. 3, a drum drive coupling (drive transmission unit) 36 as a photoconductor drum drive input unit is coaxial with the axis a of the photoconductor drum 4 at the drive side end of the photoconductor drum 4. It is attached with.

  A coupling (not shown) as a drum drive output unit on the apparatus main body side is engaged with the drum drive coupling 36 to transmit a driving force of a drive motor (not shown) of the apparatus main body. Then, the photosensitive drum 4 is rotationally driven at a predetermined speed counterclockwise in FIG. The charging roller 5 is a contact charging type charging member that contacts the drum 1 and rotates following the drum 1.

  As shown in FIG. 5, the cleaning means 7 includes an elastically deformable elastic blade (hereinafter referred to as a blade) 7b and a support metal plate 7a as a support member. The tip of the blade 7b is disposed in contact with the rotational direction of the photosensitive drum 4 in the counter direction. The cleaning unit 7 serves to remove the toner remaining on the photosensitive drum 4. The transfer residual toner removed from the peripheral surface of the photosensitive drum 4 by the cleaning unit 7 is accommodated in a removed toner collecting portion 33 a in the cleaning container 33.

  The developing unit 9 includes a developing container 34 as a second frame, a developing roller 6 as a developing unit, and a developing blade 38. The developing container 34 includes a toner container 39 and a developing chamber 40.

  The developing blade 38 is disposed such that its tip is in contact with the rotation direction of the developing roller 6 (clockwise in FIG. 6) in the counter direction. The developing blade 38 serves to restrict the toner to a thin layer on the peripheral surface of the developing roller 6.

  A driving input gear is disposed at the driving side end of the developing unit 9 (not shown). The driving force from the image forming apparatus 1 is transmitted to the developing roller 6 through the driving input gear from the developing driving coupling 46 (see FIG. 3) provided on the end face of the driving input gear. It is rotationally driven in the direction of the arrow G.

  As shown in FIG. 7, a cylindrical boss 49 is provided on the outer surface of the non-driving side plate 34L of the developing container 34. The boss 49 is on the rotation axis b of the drive input gear. The rotation axis b is parallel to the rotation axis a of the photosensitive drum 4. The rotation axis b is a swing axis of the developing unit 9.

  As shown in FIGS. 3 and 4, the drive-side cover member 31 is provided with a cylindrical receiving hole 54 into which a cylindrical portion (not shown) of the side cover 47 of the developing unit 9 is fitted. Further, a boss 55 for determining the mounting posture of the cartridge P in the apparatus main body is provided on the outer surface of the drive side cover member 31. Further, a driven-side positioning portion 56R is provided on the lower edge portion of the driving-side cover member 31 so as to project a cartridge P, which will be described later, to a positioning portion on the apparatus main body side.

  As shown in FIG. 4, the inner surface of the non-driving side cover member 32 is provided with a shaft 58 that fits into the cylindrical hole corresponding to the cylindrical boss 49 on the non-driving side of the developing unit 9. Further, a groove portion 60 is provided on the outer surface of the non-driving side cover member 32 so that the mounting posture of the cartridge in the apparatus main body does not fall greatly. Further, a non-driving side positioned portion 56L is provided on the lower edge portion of the non-driving side cover member 32 so as to project a cartridge, which will be described later, to a positioning portion on the apparatus main body side.

  The driving frame and the non-driving side of the drum unit 8 and the developing unit 9 are respectively associated with the cover members 31 and 32 on the driving side and the non-driving side, and the cleaning frame 33 is supported while rotatably supporting the photosensitive drum. It is fixed by means such as screws. Therefore, the cover members 31 and 32 are integrated with the cleaning frame 33 to form a frame of the photosensitive unit 8.

  The developing unit 9 is rotated about a swing center 62 shown in FIG. 5 (corresponding to the axis b in FIG. 3 or FIG. 4) in a direction D in which the developing roller 6 contacts the drum 4. It is always biased by a pressure spring (not shown) which is a biasing member.

  At the time of image formation, the photosensitive drum 4 and the developing roller 6 are kept in contact with each other and rotated at a predetermined speed to perform image formation.

[Supporting method of cleaning means]
Hereinafter, a method of supporting the cleaning unit 7 on the cleaning frame 33, which is a main part of the present invention, will be described. In the following description, the support position of the cleaning unit 7 when the image formation is performed in the image forming apparatus 1 will be considered as a reference. As shown in FIG. 6, the direction in which the cleaning unit 7 enters the photosensitive drum 4 in the cross-sectional direction is defined as the −Y direction, and the direction in which the cleaning unit 7 moves backward is defined as the Y direction. Further, a direction orthogonal (crossing) to the Y direction is taken as an X direction.

  The elastic blade 7b of the cleaning means 7 has a ridge 7c (see FIG. 7) in contact with the photosensitive drum 4 at a predetermined pressure and a predetermined angle. As the photosensitive drum 4 rotates (in the direction of arrow E in the figure), the blade 7b scrapes off the transfer residual toner adhering to the surface of the photosensitive drum 4, and the scraped toner is used as waste toner in the cleaning frame 33. It is stored in the waste toner storage chamber 33a.

  In this embodiment, the blade 7b is made of a material such as urethane rubber, and the support sheet metal 7a is a galvanized steel plate. Further, the ridge line portion 7c of the cleaning means 7 that contacts the photosensitive drum 4 of the blade 7b has a uniform linear shape in the longitudinal direction, and maintains a uniform scraping property, that is, a cleaning property with respect to the photosensitive drum 4. Is possible.

  On the other hand, the blade 7 b of the cleaning unit 7 collects the transfer residual toner on the photosensitive drum 4. For this reason, at least in the main scanning direction of the image forming apparatus, that is, in the longitudinal direction of the photosensitive drum 4, the dimension is sufficient to cover the toner coat area of the developing roller 6 determined from the printable area.

  Further, the support sheet metal 7a of the cleaning means 7 has an L-shaped bent portion 7d over the entire length. The support metal plate 7 a changes its shape on the outer side of the blade 7 b and extends to the outside of the cleaning frame 33. The longitudinal ends 7e and 7f of the bending portion 7d are force receiving portions that receive a pressing force from the image forming apparatus in the -Y direction during image formation, as shown in FIGS. 7g and 7h, which are orthogonal surfaces of the bent portions 7e and 7f, are engaged with the image forming apparatus 1A in the X direction to serve as positioning portions during image formation, and the end surface 7p of the support metal plate 7b. Is a positioning portion in the -Y direction during image formation.

[How to fix the cleaning means to the cleaning frame]
Next, a fixing method for fixing the cleaning means 7 to the cleaning frame 33 will be described.

  In this embodiment, the cleaning means 7 is attached to the cleaning frame 33 with a certain backlash, and can move a certain amount in the X direction relative to the cleaning frame 33 when the cartridge is a single unit.

  First, positioning to the cleaning frame 33 in the -Y direction will be described with reference to FIG. Although the non-drive side is illustrated in FIG. 8, the drive side has the same configuration. Near both ends in the longitudinal direction of the support sheet metal 7a of the cleaning means 7, there are provided first defining portions 7j for defining the position of the cleaning means 7 in the -Y direction during image formation. The defining portion 7j has a certain length, and has a concave shape having a predetermined width L1 in the Y direction. On the other hand, the cleaning frame 33 has a regulating portion 33b of the cleaning frame 33 at a position corresponding to the defining portion 7j of the cleaning means 7. The restricting portion 33b of the cleaning frame 33 is a convex resin molded product having a surface at a position corresponding to the defining portion 7j of the cleaning means and a position having a width L2 narrower than the width L1 of the cleaning means. In the case of the present embodiment, the difference between the defined portion dimension L1 and the width L2 of the restricting portion of the cleaning frame is set to 0.5 mm. That is, the restricting portion 33b restricts the cleaning unit 7 from moving a predetermined amount or more in the -Y direction.

  Next, the positioning to the cleaning frame 33 in the X direction and the method of holding the cleaning means will be described with reference to FIGS. The X direction is also described on the non-driving side, but the configuration is the same on the driving side.

  The cleaning frame 33 is formed with a seating surface 33 d for supporting the cleaning means 7. The position of the seating surface 33d is set to a position where the cleaning means 7 has a predetermined set pressure and angle during image formation. The cleaning means 7 is held in a state having a certain gap with respect to the seating surface 33 d of the cleaning frame 33 using screws 90 as fastening members. As a means for this, a pilot hole 33f for a screw is provided in the seating surface 33d. Here, the depth of the pilot hole 33f for the screw is set to be 0.4 mm shorter than the total thickness of the nominal length of the screw to be used and the thickness of the support sheet metal 7a of the cleaning means 7. Further, in order to define the longitudinal positions of the cleaning frame 33 and the cleaning means 7, the cleaning means 7 is provided with an oblong hole 7m, and the cleaning frame 33 is provided with a boss 33g.

  A method of holding the cleaning means 7 on the cleaning frame 33 is performed as follows. First, the oblong hole 7m of the cleaning means 7 is aligned with the boss 33g of the cleaning frame 33 and temporarily placed on the seat surface 33d. Thereafter, the screw 90 is attached to the pilot hole 33f provided on the seating surface 33d, and the cleaning means 7 is held. Here, when the support metal plate 7a of the cleaning means 7 is fixed to the cleaning frame 33 with the screw 90, the screw 90 abuts at the bottom of the screw lower hole 33f, but the total screw length is the same as that of the screw lower hole 33f as described above. It is longer than the depth and thickness of the support sheet metal 7a. Therefore, it is held with a gap of about 0.4 mm between the cleaning means 7 and the seat surface 33d (L4 portion in FIG. 6). Further, since there is a gap between the support metal plate 7a and the cleaning frame 33 in the Y direction, the cleaning means 7 is held in a state where there is a backlash in both the X direction and the Y direction.

  The contact pressure of the cleaning unit 7 against the photosensitive drum 4 is generated by causing the blade 7b of the cleaning unit 7 to enter the photosensitive drum 4 by a predetermined amount. In the present embodiment, the amount of penetration of the blade 7b during image formation is set to 1.0 to 1.5 mm.

  Further, the dimension of the positioning portion in the -Y direction of the cleaning means 7 is about 30 mm from the point where the blade 7b contacts the photosensitive drum 4, and the dimension of the positioning portion in the X direction is 2.0 to 3.0 mm. . The outer diameter of the photosensitive drum 4 is φ24. Here, as described above, the cleaning means 7 is held on the cleaning frame 33 with a backlash of 0.8 mm and 0.4 mm respectively in the X direction and the Y direction. Then, as shown in FIG. 1, the blade 7 b is rotated in the direction of arrow F by the force received from the photosensitive drum 4 by the above-described play. In the cartridge P alone, the blade 7b is in contact with the surface of the photosensitive drum 4, but is hardly elastically deformed.

  The screw 90 used in this embodiment is a so-called self-tapping screw that forms a screw groove by tightening into a prepared hole of a resin molded product.

[Cleaning unit seal configuration]
Next, the seal configuration of the cleaning unit 8 will be described. The cleaning unit 8 has the cleaning frame 33 and other components necessary for the electrophotographic process in the cleaning frame 33, and a part of the cleaning frame 33 includes a storage chamber 33a for collecting and storing the transfer residual toner. It has become.

  Therefore, in order to prevent the toner collected from the cleaning means 7 from leaking out of the storage chamber 33a, sealing is performed by the sealing member.

  The seal configuration in the present embodiment is as follows.

  FIG. 9 shows a seal configuration of the cleaning unit 8. The seal member includes a longitudinal seal member 63, an end seal member 64, an auxiliary seal member 65, and a seating surface seal member 66. The longitudinal seal member 63 seals the gap between the support metal plate 7 a and the cleaning frame 33 along the longitudinal direction of the cleaning means 7. The end seal member 64 seals between the elastic blade 7b and the support sheet metal 7a and the photosensitive drum 4 at one end side and the other end side in the longitudinal direction. The auxiliary seal member 65 seals between the end seal member 64 and the cleaning frame 33. Further, the seat seal member 66 seals between the cleaning means 7 and the periphery of the cleaning means support seat surfaces 33 d and 33 e of the cleaning frame.

  The configuration of each seal member is as follows.

  The longitudinal seal member 63 is made of urethane foam or the like, is made of a material that has elasticity and has excellent followability with respect to the gap, and is fixed to a seal seat surface 33h provided on the cleaning frame 33 by a fixing means such as a double-sided tape. Has been. In the configuration of the present embodiment, urethane foam (trade name: Moltoprene SM-55) having a thickness of 4 mm is compressed and used. The amount of compression is set to be 2.0 mm during image formation.

  Here, the sealing performance by urethane foam will be described. Sealing with urethane foam compresses the urethane foam at the portion in contact with the toner. Thereby, the invasion of the toner is prevented by reducing the size of each cell constituting the urethane foam. Furthermore, at the boundary between the urethane foam and the mating part (boundary between the support sheet metal 7a), the open surface of each cut cell is compressed, and the intrusion of toner is prevented by being below a certain size. Further, the sealing property represents the performance against the toner leaking out of the sealing member. That is, not only the physical properties and usage of the seal member itself but also the state of the surrounding toner, for example, when the toner is actively flowing or when the low-fluidity toner is in a stationary state, etc. Is.

  In the present embodiment, as a condition for ensuring the sealing performance in the cleaning unit 8, if the compression ratio of the urethane foam, that is, the dimensional ratio of the sealing member alone to the dimension under the usage condition is 70% or less, the sealing member is used. Function.

  Therefore, in the present embodiment, as described above, since the size of the longitudinal seal member 63 at the time of image formation is 2.0 mm, and the size of a single product is 4.0 mm, the compression rate is 50%. On the other hand, the cartridge P alone has a backlash of 0.4 mm in the X direction. For this reason, the longitudinal seal member 63 has an average thickness of 2.4 mm (the value is not uniform due to the inclination of the cleaning means supporting sheet metal 7a). Therefore, the compression rate in this state is 60%. Sex is ensured.

  Next, the configuration of the end seal member 64 will be described.

  The cleaning means 7 at the end in the longitudinal direction has a larger size of the elastic blade 7b than the support sheet metal 7a. This is because the elastic blade 7b is formed by molding. The elastic blade 7b has a stepped portion in the cross-sectional direction with respect to the support metal plate 7a. Therefore, the end seal member 64 needs to reliably seal these gaps at the end in the longitudinal direction. The photosensitive drum 4 rotates in the direction of arrow E shown in FIG. 6 during image formation, and the elastic blade 7b cleans the surface of the photosensitive drum while following the surface of the photosensitive drum 4. For this reason, the end seal member 64 also needs to be slidable with respect to the photosensitive drum 4 and the elastic blade 7b.

  In order to satisfy such conditions, in the present embodiment, the end seal member 64 is made of urethane foam affixed to the surface layer of the nonwoven fabric, and the auxiliary seal member 65 is affixed with double-sided tape on one side of the urethane foam. The thing is adopted.

  The sticking state of each seal is as shown in FIG. 9 and FIG.

  A seating surface 33 h for attaching each seal member is formed on the cleaning frame 33. First, the auxiliary seal member 65 is attached in this state. The double-sided tape of the auxiliary seal member 65 is used and fixed to the cleaning frame 33.

  Next, the end seal member 64 is attached so as to cover the auxiliary seal member 65. The attachment position of the end seal member 64 is performed according to the attachment position of the cleaning means 7. That is, as shown in FIG. 8, when the cleaning means 7 is attached, the edge portion 64a of the end seal member 64 is set to be compressed by 0 to 1.0 mm with respect to the edge portion 7c of the cleaning means.

  Further, the seating surface seal member 65 is affixed around the seating surface 33 of the cleaning frame, and is affixed so as to contact the end seal member 64 and the longitudinal seal member 63 or to compress the respective seals. The

  Here, as in the previous description, the sealing performance in the state of the cartridge P alone, that is, the state in which the cleaning unit 7 has a backlash with respect to the cleaning frame 33 will be described. At the time of image formation, the end seal member 64 has the urethane foam portion compressed, and the nonwoven fabric of the surface layer portion follows the photoreceptor drum 4 and the elastic blade 7b. Also, the auxiliary seal member 64 is compressed in the same manner, and is in close contact with the cleaning means support metal plate 7b to have a sealing property.

  Here, in the cartridge P alone, since the cleaning unit 7 has a backlash with respect to the cleaning frame 33, each seal member is compressed in a direction in which the contact pressure of the elastic blade 7b escapes, that is, compared with the time of image formation. Load is applied in the direction. In the present embodiment, the urethane foam of the end seal member 64 is made of the same material as described above, the thickness is 3.0 mm, and the thickness at the time of image formation is 2.5 mm including the surface layer. It is set to be. Further, the seating surface seal 66 is made of the same material and has the same thickness as the longitudinal seal 63, and the thickness at the time of image formation is set to 2.0 mm. The auxiliary seal member 65 is made of low-resilience urethane foam and has a thickness of 3.0 mm.

  In the cartridge P alone, each seal member is subjected to a load in the compression direction as compared with the time of image formation, but the sealability at each portion is in the direction of improving, and sufficient sealability can be obtained.

  With the configuration of the sealing member as described above, the sealing performance is impaired even when the cleaning means 7 is installed with a backlash relative to the cleaning frame 33 by appropriately setting the material and compression rate of each sealing member. There is nothing.

[Installation of cartridge in image forming apparatus]
Next, an operation for mounting the cartridge P to the image forming apparatus 1 will be described. The description will be given on the non-driving side of the image forming apparatus, but the driving side has the same configuration.

  As shown in FIG. 2, in the apparatus main body of the present embodiment, the cartridge P is replaced by pulling out the cartridge P (PY / PM / PC / PK) for improving usability. A plurality of moving members are supported. Then, the cartridge P is pulled out to the front side of the apparatus main body together with the cartridge tray 29 and replaced. That is, as shown in FIG. 11, when the cartridge tray 29 is pulled out to the outermost side of the apparatus main body 1A, all the cartridges P (PY / PM / PC / PK) come out from the inner side of the apparatus main body 1A. . Therefore, when the user replaces the cartridge with respect to the cartridge tray 29, it is easy to perform the replacement operation.

  Next, attachment of the cartridge to the image forming apparatus will be described.

  As shown in FIG. 2 or FIG. 11, an opening 26 through which the cartridge passes is provided on the front side of the apparatus body 1A in order to insert the cartridge into the apparatus body 1A and to remove the cartridge from the apparatus body 1A. is there. An open / close door 3 is provided that is movable between a closed position for closing the opening 26 and an open position for opening the opening 26.

  The open / close door 3 is a part of the appearance of the image forming apparatus 1. The open / close door 3 is also an operation unit that positions the process cartridge P inside the image forming apparatus 1 and sets the process cartridge P to a position where the image can be formed (hereinafter referred to as an image forming position). Further, the opening / closing door 3 can be in a position where the process cartridge P can be taken out (hereinafter referred to as a drawing position). The open / close door 3 rotates from the closed position to the open position around the support shaft 27 at the lower part of the open / close door. The open / close door 3 is provided with a handle portion 3a for a user to perform an open / close operation, and a door link 30 for positioning the cartridge tray 29 and the process cartridge P in conjunction with the operation of the open / close door. Yes. The door links 30 are provided at both ends in the longitudinal direction of the image forming apparatus, and a tray holding member 28 is connected to each.

  As shown in FIG. 12, the image forming apparatus 1 is provided with a pressing mechanism 70 that is a pressing unit. When the opening / closing door 3 is closed and the process cartridge P is in the image forming position, the pressing mechanism 70 is interlocked with the tray holding member 28 and presses the cleaning unit 8 to place the photosensitive drum 4 inside the image forming apparatus 1. Perform positioning. Further, the pressing mechanism 70 acts on the cleaning unit 7 to position the cleaning unit 7 at a predetermined position inside the image forming apparatus 1.

  As shown in FIG. 13, a main frame 71 that forms a skeleton of the image forming apparatus main body 1 is provided on the outside of each tray holding member 28 of the image forming apparatus main body 1 </ b> A. The main frame 71 includes a support portion 71a that defines the position of the cleaning unit 8 inside the image forming apparatus 1, a support portion 71b that defines the position of the cleaning unit 7 in the X direction, and a support portion that defines the position in the Y direction. 71c is provided. Mounting and positioning of the cartridge P and the cleaning unit 7 inside the image forming apparatus 1 are performed according to the following procedure.

  First, FIG. 11 shows a state where the open / close door 3 is in the open position and the cartridge tray 29 is in the drawer position. In this state, the cartridge P can be detached from the cartridge tray 29. When the cartridge P is mounted, the cartridge P is fitted into the cartridge tray 29 from above and temporarily mounted. The cartridge tray 29 engages with a rotation stop boss 55 and a groove 60 (see FIGS. 3 and 4) of the cartridge P, and an engagement portion that determines the posture of the cartridge P in the rotation direction inside the image forming apparatus 1. Is provided (not shown). As a result, the orientation of the cartridge P in the rotation direction within the image forming apparatus 1 is determined.

  Further, the cartridge P has provisional engaging portions with the cartridge tray 29 at both ends in the longitudinal direction (not shown), and this portion is engaged with the cartridge tray 29 so that the vertical position is provisionally determined. Is done.

  Next, FIG. 14 shows a state in which the cartridge P is led into the image forming apparatus 1 (hereinafter referred to as a mounted state). At this time, the cartridge tray 29 is pushed from the pulled-out state to a predetermined position inside the image forming apparatus 1, and the open / close door 3 is in an open state. At this time, the cartridge P is maintained in the state supported by the cartridge tray 29, and the image forming apparatus main body 1A is not positioned.

  Next, the open / close door 3 is rotated in the H direction toward the closed position, and the cartridge tray 29, the cartridge P, and the cleaning means 7 are positioned at the image forming position.

  This process is divided into a process of seating the cartridge tray 29 and the cartridge P at a predetermined position and a process of holding the cartridge and the cleaning means 7 at a predetermined position by the pressing mechanism 70.

  First, a process of seating the cartridge tray 29 and the cartridge P at predetermined positions will be described.

  When the opening / closing door 3 is rotated in the direction of arrow H in FIG. 14, the holding member 28 starts to move downward in the figure via the door link 30. Then, in conjunction with the movement of the holding member 28, the cartridge tray 29 and the cartridge P move downward. When the cartridge tray 29 moves by a predetermined amount (4 mm in the present embodiment), the cartridge tray 29 comes into contact with the photosensitive drum positioning portion 71a (see FIG. 13) of the main frame 71, and the cartridge P is brought to a predetermined position in the image forming apparatus. Sit down. Further, the open / close door 3 is rotated in the direction of arrow H in the figure. Then, the holding member 28 continues to descend through the link 30. Then, it engages with a positioning portion (not shown) for positioning the cartridge tray 29 provided in the image forming apparatus main body 1A in the vertical direction and the front-rear direction, and the position of the cartridge tray 29 in the image forming apparatus 1 is defined. Is done. By moving from the open / close door position to the closed position, the lowering amount by which the cartridge tray 29 is lowered is set to be larger than the lowering amount of the cartridge P described above (5 mm in this embodiment). When the cartridge P reaches the closing position of the opening / closing door 3, the cartridge tray 29 and the temporary engagement portion are separated from each other and are not affected by the temporary positioning. In other words, the position of the cartridge P is uniquely defined by the photosensitive drum positioning portion 71a of the image forming apparatus 1 in the vertical direction inside the image forming apparatus.

  Further, the position of the cartridge tray 29 is positioned in the image forming apparatus, whereby the posture of the cartridge P in the rotational direction is also defined. As a result, the cartridge P is completely seated at a predetermined position in the image forming apparatus.

  Next, the process of holding the seating position of the cartridge P by the pressing mechanism 70 and positioning and holding the cleaning means 7 will be described with reference to FIGS. 13, 15, and 16. FIG. Here, FIG. 15 is a partial sectional view showing the state of the cartridge P and the pressing mechanism 70 from the front side to the non-driving side of the image forming apparatus 1. FIG. 16 is a partial cross-sectional view of the cartridge P and the pressing mechanism 70 as seen from the non-driving side surface of the image forming apparatus 1.

  When the cartridge P is lowered together with the cartridge tray 29, positioning portions 7h provided on the cleaning means 7 provided on one end side and the other end side in the longitudinal direction of the cartridge P are positioned on the image forming apparatus main body 1A. Engagement with the part 71b is started. At this time, since the cleaning unit 7 is supported in the cartridge P with a backlash, the cleaning unit 7 is not accurately positioned for image formation.

  Thereafter, the pressing frame 75 which is a skeleton part of the pressing mechanism 70 starts to descend with a delay from the lowering of the cartridge tray 29. This timing is achieved by engaging the guide groove formed in the holding member 28 and the boss of the pressing frame 75 (not shown).

  The pressing mechanism 70 has the following configuration. The photosensitive member pressing member 74 is slidably held with respect to a blade holding member 76 described later, and presses the cleaning frame 33 of the cartridge P in the direction of arrow R in the drawing to hold the position of the photosensitive drum 4. The urging member 75 is a means for urging the photoreceptor pressing member 74. The first blade holding member 76 is slidably held with respect to the pressing frame 75, presses the cleaning means 7 in the -Y direction (in the direction of arrow S in the figure), and holds in the -Y direction. The urging member 77 is a member that urges the first blade holding member 76.

  When the open / close door 3 is closed, the photosensitive member pressing member 74 presses the cleaning frame 33 by the urging force of the urging member 75. The photosensitive drum 4 is already seated at a position where an image can be formed by the positioning portion 56L of the cover member 31 and the positioning portion 71a of the frame, and the seating position is held by pressing of the photosensitive member pressing portion 74.

  The second blade holding member 78 is held so as to be slidable in the X direction with respect to the first blade holding member 76, presses the second force receiving portion 7h, and holds the position of the cleaning means 7 in the X direction. . The urging member 79 is a member that urges the blade holding member 78.

  The frame 71 which is a part of the image forming apparatus main body 1A is provided with an X direction positioning portion 71b and a -Y direction positioning portion 71c. The cleaning means 7 is urged from the directions of arrows U and S in the drawing by the first blade holding member 76 and the second blade holding member 78, respectively, with respect to the positioning portions 71b and 71c. The biasing is performed by biasing members 77 and 79. The urging force of the urging members 75, 77 and 79 is set so as to resist the force corresponding to the component force in each direction with respect to the contact pressure between the photosensitive drum 4 and the cleaning means 7.

  As a result, the cleaning unit 7 is positioned at a predetermined position inside the image forming apparatus 1. In other words, the cleaning means 7 moves within the range of play provided in the cleaning unit 8, and the elastic blade 7b moves to a state where it enters a predetermined amount with respect to the photosensitive drum 4 (see FIG. 6). Pressure is generated. Therefore, the cleaning unit 7 can clean the surface of the photosensitive drum 4. At this time, each sealing member in the cleaning unit 8 has a predetermined compression rate to ensure sealing performance.

  As described above, when the open / close door 3 is closed from the open position to the closed position, the cartridge P and the cleaning means 7 are positioned at predetermined positions, and an image can be formed.

  The cartridge P can be removed from the image forming apparatus 1 by a procedure reverse to the above procedure. When the cartridge P is removed from the image forming apparatus 1, the entire cleaning unit 7 is moved by a backlash with the cleaning frame 33 due to the elastic force of the elastic blade 7 b of the cleaning unit.

  Note that the present embodiment is not limited to the form used for the description. A configuration in which a plurality of process cartridges are mounted on the main body of the image forming apparatus from the longitudinal direction of the photosensitive drum or a configuration in which a single color process cartridge is mounted on the main body of the image forming apparatus can be applied. Alternatively, a process cartridge in which only the cleaning unit can be attached to and detached from the image forming apparatus main body can be used.

  As described above, according to this embodiment, the cleaning unit is attached to the cleaning frame so as to be movable by a predetermined amount, and the position of the cleaning unit and the photosensitive drum is set when the process cartridge is mounted in the image forming apparatus. A relationship is defined. Thereby, it is possible to suppress the deterioration of the cleaning performance by suppressing the deformation of the blade of the cleaning means during transportation and storage.

  In addition, when the process cartridge is a single unit, the contact force of the cleaning unit blade against the photosensitive drum can be reduced.

  Conventionally, the contact force generated in the elastic blade directly acts on the cleaning frame that firmly supports the cleaning means. Accordingly, when the process cartridge alone is stored, if there is a sudden temperature change or the like, the positional deviation may occur due to the difference in the linear expansion coefficient between the cleaning frame and the cleaning means supporting sheet metal. However, this is not the case with the present embodiment.

  Further, since the load on the cleaning frame body by the cleaning means is almost eliminated, it is possible to prevent creep deformation of the cleaning frame body during storage. Conventionally, the cleaning frame supports the contact pressure load of the cleaning means during the period from the manufacture of the process cartridge to the end of use by the user. Has been set up. However, in the present embodiment, such a load does not occur, so that the cleaning frame can be made thinner and smaller, and there is no need to reinforce the load of the cleaning means.

  Further, when mounted in the image forming apparatus, the positional relationship between the photosensitive drum and the cleaning unit is defined by the main frame of the image forming apparatus formed of a steel plate having high strength and low linear expansion coefficient. For this reason, the positional relationship between the photosensitive drum and the cleaning unit can be stably obtained even with respect to the temperature change in the apparatus depending on the usage state of the image forming apparatus, and the cleaning performance is stabilized.

1 image forming apparatus,
DESCRIPTION OF SYMBOLS 1A Image forming apparatus main body 3 Apparatus opening / closing door 4 Photosensitive drum 5 Charging roller 6 Developing roller 7 Cleaning means 8 Cleaning unit 9 Developing unit 27, 28 Holding member 29 Cartridge tray 31 Driving side cover member 32 Non-driving side cover member 33 Cleaning frame Body 34 Developing container 63 Longitudinal seal member 64 End seal member 65 Auxiliary seal member 66 Seat surface seal member 70 Press mechanism 74 Press member P (PY, PM, PC, PK) First to fourth process cartridges

Claims (7)

A process cartridge that can be attached to and detached from an electrophotographic image forming apparatus,
(A) an electrophotographic photosensitive drum;
(B) a frame;
(C) cleaning means for removing developer from the electrophotographic photosensitive drum,
A blade that contacts the electrophotographic photosensitive drum that is elastically deformable;
A support member for supporting the blade, wherein the blade is supported on the frame body so as to be movable in an entering direction for allowing the blade to enter the electrophotographic photosensitive drum and a retracting direction for retracting the blade, and the process When the cartridge is mounted on the main body of the electrophotographic image forming apparatus, the force that receives the force in the approach direction for pressing the blade against the electrophotographic photosensitive drum from the pressing member provided on the main body of the apparatus A support member having a receiving part, and a cleaning means having
The process cartridge according to claim 1, wherein the force receiving portion is provided on one end side and the other end side in the longitudinal direction of the support member .   2. The process cartridge according to claim 1, wherein the frame is provided with a restricting portion that contacts the support member and restricts the cleaning unit from moving a predetermined amount or more in the entering direction. .   When the process cartridge is mounted on the apparatus main body, the support member presses a force in a direction intersecting the entry direction for pressing the support member against an attachment portion provided on the frame body. The process cartridge according to claim 1, further comprising a second force receiving portion received from the member. In an electrophotographic image forming apparatus for forming an image on a recording medium, in which a process cartridge is detachable,
(A) a pressing member movably provided;
(B) an electrophotographic photosensitive drum, a frame, a cleaning unit that removes the developer from the electrophotographic photosensitive drum, a blade that contacts the elastically deformable electrophotographic photosensitive drum, and the blade A support member for supporting the frame so that the blade can move in an approach direction for allowing the blade to enter the electrophotographic photosensitive drum and a retract direction for retracting the blade, and the process cartridge includes: A force receiving portion that receives a force in the entering direction for pressing the blade against the electrophotographic photosensitive drum from a pressing member provided on the apparatus main body when the apparatus is mounted on the apparatus main body of the electrophotographic image forming apparatus. A mounting member for removably mounting the process cartridge;
(C) conveying means for conveying the recording medium;
(D) an open / close door that takes an opening for mounting the process cartridge on the mounting means, a closed position for closing the opening, and an open position for opening the opening;
The electrophotographic image forming apparatus , wherein the pressing member applies a force to the force receiving portion in conjunction with the opening / closing door moving from the open position to the closed position . In an electrophotographic image forming apparatus for forming an image on a recording medium, in which a process cartridge is detachable,
(A) a pressing member movably provided;
(B) an electrophotographic photosensitive drum, a frame, a cleaning unit that removes the developer from the electrophotographic photosensitive drum, a blade that contacts the elastically deformable electrophotographic photosensitive drum, and the blade A support member for supporting the frame so that the blade can move in an approach direction for allowing the blade to enter the electrophotographic photosensitive drum and a retract direction for retracting the blade, and the process cartridge includes: A force receiving portion that receives a force in the entering direction for pressing the blade against the electrophotographic photosensitive drum from a pressing member provided on the apparatus main body when the apparatus is mounted on the apparatus main body of the electrophotographic image forming apparatus. A mounting member for removably mounting the process cartridge;
(C) conveying means for conveying the recording medium ,
When the process cartridge is mounted on the apparatus main body, the pressing member is pressed by the second force receiving portion provided on the support member by the attachment portion provided on the frame body. An electrophotographic image forming apparatus for applying a force in a direction intersecting with the approach direction .   Furthermore, the electrophotographic image forming apparatus has an opening for mounting the process cartridge on the mounting means, a closed position for closing the opening, and an open / close door for opening the opening. 6. The electrophotographic image forming apparatus according to claim 5, wherein the pressing member applies force to the force receiving portion in conjunction with the opening / closing door moving from the open position to the closed position. When the process cartridge is mounted on the apparatus main body, the pressing member is pressed by the second force receiving portion provided on the support member by the attachment portion provided on the frame body. The electrophotographic image forming apparatus according to claim 4 , wherein a force in a direction intersecting with the approaching direction is applied.

Images