Cartridge

A cartridge including: a housing including a first side wall and a second side wall which are opposed to each other; a driving input member provided to the first side wall and is configured to rotate; and a first rotary member provided at an outer side of the first side wall and is configured to rotate about a first rotational axis in response to a rotational driving force from the driving input member, wherein the first rotary member includes a protrusion protruding to the outer side, wherein the first rotary member is configured to be moved relative to the first side wall in a direction along the first rotational axis, and wherein an end portion of the first rotary member at an opposite side of the first side wall is configured to be displaced in a direction crossing the first rotational axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Patent Application No. 2011-100507 filed on Apr. 28, 2011, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

Aspects of the present invention relate to a cartridge for an image forming apparatus such as a laser printer.

BACKGROUND

In an example of a laser printer, a developing cartridge is mounted in an apparatus body. Toner is accommodated in the developing cartridge. The toner in the developing cartridge is used to form an image on sheet. If there is no toner in the developing cartridge, the developing cartridge is removed from the apparatus body and a new developing cartridge is mounted in the apparatus body. Further, when sheet jam occurs in the apparatus body, the developing cartridge is removed from the apparatus body. And, after the sheet jam is solved, the developing cartridge is mounted again in the apparatus body.

In order to determine the service life of the developing cartridge, a technique for determining whether the developing cartridge mounted in the apparatus body is a new product or an old product has been proposed.

A detecting gear is provided to a side surface of the developing cartridge. The detecting gear is configured to rotate about an axis (rotational axis) extending in a direction perpendicular to the side surface. The detecting gear includes a plate-shaped detecting gear body and an abutting protrusion integrally formed with the detecting gear body. Herein, the abutting protrusion is provided outside (an opposite side of the developing cartridge's side surface relative to the detecting gear body) of the detecting gear body. The detecting gear body is provided with gear teeth over a partial peripheral surface thereof.

Further, a transmitting gear is provided to the side surface of the developing cartridge. The transmitting gear is configured to rotate about an axis extending parallel to and spaced apart from the axis of the detecting gear. The transmitting gear is integrally rotated together with an agitator for agitating the toner in the developing cartridge. The transmitting gear includes gear teeth over an entire peripheral surface thereof.

In a new developing cartridge, the gear teeth of the transmitting gear is engaged with the gear teeth of the detecting gear. When the developing cartridge is mounted in the apparatus body, a driving force of the motor is inputted to the transmitting gear and then transmitted from the transmitting gear to the detecting gear owing to the engagement between the gear teeth of the transmitting gear and the gear teeth of the detecting gear.

Therefore, the detecting gear rotates and the abutting protrusion moves in a rotational direction of the detecting gear in accordance with the rotation of the detecting gear. When the detecting gear is continuously rotated and a part of the detecting gear without teeth is opposed to the gear teeth of the transmitting gear, the engagement between the gear teeth of the transmitting gear and the gear teeth of the detecting gear is released and thus the detecting gear stops rotating. Accordingly, when the developing cartridge has been mounted in the apparatus body at least once, the engagement between the gear teeth of the transmitting gear and the gear teeth of the detecting gear is released and this state is maintained.

A sensor for detecting passing of the abutting protrusion as a detected protrusion is provided in the apparatus body. It is determined whether the developing cartridge is a new product or an old product, based on the detecting result of the sensor. That is, when the developing cartridge is mounted in the apparatus body and then the sensor detects the passing of the abutting protrusion, it is determined that the developing cartridge is a new product. On the contrary, when the developing cartridge is mounted in the apparatus body and then the sensor does not detect the passing of the abutting protrusion, it is determined that the developing cartridge is an old product (Refer to, for example, JP-A-2006-267994).

SUMMARY

However, when the developing cartridge is attached to or detached from the apparatus body or when the developing cartridge is separated from the apparatus body and transported, there is a risk that the abutting protrusion is worn by rubbing with other components. Further, there is a risk that the abutting protrusion and/or other components can be damaged, due to contact or engagement of the abutting protrusion and other components.

The object of aspects of the present invention is to provide a cartridge capable of reducing the wear on the detected protrusion.

According to an aspect of the invention, there is provided a cartridge including: a housing including a first side wall and a second side wall which are opposed to each other and accommodating developer therein; a driving input member provided to the first side wall and is configured to rotate by a rotational driving force inputted from the outside; and a first rotary member provided at an outer side of the first side wall and is configured to rotate about a first rotational axis in response to a rotational driving force from the driving input member, wherein the first rotary member includes a protrusion protruding to the outer side, wherein the first rotary member is configured to be moved relative to the first side wall in a direction along the first rotational axis, and wherein an end portion of the first rotary member at an opposite side of the first side wall is configured to be displaced in a direction crossing the first rotational axis.

According thereof, the driving input member is provided to the first side wall of the housing of the cartridge. The driving input member is rotated by the rotational driving force inputted from the outside. As the driving input member rotates, the rotational driving force is outputted from the driving input member.

The cartridge includes a first rotary member rotating in response to the rotational driving force outputted from the driving input member. The first rotary member has a detected protrusion protruding outward. And, the first rotary member is provided at the outer side of the first side wall and is configured to be moved relative to the first side wall in a direction along the first rotational axis and to allow an end portion thereof at an opposite side of the first side wall to be displaced in a direction crossing the first rotational axis.

Therefore, when other components contact the detected protrusion to apply a force to the detected protrusion during the transportation of the cartridge, the first rotary member is displaced in a direction along the first rotational axis and/or a direction crossing the first rotational axis. Accordingly, it is possible to prevent a strong force from being applied to the detected protrusion and to reduce the wear on the detected protrusion. Further, the force applied to the detected protrusion can be relieved and thus the damage to the detected protrusion can be alleviated.

According to another aspect of the invention, there is provided a cartridge including: a housing accommodating developer therein, the housing including, a first side all and a second side wall which is opposed to a first surface of the first side wall; a driving input member provided to the first side wall and is configured to rotate; a first rotary member opposed to a second surface of the first side wall, which is opposite to the first surface of the first side wall, at a first surface thereof, and is configured to rotate about a first rotational axis in response to a rotational driving force from the driving input member, the first rotational axis being substantially perpendicular to the first side wall; and a protrusion protruding from a second surface of the first rotary member, which is opposite to the first surface of the first rotary member, wherein the first rotary member is configured to be moved relative to the first side wall in a direction substantially parallel to the first rotational axis, and wherein the first rotary member is configured to be displaced in a direction crossing the first rotational axis.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will be described in detail by referring to accompanying drawings.

First Exemplary Embodiment

1. Overall Configuration of a Laser Printer

As illustrated inFIG. 1, the laser printer1includes a body casing2(apparatus body). A front side wall of the body casing2includes a cartridge removable opening3and a front cover4for opening and closing the cartridge removable opening3.

It should be noted that the front face side of the laser printer1is referred to the front side in a front-rear direction. Further, an upper-lower direction and a left-right direction of the laser printer1and the developing cartridge7are defined by viewing the laser printer1which is placed on a plane and a developing cartridge7(described later) which is mounted in the body casing2of the laser printer1from the front side of the laser printer and the developing cartridge.

A process cartridge5is mounted slightly in front of the center portion in the body casing2. The process cartridge5can be mounted to the body casing2and separated from the body casing2through the cartridge removable opening3when the front cover4is opened.

The process cartridge5includes a drum cartridge6and the developing cartridge7as an example of a cartridge which is detachably mounted to the drum cartridge6.

The drum cartridge6includes a drum frame8. A photosensitive drum9is rotatably retained on a rear end of the drum frame8. Further, a charger10and a transfer roller11are retained on the drum frame8. The charger10and the transfer roller11are respectively disposed upper to and lower to the photosensitive drum9.

A part of the drum frame8which is placed in front of the photosensitive drum9is referred to as a cartridge mounting part12. The developing cartridge7is mounted to the cartridge mounting part12.

The developing cartridge7includes a housing13which accommodates toner. A toner accommodating chamber14and a developing chamber15are formed in the housing13and are disposed adjacent to each other in a front-rear direction while being communicated to each other.

An agitator16is provided in the toner accommodating chamber14so as to rotate about a rotational axis17of the agitator extending in a left-right direction. As the agitator16rotates, the toner accommodated in the toner accommodating chamber14is agitated and transmitted from the toner accommodating chamber14to the developing chamber15.

A developing roller18and a supply roller19are provided in the developing chamber15so as to rotate about a rotational axis20of the developing roller and a rotational axis21of the supply roller respectively extending in a left-right direction.

The developing roller18is arranged so that a portion of the peripheral surface thereof is exposed from the rear end of the housing13. The developing cartridge7is mounted to the drum cartridge6so as to allow the peripheral surface of the developing roller18to contact the peripheral surface of the photosensitive drum9.

The supply roller19is arranged so that the peripheral surface thereof contacts the peripheral surface of the developing roller18from the front lower side. The toner in the developing chamber15is supplied to the peripheral surface of the developing roller18by the supply roller19and carried in a thin layer on the peripheral surface of the developing roller18.

Further, an exposure unit22having a laser is arranged upper to the process cartridge5in the body casing2.

During an image forming operation, the photosensitive drum9rotates at a constant speed in a clockwise direction, as viewed from the left side. As the photosensitive drum9rotates, the peripheral surface (surface) of the photosensitive drum9is uniformly charged with the discharge of the charger10. Meanwhile, the exposure unit22is controlled based on image data and a laser beam is emitted from the exposure unit22. For example, the laser printer1is connected to a personal computer (not illustrated) and the image data is transmitted from the personal computer to the laser printer1. The laser beam passes through the charger10and the developing cartridge7and is irradiated over the uniformly charged peripheral surface of the photosensitive drum9to selectively expose the peripheral surface of the photosensitive drum9. Charges are selectively removed from the exposed portion of the photosensitive drum9by such an exposure to form an electrostatic latent image on the peripheral surface of the photosensitive drum9. When the photosensitive drum9rotates to cause the electrostatic latent image to be opposed to the developing roller18, the toner is supplied from the developing roller18to the electrostatic latent image to develop the electrostatic latent image into a toner image.

A sheet feeding tray23accommodating sheet P is arranged in a bottom portion of the body casing2. A pickup roller24is provided upper to the sheet feeding tray23for feeding sheet from the sheet feeding tray23.

Further, a conveying path25having S-shape as viewed from the side is formed in the body easing2. This conveying path25extends from the sheet feeding tray23to a sheet discharge tray26through between the photosensitive drum9and the transfer roller11. The sheet discharge tray26is formed to an upper surface of the body casing2.

Owing to the action of a bias supplied to the transfer roller11, the toner image on the peripheral surface of the photosensitive drum9is transferred on the sheet P passing through between the photosensitive drum9and the transfer roller11.

A fixing unit27is provided upper to the conveying path25at a position downstream the transfer roller11in the feeding direction of the sheet P. The toner image is transferred on the sheet P and this sheet P is conveyed on the conveying path25and passes over the fixing unit27. In the fixing unit27, the toner image is subjected to heat and pressure and a printed image is formed and is fixed on the sheet P. In this way, the sheet P having the printed image is further conveyed in the conveying path25and discharged on the sheet discharge tray26.

2. Developing Cartridge

The housing13of the developing cartridge7includes a first side wall41(see,FIG. 2) and a second side wall42(see,FIG. 1) which are laterally spaced apart and opposed to each other, as illustrated inFIGS. 1 and 2.

2-2. Gear Train

As illustrated inFIGS. 2 and 3, a gear cover43as an example of a cover is attached to an outer surface (left side) of the first left side wall41. A gear train44is provided inside of the gear cover43, as illustrated inFIG. 4. The gear train44includes an input gear45as an example of a driving input member, a developing gear46, a supply gear47, an intermediate gear48, an agitator gear49and a reset gear50as an example of a second rotary member.

2-2-1. Input Gear

The input gear45is disposed on an upper portion of the front end of the first side wall41, as illustrated inFIG. 4. The input gear45is provided to rotate about an input gear rotating shaft51(see,FIG. 3) extending in a left-right direction. The input gear rotating shaft51is retained on the first side wall41so as not to rotate.

The input gear45integrally includes a large diameter gear part52, a small diameter gear part53and a coupling part54. The large diameter gear part52, the small diameter gear part53and the coupling part54are arranged in this order from the first side wall41.

The large diameter gear part52has a disc shape and a center axis thereof matches a center axis of the input gear rotating shaft51. A plurality of gear teeth are formed on an entire peripheral surface of the large diameter gear part52.

The small diameter gear part53has a disc-shape and a center axis thereof matches the center axis of the input gear rotating shaft51and has a diameter smaller than that of the large diameter gear part52. A plurality of gear teeth are formed on an overall peripheral surface of the small diameter gear part53.

The coupling part54has a columnar shape and a center axis thereof matches the center axis of the input gear rotating shaft51and a peripheral surface thereof has a diameter smaller than that of the peripheral surface of the small diameter gear part53. Coupling recess55is formed on a left side of the coupling part54. An end portion of a driving output member56(see,FIG. 2) which is provided in the body casing2is inserted into the coupling recess55when the developing cartridge7is mounted in the body casing2.

The driving output member56is provided to advance and retreat in a left-right direction. The driving output member56advances to the right side and an end portion thereof is inserted into the coupling recess55, in a state where the developing cartridge7is mounted in the body casing2. Thereby, the driving output member56is coupled to the coupling recess55so as not to allow relative rotation therebetween. Accordingly, as the driving output member56rotates, the rotational force of the driving output member56is transmitted to the input gear45as a driving force and thus the input gear45rotates together with the driving output member56.

2-2-2. Developing Gear

As illustrated inFIG. 4, the developing gear46is disposed below the rear side of the input gear45. The developing gear46is attached to a developing roller shaft57(see,FIG. 3) of the developing roller18so as not to allow relative rotation therebetween. The developing roller shaft57is provided to rotate relative to the first side wall41and has a center axis which corresponds to the rotational axis20(see,FIG. 1) of the developing roller18. The developing gear46includes gear teeth over entire peripheral surface thereof and the gear teeth are engaged with the gear teeth of the large diameter gear part52of the input gear45.

2-2-3. Supply Gear

As illustrated inFIG. 4, the supply gear47is disposed below the input gear45. The supply gear47is attached to a supply roller shaft58(see,FIG. 1) of the supply roller19so as not to allow relative rotation therebetween. The supply roller shaft58is provided to rotate relative to the first side wall41and has a center axis which corresponds to the rotational axis21(see,FIG. 1) of the supply roller19. The supply gear47includes gear teeth over an entire peripheral surface thereof and the gear teeth are engaged with the gear teeth of the large diameter gear part52of the input gear45.

2-2-4. Intermediate Gear

As illustrated inFIG. 4, the intermediate gear48is disposed above the front side of the input gear45. The intermediate gear48is provided to rotate about a center axis of an intermediate gear rotating shaft59extending in a left-right direction. The intermediate gear rotating shaft59is non-rotatably retained on the first side wall41.

And, the intermediate gear48integrally includes a small diameter part60and a large diameter part61. The small diameter part60has a disc shape of which outer diameter is relatively small and the large diameter part61has a cylindrical shape of which outer diameter is relatively large. The small diameter part60and the large diameter part61are arranged in this order from the first side wall41. Each center axis of the small diameter part60and the large diameter part61matches to the center axis of the intermediate gear rotating shaft59.

The small diameter part60includes gear teeth over entire peripheral surface thereof.

The large diameter part61includes gear teeth over entire peripheral surface thereof. The gear teeth of the large diameter part61are engaged with the gear teeth of the small diameter gear part53of the input gear45.

As illustrated inFIG. 4, the agitator gear49is disposed below the front side of the intermediate gear48. The agitator gear49is attached to an agitator rotating shaft62so as not to allow relative rotation therebetween. The agitator rotating shaft62passes through the first side wall41and the second side wall42(see,FIG. 1) in the left-right direction and rotatably retained on the first side wall41and the second side wall42. The agitator16is attached to the agitator rotating shaft62in the housing13. Thereby, the agitator16and the agitator gear49can rotate integrally with the agitator rotating shaft62while using the center axis of the agitator rotating shaft62as the rotational axis17(see,FIG. 1) of the agitator.

Further, the agitator gear49integrally includes a large diameter gear part64and a small diameter gear part65.

The large diameter gear part64has a disc shape of which center axis matches to the agitator rotating shaft62. The large diameter gear part64includes gear teeth over entire peripheral surface thereof. The gear teeth of the large diameter gear part64are engaged with the gear teeth of the small diameter part60of the intermediate gear48.

The small diameter gear part65is formed at a side opposite to the first side wall41relative to the large diameter gear part64and has a disc shape of which center axis matches to the agitator rotating shaft62. The small diameter gear part65has a diameter smaller than that of the large diameter gear part64. The small diameter gear part65includes gear teeth66over entire peripheral surface thereof.

2-2-6. Reset Gear

As illustrated inFIG. 4, the reset gear50is disposed above the front side of the agitator gear49. The reset gear50is provided to rotate about a support shaft67extending in a left-right direction, as illustrated inFIG. 5.

As an example of a support member, the support shaft67is retained on the first side wall41so as not to rotate.

The reset gear50integrally includes a right cylindrical fitting part70as an example of a third fitted part and a teeth missing gear part71.

The right cylindrical fitting part70has a cylindrical shape of which inner diameter is substantially same as the outer diameter of the support shaft67. The support shaft67is inserted into the right cylindrical fitting part70so as to allow relative rotation therebetween. Thereby, the reset gear50is rotatably supported on the support shaft67as a support point.

The teeth missing gear part71has a disc shape which protrudes from a middle portion in a direction (left-right direction) of the center axis of the right cylindrical fitting part70. The disc shape of the missing gear part71protrudes in a diametric direction of the right cylindrical fitting part70. As illustrated inFIG. 4, the teeth missing gear part71includes gear teeth72over a portion of the peripheral surface thereof. Specifically, in the peripheral surface of the teeth missing gear part71, a part having a central angle of about 185° is provided as a teeth missing part73and a part other than the teeth missing part73having a central angle of about 175° includes the gear teeth72. The gear teeth72are engaged with the gear teeth66of the small diameter gear part65of the agitator gear49depending upon a rotational position of the reset gear50.

2-3. Detected Rotary Member

As illustrated inFIGS. 4,5and6, a detected rotary member74as an example of the first rotary member is provided to a left side (outer side) of the reset gear50.

The detected rotary member74integrally includes a main body75, a left cylindrical fitting part76as an example of a third fitting part and a detected protrusion part77as an example of the protrusion.

The main body75has a thin disc shape. As illustrated inFIGS. 4 and 5, the main body75is provided at its center portion with a through hole78having a circular shape concentric with the main body75.

The left cylindrical fitting part76has a cylindrical shape protruding to the right from the periphery of the through hole78. The end portion of the left cylindrical fitting part76is loosely inserted into the end portion of the right cylindrical fitting part70of the reset gear50, as illustrated inFIG. 5. That is, a right end of the left cylindrical fitting part76is inserted into a left end of the right cylindrical fitting part70. Further, a space is provided at a part where the right cylindrical fitting part70and the left cylindrical fitting part76oppose in a front-rear direction. Thereby, the detected rotary member74is provided to allow the left end thereof to be movable in a direction along a center axis671of the support shaft67and displaceable in a direction crossing the center axis671as an example of the first rotational axis.

Further, as illustrated inFIG. 7, in the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76, the right cylindrical fitting part70and the left cylindrical fitting part76have a D shaped cross-section. Thereby, the right cylindrical fitting part70and the left cylindrical fitting part76have an allowance by the space therebetween and are engaged with each other so as not to allow relative rotation therebetween.

The detected protrusion part77protrudes to the left from a left end surface of the main body75. As illustrated inFIG. 3, the detected protrusion part77includes a semicircular arc-shaped plate which is curved along the peripheral edge of the main body75, as viewed from the left side. Further, as illustrated inFIG. 5, the detected protrusion part77includes a first protruding portion79and a second protruding portion80which have a substantially triangular shape, as viewed in the diametric direction of the main body75. That is, an end771of the detected protrusion part77in a rotational direction R of the detected rotary member74is chamfered. Further, an end772(outer end and inner end) of the detected protrusion part77in a thickness direction (diametric direction of the main body75) thereof is also chamfered.

2-4. Coil Spring

A coil spring81as an example of an elastic member is interposed in a compressed state between the reset gear50and the detected rotary member74, as illustrated inFIGS. 4 to 6. The coil spring81surrounds the peripheries of the right cylindrical fitting part70and the left cylindrical fitting part76. The coil spring includes one end contacting the teeth missing gear part71of the reset gear50and the other end contacting the main body75of the detected rotary member74. The coil spring81causes the detected rotary member74to be urged in a direction away from the reset gear50, that is, to be urged to the left.

2-5. Gear Cover

As illustrated inFIG. 2, the gear cover43integrally includes an opposing wall82opposing to the first side wall41from the left side and a peripheral wall83extending from a peripheral edge of the opposing wall82toward the first side wall41. The gear cover43is made of resin material, for example.

The opposing wall82includes an opposing part84opposing to the reset gear50from the left side, as illustrated inFIG. 5. The opposing part84has a circular shape as viewed from the side and has a recess shape with one step on a side (left side) opposite to the first side wall41. The detected rotary member74is accommodated in the opposing part84. A peripheral wall841of the opposing part84as an example of the first fitted part is spaced apart and opposed to the detected rotary member74in the diametric direction of the opposing part84.

The opposing part84includes a large circular opening86while remaining a peripheral edge85thereof. The peripheral edge of the main body75of the detected rotary member74contacts the peripheral edge85of the opposing part84from the inner side. Thereby, the detected protrusion part77of the detected rotary member74protrudes outward through the opening86while preventing the detected rotary member74from coming out from the opposing part84.

Further, the opposing wall82includes an opening91for exposing the coupling part54of the input gear45, as illustrated inFIG. 3.

3. Detecting New Developing Cartridge

In new developing cartridge7, as illustrated inFIGS. 4 and 6, the gear teeth72in most downstream side of a rotational direction R (described later) out of the gear teeth72of the reset gear50are engaged with the gear teeth66of the agitator gear49.

As the developing cartridge7is mounted in the body casing2, a warm-up operation of the laser printer1is started. In this warm-up operation, the driving output member56(see,FIG. 2) is inserted into the coupling part54(coupling recess55) of the input gear45and thus a driving force from the driving output member56is inputted to the input gear45to allow the input gear45to be rotated. And, as the input gear45rotates, the developing gear46, the supply gear47and the intermediate gear48rotate and thus the developing roller and the supply roller19rotate. Further, the intermediate gear48rotates, the agitator gear49rotates and then the agitator16(see,FIG. 1) rotates. As the agitator16rotates, the toner in the developing cartridge7is agitated.

In new developing cartridge7, the gear teeth66of the agitator gear49and the gear teeth72of the reset gear50are engaged with each other. Accordingly, as the agitator gear49rotates, the reset gear50is driven by the rotation of the agitator gear and rotates in the rotational direction R of a counter-clockwise direction as viewed from the left side. And, as the reset gear50rotates, the detected rotary member74rotates in the rotational direction R.

As the detected rotary member74rotates, the detected protrusion part77moves in the rotational direction R. Herein, a sensor (not illustrated) is provided in the body casing2. For example, the configuration of the sensor is disclosed in JP-A-2006-267994. During the movement of the detected protrusion part, the first protruding portion79and the second protruding portion80of the detected protrusion part77subsequently passes through the detecting position of the sensor. As the first protruding portion79and the second protruding portion80reach the detecting position, the sensor outputs On signal. And, as the first protruding portion79and the second protruding portion80completely passes through the detecting position, the sensor stops outputting the On signal (Off signal is outputted).

Thereafter, as the reset gear50further rotates, the engagement between the gear teeth72of the reset gear50and the gear teeth66of the agitator gear49is released and the teeth missing part73of the reset gear50is opposed to the gear teeth66. Thereby, the reset gear50stops rotating and thus the detected rotary member74stops rotating.

In this way, as a new developing cartridge7is firstly mounted in the body casing2, a sensor (not illustrated) outputs the On signal twice. Accordingly, when the sensor (not illustrated) outputs the On signal twice after the developing cartridge7is mounted in the body casing2, it is determined that the developing cartridge7is new.

Meanwhile, when an old developing cartridge7(herein, the old developing cartridge7is defined as a developing cartridge7which has been mounted to the body casing2at least once) is mounted in the body casing2, the reset gear50is positioned to such that the engagement between the gear teeth72, and the gear teeth66is released. Accordingly, even though the warm-up operation of the laser printer1is started, the reset gear50does not rotate. Accordingly; when the sensor (not illustrated) does not output the On signal within a predetermined period from the time point when the developing cartridge7is mounted in the body casing2, it is determined that the developing cartridge7is old.

As mentioned above, the input gear45is provided to the first side wall41of the housing13of the developing cartridge7. The input gear45is rotated by the rotational driving force inputted from the outside. As the input gear45rotates, the rotational driving force is outputted from the input gear45.

The developing cartridge7includes the detected rotary member74which rotates in response to the rotational driving force outputted from the input gear45. The detected rotary member74includes the detected protrusion part77protruding outward. And, the detected rotary member74is provided to the outer side of the first side wall41and is configured to be moved relative to the first side wall41in a direction along the center axis671of the support shaft67extending in a left-right direction and to allow an end portion (left end portion) thereof at an opposite side of the first side wall41to be displaced in a direction crossing the center axis671.

Therefore, when other components contact the detected protrusion part77to apply a force on the detected protrusion part77during the transportation of the developing cartridge7, as illustrated inFIGS. 8,9A and9B, the detected rotary member74is displaced in a direction along the center axis671and/or a direction crossing the center axis671. Accordingly, it is possible to prevent a strong force from being applied to the detected protrusion part77and to reduce the wear of the detected protrusion part77. Further, the force applied to the detected protrusion part77can be relieved and thus the damage of the detected protrusion part77can be avoided.

The gear cover43is attached to the first side wall41. The gear cover43includes the opposing part84which is opposed to the detected rotary member74from the opposite side (outer side) of the first side wall41. Accordingly, it is possible to prevent the detected rotary member74from coming out outwardly.

The detected rotary member74includes the left cylindrical fitting part76extending in a direction along the center axis671. Meanwhile, the gear cover43includes the peripheral wall841which is spaced apart and opposed to the left cylindrical fitting part76in a direction perpendicular to the direction along the center axis671. Thereby, it is possible to prevent the detected rotary member74from coming out and to allow the detected rotary member74to be displaced in a direction crossing the center axis671.

The reset gear50is provided to the first side wall41and is configured to rotate about the center axis671. The detected rotary member74is provided to the opposite side of the first side wall41relative to the reset gear50. The rotational driving force is outputted from the input gear45and transmitted to the detected rotary member74by the reset gear50.

The reset gear50includes the right cylindrical fitting part70which is spaced apart and opposed to the left cylindrical fitting part76in a direction perpendicular to the direction along the center axis671. Thereby; it is possible to allow the detected rotary member74to be displaced in a direction crossing the center axis671.

As the detected rotary member74is displaced in a direction crossing the center axis671, the left cylindrical fitting part76and the right cylindrical fitting part70contacts with each other at one point. Specifically, the end portion (left end) of the right cylindrical fitting part70and the end portion (right end) of the left cylindrical fitting part76contacts with each other at one point. In this case, the end portion (left end) of the right cylindrical fitting part70is considered as an example of a first position and the end portion (right end) of the left cylindrical fitting part76is considered as an example of a second position. More specifically, for example, an approximately center portion of the inner surface of the right cylindrical fitting part70in a left-right direction and the end portion (right end) of the left cylindrical fitting part76contacts with each other at one point (contact point T, seeFIG. 9B). In this case, the approximately center portion of the right cylindrical fitting part70is considered as an example of the first position and the end portion (right end) of the left cylindrical fitting part76is considered as an example of the second position. Thereby, it is possible to allow the detected rotary member74to be displaced in a direction crossing the center axis671.

The coil spring81causes the detected rotary member74to be urged in a direction away from the first side wall41, that is, in a direction where the detected protrusion part77protrudes outwardly. When other components contact the detected protrusion part77to apply a force to the detected protrusion part77, the detected rotary member74is displaced in a direction along the center axis671against the urging force (elastic force) of the coil spring81. Accordingly, only when other components contact the detected protrusion part77, the detected rotary member74can be displaced in a direction where the detected protrusion part77is immersed inwardly.

The detected protrusion part77includes the first protruding portion79and the second protruding portion80which have a substantially triangular plate shape and are provided continuously in the rotational direction R. Thereby, the end771of the detected protrusion part77in the rotational direction R of the detected rotary member74is chamfered.

Further, both ends772of the detected protrusion part77in the thickness direction R thereof are also chamfered. Herein, the thickness direction refers to a diametric direction of the main body75, that is, a diametric direction relative to the rotational direction R.

Therefore, it is possible to effectively prevent the detected protrusion part77from being engaged with other components in the rotational direction R and the diametric direction thereof during the transportation of the developing cartridge7.

Second Exemplary Embodiment

Instead of the configurations illustrated inFIGS. 3 to 9B, configurations illustrated inFIGS. 10,11and12may be employed. InFIGS. 10 to 12, the same or similar element will be denoted by the same reference numeral as that of the first exemplary embodiment.

In the configurations illustrated inFIGS. 10 to 12, instead of the reset gear50and the detected rotary member74illustrated inFIG. 5, a detected gear101having functions of both the reset gear and the detected rotary member is provided.

As illustrated inFIGS. 11 and 12, the detected gear101as an example of the first rotary member integrally includes a main body120, a teeth missing gear part103, a cylindrical fitting part104as an example of a second fitting part and the detected protrusion part77.

The main body102has a cylindrical shape with a closed left end surface. The main body102is provided at its center portion with a through hole106having a circular shape concentric with the main body102.

The teeth missing gear part103has a flange shape which protrudes from a right end of the main body102to the periphery. As illustrated inFIG. 12, the teeth missing gear part103includes gear teeth72partially on the peripheral surface thereof. Specifically, in the peripheral surface of the teeth missing gear part103, a part having a central angle of about 185° is provided as a teeth missing part73and a part other than the teeth missing part73having a central angle of about 175° includes the gear teeth72. The gear teeth72are engaged with the gear teeth66of the small diameter gear part65of the agitator gear49depending upon a rotational position of the reset gear50.

The cylindrical fitting part104has a cylindrical shape protruding to the right direction (direction along the center axis671of the support shaft67) from the periphery of the through hole106. As illustrated inFIG. 11, the support shaft67is inserted into the cylindrical fitting part104so as to allow relative rotation therebetween. Herein, the support shaft67is an example of the support member and the second fitted part. The cylindrical fitting part104has an inner diameter larger than an outer diameter of the support shaft67. Accordingly, a space is provided in the opposed part of an outer peripheral surface of the support shaft67and an inner peripheral surface of the cylindrical fitting part104. Thereby, the detected gear101is rotatably supported on the support shaft67. Also, the detected gear101is provided to allow the left end thereof to be movable in a direction along a center axis671of the support shaft67and displaceable in a direction crossing the center axis671.

A coil spring107as an example of an elastic member is interposed in a compressed state between the first side wall41and the detected gear101. The coil spring107surrounds the peripheries of the support shaft67and the cylindrical fitting part104. The coil spring includes one end contacting the first side wall41and the other end contacting the main body102of the detected gear101. The coil spring107causes the detected gear101to be urged in a direction away from the first side wall41, that is, to be urged to the left.

The support shaft67for rotatably supporting the detected gear101is provided to the first side wall41. The detected gear101includes the cylindrical fitting part104extending in a direction along the center axis671of the support shaft67. The support shaft is spaced apart and opposed to the cylindrical fitting part104in a direction perpendicular to the direction along the center axis671. Thereby, the detected gear101can be displaced in the direction crossing the center axis671while being rotatably supported by the support shaft67.

Therefore, when other components contact the detected protrusion part77to apply a force to the detected protrusion part77during the transportation of the developing cartridge7, the detected gear101is displaced in a direction along the center axis671and/or a direction crossing the center axis671. Accordingly, it is possible to prevent a strong force from being applied to the detected protrusion part77and to reduce the wear to the detected protrusion part77. Further, the force applied on the detected protrusion part77can be relieved and thus the damage of the detected protrusion part77can be alleviated.

As the detected gear101is displaced in a direction crossing the center axis671, the support shaft67and the cylindrical fitting part104contacts with each other at one point. Specifically, the end portion (left end) of the support shaft67and the end portion (right end) of the cylindrical fitting part104contacts with each other at one point. In this case, the end portion (left end) of the support shaft67is considered as an example of a first position and the end portion (right end) of the cylindrical fitting part104is considered as an example of a second position. Thereby, it is possible to allow the detected gear101to be displaced in a direction crossing the center axis671.

Third Exemplary Embodiment

Instead of the configurations illustrated inFIG. 11, configurations illustrated inFIG. 13may be employed. InFIG. 13, the same or similar element will be denoted by the same reference numeral as that of the second exemplary embodiment.

In the configurations illustrated inFIG. 13, the length of the cylindrical fitting part104is short, as compared to the configurations illustrated inFIG. 11and the support shaft67is not inserted into the cylindrical fitting part104.

Similarly, in the configuration illustrated inFIG. 13, the detected gear101is provided to allow the left end thereof to be movable in a direction along a center axis671of the support shaft67and displaceable in a direction crossing the center axis671.

Therefore, when other components contact the detected protrusion part77to apply a force on the detected protrusion part77during the transportation of the developing cartridge7, the detected gear101is displaced in a direction along the center axis671and/or a direction crossing the center axis671. Accordingly, it is possible to prevent a strong force from being applied to the detected protrusion part77and to reduce the wear on the detected protrusion part77. Further, the force applied on the detected protrusion part77can be relieved and thus the damage of the detected protrusion part77can be alleviated.

Hereinabove, the exemplary embodiments of the present invention has been described, but the present invention is not limited thereto and may be practiced in modified embodiments.

In the configuration according to the first embodiment, the left cylindrical fitting part76of the detected rotary member74is loosely inserted into the end portion of the right cylindrical fitting part70of the reset gear50, as illustrated inFIGS. 5 and 9.

Instead of the above configuration, a configuration may be employed in which the left cylindrical fitting part76of the detected rotary member74has an inner diameter larger than an outer diameter of the right cylindrical fitting part70of the reset gear50and an end portion of the right cylindrical fitting part70is inserted into the left cylindrical fitting part76, as illustrated inFIG. 14.

As illustrated inFIG. 15, a configuration may be employed in which two protrusions111are formed on the end portion of the right cylindrical fitting part70of the reset gear50and the detected rotary member74is supported on the right cylindrical fitting part70in such a way that these protrusions111are opposed to the left cylindrical fitting part76of the detected rotary member74to have a slight allowance therebetween

As illustrated inFIG. 16, a configuration may be employed in which two protrusions111are formed on the right cylindrical fitting part70of the reset gear50and the detected rotary member74is supported on the right cylindrical fitting part70in such a way that these protrusions111are opposed to the end portion of the left cylindrical fitting part76of the detected rotary member74to have a slight allowance therebetween,

In the configuration according to the first embodiment, the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76has a D shaped cross-section, as illustrated inFIG. 7.

The cross-sectional shape of the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76is not limited to the D shape and any cross-sectional shape may be employed as long as the right cylindrical fitting part70and the left cylindrical fitting part76are engaged with each other so as not to allow relative rotation therebetween.

For example, the cross-sectional shape of the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76may be a triangular shape as illustrated inFIG. 17(modification 4) or an elliptical shape as illustrated inFIG. 18(modification 5).

Further, as illustrated inFIG. 19, a configuration may be employed in which two sets of the right cylindrical fitting part70and the left cylindrical fitting part76are provided and the cross-sectional shape of the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76is a circular shape (modification 6).

Further, as illustrated inFIG. 20, a configuration may be employed in which the cross-sectional shape of the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76is a circular shape, and one of the right cylindrical fitting part and the left cylindrical fitting part includes a protrusion131and the other includes a groove132capable of being engaged with the protrusion131(modification 7).

Further, as illustrated inFIG. 21, a configuration may be employed in which the cross-sectional shape of the opposed part of the right cylindrical fitting part70and the left cylindrical fitting part76is a circular shape, an engaging part (engaging part501on the reset gear50and engaging part741on the detected rotary member74) is provided as a separate member different from the right cylindrical fitting part70and the left cylindrical fitting part76, and the reset gear50and the detected rotary member74are engaged by the engaging part so as not to allow relative rotation therebetween (modification 8).

Specifically, the engaging part501on the reset gear50has a substantially prismatic shape which extends from the left side of the reset gear50to the left in a region radially outward from the right cylindrical fitting part70.

Further, the engaging part741on the detected rotary member74has a substantially prismatic shape which extends from the right side of the detected rotary member74to the right in a region radially outward from the left cylindrical fitting part76.

As the engaging part501on the reset gear50contacts the engaging part741from the upstream side of the rotational direction R, the detected rotary member74rotates together with the reset gear50in the rotational direction R.

As illustrated inFIG. 22, a space between the right cylindrical fitting part70of the reset gear50and the left cylindrical fitting part76of the detected rotary member74may be expanded toward the left. By this configuration, it is possible to secure a large amount of displacement of the detected rotary member74in a direction crossing the center axis671.

As illustrated inFIG. 23, a space between the support shaft67and the cylindrical fitting part104of the detected gear101may be expanded toward the right. By this configuration, it is possible to secure a large amount of displacement of the detected gear101in a direction crossing the center axis671.

As an example of a cartridge, the developing cartridge7which includes the agitator16(as an example of a supplying member) having the agitator rotating shaft62and the developing roller18having the developing roller shaft57is employed. However, the cartridge may be a toner cartridge which includes the agitator16but does not include the developing roller18or a toner cartridge which does not include the agitator16and the developing roller18. Further, instead of the agitator16, an auger may be used.

In each embodiment and each modification, the reset gear50includes the teeth missing gear part71which has gear teeth72at a partial area thereof (an area excluding the teeth missing part73). However, as illustrated inFIG. 24, for example, a substantially disc-shaped main body141around the center axis671and a resistance providing member142wound around an outer periphery of the main body141may be provided, instead of the teeth missing gear part71. Herein, at least an outer peripheral surface of the resistance providing member142is made of a material having a relatively high frictional coefficient such as a rubber. In this case, the small diameter gear part65of the agitator gear49may include the gear teeth66at its peripheral surface or not. Also, one half of the main body141is a relatively small diameter part142B so that the outer peripheral surface of the resistance providing member142does not contact the small diameter gear part65and the other half of the main body141is a relatively large diameter part142A so that the outer peripheral surface of the resistance providing member142contacts the peripheral surface of the small diameter gear part65.

In each embodiment and each modification, the left cylindrical fitting part76of the detected rotary member74is loosely inserted into the right cylindrical fitting part70of the reset gear50. However, for example, a configuration may be employed in which the left cylindrical fitting part76of the detected rotary member74is made of an elastically deformable material such as a rubber and fitted into the right cylindrical fitting part70of the reset gear50, as illustrated inFIG. 25.

According to the configuration, as other components contact the detected protrusion part77of the detected rotary member74, the left cylindrical fitting part76is elastically deformed and thus a force applied on the detected protrusion part77can be relieved.

The above configurations can be variously modified within the scope of appended claims.