Patent Description:
The attachment is mountable to and dismountable from the main assembly of the image forming apparatus (electrophotographic image forming apparatus).

The dismountably mountable unit set is a combination (set) of units which can be mounted to and dismounted from the apparatus main assembly of the image forming apparatus.

An image forming apparatus (electrophotographic image forming apparatus) is an apparatus capable of forming an image on a recording material using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (LED printer, laser beam printer, and so on), a facsimile machine, a word processor, and so on are included.

In the electrophotographic image forming apparatus (hereinafter also simply referred to as "image forming apparatus"), an electrophotographic photosensitive member, which is generally a drum type as an image bearing member, that is, the photosensitive drum (electrophotographic photosensitive drum) is uniformly charged. Next, the electrostatic latent image (electrostatic image) is formed on the photosensitive drum by selectively exposing the charged photosensitive drum. Next, the electrostatic latent image formed on the photosensitive drum is developed into a toner image with toner as a developer. Then, the toner image formed on the photosensitive drum is transferred onto a recording material such as recording sheet or a plastic sheet, and heat or pressure is applied to the toner image transferred onto the recording material to fix the toner image on the recording material, thus effecting image recording operation.

Such an image forming apparatus generally requires toner replenishment and maintenance of various process means. In order to facilitate this toner replenishment and maintenance operations, a cartridge in which the photosensitive drum, charging means, developing means, cleaning means and so on are provided, and which is dismountable from the image forming apparatus main assembly, has been put into practical use.

According to this cartridge system, a part of the maintenance of the device can be performed by the user without relying on the service person in charge of the after-sales service. Therefore, the operability of the apparatus can be remarkably improved, and an image forming apparatus excellent in usability can be provided. Therefore, this cartridge system is widely used with the image forming apparatuses.

An example of the cartridge includes the cartridge. The process cartridge is a cartridge in which an electrophotographic photosensitive drum and process means which acts on the electrophotographic photosensitive drum are integrally formed into a cartridge, and the cartridge is dismountably mounted to the main assembly of the image forming apparatus.

In the above-described process cartridge, a structure in which a coupling member is provided at the free end of the photosensitive member drum to transmit the driving force from the apparatus main assembly to the photosensitive member drum is widely used. As described in <CIT>, the driving force is transmitted from the drive transmission member of the image forming apparatus main assembly to the coupling member of the process cartridge.

<CIT> teaches a mountable unit set according to the preamble of claim <NUM>.

<CIT> teaches an image forming apparatus includes an apparatus main-body and a process cartridge. A female connector is arranged on a developing roller shaft in the process cartridge. The female connector has an open-ended ring-like space formed between an outer ring and an inner ring. A plurality of track grooves are arranged on the circumference of at least one of the outer ring and the inner ring. One end of a cartridge driving shaft is supported in the apparatus main-body, while the other end thereof facing the process cartridge is movable in a radial direction. A male connector is arranged on the movable end of the cartridge driving shaft. A front portion of the male connector is a cylindrical spherical-body holding portion that rotatably holds a plurality of spherical bodies.

<CIT> teaches a removable bearing for mounting on a slot of a supporting wall is disclosed. The removable bearing includes a bearing member having a bore for receiving a rotatable shaft. The bearing also includes a handle fixedly attached to the bearing member. Attached to the handle is a latching member for engaging a corresponding aperture in the supporting wall when mounting the removable bearing thereon. The handle has an engagement portion that allows tool engagement for moving the handle away from the supporting wall to disengage the latching member when removing the bearing from the slot.

It is the object of the present invention to provide an improved further development of the above conventional structure considering the above discussed circumstances.

The above object is solved by a mountable unit set having the features of claim <NUM>.

Further developments are stated in the dependent claims.

An electrophotographic image forming apparatus comprising said mountable unit set is stated in claim <NUM>.

A cartridge mounting method with said mountable unit set is stated in claim <NUM>.

The conventional structure can be developed.

Hereinafter, Embodiment <NUM> will be described in detail with reference to the accompanying drawings.

Unless otherwise specified, the rotation axis direction of the electrophotographic photosensitive drum is simply referred to as the longitudinal direction.

Further, in the longitudinal direction, the side where an electrophotographic photosensitive drum receives the driving force from the image forming apparatus main assembly is a driving side, and the opposite side is a non-driving side.

Referring to <FIG> and <FIG>, the overall structure and image forming process will be described.

<FIG> is a cross-sectional view of an apparatus main assembly (electrophotographic image forming apparatus main assembly, image forming apparatus main assembly) A and a process cartridge (hereinafter, referred to as a cartridge B) of the electrophotographic image forming apparatus.

<FIG> is a sectional view of the cartridge B.

Here, the apparatus main assembly A is a portion of the electrophotographic image forming apparatus, excluding the cartridge B. The cartridge B is mountable to and dismountable from the apparatus main assembly A.

The electrophotographic image forming apparatus (image forming apparatus) shown in <FIG> is a laser beam printer using an electrophotographic technique in which the cartridge B is dismountably mounted to the apparatus main assembly A. When the cartridge B is mounted to the apparatus main assembly A, the exposure device <NUM> (laser scanner unit) for forming a latent image on an electrophotographic photosensitive drum <NUM> as an image bearing member of the cartridge B is provided. Is In addition, below the cartridge B, a sheet tray <NUM> accommodating recording materials to be subjected to the image forming operation (hereinafter referred to as sheet materials PA) is provided. The electrophotographic photosensitive drum <NUM> is a photosensitive member (electrophotographic photosensitive member) used for electrophotographic image formation.

In addition, in the main assembly A of the apparatus, along the conveyance direction D of the sheet material PA, there are provided a pickup roller 5a, a feeding roller pair 5b, a conveyance roller pair 5c, a transfer guide <NUM>, a transfer roller <NUM>, a conveyance guide <NUM>, a fixing device <NUM>, a discharge roller pair <NUM> and a discharge tray <NUM> in the order named. The fixing device <NUM> comprises a heating roller 9a and a pressure roller 9b.

Next, the outline of the image forming process will be described. In response to the print start signal, the electrophotographic photosensitive drum (hereinafter, referred to as photosensitive drum <NUM> or simply drum <NUM>) is rotationally driven in the direction of arrow R at a predetermined peripheral speed (process speed).

A charging roller (charging member) <NUM> supplied with a bias voltage is applied contacts an outer peripheral surface of the drum <NUM> and uniformly charges the outer peripheral surface of the drum <NUM>. The charging roller <NUM> is a rotatable member (roller) capable of rotating in contact with the drum <NUM>. The charging member is not limited to such a member having a rotatable contact type roller structure, but a charging member (charging device) fixed with a space from the drum <NUM>, such as a corotron* charging device, may be used.

The exposure device <NUM> outputs a laser beam L in accordance with image information. The laser beam L passes through a laser opening <NUM> provided in a cleaning frame <NUM> of the cartridge B to scan and expose the outer peripheral surface of the drum <NUM>. By this, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the drum <NUM>.

On the other hand, as shown in <FIG>, in the developing unit <NUM> as the developing device, the toner T in a toner chamber <NUM> is stirred and fed by rotation of a feeding member (stirring member) <NUM>, and fed to the toner supply chamber <NUM>.

The toner T is carried on a surface of a developing roller <NUM> by a magnetic force of a magnet roller <NUM> (fixed magnet). The developing roller <NUM> is a developer carrying member which carries a developer (toner T) to develop the latent image (electrostatic latent image) formed on the drum <NUM>. In this embodiment, a non-contact developing method is used with which a latent image is developed with a small gap between the surfaces of the developing roller <NUM> and the drum <NUM>. It is also possible to employ a contact developing system in which the latent image is developed while the developing roller <NUM> is in contact with the drum <NUM>.

The toner T is triboelectrically charged by a developing blade <NUM>, and a toner layer thickness on the peripheral surface of the developing roller <NUM> as a developer carrying member is regulated.

The toner T is supplied to the drum <NUM> in accordance with the electrostatic latent image to develop the latent image. By this, the latent image is visualized into a toner image. The drum <NUM> is an image bearing member which carries the latent image or the visualized image (toner image, developer image) formed with toner (developer image) on the surface thereof.

In addition, the drum <NUM> and the developing roller <NUM> are rotatable members (rotating members) which can rotate while carrying a developer (toner) on the surface thereof.

As shown in <FIG>, the sheet material PA stored in the lower portion of the apparatus main assembly A from the sheet tray <NUM> is picked up by the pickup roller 5a, and fed out by the feeding roller pair 5b, and the feeding roller pair 5c in timed relation with the output timing of the laser beam L. Then, the sheet material PA is fed to the transfer position formed between the drum <NUM> and the transfer roller <NUM> by way of the transfer guide <NUM>. At this transfer position, the toner image is sequentially transferred from the drum <NUM> to the sheet material PA.

The sheet material PA now having the toner image transferred is separated from the drum <NUM> and fed to the fixing device <NUM> along a conveyance guide <NUM>. Then, the sheet material PA passes through a nip portion between the heating roller 9a and the pressure roller 9b which form the fixing device <NUM>. Pressure and heat fixing processing is effected in this nip portion, so that the toner image is fixed on the sheet material PA. The sheet material PA which has been subjected to the toner image fixing process is fed to the discharge roller pair <NUM> and is discharged to the discharge tray <NUM>.

On the other hand, as shown in <FIG>, residual toner on the outer peripheral surface of the drum <NUM> after the image transfer is removed by a cleaning blade <NUM>, and is used again in the image forming process. The toner removed from the drum <NUM> is stored in a waste toner chamber 71b of a toner cleaning unit <NUM>. The cleaning unit <NUM> is a unit including a photosensitive drum <NUM>.

In the above description, the charging roller <NUM>, the developing roller <NUM>, the transfer roller <NUM>, and the cleaning blade <NUM> are process means (process members, acting members) that act on the drum <NUM>.

Referring to <FIG>, <FIG> and <FIG>, the overall structure of the cartridge B will be described. <FIG> is a sectional view of the cartridge B, and <FIG> and <FIG> are perspective views illustrating the structure of the cartridge B. In this embodiment, description will be made while omitting screws for connecting the parts.

The description of an operating unit including a lever member will be made later, and the description thereof is omitted here.

The cartridge B includes the cleaning unit.

As shown in <FIG>, the cleaning unit <NUM> includes a drum <NUM>, a charging roller <NUM>, a cleaning member <NUM>, and a cleaning frame <NUM> which supports them. On the drive side of the drum <NUM>, a drive side drum flange <NUM> provided on the drive side is rotatably supported by a hole 73a of a drum bearing <NUM>. In a broad sense, the drum bearing <NUM>, the side member <NUM>, and the cleaning frame <NUM> can be collectively referred to as a cleaning frame.

On the non-driving side, as shown in <FIG>, the hole (not shown) of the non-driving side drum flange is rotatably supported by the drum shaft <NUM> press-fitted into the hole 71c provided in the cleaning frame <NUM>.

In the cleaning unit <NUM>, the charging roller <NUM> and the cleaning member <NUM> are provided in contact with the outer peripheral surface of the drum <NUM>.

The cleaning member <NUM> includes a rubber blade 77a which is a blade-shaped elastic member formed of rubber as an elastic material, and a support member 77b which supports the rubber blade. The rubber blade 77a is in contact with the drum <NUM> in the counter direction with respect to the rotational direction of the drum <NUM>. That is, the rubber blade 77a is in contact with the drum <NUM> so that the free end surface thereof faces an upstream side in the rotational direction of the drum <NUM>.

As shown in <FIG>, the waste toner removed from the surface of the drum <NUM> by the cleaning member <NUM> is stored in the waste toner chamber 71b formed by the cleaning frame <NUM> and the cleaning member <NUM>.

In addition, as shown in <FIG>, a scooping sheet <NUM> for preventing the waste toner from leaking from the cleaning frame <NUM> is provided at an edge portion of the cleaning frame <NUM> so as to contact the drum <NUM>.

The charging roller <NUM> is rotatably mounted to the cleaning unit <NUM> by way of charging roller bearings (not shown) at the opposite ends in the longitudinal direction of the cleaning frame <NUM>.

The longitudinal direction of the cleaning frame <NUM> (longitudinal direction of the cartridge B) is substantially parallel with the direction in which the rotation axis of the drum <NUM> extends (axial direction). Hereinafter, unless otherwise specified, the longitudinal direction or the axial direction is intended to mean the axial direction of the drum <NUM>.

The charging roller <NUM> is pressed against the drum <NUM> by urging the charging roller bearing <NUM> toward the drum <NUM> by the urging member <NUM>. The charging roller <NUM> is rotated by the rotation of the drum <NUM>.

As shown in <FIG>, the developing unit <NUM> includes a developing roller <NUM>, a developing container <NUM> which supports the developing roller <NUM>, a developing blade <NUM>, and the like. The developing roller <NUM> is rotatably mounted to the developing container <NUM> by bearing members <NUM> (<FIG>) and bearing members <NUM> (<FIG>) provided at the opposite ends.

The magnet roller <NUM> is provided inside the developing roller <NUM>. In the developing unit <NUM>, the developing blade <NUM> for regulating the toner layer on the developing roller <NUM> is provided. As shown in <FIG> and <FIG>, a spacing member <NUM> is mounted to each of the opposite ends of the developing roller <NUM>, and the spacing member <NUM> and the drum <NUM> are in contact to each other, so that a small gap is maintained between the surfaces of the developing roller <NUM> and the drum <NUM>. In addition, as shown in <FIG>, a blow-out prevention sheet <NUM> for preventing the toner from leaking from the developing unit <NUM> is provided at an edge of a bottom member <NUM> so as to contact the developing roller <NUM>. Further, a feeding member <NUM> is provided in a toner chamber <NUM> formed by the developing container <NUM> and the bottom member <NUM>. The feeding member <NUM> stirs the toner contained in the toner chamber <NUM> and transports the toner to the toner supply chamber <NUM>.

As shown in <FIG> and <FIG>, the cartridge B is structured by combining the cleaning unit <NUM> and the developing unit <NUM>.

When connecting the developing unit and the cleaning unit with each other, the center of the first development supporting boss 26a of the developing container <NUM> with respect to the first driving-side hanging hole 71i of the cleaning frame <NUM>, and the center of the second development supporting boss 23b with respect to the second non-driving-side hanging hole 71j are first aligned with each other. Specifically, by moving the developing unit <NUM> in the direction of arrow G, the first development supporting boss 26a and the second development supporting boss 23b are fitted into the first hanging hole 71i and the second hanging hole 71j. By this, the developing unit <NUM> is movably connected to the cleaning unit <NUM>. More specifically, the developing unit <NUM> is rotatably (rotatably) connected with the cleaning unit <NUM>. Then, the side member <NUM> is assembled to the cleaning unit <NUM> to form the cartridge B.

In this embodiment, the driving side biasing member <NUM> (<FIG>) and the non-driving side biasing member 46R (<FIG>) are formed by compression springs. The developing unit <NUM> is urged by the cleaning unit <NUM> by the urging force of these springs, and the developing roller <NUM> is reliably pressed toward the drum <NUM>. The developing roller <NUM> is held at a predetermined distance from the drum <NUM> by the distance holding members <NUM> mounted to both ends of the developing roller <NUM>.

Next, referring to parts (a), (b) and (c) of <FIG>, parts (a) and (b) of <FIG>, and parts (a) and (b) of <FIG>, mounting of the attachment to the apparatus main assembly A will be described. Here, <FIG> is a perspective view of the drive side of the apparatus main assembly A. <FIG> are cross-sectional views of the apparatus main assembly A of <FIG> taken along the drive transmission member <NUM>. <FIG> are perspective views of the attachment <NUM>. <FIG> is a perspective view before the attachment <NUM> is mounted to the apparatus main assembly A. <FIG> is a perspective view when the attachment <NUM> is mounted to the apparatus main assembly A. <FIG> is a sectional view of <FIG> taken along the drive transmission member <NUM>.

First, the positional relationship of the drive transmission member (drive output member) <NUM> with respect to the drive-side guide frame R200 of the apparatus main assembly A and the method of supporting the drive transmission member <NUM> by the drive transmission member bearing <NUM> will be described.

The drive transmission member <NUM> is a member (driving shaft, apparatus main assembly side coupling member) for transmitting the driving force to the cartridge B by being connected to the cartridge B.

As shown in <FIG>, a drive transmission member hole 200a is provided in the guide frame R200, and the drive transmission member <NUM> is placed in the drive transmission member hole 200a. As shown in <FIG>, the drive transmission member <NUM> is supported by the drive transmission member bearing <NUM> at the end portion in the axial direction. At this time, the outer peripheral surface 81e of the drive transmission member <NUM> forms a gap M between itself and the drive transmission member hole 200a. Actually, as shown in <FIG>, the drive transmission member <NUM> is inclined (tilted) by the amount through which it can move in the gap M, due to its own weight or the like.

If the drive transmission member <NUM> is inclined, it may be difficult to connect the drive transmission member <NUM> to the cartridge B depending on the structure of the cartridge B. Therefore, in this embodiment, the attachment <NUM> is mounted to the drive transmission member <NUM> to suppress the inclination of the drive transmission member <NUM>. Although the details will be described hereinafter, the attachment <NUM> suppresses the inclination of the drive transmission member <NUM> by filling the gap M.

As shown in <FIG>, the main assembly of the attachment <NUM> is a cylindrical portion having a cylindrical shape. The cylindrical portion (cylindrical shape) has an inner peripheral surface 100a and an outer peripheral surface 100b. A grip portion 100c is provided so as to project from the outer surface 100b in a direction intersecting with the axis L1 of the cylinder portion (outside in a radial direction of the cylinder portion). The grip portion 100c is provided with a through hole 100d and a projection 100e. The grip portion 100c projects in a direction substantially perpendicular to the axis L1. The axis L1 is an imaginary line extending through the center of the cylindrical portion.

The inside of the cylindrical portion (cylindrical shape) of the attachment <NUM> is a space, and opposite ends in the axial direction of the cylindrical shape are open. That is, the inner space of the cylindrical shape can be accessed from both ends of the cylinder.

Next, a mounting process of the attachment <NUM> to the apparatus main assembly A will be described. As shown in <FIG>, by inserting a finger into the through hole 100d provided in the grip portion 100c and by griping the projection 100e with the finger, the attachment <NUM> can be inserted into the gap M is formed between the drive transmission member <NUM> and the drive transmission member hole 200a. By placing the attachment <NUM> around the drive transmission member <NUM>, the inclination of the drive transmission member <NUM> is suppressed (the inclination angle becomes smaller).

The projection 100e is a protrusion (projection) provided so that the user can easily grip the grip 100c. Similarly, the through hole 100d is also an opening (space) provided so that the user can easily grip the grip portion 100c. Both the projection 100e and the opening (the through hole 100d) are not necessarily required for the grip 100c. For example, even if there is provided one of them, it is effective to facilitate the user's gripping the grip portion 100c. Further, in this embodiment, the opening provided in the grip portion 100c is the hole 100d surrounded by the grip portion 100c all around, but the opening is not limited to such a shape, and other shapes are usable as long as it is a space into which the user can insert his/her finger.

Next, a mounting completion position of the attachment <NUM> relative to the apparatus main body A will be described. As shown in <FIG>, the position of the attachment <NUM> in the longitudinal direction (axial direction) with respect to the apparatus main assembly A can be determined by a longitudinal regulation portion (position regulation portion) 100f. The longitudinal regulation surface 200b of the guide frame R200 and the longitudinal regulation portion 100f provided on the holding portion 100c of the attachment are brought into contact with each other. By this, the position of the attachment <NUM> can be determined, and the attachment <NUM> can be prevented from entering the back of the guide frame R200. The longitudinal direction of the attachment <NUM> is the axial direction of the cylindrical portion of the attachment <NUM> (direction parallel to the axis L1).

Further, the outer peripheral surface 81e of the drive transmission member <NUM> and the inner peripheral surface 100a of the attachment <NUM> are in contact with each other. Therefore, as shown in <FIG>, when the drive transmission member <NUM> is rotated by the drive motor (not shown) of the main assembly, the attachment <NUM> tends to rotate about the axis of the drive transmission member <NUM>. However, the rotation of the attachment <NUM> can be restricted (suppressed) by the rotation restricted surface 200c of the guide frame R200 and the rotation restricting portion <NUM> provided on the grip 100c of the attachment <NUM> contacting each other.

The description will be made as to that coupling member <NUM> and the advancing/retreating mechanism portion for advancing/retreating the coupling member. The coupling member <NUM> is a member (drive input member, input coupling) for receiving the driving force (rotational force) for rotating the drum <NUM> and the developing roller <NUM> from the outside of the cartridge (that is, the image forming apparatus main assembly).

<FIG> is a perspective view of the drive transmission member (drive output member) <NUM>. As shown in this Figure, the drive transmission member <NUM> is provided with a recess (drive transmission portion 81a) having a substantially triangular shape. The driven transmission portion 64a of the coupling member <NUM> is engaged with the recess (drive transmission portion 81a), so that the coupling member <NUM> receives the driving force. Referring to <FIG>, the drive side flange unit <NUM> will be described.

The drive side flange unit <NUM> in this embodiment includes the coupling member <NUM>, a drive side flange member <NUM>, a lid member <NUM>, and a first pressing member <NUM>. The coupling member <NUM> includes the driven transmission portion (driving force receiving portion) 64a and the driving transmission portion 64b. The driving force is transmitted from the drive transmission member (drive output member) <NUM> (<FIG> and <FIG>) of the apparatus main assembly A to the driven transmission portion 64a. The drive transmitting portion 64b is supported by the drive side flange member <NUM> and at the same time transmits drive to the drive side flange member <NUM>.

The drive side flange member <NUM> comprises a gear portion 75a which transmits the drive to a gear member <NUM> (<FIG>) provided at the end portion of the developing roller, a coupling support portion 75b (<FIG>), and the like. After the coupling member <NUM> is inserted to the inner periphery (coupling support portion 75b) of the driving side flange member <NUM>, the first pressing member <NUM> for urging the coupling member <NUM> toward the driving side is inserted. Thereafter the, the lid member <NUM> is fixed to the end portion 75c of the driving side flange member <NUM> by means such as welding, so that the driving side flange unit <NUM> is structured.

<FIG> is a perspective view of the driving side flange member <NUM> and the coupling member <NUM>. A The inner peripheral surface of the driving side flange member <NUM> functions as a coupling support portion 75b. The drive-side flange member <NUM> supports the coupling member <NUM> by supporting the outer peripheral surface of the coupling member <NUM> on the inner peripheral surface (coupling support portion 75b). In addition, of the outer peripheral surface of the coupling member <NUM>, two surfaces symmetrically arranged with respect to the rotation axis are flat portions. This flat surface portion functions as the drive transmission portion 64b of the coupling member <NUM>. The inner peripheral surface 75b of the flange member <NUM> is also provided with two flat surface portions 75b1 corresponding to the drive transmission portion 64b. The flat surface portion of the flange member <NUM> functions as the driven transmission portion 75b1 of the flange member <NUM>. That is, the driving force is transmitted from the coupling member <NUM> to the flange member <NUM> by the drive transmission portion 64b of the coupling member <NUM> contacting the transmitted portion 75b1 of the flange member <NUM>.

The drive side flange <NUM> of the drive side flange unit <NUM> is fixed to the end portion of the photosensitive drum <NUM> by means such as press fitting or clamping (<FIG>). By this, the driving force (rotational force) received by the coupling member <NUM> from the drive transmission member <NUM> (<FIG> and <FIG>) is transmitted to the photosensitive drum <NUM> by way of the drive side flange <NUM>.

Next, <FIG> is an exploded perspective view of the cartridge. As shown in <FIG>, the driving force (rotational force) is transmitted from the driving side flange <NUM> also to the developing roller <NUM> by way of the gear 75a. That is, the gear 75a is in meshing engagement with the developing roller gear <NUM> to transmit the rotation of the driving side flange <NUM> to the developing roller gear <NUM>. The developing roller gear <NUM> is provided on the developing roller <NUM>, and more specifically, is engaged with a shaft portion of a developing roller flange <NUM> fixed to the end portion of the developing roller <NUM>. Therefore, the rotation of the developing roller gear <NUM> is transmitted to the developing roller <NUM> by way of the developing roller flange <NUM>. Further, the developing roller gear <NUM> also transmits the drive to the feeding member gear <NUM> by way of the idler gear <NUM>. The feed member gear <NUM> is provided on the feed member <NUM> (<FIG>), and when the feed member gear <NUM> rotates, the feed member <NUM> also rotates.

That is, the drive side flange <NUM> functions as a drive transmission member (cartridge side drive transmission member) for transmitting drive from the coupling member <NUM> to the drum <NUM>, the developing roller <NUM>, the conveyance member <NUM>, and the like. In this embodiment, the driven transmission portion 64a of the coupling member <NUM> has a projection shape (projected portion) with a substantially triangular cross-section. Specifically, a substantially triangular cross-section twisted counterclockwise about the axis of the photosensitive member drum from the driving side to the non-driving side is employed. However, the shape of the driven transmission portion 64a is not limited to such a shape as long as it can engage the driving transmission member <NUM> (<FIG>) and can receive a driving force. In this embodiment, the drive transmission member <NUM> of the apparatus main assembly A is provided with a substantially triangular recess (drive transmission portion 81a, <FIG>) which can be engaged with the driven transmission portion 64a. Therefore, the driven transmission portion 64a has a projection shape which engages with the recess portion. The projection shape may be plural rather than singular, and the shape is not limited to the triangle. In addition, although the projection shape has been described as having a twisted triangular shape, it does not necessarily have to be twisted.

As shown in <FIG>, the coupling member <NUM> is structured to be movable forward and backward and forth along the longitudinal direction (axial direction). <FIG> shows a state in which the coupling member is retracted and disengaged from the drive transmission member <NUM>. In <FIG>, the coupling member <NUM> is advanced and engaged with the drive transmission member <NUM>. It shows a state of match Further, <FIG> shows a state (a process of forward/backward movement) between <FIG>.

Therefore, next, an operating unit (an operating mechanism, an advancing/retreating unit, an advancing/retreating mechanism) that enables such a longitudinal movement of the coupling member <NUM> will be described referring to <FIG>, <FIG>, and <FIG>.

<FIG> is a partial perspective view illustrating the structure of the operation unit provided in the cleaning unit <NUM> according to this embodiment.

<FIG> is a partial longitudinal cross-sectional view of the drum unit driving side end portion according to this embodiment.

<FIG> is a partial perspective view illustrating the operation unit according to the present embodiment similarly to <FIG>.

As shown in <FIG>, the operating unit includes an outer cylindrical cam member <NUM>, an inner cylindrical cam member <NUM>, a lever member <NUM>, a second pressing member (elastic member, biasing member) <NUM>, and the like. The operation unit is a control mechanism (control unit) that is connected to the coupling member <NUM> and controls the movement (advancing/retreating movement) of the coupling member <NUM>.

The outer cylindrical cam member <NUM> comprises a cylindrical cam portion 70b and a lever member engaging portion 70a for engaging the lever member <NUM>. Like the outer cylindrical cam member <NUM>, the inner cylindrical cam member <NUM> contacts the cylindrical cam portion 70b and the coupling member <NUM> to restrict the longitudinal position of the coupling member <NUM> from the coupling member <NUM> longitudinal position regulating surface 74d and the like.

As shown in <FIG> and <FIG>, in this embodiment, the outer cylindrical cam member <NUM> and the inner cylindrical cam member <NUM> are structured to be supported by the outer peripheral portion 73a of the drum bearing member <NUM>. The lever member engaging portion 70a of the outer cylindrical cam member <NUM> is structured to be exposed to the outside of the drum bearing member <NUM> (<FIG>).

After the developing unit <NUM> is supported by the cleaning unit <NUM>, the engaged portion 12b provided at one end of the lever member <NUM> is engaged with the lever member engaging portion 70a of the outer cylindrical cam member <NUM>. Further, the lever member <NUM> is arranged such that the slide target portion 12c at the other end is positioned between the slide ribs <NUM> provided on the cleaning frame <NUM>. That is, the projection-shaped engaging portion 70a enters the inside of the hole-shaped engaged portion 12b to engage with each other, so that the lever member <NUM> is connected to the outer cylindrical cam member <NUM>.

After the lever member <NUM> is positioned, the second pressing member <NUM> which presses and urges the lever member <NUM> is placed between the cleaning frame <NUM> and the lever member <NUM>. In this embodiment, the torsion coil spring is used as the second pressing member (urging member) <NUM>, but the present invention is not limited to such an example. For example, an elastic member (spring) having a different structure such as a compression coil spring can be preferably used.

By fixing the side member <NUM> to the cleaning frame <NUM>, a process cartridge including the operation unit according to this embodiment is structured.

This operating unit is connected to the coupling member <NUM> at the inner cylindrical cam <NUM>, and the coupling member <NUM> can be moved forward and backward (moved) by operating the lever member <NUM>. Although the detailed operation principle will be described hereinafter, since the lever member <NUM> is connected to the outer cylindrical cam member <NUM>, the outer cylindrical cam <NUM> is rotated by the lever member <NUM> moving in a substantially linear manner. The outer cylindrical cam <NUM> is in contact with the inner cylindrical cam <NUM>, and the rotational movement of the outer cylindrical cam <NUM> causes the inner cylindrical cam <NUM> to move forward and backward in the longitudinal direction. The inner cylindrical cam <NUM> is in contact with the coupling member <NUM>, and the forward/backward movement of the inner cylindrical cam <NUM> and the forward/backward movement of the coupling member <NUM> are interrelated with each other.

That is, the lever member <NUM> is functionally (indirectly and operatively) connected to the coupling member <NUM> by way of the outer cylindrical cam member <NUM> and the inner cylindrical cam member <NUM>, so that the lever member <NUM> and the coupling member <NUM> are interrelated with each other.

Referring to <FIG> and <FIG>, the movement of the coupling member <NUM> to advance and retreat in interrelation with the movement of the lever member <NUM> will be described. The lever member <NUM> is structured to move by contact with and separation from a cartridge pressing member (pressing force applying member) provided in the apparatus main assembly A.

<FIG> is a side view of a process cartridge B according to this embodiment.

<FIG> is a sectional view of the image forming apparatus in a state before the opening/closing door <NUM> of the apparatus main assembly is opened and the process cartridge B is mounted to the apparatus main assembly A.

<FIG> is a cross-sectional view of the image forming apparatus after the mounting of the process cartridge B in the apparatus main assembly A is completed and before the opening/closing door <NUM> is closed.

<FIG> is a cross-sectional view of the image forming apparatus in a state in which the cartridge pressing member <NUM> starts to contact the pressed portion 12a of the lever member <NUM> in the process of closing the opening/closing door <NUM> of the apparatus main assembly A in the direction H.

<FIG> is a sectional view of the image forming apparatus in which the opening/closing door <NUM> of the apparatus main assembly A is completely closed.

<FIG> is a perspective view of the lever member <NUM>, the outer cylindrical cam member <NUM>, and the inner cylindrical cam member <NUM> in this embodiment. Here, Figure 13A is a perspective view in the state (<FIG>, <FIG>, <FIG>) before the cartridge pressing member <NUM> contacts the pressed portion 12a of the lever member <NUM>. <FIG> is a perspective view in the state where the opening/closing door <NUM> is completely closed and a predetermined pressure of the cartridge pressing spring <NUM> is applied to the contact portion 12a of the lever member <NUM> (<FIG>). <FIG> is a perspective view in a state between the states shown in <FIG> (<FIG>).

<FIG> is a longitudinal sectional view of the drive transmission member <NUM> and the coupling member <NUM> of the apparatus main assembly A according to this embodiment, as described above. Similar to <FIG>, here, <FIG> is a longitudinal sectional view of a state (<FIG>, <FIG>, and <FIG>) before the cartridge pressing member contacts the pressed portion 12a of the lever member <NUM>. <FIG> is a longitudinal sectional view in a state where the opening/closing door <NUM> is completely closed and a predetermined pressure of the cartridge pressing spring <NUM> is applied to the contact portion 12a of the lever member <NUM> ((<FIG>)). Figure 14B is a longitudinal sectional view in a state between the states shown in Figures 14A and 14C (<FIG>). As shown in <FIG>, the process cartridge B is mounted to the apparatus main assembly A after it is opened by rotating the opening/closing door <NUM> of the apparatus main assembly A about the rotation center 13X. The opening/closing door <NUM> is an opening/closing member for opening and closing a cartridge mounting portion (space for mounting the cartridge) provided inside the apparatus main assembly A. The mounting portion is provided with guide rails (guide members) <NUM> and <NUM> for guiding the guided portions 76c and <NUM> of the process cartridge B, and the cartridge B is mounted to the apparatus main assembly A along the guide rails <NUM> and <NUM> (only the drive side is shown). As shown in <FIG>, the mounting of the process cartridge B is completed when the positioned portions 73d and 73f provided on the drum bearing member <NUM> are brought into contact with the apparatus main assembly positioning portions 15a and 15b or inserted to the neighborhood thereof.

Two cartridge pressing members <NUM> are mounted at respective ends of the opening/closing door <NUM> in the axial direction (<FIG>). The two cartridge pressing members <NUM> are movable with respect to the opening/closing door <NUM> within a certain range.

The two cartridge pressing springs <NUM> are mounted to respective ends in the longitudinal direction of the front plate <NUM> provided in the main assembly A of the apparatus. The cleaning frame <NUM> is provided with the cartridge pressed portions 71e, which function as urging force receiving portions of the cartridge pressing spring <NUM>, at respective the longitudinal ends. As will be described hereinafter, when the opening/closing door <NUM> is completely closed, a predetermined pressure F2 is applied from the cartridge pressing spring <NUM> to the cartridge pressed portion 71e and the lever member pressed portion 12a.

Next, the forward/backward movement of the coupling member <NUM> (driven member) will be described. In the state before the cartridge pressing member <NUM> abuts the lever member <NUM> (<FIG>, <FIG>, and <FIG>), the lever member <NUM> is urged by the second pressing member <NUM> (<FIG>) in the E direction in <FIG>.

The outer cylindrical cam member <NUM>, which is engaged with the lever member <NUM> and is rotatably supported around the drum axis, is urged in the G direction in <FIG>. The outermost projecting surface 70c of the outer cylindrical cam member <NUM> contacts the innermost projecting surface 74c of the inner cylindrical cam member <NUM>.

As shown in <FIG>, the coupling member <NUM> is urged toward the drive side by the first pressing member <NUM>, and the coupling contact portion 64c is pressed against the coupling member longitudinal position restricting surface 74d of the inner cylindrical cam member <NUM>. That is, the longitudinal position of the coupling member <NUM> is also determined depending on the longitudinal position of the inner cylindrical cam member <NUM> (position in the longitudinal direction). The first pressing member <NUM> is used to operate the coupling member <NUM> on the driving side, and therefore, the first pressing member <NUM> can also be regarded as a portion of the above-described operating unit. In this embodiment, the compression coil spring is used as the first pressing member <NUM>, but it is also possible to urge the coupling member <NUM> using an elastic member having another shape.

When the cartridge B is not mounted to the apparatus main assembly A, the inner cylindrical cam member <NUM> retracts the coupling member <NUM> into the drum against the elastic force of the first pressing member <NUM>. That is, the structure is such that in the state in which the main assembly door <NUM> is released as shown in <FIG> and <FIG>, or in the state before the cartridge pressing member <NUM> abuts on the lever member <NUM>, the coupling member <NUM> is placed at the most non-driving side. , The position where the coupling member <NUM> is retracted to the nondriving side (that is, the inner side of the cartridge B) is referred to as a first position (retracted position, inner position, disengaged position, disengaged position). As shown in <FIG>, the structure is such that when the coupling member <NUM> is at the first position, the driven transmission portion 64a of the coupling member <NUM> and the driving transmission portion 81a of the drive transmission member <NUM> overlap in the longitudinal direction. That is, the process cartridge B can be smoothly mounted and dismounted to from the apparatus main assembly A without interference between the coupling member <NUM> and the drive transmission member <NUM> of the device main body.

When the opening/closing door <NUM> is closed after the cartridge B is mounted to the apparatus main assembly A, the cartridge pressing member <NUM> provided on the opening/closing door <NUM> contacts the lever member <NUM>. The pressing of the pressing member <NUM> starts the movement of the lever member <NUM>. The coupling member <NUM> moves from the first position (retracted position) to the drive side in interrelation with the movement of the lever member <NUM>, the movement will be described below.

As shown in <FIG>, when the mounting of the process cartridge B is completed and the opening/closing door <NUM> is closed in the direction H in the Figure, the contact between the cartridge pressing member <NUM> and the lever member <NUM> starts, the pressing force of the cartridge pressing spring <NUM> begins to act on the lever member12. By this pressing force, the lever member <NUM> starts to move in the K direction in the Figure against the urging force (elastic force) of the second pressing member <NUM>. As shown in <FIG>, when the lever member <NUM> moves in the K direction, the outer cylindrical cam member <NUM> engaged with the lever member <NUM> starts to rotate in the M direction in the Figure.

The inner cylindrical cam member <NUM> is adjacent to the outer cylindrical cam member <NUM>. The inner cylindrical cam member <NUM> is not rotatable but is capable of moving only in the axial direction. The rotation of the outer cylindrical cam member <NUM> in the M direction brings the cylindrical cam portion 70b of the outer cylindrical cam member <NUM> and the cylindrical cam portion 74b of the inner cylindrical cam member <NUM> to contact each other at the slanted surfaces thereof. Then, the inner cylindrical cam member <NUM> starts to move toward the drive side (N direction) along the longitudinal direction by the pressing force of the first pressing spring member <NUM>. When the inner cylindrical cam member <NUM> moves in the N direction, the coupling member <NUM> pressed by the first pressing spring member <NUM> is also allowed to move in the longitudinal direction. By this movement of the coupling member <NUM>, the coupling member <NUM> advances toward the driving side (that is, the outside of the cartridge B). Then, the driven transmission portion 64a of the coupling member <NUM> becomes engageable with the driving transmission portion 81a of the driving transmission member of the apparatus main body in the longitudinal direction (<FIG>). Further, when the opening/closing door <NUM> is completely closed (state of <FIG>), the phases of the cylindrical cam portions of the outer cylindrical cam member <NUM> and the inner cylindrical cam member <NUM> are aligned with each other as shown in <FIG>. At this time, the inner cylindrical cam member <NUM> and the coupling member <NUM> are placed on the most drive side by the urging force of the first pressing member <NUM>. In this embodiment, the position where the coupling member <NUM> advances toward the drive side is referred to as a second displacement (advance position, outer position, engagement position, drive transmission position).

As shown in <FIG>, as described above, the attachment M reduces the gap M, so that the drive transmission member <NUM> can be prevented from tilting. Therefore, when the coupling member <NUM> moves to the second position, the driven transmission portion 64a of the coupling member <NUM> and the driving transmission portion 81a of the drive transmission member <NUM> can be reliably engaged.

In the embodiment, the attachment of the attachment <NUM> to the apparatus main assembly A and the suppressing of the tilting of the drive transmission member <NUM>, and the resulting assured engagement between the driven transmission portion 64a of the coupling member <NUM> and the drive transmission portion 81a of the drive transmission member <NUM> have been described.

Further, referring to <FIG> and <FIG> <FIG>, a method of fixing the attachment <NUM> to the guide frame R200 and a method of improving the dismountability of the attachment <NUM> will be described. <FIG> is a perspective view of the attachment <NUM>, <FIG> is a cross-sectional view of the apparatus main assembly A cut by the drive transmission member <NUM>, and <FIG> is an enlarged view of a longitudinal retaining portion <NUM> shown in <FIG>. <FIG> is a perspective view of the apparatus main assembly A and the attachment <NUM>.

Regarding the method of fixing the attachment <NUM> to the guide frame R200, the following method can be employed in place of the above-described fixing method or in addition to the above-described fixing method. As shown in <FIG>, the double-sided tape <NUM> may be mounted to the longitudinal restriction portion 100f of the attachment <NUM> and fixed to the longitudinal restriction surface 200b (<FIG>) of the guide frame R200. In addition, as shown in <FIG>, the attachment <NUM> is provided with a longitudinal retaining portion <NUM> projecting outward in the radial direction with respect to the outer peripheral portion 100b and engaging with the portion 200d of the guide frame R200.

The retaining portion <NUM> is a snap fit having a cantilever structure, and can be engaged with and disengaged from the longitudinal retaining portion 200d by elastically deformation thereof.

Further, in order to improve the dismountability of the attachment <NUM> from the apparatus main body A, a hook portion 100i may be provided between the longitudinal regulation portion 100f and the projection portion 100e of the attachment <NUM>, as shown in <FIG>.

In order to improve the stiffness of the attachment <NUM>, a reinforcing rib 100j (projection) may be provided on the outer peripheral surface 100b of the attachment <NUM>, as shown in <FIG> and <FIG>.

As shown in <FIG>, when the attachment <NUM> is mounted to the apparatus main assembly A, if the gripping portion 100c of the attachment <NUM> projects inward in the longitudinal direction beyond the cartridge facing surface 200e of the guide frame R200 (<FIG>), interfere with cartridge B results. Therefore, the grip portion 100c needs to be kept outside the cartridge facing surface 200e (<FIG>) in the longitudinal direction. The shape of the grip portion 100c of the attachment <NUM> at this time satisfies the following relationship. Assuming that the diameter of the outer circumference of the attachment <NUM> is t, a circle having a diameter (4t) four times as large as the outer circumference of the cylindrical portion and concentric with the cylindrical portion of the attachment <NUM> is drawn in a plane perpendicular to the axis of the attachment as shown in <FIG>. Then, the entire grip portion 100c is included inside the circle having the diameter of 4t. That is, the distance from the center of the cylindrical portion of the attachment <NUM> to an arbitrary point on the grip portion 100c is smaller than 2t.

Further, the area occupied by the connecting portion <NUM> (<FIG>) for connecting the outer peripheral surface 100b and the grip portion 100c satisfies x°< <NUM>°. That is, in the plane perpendicular to the axis of the attachment <NUM>, the entire connecting portion <NUM> is included in an area having an angle smaller than <NUM> degrees with respect to the center of the attachment <NUM> (center of the cylindrical portion).

As described above, according to this embodiment, by mounting the attachment <NUM> around the drive transmission member <NUM>, it is possible to prevent the drive transmission member <NUM> from tilting (parts (a), (b) and (c) <FIG>, and <FIG>). That is, the attachment <NUM> prevents the drive transmission member <NUM> from tilting relative to the coupling member <NUM> of the cartridge B. By this, the drive transmission member <NUM> and the coupling member <NUM> can be smoothly connected. In this embodiment, the coupling member <NUM> is connected (coupling, engaged) to the drive transmission member <NUM> (<FIG>) by the coupling member <NUM> movable forward and backward advancing toward the drive transmission member <NUM>.

Both the cartridge B and the attachment <NUM> described above are dismountably mountable units which can be mounted to and dismounted from the image forming apparatus main assembly, and a set (combination) of the cartridge B and the attachment <NUM> is called an attach/dismount unit set. By selling such two dismountably mountable units in combination as a set, the user can attach the attachment <NUM> to the apparatus main assembly and then attach the cartridge B to the apparatus main assembly.

As shown in <FIG>, the relation between the inner diameter y of the inner peripheral surface 100a of the attachment <NUM> and the outer diameter z of the photosensitive drum <NUM> is preferably y > z.

As shown in <FIG>, the distance u from the center (axis) of the cylindrical shape of the attachment <NUM> to the most remote point (outermost portion) of the grip 100c on the surface perpendicular to the rotation axis of the photosensitive drum <NUM> is determined. Further, the distance s from the center (axis) of the photosensitive drum <NUM> to the center (axis) of the developing roller <NUM> is determined (<FIG>). The relationship between the distances u and s is preferably u > s.

As shown in <FIG>, the cylindrical shape of the attachment <NUM> does not have to be a perfect cylinder. In <FIG>, the cylinders are not completely connected over <NUM> degrees, and a part of the cylinder is disconnected. That is, the cylinder shown in <FIG> has a C shape, but such a cylinder can be regarded as a substantially cylindrical shape. Further, a flat surface portion <NUM> (<FIG>) may be provided on a part of the outer diameter surface 100b of the attachment <NUM>. Such an attachment can also be regarded as a substantially cylindrical shape.

Further, the grip may not be provided with the through hole 100d (<FIG>). Further, the grip portion 100c of the attachment <NUM> is not limited to the example of the plate shape as shown in Figure. For example, as shown in <FIG>, the grip portion 100c of the attachment <NUM> may have a ring shape.

According to the present invention, an attachment, a dismountably mountable unit set, an electrophotographic image forming apparatus, and a cartridge mounting method which are useful for the electrophotographic image forming apparatus are provided.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made. Therefore, the following claims are attached to define the scope of the present invention.

Claim 1:
A mountable unit set usable with an electrophotographic image forming apparatus, said mountable unit set comprising:
a cartridge (B) detachably mountable to an apparatus main assembly (A) of the electrophotographic image forming apparatus, said cartridge (B) including a photosensitive drum (<NUM>), and a coupling member (<NUM>) for receiving a driving force for rotating the photosensitive drum (<NUM>) from a driving shaft (<NUM>) provided in the apparatus main assembly (A), and
an attachment (<NUM>) detachably mountable to the apparatus main assembly (A) and including a cylindrical portion configured to be mounted around the driving shaft (<NUM>) to suppress tilting of the driving shaft (<NUM>),
wherein said attachment (<NUM>) is provided with a grip portion (100c) extending from said cylindrical portion toward an outside in a radial direction of said cylindrical portion,
characterized in that
an entirety of a connecting portion (<NUM>) between the cylindrical portion and the grip portion (100c) is within a range smaller than <NUM> degrees about the axis of cylindrical portion, in a plane perpendicular to the axis of the cylindrical portion.