JP2006017813A - Process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process cartridge obtaining a good image by efficiently cooling peripherals of a developing roller and peripheral of an electrifying member even when the temperature inside the apparatus is raised due to downsizing of the apparatus or due to increasing of printing speed by efficiently cooling the bearing of a photorecepter drum by reducing windage in a ventilation opening communicating with a cooling fan and a ventilation opening part of a process cartridge and efficiently cooling a bearing part of a photoreceptor drum. <P>SOLUTION: The process cartridge includes a first ventilation opening on one side surface of a drum frame body and a second ventilation opening on the other side. The second ventilation opening is formed in a direction which is approximately in parallel with the loading direction of the process cartridge to an electrophotographic image forming apparatus main body. When the process cartridge is loaded to an image forming position of the electrophotographic image forming apparatus main body, the ventilation opening on the electrophotographic image forming apparatus main body side and the second ventilation opening are overlapped in the direction loading the process cartridge to the electrophotographic image forming apparatus main body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a process cartridge used for image formation such as a printer or a copying machine.

  2. Description of the Related Art Conventionally, in an electrophotographic 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 printer is detachably attached to the main body of the electrophotographic image forming apparatus. In such a process cartridge system, the photosensitive drum and at least one of the charging unit, the developing unit, and the cleaning unit or at least the developing unit are integrally formed into a cartridge, and this cartridge is used as the main body of the electrophotographic image forming apparatus. On the other hand, there are things that can be detached.

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

  In this type of process cartridge, the photosensitive drum unit in which the photosensitive drum and the cleaning unit are integrally formed, and the developing device unit in which the developing sleeve, the toner storage container, and the like are united are combined and integrated. A cartridge is known. In this process cartridge, the photosensitive unit is configured by attaching a photosensitive drum, a charging unit, and a cleaning unit to the drum frame, and the developing device unit further includes a developing blade in addition to the developing sleeve and the toner storage container. And a toner conveying means. In such an image forming apparatus, if the temperature inside the apparatus rises remarkably, the developer may deteriorate and good development may not be obtained. In order to prevent this, a cooling fan is provided in the main body of the image forming apparatus to suppress the temperature rise inside the apparatus (for example, see Patent Document 1).

  In addition, when the process cartridge is mounted on the image forming apparatus, the ventilation hole provided in the process cartridge and the ventilation hole provided in the image forming apparatus main body are opposed to each other so that air can be efficiently flowed and cooled inside the process cartridge. Is known (see, for example, Patent Document 2).

JP-A-11-218987 (page 6, FIG. 1) JP-A-11-305634 (page 10, FIG. 7)

  As shown in FIG. 17, it is known that the air vent 100 provided in the process cartridge B and the air vent 101 communicating with the cooling fan F of the image forming apparatus main body A are opposed to each other. There is a gap L1 between the image forming apparatus main body A and the process cartridge B, and the dimensional relationship is such that the process cartridge B does not stretch in the image forming apparatus main body A. Between the vent 100 of the process cartridge B and the vent 101 of the image forming apparatus main body A, there is a gap L2 that is larger than the gap L1 between the image forming apparatus main body A and the process cartridge B. For this reason, the windage loss of the cooling fan F may become large depending on variations such as dimensional tolerances. The arrows in FIG. 17 indicate the flow of wind.

  Further, when the apparatus is downsized and the printing speed is increased, the temperature inside the image forming apparatus is likely to increase, and even inside the process cartridge B, the friction between the developing roller and the developing blade, the friction between the photosensitive drum and the cleaning blade, Further, the amount of heat generated by the sliding of the bearing portion of the photosensitive drum may increase, and the temperature inside the process cartridge B may easily rise.

  Accordingly, the present invention is a further development of the conventional example, and reduces windage loss at the vent hole communicating with the cooling fan of the image forming apparatus main body and the vent hole portion of the process cartridge, and the bearing portion of the photosensitive drum. By effectively cooling the device, even if the device is downsized or the printing speed increases and the temperature inside the device rises, the periphery of the developing roller and the charging member inside the process cartridge is effectively cooled, It is an object of the present invention to provide a process cartridge capable of obtaining a good image.

To achieve the above object, the present invention provides a process cartridge that can be attached to and detached from an electrophotographic image forming apparatus main body,
An electrophotographic photosensitive drum;
A drum frame for supporting the electrophotographic photosensitive drum;
A charging member for charging the electrophotographic photosensitive drum;
A developing device having a developing roller for developing the electrostatic latent image formed on the electrophotographic photosensitive drum using a developer;
A first vent provided on one side of the drum frame;
A second vent on the other side of the drum frame;
The second vent is formed in a direction substantially parallel to a direction in which the process cartridge is mounted on the electrophotographic image forming apparatus main body.
When the process cartridge is mounted at the image forming position of the electrophotographic image forming apparatus main body, the vent hole on the electrophotographic image forming apparatus main body side and the second vent hole attach the process cartridge to the electrophotographic image forming apparatus main body. It overlaps in the direction to do.

  According to the process cartridge of the present invention, the vent hole communicating with the cooling fan of the main body of the image forming apparatus and the vent hole of the process cartridge can be connected with high accuracy, and the windage loss of the cooling fan can be reduced. Further, the bearing portion of the photosensitive drum can be efficiently cooled.

  Therefore, even if the device is downsized or the printing speed increases and the temperature inside the device rises, without increasing the diameter of the cooling fan or adding a cooling fan, the periphery of the developing roller and the charging roller around the process cartridge Thus, it is possible to provide a process cartridge capable of effectively cooling and obtaining a good image.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
[Description of Entire Image Forming Apparatus]
First, an image forming apparatus to which a process cartridge constructed according to the present invention is detachably mounted will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram showing a configuration of an electrophotographic image forming apparatus A according to the present invention, and FIG. 2 is a cross-sectional view of a process cartridge B that can be attached to and detached from the electrophotographic image forming apparatus according to the present invention. Here, the image forming apparatus is an apparatus that forms an image on a recording medium such as recording paper, an OHP sheet, and cloth using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (for example, , LED printer, laser beam printer, etc.), electrophotographic facsimile apparatus, electrophotographic word processor, and the like. In this embodiment, an electrophotographic laser beam printer will be described as an example.

  An image forming apparatus (laser beam printer in this embodiment) A has a drum-shaped electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) 7, and the photosensitive drum 7 is a charging member 8 (charging means). Hereinafter, the photosensitive drum 7 is charged with image data by irradiating a laser beam corresponding to the image information from the optical means 1 having a laser diode, a polygon mirror, a lens, and a reflection mirror. A corresponding latent image is formed. This latent image is developed by a developing device using a developer (hereinafter referred to as toner) to form a visible image, that is, a toner image.

  On the other hand, in synchronization with the formation of the toner image, the recording medium 2 set in the paper feed cassette 3a is conveyed to the transfer position by the pickup roller 3b and the conveying roller pairs 3c, 3d, and 3e. A transfer roller 4 as a transfer unit is disposed at the transfer position, and a toner image on the photosensitive drum 7 is transferred to the recording medium 2 by applying a voltage.

  The recording medium 2 that has received the transfer of the toner image is conveyed to the fixing unit 5 through the conveyance guide 3f. The fixing unit 5 includes a driving roller 5c and a fixing roller 5b incorporating a heater 5a, and fixes the transferred toner image on the recording medium 2 by applying heat and pressure to the passing recording medium 2. Thereafter, the recording medium 2 is conveyed by the discharge roller pairs 3g and 3h, and discharged to the discharge tray 6 via the reverse path 3i. The discharge tray 6 is provided on the upper surface of the image forming apparatus A. The swingable flapper 3j can be operated to eject the recording medium 2 without going through the reversing path 3i. The pickup roller 3b, the conveyance roller pairs 3c, 3d, 3e, the conveyance guide 3f, the discharge roller pairs 3g, 3h, and the like constitute the conveyance means 3 for the recording medium 2.

  The process cartridge B rotates the photosensitive drum 7 and uniformly charges the surface thereof by applying a voltage to the charging roller 8 serving as charging means. Next, a latent image is formed by irradiating the photosensitive drum 7 with laser light corresponding to image information from the optical means 1. The latent image is developed by developing means using toner.

  More specifically, the charging roller 8 is provided in contact with the photosensitive drum 7 and charges the photosensitive drum 7. The charging roller 8 is driven to rotate by the photosensitive drum 7. The developing unit supplies toner to the developing area of the photosensitive drum 7 to develop the latent image formed on the photosensitive drum 7.

  The developing means sends toner in a developer storage container (hereinafter referred to as a toner storage container) 14 to the developing chamber 13 a by the rotation of the stirring member 55. Then, the developing roller 10 incorporating the magnet roller (fixed magnet) 11 is rotated, and a toner layer to which frictional charge is applied by the developing blade 12 is formed on the surface of the developing roller 10. Then, the toner is transferred to the photosensitive drum 7 in accordance with the latent image, thereby forming a toner image and making it a visible image.

  The developing blade 12 defines the amount of toner on the peripheral surface of the developing roller 10 and applies a triboelectric charge.

  After the toner image is transferred to the recording medium 2 by the transfer roller 4, the photosensitive drum 7 is subjected to the next image forming process after the toner remaining on the photosensitive drum 7 is removed by the cleaning unit 17. The cleaning means 17 scrapes off the residual toner on the photosensitive drum 7 by an elastic cleaning blade 17a provided in contact with the photosensitive drum 7, and collects it in a waste toner reservoir 17b.

As shown in FIG. 3, the process cartridge B is detachably mounted on a cartridge mounting means provided on the image forming apparatus main body A by opening the cartridge door 9 of the image forming apparatus main body A. As shown in FIGS. 4 and 5, the cartridge mounting means of the present embodiment includes guide portions 30L1, 30L2, 30R1, and 30R2 formed on the image forming apparatus main body. When the process cartridge B is mounted on the image forming apparatus main body A, the cylindrical portions 40R1, 40R2, 40L1, and 40L2 (FIGS. 6 and 7) on both outer side surfaces of the process cartridge B are respectively replaced with the guide portions 30R1 of the image forming apparatus main body. , 30R2, 30L1, and 30L2.
[Configuration of process cartridge frame]
Next, the structure of the frame of the process cartridge B according to the present invention will be described.

  As shown in FIG. 2, the cleaning means 17 such as the photosensitive drum 7, the charging roller 8, and the elastic cleaning blade 17 a is attached to the drum frame 18 and constitutes an integral photosensitive unit 20.

  On the other hand, the developing device unit 19 includes a toner storage container 14 that stores toner, and a developing frame 13 that holds the developing roller 10 and the developing blade 12. The toner storage container 14 and the developing device frame 13 are integrally joined together by means such as welding of outer peripheral flange portions 14b and 13b.

Then, the process cartridge B is configured by rotatably coupling the photosensitive unit 20 and the developing device unit 19 to each other by a round pin coupling member 31. That is, as shown in FIG. 8, the end of the arm portions 13b, 13c formed on both sides in the longitudinal direction of the developing device frame 13 (axial direction of the developing roller 10) has a round rotation hole 13d parallel to the developing roller 10. , 13e are provided. Concave portions 18a and 18b for allowing the arm portions 13b and 13c to enter are provided at two locations on both sides of the drum frame 18 in the longitudinal direction. The arm portions 13b and 13c are inserted into the recesses 18a and 18b, the coupling member 31 is inserted into the mounting holes 18c and 18d of the drum frame 18, and is fitted into the rotation holes 13d and 13e of the arm portions 13b and 13c. In addition, the photoreceptor unit 20 and the developing device unit 19 are rotatably coupled around the coupling member 31 by being press-fitted into a hole (not shown) inside the drum frame. At this time, the compression coil springs 21 and 22 attached to the bases of the arm portions 13b and 13c hit the upper walls of the recesses 18a and 18b of the drum frame 18 to urge the developing device unit 19 downward, thereby developing the developing roller. 10 is firmly pressed against the photosensitive drum 7.
[Process cartridge drive structure and photosensitive drum support structure]
When the process cartridge B is mounted on the image forming apparatus main body A, a torsionally concave drive transmission member 80 (see FIG. 5) for transmitting drive from the drive source provided in the image forming apparatus main body A to the process cartridge; A triangular coupling 81a, which is a protrusion formed at the tip of a drum gear 81 attached to one end of the photosensitive drum 7 in the longitudinal direction, is fitted, and the drive is transmitted (see FIG. 9). The driving force transmitted to the triangular coupling 81a is engaged with an idler gear (not shown) via a developing roller gear (not shown) disposed at one end in the longitudinal direction of the developing roller 10 that meshes with the helical gear 81b of the drum gear 81. ) And the drive is transmitted to the developer stirring member 55 (see FIGS. 1 and 2).

The drive transmission side of the photosensitive drum 7 is attached to the drum frame 18 by a drum bearing member 82 shown in FIG. The drum bearing member 82 has a cylindrical portion 40R1 that comes into contact with a guide portion 30R1 formed in the image forming apparatus main body A. The cylindrical portion 82a of the drum bearing member 82 is fitted to and supported by a bearing portion 81c between the triangular coupling 81a of the drum gear 81 and the helical gear 81b. The drum bearing member 82 is fixed to the drum frame 18 by screws 82b. The counter drive side pivotally supports the photosensitive drum 7 by press-fitting a drum centering shaft 83 (see FIG. 7) into a through hole (not shown) of the drum frame 18. As a result, the photosensitive drum 7 is rotatably attached to the drum frame 18.
[Process cartridge air path configuration]
Next, the air path configuration of the process cartridge B in the image forming apparatus A according to the present invention will be described with reference to FIG. FIG. 10 is a diagram schematically showing the air path according to the present embodiment.

  The image forming apparatus main body A according to the present embodiment has a cooling fan F on the side having the drive transmission means, and discharges air to the outside of the image forming apparatus main body A (direction of arrow W5).

  On the non-driving side, the process cartridge passes through the louver 71a of the exterior 71 of the image forming apparatus main body A and the hole 70a of the side plate 70 of the image forming apparatus main body A, and passes through the first vent 60 of the drum frame 18 of the process cartridge B. Outside air is taken into B (wind direction of arrow W1). The taken-in outside air flows in the direction W2 while removing heat and moisture around the photosensitive drum 7 and the charging roller 8 and the developing roller 10 (not shown in FIG. 10). The air that has reached the drive side of the photosensitive drum 7 goes out of the process cartridge B from the second vent 61 provided in the drum frame 18 (wind direction of arrow W3).

  The air that has flowed out of the process cartridge B is guided to a duct member 72 from a later-described vent provided in the image forming apparatus main body A, and is discharged to the outside of the image forming apparatus main body A by the cooling fan F.

  This will be described in more detail with reference to FIGS.

  FIG. 11 is a perspective view for explaining the first ventilation port on the non-driving side of the drum frame 18, FIG. 12 is a perspective view for explaining the second ventilation port on the driving side of the drum frame 18, and FIG. FIG. 14 is a perspective view for explaining a vent hole and a duct provided in the image forming apparatus main body A, and FIG. 15 is a perspective view for explaining a state in which the process cartridge is attached to the image forming apparatus main body. FIG. 16 is a perspective view for explaining a state in which the process cartridge is mounted on the image forming apparatus main body.

  As shown in FIG. 11, a first vent 60 is provided on the non-driving side of the drum frame 18. As described above, outside air passes through the louver 71a of the exterior 71 of the image forming apparatus main body A and the hole 70a of the side plate 70 of the image forming apparatus main body A and is taken into the process cartridge B from the first vent 60. It is desirable that the first vent hole 60 be disposed at a position where the periphery of the charging roller 8 and the developing roller 10 can be efficiently cooled.

  As shown in FIGS. 9 and 12, a second vent 61 is provided on the drive side of the drum frame 18.

First, as shown in FIG. 9, the outside air taken in from the first vent 60 moves toward the second vent 61 while removing heat and moisture around the photosensitive drum 7, the charging roller 8, and the developing roller 10. Flowing. The second vent 61 is opened in a direction intersecting with the axis of the photosensitive drum 7. In the present embodiment, the hole direction of the second vent 61 is opened in a direction substantially perpendicular to the axis of the photosensitive drum 7. or,
As shown in FIG. 12, the second vent 61 includes a vent 61a communicating with a duct member 72 (see FIG. 14) provided in the image forming apparatus main body A, and a third vent shown in FIG. A ventilation hole 61 b communicating with 62 is provided.

  First, the vent 61b will be described.

  The vent 61 b communicates with a third vent 62 formed in the drum bearing member 82. As described above, the cylindrical portion 82a of the drum bearing member 82 is fitted to and supported by the bearing portion 81c of the drum gear 81, thereby generating frictional heat. In order to cool this, the air taken in from the notch portion 82c of the drum bearing member 82 flows while removing the heat around the cylindrical portion 82a, reaches the third vent 62, and vents the drum frame 18. The air is taken into the second vent 61 from the opening 61b (in the direction of the arrow W6). The third vent 62 is open in the state of FIG. 13, but is completed as an air passage by attaching the drum bearing member 82 to the drum frame 18.

  Next, the vent 61a will be described.

  As shown in FIGS. 14 to 16, the vent 61 a communicates with a vent 72 a (see FIG. 14) of a duct member 72 connected to a cooling fan F provided in the image forming apparatus main body A. As shown in FIG. 15, the vent 61 a is substantially parallel to the direction S in which the process cartridge B is mounted on the image forming apparatus main body A. Accordingly, as shown in FIG. 16, in the state where the process cartridge B is mounted on the image forming apparatus main body A, the vent 61 a can jump into the vent 72 a of the duct member 72.

  Further, a drive transmission member 80 (see FIG. 14) having a substantially twisted concave shape and a triangular coupling 81a which is a protrusion formed at the tip of the drum gear 81 are fitted from a drive source provided in the image forming apparatus main body A. The drive is transmitted. Then, a rotational moment is applied to the process cartridge B in the direction of arrow T in FIG. Then, the rotation stop portion 30R2a of the guide portion 30R2 and the cylindrical portion 40R2 of the process cartridge B abut, and the position of the process cartridge B in the image forming apparatus main body A is determined. Further, when the drive transmission member 80 and the triangular coupling 81a having a substantially twisted concave shape are fitted, the position of the process cartridge B in the image forming apparatus main body A in the longitudinal direction (perpendicular to the paper conveyance direction) is determined.

  As described above, since the position of the process cartridge B in the rotation direction and the longitudinal direction is determined with high accuracy, by providing the air vent 61a in the drum frame 18, the air vent 61a of the drum frame 18 and the duct member 72 are provided. The relative position of the vent 72a is also determined with high accuracy. Further, since the air vent 61a of the drum frame 18 and the air vent 72a of the duct member 72 overlap each other in the direction in which the process cartridge is mounted on the electrophotographic image forming apparatus main body, the windage loss of the cooling fan is kept small. Can do.

1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is sectional drawing of the process cartridge of embodiment of this invention. 1 is an external perspective view of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is an external perspective view showing a mounting portion of the apparatus main body for mounting the process cartridge of the present invention. FIG. 3 is an external perspective view showing a mounting portion of the apparatus main body for mounting the process cartridge of the present invention. 1 is an external perspective view of a process cartridge according to an embodiment of the present invention. 1 is an external perspective view of a process cartridge according to an embodiment of the present invention. 1 is an external perspective view illustrating a configuration of a process cartridge according to an embodiment of the present invention. It is a perspective view explaining the support structure of the photosensitive drum of embodiment of this invention. It is the figure which represented typically the air path of embodiment of this invention. It is a perspective view explaining the 1st vent on the non-driving side of an embodiment of the invention. It is a perspective view explaining the 2nd ventilation hole by the side of a drive of an embodiment of the invention. It is a perspective view explaining the 3rd vent of an embodiment of the invention. FIG. 3 is a perspective view illustrating a vent and a duct configuration provided in the image forming apparatus main body A according to the embodiment of the present invention. FIG. 4 is a perspective view for explaining a state in which the process cartridge is mounted on the image forming apparatus main body according to the embodiment of the present invention. FIG. 2 is a perspective view illustrating a state where a process cartridge is mounted on the image forming apparatus main body according to the embodiment of the present invention. It is a schematic diagram explaining the conventional example.

Explanation of symbols

A Image forming apparatus B Process cartridge F Cooling fan L1, L2 Gap S Process cartridge mounting direction T Process cartridge rotation direction W1 to W6 Air flow direction 1 Optical means 2 Recording medium 3 (3a, 3b...) Conveyance means DESCRIPTION OF SYMBOLS 4 Transfer roller 5 Fixing means 7 Photoconductor drum 8 Charging roller 9 Cartridge door 10 Developing roller 11 Magnet roller 12 Developing blade 13 Developing frame 13a Developing chamber 13b, 13c Arm part 13d, 13e Rotating hole 14 Toner container 14a Opening part 17 Cleaning means 17a Cleaning blade 17b Waste toner reservoir 18 Drum frame 18a, 18b Recessed part 18c, 18d Mounting hole 18d Groove 18e, 18f Abutting part 18g Rib 19 Developing unit 20 Photoconductor unit 30L1, L , R1, R2 guide part 30R2a rotation stop 40L1, L2, R1, R2 guide part 55 stirring member 60 first vent 61 second vent 61a vent 61b vent 62 third vent 70 side plate 70a side plate Hole 71 Exterior 71a Exterior hole 72 Duct member 72a Duct member vent 80 Drive transmission member 81 Drum gear 81a Triangular coupling 81b Lotus gear 81c Bearing portion 82 Drum bearing member 82a Cylindrical portion 82b Screw 82c Notch portion 83 Drum centering Shaft 100 Conventional vent 101 Conventional vent

Claims (4)

A process cartridge that can be attached to and detached from the electrophotographic image forming apparatus body,
An electrophotographic photosensitive drum;
A drum frame for supporting the electrophotographic photosensitive drum;
A charging member for charging the electrophotographic photosensitive drum;
A developing device having a developing roller for developing the electrostatic latent image formed on the electrophotographic photosensitive drum using a developer;
A first vent provided on one side of the drum frame;
A second vent on the other side of the drum frame;
The second vent is formed in a direction substantially parallel to a direction in which the process cartridge is mounted on the electrophotographic image forming apparatus main body.
When the process cartridge is mounted at the image forming position of the electrophotographic image forming apparatus main body, the vent hole on the electrophotographic image forming apparatus main body side and the second vent hole attach the process cartridge to the electrophotographic image forming apparatus main body. The process cartridge is characterized by overlapping in the direction of movement.   2. The process cartridge according to claim 1, wherein the axis of the electrophotographic photosensitive drum and the hole direction of the second vent hole intersect each other.   A second ventilation port portion is formed by a bearing member that pivotally supports a transmission portion that transmits driving from the driving means of the electrophotographic image forming apparatus main body to the electrophotographic photosensitive drum, and the drum frame. The process cartridge according to claim 1 or 2.   When the bearing member is assembled to the drum frame body, a space is formed between the bearing member and the drum frame body, and the second vent hole portion and the sliding portion vicinity of the bearing member communicate with each other. The process cartridge according to claim 1, further comprising three vent holes.

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