JP4638247B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to a process cartridge and an image forming apparatus used in an image forming apparatus such as a copying machine, a facsimile machine, and a printer.

  2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus is known in which an electrostatic latent image formed on an image carrier is developed using a developer and transferred onto a recording body to form an image. There is also known a process cartridge in which at least one of a charger, a developing device, a transfer device, and a cleaning device arranged around an image carrier such as a photoconductor drum and an image carrier are housed in a housing that can be attached to and detached from the apparatus main body. ing. This process cartridge is intended to reduce the burden of maintenance and the like by replacing the entire process cartridge when the photosensitive member and the like inside it have reached the end of its life.

  As a mechanism for positioning the image carrier in the process cartridge at a fixed position in the apparatus with the process cartridge set in the image forming apparatus main body, one end side of the image carrier is positioned on the process cartridge, and the other end side. There is also known a mechanism that is positioned at a fixed position in the apparatus main body by a member (for example, a shaft member) on the apparatus main body side for the first time after being mounted on the apparatus main body.

  However, the process cartridge employs a positioning mechanism for the image carrier, and includes a cleaning member (cleaning blade, etc.) for removing residual toner and the like remaining on the image carrier after the transfer is completed. It has been found that the following problems occur in a unit having a function of transporting a residue such as toner (unit of a waste toner transport coil). That is, in such a process cartridge, there is a problem that toner leaks when the process cartridge is carried alone. The toner leaks mainly at the toner outlet of the unit and between the image carrier and the cleaning member. Of these, it has been found that toner leaks from between the image carrier and the cleaning blade as follows. As described above, the end of the image carrier that is positioned at a fixed position in the apparatus main body for the first time after being mounted on the apparatus main body is in a state where there is play when the process cartridge is in a single state. It is only held in the receiving part of the cartridge. For this reason, a gap is formed between the cleaning member and the surface of the image carrier on the end side, and toner leaks from the gap.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the object of the present invention is to provide a part for fixing the positions of both ends of the image carrier, one on the process cartridge itself, and the other on the image forming apparatus main body. A process cartridge for an image forming apparatus, the position of which is fixed when mounted on the printer, and in which the process cartridge alone does not cause toner leakage.

In order to achieve the above object, the invention of claim 1 is an electrophotographic system in which an electrostatic latent image formed on an image carrier is developed with a developer and transferred onto a recording medium to form an image. And at least an image carrier, a cleaning member for removing transfer residual toner and the like remaining on the image carrier after completion of transfer, transfer residual toner, etc. In a process cartridge equipped with a unit having a functional member for transporting the residual material, one part is located in the process cartridge and the other is attached to the image forming apparatus main body. The position of the image carrier is fixed when the image carrier is not attached to the image forming apparatus main body, and the position of the image carrier can be fixed equivalent to the state of being attached to the apparatus main body. Toner residue In which it characterized in that a cap having a function of covering so that the toner does not leak from the discharge port for discharging the objects from the unit.
According to a second aspect of the present invention, in the process cartridge according to the first aspect, the cap also has a portion that covers an externally exposed portion of a terminal for applying a voltage or grounding.

  According to the first and second aspects of the present invention, the end of the image carrier whose position is fixed when mounted on the image forming apparatus main body is not mounted on the image forming apparatus main body. It can be fixed with a cap equivalent to the state of being attached to. Therefore, there is no gap between the cleaning member and the image carrier surface on the end side, and toner leakage from such a gap can be prevented. Further, since the discharge port of the unit for transporting the residue is also closed with a cap, toner leakage from the discharge port can be prevented.

An embodiment in which the present invention is applied to a process cartridge of a copying machine which is an electrophotographic image forming apparatus will be described.
FIG. 2 is a schematic configuration diagram of the process cartridge 1 according to the present embodiment, and FIG. FIG. 4 is a longitudinal sectional view taken along the axis of the photosensitive member (image carrier) 3.
In FIG. 2, 3 is a photosensitive drum as an image carrier, 4 is a charging roller as a charger, 5 is a charging cleaning roller, 6 is a fur brush roller, 7 is flicker, 8 is a lubricant block, and 9 is a lubricant. A block pressing spring, 10 a waste toner conveying coil, 11 a cleaning blade as a cleaning member, 12 a cleaning blade holder, and 13 a cleaning pressurizing spring. Reference numeral 2 denotes a rear side end wall which becomes the back side of the apparatus when set in the apparatus main body of the process cartridge, and hatching is provided, and a wall part is a peripheral wall of the process cartridge 1. Reference numeral 14 denotes a non-guide portion guided by a guide rail on the main body side when the process cartridge 1 is set in the copying machine main body, and reference numeral 18 denotes a positioning pin for the copying machine main body. Similarly, positioning pins are provided on the front end wall of the process cartridge 1 (not shown).
The charging roller 4 is pressed against the photosensitive drum 1 using a spring (not shown). The charging roller 4, the fur brush roller 6 and the waste toner coil 10 are driven to rotate by being transmitted from a gear or the like (not shown) on the photosensitive drum shaft. The charging cleaning roller 5 rotates following the charging roller surface. In the drawing, the rotation direction of the photosensitive drum 3 and the charging cleaning roller 5 is clockwise, and the charging roller 4 and the fur brush roller 6 are counterclockwise.
In FIG. 1, the phantom lines indicate main mechanisms on the copying machine main body side, 15 is a developing device, 16 is a paper transport belt, and 17 is a transfer roller as a transfer device.

  In FIG. 3, reference numeral 20 denotes a cover that covers the front side end of the waste toner carrying coil protruding from the front side end wall, and reference numeral 21 denotes a waste toner discharge port formed in the cover. 22 is a terminal made of a sheet metal for applying a voltage to the charging roller 2, 23 is a terminal made of a sheet metal for grounding the shaft of the fur brush roller, and 24 is an outer side from the front end wall of the photosensitive drum described later. The flange portion 25 projecting to the bottom is a receiving portion of the process cartridge 1 that receives the flange portion. In FIG. 3, the guided portion 14 is not shown.

  In FIG. 4, the end walls 30 and 31 are fixed to both ends of a hollow cylindrical photosensitive drum whose both ends are open. The photosensitive member front side end wall member 30 that faces the process cartridge front side end wall 32 that is on the front side of the apparatus when set in the copying machine main body has a shaft portion 33 that protrudes outward from the center portion. The shaft portion 33 is rotatably received by a bearing (for example, a bearing) 34 provided on the front end wall 33 of the process cartridge. On the opposite side of the photoconductor back side end wall member 31, a through hole 35 is formed at the center portion, and a flange portion 36 protruding outward from the vicinity of the peripheral portion is formed. A receiving portion 37 is formed on the front end wall 2 of the process cartridge so as to cover the periphery of the flange portion 36. The inner diameter of the receiving portion 37 is set to be about 5 mm larger than the outer shape of the flange portion 36. The photoconductor drive shaft 40 of the copying machine main body indicated by a virtual line (two-dot chain line) in the drawing enters the through hole 35 of the front end wall member 31 of the photoconductor, and thereby the back side of the photoconductor drum 1. The end is positioned at a fixed position in the copier body. Similarly, the receiving portion 37 of the end wall 2 on the back side of the process cartridge is held by a holder 41 on the copying machine main body side indicated by a virtual line. The drive shaft 40 is also provided with a drive transmission coupling 42, which is formed on the inner peripheral surface of the flange portion 36 of the photoconductive drum 3 or the outer surface of the rear end wall portion 31 of the photoconductive drum. Engage with the part to transmit drive.

  FIG. 5 is an explanatory diagram of a mechanism for receiving and storing the residual toner conveyed by the waste toner coil 10 of the process cartridge 1. The toner is accommodated in a waste toner container 51 through a pipe 50 that is conveyed by the waste toner coil 10 and dropped from the discharge port 21 of the cover 20. In the illustrated example, a screw 52 that imparts a conveying force to a part of the pipe 50 is also provided.

  In the above structure, the process cartridge 1 is set in the copying machine main body prior to shipment from the factory, and performs the cleaning operation while operating the developing device 15 (see FIG. 2). By this operation, the lubricant is applied to the peripheral surface of the photosensitive drum 3 and the toner is supplied to the contact portion between the cleaning blade 11 and the photosensitive drum 3. This is a process for preventing chattering between the cleaning 11 and the photosensitive drum 3 at the stage of delivery to the customer. After performing this processing, the product is packed in a transport cover or the like and shipped as a new process cartridge 1. Therefore, from the time of shipment, the toner is accommodated in the cleaning unit in the housing of the process cartridge 1. Moreover, in the process cartridge 1 of the present embodiment, the discharge port 21 is formed in the cover 21 (see FIG. 3) that covers the front end of the waste toner coil 10 as described above. Further, since there is play between the outer periphery of the flange portion 36 at the front end portion of the photosensitive drum 1 and the inner periphery of the receiving portion 37 of the process cartridge, a cleaning blade is provided at the front end portion of the photosensitive drum 1. 11 is separated from the surface of the photoconductor to form a gap. Therefore, the toner may leak from the discharge port 21 or the gap. Therefore, in the present embodiment, a configuration for preventing these toner leaks is employed.

  FIG. 1 is a perspective view of the process cartridge 1 with the cap 60 having the above-described configuration attached, viewed from the rear end side, FIG. 6A is a perspective view of the cap 60, and FIG. 3 is a cross-sectional view of the cap 60. FIG.

  In FIG. 6A, the cap 60 enters the receiving portion 37 of the process cartridge 1 and the flange portion 36 of the photosensitive drum 3, and further enters the through hole 35 of the photosensitive member rear side end surface member 31. Also, a cap portion 61 that also enters and a discharge port cover portion 62 that covers the cover 20 of the waste toner coil 10 are provided. Further, cover portions 63 and 64 are provided to cover the bias application terminal 22 and the grounding terminal 23 exposed to the outside of the back end wall 2 of the process cartridge 1, respectively.

  In FIG. 6B, the cap portion 61 is further fitted to the inner peripheral surface of the receiving portion 37 of the front end wall 2 of the process cartridge and to be fitted to the inner peripheral surface of the flange portion 36. 61a, 61b, and a fitting portion 61c that fits into the through hole 35. The cap is fixed to the process cartridge 1 by the fitting portions 61a and 61b and the fitting portion 61c, and the process cartridge 1 is not attached to the copying machine main body and is equivalent to the state attached to the copying machine main body. The position of the back end of the photosensitive drum 3 is fixed with respect to the process cartridge 1. Either one of the fitting portion 61b with respect to the flange portion 36 and the fitting portion 61c with respect to the through hole 36 may simply enter without fitting. Even in this case, the fixing can be performed by the other.

  In FIG. 1, when the cap 60 is fitted, the back end of the photosensitive drum 3 is fixed at a fixed position in the process cartridge 1, and the front end is fixed at a fixed position in the process cartridge 1 as described above. Therefore, the cleaning blade 11 and the surface of the photosensitive drum 3 are in uniform contact with each other in the width direction. As a result, there is no gap between the two and toner leakage does not occur. Further, since the discharge port 21 of the cover 20 of the waste toner coil 10 is covered by the cover portion 62 of the cap 60, toner leakage from the discharge port 21 can be prevented. Furthermore, since both the terminals 22 and 23 are covered with the cover parts 63 and 64 of the cap 60, it is possible to prevent the user from touching the terminal part and getting injured. In FIG. 1, the guided portion 14 is not shown.

  As the color of the cap 60, it is desirable to adopt a color that calls attention (for example, yellow or orange). According to this, it is possible to suppress forgetting to remove the cap 60 before the process cartridge 1 is attached to the copying machine main body. Further, the tag 65 may be integrally formed with the cap 60 as indicated by a virtual line (two-dotted line) in FIG. According to this, it is possible to reduce the cost as compared with a case where a tag is separately attached. It is desirable to reuse such a cap 60 to reduce the cost and reduce the influence on the environment.

  With the cap 60 as described above attached, the process cartridge 1 is shipped as a replacement process cartridge 1 or as a process cartridge 1 that is packaged separately from the inside of the copying machine main body.

As described above, according to the image forming apparatus of the present embodiment, by providing the cover 60 covering the discharge port 21 with the cap 60, it is possible to prevent problems due to toner leakage during packing, transportation, and unit replacement. Further, by providing the portion 61 for fixing the photosensitive drum 3, the pressure of the cleaning blade 11 and the photosensitive drum 3 can be made constant, the deformation of the blade 11, and the toner leakage from between the blade 11 and the photosensitive drum 3. In addition, problems such as blade deformation due to long-term storage can be prevented.
Further, since the caps 60 are also provided with the portions 63 and 64 that cover the exposed portions 22 and 23 of the contact made of a sheet metal for charging or grounding, the user and the serviceman do not touch the sheet metal directly. Injuries to users and service personnel can be prevented.
If the cap 60 is left at the customer site or brought by a service person for maintenance, the cap 60 is attached even when the process cartridge 1 in use is temporarily removed from the copying machine main body. It is also possible to prevent toner leakage after removal.

The perspective view of the state which attached the cap of the process cartridge which concerns on embodiment. FIG. 2 is a schematic configuration diagram of the cartridge. The perspective view of the state which removed the cap of the cartridge. Sectional drawing of the cartridge. Explanatory drawing of the waste toner collection mechanism of the cartridge. (A) is a perspective view of a cap, (b) is sectional drawing of a cap.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Side wall 3 Each photoconductor drum 11 Cleaning blade 20 Waste toner coil cover 21 Ejection port 22 Terminal 23 Terminal 60 Cap 61 Cap part 62 Cover part 63 Cover part 64 Cover part

Claims (2)

The electrostatic latent image formed on the image carrier is developed using a developer, transferred onto a recording medium, and is detachable from an electrophotographic image forming apparatus that forms an image. And an image carrier, a cleaning member for removing residues such as transfer residual toner remaining on the image carrier after completion of transfer, and a functional cartridge for transporting residues such as transfer residual toner In
The part that fixes the positions of both ends of the image carrier is in the process cartridge, and the other is configured to be fixed in position when mounted on the image forming apparatus main body.
The toner from the discharge port that can fix the position of the image carrier in the state that is not attached to the main body of the image forming apparatus and is equivalent to the state that is attached to the main body of the image forming apparatus, A process cartridge comprising a cap having a function of covering so as not to leak. The process cartridge according to claim 1.
A process cartridge, wherein the cap also has a portion that covers an externally exposed portion of a terminal for applying voltage or grounding.

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