Patent Description:
An electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming system, and examples thereof include an electrophotographic copying machine, an electrophotographic printer (an LED printer, a laser beam printer, and the like), a facsimile apparatus, and a word processor.

In a so-called process cartridge-system image forming apparatus, a cartridge that is allowed or authorized to be attached to an apparatus body of an image forming apparatus may be attached to the apparatus body, and a cartridge that is not allowed or not authorized to be attached to the apparatus body may be attached to a cartridge attachment portion of the apparatus body of the image forming apparatus. This is an attachment error (insertion error) of a cartridge. A cartridge that is allowed to be attached to an apparatus body of an image forming apparatus is a cartridge of which the product model matches that of the image forming apparatus. Hereinafter, a cartridge that is allowed to be attached to the body of the image forming apparatus will be referred to as an allowed cartridge, and a cartridge that is not allowed to be attached to the body of the image forming apparatus will be referred to as an unallowed cartridge.

<CIT> proposes a method for preventing an attachment error of the unallowed cartridge. In this method, when an unallowed cartridge is inserted into an apparatus body of an image forming apparatus, a movable base provided near an opening of the apparatus body of the image forming apparatus cannot engage with a boss provided in the unallowed cartridge whereby an attachment error is prevented. That is, in the above-described configuration, an engagement portion is provided in the movable base so that the boss of an allowed cartridge engages with the movable base whereas the boss of an unallowed cartridge interferes with the movable base to prevent further insertion.

<CIT> proposes a method for identifying whether the cartridge is allowed one or not. In this method, when a cartridge is inserted into an apparatus body, after a first abutting portion of the cartridge passes through a protruding direction of a movable member of the apparatus body, when a second abutting portion abuts on an abutting target portion of the movable member, the first abutting portion and a rotary member of the apparatus body are separated from each other. Moreover, when the second abutting portion is separated from the movable member, the first abutting portion can pass through a protruding direction of the rotary member and the cartridge can be inserted into the apparatus body.

<CIT> discusses an image forming apparatus in which a cartridge including an erroneous attaching prevention unit and a protruding portion as a holding unit, can be inserted to an attached position. The image forming apparatus includes a frame, an inclined surface on which the protruding portion is placed, the inclined surface being provided to the frame, a guide portion defining with the inclined surface a gap through which the protruding portion is able to pass, and a movable member configured to engage with the erroneous attaching prevention unit on a downstream side of the guide portion in an insertion direction.

The present invention improves the conventional example and provides a technology capable of determining whether a cartridge is allowed to be attached to an image forming apparatus more reliably with a simple configuration.

The image forming apparatus according to the present invention is an image forming apparatus as specified in claims <NUM> to <NUM>.

According to the present invention, it is possible to determine whether a cartridge is allowed to be attached to an image forming apparatus more reliably with a simple configuration.

Hereinafter, a description will be given, with reference to the drawings, of embodiments (examples) of the present invention. However, the sizes, materials, shapes, their relative arrangements, or the like of constituents described in the embodiments may be appropriately changed according to the configurations, various conditions, or the like of apparatuses to which the invention is applied. Therefore, the sizes, materials, shapes, their relative arrangements, or the like of the constituents described in the embodiments do not intend to limit the scope of the invention to the following embodiments.

A cartridge and an image forming apparatus according to embodiments of the present invention will be described with reference to the drawings. Hereinafter, a laser beam printer will be described as an example of an image forming apparatus, and a cartridge used in a laser beam printer will be described as an example of a cartridge.

In the following description, it is assumed that a longitudinal direction of a cartridge matches a rotation axis direction of a photosensitive drum which is an image bearing member.

Moreover, reference numerals in the following description are used for reference to the drawings and do not limited the configuration.

The components integrated as a cartridge are designed appropriately depending on an apparatus configuration or the like and are not limited to those components of the cartridge illustrated herein.

<FIG> is a cross-sectional view of an image forming apparatus body A (hereinafter referred to as an "apparatus body A") of an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) according to Embodiment <NUM> of the present invention and a cartridge B as a first cartridge. <FIG> is a cross-sectional view of the cartridge B.

Here, the apparatus body A is a portion of a configuration of the image forming apparatus excluding the cartridge B.

The image forming apparatus illustrated in <FIG> is a laser beam printer which uses an electrophotographic technology and in which the cartridge B can be detachably attachable to the apparatus body A.

A sheet tray <NUM> that stacks a recording medium (a recording material) (hereinafter referred to as a "sheet PA") serving as an image forming target is disposed under the cartridge B.

Furthermore, a pickup roller 5a, a feed roller pair 5b, a transfer guide <NUM>, a transfer roller <NUM>, a conveying guide <NUM>, a fixing apparatus <NUM>, a discharge roller pair <NUM>, a discharge tray <NUM>, and the like are disposed in the apparatus body A sequentially along a conveying direction D of the sheet PA. The fixing apparatus <NUM> includes a heating roller 9a and a pressure roller 9b.

Next, an overview of an image forming process will be described. An electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum <NUM> or simply as a drum <NUM>) is rotated on the basis of a print start signal at a predetermined peripheral velocity (a process speed) in a direction indicated by arrow R in <FIG> and <FIG>.

A charging roller (a charging member) <NUM> to which a bias voltage is applied comes into contact with an outer circumference of the drum <NUM> to uniformly charge the outer circumference of the drum <NUM>.

An exposure apparatus <NUM> outputs a laser beam L corresponding to image information. The laser beam L passes through a laser opening <NUM> provided in a cleaning frame body <NUM> of the cartridge B to scan and expose the outer circumference of the drum <NUM>. In this way, an electrostatic latent image corresponding to the image information is formed on the outer circumference of the drum <NUM>.

On the other hand, as illustrated in <FIG>, in a developing unit <NUM> as a developing apparatus, toner T in a toner chamber <NUM> is stirred and conveyed by rotation of a conveying member (a stirring member) <NUM> and is delivered to a toner supply chamber <NUM>.

The toner T is borne on the surface of a developing roller (a developing sleeve) <NUM> by the magnetic force of a magnet roller (a stationary magnet) <NUM>. The developing roller <NUM> is a developer bearing member that bears a developer (toner T) on the surface thereof in order to develop the latent image formed on the drum <NUM>.

The thickness of the toner T on a circumferential surface of a developing roller <NUM> as a developer bearing member is regulated while being triboelectrically charged by a developing blade <NUM>.

The toner T is supplied to the drum <NUM> according to the electrostatic latent image to develop the latent image. In this way, the latent image becomes visible as a toner image (a developer image). The drum <NUM> is an image bearing member that bears the latent image or an image (a toner image or a developer image) formed by toner on the surface thereof. As illustrated in <FIG>, a sheet material PA stored in a lower part of the apparatus body A is delivered from the sheet tray <NUM> with the aid of the pickup roller 5a and the feed roller pair 5b in synchronization with an output timing of the laser beam L. The sheet material PA passes through the transfer guide <NUM> and is conveyed to a transfer position between the drum <NUM> and the transfer roller <NUM>. At this transfer position, the toner images are sequentially transferred from the drum <NUM> to the sheet material PA.

The sheet material PA to which the toner image is transferred is separated from the drum <NUM> and is conveyed to the fixing apparatus <NUM> along the conveying guide <NUM>. The sheet material PA passes through a nip portion between the heating roller 9a and the pressure roller 9b that form the fixing apparatus <NUM>. At this nip portion, a pressurizing and heating process is performed and the toner image is fixed to the sheet material PA. The sheet material PA to which the toner image is fixed is conveyed up to the discharge roller pair <NUM> and is discharged to the discharge tray <NUM>.

On the other hand, as illustrated in <FIG>, a residual toner on the outer circumference of the drum <NUM> after a transfer operation is performed is removed by the cleaning blade <NUM> and is used again for an image forming process. The toner removed from the drum <NUM> is stored in a waste toner chamber 71b of the cleaning unit <NUM>. The cleaning unit <NUM> is a unit having the photosensitive drum <NUM>.

The charging roller <NUM>, the developing roller <NUM>, the transfer roller <NUM>, and the cleaning blade <NUM> are process means acting on the drum <NUM>.

Next, an entire configuration of the cartridge B will be described with reference to <FIG>, <FIG>, and <FIG>. <FIG> is a schematic cross-sectional view of the cartridge B, and <FIG> and <FIG> are exploded perspective views for describing the configuration of the cartridge B. In the present embodiment, description of screws used for combining respective components will be omitted.

The cartridge B includes a cleaning unit (a photosensitive member holding unit, a drum holding unit, an image bearing member holding unit, or a first unit) <NUM>, a developing unit (a developer bearing member holding unit or a second unit) <NUM>.

In general, a process cartridge is a member in which an electrophotographic photosensitive member and at least one of the process means acting on the photosensitive member are integrated as a cartridge so as to be detachably attachable to a body (an apparatus body) of an electrophotographic image forming apparatus. Examples of process means include charging means, developing means, and cleaning means.

As illustrated in <FIG>, the cleaning unit <NUM> includes the drum <NUM>, the charging roller <NUM>, the cleaning member <NUM>, and the cleaning frame body <NUM> supporting these members.

As illustrated in <FIG>, on a driving side, the drum <NUM> is configured such that a driving-side drum flange <NUM> provided at a driving-side end of the drum <NUM> is rotatably supported by a hole 73a of a drum bearing <NUM>. In a broad sense, the drum bearing <NUM> and the cleaning frame body <NUM> can be also collectively referred to as a cleaning frame body.

As illustrated in <FIG>, on a non-driving side, the drum <NUM> is configured such that a drum shaft <NUM> press-fitted to a hole 71c formed in the cleaning frame body <NUM> is rotatably supported by a hole (not illustrated) of a non-driving-side drum shaft.

The drum flanges are bearing target portions that are rotatably supported by bearing portions.

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

The cleaning member <NUM> includes a rubber blade 77a which is a blade-shaped elastic member formed from rubber as an elastic member and a supporting member 77b supporting the rubber blade. The rubber blade 77a abuts on the drum <NUM> in a counter direction in relation to a rotation direction of the drum <NUM>. That is, the rubber blade 77a abuts on the drum <NUM> so that a distal end thereof faces the upstream side in the rotation direction of the drum <NUM>.

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

Moreover, as illustrated in <FIG>, a scooping sheet <NUM> for preventing the waste toner from leaking from the cleaning frame body <NUM> is provided at an edge of the cleaning frame body <NUM> so as to abut on the drum <NUM>.

The charging roller <NUM> is rotatably attached to the cleaning unit <NUM> with a charging roller bearing <NUM> at both ends in the longitudinal direction of the cleaning frame body <NUM>.

The longitudinal direction (the longitudinal direction of the cartridge B) of the cleaning frame body <NUM> is approximately parallel to an extension direction (an axial direction) of a rotation axis of the drum <NUM>. Therefore, hereinafter, a longitudinal direction or an axial direction means an axial direction of the drum <NUM> unless particularly stated.

The charging roller <NUM> is in pressure-contact with the drum <NUM> in such a way that a charging roller bearing <NUM> is pressed toward the drum <NUM> by a biasing member <NUM>. The charging roller <NUM> rotates following rotation of the drum <NUM>.

As illustrated in <FIG>, the developing unit <NUM> includes the developing roller <NUM>, a developing container <NUM> that supports the developing roller <NUM>, the developing blade <NUM>, and the like. The developing roller <NUM> is attached to the developing container <NUM> so as to be rotatably by bearing members <NUM> (<FIG>) and <FIG> (<FIG>) provided at both ends of the developing roller <NUM>.

Moreover, a magnet roller <NUM> is provided in the developing roller <NUM>. A developing blade <NUM> for regulating the toner layer on the developing roller <NUM> is disposed in the developing unit <NUM>. As illustrated in <FIG> and <FIG>, an interval holding member <NUM> is attached to both ends of the developing roller <NUM>, and the interval holding member <NUM> and the drum <NUM> abut on each other whereby the developing roller <NUM> is held with a very small gap formed between the drum <NUM> and the developing roller <NUM>.

Moreover, as illustrated in <FIG>, a blowoff prevention sheet <NUM> for preventing toner from leaking from the developing unit <NUM> is provided at an edge of a bottom member <NUM> so as to abut on the developing roller <NUM>. Furthermore, the conveying member <NUM> is provided in the toner chamber <NUM> formed by the developing container <NUM> and the bottom member <NUM>. The conveying member <NUM> stirs the toner stored in the toner chamber <NUM> and conveys the toner toward the toner supply chamber <NUM>.

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

When the developing unit and the cleaning unit are combined, first, the center of a first developing supporting boss 26a of the bearing member <NUM> with respect to a first driving-side suspension hole 71i of the cleaning frame body <NUM> is aligned to match the center of a second developing supporting boss 27a of the bearing member <NUM> with respect to a second non-driving-side suspension hole 71j. Specifically, the developing unit <NUM> is moved in a direction indicated by arrow G so that the first developing supporting boss 26a and the second developing supporting boss 27a are fitted to the first suspension hole 71i and the second suspension hole 71j, respectively. In this way, the developing unit <NUM> is connected so as to be movable in relation to the cleaning unit <NUM>. More specifically, the developing unit <NUM> is rotatably (turnably) connected to the cleaning unit <NUM>. That is, the developing roller <NUM> is connected so as to move toward and away from the drum <NUM>. After that, the drum bearing <NUM> is assembled with the cleaning unit <NUM> to form the cartridge B.

In the present embodiment, a non-driving-side biasing member <NUM> (<FIG>) and a non-driving-side biasing member 46R (<FIG>) are formed of a compression spring. By the biasing force of these springs, the driving-side biasing member <NUM> and the non-driving-side biasing member 46R biases the developing unit <NUM> toward the cleaning unit <NUM> whereby the developing roller <NUM> is reliably pressed toward the drum <NUM>. Furthermore, the interval holding member <NUM> is attached to both ends of the developing roller <NUM>. That is, the drum <NUM> and the developing roller <NUM> come into contact with each other with a predetermined contact pressure with the interval holding member <NUM> disposed therebetween whereby the developing roller <NUM> is held at a predetermined interval from the drum <NUM> and the relative positions thereof are determined.

Here, in order for the electrostatic latent image on the drum <NUM> to be stably developed with the toner T borne on the circumferential surface of the developing roller <NUM>, it is desirable that the interval between the drum <NUM> and the developing roller <NUM> is maintained constantly with high accuracy. In other words, it is required that a contact pressure when the drum <NUM> and the developing roller <NUM> come into contact with each other with the interval holding member <NUM> disposed therebetween is maintained stably.

Subsequently, attachment of the cartridge B will be described in detail with reference to <FIG>, <FIG>, <FIG>. <FIG> is a schematic cross-sectional view of a driving-side guide portion of the image forming apparatus A for describing attachment of the cartridge B, and <FIG> is a schematic cross-sectional view of a non-driving-side guide portion of the image forming apparatus A for describing attachment of the cartridge B. <FIG> is a schematic cross-sectional view on the driving side of the image forming apparatus A for describing positioning of the cartridge B. <FIG> is a schematic cross-sectional view on the non-driving side of the image forming apparatus A for describing positioning of the cartridge B. <FIG> is a schematic cross-sectional view of the driving-side guide portion of the image forming apparatus A for describing attachment of the cartridge B, and <FIG> is a schematic cross-sectional view of the non-driving-side guide portion of the image forming apparatus A for describing attachment of the cartridge B.

Attachment of the cartridge B will be described. As illustrated in <FIG>, a first driving-side plate <NUM> has an upper guide rail <NUM> and a guide rail <NUM> as a guide, and a driving-side plate <NUM> has a guide rail 16d and a guide rail 16e. Moreover, a drum bearing <NUM> provided on the driving side of the cartridge B has a rotation-stopping target portion 73c.

An attachment direction of the cartridge B is a direction (see arrow C) substantially orthogonal to an axial line of the drum <NUM>.

Moreover, the cleaning frame body <NUM> has a positioning target portion 71d and a rotation-stopping target portion <NUM> on the non-driving side in the longitudinal direction. When the cartridge B is attached from a cartridge insertion opening <NUM> of the apparatus body A, a boss <NUM> and a rotation-stopping target portion 73c of the cartridge B are guided to an upper guide rail <NUM> and a guide rail <NUM> of the apparatus body A on the driving side of the cartridge B. On the non-driving side of the cartridge B, a positioning target portion 71d and a rotation-stopping target portion <NUM> of the cartridge B are guided to a guide rail 16d and a guide rail 16e of the apparatus body A, respectively. In this way, the cartridge B is attached to the apparatus body A.

Next, a state in which a door <NUM> is closed will be described. As illustrated in <FIG>, <FIG>, the first driving-side plate <NUM> has an upper positioning portion 15a, a lower positioning portion 15b, an upper rotation-stopping portion 15c1, and a lower rotation-stopping portion 15c2 as a positioning portion. Moreover, the non-driving-side plate <NUM> has a positioning portion 16a, an upper rotation-stopping portion 16c1, and a lower rotation-stopping portion 16c2. The drum bearing <NUM> has an upper positioning target portion (a first positioning target portion, a first projection, or a first bulging portion) 73d and a lower positioning target portion (a second positioning target portion, a second projection, or a second bulging portion) 73f.

Moreover, cartridge pressing members <NUM> and <NUM> are rotatably attached to both ends in the axial direction of the door <NUM>. Cartridge pressing springs <NUM> and <NUM> are attached to both ends in the longitudinal direction of a front plate provided in the image forming apparatus A. The drum bearing <NUM> has a pressing target portion 73e as a biasing force receiving portion, and the cleaning frame body <NUM> has a pressing target portion 71o on the non-driving side (see <FIG> and <FIG> to <FIG>). When the door <NUM> is closed, the pressing target portions 73e and 71o of the cartridge B are pressed by the cartridge pressing members <NUM> and <NUM> biased by the cartridge pressing springs <NUM> and <NUM> of the apparatus body A (see <FIG>).

In this way, on the driving side, the upper positioning target portion 73d, the lower positioning target portion 73f, and the rotation-stopping target portion 73c of the cartridge B abut on the upper positioning portion 15a, the lower positioning portion 15b, and the rotation-stopping portion 15c of the apparatus body A, respectively. As a result, the cartridge B and the drum <NUM> are positioned on the driving side. Moreover, on the non-driving side, the positioning target portion 71d and the rotation-stopping target portion <NUM> of the cartridge B abut on the positioning portion 16a and the rotation-stopping portion 16c of the apparatus body A, respectively. In this way, the cartridge B and the drum <NUM> are positioned on the non-driving side.

While the above-described configuration has been described as an example of a configuration that determines the position of the cartridge B in relation to the apparatus body A, the configuration of the positioning means is not limited thereto. The positioning means may act directly on the upper positioning target portion 73d and the lower positioning target portion 73f on the driving side of the cartridge B and the positioning target portion 71d and the rotation-stopping target portion <NUM> on the non-driving side to fix the respective positioning portions.

A cartridge attachment error prevention mechanism (an attachment error prevention system) will be described by way of examples of the cartridge B as a first cartridge (an allowed or authorized cartridge) that is allowed or authorized to be attached to the apparatus body A and cartridges E1 and E2 as a second cartridge (an unallowed or unauthorized cartridge) that is not allowed or not authorized to be attached to the apparatus body A.

An operation of an attachment error prevention mechanism for the cartridge B will be described with reference to <FIG> and <FIG>.

<FIG> are lateral cross-sectional views illustrating a process of attaching the cartridge B to the apparatus body A. For the sake of convenience, only the non-driving-side plate <NUM> and the cleaning unit <NUM> are illustrated. Moreover, although only the cleaning unit <NUM> and a lever <NUM> are hatched in <FIG> so that the shapes of components are identified, the cleaning unit <NUM> and the lever <NUM> are not hatched in <FIG> for the sake of convenience.

<FIG> is a perspective view illustrating a state in which the cartridge B is attached to the apparatus body A, and <FIG> are detailed partial views illustrating a state in which the cartridge B is attached to the apparatus body A. In this example, for the sake of convenience, only the non-driving-side plate <NUM> is illustrated for the apparatus body A.

As illustrated in <FIG>, a rib 71p extending in a direction orthogonal to the longitudinal direction is provided at a non-driving-side end of the cleaning frame body <NUM>. A first engagement portion 71p1 is provided on the downstream side in a cartridge insertion direction (a direction indicated by arrow C) of the rib 71p.

Moreover, a guide rail 16f as a first guide portion is provided in the non-driving-side plate <NUM>. The guide rail 16f does not interfere with the rib 71p in the course of insertion of the cartridge B. However, as illustrated in <FIG>, when a cartridge E2 (a first unallowed cartridge) having a rib 71q (as an unallowed or unauthorized engagement portion) at a different position in the longitudinal direction from the rib 71p of the cartridge B is inserted, the rib 71q cannot pass through the guide rail 16f. That is, the guide rail 16f regulates insertion (arrival at an attachment completion position) of the cartridge E2.

That is, the guide rail 16f has an inlet shape corresponding to an outer shape of the rib 71p (a first engagement portion 71p1) when seen in a direction of attaching the cartridge to the apparatus body A, and a regulating wall abutting on the rib 1q is formed around the inlet. The guide rail 16f and the surrounding structure thereof form a first guide portion of the present invention. The first guide portion and the engagement portion (the rib 71p and the rib 71q) provided in the cartridge B and E2 form a first identifying portion for identifying whether a cartridge to be attached to the apparatus body A is allowed one or not.

As illustrated in <FIG>, a lever <NUM> as a movable member is provided in the non-driving-side plate <NUM>. The lever <NUM> is configured to be able to swing about a shaft center H. The lever <NUM> is biased in a direction indicated by arrow N1 by the biasing force applied from a biasing member (not illustrated), and a regulating target surface 16g1 of the lever <NUM> comes into contact with a regulating surface 16b provided in the non-driving-side plate <NUM> whereby the position of the lever <NUM> is determined. In this case, a state in which the lever <NUM> blocks a guiding path of the positioning target portion 71d of the guide rail 16d (a second guide portion) is created (this is a first position or a regulation position). In this way, an engagement target portion 16g2 provided in the lever <NUM> is configured to regulate a positioning target portion 71d2 of the cartridge E1 from advancing through the guide rail 16d in an attachment direction (a direction indicated by arrow C) as will be described later. As will be described in detail later, a movable member (the engagement target portion 16g2 of the lever <NUM>) at a regulation position and the positioning target portions 71d and 71d2 of a cartridge form a second identifying portion for identifying whether the cartridge that is to be attached to the apparatus body A is allowed one or not.

As illustrated in <FIG>, a surface 16g3 as an engagement target portion with which the first engagement portion 71p1 engages is provided in the lever <NUM>. The engagement target portion 16g2 and the surface 16g3 are provided closer to the downstream side in the cartridge insertion direction than the guide rail 16f.

When insertion of the cartridge B in the direction indicated by arrow C progresses, the first engagement portion 71p1 comes into contact with the surface 16g3 after passing through the guide rail 16f. In this case, the positioning target portion 71d is closer to the upstream side in the insertion direction (the direction indicated by arrow C) than the engagement target portion 16g2 of the lever <NUM>.

As illustrated in <FIG>, when insertion of the cartridge B in the direction indicated by arrow C progresses, the engagement target portion 16g3 receives force F1 from the first engagement portion 71p1 provided in the cartridge B by the insertion force of the cartridge B. In this way, the lever <NUM> moves in a direction indicated by arrow N2 about the shaft center H while resisting the biasing force from a biasing member (not illustrated). In this way, a state in which the lever <NUM> is completely released without blocking the guiding path of the positioning target portion 71d of the guide rail 16d is created (this is a second position or a non-regulation position). That is, a state in which the positioning target portion 71d of the cartridge B is allowed to proceed toward the guide rail 16d. In this case, the positioning target portion 71d is disposed closer to the upstream side in the insertion direction (the direction indicated by arrow C) than a place where the lever <NUM> was at the first position.

As illustrated in <FIG>, after insertion of the cartridge B progresses and the positioning target portion 71d passes through a place where the lever <NUM> is at the first position, the rib 71p having the first engagement portion 71p1 and the engagement target portion 16g3 maintain a contact state.

As illustrated in <FIG>, when insertion of the cartridge B progresses, the contact state between the rib 71p and the engagement target portion 16g3 disappears. In this way, the lever <NUM> receives force in a direction indicated by arrow N1 by the biasing force from a biasing member (not illustrated) to move up to the first position.

As described above, the lever <NUM> moves between the first position (the regulation position) and the second position (the non-regulation position) without making contact with the positioning target portion 71d in the course of inserting the cartridge B.

An operation of the attachment error prevention mechanism for the cartridge E1 (the second unallowed cartridge) will be with reference to <FIG>.

<FIG> is a lateral cross-sectional view illustrating a state in which the cartridge E1 is inserted into the apparatus body A. Similarly to <FIG>, only the non-driving-side plate <NUM> and the cleaning unit <NUM> are illustrated in <FIG>.

A difference between the cartridge E1 and the cartridge B is that the cartridge E1 does not have a shape corresponding to the first engagement portion 71p1. Due to this, when the cartridge E1 is inserted into the image forming apparatus, the cartridge E1 can proceed in the direction indicated by arrow C without interfering with the guide rail 16f However, the cartridge E1 does not have a shape corresponding to the first engagement portion 71p <NUM>. Due to this, even when insertion of the cartridge E1 progresses, the cartridge E1 does not come into contact with the surface 16g3 of the lever <NUM> and a force that moves the lever <NUM> up to the second position (the non-regulation position) is not applied. Therefore, the lever <NUM> remains blocking the guide rail 16d (this is, the second position). Due to this, when insertion of the cartridge E1 progresses, the positioning target portion 71d2 of the cartridge E1 as the second identifying portion comes into contact with the projection 16g4 provided in the engagement target portion 16g2 of the lever <NUM>. In this case, a force F2 from the positioning target portion 71d2 is applied to the projection 16g4 by the attachment force of the cartridge E1.

The projection 16g4 is configured to abut on the positioning target portion 71d2 so that a force acting in a direction of resisting the biasing force acting on the lever <NUM> is not generated from the force F2 received from the positioning target portion 71d2 of the cartridge E1 (so that the force F2 does not include such a component force). At least the force F2 that the projection 16g4 receives from the positioning target portion 71d2 may act in the direction orthogonal to the movable direction of the engagement target portion 16g2 of the lever <NUM>. Preferably, the projection 16g4 may be pressed from the positioning target portion 71d2 at such an angle that a force acting in a direction (a direction opposite to the direction toward the non-regulation position) along the turning direction of the lever <NUM> due to the biasing force is generated.

Here, a regulating surface <NUM> as a supporting portion that supports the lever <NUM> is provided in the non-driving-side plate <NUM> on a side (the downstream side in the insertion direction (the direction indicated by arrow C)) of the lever <NUM> opposite the engagement target portion 16g2 pressed from the positioning target portion 71d2. In this way, for example, even when the cartridge E1 is forcibly inserted, the lever <NUM> receives the force F2 from the positioning target portion 71d, and the lever <NUM> is deformed, deformation of the lever <NUM> in the direction of the force F2 can be regulated by the regulating surface <NUM>. Due to this, it is possible to prevent deformation and destruction of the lever <NUM> and to regulate insertion (arrival at an attachment completion position) of an unallowed cartridge reliably.

In the present embodiment, although the positioning target portions 71d and 71d2 on the non-driving side of the cartridge are used as the second identifying portion in order to save the space, the present invention is not limited to the configuration, but another configuration portion may be used and another configuration dedicated for the identifying portion may be provided.

Next, an operation of removing the cartridge B will be described with reference to <FIG>.

As described above, when the cartridge B is in an attachment completion state, the lever <NUM> is at the first position.

A second engagement portion 71p2 is provided on the upstream side in the insertion direction (the direction indicated by arrow C) of the rib 71p of the cartridge B. When the cartridge B is moved in a direction opposite to the direction indicated by arrow C, the second engagement portion 71p2 comes into contact with the surface 16g3 before the positioning target portion 71d comes into contact with the lever <NUM>. A force F3 is applied to the lever <NUM> with the second engagement portion 71p2 disposed therebetween by a removal force of the cartridge B. In this way, the lever <NUM> rotates about the shaft center H in the direction N2 and moves from the first position to the second position. A subsequent removal opening is reverse to the above-described attachment operation of the cartridge B, and the description thereof will be omitted.

As described above, according to the present embodiment, it is possible to determine whether a cartridge is allowed to be attached to an image forming apparatus reliably with a simple configuration without any adverse influence on an attachment/detachment operation of an allowed cartridge.

A cartridge and an image forming apparatus according to Embodiment <NUM> of the present invention will be described with reference to the drawings.

In the following description, the components of Embodiment <NUM> the same as those of Embodiment <NUM> will be denoted by the same reference numerals. Moreover, it is assumed that a longitudinal direction Y as a first direction matches a rotation axis direction of a photosensitive drum which is an image bearing member. Moreover, in the longitudinal direction Y, a side to which a driving force is transmitted from an apparatus body of the image forming apparatus to the photosensitive drum will be referred to as a driving side, and the opposite side will be referred to as a non-driving side.

<FIG> is a cross-sectional view of an image forming apparatus body 2A (hereinafter referred to as an "apparatus body 2A") of an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) according to Embodiment <NUM> of the present invention and a cartridge 2B as a first cartridge. <FIG> is a cross-sectional view of the cartridge 2B.

Here, the apparatus body 2A is a portion of a configuration of the image forming apparatus excluding the cartridge 2B.

The image forming apparatus illustrated in <FIG> is a laser beam printer which uses an electrophotographic technology and in which the cartridge 2B can be detachably attachable to the apparatus body 2A.

A sheet tray <NUM> that stacks a recording medium (a recording material) (hereinafter referred to as a "sheet P") serving as an image forming target is disposed under the cartridge 2B.

Furthermore, a pickup roller 5a, a feed roller pair 5b, a transfer guide <NUM>, a transfer roller <NUM>, a conveying guide <NUM>, a fixing apparatus <NUM>, a discharge roller pair <NUM>, a discharge tray <NUM>, and the like are disposed in the apparatus body 2A sequentially along a conveying direction D of the sheet P. The fixing apparatus <NUM> includes a heating roller 9a and a pressure roller 9b.

An exposure apparatus <NUM> outputs a laser beam L corresponding to image information. The laser beam L passes through a laser opening <NUM> provided in a cleaning frame body <NUM> of the cartridge 2B to scan and expose the outer circumference of the drum <NUM>. In this way, an electrostatic latent image corresponding to the image information is formed on the outer circumference of the drum <NUM>.

The toner T is supplied to the drum <NUM> according to the electrostatic latent image to develop the latent image. In this way, the latent image becomes visible as a toner image (a developer image). The drum <NUM> is an image bearing member that bears the latent image or an image (a toner image or a developer image) formed by toner on the surface thereof. As illustrated in <FIG>, a sheet material P stored in a lower part of the apparatus body 2A is delivered from the sheet tray <NUM> with the aid of the pickup roller 5a and the feed roller pair 5b in synchronization with an output timing of the laser beam L. The sheet material P passes through the transfer guide <NUM> and is conveyed to a transfer position between the drum <NUM> and the transfer roller <NUM>. At this transfer position, the toner images are sequentially transferred from the drum <NUM> to the sheet material P.

The sheet material P to which the toner image is transferred is separated from the drum <NUM> and is conveyed to the fixing apparatus <NUM> along the conveying guide <NUM>. The sheet material P passes through a nip portion between the heating roller 9a and the pressure roller 9b that form the fixing apparatus <NUM>. At this nip portion, a pressurizing and heating process is performed and the toner image is fixed to the sheet material P. The sheet material P to which the toner image is fixed is conveyed up to the discharge roller pair <NUM> and is discharged to the discharge tray <NUM>.

On the other hand, as illustrated in <FIG>, a residual toner on the outer circumference of the drum <NUM> after a transfer operation is performed is removed by the cleaning blade <NUM> and is used again for an image forming process. The toner removed from the drum <NUM> is stored in a waste toner chamber 271b of the cleaning unit <NUM>. The cleaning unit <NUM> is a unit having the photosensitive drum <NUM>.

Next, an entire configuration of the cartridge 2B will be described with reference to <FIG>, <FIG>, and <FIG>. <FIG> is a schematic cross-sectional view of the cartridge 2B, and <FIG> and <FIG> are exploded perspective views for describing the configuration of the cartridge 2B. In the present embodiment, description of screws used for combining respective components will be omitted.

The cartridge 2B includes a cleaning unit (a photosensitive member holding unit, a drum holding unit, an image bearing member holding unit, or a first unit) <NUM>, a developing unit (a developer bearing member holding unit or a second unit) <NUM>.

As illustrated in <FIG>, on a driving side as the other end side, the drum <NUM> is configured such that a driving-side drum flange <NUM> provided at a driving-side end of the drum <NUM> is rotatably supported by a hole 273a of a drum bearing <NUM>. In a broad sense, the drum bearing <NUM> and the cleaning frame body <NUM> can be also collectively referred to as a cleaning frame body.

As illustrated in <FIG>, on a non-driving side as one end side, the drum <NUM> is configured such that a drum shaft <NUM> press-fitted to a hole 271c formed in the cleaning frame body <NUM> is rotatably supported by a hole (not illustrated) of a non-driving-side drum shaft.

The cleaning member <NUM> includes a rubber blade 277a which is a blade-shaped elastic member formed from rubber as an elastic member and a supporting member 277b supporting the rubber blade. The rubber blade 277a abuts on the drum <NUM> in a counter direction in relation to a rotation direction of the drum <NUM>. That is, the rubber blade 277a abuts on the drum <NUM> so that a distal end thereof faces the upstream side in the rotation direction of the drum <NUM>.

As illustrated in <FIG>, the waste toner removed from the surface of the drum <NUM> by the cleaning member <NUM> is stored in a waste toner chamber 271b formed by the cleaning frame body <NUM> and the cleaning member <NUM>.

As illustrated in <FIG>, the developing unit <NUM> includes the developing roller <NUM>, a developing container <NUM> that supports the developing roller <NUM>, the developing blade <NUM>, and the like. The developing roller <NUM> is attached to the developing container <NUM> so as to be rotatably by bearing members <NUM> (<FIG>) and <NUM> (<FIG>) provided at both ends of the developing roller <NUM>.

Moreover, as illustrated in <FIG>, a developing sheet member <NUM> for preventing toner from leaking from the developing unit <NUM> is provided at an edge of a bottom member <NUM> so as to abut on the developing roller <NUM>. Furthermore, the conveying member <NUM> is provided in the toner chamber <NUM> formed by the developing container <NUM> and the bottom member <NUM>. The conveying member <NUM> stirs the toner stored in the toner chamber <NUM> and conveys the toner toward the toner supply chamber <NUM>.

As illustrated in <FIG> and <FIG>, the cartridge 2B is formed by combining the cleaning unit <NUM> and the developing unit <NUM>.

When the developing unit and the cleaning unit are combined, first, the center of a first developing supporting boss 226a of the bearing member <NUM> with respect to a first driving-side suspension hole 271i of the cleaning frame body <NUM> is aligned to match the center of a second developing supporting boss 227a of the bearing member <NUM> with respect to a second non-driving-side suspension hole 271j. Specifically, the developing unit <NUM> is moved in a direction indicated by arrow G so that the first developing supporting boss 226a and the second developing supporting boss 227a are fitted to the first suspension hole 271i and the second suspension hole 271j, respectively. In this way, the developing unit <NUM> is connected so as to be movable in relation to the cleaning unit <NUM>. More specifically, the developing unit <NUM> is rotatably (turnably) connected to the cleaning unit <NUM>. That is, the developing roller <NUM> is connected so as to move toward and away from the drum <NUM>. After that, the drum bearing <NUM> is assembled with the cleaning unit <NUM> to form the cartridge 2B.

In the present embodiment, a non-driving-side biasing member <NUM> (<FIG>) and a non-driving-side biasing member 246R (<FIG>) are formed of a compression spring. By the biasing force of these springs, the driving-side biasing member <NUM> and the non-driving-side biasing member 246R biases the developing unit <NUM> toward the cleaning unit <NUM> whereby the developing roller <NUM> is reliably pressed toward the drum <NUM>. Furthermore, the interval holding member <NUM> is attached to both ends of the developing roller <NUM>. That is, the drum <NUM> and the developing roller <NUM> come into contact with each other with a predetermined contact pressure with the interval holding member <NUM> disposed therebetween whereby the developing roller <NUM> is held at a predetermined interval from the drum <NUM> and the relative positions thereof are determined.

Next, attachment of the cartridge 2B to the apparatus body 2A will be described in detail with reference to <FIG>, <FIG>, <FIG>.

<FIG> are explanatory diagrams (schematic cross-sectional views) illustrating an attachment portion of the apparatus body 2A to the cartridge 2B, in which <FIG> and <FIG> illustrate a non-driving side and <FIG> and <FIG> illustrate a driving side. <FIG> are diagrams when the cartridge 2B is attached to the apparatus body 2A and are diagrams when seen from a side closer to a downstream side than the upstream side in the attachment direction C of the cartridge 2B.

As illustrated in <FIG>, the door <NUM> for exposing and covering an attachment portion S of the cartridge 2B is provided in the apparatus body 2A. When the cartridge 2B is attached, the door <NUM> is turned in a direction indicated by arrow R1 so that the attachment portion S of the cartridge 2B and an insertion opening <NUM> which is formed in the attachment portion S and is an inlet used for attaching the cartridge 2B are exposed. In this way, a state in which the cartridge 2B can be attached to the apparatus body 2A in a direction (the attachment direction C) orthogonal to the longitudinal direction Y.

As illustrated in <FIG>, <FIG>, a non-driving-side guide <NUM> is provided on the non-driving side of the attachment portion S. The non-driving-side guide <NUM> has a non-driving-side upper guide 216d notched along the attachment direction C, a non-driving-side lower guide 216e, and a non-driving-side inner surface <NUM> opposing (facing) the attachment portion S.

On the other hand, as illustrated in <FIG>, <FIG>, a driving-side guide <NUM> and a second guide rail <NUM> (a second guide portion) as a second identifying portion are provided on the driving side of the attachment portion S. The driving-side guide <NUM> and the second guide rail <NUM> have a driving-side guide portion 215d and a second guide portion 218a notched along the attachment direction C, respectively. Moreover, the second guide rail <NUM> further has a driving-side inner surface 218c opposing (facing) the attachment portion S.

On the other hand, a guiding target portion along which attachment to the apparatus body 2A is guided is provided in the cartridge 2B.

As illustrated in <FIG> and <FIG>, on the non-driving side of the cartridge 2B, an end surface <NUM> orthogonal to the longitudinal direction Y, a positioning target portion 271d (a third projection) as a third identification target portion protruding toward the outer side in the longitudinal direction Y from the end surface <NUM>, and a rotation-stopping target portion <NUM> are provided in the cleaning frame body <NUM>.

As illustrated in <FIG> and <FIG>, on the driving side of the cartridge 2B, an end surface <NUM> orthogonal to the longitudinal direction Y, a rotation-stopping target portion 273c (a first projection) protruding toward the outer side in the longitudinal direction Y from the end surface <NUM>, and an identification target boss <NUM> (a second projection) as a second identification target portion are provided in the drum bearing <NUM>.

As illustrated in <FIG>, when the cartridge 2B is attached from the cartridge insertion opening <NUM> of the apparatus body 2A, the non-driving-side end surface <NUM> and the driving-side end surface <NUM> of the cartridge 2B approach and face the non-driving-side inner surface <NUM> and the driving-side inner surface 218c, respectively. In this way, the position (trajectory) in the longitudinal direction Y during attachment of the cartridge 2B is determined.

Moreover, on the non-driving side of the cartridge 2B, the positioning target portion 271d is guided to the non-driving-side upper guide 216d and the rotation-stopping target portion <NUM> is guided to the non-driving-side lower guide 216e.

In contrast, on the driving side of the cartridge 2B, the identification target boss <NUM> is guided to the second guide portion 218a and the rotation-stopping target portion 273c is guided to the driving-side guide portion 215d.

In this way, the position (trajectory) in the direction (an up-down direction Z) orthogonal to the attachment direction C and the longitudinal direction Y of the cartridge 2B during attachment of the cartridge 2B is determined.

In this manner, the cartridge 2B is attached to the apparatus body 2A along the determined attachment trajectory (the attachment direction C).

Next, a state in which a door <NUM> is closed will be described. As illustrated in <FIG>, <FIG>, the driving-side guide <NUM> has an upper positioning portion 215a, a lower positioning portion 215b, and a rotation-stopping portion 215c as a positioning portion. Moreover, the non-driving-side guide <NUM> has a positioning portion 216a and a rotation-stopping portion 216c. The drum bearing <NUM> has an upper positioning target portion 273d and a lower positioning target portion 273f.

Moreover, cartridge pressing members <NUM> and <NUM> are rotatably attached to both ends in the axial direction of the door <NUM>. The cartridge pressing springs <NUM>, <NUM> are attached to both ends in the longitudinal direction Y of a front plate provided in the apparatus body 2A. The drum bearing <NUM> has a pressing target portion 273e as a biasing force receiving portion and the cleaning frame body <NUM> has a pressing target portion 271o on the non-driving side (see <FIG>, <FIG>, <FIG>, <FIG>). When the door <NUM> is closed, the pressing target portions 273e and 271o of the cartridge 2B are pressed by the cartridge pressing members <NUM> and <NUM> biased by the cartridge pressing springs <NUM> and <NUM> of the apparatus body 2A (see <FIG>).

In this way, on the driving side, the upper positioning target portion 273d, the lower positioning target portion 273f, and the rotation-stopping target portion 273c of the cartridge 2B abut on the upper positioning portion 215a, the lower positioning portion 215b, and the rotation-stopping portion 215c of the , respectively. As a result, the cartridge 2B and the drum <NUM> are positioned on the driving side. Moreover, on the non-driving side, the positioning target portion 271d and the rotation-stopping target portion <NUM> of the cartridge 2B abut on the positioning portion 216a and the rotation-stopping portion 216c of the apparatus body 2A, respectively. In this way, the cartridge 2B and the drum <NUM> are positioned on the non-driving side.

While the above-described configuration has been described as an example of a configuration that determines the position of the cartridge 2B in relation to the apparatus body 2A, the configuration of the positioning means is not limited thereto. The positioning means may act directly on the positioning target portion 271d and the rotation-stopping target portion <NUM> on the driving side of the cartridge 2B and the positioning target portion 273d and the rotation-stopping target portion 273f on the non-driving side to fix the respective positioning portions.

A cartridge attachment error prevention system according to the present embodiment will be described with reference to <FIG> and <FIG>.

An overview of a cartridge attachment error prevention system will be described with reference to <FIG>. As illustrated in <FIG>, the cartridge attachment error prevention system includes a first attachment error prevention mechanism provided on one end side (the non-driving side) in the longitudinal direction Y and a second attachment error prevention mechanism provided on the other end side (the driving side). The first attachment error prevention mechanism and the second attachment error prevention mechanism function independently, and a cartridge being allowed by both mechanisms can be attached to the apparatus body 2A (the details will be described later).

A configuration of the first cartridge attachment error prevention mechanism will be described with reference to <FIG> is an explanatory diagram of the apparatus body 2A and the cartridge 2B related to the first attachment error prevention mechanism, and <FIG> is an explanatory diagram of the apparatus body 2A and the cartridge 2B.

As illustrated in <FIG>, a rib 271p as a first identification target portion, extending in a direction (the up-down direction Z) orthogonal to both the longitudinal direction Y and the attachment direction C is provided at a non-driving-side end of the cleaning frame body <NUM>. A first abutting portion 271p1 is provided on the upstream side in the cartridge attachment direction C of the rib 271p. Meanwhile, as illustrated in <FIG>, a non-driving-side identification rail 216f as a first identifying portion is provided in the apparatus body 2A. A notch 216f1 (a first guide portion) is provided in the non-driving-side identification rail 216f at a position matching the rib 271p in the longitudinal direction Y of the cartridge 2B.

Moreover, as illustrated in <FIG>, a movable lever <NUM> as a first movable member is provided in the non-driving-side guide <NUM>. The movable lever <NUM> is configured to be swingable about the shaft center H and is biased in the direction indicated by arrow N1 by a biasing member (not illustrated). The position of the movable lever <NUM> is determined in such a way that the regulating target surface 216g1 of the movable lever <NUM> comes into contact with the regulating surface 216b provided on the non-driving-side plate <NUM> (this is the first regulation position). In this case, a state in which the movable lever <NUM> blocks an attachment path (a guiding path) G1 of the positioning target portion 271d of the cartridge 2B by the non-driving-side upper guide 216d (a third guide portion) is created. Moreover, an abutting surface 216g3 is provided in the movable lever <NUM> on a side closer to the downstream side in the attachment direction C of the cartridge 2B than the notch 216f1. At the first regulation position, the abutting surface 216g3 is a surface that crosses the attachment direction C and the direction (a tangential direction of a circle about the shaft center H) indicated by arrow N1 of the cartridge 2B and faces the direction indicated by arrow N1. Furthermore, a lever regulating portion 216g2 as a first movable portion is provided in the vicinity of the regulating target surface 216g1 of the movable lever <NUM>. At the first regulation position, the lever regulating portion 216g2 is a surface that crosses the attachment direction C of the cartridge 2B and faces the direction indicated by arrow N3.

A process in which the cartridge 2B that is allowed to be attached to the apparatus body 2A is attached to the first attachment error prevention mechanism on the non-driving side will be described with reference to <FIG> are lateral cross-sectional views illustrating a process in which the cartridge 2B is attached to the apparatus body 2A. For the sake of convenience, only the non-driving-side guide <NUM> and the cleaning unit <NUM> are illustrated. Moreover, although only the cleaning unit <NUM> and the movable lever <NUM> are hatched in <FIG> so that the shapes of components are identified, no component is hatched in <FIG> for the sake of convenience.

As illustrated in <FIG>, when the cartridge 2B is inserted into the apparatus body 2A, the rib 271p passes through the notch 216f and enters the apparatus body 2A. Subsequently, when the cartridge 2B enters the apparatus body 2A, the first abutting portion 271p1 of the rib 271p abuts on the abutting surface 216g3 of the movable lever <NUM> before the positioning target portion 271d abuts on the lever regulating portion 216g2.

When the cartridge 2B is inserted further in the direction C in this state, as illustrated in <FIG>, the first abutting portion 271p1 applies a force F1 originating from the attachment force (the operating force of a user) of the cartridge 2B to the abutting surface 216g3. With this force F1, the movable lever <NUM> is turned in the direction indicated by arrow N2 and the cartridge 2B can enter further into the apparatus body 2A. Moreover, in this case, with turning of the movable lever <NUM>, the lever regulating portion 216g2 also moves in the direction indicated by arrow N2 up to a first allowable position (a non-regulation position) at which the attachment path G1 (see <FIG>) of the positioning target portion 271d of the cartridge 2B is released.

Furthermore, when insertion of the cartridge 2B progresses, as illustrated in <FIG>, the positioning target portion 271d passes through the lever regulating portion 216g2 in a state in which the rib 271p and the abutting surface 216g3 are in contact with each other. When the rib 271p passes through the abutting surface 216g3, the cartridge 2B can be finally reached to an attachment completion position with respect to the apparatus body 2A, at which as described above, the positioning target portion 271d and the rotation-stopping target portion <NUM> illustrated in <FIG> abut on the positioning portion 216a and the rotation-stopping portion 216c of the apparatus body 2A, respectively.

In this case, since the rib 271p does not abut on the abutting surface 216g3, as illustrated in <FIG>, the movable lever <NUM> is moved again to the first regulation position by a biasing force.

In this manner, when the cartridge 2B that is allowed to be attached to the apparatus body 2A is inserted, the rib 271p passes through the notch 216f1 to turn the movable lever <NUM>. In this way, the cartridge 2B can enter the apparatus body 2A while preventing the positioning target portion 271d from abutting on the lever regulating portion 216g2.

A process in which the first attachment error prevention mechanism prevents an attachment error of a cartridge D1 (a first unallowed cartridge) to the apparatus body 2A will be described with reference to <FIG>. As illustrated in <FIG>, the cartridge D1 has a rib 271q (as an unallowed identification target portion) at a different position in the longitudinal direction Y from the rib 271p of the cartridge 2B. When the cartridge D1 is to be inserted, since the position in the longitudinal direction of the rib 271q is different from that of the notch 216f1 of the non-driving-side identification rail 216f, the cartridge D1 cannot pass through the non-driving-side identification rail 216f. In this way, attachment of the cartridge D1 can be regulated.

That is, the notch 216f1 of the non-driving-side identification rail 216f has an inlet shape corresponding to an outer shape of the rib 271p of the cartridge 2B when seen in the attachment direction to the apparatus body 2A of the cartridge. A regulating wall abutting on the rib 271q of the cartridge D2 is formed around the inlet. First identification of whether the cartridge to be attached to the apparatus body 2A is allowed one or not is realized by the non-driving-side identification rail 216f as the first identifying portion and the ribs 271p and 271q as the first identification target portion provided in the cartridge 2B or D1.

A process of preventing an attachment error of still another cartridge D2 (a second unallowed cartridge) will be described with reference to <FIG> is a lateral cross-sectional view illustrating a state in which the cartridge D2 is attached to the apparatus body 2A. Similarly to <FIG>, only the non-driving-side guide <NUM> and the cleaning unit <NUM> are illustrated.

As illustrated in <FIG>, the cartridge D2 does not have the rib 271p of the cartridge 2B. Due to this, the cartridge D2 can proceed in the attachment direction C while preventing the cleaning frame body <NUM> from interfering with the non-driving-side identification rail 216f. However, if the cartridge D2 is inserted in this state, the cartridge D2 proceeds while the cleaning frame body <NUM> does not abut on the abutting surface 216g3. By doing so, in a state in which the movable lever <NUM> is at the first regulation position, the positioning target portion 271d2 as a third identification target portion of the cartridge D2 comes into contact with the lever regulating portion 216g2. In this way, a force F2 originating from the attachment force of the cartridge D2 is applied to the lever regulating portion 216g2 from the positioning target portion 271d2.

Since the lever regulating portion 216g2 faces in the direction indicated by arrow N3, the force F2 acts in such a way as to turn the movable lever <NUM> in the direction indicated by arrow N1. By doing so, the movable lever <NUM> cannot move further and the attachment path G1 remains in a blocked state. In this way, it is possible to regulate attachment of the cartridge D2.

That is, third identification of whether the cartridge to be attached to the apparatus body 2A is allowed one or not is realized by the lever regulating portion 216g2 of the movable lever <NUM> as the third identifying portion and the positioning target portion 271d2 of the cartridge D2 as the third identification target portion.

More specifically, a projection 216g4 is provided at a distal end in the direction indicated by arrow N1 of the lever regulating portion 216g2, and the lever regulating portion 216g2 comes into contact with mainly the positioning target portion 271d2 of the cartridge D2 of the projection 216g4. The projection 216g4 is configured to abut on the positioning target portion 271d2 so that a force acting in the direction of resisting the biasing force acting on the movable lever <NUM> is not generated from the force F2 received from the positioning target portion 271d2 (so that the force F2 does not include such a component force). At least the force F2 that the projection 216g4 receives from the positioning target portion 271d2 may act in the direction orthogonal to the movable direction (the directions indicated by arrows N1 and N2) of the lever regulating portion 216g2 of the movable lever <NUM>. Preferably, the projection 216g4 may be pressed from the positioning target portion 271d2 at such an angle that a force acting in a direction (a direction opposite to the direction toward the non-regulation position) along the turning direction of the movable lever <NUM> due to the biasing force is generated.

Here, a regulating surface <NUM> as a supporting portion that supports the movable lever <NUM> is provided in the non-driving-side guide <NUM> on a side (the downstream side in the insertion direction (the direction indicated by arrow C)) of the movable lever <NUM> opposite the lever regulating portion 216g2 pressed from the positioning target portion 271d2. In this way, for example, even when the cartridge D2 is forcibly inserted, the movable lever <NUM> receives the force F2 from the positioning target portion 271d, and the movable lever <NUM> is deformed, deformation of the movable lever <NUM> in the direction of the force F2 can be regulated by the regulating surface <NUM>. Due to this, it is possible to prevent deformation and destruction of the movable lever <NUM> and to regulate insertion (arrival at an attachment completion position) of an unallowed cartridge reliably.

As described above, using the first attachment error prevention mechanism provided on one end side (a non-driving side) of a cartridge, it is possible to allow attachment of an allowed cartridge and regulate attachment of an unallowed cartridge (a first or second unallowed cartridge).

An operation when the cartridge 2B is removed will be described with reference to <FIG>.

As described above, the movable lever <NUM> is at the first regulation position when the cartridge 2B is in an attachment completion state.

A second abutting portion 271p2 is provided on the upstream side in the insertion direction (the direction indicated by arrow C) of the rib 271p of the cartridge 2B. When the cartridge 2B is moved in a direction opposite to the direction indicated by arrow C, the second abutting portion 271p2 comes into contact with the abutting surface 216g3 before the positioning target portion 271d comes into contact with the movable lever <NUM>. A force F3 is applied to the movable lever <NUM> with the second abutting portion 271p2 disposed therebetween by a removal force of the cartridge 2B. In this way, the movable lever <NUM> rotates about the shaft center H in the direction indicated by arrow N2 and moves from the first regulation position to the first allowable position. A subsequent removal opening is reverse to the above-described attachment operation of the cartridge 2B, and the description thereof will be omitted.

A second cartridge attachment error prevention mechanism provided on the driving side of the apparatus body 2A will be described with reference to <FIG>. <FIG> is an explanatory diagram of the second attachment error prevention mechanism of the cartridge 2B and <FIG> is an explanatory diagram of the second attachment error prevention mechanism of the apparatus body 2A. <FIG> are explanatory diagrams of the second attachment error prevention mechanism of the apparatus body 2A, in which some mechanisms are taken out.

As illustrated in <FIG>, on the driving side in the longitudinal direction Y of the cartridge 2B, an abutting target portion 273f as a fourth identification target portion is provided in addition to the identification target boss <NUM> (the second identification target portion) and the rotation-stopping target portion 273c. The abutting target portion 273f is a portion provided integrally with a downstream-side end in the attachment direction C of the end surface <NUM> of the drum bearing <NUM> and has a surface vertical to the attachment direction C. The abutting target portion 273f passes through a place near a driving-side inner surface 218c illustrated in <FIG> similarly to the driving-side end surface <NUM> during attachment of the cartridge 2B. Here, as illustrated in <FIG>, a distance in the up-down direction Z between the identification target boss <NUM> and the rotation-stopping target portion 273c is defined as a distance 73r, and a path through which the abutting target portion 273f passes is defined as an attachment trajectory G2 (a fourth guide portion) (see <FIG>).

On the other hand, as illustrated in <FIG>, a movable slider <NUM> and a movable cam <NUM> as a second movable member are provided on the driving side of the apparatus body 2A in addition to the driving-side guide <NUM> and the second guide rail <NUM> (the second identifying portion). As described above, the driving-side guide portion 215d is provided in the driving-side guide <NUM>, and the second guide portion 218a is provided in the second guide rail <NUM>. An interval between these guide portions in the up-down direction Z is defined as a distance 15r.

The movable slider <NUM> is supported by the second guide rail <NUM> and is provided so as to be movable in the up-down direction Z of the cartridge 2B. The movable slider <NUM> is biased in a direction indicated by arrow M1 by a slider spring <NUM> which is a compression spring so as to block the second guide portion 218a. Moreover, the movable slider <NUM> has an abutting surface 240a on the upstream side in the attachment direction C of the cartridge 2B so as to intersect the attachment direction C and the direction indicated by arrow M1 and face the upstream side in the attachment direction C. Furthermore, as illustrated in <FIG>, the movable slider <NUM> has a connecting portion 240b that operates the movable cam <NUM> on the downstream side in the attachment direction C of the cartridge 2B.

The movable cam <NUM> is supported by the second guide rail <NUM> (see <FIG>) on a side closer to the downstream side than the movable slider <NUM> in the attachment direction C of the cartridge 2B. As illustrated in <FIG>, the movable cam <NUM> includes a cam regulating portion 241a as a second movable portion (a fourth identifying portion), a supporting target portion 241c supported by the second guide rail <NUM> (see <FIG>), and a connecting target portion 241b that receives an operating force from the movable slider <NUM>. The movable cam <NUM> is supported so as to be able to turn about the supporting target portion 241c in a direction parallel to the attachment direction C and is movable between the second regulation position (<FIG>) and the second allowable position (<FIG>). Here, when the movable cam <NUM> is at the second regulation position, as illustrated in <FIG>, the cam regulating portion 241a protrudes further from the driving-side inner surface 218c to block the attachment path G2 of the abutting target portion 273f. In contrast, as illustrated in <FIG>, when the movable cam <NUM> is at the second allowable position (the non-regulation position), the cam regulating portion 241a does not protrude further from the driving-side inner surface 218c to release the attachment path G2 of the abutting target portion 273f. Furthermore, the movable cam <NUM> is biased by a cam spring <NUM> which is a torsion coil spring in the direction indicated by arrow Q2 (that is, so as to be at the second allowable position).

As illustrated in <FIG>, in a natural state in which an external force is not applied, the movable slider <NUM> moves in the direction indicated by arrow M1 by the biasing force of a slider spring <NUM>. By doing so, the connecting portion 240b presses the connecting target portion 241b in the direction indicated by arrow M1, whereby the movable cam <NUM> turns in the direction indicated by arrow Q1 while resisting against the biasing force of the cam spring <NUM>. The movement in the direction M1 of the movable slider <NUM> is regulated when a boss 215e provided in the driving-side guide <NUM> fits into a guide 240c provided in the movable slider <NUM> to abut on a guide upper surface 240c1. The connecting portion 240b and the connecting target portion 241b are interlocked with each other whereby the positions of the movable cam <NUM> and the cam regulating portion 241a are determined (the second regulation position).

In contrast, as illustrated in <FIG>, when the movable slider <NUM> is moved in a direction (the direction indicated by arrow M2) opposite to the direction indicated by arrow M1 by an external force, the connecting portion 240b is separated from the connecting target portion 241b of the movable cam <NUM>. By doing so, the movable cam <NUM> turns in the direction (the direction indicated by arrow Q2) opposite to the direction indicated by arrow Q1 by the biasing force of the cam spring <NUM> until the connecting target portion 241b abuts on the connecting portion 240b.

Furthermore, when the movable cam <NUM> turns in the direction indicated by arrow Q2 by an external force, the movable slider <NUM> moves in the direction indicated by arrow M2 while resisting the biasing force of the slider spring <NUM>. In this way, even when the direction of operation and the master-slave relation are reversed, these components are interlocked with each other similarly.

Although a spring (biasing means) is provided in both the movable slider <NUM> and the movable cam <NUM>, the biasing means may be provided in either one of them and the movable slider <NUM> and the movable cam <NUM> may be connected by a link mechanism.

A process in which the cartridge 2B is attached to the apparatus body 2A will be described with reference to <FIG> are cross-sectional views for describing the process of attachment of the cartridge 2B and are views along arrow VC. The driving-side guide <NUM> and the drum bearing <NUM> are illustrated in a simplified manner. Moreover, the arrow view VC is a view illustrating the state of the movable slider <NUM> and the movable cam <NUM> on a side closer to the downstream side than the upstream side in the attachment direction C of the cartridge 2B in the cross-sectional view.

First, as illustrated in <FIG>, the distance 73r of the cartridge 2B is the same as the distance 15r of the apparatus body A. Due to this, when the cartridge 2B is attached to the apparatus body 2A, the cartridge 2B enters in the attachment direction C while the identification target boss <NUM> is guided to the second guide portion 218a and the rotation-stopping target portion 273c is guided to the driving-side guide portion 215d.

By doing so, as illustrated in <FIG>, the identification target boss <NUM> abuts on the abutting surface 240a of the slider <NUM>. When the cartridge 2B is moved in the attachment direction C in this state, the identification target boss <NUM> applies a force F4 originating from the attachment force of the cartridge 2B to the abutting surface 240a.

With this force F4, as illustrated in <FIG>, the movable slider <NUM> moves in the direction indicated by arrow M2 while resisting the biasing force of the slider spring <NUM> and the cartridge 2B can enter further into the apparatus body 2A. In this case, the movable cam <NUM> turns in the direction indicated by arrow Q2 with movement of the movable slider <NUM> and moves up to the second allowable position at which the attachment path G2 of the abutting target portion 273f of the cartridge 2B is released.

When the cartridge 2B is inserted further, as illustrated in <FIG>, the identification target boss <NUM> passes through the movable slider <NUM> in a state in which the movable slider <NUM> is moved in the direction indicated by arrow M2. In this case, since contact between the movable slider <NUM> and the identification target boss <NUM> disappears, the movable cam <NUM> starts turning in the direction indicated by arrow Q1 by the biasing force of the slider spring <NUM>. The capacitance abutting portion 241d abuts on the driving-side end surface <NUM> of the drum bearing <NUM> whereby turning of the movable cam <NUM> stops.

When the cartridge 2B is inserted further, the cartridge 2B reaches an attachment completion position illustrated in <FIG> as described above with respect to the apparatus body 2A. That is, the upper positioning target portion 273d, the lower positioning target portion 273f, and the rotation-stopping target portion 273c of the cartridge 2B abut on the upper positioning portion 215a, the lower positioning portion 215b, and the rotation-stopping portion 215c of the apparatus body 2A, respectively, whereby attachment is completed.

To summarize the above description, when the cartridge 2B that is allowed to be attached to the apparatus body 2A is inserted, the identification target boss <NUM> passes through the second guide portion 218a. When the cam regulating portion 241a (the movable cam <NUM>) is moved to the second allowable position with the aid of the movable slider <NUM>, the cartridge 2B can enter the apparatus body 2A while preventing the abutting target portion 273f from abutting on the cam regulating portion 241a.

A process of preventing an attachment error of a cartridge D3 (a third unallowed cartridge) to the apparatus body 2A using the second driving-side attachment error prevention mechanism will be described with reference to <FIG> are cross-sectional views for describing the process of attachment of the cartridge D3, in which the driving-side guide <NUM> of the apparatus body 2A and the drum bearing <NUM> of the cartridge D3 are illustrated in a simplified manner.

As illustrated in <FIG>, the cartridge D3 is configured such that the distance 74r between an identification boss <NUM> and a rotation-stopping target portion 274c is narrow unlike the distance 73r of the cartridge 2B. When the cartridge D3 is inserted in the direction indicated by arrow C, the distance 74r is different from the distance 15r of the apparatus body. Therefore, as illustrated in <FIG>, the drum bearing <NUM> interferes with the driving-side guide <NUM> or the second guide rail <NUM> and the cartridge D3 cannot enter the attachment portion S. In this way, attachment of the cartridge D3 can be regulated.

That is, the second guide portion 218a of the second guide rail <NUM> has an inlet shape corresponding to the outer shape of the identification target boss <NUM> of the cartridge 2B when seen in the attachment direction of the cartridge to the apparatus body 2A. A regulating wall that abuts on the identification boss <NUM> of the cartridge D3 is formed around the inlet. Second identification of whether a cartridge that is to be attached to the apparatus body 2A is allowed one or not is realized by the second guide rail <NUM> as the second identifying portion, the identification target boss <NUM> and the identification target boss <NUM> as the second identification target portion provided in the cartridge 2B or D4.

A process of preventing an attachment error of still another cartridge D4 (a fourth unallowed cartridge) will be described with reference to <FIG> are cross-sectional views for describing the process of attachment of the cartridge D4 and are views along arrow VC. The driving-side guide <NUM> of the apparatus body 2A and the drum bearing <NUM> of the cartridge D4 are illustrated in a simplified manner. Moreover, the arrow view VC is a view illustrating the state of the movable slider <NUM> and the movable cam <NUM> on a side closer to the downstream side than the upstream side in the attachment direction C of the cartridge D4 in the cross-sectional view.

As illustrated in <FIG>, the cartridge D4 includes the drum bearing <NUM> (having the rotation-stopping target portion 275c only) that does not have the identification target boss <NUM> of the cartridge 2B. Due to this, when the cartridge D4 is inserted in the attachment direction C, as illustrated in <FIG>, the cartridge D4 can proceed in the attachment direction C while preventing the drum bearing <NUM> from interfering with the driving-side guide <NUM> and the second guide rail <NUM>. However, when the cartridge D4 is inserted in this state, the cartridge D4 enters while preventing the drum bearing <NUM> from abutting on the abutting surface 240a of the movable slider <NUM>. By doing so, in a state in which the cam regulating portion 241a is at the second regulation position, the abutting target portion 275f of the cartridge D4 comes into contact with the cam regulating portion 241a. In this way, a force F5 originating from the attachment force of the cartridge D4 is applied to the cam regulating portion 241a from the abutting target portion 275f. By doing so, the movable cam <NUM> is immovable from the second regulation position and the attachment path G2 remains in a blocked state. Since the force F5 acts in a direction orthogonal to the moving direction of the movable cam <NUM> and the movement of the movable cam <NUM> is regulated by the movable slider <NUM>, the movable cam <NUM> does not move in a state of blocking the attachment path G2. In this way, it is possible to regulate attachment of the cartridge D4.

That is, fourth identification of whether a cartridge that is to be attached to the apparatus body 2A is allowed one or not is realized by the cam regulating portion 241a as the fourth identifying portion and the abutting target portion 273f of the cartridge D4 as the fourth identification target portion.

As described above, using the second attachment error prevention mechanism provided on the other end side (the driving side) of a cartridge, it is possible to allow attachment of an allowed cartridge and regulate attachment of an unallowed cartridge (a third or fourth unallowed cartridge).

In addition to the first attachment error prevention mechanism, only the cartridge 2B being allowed by both the first and second attachment error prevention mechanisms is allowed to be attached to the apparatus body 2A. In contrast, a cartridge (the cartridges D1 to D4) determined to be not allowed by either one of the first and second attachment error prevention mechanisms is regulated from being attached to the apparatus body 2A.

More specifically, the cartridges D1 to D4 are determined to correspond to either one of (i) the first unallowed case and (ii) the second unallowed case by either one of the attachment error prevention mechanisms, and attachment to the apparatus body 2A is regulated. The first unallowed case is a case in which attachment at a first attachment position on the uppermost side in the attachment path is regulated. The second unallowed case is a case in which, although a cartridge can pass through a first attachment position, attachment at a second attachment position closer to the upstream side than the attachment completion position is regulated, and the cartridge cannot reach the attachment completion position. Therefore, by performing identification individually at both ends in the longitudinal direction, it is possible to increase the number of allowed and unallowed identification patterns.

In the present embodiment, a non-driving-side identification pattern (a combination of the first identifying portion and the first identification target portion) is arranged such that it is identified whether the positions in the longitudinal direction Y of a cartridge match each other. Moreover, a driving-side identification pattern (a combination of the second identifying portion and the second identification target portion) is arranged such that it is identified whether the positions in the up-down direction Z of a cartridge match each other. However, the identification pattern is not limited to this configuration, but an arrangement direction of an identification pattern can be selected arbitrarily depending on an arrangement space of the attachment error prevention mechanism. As a result, a plurality of attachment error prevention mechanisms can be disposed in order to improve the space efficiency of the apparatus body 2A.

Claim 1:
An image forming apparatus which comprises an apparatus body (A) and a cartridge (B) detachably attachable to the apparatus body in an attachment direction, the image forming apparatus forming an image on a recording material when the cartridge is at an attachment completion position of the apparatus body, wherein
the cartridge (B) includes a portion-to-be-positioned (71d) and an engagement portion (71p),
the apparatus body (A) includes:
a positioning portion (16a) that abuts on the portion-to-be-positioned (71d) of the cartridge to position the cartridge with respect to the apparatus body when the cartridge is at the attachment completion position;
a first guide portion (16f) that guides the engagement portion (71p) of the cartridge and has an inlet having a shape corresponding to an outer shape of the engagement portion as seen in the attachment direction and allowing a passage of the engagement portion of the cartridge;
a second guide portion (16d) that guides the portion-to-be-positioned (71d) of the cartridge toward the positioning portion (16a); and
a movable member (<NUM>) configured to be pressed by the engagement portion (71p) of the cartridge, which passes through the inlet of the first guide portion (16f), with movement of the cartridge toward the attachment completion position whereby the movable member (<NUM>) is rotated, about a rotation axis (H) orthogonal to the attachment direction, from a first position at which the movable member (<NUM>) blocks a guiding path of the portion-to-be-positioned (71d) in the second guide portion (16d) to a second position at which the movable member (<NUM>) does not block the guiding path,
wherein the portion-to-be-positioned (71d) of the cartridge is moved to a downstream side of the movable member (<NUM>) in the attachment direction while the movable member (<NUM>) is at the second position, thereby the cartridge reaching the attachment completion position, and wherein the movable member at the first position is configured to be immovable from the first position unless being pressed by the engagement portion.